Categorization of Event Sequences for License Application Rev 00B, ICN 00

000-00C-MGR0-00800-000-00B

April 2005

1 PURPOSE 
The purposes of this analysis are: 
 Categorize (as Category 1, Category 2, or Beyond Category 2) internal event sequences 
that may occur before permanent closure of the repository at Yucca Mountain. 
 Categorize external event sequences that may occur before permanent closure of the 
repository at Yucca Mountain. This includes examining DBGM-1 seismic 
classifications and upgrading to DBGM-2, if appropriate, to ensure Beyond Category 2 
categorization. 
 State the design and operational requirements that are invoked to make the 
categorization assignments valid. 
 Indicate the amount of material put at risk by Category 1 and Category 2 event 
sequences. 
 Estimate frequencies of Category 1 event sequences at the maximum capacity and 
receipt rate of the repository. 
 Distinguish occurrences associated with normal operations from event sequences. It is 
beyond the scope of the analysis to propose design requirements that may be required to 
control radiological exposure associated with normal operations. 
 Provide a convenient compilation of the results of the analysis in tabular form 
(Attachment III). 
The results of this analysis are used as inputs to the consequence analyses in an iterative design 
process that is depicted in Figure 1. Categorization of event sequences for permanent retrieval of 
waste from the repository is beyond the scope of this analysis. Cleanup activities that take place 
after an event sequence and other responses to abnormal events are also beyond the scope of the 
analysis. 
An event sequence is defined by the U.S. Nuclear Regulatory Commission to be a series of 
actions and/or occurrences within the natural and engineered components of a geologic 
repository operations area that could potentially lead to exposure of individuals to radiation (10 
CFR 63.2 [DIRS 158535]). The definition further states that an event sequence includes one or 
more initiating events and associated combinations of repository system component failures 
including those produced by the action or inaction of operating personnel. The most frequent 
event sequences, those belonging to Category 1, are expected to occur one or more times before 
permanent closure of the geologic repository operations area (10 CFR 63.2 [DIRS 158535]). 
Category 2 includes the remaining event sequences that have at least one chance in 10,000 of 
occurring before permanent closure (10 CFR 63.2 [DIRS 158535]). Event sequences that do 
not have at least one chance in 10,000 of occurring before permanent closure are categorized as
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 21 April 2005 
Beyond Category 2. An event with no potential for exposure of individuals to radiation, is not 
considered an event sequence. 
As shown by the two decision diamonds near the center of Figure 1, event sequences are 
categorized as Category 1, Category 2, or Beyond Category 2. Descriptions of the Category 1 
and 2 event sequences are inputs to the consequence analyses, as represented by the parallel 
paths proceeding from Event Sequence Categorization. If unacceptable consequences are found, 
design or operational changes may become necessary (as indicated by the feedback loop back up 
to the top). If consequences are acceptable, the structures, systems and components (SSCs) and 
operational features that were credited for the categorization and consequence calculations 
become inputs to the nuclear safety design basis. If some of the design and operational features 
that were credited (as reflected in the Q-List and the system description documents and facility 
description documents) are found less than optimal by design or performance-assessment 
organizations, alternative design or operational features may be adopted (as reflected in the 
second point of entry into the feedback loop to the top). Whenever design or operational features 
are changed, new internal or external event sequences may be identified (as reflected in the box 
at the top of the diagram). 
This document uses the following generic terms. The specific canister or cask name is used as 
required. 
 DOE SNF canister includes standardized DOE SNF canisters and the DOE SNF 
canisters known as multicanister overpacks (MCOs); 
 DOE canister includes DOE HLW canisters as well as DOE SNF canisters. 
 The term cask is used as an abbreviation for transportation cask to maintain 
consistency with potential event descriptions in Internal Hazards Analysis for License 
Application (BSC 2005 [DIRS 171428]). 
 Monitored geologic repository site-specific casks (MSCs) are referred to as MSCs. 
 Aging cask is a generic term that refers to MSCs and horizontal aging modules 
(HAMs) 
The activities that would be involved in handling commercial multipurpose canisters used by 
utilities, which could conceivably be received at the repository and transferred intact into waste 
packages (WPs) for disposal, are beyond the scope of this analysis because the current design 
does not allow for their use. 
2 QUALITY ASSURANCE 
The Office of Civilian Radioactive Waste Management quality assurance program applies to this 
design analysis because it relates to performance of the preclosure safety analysis.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 22 April 2005 
3 USE OF SOFTWARE 
3.1 SOFTWARE APPROVED FOR QUALITY-AFFECTING WORK 
None used. 
Figure 1. Process Flow for Preclosure Safety Analysis and Postclosure Performance Assessment 
3.2 COMMERCIAL OFF-THE-SHELF SOFTWARE USED 
Microsoft Excel 97 SR-2 was used to calculate results in tables throughout the document. Excel 
is appropriate because standard mathematical expressions and operations available in Excel were 
used to derive the results. The formulas, inputs, and results are presented at the point of use.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 23 April 2005 
4 INPUTS 
4.1 PROJECT DATA 
4.1.1 WP Inventory Information 
The nominal numbers of WPs in various configurations to be emplaced are given in Table 1. 
Table 1. Waste Package Inventory Information 
Waste Package Loadings 
Configuration 
Number 
Waste Package 
Type 
Number of 
Waste 
Packages SNF Unit 
Units per 
Waste 
Package 
Glassc 
Canisters 
per Waste 
Package 
Glassc 
Unit 
1 CSNF (AP) 4,299 PWR 21 0  
2 CSNF (CR) 95 PWR 21 0  
3 CSNF (Long) 163 BWR 12 0  
4 CSNF 2,831 BWR 44 0  
5 CSNF 84 BWR 24 0  
6 Codisposal 1,403 Short Canister 1 5 Short 
7a Codisposal 1,608 Long Canister 1 5 Long 
7b Codisposal 7 None 0 5 Long 
8a Codisposal 192 Wide Canister 1 3 Long 
8b Codisposal 202 MCO 2 2 Long 
9 Naval (Short)a 144 Canister 1 0  
10 Naval (Long) b 156 Canister 1 0  
Total Codisposal Waste Packages 3,412 
Total Commercial and Naval SNF 7,772 
Grand Total 11,184 
NOTES: a Naval (short) is a waste package that contains one short naval canister. 
b Naval (long) is a waste package that contains one long naval canister. 
c Glass is high-level radioactive waste glass. 
BWR = boiling water reactor; CSNF = commercial spent nuclear fuel; AP = absorber plate; CR = control rod; 
PWR = pressurized water reactor; MCO = multi-canister overpack; SNF = spent nuclear fuel. 
SOURCE: BSC 2004 [DIRS 170022], Table 6-3. 
4.1.2 Selected WP Characteristics 
The following dimensions pertain to the Naval Long WP (BSC 2004 [DIRS 169062]):
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 24 April 2005 
 75.8 inches (outside diameter of the outer corrosion barrier) 
 236.3 inches (total length less lid-lifting feature). 
4.1.3 Characteristics of the Ground Support in the Emplacement Drifts 
The recommended ground support in the emplacement drifts consists of 3 m long Super Swellex 
rock bolts, spaced at 1.25 m, and 3 mm thick Bernold-type perforated sheets, made of stainless 
steel and installed in a 240 arc around the drift periphery (BSC 2004 [DIRS 170292], p. 110). 
The rock bolts are made of circular steel tube with a diameter of around 5 cm and a thickness of 
3 mm (BSC 2004 [DIRS 170292], pp. 17 and 83). 
4.1.4 External Hazards 
The analysis Monitored Geologic Repository External Events Hazards Screening Analysis (BSC 
2004 [DIRS 167266], Table 3) found that the following hazards should be considered: aircraft 
crash, rainstorm and flooding, range fire, loss of offsite or onsite power, nearby industrial or 
military activities, seismic activity, tornado and extreme wind, lightning, ash fall due to 
volcanism, drift degradation, extreme weather (temperature) fluctuation, and sandstorm. 
The Industrial/Military Activity-Initiated Accident Screening Analysis found that there are no 
existing or planned military or industrial activities that initiate event sequences with radiological 
consequences during the preclosure period (BSC 2003 [DIRS 162761], Section 8). 
4.1.5 Potential Internal Events 
The categorization analysis is based on the design and operation of the repository as described in 
Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428]). The one-to-one 
correspondence between third-level subsections starting with Section 6.6.1 of Internal Hazards 
Analysis for License Application and Section 6.3.2 of the present analysis will guide the reader 
(Table 2). The lowest-level subsections within Section 6.3 of the present analysis correspond to 
specific potential events that are identified in Internal Hazards Analysis for License Application.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 25 April 2005 
Table 2. Crosswalk to Internal Hazards Analysis 
Functional Area Covered 
Section in This 
Document 
Section in Internal 
Hazards Analysis 
(BSC 2005 [DIRS 
171428]) 
Cask and Waste Package Receipt Building (CWPRB), Transportation 
Cask Buffer Area (TCBA) 
6.3.2 6.6.1 
Canister Handling Facility (CHF) 6.3.3 6.6.2 
Dry Transfer Facility (DTF) 6.3.4 6.6.3 
Fuel Handling Facility (FHF) 6.3.5 6.6.4 
Surface and Subsurface Facilities: WP Subsurface Transport and 
Emplacement 
6.3.6 6.6.5 
Surface Facilities: SNF Aging System 6.3.7 6.6.6 
Subsurface Facilities: Construction Hazards 6.3.8 6.6.7 
Surface Facilities: Construction Hazards 6.3.9 6.6.8 
Subsurface Facilities Drip Shield Installation 6.3.10 6.6.9 
Subsurface Facilities: Retrieval 6.3.11 6.6.10 
Surface Facilities: Site-Generated Radiological Waste Disposal 6.3.12 6.6.11 
4.1.6 Height of Emplacement Drifts and Emplacement Drifts Turnouts 
The diameter of the emplacement drifts is 5.5 m and the height of the emplacement drift turnouts 
is 7 m (BSC 2003 [DIRS 165572], Table 8). 
4.1.7 Number of Emplacement Drifts 
Ninety-six emplacement drifts are needed to contain the waste packages in the repository, based 
on BSC (2003 [DIRS 165572], Table IV-3), which gives the number of drifts in each of the four 
panels that compose the subsurface layout of the repository, and BSC (2003 [DIRS 165572], p. 
59) which indicates that the waste packages will occupy Panels 1, 3, 4, and up to Drift 17 in 
Panel 2. 
4.1.8 Not used 
4.1.9 Fire-Induced Event Sequence Categorization 
The fire-induced event sequences involving a direct exposure of an SNF or HLW waste form to a 
fire, which are identified in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 
171428], Sections 6.6.1 through 6.6.11), are categorized in the Fire-Induced Event Sequence 
Analysis (BSC 2004 [DIRS 171488]). The analysis also categorizes the event sequences 
involving indirect damage fire scenarios. 
The analysis (BSC 2004 [DIRS 171488], Section 7) concludes that even if a precise 
determination of the characteristics of possible fire events in the repository is not possible at this 
stage of the design, the potential for a fire and the severity of the fire relative to the waste form is 
manageable without the need for a fire suppression system.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 26 April 2005 
Controls on the presence and amount of combustibles in the different areas of the repository will 
be implemented through design and operational requirements. This ensures that any Category 1 
or Category 2 event sequence potentially initiated by a fire will be precluded. 
4.1.10 Criticality Safety for CSNF Assemblies 
The analysis Surface Facility Criticality Safety Calculations (BSC 2004 [DIRS 168132], Section 
5.2.3.1) determined that a drop of one or two CSNF assemblies does not pose a criticality safety 
concern. This result ensures that drops, collisions, and other handling impacts of a CSNF 
assembly (allowing for rearrangement of fuel rods and without credit for burnup or moderator 
control) does not pose a criticality safety concern. This input is needed to ensure criticality 
safety in the handling of CSNF assemblies. Credit is not taken for moderator control because 
assembly-handling events can occur in the remediation pool. 
4.1.11 Design Requirements and Categorization Results Related to the SNF Aging System 
A description of system operations, internal hazards, event sequences, and safety strategies 
associated with the SNF Aging System are identified and evaluated in the report SNF Aging 
System Safety Study (Cogema 2004 [DIRS 171793], Section 6). Safety strategies crediting SSCs 
and controls are identified to ensure that there are no Category 1 or Category 2 event sequences 
initiated by external hazards (Cogema 2004 [DIRS 171793], Section 6.3.2). The Cogema study 
develops internal hazard event sequences and safety strategies for vertical and horizontal aging 
systems (Cogema 2004 [DIRS 171793], Tables 6-4 and 6-5). Twenty-three internal event 
sequences for a vertical aging system and twenty-seven internal event sequences for a horizontal 
aging system are developed. All of the internal event sequences for the SNF Aging System are 
determined to be Beyond Category 2 based on implementing specified safety approaches 
(Cogema 2004 [DIRS 171793], Section 6.3.3, including Tables 6-4 and 6-5). The safety 
approaches identified in the SNF Aging System Safety Study are a source of design requirements 
in addition to the design requirements that are generated by the present analysis. 
The SNF Aging System Safety Study does not consider potential event sequences that may occur 
inside process buildings. In addition, potential event sequences that may occur at the interface 
between the SNF Aging System and the other portions of the facility are considered in the 
present analysis as well as in the SNF Aging System Safety Study. The following nuclear safety 
design approaches from SNF Aging System Safety Study (Cogema 2004 [DIRS 171793], Table 6- 
6) are used in the present analysis to address potential event sequences that may occur inside 
process buildings or at the interface with the SNF Aging System: 
 S.12. Ensure aging and transfer casks can withstand a drop from the maximum handling 
height of an MSC transporter or HTC [horizontal transfer cask] trailer without loss of 
function. 
 S.23. Limit size, mass, maximum speed and motive force [of the MSC Transporter and 
HTC Trailer/Tractor] to limit potential damage caused by collisions.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 27 April 2005 
 S.24. Preclude tipover [of the MSC Transporter and HTC Trailer/Tractor] during 
transfer by ensuring that transfer equipment design precludes failure modes that could 
result in tipover under design-basis load-handling conditions. 
 S.25. Preclude tipover during transfer by ensuring minimum tipover resistance/stability 
standards are maintained consistent with roadway design. 
 S.26. Provide reliable means to stop and maintain stability [of the MSC Transporter and 
HTC Trailer/Tractor]. 
4.1.12 Design Requirements and Categorization Results Related to Aircraft Hazards 
An event sequence initiated by an aircraft crash is Beyond Category 2 given the restrictions on 
aircraft operations and the design requirements credited in Frequency Analysis of Aircraft 
Hazards for License Application (BSC 2005 [DIRS 171786], Section 7) are observed. 
4.1.13 Design Requirements and Categorization Results Related to Tornado and Extreme 
Wind 
The Extreme Wind/Tornado/Tornado Missile Hazard Analysis (BSC 2004 [DIRS 171471], 
Section 9) provides design requirements related to tornado and extreme winds. To render event 
sequences involving tornado and extreme wind Beyond Category 2, stationary structures that are 
important to safety (ITS), as well as aging casks, must be designed for tornado missiles, extreme 
straight wind (90 mi/h), and tornado wind (189 mi/h). Tornado missiles and tornado wind are 
screened out for transporters (including WP transporters and transporters used to carry waste to 
and from the aging pads); however, transporters must be designed to function in extreme straight 
wind. 
4.1.14 Design Requirements and Categorization Related to Seismic Events 
Preclosure Seismic Design Methodology for a Geological Repository at Yucca Mountain (BSC 
2004 [DIRS 170564]) outlines the approach that is taken in seismic design of SSCs that are 
important to safety (ITS). The seismic methodology report also outlines the application of 
seismic margins analysis to demonstrate compliance with 10 CFR Part 63 [DIRS 158535], 
including categorization of seismic event sequences. Implementation of design requirements 
from the seismic analysis ensures that surface facilities are designed such that seismic events will 
not initiate Category 1 or Category 2 event sequences that exceed the dose limits in 10 CFR Part 
63 [DIRS 158535]. 
The Seismic Analysis for Preclosure Safety assigns DBGM-1 to the SSCs listed in Table 3 (BSC 
2004 [DIRS 171470], Table IV-1). SSCs designed to withstand a DBGM-1 earthquake are 
presumed to fail if an earthquake that exceeds DBGM-1 occurs. As noted in Section 6.2.6, the 
resulting seismically initiated event sequence is Category 2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 28 April 2005 
Table 3. SSCs Assigned DBGM-1 Seismic Classification 
SSC Safety Function for DBGM-1 Assignment 
Permanent shielding (CHF, DTF, FHF) Shielding integrity remains intact 
Cask pit protective cover (Cask Preparation) Shielding integrity remains intact 
WP pit protective cover (WP Preparation) No failure 
MSC pit protective cover (WP Preparation) No failure 
HLW canister No breach 
WP transporter Shielding integrity remains intact 
Fuel Handling Machine and grapples (Wet Remediation) Maintain waste form 
Spent Fuel Transfer Machine and grapples (Dry Transfer) Maintain waste form 
Inlet and outlet dampers and ducting for fuel element 
staging areas (DTF only, Surface Industrial Heating 
Ventilation, and Air-Conditioning (HVAC), required for 
passive airflow). 
No failure 
Stack for fuel element staging areas (DTF only, Surface 
Industrial HVAC, required for passive airflow) 
Controlled failure (potential for seismic 
interaction) 
HEPA filters (Primary Surface Nuclear HVAC) No discharge 
Exhaust ducting and dampers (Primary Surface Nuclear 
HVAC) 
No discharge 
SOURCE: BSC 2004 [DIRS 171470], Table IV-1. 
4.1.15 Requirements Related to Range Fire 
Range fire has been identified as a potential external hazard. The Wildfire Exposure Calculation 
(BSC 2004 [DIRS 168205], Section 7) concluded that the required minimum separation distance 
between structures containing radiological material and combustible vegetation is 33 feet and 
complies with applicable fire protection codes and standards for protection of structures from 
wildfire exposure and hazards (BSC 2004 [DIRS 168205], Section 7). 
4.1.16 Characteristics of the Drip Shield and Its Emplacement Gantry 
The drip shield and its emplacement gantry are designed to straddle the waste package during 
installation (BSC 2004 [DIRS 168381]). 
4.1.17 Design Requirements and Categorization Related to Waste Package Transporter 
Runaway 
The Waste Package Transporter Preclosure Safety Analysis (BSC 2004 [DIRS 169554]) 
analyzes the probability of a transporter runaway event sequence. Two scenarios of uncontrolled 
descent are analyzed (BSC 2004 [DIRS 169554], Section 6.5). The first scenario involves a 
failure to stop or slow the WP transporter given that some undefined initiating event has 
attempted to accelerate the transporter or allowed it to exceed its maximum allowable speed. 
The second scenario assumes 1) a coupler failure between the locomotive and the WP transporter 
car; 2) the WP transporter car is located ahead of the locomotive on the downgrade; and 3) the 
automatic brake system on the transporter fails to stop or retard the now decoupled railcar. 
Based on BSC (2004 [DIRS 169554], Section 6.5), operator-induced runaways can be eliminated 
from further consideration, and only a failure of components of the service and regenerative
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 29 April 2005 
brake systems can initiate an uncontrolled descent. Thus, the two scenarios mentioned 
previously are the only ones relevant for analyzing the transporter runaway event sequences. 
The results of the analysis (BSC 2004 [DIRS 169554], Sections 6.4 and 6.10) show that because 
of design features, involving principally the use of diversified braking systems, the probability of 
the scenarios for a transporter runaway can meet the reliability goal that makes the transporter 
runaway Beyond Category 2. The numerical value of this reliability goal was determined to be 
8.3  10-9 runaway per trip (BSC 2004 [DIRS 169554], Section 6.4). 
4.1.18 Characteristics of DOE SNF Canisters 
DOE SNF may arrive at the repository in a standardized canister or an MCO. The term DOE 
SNF canisters includes standardized and MCO canisters. 
 DOE SNF standardized canisters can withstand, without breaching, a drop in any 
orientation from a height of 23 ft (7 m) onto an essentially unyielding flat surface (BSC 
2004 [DIRS 168792], Section 6). 
 MCO canisters can withstand, without breaching, a flat-bottom drop (3 degrees or less 
off vertical) from a height of 23 ft (7 m) and a drop in any orientation from a height of 2 
ft (0.6 m) (individuallynot both in sequence) onto an essentially unyielding flat surface 
(BSC 2004 [DIRS 168792], Section 6). 
 The probability that a DOE SNF canister, whether MCO or standardized, is defective 
such that it may breach if dropped from within the height limits stated above is 
conservatively estimated as 2.3  10-4 (BSC 2004 [DIRS 168792], Section 6). 
4.2 INPUTS FROM EXTERNAL SOURCES 
4.2.1 Characteristics of Transportation Casks 
Transportation casks with impact limiters must be evaluated under normal conditions of transport 
which include high and low ambient temperatures and insolation (10 CFR 71.71 [DIRS 
171308]). 
Hypothetical accident conditions under which transportation casks must be evaluated include 
exposure of the specimen fully engulfed, except for a simple support system, in a hydrocarbon 
fuel/air fire of sufficient extent, and in sufficiently quiescent ambient conditions, to provide an 
average emissivity coefficient of at least 0.9, with an average flame temperature of at least 800C 
(1475F) for a period of 30 minutes, or other thermal test that provides the equivalent total heat 
input to the package and which provides a time-averaged environmental temperature of 800C 
(10 CFR 71.73 [DIRS 171308]). 
Transportation casks with impact limiters are required to withstand (without breach) a 9-m 
(30-ft) drop onto a flat, essentially unyielding, horizontal surface, striking the surface in a 
position for which maximum damage is expected and a 1-m (40-in) drop onto a vertical 15-cm 
(6-in) diameter mild steel bar in a position for which maximum damage is expected (10 CFR 
71.73 [DIRS 171308]).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 30 April 2005 
Material within transportation casks must be subcritical under the hypothetical accident 
conditions in 10 CFR 71.73 [DIRS 171308] even with the most reactive credible configuration of 
the fissile material and moderation by water to the most reactive credible extent (10 CFR 71.55 
[DIRS 171308]). 
4.3 CRITERIA 
The categorization analysis takes credit for criteria from existing requirements documents. This 
section identifies those existing requirements. 
4.3.1 Repository Capacity 
The capacity of the repository is 70,000 metric tons of heavy metal (MTHM), including 63,000 
MTHM of CSNF and 7,000 MTHM of DOE SNF, HLW, and naval SNF. This is a requirement 
from the Project Requirements Document (Canori and Leitner 2003 [DIRS 166275], 
PRD-014/T-001 p. 3-95). 
4.3.2 Precipitation and Flooding 
Facilities that could be damaged by flooding shall be located above the probable maximum flood 
elevation or appropriately protected from flood (BSC 2004 [DIRS 171599], Section 6.1.2.1) and 
the repository shall be designed to withstand and operate in the precipitation environment 
described in Table 4 (BSC 2004 [DIRS 171599], Section 6.1.1.1.2). Site drainage shall protect 
the ramp, ramp portal, shaft, and shaft collar areas from water inflow as a result of the probable 
maximum flood (BSC 2004 [DIRS 171599], Section 4.2.1.2.6). Site drainage shall contain and 
route stormwater from natural surface water drainage ways around surface facilities and provide 
water drainage for systems located on pads (BSC 2004 [DIRS 171599], Section 4.2.1.2.6). Site 
drainage shall be designed for the runoff accumulated from the storms identified in Table 4 (BSC 
2004 [DIRS 171599], Section 4.2.1.2.6) 
These criteria are used in Section 6.2.2. 
Table 4. Precipitation Environment 
Parameter and Frequency Nominal Value 
Upper Bound 
90-percent Confidence Value 
Maximum Annual Precipitation 20 in/y NA 
Maximum 24-h Precipitation (50-y 
return period) 
2.79 in/day 3.30 in/day 
Maximum 24-h Precipitation (100-y 
return period) 
3.23 in/day 3.84 in/day 
Maximum 24-h Precipitation (500-y 
return period) 
4.37 in/day 5.25 in/day 
Maximum 1-h Precipitation Intensity 
(50-y return period) 
1.35 in/h 1.72 in/h 
Maximum 1-h Precipitation Intensity 
(100-y return period) 
1.68 in/h 2.15 in/h 
SOURCE: BSC 2004 [DIRS 171599], Section 6.1.1.1.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 31 April 2005 
4.3.3 Emplacement and Retrieval System 
The system shall be able to determine equipment location in an emplacement drift (BSC 2004 
[DIRS 171251], Section 3.1.2.2.1). 
The system shall have the capability to identify the drift and location within the drift where the 
WP will be emplaced (BSC 2004 [DIRS 171251], Section 3.1.1.3.1). 
4.3.4 Lightning 
The Project Design Criteria Document (BSC 2004 [DIRS 171599], Section 4.3.1.5) specifies the 
approach for protection against lightning as follows: 
 All buildings, outdoor elevated structures, electrical equipment, and electrical power 
lines shall be protected with lightning arresters and surge capacitors. 
 The lightning protection system shall be installed for all buildings and outdoor elevated 
structures. The protection system shall consist of air terminals bussed together and 
connected by at least two down conductors to the site grounding system. 
4.3.5 Not used 
4.3.6 Gas Sampling and Purging 
 The inside of the cask shall be sampled for elevated pressure and for gases that may 
indicate a hazardous condition, such as fission products and/or flammable or explosive 
gas mixtures. (Curry 2004 [DIRS 170557], Requirement 1.1.2.1.1-4). 
 The transportation cask shall be vented to atmospheric pressure. If combustible gases 
are present in the sample, the transportation cask must be purged until samples show a 
level below LEL [lower explosive limit]. (Curry 2004 [DIRS 170557], Requirement 
1.1.2.1.1-5). 
 The inside of the DPC shall be sampled for gases that may indicate hazardous 
conditions, such as flammable or explosive gas mixtures and fission products. (Curry 
2004 [DIRS 170557], Requirement 1.1.2.1.4-2). 
 The DPC shall be vented to achieve atmospheric pressure. If combustible gases are 
present in the sample, the DPC must be purged until samples show a level below LEL. 
(Curry 2004 [DIRS 170557], Requirement 1.1.2.1.4-3). 
 The MGR shall be capable of venting, purging, and opening sealed WPs, as required. 
(Curry 2004 [DIRS 170557], Requirement 1.1.4.1-6).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 32 April 2005 
5 ASSUMPTIONS 
5.1 ASSUMPTIONS THAT GENERATE REQUIREMENTS 
Many of the assumptions that are used to categorize event sequences invoke design requirements 
or operational requirements that are not found in existing requirements documents. This means 
that the function of the assumptions in this section is not simply to provide reasonable values for 
inputs that are not yet established or are difficult to determine. Instead, their function is to 
identify features of the design that are directly relied upon to make the case for preclosure safety. 
The rationale in every case is that the proposed design requirement is believed to be reasonable 
and achievable. The subsequent nuclear safety design basis report will formalize the 
requirements identified in this section. If further evolution of the design reveals that some of the 
requirements are not achievable, or that the same safety goal could be achieved at less cost by 
implementing a different design requirement, then a different assumption may be made in a 
revision of this document and the design requirement may be changed. This iterative process is 
described in Section 1 and illustrated in Figure 1. 
5.1.1 General Assumptions 
5.1.1.1 Maximum Receipt Rate of CSNF Assemblies 
Assumption: The receipt rate for CSNF in any year may not exceed 3,600 MTHM. Rationale: 
This annual receipt rate is 12 times the monthly requirement to be able to receive, handle, and 
emplace 300 metric tons of uranium equivalent (or, what amounts to the same thing for CSNF, 
300 MTHM) monthly in the Yucca Mountain Site Characterization Project Requirements 
Document (YMP 2001 [DIRS 156713], Requirement 1.3.2E). This rate conservatively allows 
for a 20 percent margin above the 3,000 MTHM requirement for annual receipt capability given 
by the Civilian Radioactive Waste Management System Requirements Document (DOE 2004 
[DIRS 171945], Table 1). 
5.1.1.2 Criticality Safety for Canister Staging Pits or Racks 
Assumption: A design requirement will ensure that the most reactive configuration of 
standardized DOE SNF canisters can be loaded into canister staging pits or racks (with credit for 
moderator control as described in Assumption 5.1.1.21) without causing a nuclear criticality. 
Rationale: This assumption is needed to ensure criticality safety in case of handling incidents. 
It is reasonable to expect that design calculations will demonstrate criticality safety. 
5.1.1.3 Criticality Safety for DOE SNF Canisters (Given a Drop) 
Assumption: Design calculations and the resulting design requirements will ensure that a drop 
of a DOE SNF canister will not lead to a nuclear criticality. The calculations will assume that 
the canister is not breached. The calculations for the staging rack will demonstrate criticality 
safety with the most reactive configuration of DOE SNF canisters and moderator control as 
described in Assumption 5.1.1.21. Rationale: This assumption is needed to ensure criticality 
safety in case of handling incidents. The requirement is achievable because moderator control is 
required in waste handling areas (BSC 2004 [DIRS 171599], Section 4.9.2.2.3).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 33 April 2005 
5.1.1.4 Criticality Safety for MSCs, Transportation Casks, Transfer Casks, CSNF 
Baskets, and DPCs (Given a Drop) 
Assumption: Design requirements and waste acceptance criteria will ensure that transportation 
casks, transfer casks, MSCs, CSNF baskets used in dry processing areas, and dual-purpose 
canisters (DPCs) will be designed to ensure nuclear criticality safety with optimum moderation 
and most reactive waste forms. Criticality safety will be maintained despite geometric 
rearrangements due to a drop or other handling incident. Rationale: The purpose of this 
assumption is to reduce reliance on administrative controls to prevent preclosure criticality. 
Drop scenarios without impact limiters are not covered by the accident scenario analyses that are 
performed to support licensing of a transportation cask under 10 CFR Part 71 [DIRS 171308]. 
To cover drops without impact limiters, subsequent calculations are needed to demonstrate 
subcriticality for the most reactive credible configuration of the fissile material in transportation 
casks, transfer casks, and MSCs and moderation to the most reactive credible extent. 
5.1.1.5 Pressurized-System Missiles 
Assumption: An operational requirement will ensure that pressurized systems that could 
generate missiles energetic enough to penetrate a transportation cask with or without impact 
limiters, a transfer cask, a DOE canister, a naval canister, a DPC, the inner lid of a transportation 
cask, an MSC, a WP, or the inner lid of an MSC or WP are not present in areas where the 
potentially vulnerable items may be exposed. Rationale: This assumption ensures that the event 
sequences involving a pressurized system missile that breaches a container are Beyond Category 
2. The requirement is achievable because the handling process does not require the use of highpressure 
devices that have the potential to cause a breach. Moreover, the containers are robust 
structures that would withstand the effects of the failure of pressure vessels like those that may 
be present on vehicles and cranes. 
5.1.1.6 Limitations on Combustible Materials Near Low-Level Radioactive Waste 
Assumption: Operational requirements will provide a control program ensuring that any fire 
that may occur in areas where low level radioactive waste (LLW) forms are stored will not be of 
intensity, duration, or magnitude to initiate an event sequence. Rationale: This is achievable by 
ensuring adequate isolation and confinement of LLW from combustible sources and materials. 
5.1.1.7 Drop Rate for the Spent Fuel Transfer Machine and Fuel Handling Machine 
Assumption: Design and operational requirements will ensure that the drop rate for the spent 
fuel transfer machine (in the dry transfer areas) and fuel handling machine (in the pool), 
including transfers in single-assembly canisters, is less than or equal to 10-5 drops/transfer. 
Rationale: The drop rate required is achievable because it is comparable to the historical drop 
rate derived below from fuel-handling incidents in commercial nuclear reactors in the period 
from 1985 through 1999 (BSC 2001 [DIRS 157560], Section 5.2). Handling incidents are 
included regardless of cause; they may be caused by equipment failures, human error, or some 
combination of the two. The starting year for the range was chosen because incident-reporting 
practices were inconsistent before 1985 and because rules and regulations precipitated by the 
Three Mile Island accident were in place by that time (Framatome ANP 2001 [DIRS 156397],
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 34 April 2005 
p. 2). The end year, 1999, was the latest year for which the information was available at the time 
of the study (Framatome ANP 2001 [DIRS 156397], p. 2). Of the 91 fuel-handling events listed 
(BSC 2001 [DIRS 157560], Table I-1), nine involved fuel-assembly drops and are applicable to 
the repository (Event Numbers 4, 8, 29, 32, 34, 71, 80, 83, and 86). The number of fuel transfers 
over the period of observation was estimated to be 1,199,000 (BSC 2001 [DIRS 157560], 
Assumption 3.1). Thus, the computed frequency of drops per transfer is 9/1,199,000 = 7.5  10-6 
drops/transfer, which is rounded up to 10-5 drops/transfer. Calculations that use the assumed 
drop rate include contributions from equipment failure and human error. 
5.1.1.8 Collision Rate for Individual CSNF Assembly Transfers 
Assumption: Design and operational requirements will ensure that the rate of collisions during 
an assembly-transfer operation is less than or equal to 10-5 collisions/transfer. Rationale: The 
collision rate required is based on fuel-handling incidents in commercial nuclear reactors in the 
period from 1985 through 1999 (BSC 2001 [DIRS 157560], Section 5.2). Handling incidents are 
included regardless of cause; they may be caused by equipment failures, human error, or some 
combination of the two. The starting year for the range was chosen because incident-reporting 
practices were inconsistent before 1985 and because rules and regulations precipitated by the 
Three Mile Island accident were in place by that time (Framatome ANP 2001 [DIRS 156397], 
p. 2). The end year, 1999, was the latest year for which the information was available at the time 
of the study (Framatome ANP 2001 [DIRS 156397], p. 2). Of the 91 fuel-handling events listed 
(BSC 2001 [DIRS 157560], Table I-1), eight involved fuel-element collisions that damaged fuel 
assemblies and are applicable to the repository (Event Numbers 16, 24, 40, 56, 63, 68, 70, and 
89). The number of fuel transfers over the period of observation was estimated to be 1,199,000 
(BSC 2001 [DIRS 157560], Assumption 3.1). Thus, the computed frequency of collisions per 
transfer is 8/1,199,000 = 6.7  10-6 collisions/transfer, which is rounded up to 10-5 
collisions/transfer. Calculations that use the assumed collision rate include contributions from 
equipment failure and human error. 
5.1.1.9 Rate of Handling-Equipment Drop or Collision Involving the Spent Fuel 
Transfer Machine and Fuel Handling Machine 
Assumption: Design and operational requirements will ensure that the probability of dropping 
handling equipment onto a CSNF assembly energetically enough to breach the assembly is 10-7 
impacts per transfer or less for each assembly transferred. The requirement applies to the spent 
fuel transfer machine (in the dry transfer areas) and fuel handling machine (in the pool), which 
are used to transfer CSNF assemblies one at a time. Because adjacent assemblies are included, 
and because the amount of time the equipment is suspended above an assembly may vary, the 
probability depends on the sequence of steps that are used to accomplish the transfer as well as 
the characteristics of the handling device. Rationale: This assumption is needed to ensure that 
the associated unlikely events, which appear to have little potential to initiate an event sequence, 
are not Category 1. The requirements are achievable because the absence of a load decreases the 
likelihood of failure due to mechanical stress and because operational controls can prevent 
suspension of handling equipment above assemblies except as required for operational purposes.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 35 April 2005 
5.1.1.10 Load Drop Rate for Cranes 
Assumption: Design and operational requirements will ensure that the drop rate for cranes 
involved in handling waste forms and their associated containers is less than or equal to 10-5 
drops/transfer. Handling incidents that result in a drop are included in the required drop rate 
regardless of cause; they may be caused by equipment failures (including failures in the yokes 
and grapples), human error, or some combination of the two. Rationale: This reliability is 
considered achievable based on an evaluation of nuclear power plant heavy lift crane reliability 
performed by the U. S. Nuclear Regulatory Commission (Collins and Hubbard 2001 [DIRS 
156981]). The U. S. Nuclear Regulatory Commission determined that a mean crane drop 
frequency of 9.6  10-6 drops per year assuming 100 transfers per year (that is, a drop rate of 
9.6  10-8 per transfer) can be achieved by single-failure-proof cranes or cranes conforming to 
specified guidelines (Collins and Hubbard 2001 [DIRS 156981], p. 3-17). The assessment was 
performed for cranes that handle CSNF storage casks. Since the repository will have training for 
crane operators and maintenance programs similar to nuclear fuel handling facilities, it is 
reasonable to expect that cranes used in the repository can be designed with a drop rate of 10-5 
drops per transfer or less. 
5.1.1.11 Rate for Handling-Equipment Drops from Cranes for Canister Transfers 
Assumption: Design and operational requirements will ensure that the probability of dropping 
handling equipment from a crane onto a canister is 10-5 or less for each canister transferred. 
Failures are included regardless of cause; they may be caused by equipment failure, human error, 
or some combination of the two. Rationale: This assumption is needed to drive breaches due to 
equipment drop to Beyond Category 2 for DOE SNF canisters and to Category 2 for other 
canisters. The dropped equipment is most likely to strike the canister targeted for transfer, either 
just before the transfer or just after. Because a drop may affect a canister adjacent to the one 
targeted for handling and because the amount of time the equipment is suspended above a 
canister may vary, the probability depends on the sequence of steps that are used to accomplish 
the transfer as well as the characteristics of the crane. The probability of dropping handling 
equipment onto a canister other than the one targeted for transfer is less because the equipment 
would not be suspended above other canisters for long. If a different canister is struck, chances 
are it will be of the same type as the target canister because canisters of the same type are 
shipped together (Assumption 5.2.1.13) and because equipment-suspension time over canisters 
of a different type in a WP or staging rack is small compared to the suspension time over the 
target canister or canisters of the same type as the targeted canister. Therefore, the possibility of 
equipment drop onto a canister of a different type from the target canister is neglected in the 
categorization analysis. The requirements are achievable because the absence of a load 
decreases the likelihood of crane failure due to mechanical stress and because operational 
controls can prevent suspension of handling equipment above canisters except as required for 
operational purposes. 
5.1.1.12 Probability of Exceeding the Lift-Height Limits for Cranes 
Assumption: Design and operational requirements for cranes will ensure that the conditional 
probability of having exceeded the lift-height limit, given that a drop occurred, is 10-4 or less. 
Rationale: Wherever lift-height limits are credited in the analysis, this assumption is needed to
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 36 April 2005 
calculate the number of drops from above the lift-height requirement. Stating the design 
requirement in this way allows for the possibility that lifting the load above the drop-height limit 
and dropping the load are not statistically independent. Depending on design solutions, other 
conditions may be required to ensure that a drop and a breach are Beyond Category 2. For 
example, casks containing MCOs may require special treatment, such as placement of portable 
impact limiters, the failure of which could contribute to the conditional probability of a breach 
given a drop. Because specific design and operational solutions are not yet established, this 
assumption is limited to consideration of lift-height limits. The requirement is achievable 
because passive safety features on the crane and, if applicable, procedural controls can be used to 
drive the conditional probability into the required range. 
5.1.1.13 Limitations on Heavy Doors 
Assumption: A design requirement will ensure that closure of airlock doors, shield doors, and 
other applicable doors onto a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, or 
WP transporter, would not cause a tipover of the conveyance or cause the conveyance to drop its 
load. A design requirement will ensure that closure of airlock doors, shield doors, and other 
applicable doors onto a transportation cask, transfer cask, or MSC suspended from an overhead 
crane will not cause the crane to drop its load. Rationale: This assumption is needed to 
dispense with identified events that may occur to initiate Category 1 or Category 2 event 
sequences. The requirement is achievable because there is no operational need for rapid closure 
of doors; in fact, rapidly closing doors would compromise operational safety. 
5.1.1.14 Lift-Height Limits for Standardized DOE SNF Canisters 
Assumption: A design requirement will limit lift heights for standardized DOE SNF canisters to 
less than the most limiting height as follows: 
 23 ft (7 m) above the floor of a cask, WP, staging rack, or staging pit (implies 
approximately vertical orientation) 
 2 ft (0.6 m) above the floor of the transfer cell (any orientation). 
Rationale: The 23-ft limit is based on the structural capabilities of standardized DOE SNF 
canisters (Section 4.1.18). The 2-ft limit is not required to prevent breach of the standardized 
canister when dropped in any orientation (as on the floor of the transfer cell where vertical 
orientation is not guaranteed), but is set to 2 ft for consistency with the structural capabilities of 
the MCO (Section 4.1.18). The requirement is achievable because design features can limit lift 
heights. 
5.1.1.15 Lift-Height Limits for MCOs 
Assumption: Design requirements will limit lifts of MCO canisters to less than the most 
limiting height as follows: 
 2 ft (0.6 m) above the floor of the transfer cell (any orientation) 
 23 ft (7 m) above the floor of a cask or WP (within 3 degrees of vertical orientation).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 37 April 2005 
For the drops onto the floor of a cask or WP, design requirements will restrict the size of the 
berth in casks and WPs such that the canister cannot be tilted more than 3 degrees from vertical 
upon impact with the floor of the berth. 
Rationale: The assumption is needed to ensure that breach of MCO canisters is Beyond 
Category 2. The proposed design requirements are based on the structural capabilities of MCOs 
(Section 4.1.18). 
5.1.1.16 Premature Movement of Turntable will Not Breach the WP 
Assumption: A design requirement will preclude premature actuation of the turntable (holding 
the WP on an emplacement pallet) before the disengagement of the trunnion collar removal 
machine. Rationale: This assumption is needed to dispense with an identified event that may 
occur but has little potential to initiate an event sequence. The requirement is achievable because 
the system could be designed to stop attempted movement if excessive resistance is encountered. 
5.1.1.17 Drop or Collision of Components Associated with a Docking Port 
Assumption: A design requirement will ensure that a drop of or collision involving components 
associated with a docking port will not breach the lid of a cask or MSC situated at the docking 
port. Rationale: This assumption is needed to dispense with a potential event that may occur 
but has little potential to initiate an event sequence. 
5.1.1.18 Lift-Height Limits for Transportation or Transfer Casks Without Impact 
Limiters and MSCs 
Assumption: Design requirements limit the lift heights above an essentially unyielding surface 
for transportation casks without impact limiters, transfer casks without impact limiters, and 
MSCs as follows: 
 For casks that contain MCOs 
 When credit is not taken for impact absorption by structural features other than the 
MCO canisters, lift height is limited to 2 ft (0.6 m) in any orientation above an 
essentially unyielding surface. 
 When credit is taken for impact absorption by structural features other than the MCO 
canisters, lift height is limited to the maximum height from which the cask can be 
dropped without breaching the canister. 
 For naval casks, lift height is limited to 16 ft (5 m) or less in any orientation above an 
essentially unyielding surface. 
 For other casks, lift height is limited to 23 ft (7 m) or less in any orientation above an 
essentially unyielding surface. 
These heights may be exceeded where impact absorption by crush pads or other features is 
credited. The crush pads shall limit the impact energy for a dropped cask to be less than or equal
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 38 April 2005 
to the impact energy associated with a cask dropped onto an unyielding surface from the 
maximum specified drop height for the cask. For casks that contain canisters, the cask and the 
basket structure within the cask must prevent stresses on the canisters in excess of the stresses 
imposed by a drop of a canister alone. 
Rationale: The assumption is needed to render breach of DOE SNF canisters Beyond Category 
2 and to conform with event descriptions provided to the U.S. Navy (Cogema 2004 [DIRS 
169064], Section 1.3). As stated in Section 4.1.18, standardized DOE SNF canisters can 
withstand without breach a 23-ft (7-m) drop in any orientation. Assuming that the cask and the 
basket structure within the cask prevent additional stresses on the canisters within, canisters 
inside a cask will withstand a cask drop from the same height. This is the basis for the 23-ft limit 
for casks that do not contain MCOs or naval SNF. The 2-ft requirement for casks that contain 
MCOs is based on the fact that MCOs can withstand a 2-ft drop in any orientation without 
breach (Section 4.1.18). The 2-ft requirement is achievable because various means are available, 
such as movable crush pads, recessed railbeds, and crush pads inside the MCO casks, to limit 
energy transmitted to the MCO in case of a drop. The 16-ft requirement for naval casks is 
achievable because 16 ft provides ample room for the required lifts (Cogema 2004 [DIRS 
169064], Section 1.3). Limiting lift height allows appropriate source terms to be chosen for the 
consequence analysis. Crane features and controls for handling transportation casks and MSCs 
(such as limit switches) can also be utilized to ensure that allowable lift heights will not be 
exceeded. For CSNF casks and for HLW casks, the 23-ft limit is used, consistent with the limit 
for casks that contain standardized DOE SNF canisters. Limiting lift height allows appropriate 
source terms to be chosen for the consequence analysis. Wherever crush pads are credited, 
analyses will confirm that the impact consequences associated with a drop of a cask onto energy 
absorbing crush pads are equal to or less than the impact consequences associated with the drop 
of a cask from the maximum specified drop height onto an unyielding surface. 
5.1.1.19 Prevention of Crane Collisions at Speeds that Could Cause Breach 
Assumption: A design requirement will limit speeds for crane transfers such that a collision at 
the maximum speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE 
canister, naval canister, or waste package involved in the transfer. Rationale: Design 
calculations will establish maximum speeds for crane transfers and design features will ensure 
that the maximum speeds are not exceeded. 
5.1.1.20 Force Limits for Lateral Crane Movements 
Assumption: A design requirement will ensure that cranes are not capable of exerting sufficient 
force during a transfer to breach a transportation cask, transfer cask, MSC, WP, or canister as the 
result of attempts to overcome mechanical constraints. Rationale: Design calculations will 
establish maximum lateral force limits for crane transfers. The requirement is achievable 
because the containers are robust and can withstand considerable stress without breach and 
because limited lateral forces are required to achieve the required crane movements.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 39 April 2005 
5.1.1.21 Control of Potential Moderators 
Assumption: Design and operational requirements will ensure that materials such as water, 
water mist, hydrogenous foam, and other hydrogenous materials that could serve as a moderator, 
are strictly controlled in dry-transfer areas in the Dry Transfer Facility (DTF), Canister Handling 
Facility (CHF), and Fuel Handling Facility (FHF) and wherever loaded unsealed WPs may be 
present. A design requirement will ensure that flooding of areas of the facilities where 
moderators are controlled is precluded by passive design features such as drains, flood control 
channels, curbs, elevated processing areas, and walls. In particular, there must be appropriately 
sized flood-control features between pipes carrying water (or other moderators) and moderator 
control areas. Although small quantities of water may be used in the closure cells for stress 
mitigation, and small quantities of other moderators, such as crane lubricating oil, may be 
present in other affected areas, the proposed design and operational requirements must limit the 
accumulation of liquid moderator in areas that contain fissile material to prevent criticality. 
Rationale: The requirements are part of the criticality-prevention strategy. Criticality control 
will be implemented through passive controls including moderator control, geometry, and fixed 
neutron absorbers. Because criticality analyses assume that moderator may be present when 
evaluating the effects of geometry and neutron absorbers, taking credit for moderator control 
means that other features that prevent criticality, such as geometry and neutron absorbers, may 
be treated as defense in depth. For moderators that are intentionally introduced into moderatorcontrol 
areas, criticality calculations will specify limits on the amounts permitted wherever such 
limits are required for criticality safety. Flood control is also required for operational reasons. 
5.1.1.22 DOE SNF Canisters Survive Lid Drops 
Assumption: Operational requirements will limit the lift height of the inner lid of a 
transportation cask, transfer cask, MSC, or WP to ensure that a lid drop onto a DOE SNF 
canister within that breaches the canister is a Beyond Category 2 event sequence. Rationale: 
The requirements are achievable because mechanical clearance for transferring the lid will 
require lifting the lid only a modest distance above the top of the canister. In addition, the basket 
structure within the WP or cask may be credited to absorb some of the impact energy. 
5.1.1.23 DOE SNF Canisters Transferred Before HLW Canisters 
Assumption: Operational controls will render dropping a DOE SNF canister onto a DOE HLW 
canister Beyond Category 2. In particular, 
 DOE SNF canisters are not transferred into a WP or MSC if one or more HLW canisters 
are already present in the same WP or MSC. 
 DOE SNF canisters are not removed from a WP or MSC if one or more HLW canisters 
are still present in the same WP or MSC. 
Rationale: This assumption is required to ensure that DOE SNF canisters are not dropped onto 
the narrow neck of the HLW canisters. The requirement is achievable because it results in 
simple rules for determining the handling order for DOE canisters and verifiable intermediate 
steps.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 40 April 2005 
5.1.1.24 Lift-Height Limit for HLW Canisters 
Assumption: A design requirement will limit lift heights for HLW canisters to less than 23 ft (7 
m) above the floor of a cask, WP, staging rack, or staging pit and 2 ft (0.6 m) above the floor of 
the transfer cell. Rationale: This assumption is needed to ensure that the drop of a DOE HLW 
canister onto a DOE SNF canister does not cause a Category 1 or Category 2 breach of the DOE 
SNF canister. In addition, the lift-height limits allow an appropriate source term to be chosen for 
releases due to breached HLW canisters. The distances above the cell floor and floors of 
containers provide an implied maximum lift height above a DOE SNF canister inside a cask, 
WP, staging rack, or staging pit. The requirement is achievable because design features can limit 
lift heights. 
5.1.1.25 DOE SNF Canisters Withstand Impact from Dropped HLW Canister 
Assumption: A design requirement will ensure that a DOE SNF canister in a cask, WP, staging 
rack, or staging pit will withstand without breach the drop of a DOE HLW canister onto the top 
of the DOE SNF canister from within the following heights: 
 23 ft (7 m) above the floor of the cask, WP, staging rack, or staging pit 
 2 ft (0.6 m) above the floor of the transfer cell. 
Rationale: This assumption is required to prevent breach of a DOE SNF canister if a DOE 
HLW canister is dropped onto a DOE SNF canister that is not defective. It is based on the lift 
height limits given in Assumption 5.1.1.24. 
5.1.1.26 Prevention of a Drop of a CSNF Assembly into a WP or MSC Loaded with 
DOE Canisters 
Assumption: An operational requirement will render drop of a CSNF assembly into a WP or 
MSC loaded with DOE canisters Beyond Category 2. Rationale: This assumption is required to 
implement the approach that breach of DOE SNF canisters is a Beyond Category 2 event. It is 
achievable because the implementing procedures could be designed to provide the required 
reliability. 
5.1.1.27 Prevention of Drop of a DOE Canister into a WP or MSC Loaded with CSNF 
Assemblies 
Assumption: An operational requirement will render drops of DOE canisters into a WP or MSC 
loaded with CSNF assemblies Beyond Category 2. Rationale: This assumption is required to 
implement an approach that breach of a DOE SNF canister is Beyond Category 2. It is 
achievable because the implementing procedures could be designed to provide the required 
reliability. 
5.1.1.28 DOE SNF Canisters Dropped on Other DOE SNF Canisters 
Assumption: A design requirement is assumed to ensure that standardized DOE SNF canisters 
will withstand without breach a drop of another standardized DOE SNF canister and that MCOs
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 41 April 2005 
will withstand without breach a drop of another MCO dropped from within the most limiting 
height as follows: 
 23 ft (7 m) above the floor of a cask, WP, staging rack, or staging pit (as applicable). 
 2 ft (0.6 m) above the floor of the transfer cell. 
Rationale: This assumption is required to prevent breach of a standardized DOE SNF canister 
or MCO that is not defective. The requirement is achievable because DOE SNF canisters are 
designed to withstand more challenging impacts without breach. That is, the impacts described 
in Section 4.1.18 assume a drop onto an essentially unyielding surface from a maximum height 
of 23 ft, whereas for the drops under consideration here, 
 Impact energy would be absorbed by the canister already in place. 
 The drop height of one canister upon another is at most 23 ft minus the length of the 
canister already in place. 
5.1.1.29 DOE SNF Canisters Dropped onto a Structural Corner 
Assumption: A design requirement will ensure that a standardized DOE SNF canister or MCO 
(as applicable) will not breach if dropped onto the edge of a WP, staging-pit or load-port edge, or 
WP internal baffle from the most limiting height as follows: 
 23 ft (7 m) above the floor of the cask, WP, staging rack, or staging pit (for standardized 
canisters) 
 23 ft (7 m) above the floor of the cask or WP (for MCOs) 
 2 ft (0.6 m) above the floor of the transfer cell (for standardized and MCO canisters). 
Rationale: This assumption is required to prevent breaches of DOE SNF canisters that are not 
defective. It is based on the lift height limits given in Assumptions 5.1.1.14 and 5.1.1.15. The 
requirement is achievable because DOE SNF canisters are robust and only modest lifts of DOE 
SNF canisters are required for operational purposes. 
5.1.1.30 Use of Equipment Over or Near Casks or MSCs 
Assumption: Operational requirements for cask preparation and handling will ensure that a 
drop of or collision involving equipment would not breach a transportation cask, transfer cask, or 
an MSC. Rationale: The requirements may establish maximum lift heights or travel speeds and 
will affect operations only. This assumption is needed to dispense with potential events with 
little potential to initiate an event sequence. The requirements are achievable because 
transportation casks and MSCs are rugged containers and lifts of equipment high above the cask 
and rapid travel speeds are not needed for operational reasons.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 42 April 2005 
5.1.1.31 Handling Equipment Drops from Limited Height Incapable of Breaching a 
DOE SNF Canister 
Assumption: An operational requirement will ensure the establishment of a maximum lift 
height limit for handling equipment suspended above DOE SNF canisters. The lift-height limit 
will be set to the minimum required for operational purposes. A design requirement will ensure 
that the handling equipment is not capable of causing an event sequence due to a breach of a 
DOE SNF canister if dropped from within the lift-height limit. Rationale: This assumption is 
needed to ensure that breach of DOE SNF canisters is Beyond Category 2. The requirements are 
achievable because DOE SNF canisters are rugged containers and lifts of the handling equipment 
high above the canister are not needed for operational reasons. 
5.1.1.32 Drop of Miscellaneous Tools and Equipment onto a Transportation Cask, 
Transfer Cask, or MSC with Outer Lid Removed and Inner Lid In Place but 
Unbolted or with an Exposed DPC 
Assumption: An operational requirement is assumed to limit lift heights for tools and 
equipment associated with transportation cask, transfer cask, MSC, and DPC handling and 
preparation to the minimum necessary for operational purposes. The operational requirement 
will ensure that tools and equipment, including handling equipment, if dropped from the height 
limit, will not initiate an event sequence if dropped onto or collided against a transportation cask 
or MSC with outer lid removed and inner lid in place but unbolted, with an exposed sealed DPC, 
or with a DPC with its severed lid in place. Rationale: This assumption is needed to render the 
likelihood of these events to Beyond Category 2. The requirements are achievable because 
operational needs are accommodated and the tools and equipment are not massive structures that 
could cause a deformation of the inner lid. 
5.1.1.33 Heavy Loads Not Lifted Over or Near Transportation Casks, Transfer Casks, 
or WPs 
Assumption: An operational requirement will ensure that heavy loads that could potentially 
initiate an event sequence if dropped onto a transportation cask, transfer cask, or WP will not be 
lifted over or near a transportation cask, transfer cask, or WP, except as needed for transfer and 
closure operations (which are necessary operational sequences whose hazards are appropriately 
addressed in Section 6). Rationale: Lifts that are necessary for transfer and closure operations 
are not addressed by this assumption and are categorized as appropriate in other sections. This 
assumption is needed to eliminate Category 1 or Category 2 event sequences that can be 
precluded by operational rules. The requirement is achievable because it does not affect the 
operations that are necessary for transfer and closure operations. 
5.1.1.34 Numbers of Assemblies per Transportation Cask or MSC 
Assumption: Transportation casks, transfer casks, DPCs, or MSCs containing CSNF assemblies 
contain at most 74 BWR or 36 PWR assemblies. A design requirement will ensure that MSCs 
have equal or lower capacities. Rationale: The BNFL Fuel Solutions TS-125 cask can hold 74 
BWR assemblies. The NAC-STC cask can hold 36 PWR assemblies. Other licensed casks have 
lower capacities (BSC 2003 [DIRS 166015], Table 2-4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 43 April 2005 
5.1.1.35 SRTC Carrying a Cask or an MSC will Not Derail 
Assumption: A design requirement will ensure that an SRTC carrying a cask without impact 
limiters (typically only within structures) or an MSC will not derail and the cask or MSC will not 
fall from the SRTC under normal operating conditions or as the result of a collision. Rationale: 
This assumption is needed to prevent breaching the MSC and the DOE SNF canisters that may 
be inside the MSC. The requirement is achievable because passive features that prevent tilting 
and derailment can be incorporated into the design of the SRTC and the rails. 
5.1.1.36 Stability of Transfer Trolleys 
Assumption: A design requirement will ensure that loaded transfer trolleys will not derail or 
drop their loads. Design requirements will apply to trolleys for casks, WPs, MSCs, and DPCs. 
Rationale: This assumption is needed to prevent a release from the DOE SNF canisters that may 
be inside the WP, MSC, or cask on the trolley. For DPCs, this assumption is used for defense-indepth 
purposes. The requirement is achievable because passive features that prevent tilting and 
derailment can be incorporated into the design of the trolley and the rails. 
5.1.1.37 Consideration of 2-Over-1 Events 
Assumption: Portions, parts, subparts, or subsystems, of a non-ITS SSC which, upon failure, 
could adversely interact with an ITS SSC and prevent its safety function from being performed 
shall be classified as ITS or redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC. For seismic interactions, portions, parts, subparts, or subsystems, of an 
otherwise non-ITS structure, system, or component (SSC) shall be classified as ITS and shall be 
designed to the same seismic DBGM as the ITS SSCs subjected to the potential unacceptable 
interaction, or the non-ITS SSC may be redesigned to eliminate the potential unacceptable 
interaction. Rationale: Within the commercial nuclear power industry, the accepted practice is 
to include design features that prevent or mitigate the adverse impact of a non-safety related SSC 
on a safety related SSC. This allowance is in conformance with Regulatory Guide 1.29, ([DIRS 
103311], Section C.2) and 10 CFR 100 ([DIRS 173162], Appendix A, Section VI). This 
interaction is generally referred to as 2-over-1. This assumption provides for either removing 
the adverse impact by redesigning the affected portion of the non-ITS SSC or by making the 
affected portion of the SSC ITS based on its function to prevent or mitigate the adverse impact 
on an ITS SSC. 
5.1.1.38 Speed Limits for SRTCs and MSC Transporters 
Assumption: Design and operational requirements will establish speed limits such that a 
collision with shield or airlock doors or other heavy objects would not overturn an SRTC or 
MSC transporter or cause it to lose its load. Rationale: This assumption is needed to prevent a 
release from the DOE SNF canisters that may be inside the cask on the conveyance. Design 
calculations will establish maximum speeds for conveyances. The requirement is achievable 
because low speeds are preferable for effective normal operations, the conveyances can be 
provided with collision-mitigation features such as bumpers, and because the loads can be 
attached securely to the conveyances.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 44 April 2005 
5.1.1.39 Collision of a WP Transporter with WP on Turntable does not Breach the WP 
Assumption: Design and operational requirements will ensure that the WP transporter or its 
bedplate will not collide with a WP on the turntable and cause a WP breach. Rationale: This 
assumption is needed to prevent a release from the DOE SNF canisters that may be inside a WP 
or cask on the conveyance. Design calculations will establish maximum speeds for conveyances. 
The requirement is achievable because low speeds are preferable for effective normal operations, 
the transporter can be provided with collision-mitigation features such as bumpers, and because 
the WP can be attached securely to the turntable. 
5.1.1.40 Load Paths Kept Free of Puncture Hazards and Curbs 
Assumption: Design and operational requirements will ensure that surfaces in the load paths 
through which WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer 
casks, or MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement will ensure that the 
load paths are kept free of movable puncture hazards. Rationale: This assumption is needed to 
prevent event sequences that would damage waste forms in a way that would cause drop-height 
limits to be ineffective at preventing breach or would violate the conditions that were assumed to 
develop source terms for consequence calculations. The requirement is achievable because the 
facility can be designed to avoid the need for objects that could cause a puncture in case of a 
drop. Procedural controls can ensure that temporary or transient items are removed prior to 
commencement of operations. 
5.1.1.41 Operating Requirements for Portable Platforms, Access Platforms, Mobile 
Elevated Platforms, and Forklifts 
Assumption: Operational requirements will ensure that the portable platforms, access 
platforms, mobile elevated platforms, and forklifts operated in the facility are not operated in a 
manner that could breach or overturn a loaded transportation cask or MSC. Rationale: These 
operational requirements are needed to prevent event sequences initiated by inappropriate 
operation of mobile equipment. 
5.1.1.42 Lift-Height Limits for Naval Canisters 
Assumption: A design requirement will limit lift heights for naval canisters in vertical 
orientation to less than 28 ft (8.5 m) above the floor of a cask or WP; and 2 ft (0.6 m) above the 
floor of the transfer cell where orientation is not constrained to vertical. Rationale: The lift 
height for the naval canister is based on drop scenarios provided to the U.S. Navy (Cogema 2004 
[DIRS 169064], Section 5.3 and Attachment 2). The naval canister is considered to breach as a 
result of a drop. The requirement is needed to preserve the validity of the source terms provided 
by the Navy. 
5.1.1.43 Lift-Height Limits for DPCs 
Assumption: A design requirement will limit lift heights for DPCs to less than 23 ft (7 m) 
above the floor of a transportation cask, transfer cask, or MSC and 2 ft (0.6 m) above the floor of 
the transfer cell. Rationale: This assumption is made to ensure that lift heights are kept within
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 45 April 2005 
reasonable limits consistent with lift-height limits for standardized DOE SNF canisters (Section 
4.1.18). This allows appropriate source terms for the breach of a DPC to be chosen for the 
consequence analysis. The requirement is achievable because design features can limit lift 
heights. 
5.1.1.44 Drop of Outer Lid onto Inner Lid of Cask does not Breach DOE SNF Canister 
Inside 
Assumption: Operational requirements will establish permissible lift heights to ensure that a 
drop of a cask outer lid onto the inner lid of a loaded DOE SNF transportation cask or MSC will 
not breach a DOE SNF canister inside. Canisters included are standardized DOE SNF canisters 
and MCOs. Rationale: This assumption is needed to ensure that DOE SNF canisters are not 
breached. The requirement is achievable because: 
 Only modest lift heights are operationally required for the lid 
 The inner lid and the basket structure inside the cask protect the contents of the cask. 
5.1.1.45 Allowable Temperature Limits for Waste Forms in Air 
Assumption: Allowable temperature limits will be established for waste forms for a loss of 
HVAC, including Surface Nuclear and Surface Industrial HVAC systems, for up to 30 days in 
areas where SNF or HLW is handled or staged. Rationale: Temperature limits that are given in 
existing requirements documents may not provide adequate protection against oxidation for 
CSNF assemblies with perforated cladding in air. A thorough consideration of the consequences 
of exposure of CSNF to air for prolonged periods may result in new temperature limits or new 
approaches to prevent radiological releases in excess of those considered in the consequence 
analysis for normal operations. If temperature restrictions alone are unable to suitably limit 
oxidation, it may be necessary to change the design to introduce inerting in areas where SNF is 
handled or staged. However, inerting is not described in the design that forms the basis for this 
analysis. Other waste forms (naval SNF, DOE SNF, and HLW) are not exposed directly to air, 
but temperature limits are still required to ensure containment within the canisters. Temperature 
limits from existing requirements documents are expected to be adequate for waste forms other 
than uncanistered CSNF. Time periods beyond 30 days need not be considered because 
ventilation can be reliably restored within that time by bringing in alternate sources of power or 
installing replacement parts. 
5.1.1.46 Lift-Height Limits for CSNF Assemblies 
Assumption: A design requirement will limit lift heights for CSNF assemblies to less than 28 ft 
(8.5 m) above an essentially unyielding surface. Rationale: This assumption provides a basis 
for choosing a source term for the consequence calculations. The requirement is achievable 
because design features can limit lift heights. 
5.1.1.47 HEPA Filter Maintenance Prevents Filter Fire 
Assumption: Operational requirements will ensure that the operating surface temperatures of all 
high-efficiency particulate air (HEPA) filters will be maintained such that they will not catch fire
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 46 April 2005 
under normal operation or in the event of a shutdown of the HVAC systems. Rationale: This 
assumption is needed to ensure that HEPA filters do not catch fire and disperse accumulated 
radioactive material. The requirement is achievable by normal filter maintenance in areas where 
high radioactive loads will not be encountered. In the primary confinement areas of the DTF and 
FHF additional assurance is provided that the requirement is achievable by the requirement that 
normal operations will not be conducted unless the Surface Nuclear HVAC system is confirmed 
to be working properly (Assumption 5.1.1.48). Confirmation of proper operation of the HEPA 
filters does not allow the filters to become overly burdened with radioactive material. 
5.1.1.48 Availability of HVAC Including HEPA Filtration 
Assumption: A design requirement will ensure that the probability that the Surface Nuclear 
HVAC system, including HEPA filtration, which serves the primary confinement areas of the 
DTF and FHF becomes unavailable during a 4-h mission time (that is, the 4-h period following 
an arbitrarily timed event) is 0.01 or less without credit for backup electrical power. An 
operational requirement will ensure that the Surface Nuclear HVAC System is working properly 
before normal operations begin, that the system is monitored for proper operation, including 
HEPA filter condition, during normal operations, and that normal operations are suspended if the 
system becomes unavailable. Rationale: This assumption is needed to ensure that the HVAC 
system is working during and after Category 1 drops and collisions involving CSNF assemblies. 
A 4-h period is selected as a reasonable amount of time for HVAC circulation to clean the air in 
the cell. The requirement is reasonable because the hourly HVAC failure rate corresponds to 
0.01/4 h = 2.5  10-3 h-1, which can be met with ordinary HVAC technology without credit for 
backup power, as shown in the following scoping assessment. Dominant causes of a HVAC 
failure are mechanical failure and a loss of power. The frequency of a loss of offsite power is 
conservatively taken at 0.1 offsite power loss/year based on Assumption 5.2.2.1. This 
corresponds to an hourly failure rate of (0.1 y-1)/(365 day/year)/(24 h/day) = 1.1  10-5 h-1. 
Another cause of unavailability of power to the HVAC system is the failure of the electrical 
supply system that makes the connection between offsite power and the powered HVAC 
equipment. The dominant failure mode in that case is a spurious operation of an electrical 
component such as a switch, a circuit breaker or a relay. Eide and Calley (1993 [DIRS 146564], 
Table 2) report a failure rate associated with this failure mode of 10-6 h-1. Therefore, it is 
reasonable to consider that the contribution of spurious operations of electrical components to 
the global failure rate of the electrical supply of the HVAC will remain lower or at most 
comparable to the frequency of loss of offsite power. The failure rate of the electrical system 
supporting the HVAC will be a small fraction of the 2.5  10-3 h-1 that is acceptable for the 
HVAC system. Concerning the mechanical failure of the HVAC system, typical failures would 
involve ventilators failing to run, or dampers operating spuriously. Eide and Calley (1993 [DIRS 
146564], Table 1) indicate that the failure rate for a ventilator is typically 3.0  10-5 per hour, and 
that dampers operate spuriously at a rate of 3.0  10-7 per hour. Here also, it is seen that these 
failure rates represent a small fraction of the 2.5  10-3 h-1 that is acceptable for the HVAC 
system Therefore, the reliability requirement for the HVAC system can be met without taking 
credit for backup power to the HVAC system.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 47 April 2005 
5.1.1.49 No Normal Operations When Offsite Power Is Unavailable 
Assumption: An operational requirement will ensure that offsite power is available before 
normal operations begin and that normal operations are suspended if offsite power becomes 
unavailable. Rationale: This assumption is needed to prevent dependence on emergency power, 
which is not credited in the safety analysis. Because emergency power is not credited in 
determining the availability of the HVAC system that serves the primary confinement areas of 
the DTF and FHF (Assumption 5.1.1.48), its availability cannot be relied upon for normal 
operations. Therefore, normal operations may not take place without the availability of offsite 
power. 
5.1.1.50 Restriction on Carrying Empty Casks or MSCs in the DTF Remediation Pool 
Assumption: An operational requirement will prohibit carrying an empty cask in the DTF 
remediation pool above a transportation cask, MSC, or basket that contains CSNF. Rationale: 
There is no operational need to carry an empty cask as described. 
5.1.1.51 Hydrogen Accumulation From Batteries for Powering Heavy Equipment 
Insufficient for an Explosion 
Assumption: Operational controls pertaining to batteries for powering heavy equipment will 
prevent the generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, MSC, or WP. Rationale: This requirement is needed to prevent 
explosions leading to radiological releases. 
5.1.1.52 Lift-Height Limits for Unsealed WPs 
Assumption: Design and operational requirements specify lift height limits for unsealed WPs 
wherever unsealed WPs are transferred. If the limit cannot be met, impact absorbers may be 
used. The impact absorbers shall limit the impact energy for a dropped unsealed WP to be less 
than or equal to the impact energy associated with a dropped unsealed WP on an unyielding 
surface from the maximum specified drop height. The allowable lift height above an essentially 
unyielding surface depends on the nature of the drop and the contents of the WP as follows: 
 Drops for which the WP may topple and overturn or slap down ....................2 ft (0.6 m) 
 Flat-bottom drops (e.g., in a WP loading pit) where WP remains upright 
 Naval SNF or CSNF................................................................................ 28 ft (8.5 m) 
 HLW Canisters or DOE SNF canisters ................................................... 23 ft (7 m) 
For MCO canisters, a flat-bottom drop is defined as an impact on a horizontal surface for which 
the axis of the canister is within 3 degrees of vertical (Section 4.1.18). For waste forms other 
than MCOs, a flat-bottom drop means that the WP must remain upright after the impact. For 
WPs that contain canisters, the WP and the basket structure within the WP must prevent stresses 
on the canisters in excess of the stresses imposed by a drop of a canister alone. 
Rationale: The 2-ft limit for lifts where toppling and overturning are possible is based on limits 
given in Assumption 5.1.3.11 and Section 4.1.18 and also provides a specification that the device
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 48 April 2005 
to prevent spilling of WP contents must meet (Assumption 5.1.3.11). The 28-ft limit for naval 
WPs is based on the limit for canister drops given in Assumption 5.1.1.42. The 28-ft limit for 
CSNF WPs is based on the limit given in Assumption 5.1.1.46. The 23-ft limit for WPs that 
contain DOE SNF is derived from the structural capabilities of DOE SNF canisters (Section 
4.1.18). The 23-ft limit for WPs that contain HLW is based on the limit given in Assumption 
5.1.1.24. 
5.1.1.53 Prevention of Backward Slapdowns Associated with the Tilting Machine for 
WPs 
Assumption: A design requirement will prevent backward slapdowns associated with the tilting 
machine for WPs. The design requirement for the tilting machine will include measures to 
prevent movement or release of the lock on WP trunnions while the WP is being lowered onto 
the emplacement pallet. Rationale: This assumption is needed to dispense with a potential 
event that is unlikely to occur but could result in a waste-package breach. The requirement is 
achievable because it can be prevented with passive design features. See Section 5.1.3.12 for 
additional drops and tipover events. 
5.1.1.54 Handling Equipment Collision with a CSNF Assembly 
Assumption: A design requirement will ensure that the spent fuel transfer machine, fuel 
handling machine, and other equipment designed to handle individual CSNF assemblies are not 
capable of lateral movements of handling equipment at a speed that could breach a CSNF 
assembly as a result of collision. Rationale: The requirement is achievable because the low 
transfer speeds are preferable for effective normal operations. Collisions resulting from rapid 
descent of the equipment are considered drops. A collision that does not cause breach could 
dislodge radioactive crud from the surface of the assembly. The dislodgement of crud is 
considered part of normal operations (Section 7.4). 
5.1.1.55 Suspension of a Lid Grapple Above an Open WP or DPC 
Assumption: An operational requirement will prohibit suspending a lid grapple above an open 
WP or DPC unless the lid is in place or is being lifted. Rationale: There is no operational need 
to suspend a lid grapple above a WP or DPC unless the lid is in place or is being removed. 
5.1.1.56 Suspension of an Empty Canister for CSNF in the DTF Remediation Pool 
Assumption: An operational requirement will prohibit suspending an empty single-element 
canister for CSNF above an open cask, MSC, or CSNF basket that contains CSNF. Rationale: 
There is no operational need to suspend an empty canister as described. 
5.1.1.57 Prevention of Inadvertent Actuation of Shield Doors and Pit Covers 
Assumption: Design and operational requirements will ensure that exposure of workers due to 
inadvertent actuation of shield doors or pit protective covers will not be Category 1. Rationale: 
This assumption is needed to account for inadvertent worker exposures that could occur as a 
result of operational errors or equipment malfunctions. The requirement is achievable because
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 49 April 2005 
design features such as interlocks and provisions in operating procedures such as checkoffs and 
redundancies can ensure low probability of failure. 
5.1.1.58 Sampling and Purging To Preclude Hydrogen Explosion 
Assumption: Operational requirements will provide reasonable assurance in accordance with 10 
CFR 63.102(f) [DIRS 158535] that hydrogen explosions will not occur during sampling and 
purging operations in association with opening (a) DPCs or (b) transportation casks, MSCs, or 
WPs that contain bare CSNF assemblies. Rationale: Section 4.3.6 specifies requirements for 
sampling and purging transportation casks, DPCs, and WPs. Similar, and possibly more explicit, 
requirements can be established for sampling and purging transportation casks, DPCs, WPs, and 
MSCs to avoid hydrogen explosions. Because hydrogen explosions will not be possible where 
canisters provide containment within the cask, MSC, or WP, there is no need for sampling and 
purging when canisters provide containment. 
5.1.1.59 Response to Loss of Confinement Prevents Significant Exposure to 
Radioactivity 
Assumption: Operating procedures will ensure that a loss of confinement in the CHF, DTF, 
FHF, or subsurface during otherwise normal operations will not cause individuals to be exposed 
to significant amounts of radioactivity. Rationale: The loss of confinement during otherwise 
normal operations poses a threat of increases in worker exposure, but negligible increases in 
public exposure. This assumption is suitable for use because operating procedures will provide 
for responses such as suspension of normal operations until confinement is restored and 
evacuation of adjoining areas as required until confinement is restored. With appropriate 
operating procedures in place, a loss of confinement during otherwise normal operations will not 
expose individuals to radiation doses in excess of operational limits. 
5.1.1.60 Not used 
5.1.1.61 Prevention of Trolley Load Drops Due to Collisions 
Assumption: A design requirement will limit the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. Rationale: Design 
calculations will establish maximum speeds for trolley movements. The requirement is 
achievable because passive features of the trolley design may be used to preclude high speeds. 
5.1.1.62 Not used 
5.1.1.63 Not used 
5.1.1.64 Collection of Radioactive Contamination From Cleanup Activities 
Assumption: An operational requirement will ensure that radioactive contamination that is 
collected during cleanup activities in transfer cells is handled in a manner that precludes nuclear 
criticality. Rationale: Normal operations of the facility will include some release of particles of 
CSNF from failed cladding. Careless handling of the waste generated during cleanup activities 
could result in an accumulation of fissile material with the potential for criticality. The assumed
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 50 April 2005 
requirement will ensure that the potential for criticality is recognized and avoided. The 
requirement is achievable because procedures for handling fissile material are commonly used in 
facilities with similar risks. 
5.1.1.65 Durations of the Preclosure Period and of Emplacement Activities 
Assumption: An operational requirement will limit the duration of the preclosure period to 100 
years or less and the duration of emplacement activities to 50 years or less. Rationale: A 
preclosure period of 100 years duration accommodates forced ventilation of the repository for 50 
years following a period of waste emplacement of up to 50 years. 50 years is a reasonable upper 
limit for the useful life of applicable surface structures and allows ample time for waste 
emplacement. Should a decision be made to retrieve waste, operate the surface facility for more 
than 50 years, or operate the subsurface facility for more than 100 years, the appropriate 
preclosure safety analyses would be revised and necessary approvals from the U. S. Nuclear 
Regulatory Commission would be sought.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 51 April 2005 
5.1.2 Assumptions Related to External Hazards 
5.1.2.1 Cranes, Gantries, and Spent Fuel Transfer Machines, and Fuel Handling 
Machines Stop and Retain Load on Loss Of Power 
Assumption: A design requirement will ensure that cranes, spent fuel transfer machines, fuel 
handling machines, and gantries that are used for handling waste forms following a loss of power 
will stop, retain their loads, and enter a locked mode; upon a restoration of power, cranes shall 
stay in the locked mode until operator action is taken. Rationale: This assumption is needed to 
prevent Category 1 or Category 2 event sequences initiated by loss of power. The requirement is 
achievable because such features are available on current crane designs. 
5.1.2.2 Trolleys and Transporters Stop and Retain Load on Loss of Power 
Assumption: A design requirement will ensure that trolleys and transporters that are used for 
handling HLW or SNF are designed to stop, retain the load, and enter a locked mode; upon a 
restoration of power, they shall stay in the locked mode until operator action is taken. 
Rationale: This assumption is needed to prevent Category 1 or Category 2 event sequences 
initiated by loss of offsite power. The requirement is achievable because such features are 
available on current designs of similar equipment. 
5.1.2.3 Adequacy of Transportation Casks and Transfer Casks for Staging and 
Movement on Site 
Assumption: Transportation casks and transfer casks on the repository site provide adequate 
protection against external hazards. Rationale: Functions of the transportation casks are 
credited to prevent or mitigate event sequences. The certification process for transportation 
casks under 10 CFR Part 71 [DIRS 171308] considers severe transportation accident conditions 
and conditions of normal transport. Transfer casks are expected to be similar to transportation 
casks (BSC 2004 [DIRS 171161] Section 4.1.1.2). The precedent that licensed casks provide 
adequate protection against all hazards that apply during the transportation phase establishes the 
basis that transportation casks and transfer casks will provide adequate protection against 
external hazards on site at the repository. 
5.1.2.4 Thermal Response of Waste-Handling Areas to a Loss of HVAC 
Assumption: A design requirement will ensure that a loss of HVAC, including Surface 
Industrial and Surface Nuclear HVAC Systems, for up to 30 days in areas where SNF or HLW is 
handled or staged would not cause waste-form temperatures to exceed allowable limits. 
Rationale: Allowable temperature limits will be established for a loss of HVAC for up to 30 
days (Assumption 5.1.1.45). Temperature limits are needed to ensure that a ventilation loss 
would not cause radiological releases in excess of those considered in the consequence analysis 
for normal operations. Time periods beyond 30 days need not be considered because ventilation 
can reliably be restored within that time by bringing in alternate sources of power or installing 
replacement parts. 
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 52 April 2005 
5.1.2.5 Loss of Pool Water 
Assumption: A design requirement will ensure that the pool and pool area in the remediation 
system are designed such that any lost water can be replaced with make-up water until the cause 
of the loss is corrected or waste forms are removed from the pool. The minimum available rate 
of make-up water shall be sufficient to replenish evaporation and the maximum potential leakage 
in the event of the failure of the recirculating cooling system over the minimum time period 
required to remove waste forms from the pool. The rate shall also be sufficient to prevent the 
uncovering of the waste forms over this same period. Rationale: This assumption is needed to 
prevent initiation of Category 1 or Category 2 event sequences due to malfunctions involving the 
water supply and recirculation system. Loss of pool inventory could be caused by gross pool 
leakage or pump out (or siphon loss caused by failure of the siphon breakers) due to a failure of 
the recirculating cooling system. Minor pool leakage would be made up by the make-up system 
or by operator action. Due to the large pool inventory and age of the CSNF assemblies (i.e., 
greater than 5 years), long times would be available to provide make-up water. The requirement 
is achievable because passive design features such as locating pool outlets near the top of the 
pool could be used to prevent rapid loss of water. 
5.1.2.6 Prevention of Puncture of the Pool Liner 
Assumption: Design and operational requirements will ensure that the remediation pool is 
designed with the appropriate impact-absorbing capability and limitations on heavy load carrying 
cranes to prevent loss of pool integrity, given a drop of the most challenging transportation cask 
or MSC into the pool. Rationale: The requirement is achievable because lift-height limits and 
passive design features such as impact-absorbing material lining the bottom of the pool could be 
used to prevent puncture of the liner. 
5.1.2.7 Ash Fall 
Assumption: A design requirement will ensure that the surface facilities, including the SNF 
Aging System, where SNF and HLW are handled or stored are designed to withstand the effects 
of ash fall from a regional volcanic eruption without loss of capability to perform their safety 
function (BSC 2004 [DIRS 167266], Section 6.4.53). Rationale: This assumption is needed to 
provide assurance in accordance with 10 CFR 63.102(f) [DIRS 158535] that ash fall will not 
initiate an event sequence. The roof live load requirement of 21 lb/ft2 (BSC 2004 [DIRS 
167266], Section 6.4.53) is achievable by design. 
5.1.2.8 Not used 
5.1.2.9 Inspection of Vent Paths of SNF Aging Casks 
Assumption: An operational requirement will ensure that filters or natural circulation vent paths 
of SNF aging casks (including MSCs and HAMs) that could be clogged as a result of a 
sandstorm or other events or chronic conditions are inspected and maintained in an operable 
condition. Clogging found will be removed before the design basis thermal response of the casks 
are exceeded. Rationale: This assumption is needed to prevent Category 1 or Category 2 event 
sequences. These openings are inspected and maintained in an operable condition. The
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 53 April 2005 
requirement is achievable because similar operational and procedural directives are 
commonplace in installations that are comparable to the repository.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 54 April 2005 
5.1.3 Assumptions Related to WPs 
5.1.3.1 No Criticality in Sealed WP 
Assumption: A design requirement will ensure that sealed WPs are designed such that drops, 
collisions, and other handling impacts within their design bases (allowing for rearrangement of 
container internals, proximity of other sealed waste packages, and without credit for burnup) 
cannot lead to a nuclear criticality. Rationale: This assumption is required to ensure criticality 
safety in sealed WPs. Loading restrictions based on burnup and enrichment provide defense in 
depth for preclosure safety. The requirement is achievable because moderator is excluded by 
maintaining the integrity of the WP. 
5.1.3.2 No Criticality in Open WP 
Assumption: A design requirement will ensure that WPs are designed such that, with credit for 
moderator control (Assumption 5.1.1.21) and without credit for burnup: 
 WPs configured for CSNF can be loaded with any combination of CSNF assemblies that 
are acceptable for disposal without leading to a preclosure nuclear criticality. 
 DOE codisposal WPs can be loaded with any combination of DOE canisters (including 
standardized DOE SNF canisters, MCOs, and HLW canisters) that will fit in the basket 
positions without leading to a preclosure nuclear criticality. 
 Naval WPs can be loaded with a naval SNF canister without leading to a preclosure 
nuclear criticality. 
The demonstration of criticality safety must account for the bowing of fuel rods or other 
rearrangement of fissile material that may occur due to a drop or other handling incident. 
Rationale: This assumption is required to ensure criticality safety in unsealed WPs. Its purpose 
is to prevent preclosure criticality in WPs without reliance on loading restrictions based on 
burnup and enrichment. 
5.1.3.3 Drop or Collision of Equipment onto a WP or Partially Sealed WP (Including 
WP with a Known Weld Defect) 
Assumption: Operational requirements will establish lift-height limits for handling equipment 
and other equipment associated with the WP, including lifting collars (or trunnion collars), 
yokes, docking rings, and WP-closure equipment. The lift-height limits will ensure that the 
handling equipment will not breach a sealed WP if the equipment is dropped onto or collided 
into the WP from within the lift-height limit. Furthermore, the lift-height limits will be 
established such that a drop of equipment from within the lift-height limit will not breach a waste 
form if the WP inner lid is in place, but unsealed. An operational requirement will ensure that 
the inner lid, once set in place, is not removed from the WP except in a remediation situation. 
Rationale: This assumption is needed to dispense with possible events with little potential to 
initiate an event sequence. The requirements are achievable because WPs are rugged containers 
and lifts of handling equipment high above the WP are not needed for operational reasons.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 55 April 2005 
5.1.3.4 Not used 
5.1.3.5 Not used 
5.1.3.6 Fraction of WPs Requiring Remediation 
Assumption: No more than 10 percent of WPs will require remediation in the Remediation 
Facility due to unsuccessful closure, handling incident, or other reason. Rationale: This 
assumption is needed to reduce the likelihood of breaches of DOE SNF canisters to Beyond 
Category 2 when unsealed WPs are dropped in the Remediation Facility. This assumption is 
achievable because a 10 percent rate of defective, damaged, or otherwise suspect WPs would be 
considered unacceptable with respect to repository operations. If such a rate were experienced, it 
is reasonable to believe that design or operational changes would be implemented to reduce the 
fractions processed through the dry remediation area to below 10 percent. Therefore, 10 percent 
is a bounding fraction for the categorization calculations. 
5.1.3.7 Not used 
5.1.3.8 Lift-Height Limit for WP on an Emplacement Pallet 
Assumption: Design and operational requirements will ensure that WPs in horizontal orientation 
on the emplacement pallet will not be lifted such that the bottom of the pallet is higher than 6.5 ft 
(2.0 m) above an essentially unyielding surface. Rationale: This assumption is provided to 
avoid breaching the sealed WP. The requirement is achievable because the facility has been 
designed to accommodate the maximum lift height for WPs (Assumption 5.1.3.12). 
5.1.3.9 Lift-Height Limit for Sealed WP in Vertical Orientation 
Assumption: Design and operational requirements will ensure that sealed WPs in vertical 
orientation will not be lifted higher than 3.3 ft (1.0 m) (for naval long WP) or 6.5 ft (2.0 m) (for 
other WPs) above an essentially unyielding surface (as measured from the bottom of the WP). 
The heights may be exceeded where impact absorption by crush pads or other features is 
credited. The crush pads shall limit the impact energy for a dropped WP to be less than or equal 
to the impact energy associated with a dropped WP on an unyielding surface from the maximum 
specified drop height. Rationale: This assumption is needed to prevent breaching the sealed 
WP. The requirement is achievable because the design may either meet the maximum lift 
heights for WPs (Assumption 5.1.3.12) or provide a means of impact absorption, such as crush 
pads, wherever the limits cannot be met. Analyses will confirm that sealed WPs will withstand 
drops onto energy absorbing crush pads without breaching. 
5.1.3.10 Impact or Collision of Trunnion Collar Removal Machine, WP Turntable, or 
WP Tilting Machine with WP Will Not Breach WP 
Assumption: A design or operational requirement will ensure that an impact or collision 
between the trunnion collar removal machine, WP turntable, or WP tilting machine and a WP 
will not breach the WP or cause it to fall off the emplacement pallet. Rationale: This 
assumption is needed to dispense with a low-energy collision event that will not initiate an event
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 56 April 2005 
sequence. The requirement is achievable because the speed of the trunnion collar removal 
machine and the WP turntable can be limited to preclude waste-package breach. 
5.1.3.11 Dropped Unsealed WP Does Not Spill its Contents 
Assumption: A design requirement will ensure that an unsealed WP that is dropped onto an 
essentially unyielding surface from within its lift-height limits (Assumption 5.1.1.52) will not 
spill its contents. Rationale: This assumption is needed to prevent a reconfiguration of fissile 
material that is unanalyzed in the criticality safety calculations and to prevent fuel damage that is 
not consistent with the radiological source terms to be used in the consequence calculations. The 
requirement is achievable because installation of the inner lid and spread ring, possibly with 
auxiliary measures such as a mechanical locking fixture, could keep the contents in place when 
the waste package is unsealed. 
5.1.3.12 Design Requirements for WP Drops and Tipover 
Assumption: Design requirements will ensure that WPs (except as noted) will withstand 
without breaching the following drops: 
 Free drop of 7.8 ft (2.4 m) onto a horizontal surface from horizontal orientation. 
(trunnion collars installed) 
 Free drop of 6.5 ft (2.0 m) onto a horizontal surface from vertical orientation. The 
height limit for the naval long WP is 3.3 ft (1.0 m). (trunnion collars installed) 
 Free drop of WP and emplacement pallet onto a horizontal surface from horizontal 
orientation with the initial condition that the bottom of the emplacement pallet is 6.5 ft 
(2.0 m) above the horizontal surface. (trunnion collars not installed) 
 Tipover onto a horizontal surface from a 6.5 ft (2.0 m) elevated surface. The height 
limit for the naval long WP is 1.6 ft (0.5 m). (trunnion collars installed) 
 Tipover during placement onto the tilting machine, including contact with trunnion 
cradles or the floor. (trunnion collars installed) 
Drop and tipover event sequences are evaluated for the most damaging credible, conditions 
including initial orientation and weight of contents. An unyielding, flat horizontal surface may 
be used to bound consequences of an event, or credible countermeasures may be used to mitigate 
consequences of a drop. Drops include attendant swingdown or slapdown from the indicated 
orientation. 
Rationale: The requirement to survive a slapdown into the tilting machine is achievable because 
design of tilting machine can be made to accommodate the event without breaching the WP. The 
other requirements are achievable because these events are considered in the design of the WP 
(BSC 2004 [DIRS 172035], Section 3). See Section 5.1.1.53 for backward slapdowns.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 57 April 2005 
5.1.4 Assumptions Related to the DTF (Excluding Remediation and DPC Cutting) 
5.1.4.1 Preclusion of Contact Between CSNF Assemblies and Staged Canisters 
Assumption: An operational requirement will preclude contact between a CSNF assembly and 
a staged canister. Rationale: This assumption is credited to avoid the need to consider the 
consequences of dropping a CSNF assembly into a canister staging rack. The requirement is 
achievable because some means of preventing contact, such as limiting the range of motion of 
the spent fuel transfer machine or requirements to cover staging tubes, can be used. 
5.1.4.2 Criticality Safety for Dry CSNF Assembly Staging Racks (Normal Operation) 
Assumption: A design requirement will ensure criticality safety for CSNF assembly staging 
racks loaded to capacity with the most reactive CSNF assembly accepted at the repository with 
moderator control in effect. Rationale: The requirement is achievable because CSNF 
assemblies are designed for water-cooled reactors in which water is essential to achieve 
criticality. Criticality calculations will determine which features, if any, of the rack design are 
required to maintain criticality safety with moderator control in effect. 
5.1.4.3 Criticality Safety for Dry CSNF Assembly Staging Racks (Given a Drop) 
Assumption: A design requirement will ensure criticality safety for CSNF assemblies dropped 
into or onto a CSNF assembly staging rack with moderator control in effect. Rationale: The 
requirement is achievable because CSNF assemblies are designed for water-cooled reactors in 
which water is essential to achieve criticality. Criticality calculations will determine which 
features, if any, of the rack design are required to maintain criticality safety for dropped fuel 
elements with moderator control in effect. 
5.1.4.4 No Lifting Canisters Above Staged CSNF Assemblies 
Assumption: An operational requirement will prohibit carrying DOE HLW canisters or DOE 
SNF canisters over or near the staging racks for CSNF. Rationale: This assumption is needed 
to avoid having to consider the consequences of drops or collisions of canisters into the CSNF 
assembly staging racks The requirement is achievable because there is no operational need to 
carry canisters over the staging racks for CSNF.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 58 April 2005 
5.1.5 Assumptions Related to Remediation and DPC Cutting 
5.1.5.1 Limits on the Range of Motion of the Remediation-Pool Crane 
Assumption: An operational requirement will prohibit carrying a cask or MSC over or near the 
CSNF assembly staging rack in the pool. Rationale: This assumption is credited to prevent the 
need to consider the consequences of dropping a cask or MSC onto the CSNF assembly staging 
rack. The requirement is achievable because there is no operational need to carry casks or MSCs 
over or near the CSNF assembly staging rack. 
5.1.5.2 WP Lid-Cutting Machine Does Not Cause Radiological Release from the 
Unsealed WP 
Assumption: The lid-cutting machine shall be designed to preclude a radiological release due to 
damage inflicted upon the WP contents during the lid-cutting process. Rationale: This 
assumption is needed to dispense with identified events that may occur but have little potential to 
initiate an event sequence. The requirement is achievable because there is no operational need to 
lift the cutting machine above the WP, because the inner lid protects the contents of the WP, and 
because passive restraints on the range of motion of the cutting surfaces can be provided. 
5.1.5.3 DPC Survives Drop of Canister Cutting Machine 
Assumption: A design requirement will ensure that the mass, potential drop height, and other 
characteristics of the canister cutting machine are such that the DPC lid will prevent damage to 
the CSNF assembly resulting in a radiological release should the cutting machine fall onto or 
make contact with the DPC. Rationale: This assumption is needed to ensure that collision 
events involving the cutting machine will not initiate an event sequence. The requirement is 
achievable because the DPC lid will protect the waste from damage that could result in a 
radiological release. 
5.1.5.4 Canister Cutting Machine Does Not Cause a Radiological Release as a Result of 
Damage to the Contents of a DPC 
Assumption: The canister cutting machine shall be designed to preclude a radiological release 
due to damage inflicted upon the DPC contents during the cutting process. Rationale: This 
requirement is needed to preclude an unlikely event that could lead to a radiological release. It is 
achievable because the cutting surfaces can be limited in size such that they cannot penetrate far 
enough into the DPC to contact fuel assemblies. 
5.1.5.5 Drop or Collision of Canister Cutting Machine 
Assumption: An operational requirement will ensure that the canister cutting machine is not 
suspended over the open DPC after the lid is removed. Rationale: This assumption is needed to 
dispense with an identified event that may occur but has little potential to initiate an event 
sequence. The requirement is achievable because there is no operational need to suspend the 
cutting machine above the open DPC after the lid is removed.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 59 April 2005 
5.1.5.6 Characteristics of Lid-Bolt Detorque Machine in the Remediation Area 
Assumption: An operational requirement is assumed to ensure that the lift heights permitted for 
the lid-bolt detorque machines in the dry-handling cell and the pool area are such that the lid of 
the transportation cask or MSC (without credit for the bolts) will be able to prevent damage to 
the waste form resulting in a radiological release should the detorque machine fall onto or collide 
with the transportation cask. Rationale: This assumption is needed to dispense with an 
identified event that may occur but has little potential to initiate an event sequence. The 
requirement is achievable because the detorque machine is not a massive structure that could 
cause a deformation of the inner lid. 
5.1.5.7 Drop or Collision of an Empty CSNF Assembly Basket or Basket Grapple into 
or Against a Loaded Cask in the Pool 
Assumption: Operational requirements will ensure that a CSNF assembly basket or basket 
grapple dropped or collided against another basket or a cask in the pool will not damage CSNF 
assemblies in the basket or cask already in place. Rationale: This assumption is needed to limit 
the material at risk from a dropped basket to the contents of the dropped basket. The 
requirements are achievable because operational rules can be used to avoid the configurations 
from which the postulated events could occur. 
5.1.5.8 Criticality Safety for Baskets on Trolleys in Dry Remediation 
Assumption: An operational requirement will establish limited lift heights of heavy equipment 
above a CSNF assembly, a DOE SNF or HLW canister, or a DPC in a fuel basket on a trolley in 
the dry remediation area such that criticality as the result of equipment drop is precluded with 
moderator control (Assumption 5.1.1.21) in effect. Rationale: Design analysis will demonstrate 
criticality safety for fuel reconfigurations that could result from drops from the established lift 
heights. The requirement is achievable because moderator control will preclude criticality. 
5.1.5.9 Criticality Safety for CSNF Assembly Baskets and Staging Racks in the Pool 
Assumption: Design and operational requirements will ensure that: 
 Fully loaded baskets in staging racks are designed to be subcritical when fully flooded 
with pure water (i.e., no credit for neutron absorbers dissolved in the water) 
 Baskets are designed to have sufficient nuclear criticality controls to remain subcritical 
even if a handling incident causes a reconfiguration of the spent fuel. 
 Baskets are closed during handling. A closed basket being transferred in the pool will 
not spill CSNF assemblies into the pool if the basket is dropped. 
Rationale: This assumption is needed to ensure criticality safety in case of handling incidents in 
the pool. Design analysis will evaluate the criticality potential of baskets with variations in fuel 
assembly pitch that could be caused by handling incidents. The design of baskets or racks will 
provide geometry and neutron absorber to maintain subcritical conditions. The closure
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 60 April 2005 
mechanism for the basket can be made to prevent CSNF assemblies sliding out if the basket is 
dropped. 
5.1.5.10 Quenching Operations for Casks and MSCs 
Assumption: An operational requirement will ensure that quenching operations involving casks 
or MSCs holding CSNF are conducted to prevent radiological releases due to induced thermal 
stresses or steam explosion due to insufficient cooling. Rationale: This assumption is required 
to dispense with event sequences that pose little risk of initiating an event sequence. The 
requirement is achievable because quenching can be performed gradually such that it will not 
result in a loss of integrity.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 61 April 2005 
5.1.6 Assumptions Related to the CHF 
5.1.6.1 Shield Plugs for Canister Staging Pits or Racks Do Not Fit into the Opening 
Assumption: A design requirement will ensure that the shield plugs for the canister staging pits 
or racks will not fit far enough into the opening to breach a canister inside if the shield plug is 
dropped. Rationale: This assumption is needed to dispense with incidents with little potential 
to initiate an event sequence. The requirement is achievable because tapering the plug and the 
hole can ensure that the plug will not fit through the opening. 
5.1.6.2 Loaded WP not Carried Over a Loaded MSC/WP Loading Pit 
Assumption: An operational requirement will ensure that a loaded WP is not carried over or 
near a loaded MSC/WP loading pit. Rationale: This assumption is needed to dispense with an 
incident that could occur but can be rendered Beyond Category 2 by an operational requirement. 
It is achievable because there is no operational need to carry a WP over a loaded pit. Controls 
can be implemented to establish appropriate load paths for loaded WPs. 
5.1.6.3 Replacement of Waste-Package and MSC Pit Covers 
Assumption: An operational requirement will ensure that covers for the waste-package and 
MSC pits are replaced whenever individual waste-form handling operations are suspended unless 
loading operation in that particular pit is complete and the next operation involving the overhead 
crane is to remove the WP or MSC from the pit. Rationale: This assumption is needed to 
dispense with potential events that could occur but can be rendered Beyond Category 2 by 
operational requirements. The requirement is achievable because there is no operational need to 
keep pits open while moving loaded WPs. 
5.1.6.4 WP Trolley Kept in Positioning Cell When Opposite Trolley Is Out of Its 
Positioning Cell 
Assumption: An operational requirement will ensure that, whenever a waste-package is being 
loaded onto a trolley or is already on the trolley but not in the WP positioning cell, the opposite 
waste-package trolley remains in its positioning cell or otherwise out of the way. Rationale: 
This assumption is needed to dispense with potential events that could occur but can be rendered 
Beyond Category 2 by an operational requirement. The requirement is achievable because there 
is no operational need to have a loaded trolley present while loading the trolley from the other 
cell. 
5.1.6.5 Not used 
5.1.6.6 Sturdy Waste-Package and MSC Pit Covers 
Assumption: A design requirement will ensure that pit covers for the waste-package and MSC 
pits are sturdy enough to prevent a WP or MSC that is dropped onto the pit cover from 
penetrating the pit cover and falling into the pit. Rationale: This assumption is needed to 
dispense with potential events that could occur but can be rendered Beyond Category 2 by design 
and operational requirements. The requirement is achievable by designing thick pit covers.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 62 April 2005 
5.1.7 Assumptions Related to the WP Transporter 
5.1.7.1 Vehicle Crossings of the Railway Used by WP Transporter 
Assumption: An operational requirement will ensure that vehicle crossings of the railway will 
be controlled to ensure that the potential for collisions between vehicles and the WP transporter 
carrying a loaded WP is minimized. Rationale: It is reasonable to expect that enforceable rules 
for use of the roads will ensure that the potential for a surface vehicle to hit a loaded transporter 
in a manner such that a waste package breach may occur is Beyond Category 2. 
5.1.7.2 Speed Limitations on Transporter Shielded Enclosure Doors 
Assumption: A design requirement will ensure that movement of the transporter shielded 
enclosure doors will not breach the WP or cause it to fall from the bedplate of the transporter. 
Rationale: This assumption is needed to dispense with incidents with little potential to initiate 
an event sequence. The requirement is achievable by, for example, limiting the power of the 
engine that closes the doors. 
5.1.7.3 No WP Breach in Case of Derailment or Collision Involving Transporter 
(excluding Tipover) 
Assumption: A design requirement will ensure that the WP transporter transports the WP in a 
manner such that if a collision or derailment (excluding tipover) occurs, the WP impact energy 
will be low enough to preclude a WP breach. This translates into a maximum transporter speed 
of 15 mph. Rationale: This assumption is needed to limit the severity of potential derailments 
and collisions in which the WP transporter can be involved. The reliability analysis performed in 
Waste Package Transporter Preclosure Safety Analysis (BSC 2004 [DIRS 169554]) shows that it 
is possible to effectively prevent the transporter from exceeding allowable speeds. Limiting 
speed limits the impact energy of the WP in case of a derailment or a collision. The maximum 
speed value (15 mph) is based on Anderson (2005 [DIRS 172857]). 
5.1.7.4 Prevention of WP Ejection from Transporter 
Assumption: The restraints used to immobilize the bedplate inside the shielded compartment of 
the transporter and the mechanism for locking the doors of the shielded compartment shall 
withstand a collision or derailment (including tipover) of the transporter without resulting in a 
Category 1 or Category 2 event sequence. Rationale: This assumption is needed to ensure that 
a collision or derailment (including tipover) of the transporter will not cause the WP to be ejected 
out of the transporter. The requirement is achievable because credible derailments or collisions 
occur at a speed below the maximum allowable speed. Limiting speed limits the severity of 
potential impacts, which the bedplate restraints and door locking mechanisms can be designed to 
withstand without failing. 
5.1.7.5 Average Time Spent Underground by Transporter Carrying WP inside 
Shielded Compartment 
Assumption: An operating requirement will ensure that the average time during which the 
transporter carrying the WP inside the shielded compartment is underground does not exceed 6
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 63 April 2005 
hours per WP. Rationale: This assumption is used in the probability calculation of the mass of 
the bounding rockfall that could hit the shielded compartment of the transporter (Section 
6.3.6.1.9). The 6-hour duration is based on a conservative evaluation given in BSC (2004 [DIRS 
168508], Section 6.3.1), and yields an upper average value for the time spent by the transporter 
carrying the WP underground. The assumption therefore appears to be reasonable. Should, in 
practice, the average duration prove to exceed 6 hours, the bounding mass of the credible 
rockfalls that can impact the shielded compartment of the transporter would need to be reevaluated. 
5.1.7.6 Prevention of Spurious or Operator-Induced Opening of Shielded 
Compartment 
Assumption: Spurious or operator-induced opening of the WP shielded compartment followed 
by a bedplate roll-out shall be precluded when the transporter is in motion. Rationale: This 
assumption is used to prevent unfolding of scenarios where the WP carried by the transporter can 
be ejected out of the shielded compartment. The evaluation performed in Section 6.3.6.1.12 
shows that this requirement is achievable, for example, by using protection signals. 
5.1.7.7 No WP Breach in Case of Derailment or Collision Involving Transporter and 
Causing a Tipover 
Assumption: A design requirement will ensure that the WP transporter transports the WP in a 
manner such that if a collision or derailment leading to a transporter tipover occurs, the WP 
impact energy will be low enough to preclude a WP breach. Rationale: This assumption is 
needed to limit the severity of tipover events in which the WP transporter might be involved. 
The WP transporter may be designed such that in case of a collision or derailment resulting in a 
tipover, the maximum drop height of the WP will be limited to allowable heights.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 64 April 2005 
5.1.8 Assumptions Related to the WP Emplacement Gantry, Drip Shield Emplacement 
Gantry, and Emplacement Drifts 
5.1.8.1 Drop rate for WP Emplacement Gantry 
Assumption: Design and operational requirements on the WP Emplacement Gantry will ensure 
that the drop rate is less than or equal to 10-5 drops/transfer. Handling incidents are included 
regardless of cause; they may be caused by equipment failure, human error, or some combination 
of the two. Rationale: No operating experience of the emplacement gantry is available at this 
time. However, the emplacement gantry can be made by design as reliable as the cranes that 
handle waste forms, for which a failure rate of 10-5 drops/transfer is used, based on Assumption 
5.1.1.10. 
5.1.8.2 Average Exposure Time for WP Transit from Transporter Bedplate to 
Emplacement Drift Entrance 
Assumption: An operating requirement will ensure that the average exposure time of a WP 
transiting from the rolled out bedplate to the entrance of the emplacement drift does not exceed 4 
hours. Rationale: This assumption is required to ensure that the event sequence where rockfalls 
in the emplacement drift turnouts cause the structural failure of the WP can be rendered Beyond 
Category 2. The value of 4 hours is supported by Attachment II. 
5.1.8.3 Protection Against WP Emplacement Gantry Running Off the End of 
Emplacement Drift or Transfer Dock Rails 
Assumption: A design requirement will ensure that the WP Emplacement Gantry, carrying a 
WP, is not capable of running off the end of the emplacement drift or transfer dock rails. 
Rationale: This assumption is needed to preclude scenarios that could challenge the structural 
integrity of the WP and result in a Category 1 or Category 2 event sequence. The analysis 
performed in Sections 6.3.6.1.16 and 6.3.6.1.17 shows that this requirement is achievable. 
5.1.8.4 Not used 
5.1.8.5 Not used 
5.1.8.6 No WP Breach Following WP Emplacement Gantry Falling on Transporter 
Assumption: Design and operational requirements will ensure that if the gantry were to fall on 
the transporter and impact the WP, it would not cause the WP to be breached. Rationale: This 
requirement is achievable because the shape of the gantry prevents it from breaching the WP. 
The gantry features a hollowed-out space big enough to surround the WP in order to lift it. The 
lift hooks that engage under the pallet overhangs ensure that the WP is properly positioned inside 
that hollowed-out space. The distance between the overhangs and the bottom of the pallet is 
around 46 cm (BSC 2003 [DIRS 165731]). Therefore, the drop height of the gantry will be less 
than this distance. A gantry falling on the transporter bedplate is not likely to impact the WP; if 
it does, the impact will not be enough to jeopardize its structural integrity.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 65 April 2005 
5.1.8.7 Prevention of WP Breach Due to Collisions Involving the WP Emplacement 
Gantry 
Assumption: A design requirement will ensure that the WP Emplacement Gantry will be 
limited in speed such that it cannot cause a waste-package breach in case of a collision. The 
maximum allowable speed of the gantry is 15 mph. Rationale: The maximum speed is based 
on Anderson (2005 [DIRS 172857]). The requirement is achievable because passive features can 
be used to limit speed. 
5.1.8.8 Not used 
5.1.8.9 Not used 
5.1.8.10 Probability of Exceeding the WP Emplacement Gantry lift height limit 
Assumption: Design and operational requirements for the WP Emplacement Gantry will ensure 
that the conditional probability of having exceeded the WP lift height limit given that a drop 
occurred, is 10-4 or less. Rationale: Where the lift height limit is credited in the analysis, this 
assumption is needed to calculate the number of drops in excess of the height limit. Stating the 
design requirement in this way allows for the possibility that exceeding the height limit and 
dropping a WP are not statistically independent. The requirement is achievable because passive 
safety features on the WP Emplacement Gantry and procedural controls can be used to drive the 
conditional probability into the required range. 
5.1.9 Assumptions Related to the Transportation Cask Receipt and Return Facility 
(TCRRF) 
5.1.9.1 Lift-Height Limits for Transportation Casks With Impact Limiters and 
Transfer Casks With Impact Limiters 
Assumption: A design requirement will ensure that cranes for lifting transportation casks with 
impact limiters and transfer casks with impact limiters are not capable of lifting a cask more than 
30 ft (9 m) above the floor. Rationale: Transportation casks with impact limiters are designed 
and tested to withstand, without breaching, a 30-ft drop onto an unyielding surface (Section 
4.2.1). Transfer casks are similar to transportation casks (BSC 2005 [DIRS 171161] Section 
4.1.1.2). This assumption is needed to preclude Category 1 or Category 2 event sequences that 
breach DOE SNF canisters that may be inside the cask. The requirement is achievable because 
there is no operational need to lift casks higher than 30 ft. 
5.1.10 Assumptions Related to Construction 
5.1.10.1 Isolation of Construction and Operations 
Assumption: Operational requirements will ensure that construction operations are sufficiently 
isolated from surface and subsurface repository operations to preclude interactions with waste 
receipt, handling, emplacement, or retrieval operations. Rationale: This assumption is needed 
to prevent potential hazards that are not considered in detail in this analysis. The requirements
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 66 April 2005 
are achievable because it is common practice to isolate construction activities for the protection 
of other activities nearby.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 67 April 2005 
5.2 ASSUMPTIONS THAT ESTABLISH INPUTS 
5.2.1 General Assumptions 
5.2.1.1 Number of Times Each Individual Fuel Assembly Is Transferred in the DTF or 
FHF 
Assumption: Each CSNF assembly is transferred up to four times. Rationale: An assembly 
could be transferred as many as four times as follows: 
1. From the transportation cask and placed in a staging rack in the shielded waste transfer 
cell 
2. From the staging rack to an MSC to be aged in the SNF Aging System 
3. After aging, from the MSC to a staging rack in the shielded waste transfer cell; and, 
finally 
4. From the staging rack to a WP. 
The FHF has no staging racks, but assemblies may be staged in MSCs, so the number of 
transfers there is limited to two. In the DTF, one or both of the trips to the staging rack or the 
trip to the SNF Aging System could be skipped, resulting in anywhere from one to three transfers 
per assembly. To avoid placing restrictions on operations in the DTF, four transfers per 
assembly are assumed. This is a conservative assumption that bounds the actual number of 
transfers per CSNF assembly. 
5.2.1.2 Average Number of Times a DOE, Naval, or DPC Canister is Transferred 
Assumption: Canisters, including DOE, naval, and DPC canisters, are transferred an average of 
two times. Rationale: With both staging and aging, DOE canisters, like CSNF assemblies 
(Assumption 5.2.1.1), could be transferred up to four times. However, thermal management is 
not required for DOE canisters, so aging is not required. HLW canisters, which come five to a 
cask (Assumption 5.2.1.13), presumably will normally be transferred directly to a WP, which 
also holds five canisters (Section 4.1.1). Staging will often, but not always, be required for 
standardized DOE SNF canisters because each codisposal waste package can only hold one 
standardized canister. Neither MCOs nor naval canisters will be staged (Assumption 5.2.1.20). 
Therefore, it is conservative to assume that each DOE canister will go to a staging rack, which 
makes two transfers for each DOE canister. In the usual case, DPCs are transferred once in the 
DTF (from the cask to the cutting station) and again after being cut open. In the less common 
case, DPCs may be handled initially in the CHF or FHF. In that case, they will undergo an 
additional transfer (to an MSC before being sent to the aging pad). Therefore, the average 
number of transfers will be close to two for DPCs. The assumption is conservative for naval 
canisters and MCOs because they will not be staged or aged (Assumption 5.2.1.20). Assuming 
an average of two transfers per canister is more accurate than assuming four transfers, but still 
conservative.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 68 April 2005 
5.2.1.3 Number of CSNF Assemblies Breached By Drops and Collisions of Individual 
Assemblies 
Assumption: Two assemblies are breached by an assembly drop; one assembly is breached by 
an assembly collision. Rationale: A collision would affect the assembly being moved and the 
other object involved in the collision. Because only one assembly is moved at a time in a given 
waste transfer cell, only one assembly would be affected by a collision. For the event sequences 
initiated by dropping an assembly, the location of the drop determines the number of assemblies 
affected. If the drop occurs over the waste transfer cell floor, only one assembly would be 
affected. A drop into a cask, WP, or staging rack could affect one or more assemblies. One 
assembly would be affected if the assembly location of the drop were into an empty basket 
position. Two assemblies could be affected if the location of the drop were a basket position that 
is occupied by another assembly. This assumption requires further verification (TBV-7105). 
5.2.1.4 Inventory of CSNF Assemblies 
Assumption: The number of CSNF assemblies received over the lifetime of the repository is 
assumed to be 221,000. Rationale: The assumed number is rounded up from the number 
calculated from the information in Section 4.1.1 as presented in Table 5 (220,810). 
Table 5. Number of CSNF Assemblies 
WP Configuration 
Number of 
Assemblies Per WP Number of WPs 
Number of 
Assemblies 
21 PWR Absorber Plate 21 4,299 90,279 
21 PWR Control Rod 21 95 1,995 
12 PWR Absorber Plate Long 12 163 1,956 
44 BWR Absorber Plate 44 2,831 124,564 
24 BWR Absorber Plate 24 84 2,016 
Sum 220,810 
NOTE: Column 4 is calculated as the product of Columns 2 and 3. 
5.2.1.5 Inventory of DOE SNF canisters 
Assumption: The number of standardized DOE SNF canisters received over the lifetime of the 
repository is nominally 3,203. Rationale: This number is derived as follows from Section 4.1.1. 
Each of the DOE SNF WP configurations, except the MCO configuration, contains a single DOE 
SNF canister. Leaving out the MCOs, there are 1,403 that contain five short HLW canisters and 
one short standardized DOE SNF canister, 1,608 that contain five long HLW canisters and one 
long standardized DOE SNF canister, and 192 that contain three long HLW canisters and one 
standardized wide DOE SNF canister, for a total of 3,203 standardized DOE SNF canisters. 
5.2.1.6 Receipt of DOE MCO canisters 
Assumption: The number of DOE MCO canisters received over the lifetime of the repository is 
nominally 404. Rationale: This assumption is derived as follows from Section 4.1.1. There are 
nominally 202 MCO WPs, each containing two MCOs, for a total of 404 MCOs.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 69 April 2005 
5.2.1.7 Receipt of CSNF casks 
Assumption: The number of CSNF cask shipments received is nominally 9,508; these are 
divided among bare CSNF assembly shipments and DPC shipments with one DPC per cask. 
Rationale: This number is the sum from 2002 Operational Waste Stream Assumptions (BSC 
2002 [DIRS 162182], Table 5-2) of the number of CSNF truck shipments, 2,271; the number of 
bare CSNF rail shipments, 6,768; and the number of DPC rail shipments, 469. 
5.2.1.8 Receipt of HLW Canisters 
Assumption: The total number of HLW canisters received over the lifetime of the repository is 
nominally 16,070. Rationale: This assumption is derived as follows from Section 4.1.1. There 
are 1,403 waste packages that each contain five short HLW canisters and one short standardized 
DOE SNF canister, 1,608 that contain five long HLW canisters and one long standardized DOE 
SNF canister, 192 that contain three long HLW canisters and one standardized wide DOE SNF 
canister, 7 that contain five HLW canisters and no DOE SNF canisters, and 202 that contain two 
HLW canisters and two MCOs. This gives 16,070 HLW canisters. 
5.2.1.9 Receipt of Naval SNF Canisters 
Assumption: The total number of naval SNF canisters received over the lifetime of the 
repository is nominally assumed to be 300. Rationale: This number is the sum of 144 short 
naval WPs plus 156 long naval WPs, each of which contains one naval canister (Section 4.1.1). 
5.2.1.10 Receipt of Transportation Casks 
Assumption: The number of transportation-cask receipts is assumed to be 13,479. Rationale: 
This number is the sum of the numbers of casks from the various types as presented in Section 
6.3. The number bounds 12,041, which is given in 2002 Operational Waste Stream Assumptions 
(BSC 2002 [DIRS 162182], Table 5-2). 
5.2.1.11 One Assembly Breached by Dropped Handling Equipment from the Spent Fuel 
Transfer Machine 
Assumption: A drop of handling equipment from a spent fuel transfer machine or fuel handling 
machine would not breach more than one CSNF assembly. Rationale: The grapples on the 
spent fuel transfer machine and fuel handling machine are not massive structures that could 
breach more than one assembly. In fact, the damage done to the assembly affected by a drop 
would probably be less than would occur from a drop of the assembly itself. 
5.2.1.12 Not used.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 70 April 2005 
5.2.1.13 Capacities of Transportation Casks for Naval SNF and DOE Owned Waste 
Assumption: Capacities of rail-based transportation casks for DOE owned waste are assumed as 
follows: 
 HLW canisters 5 canisters shipped together per cask 
 Standardized DOE SNF canisters: 9 canisters shipped together per cask 
 DOE MCO canisters 4 canisters shipped together per cask 
 Naval canisters 1 per cask 
Rationale: These are the assumptions made for transportation casks in 2002 Operational Waste 
Stream Assumptions (BSC 2002 [DIRS 162182], Section 4.2). The capacities for DOE waste are 
different for truck and rail casks. Because rail is expected to be the dominant mode of 
transportation to the repository, this assumption pertains to rail-based casks. If truck casks are 
used, the capacities would be smaller and the required number of shipments greater. The 
uncertainty in the capacity of transportation casks is not addressed directly but is addressed by 
the factor of conservatism presented in Section 6.1.4. 
5.2.1.14 Fraction of Fuel Assemblies Requiring Individual Canisterization 
Assumption: No more than 1 percent of bare fuel assemblies will arrive so severely damaged 
that they must be canisterized. Rationale: Because the categorization results (Section 6.3.1.15) 
are insensitive to the precise value of this number, it is adequate for its intended purpose. 
5.2.1.15 Not used 
5.2.1.16 Not used 
5.2.1.17 Not used 
5.2.1.18 Not used 
5.2.1.19 Criticality Safety for HLW Canisters 
Assumption: The fissile content of HLW canisters is such that there is no potential for 
criticality. Rationale: HLW is the waste product from processes that remove fissile components 
from spent nuclear fuel. Therefore, HLW canisters do not contain sufficient quantities of fissile 
material to pose a risk of criticality. 
5.2.1.20 Staging and Aging of Canisters 
Assumption: Neither naval canisters nor MCOs will be staged in staging racks or MSCs or 
placed on the aging pads. They will be transferred directly from a transportation cask into a WP. 
The analysis assumes that standardized DOE SNF canisters and HLW canisters may be staged at 
an aging pad. Rationale: Staging of the naval canister is not needed because there is one
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 71 April 2005 
canister per cask and one canister per WP. Thermal management does not require aging of DOE 
MCO canisters. Although thermal management is not required for standardized DOE SNF 
canisters or HLW canisters, they may occasionally be staged on aging pads for throughput 
management.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 72 April 2005 
5.2.2 Assumptions Related to External Hazards 
5.2.2.1 Frequency of Loss of Offsite Power 
Assumption: Loss of offsite power occurs at a frequency of 0.1 time per year. Rationale: This 
assumption is needed for estimating the availability of the HVAC system in the primary and 
secondary confinement areas of the DTF and FHF. This frequency value is based on the 
following assessment. 
EPRI (2002 [DIRS 168640], p. 1-2) analyzed the operating experience for losses of offsite power 
at U.S. nuclear power plants over the 1990 through 2001 period and gives a range of 0.03 to 0.04 
loss per generating unit year. More precisely, a best estimate value of 0.031 loss per generating 
unit year (national average) is found (EPRI 2002 [DIRS 168640], p. 1-1). This frequency 
accounts for a true unavailability of offsite power, which means that no alternate offsite source of 
power is available. 
Other events occur at nuclear power plants that are in some way related to loss of offsite power. 
These events are also considered by EPRI (2002 [DIRS 168640], p. 2-3) and include: 
1. Loss of offsite power but the main generator remains connected and the plant receives 
power from the unit transformer. This class of event should also be counted in the 
frequency of total loss of offsite power at the repository (since the function of the 
repository is not to generate its own energy). The corresponding frequency is 
evaluated at 0.013 loss per generating unit year (EPRI 2002 [DIRS 168640], Table 2- 
5). 
2. Unit trips but offsite power remains available. These events are not relevant to the 
repository. 
3. Off-site power loss occurs during cold shutdown as a result of shutdown testing and 
maintenance operations that are not representative of what would occur during normal 
operations (i.e., when the unit generates power). This class of event is not relevant to 
the repository. 
Therefore, the total frequency of loss of offsite power, resulting from events applicable to the 
repository, does not exceed 0.031 + 0.013 = 0.044 losses per generating unit year. 
A greater frequency of loss of offsite power equal to 0.1 loss per year is assumed for the 
repository. The reason for this is that the frequency of 0.044 loss per generating unit year found 
previously accounts for outages due to weather conditions typical of the eastern seaboard, that 
are not expected in the area near the repository. In Table 2-9 of EPRI (2002 [DIRS 168640]), 13 
weather-related losses of offsite power occurred in 1271.2 generating unit years, which translates 
in a frequency of 0.01 loss per generating unit year. Of these 13 events, 4 lasted more than 4 
hours and occurred at plants on the eastern seaboard (EPRI 2002 [DIRS 168640], p. 2-18). This 
means that in the total frequency of 0.044 loss per generating unit year, the contributive 
frequency of 4/1271.2=0.003 loss per generating year is not relevant for the repository. This 
yields an adjusted frequency of 0.044-0.003=0.041 loss per generating unit year. The frequency 
of 0.1 loss per year used for the repository is more than 2.4 times greater than this value.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 73 April 2005 
Further information on the frequency of loss of offsite power is found in NUREG-1784 
(Raughley and Lanik 2003 [DIRS 172451]). In that study, loss of offsite power events at U.S. 
nuclear power plants are not defined in the same way as in the EPRI report. Events that involve 
a degradation of the grid condition, including plant-centered conditions such as a turbine trip 
resulting in the plant disconnecting from the grid and a grid voltage decrease, are considered as 
grid-related loss of offsite power events (Raughley and Lanik 2003 [DIRS 172451], p. 10). 
Also, events that do not result in a reactor trip are not considered as loss of offsite power events 
(Raughley and Lanik 2003 [DIRS 172451], p. 10). Finally, the operating experience gained from 
U.S. nuclear power plants is investigated for two phases: from 1994 to 1996 (period before 
deregulation of the electrical industry), and from 1997 to 2001 (period after deregulation of the 
electrical industry). For all these reasons, the calculated frequency of loss of offsite power is not 
the same as that of the EPRI report. Namely, a frequency of 0.05 loss of offsite power per 
reactor year is found for the period 1994 to 1996, and a frequency of 0.014 loss of offsite power 
per reactor year is found for the period 1997 to 2001 (Raughley and Lanik 2003 [DIRS 172451], 
Table 2). In comparison, the value of 0.1 loss of offsite power per year used at the repository is 
greater by a factor 2 and a factor 7.1 respectively. 
It is recognized that the repository is not a nuclear power plant. Therefore, the frequencies of 
loss of offsite power obtained from operating experience at U.S. nuclear power plants are not 
directly applicable to the repository. Nonetheless, based on the previous assessment, it can be 
concluded that the frequency of 0.1 loss of offsite power per year is achievable. It is expected 
that the grid at the repository will have such a reliability. This assumption, however, needs to be 
verified (TBV-7100). 
5.2.3 Assumptions Related to Remediation 
5.2.3.1 Fraction of Waste Forms Subject to Dry Remediation 
Assumption: No more than 10 percent of the SNF and HLW to be emplaced is subject to dry 
remediation. Rationale: This assumption is needed to assess drops and collisions of CSNF 
assemblies in the DPC cutting/WP dry remediation cell. The normal process of DPC cutting is 
not covered by this assumption. The handling of CSNF assemblies in the DPC cutting/WP dry 
remediation cell is not a normal part of the processing stream. Waste may be transferred from 
defective, damaged, or otherwise suspect MSCs, casks, or WPs. Only a small fraction of the 
waste to be emplaced requires remediation. A 10 percent rate of defective, damaged, or 
otherwise suspect casks or WPs would be considered unacceptable with respect to operational 
safety. If such a rate were experienced, it is reasonable to believe that design or operational 
changes would be implemented to reduce the fraction processed through the dry remediation area 
to below 10 percent. Therefore, 10 percent is a bounding fraction for the categorization 
calculations. 
5.2.3.2 Fraction of Waste Forms Handled in the DTF Cask Wet Remediation/Laydown 
Area 
Assumption: No more than 10 percent of the waste inventory is handled in the cask wet 
remediation/laydown area. For casks, 10 percent of the total number of transportation cask 
receipts and an equal number of MSCs will be handled. Rationale: Remediation is not a normal
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 74 April 2005 
part of the processing stream. It is reasonable to suppose that a 10 percent remediation rate 
would be viewed as unacceptable and that the processing operations would be investigated and 
improved to reduce the remediation rate. Therefore, 10 percent is a bounding fraction for the 
categorization calculations. 
5.2.3.3 Capacity of CSNF Assembly Basket in the Remediation Pool 
Assumption: The capacity of the CSNF assembly basket in the remediation pool will be sixteen 
BWR assemblies or nine PWR assemblies. Rationale: The baskets are designed to hold the 
stated numbers of assemblies per basket (Cogema 2003 [DIRS 167153]). For the calculations 
that determine the category of the event sequences, CSNF assemblies are treated generically. 
The lower number is conservative for categorization because it implies a greater number of 
basket movements. The higher number is conservative when stating material at risk because it 
provides a higher source term. 
5.2.3.4 Number of Crane Transfers Required After WP Closure To Transfer a WP to 
the DPC Cutting/WP Dry Remediation Cell and Then to the Transfer Trolley 
Assumption: Three crane transfers are assumed to be required after welding to transfer a WP to 
the DPC cutting/WP remediation cell and, after cutting, to the trolley. Rationale: This number 
is consistent with the internal hazards analysis (BSC 2005 [DIRS 171428], Section 6.6.3.12).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 75 April 2005 
5.2.4 Assumptions Related to the SNF Aging System 
5.2.4.1 MSC Capacities are Similar to Transportation Cask Capacities 
Assumption: It is assumed that MSCs may be loaded with up to five HLW canisters and that 
the CSNF capacities of MSCs and transportation casks are approximately the same, on average. 
Rationale: MSCs hold approximately 10 MTHM of spent fuel (1,000 MTHM per unit divided 
by 80+20=100 casks per unit [BSC 2004 {DIRS 171161}, Section 4.1.1.1]). The primary 
purpose of MSCs is to age CSNF. CSNF transportation casks hold on average 63,000 MTHM 
(Section 4.3.1) divided by 9,508 casks (Table 8), that is, about 7 MTHM. Thus, the capacity of 
MSCs is similar to that of transportation casks. Transportation casks are assumed to hold five 
HLW canisters (Assumption 5.2.1.13). 
5.2.5 Assumptions Related to the WP Transporter 
5.2.5.1 Human Error Probability for Premature Actuation of Bedplate Rollout 
Mechanism or Premature Transporter Departure 
Assumption: The probability of the operator attempting to prematurely actuate the bedplate 
rollout mechanism is estimated at 0.01. The same value is used for the probability of the 
operator prematurely ordering the transporter to depart the emplacement drift transfer dock. 
Rationale: This human error probability value is based on the estimate provided by Swain and 
Guttmann (1983 [DIRS 139383], Table 20-6), to characterize the failure to use written operation 
procedures under normal operating conditions. The operator prematurely actuating the bedplate 
rollout mechanism or transporter departure are represented by the human error failure to use a 
written procedure, because the proper conduct of WP transporter operations will be described in 
a procedure that the operator will be required to follow. However, the transporter operations will 
also be monitored and controlled by the digital control and management information system 
(BSC 2004 [DIRS 171251], Table 2). Therefore, the operator will not have the latitude to 
initiate actions that could fall outside of the framework of normal operations, as easily as he or 
she could if only written procedures were used. Thus, the 0.01 probability considered in this 
assumption is conservative. As mentioned in Swain and Guttmann (1983 [DIRS 139383], p. 2- 
18), the probabilities given for human errors represent median values of lognormal distributions. 
No conversion to the mean was done. This is because such a conversion would yield a 
probability value greater than 0.01. Making an adjustment to the mean is not useful for the 
preliminary scoping calculations performed in this analysis because the 0.01 probability value is 
already conservative. 
5.2.5.2 Failure Rate of a Process Switch 
Assumption: The spurious operation rate of a process switch used to control WP transport 
operations in the subsurface facilities is assumed to be in the order of magnitude of 10-6 per hour. 
Rationale: This failure rate is based on the compilation by Eide and Calley (1993 [DIRS 
146564], Table 2), which gathers a database of generic failure rates developed for light water 
reactor probabilistic risk assessments (Eide and Calley (1993 [DIRS 146564], Abstract). The 
controlled environment of nuclear power plants is deemed comparable to the conditions under 
which the transport operations of the WP will be carried out, thus the 10-6 order of magnitude for
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 76 April 2005 
the hourly failure rate of the process switch is considered to be adequate for use in the present 
calculation. 
5.2.5.3 Failure Probability of a Speed Transducer 
Assumption: The failure probability of a speed transducer used on the transporter carrying a WP 
is in the 10-5 order of magnitude. Rationale: Based on Eide and Calley (1993 [DIRS 146564], 
Table 2), the failure rate for a speed transducer is 1.0  10-6 per hour. This failure rate, which 
was initially developed for performing probabilistic risk assessments of nuclear power plants, is 
appropriate for evaluating the reliability of components operating in a strictly controlled 
environment such as that in which the WP transport operations will be performed. Based on that 
hourly failure rate, the failure probability of the speed transducer is estimated. To do that, it is 
necessary to know the mission time of the speed transducer. The architecture of the control 
system of the WP transporter is not known at this time, but it is reasonable to expect that the 
failure of a speed transducer could be identified. Therefore, the mission time for a speed 
transducer can be taken as the time during which the transporter carrying a WP travels 
underground. The time spent underground is conservatively estimated at six hours (BSC 2004 
[DIRS 168508], Section 6.3.1). Consequently, the failure probability of a speed transducer can 
be evaluated at 6 h  1.0  10-6 per h = 6.0  10-6. Therefore, the 10-5 order of magnitude of this 
assumption is acceptable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 77 April 2005 
5.2.6 Assumptions Related to the Emplacement Gantry and Emplacement Drifts 
5.2.6.1 Human Error Probability for Inadvertently Ordering the Gantry Carrying the 
WP Back to the Emplacement Drift Transfer Dock 
Assumption: The probability of the operator inadvertently ordering the emplacement gantry 
carrying the WP back to the emplacement drift transfer dock is estimated at 0.01. Rationale: 
This human error probability value is the same as that used in Assumption 5.2.5.1, and is based 
on the probability of failing to follow a written procedure. The probability of an inadvertent 
actuation of a control may be more appropriately described by the operator selecting a wrong 
control on a panel from an array of similar-appearing controls, which Swain and Guttmann (1983 
[DIRS 139383], Table 20-12) assign a nominal probability of at most 0.003. Nevertheless, the 
0.01 value was kept in the present assessment because it is used for a scoping evaluation and 
because it provides some conservatism. 
5.2.6.2 Human Error Probability for Sending Improper Order to the Gantry 
Assumption: The probability of the operator improperly ordering the gantry carrying the WP to 
go past the designated emplacement location of the WP is estimated at 0.01. Rationale: The 
rationale for this probability estimate is similar to that of Section 5.2.5.1. The operator error is 
represented by the failure to use a written procedure under normal operating conditions, which 
has a probability of 0.01 (Swain and Guttmann 1983 [DIRS 139383], Table 20-6).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 78 April 2005 
6 ANALYSIS 
6.1 METHODS 
6.1.1 Categorization Methods 
6.1.1.1 Categorization of Event Sequences Based on Expected Number of Occurrences 
Some event sequences may be categorized without considering the time span during which the 
event sequence may occur. Consider, for example, dropping an individual spent fuel assembly 
during a transfer from one container to another. To decide whether the event sequence meets the 
definition of Category 1 (Section 1), it is necessary to know whether one or more drops during 
the preclosure period of the repository are expected. If the expected number of drops per transfer 
is fixed and the number of transfers required is known, then the expected number of drops over 
the lifetime of the repository may be calculated without knowing the duration of operations. To 
be more precise, assume that x assemblies are to be accepted for disposal, the number of times 
each assembly must be transferred is y transfers/assembly, and the drop rate is z drops/transfer, 
then the total number of transfers is xy and the expected number of drops for the lifetime of the 
repository is xyz drops. If xyz = 1 the event is Category 1. 
An event sequence that is not Category 1 may be Category 2. However, the definition of 
Category 2 (Section 1) depends on the probability of one or more events during the lifetime of 
the facility rather than the expected number of events. For example, the probability of dropping 
an assembly during a single transfer is equal to the expected number of drops per lift, z. 
Therefore, the probability that no drop occurs during a single transfer is 1 - z. If each drop is 
independent of other drops, the probability that there are no drops for xy transfers (the total 
expected during the life of the facility) is (1 - z)xy. Finally, the probability that there are one or 
more drops during the life of the facility is 1 - (1 - z)xy. An application of lHospitals rule 
(Mood et al. 1974 [DIRS 122506], Appendix A, Section 3.1) shows that the probability 
1 - (1 - z)xy is approximately equal to the expected number of drops, xyz, when z << 1. To show 
the approximate equality, apply lHospitals rule as follows. 
. 1 
) 1 ( 
lim 
] ) 1 ( 1 [ 
d
d 
) ( 
d
d 
lim 
) 1 ( 1 
lim 
1 0 
0 0 
= 
- 
= 
- - 
= 
- - 
- . 
. . 
xy z 
xy z xy z 
z xy 
xy 
z 
z 
xyz 
z 
z 
xyz
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 79 April 2005 
Therefore, the following rules are used to categorize event sequences (M is the expected number 
of occurrences of an event sequence before permanent closure of the repository): 
M = 1 Category 1 
10-4 = M < 1 Category 2 
M < 10-4 Beyond Category 2. 
In some cases, the expected number of occurrences of an event sequence is so low that the event 
sequence may be said to be prevented or precluded, without specifying or calculating an 
expected number of occurrences. A numerical interpretation of such claims is that the expected 
number of occurrences over the operational life of the facility is much less than 10-4. 
6.1.1.2 Categorization of Event Sequences Based on Frequency of Occurrence 
For some events, it is convenient to categorize based on annual frequency of occurrence. An 
example is the possibility of accidental aircraft crash into the surface facility. The longer the 
surface facility operates, the longer the exposure time, and the greater the likelihood of a crash. 
For a given annual crash frequency, the probability of a crash is proportional to the duration of 
surface operations. In such cases, the annual frequency of occurrence is compared to threshold 
frequencies derived from the definitions of Categories 1 and 2. The frequency thresholds for 
Categories 1 and 2 depend on the applicable time spans for the potentially affected activities 
(Table 6). 
Table 6. Frequency Thresholds for Categories 1 and 2 
When Event Sequence 
May Occur 
Applicable 
Time Span 
(y) 
Applicable 
Category 1 
Frequency 
Threshold 
(y-1) 
Applicable 
Category 2 
Frequency 
Threshold 
(y-1) 
Only during emplacement 
operations 50 2  10-2 2  10-6 
Any time before permanent 
closure 100 1  10-2 1  10-6 
NOTE: The Category 1 thresholds are calculated as 1 event divided by the applicable time span. The 
Category 2 thresholds are calculated as 1/10,000 divided by the applicable time span. See 
Assumption 5.1.1.65 for applicable time spans. 
6.1.2 Methods for Estimating Frequencies 
Annual frequencies of Category 1 event sequences are needed as inputs to analyses that will 
assess the frequency-weighted radiological consequences and the normal operating doses. To 
comply with 10 CFR 63.21(c)(5) [DIRS 158535], annual frequencies of Category 1 event 
sequences are estimated at the maximum anticipated rate of receipt of radioactive waste. 
Calculations to ensure that normal operating doses are as low as reasonably achievable also 
require frequencies for Category 1 event sequences. Annual frequencies of Category 2 event 
sequences are not calculated.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 80 April 2005 
6.1.3 Methods for Estimating the Amounts of Material at Risk 
This analysis does not estimate radiological consequences of event sequences. However, it does 
estimate the quantity of SNF or HLW that is available to produce radiological consequences as 
the result of an event sequence. This quantity is called the amount of material at risk. The 
amount of material at risk is stated in terms of numbers of CSNF assemblies, HLW canisters, 
naval SNF canisters, or DOE SNF canisters. The amount of material at risk is an output of this 
analysis and feeds the consequence analyses. Consideration of the source terms that correspond 
to the material at risk is beyond the scope of this analysis. 
6.1.4 Treatment of Uncertainty 
Uncertainties in categorization and frequency estimation are addressed by using conservative 
inputs and a factor of conservatism of 1.1 for the categorization calculations. For example, the 
expected number of canister drops from cranes depends directly on the number of canisters 
transferred, the number of times each canister is transferred, and the drop rate per transfer. The 
number of canisters handled is taken to be the nominal number to be handled. The number of 
times each canister is transferred is conservatively taken to be the maximum reasonable number 
of transfers. That is, whenever there is a reasonable opportunity for staging or aging, it is used. 
Thus, the minimum case involving the transfer of a canister from a transportation cask directly to 
a WP requires only one transfer. The maximum reasonable case allows for (1) a transfer to 
staging, (2) a transfer to an MSC, (3) after the aging period, a transfer to a staging rack, and, 
finally, (4) a transfer to the WP. Unreasonable opportunities for staging or aging, such as 
repeated transfers to and from staging areas and repeated trips to the aging pads, are not used. 
Taking the maximum reasonable number of transfers (four) as opposed to the minimum number 
(one) is conservative by up to a factor of 4, depending on operational details that eventually 
emerge. The maximum drop rates are specified as design requirements. Conservatism in the 
categorization calculations ensures that discrepancies, if any, between the categorization 
calculations and what would be observed in reality would result in improperly assigning 
Category 1 when Category 2 should apply, or Category 2 when Beyond Category 2 should apply. 
Uncertainties in the outcomes of event sequences are addressed by using the worst outcome for 
each event sequence. Conservatism is used throughout the analysis to ensure that estimates of 
the outcomes of event sequences overstate the amount of material at risk.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 81 April 2005 
6.2 CATEGORIZATION OF EXTERNAL EVENT SEQUENCES 
The following hazards are applicable to the Yucca Mountain repository (Section 4.1.4). 
 Aircraft crash 
 Rainstorm and flooding 
 Range fire 
 Loss of offsite or onsite power 
 Nearby industrial or military activities 
 Seismic activity 
 Tornado or extreme wind 
 Lightning 
 Ash fall due to volcanism 
 Drift degradation 
 Extreme weather (temperature) fluctuation 
 Sandstorm 
The strategy for categorization of event sequences initiated by external hazards is to demonstrate 
that at least one of the following is true: 
 The event frequency is Beyond Category 2 
 Engineered features of the repository that are needed to meet the performance objectives 
in 10 CFR 63.111 [DIRS 158535] can withstand the event 
 Protection is provided against reasonable initiating events consistent with precedents 
adopted for nuclear facilities with comparable or higher risks (in accordance with 10 
CFR 63.102(f) [DIRS 158535]). 
This strategy ensures that external events do not initiate Category 1 or Category 2 event 
sequences that exceed the performance objectives of 10 CFR Part 63 [DIRS 158535]. 
6.2.1 Aircraft Crash 
An event sequence initiated by aircraft crash is Beyond Category 2 provided operational and 
design requirements credited in the crash frequency analysis are observed (Section 4.1.12). 
6.2.2 Rainstorm and Flooding 
Rainstorm has been identified as a potential external hazard (BSC 2004 [DIRS 167266], Section 
6.4.34). Consistent with regulatory precedent, initiation of event sequences due to precipitation 
(including rainstorm) during the preclosure period is prevented by compliance with design 
criteria that specify reasonable maximum annual, daily, and hourly precipitation rates that the 
repository is designed to withstand while operating (Section 4.3.2).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 82 April 2005 
6.2.3 Range Fire 
Compliance with regulatory requirements and adherence to fire protection codes and standards 
will ensure that range fires are mitigated before they pose a hazard that could involve a release of 
radioactive material (Section 4.1.15). Thus, consistent with regulatory precedent, range fire is 
screened out as an initiating event. 
6.2.4 Loss of Offsite or Onsite Power 
Surface facilities are designed such that a loss of offsite or onsite electrical power will not initiate 
an event sequence. This design and operational philosophy requires certain design features of 
the facilities and the equipment that require power from the offsite electrical grid for normal 
operation. To identify those requirements, this section reviews electrical equipment that may be 
relied upon to fulfill a safety function. 
6.2.4.1 Cranes, Gantries, Spent Fuel Transfer Machines, and Fuel Handling Machines 
Electrically powered cranes are used for lifting and transferring SNF and HLW in the TCRRF, 
the DTF, CHF, and the FHF. An electrically powered spent fuel transfer machine transfers 
CSNF assemblies in the FHF and dry transfer cell of the DTF. An electrically powered fuel 
handling machine transfers CSNF assemblies in the remediation pool. An electrically powered 
gantry is used for lifting and emplacing WPs in the emplacement drifts. To prevent the 
possibility of dropping a canister, CSNF assemblies, a WP, or a transportation cask upon loss of 
offsite power, cranes, gantries, spent fuel transfer machines, and fuel handling machines must be 
designed to stop and retain their loads upon loss of power (Assumption 5.1.2.1) 
6.2.4.2 Trolleys and Transporters 
Electrically powered trolleys are used for moving waste within the surface facilities, and an 
electrically powered transporter is used for moving WPs from the surface to the emplacement 
transfer dock. To prevent the possibility that a loss of offsite power could lead to dropping a 
canister, WP, or transportation cask from higher than its design basis drop height or to an 
uncontrolled glide ending in collision, trolleys and transporters must be designed to stop and 
retain their loads upon loss of power (Assumption 5.1.2.2). 
6.2.4.3 Instrumentation and Control Systems 
Much of the equipment to be used for handling and moving SNF and HLW, such as cranes, 
gantries, trolleys, and transporters, is remotely operated. To prevent the initiation of Category 1 
or Category 2 event sequences upon loss of power, the remotely operated equipment must be 
designed to fail safe upon loss of power such that the systems being controlled are left in a safe 
state (Assumption 5.1.2.1). To ensure the ability to restore safe operation after a loss of power, 
the equipment must stay in the locked mode until operator actions are taken during equipment 
restoration (Assumption 5.1.2.1).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 83 April 2005 
6.2.4.4 Monitoring Equipment 
Monitoring equipment is in operation throughout the facility to alert operators to Category 1 or 
Category 2 event sequences or abnormal conditions such as radiological releases, excessive 
radiation, and excessive temperatures. The failure of monitoring equipment upon loss of power 
may cause a failure to detect or monitor the consequences of a radiological release or exposure, 
but the failure cannot cause a release or exposure. Although monitoring equipment may help 
keep normal operating exposures as low as reasonably achievable, it is not relied upon to prevent 
or mitigate Category 1 or Category 2 event sequences. 
6.2.4.5 Lighting 
Electrical lighting is necessary for the normal operation and security of repository facilities. The 
failure of lighting upon loss of power may cause the operator to suspend normal operations, but 
it cannot initiate an event sequence or exposure. 
6.2.4.6 Electrically Controlled Seals 
Electrical power may be required to establish seals at the docking ports where transportation 
casks, MSCs, and WPs mate with the waste handling cells. Waste handling cells may also have 
other electrically controlled seals. However, even if a loss of power could lead to seal failure 
and a simultaneous loss of confinement ventilation, operational procedures will ensure that there 
is no potential to expose individuals to significant amounts of radioactivity (Assumption 
5.1.1.59). 
6.2.4.7 Heating, Ventilation, and Air-Conditioning 
6.2.4.7.1 Ambient Air Temperature Control 
6.2.4.7.1.1 Transportation Cask Receipt/Return Facility 
SNF and HLW is contained in transportation casks in the TCRRF. The transportation casks are 
designed to contain SNF without active cooling if the cask lid is not removed. Therefore, loss of 
HVAC will not cause the initiation of a Category 1 or Category 2 event sequence. 
6.2.4.7.1.2 Transportation Cask Staging Areas and the Aging Pads 
These areas are open-air facilities and are not provided with HVAC. Therefore, a loss of power 
that shuts down HVAC systems will not affect these areas.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 84 April 2005 
6.2.4.7.1.3 DTF 
In the cask and MSC receipt area of the DTF, SNF and HLW are contained in inerted 
transportation casks or canisters that are inerted with gases with high thermal conductivity. 
Similarly, WPs in the WP loadout cell, the WP transporter vestibule, and the exit vestibule, are 
sealed and inerted. Even if ventilation is lost in these areas, no radiological release will occur 
because containment within the cask or MSC is maintained. 
Other areas of the DTF include handling and staging areas for individual CSNF assemblies and 
canisters of HLW and SNF. If ventilation is lost in these areas, no radiological release will occur 
from canisters because containment within the canister is maintained. The design of the staging 
area for CSNF assemblies provides adequate passive cooling such that a loss of ventilation 
would not cause radiological releases in excess of those considered in the consequence analysis 
for normal operations (Assumptions 5.1.2.4 and 5.1.1.45). 
6.2.4.7.1.4 FHF 
The main transfer room, fuel transfer room, and preparation room of the FHF are designed and 
operated such that a loss of ventilation would not cause radiological releases in excess of those 
considered in the consequence analysis for normal operations (Assumptions 5.1.2.4 and 
5.1.1.45). 
6.2.4.7.1.5 CHF 
In the CHF, SNF is contained in sealed canisters that are inerted with gases with high thermal 
conductivity. HLW is contained in sealed canisters. Even if forced ventilation is lost in these 
areas, no radiological release will occur because containment within the canister is maintained. 
6.2.4.7.1.6 Central Control Center Facility and Control Areas 
Remote control of certain processes will be conducted from a Central Control Center Facility or 
from control areas in the various process buildings. If the HVAC system in the control areas of 
process buildings shuts down, workers may be forced to temporarily vacate these work areas if 
temperatures rise or fall excessively. However, the preclosure safety analysis does not take 
credit for human intervention from the control center or other control areas to prevent or mitigate 
Category 1 or Category 2 event sequences. 
6.2.4.7.1.7 Subsurface 
Underground ventilation could be lost due to a loss of offsite power. This would cause the 
temperature of the WP to increase. Provided that the WP temperature remains below 
temperatures that could jeopardize the structural integrity of the WP, there will be no radioactive 
release. A temperature of 300C is acceptable for the phase stability of the WP (BSC 2004 
[DIRS 169885], Table 9). Although much higher temperatures may be acceptable for short-term 
structural integrity, it is apparent that the WP will maintain structural integrity if the phase 
structure is unchanged. In a calculation that investigates the increases in temperature due to a 
loss of subsurface ventilation, it is shown that approximately seven years or more is required for 
the surface temperature of the waste package to reach 300C (BSC 2004 [DIRS 172176], Figure
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 85 April 2005 
6.3-3). Because it is reasonable to expect that forced ventilation can be restored in less than 
seven years, it can be concluded that a loss of subsurface ventilation will not cause a radioactive 
release. 
6.2.4.7.2 HVAC Confinement 
The loss of a confinement due to shutdown of the ventilation system will not initiate an event 
sequence, as explained in Section 6.3.1.25. 
6.2.4.8 Pool-Water Cooling and Make-up Water Systems 
A loss of offsite power could cause the pool-water cooling system and the make-up water system 
to shut down. With the cooling system shut down, decay heat from SNF in the pool would cause 
the pool temperature to rise. Given enough time, and no make-up water, evaporation of pool 
water could reduce the depth of the pool water. A reduction in the depth of pool water could 
pose an increased risk of radiation exposure to workers. 
Loss of pool cooling would occur if the recirculating cooling system became unavailable due to 
loss of power. An analysis was done to determine the time available to restore pool cooling 
before the pool water reached boiling temperature (BSC 2004 [DIRS 167860]). The analysis 
showed that at least 3,000 h (125 days) would be required to raise the pool water temperature to 
the boiling point after loss of cooling (BSC 2004 [DIRS 167860], p. 28). This analysis used 
several conservative assumptions, as follows: 
 Heat losses due to evaporation were not considered (maximum evaporative heat losses 
would remove 71 percent of the maximum decay heat load). 
 The decay heat load was assumed to be the maximum possible (all rack positions filled 
and fuel at maximum decay heat generation). 
 Heat losses due to conduction through walls and floor not considered. 
Before radioactive exposure could occur, the pool water would have to evaporate down 
significantly. It is concluded that ample time would be available to restore cooling to the pool, 
or makeup water, before the power loss would result in exposure of individuals to radiation. 
Therefore, an event sequence initiated in the pool by loss of power is Beyond Category 2. 
6.2.5 Nearby Industrial and Military Facilities 
There are no known military or industrial activities (existing or planned) that initiate event 
sequences with radiological consequences to offsite individuals or workers during the preclosure 
period (Section 4.1.4). See Section 6.2.1 for discussion of aircraft hazards. 
6.2.6 Seismic Activity 
Facilities will be designed such that seismic events will not initiate Category 1 or Category 2 
event sequences that lead to doses to workers or the public that exceed the performance 
objectives of 10 CFR 63.111 [DIRS 158535] or that lead to a criticality condition (Section
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 86 April 2005 
4.1.14, Assumption 5.1.1.37). The application of the seismic design bases precludes the 
occurrence of any seismically initiated event sequence having a mean annual probability of 10-3 
or greater and, therefore, precludes the occurrence of a Category 1 seismically initiated event 
sequence (BSC 2004 [DIRS 170564], Section 2.1). Seismically initiated event sequences that 
are mitigated or prevented by the use of a DBGM-1 assignment to a SSC are less probable than 
the Category 1 occurrence criterion (BSC 2004 [DIRS 171470], Section 6.1.1.); implicitly, such 
event sequences are Category 2. Similarly, a DBGM-2 assignment provides reasonable 
assurance in accordance with 10 CFR 63.102(f) [DIRS 158535] that the corresponding 
seismically initiated event sequences are Beyond Category 2 (BSC 2004 [DIRS 170564], Section 
3.3.2). Therefore, the seismically initiated event sequence of concern for the categorization 
analysis is the Category 2 event sequence involving the earthquake-induced failure of SSCs that 
are designed to DBGM-1. Because there is no regulatory dose limit for on-site personnel 
associated with Category 2 event sequences, only SSC failures with potential dose to the off-site 
public are of concern. The seismically initiated Category 2 event sequence of concern is 
described in Table 7.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 87 April 2005 
Table 7. Description of the Category 2 Seismic Event Sequence 
SSC Description of SSC Failure and Bounding Material at Risk 
Permanent shielding (CHF, 
DTF, FHF) 
N/Aa 
Cask pit protective cover 
(Cask Preparation) 
N/Aa 
WP pit protective cover (WP 
Preparation) 
N/Aa 
MSC pit protective cover (WP 
Preparation) 
N/Aa 
HLW canister Breach of HLW canisters due to earthquake would be Category 2 with a DBGM- 
1 classification (Section 4.1.14). Because HLW canisters as currently designed 
and fabricated are expected to be able to withstand a DBGM-2 earthquake 
without breach, the seismic classification is upgraded to DBGM-2. Therefore, a 
breach of HLW canisters due to a seismic event is Beyond Category 2. 
WP transporter N/Aa 
Fuel Handling Machine and 
grapples (Wet Remediation) 
Failure of the Fuel Handling Machine during a seismic event, leading to a 
dropped fuel assembly or a basket loaded with fuel assemblies. A bounding 
material at risk for this SSC failure corresponds to the case in which the Fuel 
Handling Machine is transferring a basket full of sixteen BWR or nine PWR 
assemblies in the remediation pool (Assumption 5.2.3.3) when the seismic event 
occurs. 
Spent Fuel Transfer Machine 
(Dry Transfer) 
Failure of the Spent Fuel Transfer Machine during a seismic event, leading to 
dropped fuel assemblies. A bounding material at risk for this SSC failure 
corresponds to the case in which all spent fuel transfer machines in DTF and 
FHF are suspending a CSNF fuel assembly above another CSNF fuel assembly 
when the seismic event occurs. Each assembly dropped is itself assumed to 
breach along with the assembly it falls upon (Assumption 5.2.1.3). Given that 
there is one spent fuel transfer machine in each of the two DTFs (BSC 2005 
[DIRS 171428], Section 6.6.3.7) and one spent fuel transfer machine in the FHF 
(BSC 2005 [DIRS 171428], Section 6.6.4.4), at most three drops breaching six 
assemblies could occur. 
Inlet and outlet dampers and 
ducting for fuel element 
staging areas (DTF only, 
Surface Industrial HVAC) 
Failure of dampers and ducting required for passive airflow. Interruption of 
airflow would not initiate an event sequence (Section 6.3.1.26) 
Stack for fuel element staging 
areas (DTF only, Surface 
Industrial HVAC) 
Interruption of HVAC due to a collapse of the stack in an uncontrolled manner. 
Interruption of airflow would not initiate an event sequence (Section 6.3.1.26) 
HEPA filters (Primary Surface 
Nuclear HVAC, accumulate 
radioactive material) 
Failure of HEPA filters leading to discharge of accumulated radioactive material. 
Source term has not been estimated, but may be negligible compared to 
releases from breached fuel assemblies. 
Exhaust ducting and dampers 
(Primary Surface Nuclear 
HVAC, accumulate 
radioactive material) 
Failure of ducting and dampers leading to discharge of accumulated radioactive 
material. Source term has not been estimated, but may be negligible compared 
to releases from breached fuel assemblies. 
NOTE: aN/A (not applicable) because there is negligible offsite exposure. 
6.2.7 Tornado and Extreme Wind 
Tornado missiles and tornado winds are addressed in a separate calculation, which generates 
design requirements as described in Section 4.1.13. Transportation casks used for shipping SNF 
and HLW to the repository are large, heavy, robust, sealed metal containers that are certified by
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 88 April 2005 
the NRC in accordance with 10 CFR Part 71 [DIRS 171308]. They provide shielding from 
radiation and protection from hazards to ensure public health and safety during transportation. 
The certification process of transportation casks under 10 CFR Part 71 [DIRS 171308] yields 
adequately robust casks for their intended use and handling at the repository (Assumption 
5.1.2.3). 
6.2.8 Lightning 
Loss of power due to any cause, including lightning strikes will not initiate an event sequence for 
the reasons given in Section 6.2.4. Direct initiation of event sequences due to lightning, for 
example by voltage surges that affect equipment operation, is prevented by compliance with 
design criteria that specify design features that mitigate the effects of lightning (Section 4.3.4). 
This provides reasonable protection against direct initiation of event sequences by lightning 
striking elevated structures. The design criteria specified may not cover transportation casks and 
aging casks (including MSCs and HAMs) being staged or moved on site. For transportation 
casks and transfer casks, the certification process for transportation casks under 10 CFR Part 71 
[DIRS 171308] is assumed to ensure that transportation casks and transfer casks provide 
adequate protection against external hazards (Assumption 5.1.2.3). For aging casks, safety 
strategies have been identified to ensure that there are no Category 1 or Category 2 event 
sequences initiated by lightning (Section 4.1.11). 
6.2.9 Volcanism-Ash Fall 
Ash fall could occur due to a regional volcanic eruption. A design requirement will ensure that 
the surface facilities where SNF and HLW are handled or stored are designed to withstand 
ashfall from a regional volcanic eruption (Assumption 5.1.2.7). 
6.2.10 Drift Degradation 
Drift degradation is the partial or complete collapse of main, turnout, or emplacement drifts as a 
result of rockfall. Rockfalls are discussed in Sections 6.3.6.1.9, 6.3.6.1.20 and 6.3.6.1.21, which 
conclude that rockfalls will not initiate a Category 1 or Category 2 event sequence. 
6.2.11 Extreme Weather Fluctuation-Temperature 
SNF aging casks (including MSCs and HAMs) on the aging pads and transportation casks or 
transfer casks staged on site could be affected by extended periods of exposure to high 
temperature and high solar radiation. Safety strategies to address this hazard for SNF aging 
casks have been developed (Section 4.1.11). To be licensed, transportation casks must be 
evaluated under normal conditions of transport, which include high and low ambient 
temperatures and insolation, and under hypothetical accident conditions (Section 4.2.1). 
Transfer casks are expected to be substantially similar to transportation casks (BSC 2005 [DIRS 
171161] Section 4.1.1.2). Therefore, the requirements of 10 CFR 71 [DIRS 171308] provide 
assurance in accordance with 10 CFR 63.102(f) [DIRS 158535] that transportation casks will not 
be breached by extreme weather fluctuations.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 89 April 2005 
6.2.12 Sandstorm 
Filters or natural circulation vent paths of SNF aging casks (including MSCs and HAMs) could 
be clogged as a result of a sandstorm. An operational requirement will ensure that no event 
sequences are initiated by sandstorms (Assumption 5.1.2.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 90 April 2005 
6.3 CATEGORIZATION OF INTERNAL EVENT SEQUENCES 
Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428]) identifies internal 
events and describes the facilities and operations to which the internal events apply (see Section 
4.1.5 of this document). The present section categorizes each of the internal events that are 
identified in Internal Hazards Analysis for License Application. Because the design and 
operational descriptions are not repeated here, the reader should consult Internal Hazards 
Analysis for License Application whenever a more complete understanding of an event is needed. 
The following six types of potential internal hazards that can initiate an event sequence are 
discussed: 
 Collision-Crushing 
 Chemical Contamination-Flooding 
 Explosion-Implosion 
 Fire-Thermal 
 Radiation 
 Fissile 
The expected number of occurrences of an event sequence determines whether it is categorized 
as Category 1, Category 2, or Beyond Category 2. The analysis relies on assumptions when 
repository design and operating details that are needed to perform the categorization calculations 
are not available. Wherever assumptions call for particular design or operational details to 
prevent or reduce the frequency of an event sequence, the assumption becomes the basis for a 
design or operational requirement. 
The 2-over-1 phenomenon where a structure, system, or component (SSC) may not perform a 
safety function by itself, but its failure may adversely affect the safety function of another SSC, 
will be considered in the facility design (Assumption 5.1.1.37). System interaction that includes 
the adverse effects of failure of a lower seismic design category SSC on the safety function of a 
higher seismic design category SSC will be considered in the design (Assumption 5.1.1.37). 
This analysis considers many specific 2-over-1 events. However, more such events will 
probably be identified as the design evolves. 
This analysis treats DOE SNF canisters differently from other canisters and uncanistered CSNF 
assemblies. For DOE SNF canisters, lift heights are restricted. The canisters are required to 
withstand drops from the allowable heights without causing a Category 1 or Category 2 event 
sequence. Radiological releases from naval canisters, HLW canisters, DPCs, and individual 
CSNF assemblies are presumed whenever there is a drop from any height. The corresponding 
event sequences are categorized according to the expected number of drops over the life of the 
facility. 
As shown in Figure 2, the repository includes a TCRRF, where the transportation cask is 
removed from the commercial cask transporter, and three different processing building designs 
(CHF, DTF, and FHF) where waste can be transferred from transportation casks into canisters or 
WPs, with possible intermediate transfers into staging racks or the SNF Aging System (BSC 
2005 [DIRS 171428], Section 6.6.1). The commercial transporter can be a legal-weight truck
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 91 April 2005 
(LWT), a overweight truck (OWT), or a rail car (BSC 2005 [DIRS 171428], Section 6.6.1). 
Table 8 summarizes the numbers of waste-form units that are assumed for this calculation. 
Figure 2. Waste Flow 
Table 8. Assumed Numbers of Waste-Form Units to Be Received Over the Life of the Repository 
Waste Form Unit 
Number To 
Be Receiveda 
Assumption 
Reference for 
Number 
Received 
Assumed 
Number of 
Items per 
Transportation 
Cask 
Number of 
Associated 
Transportation 
Casksb 
Bare CSNF assemblies 221,000 5.2.1.4 NA = 9,508 c 
DPCs = 9,508 5.2.1.7 1d = 9,508 
Standardized DOE SNF 
canisters 
3,203 5.2.1.5 9e 356 
MCO canisters 404 5.2.1.6 4e 101 
HLW canisters 16,070 5.2.1.8 5e 3,214 
Naval SNF canisters 300 5.2.1.9 1e 300 
NOTES: aThese numbers are used for event sequence categorization calculations. They are conservative 
and are not intended to reflect the actual numbers to be received. CSNF assemblies shipped in 
DPCs are included in the quoted number of bare CSNF assemblies. 
bColumn 2 divided by Column 4. The number of casks in the first two rows are mutually exclusive 
maximums. The first number assumes no CSNF assemblies come in DPCs and the second 
assumes that all CSNF casks contain assemblies packaged in DPCs. Accounting for the 
redundancy in the first two rows, the sum of the column is 13,479. 
cAssumption 5.2.1.7. 
dThe design analyzed does not consider the possibility of more than one DPC per cask (BSC 2005 
[DIRS 171428], Section 6.6.3.15). 
eAssumption 5.2.1.13.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 92 April 2005 
6.3.1 Generalized Event Sequence Analyses 
Beginning with Section 6.3.2, each third-level subsection of Section 6.3 pertains to a functional 
area defined in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428]). 
In some cases, a number of specific events that were separately identified in Internal Hazards 
Analysis for License Application are generalized and presented in this section. Event trees that 
are developed in this section are designated by GET for generalized event tree and numbered 
sequentially, for example, GET-01. Each event tree designation is appended parenthetically to 
the title of the section where it is developed. 
6.3.1.1 Drop of a transportation or transfer cask (without impact limiters) or MSC 
from an overhead crane (GET-01) 
6.3.1.1.1 Transportation or transfer cask drop (including slapdown) 
This section considers drop (including slapdown) of transportation casks without impact limiters 
and of transfer casks without impact limiters. The transfers may take place in the TCRRF, DTF, 
CHF, or FHF. 
Casks that are bound for the DTF or CHF undergo two or three crane transfers as follows. The 
Transportation Cask Receipt and Return Area overhead bridge crane, which is located in the 
TCRRF, lifts each transportation cask for transfer to an SRTC. No credit is taken here for 
impact limiters, which may or may not be in place on the transportation casks during the initial 
crane transfers (BSC 2005 [DIRS 171428], Section 6.6.1). A second crane transfer is required in 
the DTF or CHF. In the CHF, the cask is transferred to a cask preparation pit (BSC 2005 [DIRS 
171428], Section 6.6.2.2). In the DTF, the cask is transferred to a trolley (BSC 2005 [DIRS 
171428], Section 6.6.3.1). An additional crane transfer is required for a transportation cask 
containing a horizontal DPC that has been selected for transfer to a HAM; each such cask will 
undergo a crane transfer to a horizontal cask transfer trailer for the transfer to an aging pad. 
Upon return from aging in a transfer cask, two crane transfers are required, as is the case for 
incoming transportation casks (BSC 2005 [DIRS 171428], Section 6.6.1). 
Casks that are bound for the FHF undergo two or three crane transfers as follows (BSC 2005 
[DIRS 171428], Section 6.6.4). Casks with uncanistered SNF are transferred (1) from the 
conveyance to an import-export trolley, and (2) from there to a transfer trolley (two transfers). 
Casks with canistered waste are transferred (1) from the conveyance to an import-export trolley, 
and (2) from there to a position on the floor of the transfer cell (two transfers). HI-STAR casks, 
which contain a DPC canister, must be tilted in a separate fixture, which introduces a third 
transfer. 
Although at most three crane transfers per cask are required, four transfers per cask are 
conservatively used for the categorization calculation. Figure 3 illustrates the logic for the 
categorization calculations. The probabilities of each branch are estimated in Table 9. 
Categorization calculations are presented in Table 10. The approach taken to prevent Category 1 
and Category 2 event sequences involving DOE SNF canisters is discussed in Section 4.1.18. 
The height limit depends on the contents of the cask (Assumption 5.1.1.18). For casks that
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 93 April 2005 
contain MCO canisters, credit may be taken for impact absorption by structural features other 
than the MCO canisters (Assumption 5.1.1.18). 
Number of drops of 
transportation 
casks or transfer 
casks without 
impact limiters 
Cask contains 
CSNF, naval SNF, 
or HLW 
Lift-height limit 
respected 
Canister meets 
specifications 
Categorization 
formula 
P(Yes) = 1 - p1 Breach presumed A. C N ( 1 - p1 ) 
P(Yes)  1 B. No breach 
C N 
P(Yes)  1 
P(No) = p3 C. C N p1 p3 
P(Noa) = p1 
P(No) = p2 D. C N p1 p2 
NOTE: a No here indicates that the cask contains DOE SNF. 
Figure 3. GET-01: Logic for Drop of a Transportation Cask or Transfer Cask without Impact Limiters 
Table 9. Inputs for Drop of a Transportation Cask or Transfer Cask without Impact Limiters 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N The expected number of dropped transportation or transfer 
casks is given by the number of casks (13,479) the number of 
times each cask is transferred (4) times the crane load-drop 
rate (1E-05 drops/transfer). 
5.4E-01 Assumptions 5.2.1.10 
and 5.1.1.10 
p1 Fraction of casks that are DOE SNF casks 
(457/13,479). 
3.39E-02 Table 8 
p2 The conditional probability of exceeding the lift-height limit given 
that a drop occurred. 
1.0E-04 Assumptions 5.1.1.12 
and 5.1.1.18. 
p3 The probability that one or more of the DOE canisters in the 
cask is defective such that it may breach if dropped from within 
the lift-height limit. The probability that a given canister is 
defective is 2.3E-04. Each DOE cask may contain up to 9 
canisters. The probability that the cask contains one or more 
defective canisters is given by 1  (1  2.3E-04)9. The resulting 
probability is conservative for MCO casks, which only contain 4 
MCOs. 
2.1E-03 Section 4.1.18. Table 8.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 94 April 2005 
Table 10. Categorization Calculations for Drop of a Transportation Cask or Transfer Cask without Impact 
Limiters 
Event 
ID 
Contents of Cask 
(Material at Risk) 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister. 
C N (1  p1) 5.7E-01 Category 2 Number of transportation 
cask receipts. Fraction that 
are not DOE SNF. Craneload 
drop rate. 
B DOE SNF canisters NA NA No breach Lift height limit respected. 
Canister meets 
specifications. 
C DOE SNF canisters C N p1 p3 4.2E-05 Beyond 
Category 2 
Numbers of DOE SNF casks 
Crane load-drop rate. 
Canister defect rate. 
D DOE SNF canisters C N p1 p2 2.0E-06 Beyond 
Category 2 
Numbers of DOE SNF 
canister casks. Crane loaddrop 
rate. Crane lift-height 
reliability. 
6.3.1.1.2 MSC drop (including slapdown) 
The expected number of transportation cask drops determined for the cask-drop event in Section 
6.3.1.1.1 bounds the corresponding number for a MSC-drop event because the parameters 
needed for the MSC-drop event are less than or equal to the corresponding parameters in the 
transportation-cask event: 
 The number of MSCs handled is less than the number of transportation cask receipts. 
MSCs are similar to transportation casks and will hold approximately the same amount 
of waste (Assumption 5.2.4.1). However, not all waste will be placed into MSCs and 
sent to an aging pad. Waste that is not in need of aging (including standardized DOE 
SNF canisters, HLW canisters, and low-heat CSNF assemblies) will only be sent to the 
aging pads if staging is required (Assumption 5.2.1.20). Furthermore, naval SNF and 
MCOs will not be sent to the aging pads (Assumption 5.2.1.20). 
 The assumed drop rate for the crane is the same in each case. 
 There are no more than four transfers associated with the MSC drop. The bounding case 
occurs when an MSC is both loaded and unloaded at the FHF. After an MSC is loaded 
at the FHF, it is transferred by crane (1) from the transfer trolley to the import-export 
trolley and from there (2) to a position on the floor for pickup by the MSC transporter 
(two transfers). An MSC that arrives at the FHF for unloading is transferred (3) from its 
position on the floor to the import-export trolley, and (4) from there to the transfer 
trolley (two transfers). This is the same number of transfers used for the transportationcask 
drop. 
 The conditional probability, given a drop, of exceeding the lift-height requirement is the 
same in each case.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 95 April 2005 
 There is no need to age DOE SNF, and DOE SNF will only be sent to the aging pad if 
staging is required. 
The consequences are approximately the same in each case because it is assumed that the 
capacities of MSCs are approximately the same as those of transportation casks (Assumption 
5.2.4.1). Given that the drop of a transportation cask will at most lead to a Category 2 event 
sequence (see Section 6.3.1.1.1), it is therefore concluded that the drop of an MSC is also, at 
most, a Category 2 event sequence whose consequences are not more severe than those of a 
transportation cask drop. 
6.3.1.2 Drop or collision of the inner lid of a transportation or transfer cask, MSC, or 
WP into an open transportation cask, MSC, or WP (GET-02) 
This section considers lid drops into open transportation casks, MSCs, and WPs. Because the lid 
must enter from the top, only collisions resulting from drops are considered. Lid drops that 
affect DOE or naval canisters may occur in CHF, DTF, or FHF. Lid drops that affect bare CSNF 
may only occur in DTF or FHF. After the inner lid of a transportation cask or MSC is removed, 
the lid could be dropped back into the opening of the cask. If the lid rotates before impact, its 
edge could strike the contents of the cask. A similar event sequence could unfold just prior to 
placing the inner lid on a WP or MSC. The maximum number of opportunities for this event 
corresponds to the case in which the contents of a transportation cask are first transferred to an 
MSC, and after a period of aging, from the MSC to a WP. The opportunities for a lid drop in this 
conservatively selected scenario are as follows: 
1. Drop into a transportation cask before unloading 
2. Drop into an MSC after loading 
3. Drop into an MSC before unloading 
4. Drop into a WP after loading. 
Thus, there are at most four opportunities for the event for each transportation cask received. 
DOE SNF canisters are assumed to withstand a lid drop up to a specified height without breach 
(Assumption 5.1.1.22). Naval canisters, HLW canisters, DPCs, and individual CSNF assemblies 
may breach as a result of lid drop from any height. A simplified calculation can be performed if 
the numbers of MSCs and WPs are taken to be equal to the assumed number of cask shipments 
(Assumption 5.2.1.10). This approach is conservative because the number of transportation cask 
receipts (13,479, Assumption 5.2.1.10) is greater than or equal to the number of WPs (11,184, 
Section 4.1.1). Naval canisters will not be staged or sent to the aging pads and DOE canisters 
are not expected to be sent to the aging pads (Assumption 5.2.1.20). The scenario modeled here 
conservatively includes a trip to a staging rack for naval and DOE canisters (Assumption 
5.2.1.2). Figure 4 illustrates the logic for the categorization calculations. The probabilities of 
each branch are estimated in Table 11. The categorization calculations are presented in Table 
12. 
In the absence of structural evaluations that could determine the maximum amount of material at 
risk, the maximum capacities of transportation casks may be used as bounding. Thus, 74 BWR
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 96 April 2005 
assemblies or 36 PWR assemblies (Assumption 5.1.1.34), 5 HLW canisters (Assumption 
5.2.1.13), or 1 naval canister (Assumption 5.2.1.13) may be affected. 
The following considerations ensure that the expected number of drops with the potential for 
exposure of individuals to radiation has been calculated conservatively: 
 The lid may fall onto the floor. 
 The lid may fall into the cask or WP but fail to rotate into a position that could damage 
the fuel. 
 For bare CSNF assemblies, the basket structure within the WP or cask would absorb 
energy. 
 Transportation or transfer casks that contain DPCs have been included with no credit for 
the canisters. 
 The lid would not penetrate the opening farther than one radius of the lid, which would 
spare much of the contents from the impact. 
 An aging step has been allowed for CSNF, but only a fraction of the CSNF would be 
aged. 
Number of 
cask receipts 
Cask contains 
CSNF, HLW, or 
naval SNF 
Lid retained by 
crane 
Lift-height limit for 
lids above DOE SNF 
canisters respected 
Canister meets 
specifications 
Categorization 
formula 
P(Yes)  1 A. No drop 
P(Yes) = 1 - p1 
P(No) = p2 Breach presumed B. C N (1 - p1) p2 
C N 
P(Yes)  1 C. No drop 
P(Yes)  1 D. No breach 
P(Noa) = p1 
P(Yes)  1 
P(No) = p2 P(No) = p4 E. C N p1 p2 p4 
P(No) = p3 F. C N p1 p2 p3 
NOTE: a No here indicates that the cask contains DOE SNF. 
Figure 4. GET-02: Logic for Drop of an Inner Lid into a Transportation or Transfer Cask, WP, or MSC
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 97 April 2005 
Table 11. Inputs for Inner-Lid Drop on a Canister in a Transportation or Transfer Cask, WP, or MSC 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of cask receipts. 13,479 Table 8 
p1 Fraction of transportation cask receipts that contain DOE SNF 
canisters. 
3.39E-02 Table 8 
p2 Probability of a lid drop is given by the number of opportunities 
for a drop (4) times the drop rate (10-5 drops per opportunity). 
4E-05 See discussion above in 
this section. Assumption 
5.1.1.10. 
p3 The conditional probability of exceeding the specified maximum 
lift height given a drop. 
1E-04 Assumption 5.1.1.12, 
Assumption 5.1.1.22. 
p4 The probability that a DOE SNF canister is defective and would 
breach if dropped from within the lift-height limit. 
2.3E-04 Section 4.1.18 
Table 12. Categorization of Inner-Lid Drop into a Transportation or Transfer Cask, WP, or MSC 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister 
NA NA No drop Crane reliability 
B 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister 
C N (1  p1) p2 5.7E-01 Category 2 Numbers of casks. Crane 
load-drop rate. 
C DOE SNF canister NA NA No drop Crane reliability 
D DOE SNF canister NA NA No breach Lift height limits respected. 
Canister meets 
specifications. Structural 
capabilities of canister. 
E DOE SNF canister C N p1 p2 p4 4.6E-06 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Canister 
defect rate. Lid lift-height 
requirement 
F DOE SNF canister C N p1 p2 p3 2.0E-06 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Crane liftheight 
reliability. Lid liftheight 
requirement.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 98 April 2005 
6.3.1.3 Drops and collisions of CSNF assemblies during transfer (GET-03) 
This section considers assembly-drop and assembly-collision events in the DTF (except as 
associated with remediation activities) and FHF as generalized drop and collision events. Credit 
is taken for mitigation of radiological releases by the Surface Nuclear HVAC System for 4 h 
after an assembly drop or collision. The logic for categorization of drop and collision events is 
presented in Figure 5. The probabilities of each branch are estimated in Table 13. The 
categorization calculations are presented in Table 14. Assembly drops could involve one CSNF 
assembly falling onto another, so two assemblies are at risk from an assembly drop. For a 
collision of an assembly with an object during transfer, only one assembly is at risk. 
The event sequences involving drops (and the event sequences involving collisions) of a CSNF 
assembly followed by a failure of the Surface Nuclear HVAC system, including HEPA filtration, 
is kept below the Category 1 event sequence threshold by specifying a required HVAC 
reliability. Based on the 0.01 probability, p3 in Table 13, which renders the event sequence a 
Category 2, an hourly failure rate of 0.01/4 h = 2.5  10-3 h-1 or less is adopted as a design 
requirement for the HVAC system (Assumption 5.1.1.48). Emergency power is not credited. 
Normal operations would be suspended if offsite power were to become unavailable 
(Assumption 5.1.1.49). 
Number of CSNF 
assemblies 
Assembly retained 
during transfer 
Assembly collision 
avoided 
HVAC, including 
HEPA, functions for 
at least 4 h after 
handling event 
Categorization 
formula 
P(Yes)  1 A. No collision 
P(Yes)  1 P(Yes)  1 B. C N p2 
P(No) = p2 
C N P(No) = p3 C. C N p2 p3 
P(Yes)  1 D. C N p1 
P(No) = p1 
P(No) = p3 E. C N p1 p3 
Figure 5. GET-03: Logic for Drops and Collisions of CSNF Assemblies
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 99 April 2005 
Table 13. Inputs for Drops and Collisions of CSNF Assemblies 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of CSNF assemblies. 221,000 Assumption 5.2.1.4 
p1 Probability of a drop of a CSNF assembly is given by the 
maximum number of transfers (4) times the assembly-drop rate 
of the spent fuel transfer machine (10-5). 
4E-05 Assumptions 5.2.1.1 and 
5.1.1.7 
p2 Probability of a collision of a CSNF assembly is given by the 
maximum number of transfers (4) times assembly-collision rate 
of the spent fuel transfer machine (10-5). 
4E-05 Assumptions 5.2.1.1 and 
5.1.1.8 
p3 Probability that HEPA filtration becomes unavailable within 4 h 
of a handling event due to loss of offsite power or failure of the 
HVAC system. 
1E-02 Assumption 5.1.1.48 
Table 14. Categorization Calculations for Drops and Collisions of CSNF Assemblies 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A No event NA NA No collision Transfer operation reliability 
B 1 assembly 
(Assumption 5.2.1.3) 
C N p2 9.7 
collisions 
Category 1 Numbers of assemblies. 
Collision rate. Availability of 
HEPA filtration for 4 h. 
C 1 assembly C N p2 p3 9.7E-02 
collisions 
Category 2 Numbers of assemblies. 
Collision rate. 
D 2 assemblies C N p1 9.7 drops Category 1 Numbers of assemblies. Drop 
rate. Availability of HEPA 
filtration for 4 h. 
E 2 assemblies C N p1 p3 9.7E-02 
drops 
Category 2 Numbers of assemblies. 
Load drop rate. 
For the radiological consequence analysis, it is necessary to determine the annual frequency of 
Category 1 event sequences corresponding to the maximum anticipated rate of receipt of 
radioactive waste (Section 6.1.2). Given a maximum receipt rate of 3,600 MTHM/y 
(Assumption 5.1.1.1), a total receipt of 63,000 MTHM (Section 4.3.1), and a total of 221,000 
assemblies (Assumption 5.2.1.4), the maximum number of assemblies processed in a single year 
is estimated to be: 
(221,000 assemblies) (3,600 MTHM/y)/(63,000 MTHM) = 12,628 assemblies/y. 
Given a drop rate of 10-5 drops per transfer (Assumption 5.1.1.7), and a collision rate of 10-5 
collisions per transfer (Assumption 5.1.1.8), the annual frequencies of drops or collisions in the 
maximum year are: 
(12,628 assemblies/y) (10-5 events/transfer) (4 transfers/assembly) = 0.5 events/y.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 100 April 2005 
6.3.1.4 Drop or collision of handling equipment onto or against a CSNF assembly in the 
DTF or FHF (GET-04) 
This section considers events involving equipment drop or collision onto or against CSNF 
assemblies in the DTF or FHF. During transfer operations, handling equipment from the spent 
fuel transfer machine could impact a CSNF assembly. Handling equipment from the spent fuel 
transfer machine may strike a CSNF assembly in a staging rack, WP, MSC, or transportation 
cask. 
The logic for categorization is presented in Figure 6. The probability of the event sequence is 
estimated in Table 15. The categorization calculation is presented in Table 16. No more than 
one assembly will be breached as a result of this event sequence (Assumption 5.2.1.11). 
Number of CSNF 
assemblies 
Handling equipment drop 
or collision avoided Categorization formula 
P(Yes)  1 A. No drop or collision 
C N 
P(No) = p1 B. C N p1 
Figure 6. GET-04: Logic for Drop or Collision of Handling Equipment onto or against CSNF Assemblies 
Table 15. Inputs for Drops or Collision of Handling Equipment onto or against CSNF Assemblies 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of CSNF assemblies. 221,000 Assumption 5.2.1.4 
p1 Probability of a drop or collision of handling equipment is given 
by the maximum number of transfers (4) times the rate of drop 
or collision of handling equipment of the spent fuel transfer 
machine (10-7). 
4E-07 Assumptions 5.2.1.1 and 
5.1.1.9. 
Table 16. Categorization Calculations for Drop or Collision of Handling Equipment onto or against CSNF 
Assemblies 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A No event NA NA No drop or 
collision 
Fuel transfer machine 
reliability 
B 1 assembly C N p1 9.7E-02 Category 2 Number of assemblies. Loaddrop 
rate.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 101 April 2005 
6.3.1.5 Drop (including slapdown) of a DOE, naval, or DPC canister (GET-05) 
This section considers the drop (including slapdown) of DOE, naval, and DPC canisters during 
handling by crane in CHF, DTF, or FHF. Standardized DOE SNF canisters, DOE MCO 
canisters, HLW canisters, naval canisters, and DPCs will be transferred by overhead bridge 
crane. A scenario that includes staging of canisters is used for the categorization calculations. 
Canisters are assumed to be transferred two times on average (Assumption 5.2.1.2). Figure 7 
illustrates the logic. The probabilities of each branch are estimated in Table 17. Table 18 
presents the categorization calculations. Table 19 covers drops of one canister onto another 
canister. 
Although breach of the naval canister is presumed with a drop from any height, the source term 
for releases from the naval canister is based on drop scenarios provided to the U.S. Navy 
(Assumption 5.1.1.42). Similarly, DPCs and HLW canisters are assumed to breach as a result of 
a drop from any height. To allow appropriate source terms to be chosen for the consequence 
analysis, a lift-height limit is assumed for DPCs (Assumption 5.1.1.43) and HLW canisters 
(Assumption 5.1.1.24). To avoid overly complicating the event tree, the remote possibility of 
drops from above the maximum lift heights are not shown for lifts of naval SNF, DPCs, and 
HLW canisters. 
Number of DOE 
SNF, HLW, 
naval, and DPC 
canisters 
Canister is a 
DPC, HLW, or 
naval canister 
Crane retains 
canister for all 
transfers 
Lift-height limit 
above DOE SNF 
canisters respected 
DOE SNF 
canister meets 
specifications 
Categorization 
formula 
P(Yes)  1 A. No drop 
P(Yes) = 1 - p1 
P(No) = p2 Breach presumed B. C N ( 1 - p1 ) p2 
C N 
P(Yes)  1 C. No drop 
P(Yes)  1 D. No breach 
P(Noa) = p1 
P(Yes)  1 
P(No) = p2 P(No) = p4 E. C N p1 p2 p4 
P(No) = p3 F. C N p1 p2 p3 
NOTE: a No here indicates that the canister contains DOE SNF. 
Figure 7. GET-05: Logic for Canister Drop
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 102 April 2005 
Table 17. Inputs for Drop of a Canister 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of DOE, naval, and DPC canisters handled (because 
CSNF assemblies arrive in DPCs). 
29,485 Table 8 
p1 Fraction of canisters that are DOE SNF canisters 1.22E-01 Table 8 
p2 Probability of a crane drop is estimated as the number of 
transfers (2) times the crane load-drop rate (10-5). 
2E-05 Assumptions 5.2.1.2 and 
5.1.1.10 
p3 The conditional probability of exceeding the lift height given a 
drop. 
1E-04 Assumptions 5.1.1.12, 
5.1.1.14, and 5.1.1.15 
p4 The probability that a DOE SNF canister is defective and would 
breach if dropped from within the lift-height limit. 
2.3E-04 Section 4.1.18. 
Table 18. Categorization Calculations for Canister Drop 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A No drop NA NA No drop Crane reliability 
B 2 HLW canisters 
(Table 19, Row 1), 1 
naval canister or 1 
DPC 
C N (1  p1) p2 5.7E-01 Category 2 Numbers of canisters. Crane 
load-drop rate. 
C No drop NA NA No drop Crane reliability 
D DOE SNF canister NA NA No breach Numbers of canisters. Crane 
load-drop rate. Ability of 
canisters to withstand drop 
(Section 4.1.18). Crane liftheight 
restrictions 
(Assumptions 5.1.1.14 and 
5.1.1.15). 
E DOE SNF canister C N p1 p2 p4 1.8E-05 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Canister 
defect rate. 
F DOE SNF canister C N p1 p2 p3 7.9E-06 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Crane liftheight 
reliability.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 103 April 2005 
Table 19. Categorization Comments for Drops of One Canister onto Another Canister 
Row 
Canister 
Dropped Canister Hit Categorization Comment 
1 HLW HLW Both canisters breach. This event is covered in Table 18, Event B. The 
material at risk is two HLW canisters for this event. This sets the 
bounding material at risk in Table 18, Event B. 
2 HLW Standardized 
DOE SNF 
HLW canister breaches, SNF canister does not breach (Assumptions 
5.1.1.24 and 5.1.1.25). This event is covered in Table 18, Event B. 
3 HLW MCO HLW canister breaches, but the MCO does not breach (Assumptions 
5.1.1.24 and 5.1.1.25). This event is covered in Table 18, Event B. 
4 Standardized 
DOE SNF 
Standardized 
DOE SNF 
Beyond Category 2. Standardized DOE SNF canisters will not breach if 
dropped on each other (Assumptions 5.1.1.28). 
5 Standardized 
DOE SNF 
MCO This combination is not applicable because standardized DOE SNF 
canisters and MCOs are not shipped together (Table 8) or disposed of 
together (Table 1) and MCOs are not staged (Assumption 5.2.1.20). 
6 Standardized 
DOE SNF 
HLW Rendered Beyond Category 2 by an operational requirement not to 
transfer a standardized DOE SNF canister into a WP if there are one or 
more HLW canisters present in the WP or MSC (Assumption 5.1.1.23). 
7 MCO Standardized 
DOE SNF 
See Row 5. 
8 MCO MCO Beyond Category 2. MCOs will not breach if dropped on each other 
(Assumption 5.1.1.28). 
9 MCO HLW Rendered Beyond Category 2 by an operational requirement not to 
transfer a standardized DOE SNF canister into a WP if there are one or 
more HLW canisters present in the WP or MSC (Assumption 5.1.1.23). 
6.3.1.6 Drop or collision of handling equipment onto or against a DOE, naval, or DPC 
canister (GET-06) 
This section considers drop or collision of handling equipment onto DOE, naval, and DPC 
canisters in the DTF, CHF, or FHF. (Note that MCOs are not handled in the FHF.) During 
transfer operations, handling equipment could strike a canister inside a cask or WP or in a 
staging rack. In this potential event, a drop has to occur to cause a collision because the 
equipment will be suspended above the canister. This event only applies to canister transfers 
because the overhead bridge crane is not used to transfer individual fuel assemblies. On average, 
each canister is assumed to be transferred two times (Assumption 5.2.1.2). Each transfer could 
result in an equipment drop onto the canister intended for transfer or another canister of the same 
type (Assumption 5.1.1.11). Figure 8 illustrates the logic for the categorization calculations. 
The probabilities of each branch are provided in Table 20. Table 21 presents the categorization 
calculations.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 104 April 2005 
Number of DOE 
SNF, HLW, 
naval, and DPC 
canisters 
Canister is a 
DPC, HLW, or 
naval canister 
Handling 
equipment 
retained 
Lift-height limit 
above DOE SNF 
canisters respected 
DOE SNF 
canister meets 
specifications 
Categorization 
formula 
P(Yes)  1 A. No drop 
P(Yes) = 1 - p1 
P(No) = p2 Breach presumed B. C N ( 1 - p1 ) p2 
C N 
P(Yes)  1 C. No drop 
P(Yes)  1 D. No breach 
P(Noa) = p1 
P(Yes)  1 
P(No) = p2 P(No) = p4 E. C N p1 p2 p4 
P(Yes) = p3 F. C N p1 p2 p3 
NOTE: a No here indicates that the canister contains DOE SNF. 
Figure 8. GET-06: Logic for Handling-Equipment Drop onto a Canister 
Table 20. Inputs for Handling-Equipment Drop onto a Canister 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of DOE, naval, and DPC canisters handled. 29,485 Table 8 
p1 Fraction of canisters that are DOE SNF canisters 1.22E-01 Table 8 
p2 Probability of a handling-equipment drop onto a canister is 
estimated as the number of transfers (2) times the handlingequipment 
drop rate per transfer (10-5). 
2.E-05 Assumptions 5.2.1.2 and 
5.1.1.11. 
p3 The conditional probability of exceeding the lift height given a 
drop. 
1.E-04 Assumptions 5.1.1.12 
and 5.1.1.31. 
p4 The probability that a DOE SNF canister is defective and would 
breach if dropped from within the lift-height limit. 
2.3E-04 Section 4.1.18.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 105 April 2005 
Table 21. Categorization of Handling-Equipment Drop onto a Canisters 
Event 
ID 
Canister Affected 
(Material at Risk) 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A HLW, naval, or DPC 
canister 
NA NA No drop Crane reliability. 
B HLW, naval, or DPC 
canister 
C N (1 - p1) p2 5.7E-01 Category 2 Numbers of canisters. 
Number of transfers. Crane 
load-drop rate. 
C DOE SNF canister NA NA No drop Crane reliability 
D DOE SNF canister NA NA No breach Numbers of canisters. 
Number of transfers. Crane 
load-drop rate. Structural 
capabilities of canister. 
E DOE SNF canister C N p1 p2 p4 1.8E-05 Beyond 
Category 2 
Number of DOE SNF 
canisters. Number of 
transfers. Crane load-drop 
rate. Canister defect rate. 
F DOE SNF canister C N p1 p2 p3 7.9E-06 Beyond 
Category 2 
Number of DOE SNF 
canisters. Number of 
transfers. Crane load-drop 
rate. Crane lift-height 
reliability.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 106 April 2005 
6.3.1.7 Drop (including slapdown) of a loaded, unsealed WP from an overhead crane 
(GET-07) 
This section considers drops (including slapdown) of unsealed WPs prior to closure of the WP 
in CHF, DTF, or FHF. (Note that individual CSNF assemblies are not handled in the CHF and 
that MCOs are not handled in the FHF.) The unsealed WP could fall back into a loading pit, 
onto the floor, onto the edge of a WP pedestal, trolley, or loading pit, and could slap down onto 
the floor, a wall, or the edge of a loading pit. For drops onto a pit edge, the WP may slap down 
across the pit and strike the opposite edge of the pit. The question arises whether a DOE SNF 
canister inside the unsealed WP would withstand the secondary impact of the WP into the 
opposite edge of the pit. The canister itself does not hit the opposite edge of the pit; rather, the 
canister hits either the side of the WP or the internal basket structure of the WP. MCO canisters 
can withstand 2-ft (0.6-m) drops in any orientation with slapdown; standardized DOE SNF 
canisters can withstand much higher drops (Section 4.1.18). The secondary impact of the 
canister into the side of the WP or WP basket structure when the WP hits the opposite edge is 
bounded by a canister slapdown due to the fact that the impact occurs before the WP is 
horizontal and because the WP and the WP basket structure absorb much of the impact energy. 
Therefore, the DOE SNF canister will not breach given a drop of an unsealed WP onto the edge 
of a pit. 
Figure 9 illustrates the logic for the categorization calculations. The probabilities of each branch 
are estimated in Table 22. The categorization calculations are presented in Table 23. 
Drops of unsealed WPs from any height are assumed to breach naval SNF, CSNF, and HLW 
canisters that may be inside. Lift-height limits are specified so that the appropriate source terms 
can be selected for the consequence calculations (Assumption 5.1.1.52). The categorization 
calculations do not address the unlikely scenarios in which those limits are exceeded.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 107 April 2005 
Number of 
WPs 
Crane retains 
unsealed WP 
WP contains 
CSNF assemblies, 
HLW, or naval 
SNF (and no DOE 
SNF) 
Lift-height 
limit 
respected 
DOE SNF canister 
meets specifications Categorization formula 
P(Yes)  1 A. No drop 
C N P(Yes) = 1 - p2 Breach of waste form presumed B. C N p1 (1 - p2) 
P(Yes)  1 C. No waste-form breach 
P(No) = p1 
P(Yes)  1 
P(Noa) = p2 P(No) = p4 D. C N p1 p2 p4 
P(No) = p3 Waste form breaches E. C N p1 p2 p3 
NOTE: a No here indicates that the WP contains DOE SNF. 
Figure 9. GET-07: Logic for Dropping an Unsealed WP 
Table 22. Inputs for Drop of an Unsealed WP 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of WPs. 11,184 Section 4.1.1 
p1 The load-drop rate for the crane (10-5 per transfer) times the 
number of transfers per unsealed WP (1). 
1E-05 Assumption 5.1.1.10 
p2 The ratio of the number of WPs that contain DOE SNF to the 
total number of WPs. 
0.304 Section 4.1.1 
p3 The conditional probability of having exceeded the lift-height 
limit for WPs that contain DOE SNF given that a drop occurred. 
Crush pads protect the WP in case of a fall onto the floor. 
1E-04 Assumptions 5.1.1.12 
and 5.1.1.52. 
p4 The probability that the WP contains a defective DOE SNF 
canister that would breach if the WP is dropped from within the 
lift-height limit. The probability that an individual DOE SNF 
canister is defective is 2.3E-04. A codisposal WP could contain 
2 MCOs. The probability p4 is taken to be the probability that a 
codisposal WP containing two DOE SNF canisters contains one 
or more defective DOE SNF canisters: 1  (1  2.3E-04)2. The 
computed probability is conservative for WPs containing 
standardized DOE SNF canisters because they only contain 
one SNF canister. 
4.6E-04 Section 4.1.18. Table 1
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 108 April 2005 
Table 23. Categorization Calculations for Drop of an Unsealed WP 
Event 
ID Contents of WP 
Categorization 
Formula 
Expected 
Number 
of Events Category 
Features Credited in the 
Categorization Calculation or to 
Prevent Exposure 
A Any waste form NA NA No drop Crane reliability 
B 44 BWR or 21 PWR 
assemblies, 1 naval 
canister, or 5 HLW 
canisters 
C N (1  p2) p1 8.6E-02 Category 2 Load-drop rate of crane. 
C Standardized DOE 
SNF canister or 
MCO 
NA NA No wasteform 
breach 
Load-drop rate of crane. Liftheight 
restriction for crane. Ability 
of canisters to withstand drop 
without breach. Ability of crush 
pads to prevent waste-form 
breach. 
D Standardized DOE 
SNF canister or 
MCO 
C N p1 p2 p4 1.7E-05 Beyond 
Category 2 
Load-drop rate of crane. Liftheight 
restriction for crane. 
Fraction of DOE SNF canisters. 
Defect fraction for DOE SNF 
canisters. 
E Standardized DOE 
SNF canister or 
MCO 
C N p1 p2 p3 3.7E-06 Beyond 
Category 2 
Load-drop rate of crane. Liftheight 
restriction for crane. 
Conditional probability of violating 
lift-height restriction given a drop. 
Fraction of DOE SNF WPs. 
6.3.1.8 Drop of a loaded, sealed WP from an overhead crane (GET-08) 
This section considers drops of sealed WPs from bridge cranes in CHF, DTF, or FHF. The WP 
is assumed to survive a slapdown after a drop from within the allowable lift height without 
breach (Assumption 5.1.3.12) and a backwards slapdown associated with the tilting machine 
(Assumption 5.1.3.12). 
After closure operations are complete, the WP is considered sealed. The sealed WP is 
transferred by crane to the survey station where it is surveyed for radioactive contamination (first 
crane transfer). If necessary, the WP is transferred by crane from the survey station to the trolley 
leading to the decontamination station (second crane transfer). After decontamination, the WP 
may then be staged to await authorization for emplacement (third crane transfer). Once 
emplacement is authorized, the staged WP is transferred by crane to the trolley leading to the WP 
loadout cell (fourth crane transfer). In the WP loadout cell, the WP is transferred by crane from 
the trolley to the WP Tilting Station (fifth crane transfer). A sixth and final transfer by crane is 
needed to place the WP and emplacement pallet onto the bedplate of the waste-package 
transporter. Thus, at most six crane transfers are needed to move the WP from the WP 
positioning cell to the WP transporter. Figure 10 provides the logic for a drop of a sealed WP. 
WPs are assumed to survive, without breach, the impacts described in Assumption 5.1.3.12. A 
WP that is dropped from above the height limits specified in Assumption 5.1.3.12 is assumed to 
breach (Assumptions 5.1.3.9 and 5.1.3.8). Figure 10 illustrates the logic for the categorization 
calculations. The probabilities of each branch are estimated in Table 24. The categorization 
calculations are presented in Table 25.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 109 April 2005 
In contrast to what was done for the DOE SNF canisters, the fact that a WP may be defective is 
not considered in the categorization of sealed WP drops. A defective WP designates a WP with 
a manufacturing defect that may lead to its early failure. An early failure is defined as a throughwall 
penetration occurring at a time earlier than would be predicted by mechanistic degradation 
models for a defect-free WP. As pointed out in Section 6.3.6.5.2, defective WPs have a low 
probability of occurrence. Moreover, the same section indicates that no significant degradation 
of a WP is expected to take place during the preclosure period. Although a defective WP may 
have weld or base-metal flaws that are significant for postclosure performance, dropping a 
defective WP will not cause its failure. The reason for this is that the outer boundary of the WP 
is made of Alloy 22, a material with a high ductility for which brittle fracture is not anticipated at 
the temperatures experienced after waste loading (BSC 2004 [DIRS 169766], p. 84). 
As a part of closure operations, the WP closure welds are nondestructively examined. If a WP 
does not pass the nondestructive examination, then the WP is sent to the remediation system. 
Transfers of WPs with defective closure welds are considered in Section 6.3.1.9. 
Number of WPs Crane retains 
sealed WP 
WP Drop-height limit 
respected 
Categorization 
formula 
P(Yes)  1 A. No drop 
C N P(Yes)  1 B. No breach 
P(No) = p1 
P(No) = p2 C. C N p1 p2 
Figure 10. GET-08: Logic for Drop of a Sealed WP 
Table 24. Inputs for Drop of a Sealed WP 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of WPs. 11,184 Section 4.1.1 
p1 The probability of a drop is given by the maximum number of 
times each WP is transferred by crane (6) times the drop rate 
(10-5). 
6.E-05 Assumption 5.1.1.10 
p2 A design requirement limits the conditional probability of a lift 
above a specified limit given that a drop has occurred. 
1.E-04 Assumption 5.1.1.12
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 110 April 2005 
Table 25. Categorization Calculations for Drop of a Sealed WP 
Event 
ID 
Contents of 
WP Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation or to 
Prevent Exposure 
A Any waste form NA NA No drop Crane reliability 
B Any waste form NA NA No breach Number of WPs. Load-drop rate for the 
crane. Lift-height limit (Assumptions 
5.1.3.9 and 5.1.3.8), structural 
capabilities of WPs (Assumption 
5.1.3.12). 
C Any waste form C N p1 p2 7.4E-05 Beyond 
Category 2 
Number of WPs. Load-drop rate for the 
crane. Conditional probability that liftheight 
limit is exceeded given a drop. 
6.3.1.9 Drop of a loaded WP with a defective closure weld (GET-09) 
This section considers handling of WPs with defective closure welds, including handling after 
removal of the lids. An unsuccessful attempt to seal a waste package may occur in the CHF, 
DTF, or FHF. Although the specific potential event sequences do not specify closure welds, this 
is implied because waste packages are not fabricated on site and will be inspected for defects 
before use (BSC 2005 [DIRS 171428], Section 6.4). Note that waste packages with defective 
closure welds should not be confused with the defective WPs mentioned in Section 6.3.1.8. 
Only the WPs for which a significant defect in the closure welds has been detected and deemed 
to require remediation are considered in this section. Figure 11 illustrates the logic for the 
categorization calculations. The probabilities of each branch are estimated in Table 26. Some of 
the branch points identified in Figure 11 involve events in areas other than the dry remediation 
area of the DTF, such as transfer cells in the DTF, CHF, or FHF. The categorization calculations 
are presented in Table 27.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 111 April 2005 
Number of 
WPs 
Successful 
WP closure 
Successful 
WP transfer 
WP contains 
CSNF, HLW, or 
naval SNF (and 
no DOE SNF) 
Lift-height limit 
for DOE SNF 
canister 
respected 
DOE SNF 
canister meets 
specifications 
Categorization 
formula 
P(Yes)  1 A. No defect 
C N P(Yes)  1 B. No drop 
P(Yes) = 1 - p3 C. C N p1 p2 (1 - p3) 
P(No) = p1 
P(Yes)  1 D. No breach 
P(No) = p2 P(Yes)  1 
P(Noa) = p3 P(No) = p5 E. C N p1 p2 p3 p5 
P(No) = p4 F. C N p1 p2 p3 p4 
NOTE: a No here indicates that the WP contains DOE SNF. 
Figure 11. GET-09: Logic for Drop of a WP with a Defective Closure Weld 
Table 26. Inputs for Drop of a WP with a Defective Closure Weld 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism 1.1 Section 6.1.4 
N Number of WPs 11,184 Section 4.1.1 
p1 Fraction of WPs that require remediation. 1.0E-01 Assumption 5.1.3.6 
p2 The probability of dropping a WP in the Remediation Facility is 
given by the number of times a WP with defective closure welds 
is transferred by crane after welding (3) times the crane loaddrop 
rate (10-5). 
3E-05 Assumptions 5.2.3.4 and 
5.1.1.10 
p3 The ratio of the number of WPs that contain DOE SNF to the 
total number of WPs. 
0.304 Section 4.1.1 
p4 The conditional probability of exceeding the lift height given a 
drop. 
1.0E-04 Assumption 5.1.1.12 
p5 The probability that the WP contains a defective DOE SNF 
canister that would breach if the WP is dropped from within the 
lift-height limit. The probability that an individual DOE SNF 
canister is defective is 2.3E-04. A codisposal WP could contain 
2 MCOs. The probability p5 is taken to be the probability that a 
codisposal WP containing two DOE SNF canisters contains one 
or more defective DOE SNF canisters: 1  (1  2.3E-04)2. The 
computed probability is conservative for WPs containing 
standardized DOE SNF canisters because such WPs only 
contain one SNF canister. 
4.6E-04 Section 4.1.18, Table 1
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 112 April 2005 
Table 27. Categorization Calculations for Drop of a WP with a Defective Closure Weld 
Event 
ID Contents of WP 
Categorization 
Formula 
Expected 
Number 
of Events Category 
Features Credited in the 
Categorization Calculation 
A 44 BWR 
assemblies, 21 
PWR assemblies, 1 
naval canister, or 5 
HLW canisters 
NA NA No defect Proper weld. 
B 44 BWR 
assemblies, 21 
PWR assemblies, 1 
naval canister, or 5 
HLW canisters 
NA NA No drop Crane reliability. 
C 44 BWR 
assemblies, 21 
PWR assemblies, 1 
naval canister, or 5 
HLW canisters 
CN p1 p2 (1  p3) 2.6E-02 Category 2 Fraction of defective welds, 
Remediation crane load-drop rate. 
D DOE SNF canister NA NA No breach Fraction of defective welds, 
Remediation crane load-drop rate. 
Structural capabilities of the DOE 
SNF canisters (Section 4.1.18). 
Crush pads and lift height limits 
for DOE SNF WPs (Assumption 
5.1.1.52) 
E DOE SNF canister CN p1 p2 p3 p5 5.2E-06 Beyond 
Category 2 
Fraction of defective welds, 
Remediation crane load-drop rate, 
Fraction of DOE SNF canisters, 
Canister defect rate. 
F DOE SNF canister CN p1 p2 p3 p4 1.1E-06 Beyond 
Category 2 
Fraction of defective welds, 
Remediation crane load-drop rate, 
Fraction of DOE SNF canisters, 
Lift-height limit reliability. 
6.3.1.10 Drop or collision of CSNF assemblies during dry remediation activities 
(GET-10) 
This section includes drops and collisions of CSNF assemblies during dry remediation activities 
in the DTF. Similar events that occur during normal handling of assemblies from DPCs are not 
covered here; those are covered in Section 6.3.1.3. Waste may be transferred from defective, 
damaged, or otherwise suspect transportation or transfer casks, MSCs, or WPs. Remediation is 
required for only a small fraction of the total number of assemblies to be emplaced. It is not 
possible to reliably predict the fraction, but this analysis conservatively allows 10 percent to be 
processed in the dry remediation area (Assumption 5.2.3.1). Each assembly must be transferred 
twice: (1) from the defective or suspect container to a basket on a trolley and (2) from the basket 
on the trolley into an MSC, staging rack, or WP. Any subsequent transfers that may take place 
from staging to a WP are not considered here, but are included implicitly in the under normal 
handling operations as part of the uncertainty in numbers of canisters. Some of the transfers are 
performed by the spent fuel transfer machine and others are performed by an overhead crane. 
The same drop rate applies in either case (Assumptions 5.1.1.7 and 5.1.1.10). Figure 12
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 113 April 2005 
illustrates the logic for the categorization calculations. The probabilities of each branch are 
estimated in Table 28. The categorization calculations are presented in Table 29. 
Number of CSNF 
assemblies 
Assembly 
retained during 
transfer 
Assembly collision 
avoided 
Categorization 
formula 
P(Yes)  1 A. No drop 
P(Yes)  1 
C N P(No) = p2 B. C N p2 
P(No) = p1 C. C N p1 
Figure 12. GET-10: Drop or Collision of a CSNF Assembly during Dry Remediation Activities 
Table 28. Inputs for Drop or Collision of CSNF Assemblies during Dry Remediation Activities 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N The number of CSNF assemblies handled in dry remediation is 
10 percent of the total. 
22,100 Assumptions 5.2.1.4 and 
5.2.3.1 
p1 Probability of a drop of a CSNF assembly is given by the 
maximum number of transfers (2) times the drop rate of the 
crane or spent fuel transfer machine (10-5). 
2E-05 Assumptions 5.2.1.1, 
5.1.1.7, and 5.1.1.10 
p2 Probability of a collision of a CSNF assembly is given by the 
maximum number of transfers (2) times assembly-collision rate 
of the crane or spent fuel transfer machine (10-5). 
2E-05 Assumptions 5.2.1.1 and 
5.1.1.8 
Table 29. Categorization of Drop or Collision of CSNF Assemblies during Dry Remediation Activities 
Event 
ID 
Bounding Material at 
Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 1 assembly 
(Assumption 5.2.1.3) 
NA NA No drop Crane and spent fuel transfer 
machine reliability. 
B 1 assembly 
(Assumption 5.2.1.3) 
C N p2 4.9E-01 
collisions 
Category 2 Numbers of assemblies. 
Collision rate. 
C 2 assemblies C N p1 4.9E-01 
drops 
Category 2 Numbers of assemblies. 
Load-drop rate. 
6.3.1.11 Drop of a canister from a crane during WP remediation or dry remediation 
activities in the DTF (GET-11) 
This section considers canister drops during WP remediation or dry remediation activities in the 
DTF, including WPs, transportation or transfer casks, and MSCs. The overhead bridge crane
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 114 April 2005 
transfers standardized DOE SNF canisters, MCOs, HLW canisters, and naval canisters. The 
generalized canister-drop event sequence includes drop of a canister into a WP, staging rack, 
MSC, basket on a trolley, or onto the floor of the transfer cell. 
Canisters taken from a cask in need of remediation may be transferred twice as follows: 
1. From the cask to a basket on a trolley 
2. From the basket to a WP, staging rack, or MSC (as applicable, Assumption 5.2.1.20). 
DPCs taken from a cask in need of remediation will undergo a transfer to the DPC cutting 
machine and another transfer after the lid-cutting operation. Canisters taken from a WP in need 
of remediation will undergo only one transfer because they will go directly from the WP to a 
new WP, staging rack, or MSC (as applicable, Assumption 5.2.1.20). The few subsequent 
transfers that may take place from staging to a WP are not considered here, but are included 
implicitly in the under normal handling operations as part of the uncertainty in numbers of 
canisters. 
Figure 13 illustrates the logic for the categorization calculations. The probabilities of each 
branch are estimated in Table 30. The categorization calculations are presented in Table 31. 
Table 32 covers drops of one canister onto another canister. 
Number of DOE 
SNF, HLW, naval, 
and DPC canisters 
handled 
Canister is a 
DPC, HLW, or 
naval canister 
Crane 
retains 
canister 
Lift-height 
limit for DOE 
SNF canisters 
respected 
DOE SNF 
canister meets 
specifications 
Categorization 
formula 
P(Yes)  1 A. No drop 
P(Yes) = 1 - p1 
P(No) = p2 Breach presumed B. C N ( 1 - p1 ) p2 
C N P(Yes)  1 C. No drop 
P(Yes)  1 D. No breach 
P(Noa) = p1 
P(Yes)  1 
P(No) = p2 P(No) = p4 E. C N p1 p2 p4 
P(No) = p3 F. C N p1 p2 p3 
NOTE: a No here indicates that the canister contains DOE SNF. 
Figure 13. GET-11: Logic for Canister Drop During Dry Remediation or WP Remediation Activities
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 115 April 2005 
Table 30. Inputs for Drop of a Canister During Dry Remediation or WP Remediation Activities 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of DOE, naval, and DPC canisters handled. 2,949 Table 8; Assumption 
5.2.3.1. 
p1 Fraction of canisters that are DOE SNF canisters 1.2E-01 Table 8 
p2 Probability of a crane drop is given by the conservatively 
estimated number of transfers (2) times the crane load-drop 
rate (10-5). 
2.0E-05 See discussion above in 
this section. Assumption 
5.1.1.10 
p3 The conditional probability of exceeding the lift height given a 
drop. 
1.0E-04 Assumption 5.1.1.12 
p4 The probability that a DOE canister is defective and would 
breach if dropped from within the lift-height limit. 
2.3E-04 Section 4.1.18 
Table 31. Categorization Calculations for Canister Drop During Dry Remediation or WP Remediation 
Activities 
Event 
ID 
Bounding 
Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 2 HLW (Table 32, 
Row 1), 1 naval, or 1 
DPC canister (74 BWR 
or 36 PWR 
assemblies, 
Assumption 5.1.1.34) 
NA NA No drop Crane reliability. 
B 2 HLW (Table 32, 
Row 1), 1 naval, or 1 
DPC canister (74 BWR 
or 36 PWR 
assemblies, 
Assumption 5.1.1.34) 
C N (1 - p1) p2 5.7E-02 Category 2 Numbers of canisters. Crane 
load-drop rate. 
C 1 DOE SNF canister NA NA No drop Crane reliability. 
D 1 DOE SNF canister NA NA No breach Numbers of canisters. Crane 
load-drop rate. Structural 
capabilities of canisters. 
E 1 DOE SNF canister C N p1 p2 p4 1.8E-06 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Canister 
defect rate. 
F 1 DOE SNF canister C N p1 p2 p3 7.9E-07 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Crane liftheight 
reliability.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 116 April 2005 
Table 32. Categorization Comments for Canister Drops Involving Two Canisters During Dry Remediation 
or WP Remediation Activities 
Row 
Canister 
Dropped Canister Hit Categorization Comment 
1 HLW HLW Both canisters breach. This event is covered in Table 31, Event B. The 
material at risk is two HLW canisters for this event. This sets the 
bounding material at risk in Table 31, Event B. 
2 HLW Standardized 
DOE SNF 
HLW canister breaches, SNF canister does not breach (Assumptions 
5.1.1.24 and 5.1.1.25). This event is covered in Table 31, Event B. 
3 HLW MCO HLW canister breaches, but the MCO does not breach (Assumptions 
5.1.1.24 and 5.1.1.25). This event is covered in Table 31, Event B. 
4 Standardized 
DOE SNF 
Standardized 
DOE SNF 
Beyond Category 2. Standardized DOE SNF canisters will not breach if 
dropped onto each other (Assumptions 5.1.1.28). 
5 Standardized 
DOE SNF 
MCO This combination is not applicable because standardized DOE SNF 
canisters and MCOs are not shipped together (Table 8) or disposed of 
together (Table 1) and MCOs are not staged (Assumption 5.2.1.20). 
6 Standardized 
DOE SNF 
HLW Rendered Beyond Category 2 by an operational requirement not to 
transfer a standardized DOE SNF canister into or out of a WP if there 
are one or more HLW canisters present in the WP or MSC (Assumption 
5.1.1.23). 
7 MCO Standardized 
DOE SNF 
See Row 5. 
8 MCO MCO Beyond Category 2. MCOs will not breach if dropped onto each other 
(Assumption 5.1.1.28). 
9 MCO HLW Rendered Beyond Category 2 by an operational requirement not to 
transfer a standardized DOE SNF canister into or out of a WP if there 
are one or more HLW canisters present in the WP or MSC (Assumption 
5.1.1.23). 
6.3.1.12 Drop or collision of CSNF assembly transfer/handling equipment onto or 
against CSNF assemblies in the remediation pool (GET-12) 
This section covers drops and collisions of handling equipment used for CSNF assembly 
transfers during wet remediation activities in the DTF remediation pool. Collisions with breach 
are considered Beyond Category 2 because the maximum speed of handling equipment 
movements will be below speeds that could initiate an event sequence upon collision with a 
CSNF assembly (Assumption 5.1.1.54). A handling-equipment drop results in a release. It is 
assumed that no more than 10 percent of fuel assemblies are handled in the wet remediation area 
(Assumption 5.2.3.2). Each assembly may be transferred twice: (1) from the defective or suspect 
container to a basket or rack and (2) from the basket or rack into an MSC. Figure 14 illustrates 
the logic for the categorization calculations. The probabilities of each branch are estimated in 
Table 33. The categorization calculations are presented in Table 34.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 117 April 2005 
Number of 
CSNF 
assemblies 
Handling equipment 
retained during 
assembly transfer 
Categorization 
formula 
P(Yes)  1 A. No drop 
C N 
P(No) = p1 B. C N p1 
Figure 14. GET-12: Logic for Drop of Handling Equipment onto CSNF Assemblies During Wet 
Remediation 
Table 33. Inputs for Drops of Handling Equipment onto CSNF Assemblies During Wet Remediation 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N The number of CSNF assemblies handled in wet remediation is 
10 percent of the total. 
22,100 Assumptions 5.2.1.4 and 
5.2.3.2 
p1 Probability of a drop of a handling equipment is given by the 
maximum number of transfers (2) times the rate of drop or 
collision of handling equipment of the fuel handling machine 
(10-7). 
2E-07 Assumption 5.1.1.9 
Table 34. Categorization Calculations for Drop of Handling Equipment onto CSNF Assemblies During 
Wet Remediation 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 1 assembly NA NA No drop Fuel transfer machine 
reliability. 
B 1 assembly C N p1 4.9E-03 Category 2 Numbers of assemblies. 
Load-drop rate. 
6.3.1.13 Drop of a loaded transportation or transfer cask or MSC in the wet remediation 
area (GET-13) 
DOE casks, transfer casks, or naval casks will not be processed in the DTF remediation pool. 
However, they may be decontaminated in the cask pit. A drop or collision into the CSNF 
assembly staging rack in the pool is prevented by an operational requirement that prohibits 
carrying a cask or MSC over or near the CSNF assembly staging rack in the pool (Assumption 
5.1.5.1). Four transfers are required for each cask that is placed in the pool:
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 118 April 2005 
1. From the trolley to the pit 
2. From the pit to the pool 
3. From the pool to the pit 
4. From the pit to the trolley. 
Four transfers per cask is conservative because not all transportation casks or MSCs are placed in 
the pool. Figure 15 illustrates the logic for the categorization calculations. The probabilities of 
each branch are estimated in Table 35. The categorization calculations are presented in Table 
36. 
Number of drops of 
transportation casks 
or MSCs 
Transportation 
cask or MSC 
contains CSNF, 
naval SNF, or 
DOE HLW 
Lift-height limit 
for DOE SNF 
canister 
respected 
Canister meets 
specifications 
Categorization formula 
P(Yes) = 1 - p1 Breach presumed A. C N ( 1 - p1 ) 
P(Yes)  1 B. No breach 
C N 
P(Yes)  1 
P(No) = p3 C. C N p1 p3 
P(Noa) = p1 
P(No) = p2 D. C N p1 p2 
NOTE: a No here indicates that the cask or MSC contains DOE SNF. 
Figure 15. GET-13: Drop of Transportation Cask or MSC During Wet Remediation
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 119 April 2005 
Table 35. Inputs for Drop of a Transportation Cask or MSC During Wet Remediation 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N The number of dropped transportation casks or MSCs. Ten 
percent of the transportation casks or transfer casks and an 
equal number of MSCs will be unloaded in the pool. 10 percent 
of 13,479 transportation casks gives 1,348 transportation casks. 
Adding an equal number of MSCs gives 2,696. The expected 
number of dropped transportation casks or MSCs is given by 
2,696 times the number of transfers per cask (4) times the 
crane load-drop rate (1E-05 drops/transfer). 
1.08E-01 Assumptions 5.2.3.2, 
5.2.1.10, and 5.1.1.10 
p1 Fraction of casks that are DOE SNF casks (457/13,479). 3.39E-02 Table 8 
p2 The conditional probability of exceeding the lift-height limit given 
that a drop occurred. 
1.0E-04 Assumptions 5.1.1.12 
and 5.1.1.18. 
p3 The probability that one or more of the DOE canisters in the 
cask is defective such that it may breach if dropped from within 
the lift-height limit. The probability that a given canister is 
defective is 2.3E-04. Each DOE cask may contain up to 9 
canisters. The probability that the cask contains one or more 
defective canisters is given by 1  (1  2.3E-04)9. The resulting 
probability is conservative for MCO casks, which only contain 4 
MCOs. 
2.1E-03 Section 4.1.18. Table 8. 
Table 36. Categorization Calculations for Drop of a Transportation Cask or MSC During Wet Remediation 
Event 
ID 
Contents of Cask 
(Material at Risk) 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister. For 
conservatism in the 
consequence 
calculation, it should 
be assumed that the 
drop occurs out of the 
pool. 
C N (1  p1) 1.1E-01 Category 2 Number of transportation 
cask receipts. Fraction that 
are not DOE SNF. Craneload 
drop rate. 
B DOE SNF canisters NA NA No breach Lift height limit respected. 
Canister meets 
specifications. 
C DOE SNF canisters C N p1 p3 8.4E-06 Beyond 
Category 2 
Numbers of DOE SNF casks 
Crane load-drop rate. 
Canister defect rate 
D DOE SNF canisters C N p1 p2 4.0E-07 Beyond 
Category 2 
Numbers of DOE SNF 
canister casks. Crane loaddrop 
rate. Crane lift-height 
reliability.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 120 April 2005 
6.3.1.14 Drop of an empty cask or MSC onto a loaded CSNF assembly cask or MSC or 
basket in the DTF remediation pool (GET-14) 
The potential event under consideration will be prevented by an operational requirement to 
prohibit carrying empty casks or MSCs over loaded casks or baskets in the DTF remediation 
pool (Assumption 5.1.1.50). 
6.3.1.15 Drops or collisions of empty or full canisters for damaged CSNF assemblies 
(empty or full) onto or against a cask or basket in the DTF remediation pool 
(GET-15) 
After a damaged assembly is placed in a single-assembly canister in the DTF remediation pool, 
the canister will be transferred to an MSC or CSNF basket. To account for the case in which the 
canisterized assembly is transferred to a basket and then to an MSC, two transfers per canister 
are used. Figure 16 illustrates the logic for the categorization calculations. The probabilities of 
each branch are estimated in Table 37. The categorization calculations are presented in Table 
38. To avoid a drop or collision involving an empty canister that could lead to a radiological 
release, an operational requirement will prohibit suspending an empty canister above an open 
cask, MSC, or CSNF basket that contains CSNF (Assumption 5.1.1.56). 
Number of 
canisterized CSNF 
assemblies 
Canisterized assembly 
retained during 
transfer Collision avoided 
Categorization 
formula 
P(Yes)  1 A. No collision 
P(Yes)  1 
C N P(No) = p2 B. C N p2 
P(No) = p1 C. C N p1 
Figure 16. GET-15: Logic for Drop or Collision of a Canisterized CSNF Assembly In the DTF 
Remediation Pool
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 121 April 2005 
Table 37. Inputs for Drop or Collision of a Canisterized CSNF Assembly In the DTF Remediation Pool 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N No more than 1 percent of spent fuel assemblies will arrive so 
severely damaged after arrival that they must be canisterized. 
2,210 Assumptions 5.2.1.4 and 
5.2.1.14 
p1 Probability of a drop of a CSNF assembly is given by the 
maximum number of transfers (2) times the assembly-drop rate 
of the fuel handling machine (10-5). 
2E-05 Assumption 5.1.1.7 
p2 Probability of a collision of a CSNF assembly is given by the 
maximum number of transfers (2) times assembly-collision rate 
of the fuel handling machine (10-5). 
2E-05 Assumption 5.1.1.8 
Table 38. Categorization Calculations for Drop or Collision of a Canisterized CSNF Assembly In the DTF 
Remediation Pool 
Event 
ID 
Bounding Material at 
Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 1 assembly 
(Assumption 5.2.1.3) 
NA NA No collision Fuel transfer machine 
reliability. 
B 1 assembly 
(Assumption 5.2.1.3) 
C N p2 4.9E-02 
collisions 
Category 2 Numbers of assemblies. 
Collision rate. 
C 2 assemblies C N p1 4.9E-02 
drops 
Category 2 Numbers of assemblies. 
Load-drop rate. 
6.3.1.16 Drops or collisions involving CSNF assemblies in the pool (GET-16) 
Each CSNF assembly that is transferred in the remediation pool in the DTF is staged prior to 
being loaded into another cask, so that there are two transfers per assembly. A dropped assembly 
could hit another assembly, with the result that two assemblies may be affected; for collisions, 
only one assembly is affected (Assumption 5.2.1.3). Figure 17 illustrates the logic for the 
categorization calculations. The probabilities of each branch are estimated in Table 39. The 
categorization calculations are presented in Table 40.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 122 April 2005 
Number of CSNF 
assemblies 
Assembly retained 
during transfer 
Collision 
avoided 
Categorization 
formula 
P(Yes)  1 A. No collision 
P(Yes)  1 
C N P(No) = p2 B. C N p2 
P(No) = p1 C. C N p1 
Figure 17. GET-16: Logic for Drop or Collision of a CSNF Assembly in the DTF Remediation Pool 
Table 39. Inputs for Drop or Collision of a CSNF Assembly in the DTF Remediation Pool 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N The number of CSNF assemblies handled in the pool is 10 
percent of the total. 
22,100 Assumptions 5.2.1.4 and 
5.2.3.2 
p1 Probability of a drop of a CSNF assembly is given by the 
maximum number of transfers (2) times the assembly-drop rate 
of the fuel handling machine (10-5). 
2E-05 Assumption 5.1.1.7 
p2 Probability of a collision of a CSNF assembly is given by the 
maximum number of transfers (2) times assembly-collision rate 
of the fuel handling machine (10-5). 
2E-05 Assumption 5.1.1.8 
Table 40. Categorization Calculations for Drop or Collision of a CSNF Assembly in the DTF Remediation 
Pool 
Event 
ID 
Bounding Material at 
Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 1 CSNF assembly NA NA No collision Fuel transfer machine 
reliability. 
B 1 CSNF assembly C N p2 4.9E-01 
collisions 
Category 2 Numbers of assemblies. 
Collision rate. 
C 2 CSNF assemblies C N p1 4.9E-01 
drops 
Category 2 Numbers of assemblies. 
Load-drop rate. 
6.3.1.17 Drop of a filled CSNF basket from the fuel handling machine into the pool 
(GET-17) 
Given that each fuel element handled in the remediation pool in the DTF may take a trip to and 
from the staging rack, there are at most two transfers per basket load. It is conservative for 
categorization to use the lowest number of assemblies per basket load; therefore the number used 
is nine assemblies per basket load (Assumption 5.2.3.3). Figure 18 illustrates the logic for the
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 123 April 2005 
categorization calculations. The probabilities of each branch are estimated in Table 41. The 
categorization calculations are presented in Table 42. The capacity of the basket, and therefore 
the material at risk (Assumption 5.1.5.7), is assumed to be sixteen PWR assemblies or nine BWR 
assemblies (Assumption 5.2.3.3). 
Number of SNF 
baskets handled 
Load retained 
during transfer 
Categorization 
formula 
P(Yes)  1 A. No drop 
C N 
P(No) = p1 B. C N p1 
Figure 18. GET-17: Logic for Drop of a CSNF Assembly Basket from the Fuel Handling Machine Into the 
Pool 
Table 41. Inputs for Drop of a CSNF Assembly Basket in the Pool 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Ten percent of CSNF assemblies are assumed to be handled in 
the pool. Each basket is assumed to hold 9 assemblies, which 
is conservative for categorization. 
2456 Assumptions 5.2.1.4, 
5.2.3.2, and 5.2.3.3 
p1 Probability of a drop of a CSNF assembly basket is given by the 
maximum number of transfers (2) times the load-drop rate of 
the spent fuel transfer machine (10-5). 
2E-05 Assumption 5.1.1.7 
Table 42. Categorization Calculations for Drop of a CSNF Assembly Basket in the Pool 
Event 
ID 
Bounding Material at 
Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A NA NA NA No drop Fuel transfer machine 
reliability 
B 9 PWR assemblies or 
16 BWR assemblies 
C N p1 5.4E-02 Category 2 Numbers of assemblies. Drop 
rate 
6.3.1.18 Drop or collision of handling equipment into or against an opened container 
filled with CSNF during dry remediation (GET-18) 
This section addresses drop or and collision of handling equipment during dry remediation 
activities in the DTF. Collisions with breach are considered Beyond Category 2 because the 
maximum speed of handling equipment movements will be below speeds that could initiate an 
event sequence upon collision with a CSNF assembly (Assumption 5.1.1.54). With the
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 124 April 2005 
possibility of staging, each assembly may be transferred up to two times. Figure 19 illustrates 
the logic for the categorization calculations. The probabilities of each branch are estimated in 
Table 43. The categorization calculations are presented in Table 44. 
Number of CSNF 
assemblies 
Handling equipment 
retained before and after 
assembly transfer 
Categorization 
formula 
P(Yes)  1 A. No drop 
C N 
P(No) = p1 B. C N p1 
Figure 19. GET-18: Logic for Drop of Handling Equipment on CSNF Assemblies in Dry Remediation 
Table 43. Inputs for Drop of Handling Equipment on CSNF Assemblies in Dry Remediation 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Ten percent of 221,000 assemblies will be handled in dry 
remediation. 
22,100 Assumptions 5.2.3.1 and 
5.2.1.4 
p1 Probability of a load drop is given by the number of 
opportunities for a drop (2) times the equipment-drop rate for 
the spent fuel transfer machine (10-7). 
2E-07 See discussion above in 
this section. Assumption 
5.1.1.9. 
Table 44. Categorization Calculations for Drop of Handling Equipment on CSNF Assemblies in Dry 
Remediation 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 1 assembly 
(Assumption 5.2.1.11) 
NA NA No drop Spent fuel transfer machine 
equipment drop rate. 
B 1 assembly 
(Assumption 5.2.1.11) 
C N p1 4.9E-03 Category 2 Spent fuel transfer machine 
equipment drop rate. 
6.3.1.19 Drop of handling equipment into an open WP loaded with DOE canisters or a 
naval canister during dry remediation activities (GET-19) 
Due to the possibility of staging, a canister may be transferred twice by crane: once to move it 
from the WP to the staging rack, and once to move it from the staging rack to a new WP or 
MSC. For MCOs and naval canisters, which will not be staged (Assumptions 5.2.1.2 and 
5.2.1.20), allowing two transfers per canister is conservative. For each transfer during dry 
remediation activities in the DTF, there are two opportunities for equipment drop. Figure 20
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 125 April 2005 
illustrates the logic for the categorization calculations. The probabilities of each branch are 
estimated in Table 45. The categorization calculations are presented in Table 46. 
Number of DOE 
SNF, HLW, and 
naval SNF 
canisters to 
remediation 
Canister is a 
DOE HLW or 
naval canister 
Handling 
equipment 
retained 
Lift-height limit 
above DOE SNF 
canisters respected 
DOE SNF 
canister meets 
specifications 
Categorization 
formula 
P(Yes)  1 A. No drop 
P(Yes) = 1 - p1 
P(No) = p2 Breach presumed B. C N ( 1 - p1 ) p2 
C N 
P(Yes)  1 C. No drop 
P(Yes)  1 D. No breach 
P(Noa) = p1 
P(Yes)  1 
P(No) = p2 P(No) = p4 E. C N p1 p2 p4 
P(No) = p3 F. C N p1 p2 p3 
NOTE: a No here indicates that the canister contains DOE SNF. 
Figure 20. GET-19: Logic for Handling-Equipment Drop onto a Canister During Dry Remediation 
Table 45. Probabilities for Handling-Equipment Drop onto a Canister in Dry Remediation 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of DOE and naval canisters handled in the 
Remediation Facility. 
1,998 Table 8, Assumption 
5.2.3.1 
p1 Fraction of canisters that are DOE SNF canisters 1.8E-01 Table 8 
p2 Probability of a handling-equipment drop is given by the 
maximum number of transfers (2) times the cranes handlingequipment 
drop rate per transfer (10-5). 
2E-05 See discussion above in 
this section. Assumption 
5.1.1.11. 
p3 The conditional probability of exceeding the lift height given a 
drop of handling equipment. 
1E-04 Assumption 5.1.1.12 and 
5.1.1.31. 
p4 The probability that a DOE SNF canister is defective and would 
breach if equipment is dropped from within the lift-height limit. 
2.3E-04 Section 4.1.18. 
Assumption 5.1.1.31.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 126 April 2005 
Table 46. Categorization of Handling-Equipment Drop onto a Canister in Dry Remediation 
Event 
ID 
Canister Affected 
(Material at Risk) 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A HLW or naval 
canister 
NA NA No drop Crane reliability. 
B HLW or naval 
canister 
C N (1  p1) p2 3.6E-02 Category 2 Numbers of canisters. Crane 
load-drop rate. 
C DOE SNF canister NA NA No drop Crane reliability. 
D DOE SNF canister NA NA No breach Numbers of canisters. Crane 
load-drop rate. 
E DOE SNF canister C N p1 p2 p4 1.8E-06 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Canister 
defect rate. 
F DOE SNF canister C N p1 p2 p3 7.9E-07 Beyond 
Category 2 
Numbers of canisters. Crane 
load-drop rate. Crane liftheight 
reliability. 
6.3.1.20 Drop or collision of the severed lid back onto or against the open DPC from the 
ceiling-mounted manipulator or overhead crane after the completion of the 
DPC lid-cutting (GET-20) 
This section addresses the impact of the DPC lid against CSNF in the open DPC after the DPC 
lid cutting operation in the DTF. Because the lid must enter from the top, only collisions 
resulting from drops are considered. Figure 21 illustrates the logic for the categorization 
calculations. The probabilities of each branch are estimated in Table 47. The categorization 
calculations are presented in Table 48. 
Number of DPCs 
opened 
Lid retained during 
removal 
Categorization 
formula 
P(Yes)  1 A. No drop 
C N 
P(No) = p1 B. C N p1 
Figure 21. GET-20: Logic for Drop of Severed Lid Into an Opened DPC
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 127 April 2005 
Table 47. Inputs for Drop of Severed Lid Into an Opened DPC 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N The number of DPCs is conservatively assumed to be 9,508 
(Assumption 5.2.1.7), which implies that all CSNF assemblies 
are received in DPCs. 
9,508 Assumption 5.2.1.7 
p1 There is one lid transfer for each DPC. Probability of a load 
drop is given by the number of opportunities for a drop (1) times 
the crane load-drop rate per transfer (10-5). 
1E-05 Assumption 5.1.1.10 
Table 48. Categorization Calculations for Drop of Severed Lid Into an Opened DPC 
Event 
ID Material at Risk 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation 
or to Prevent Exposure 
A 74 BWR assemblies or 
36 PWR assemblies 
(Assumption 5.1.1.34). 
NA NA No drop Crane reliability. 
B 74 BWR assemblies or 
36 PWR assemblies 
(Assumption 5.1.1.34). 
C N p1 1.0E-01 Category 2 Crane load-drop rate. 
6.3.1.21 Crane-load collision (GET-21) 
This section considers collisions suffered by MSCs, transportation casks, transfer casks, 
canisters, and waste packages during transfer by crane. The collisions may take place in the 
CWPRB, the CHF, the DTF, or the FHF, as applicable. Collisions at speeds that could cause a 
breach of the cask, canister, or waste package involved in the lift will be prevented by design 
(Assumption 5.1.1.19). A special kind of collision is an attempt to move the load horizontally 
before it is lifted far enough to allow unimpeded horizontal movement; an example is an attempt 
to horizontally move a WP during a transfer from a WP from a loading pit in the CHF before the 
WP has been entirely removed from the pit. A design requirement will ensure that such 
collisions do not result in an event sequence (Assumption 5.1.1.20). 
6.3.1.22 Trolley collision (GET-22) 
This section considers collisions involving trolleys carrying transportation or transfer casks, 
MSCs, or waste packages. The collisions may take place in the CHF, the DTF, or the FHF. 
Collisions of trolleys at speeds that could cause the trolley to drop its load will be prevented by 
design (Assumption 5.1.1.61). 
6.3.1.23 WP Emplacement Gantry collision (GET-23) 
Collisions involving WPs carried in the emplacement drift by the WP Emplacement Gantry that 
could cause a waste-package breach will be prevented by design (Assumptions 5.1.8.7).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 128 April 2005 
6.3.1.24 WP Emplacement Gantry drop (GET-24) 
This section considers drops of waste packages during transfer by the WP Emplacement Gantry 
in the emplacement drift. Each waste package undergoes one trip into the emplacement drift, 
carried by the Emplacement Gantry. Figure 22 illustrates the logic for the categorization 
calculations. The probabilities of each branch of the event tree are estimated in Table 49. The 
categorization calculations are presented in Table 50. 
Bounding number 
of items 
transferred Drop avoided 
Lift height limit 
respected 
Categorization 
formula 
P(Yes)  1 A. No drop 
C N P(Yes)  1 B. No breach 
P(No) = p1 
P(No) = p2 C. C N p1 p2 
Figure 22. GET-24: Logic for Emplacement Gantry Drops 
Table 49. Inputs for Drops of a Sealed WP from an Emplacement Gantry 
Item Description and Calculation (if applicable) Value Cross Reference 
C Factor of conservatism. 1.1 Section 6.1.4 
N Number of WPs. 11,184 Section 4.1.1 
p1 The probability of a drop is given by the maximum number of 
times each WP is transferred by emplacement gantry (1) times 
the drop rate (1.E-05). 
1.E-05 Assumption 5.1.8.1 
p2 A design requirement limits the conditional probability of having 
exceeded a specified height limit given that a drop has 
occurred. 
1.E-04 Assumptions 5.1.3.8 and 
5.1.8.10
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 129 April 2005 
Table 50. Categorization Calculations for Drop of a Sealed WP from an Emplacement Gantry 
Event 
ID 
Contents of 
WP 
Categorization 
Formula 
Expected 
Number of 
Events Category 
Features Credited in the 
Categorization Calculation or to 
Prevent Exposure 
A Any waste form NA NA No collision Load-drop rate 
B Any waste form NA NA No breach Number of WPs. Load-drop rate. 
Speed limit, structural capabilities of 
WPs. 
C Any waste form C N p1 p2 1.2 E-05 Beyond 
Category 2 
Number of WPs. Load-drop rate. 
Conditional probability of having 
exceeded the height limit given that a 
drop occurred. 
6.3.1.25 Loss of confinement zone due to ventilation system malfunction or other breach 
of a confinement barrier leading to a release of airborne radioactive 
contamination 
Primary ventilation confinement is credited in two of the event sequences in Section 6.3.1.3 to 
mitigate doses after a drop or collision involving a CSNF assembly. Confinement is not credited 
in other event sequences. With appropriate operating procedures in place, a loss of confinement 
during otherwise normal operations in the CHF, DTF, FHF, or subsurface does not have the 
potential to expose individuals to significant amounts of radioactivity (Assumption 5.1.1.59). 
6.3.1.26 Overheating of SNF or HLW due to a loss of HVAC 
If ventilation is lost in areas of the CHF, DTF, of FHF where DOE or naval canisters are 
handled, no radiological release will occur from the canisters because containment within the 
canisters is maintained. Design and operational requirements are assumed to ensure that the 
thermal response of areas of the DTF or FHF where CSNF assemblies are handled or staged is 
such that a loss of HVAC would not cause radiological releases in excess of those considered in 
the consequence analysis for normal operations (Assumptions 5.1.2.4 and 5.1.1.45).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 130 April 2005 
6.3.2 CWPRB: Transportation Cask Buffer Area 
A description of the operations in this area and a listing of the hazards and potential events is 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.1). 
6.3.2.1 Collision/Crushing 
6.3.2.1.1 Overturning or collision of a site prime mover moving an LWT or an OWT 
trailer holding a transportation cask (with impact limiters and personnel 
barrier installed) 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
specified in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, an overturning or collision would 
not breach a transportation cask. 
6.3.2.1.2 Derailment, overturning, or collision involving a site prime mover moving an 
offsite railcar holding a transportation cask (with impact limiters and 
personnel barrier installed) followed by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning or 
collision would not breach a transportation cask. 
6.3.2.1.3 Collision involving a forklift and a cask on a railcar or an LWT or an OWT 
trailer (with or without impact limiters and personnel barrier installed) 
Operational requirements are assumed to ensure that forklifts will not be operated in a manner 
that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.2.1.4 Collision involving a mobile elevated platform and a cask on a railcar or an 
LWT or an OWT trailer (with or without impact limiters and personnel 
barrier installed) 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.2.1.5 Drop of a transportation cask and its support skid (with impact limiters and 
personnel barrier installed) from the cask receipt and return area overhead 
crane during transfer to an SRTC 
Transportation casks with impact limiters are designed and tested to withstand, without 
breaching, a 30-ft (9 m) drop onto an unyielding surface (Section 4.2.1). A design requirement 
will ensure that casks with impact limiters installed cannot be lifted higher than 30 ft above the 
floor (Assumption 5.1.9.1). Therefore, a drop of a transportation cask, with the impact limiters 
in place, will not lead to a breach or release of radiological materials.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 131 April 2005 
6.3.2.1.6 Drop or collision of a transportation cask and a support skid (with impact 
limiters and personnel barrier installed) from cask receipt and return area 
overhead crane onto or against a sharp object during transfer to an SRTC 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.2.1.7 Drop of a transportation cask with impact limiters and personnel barrier 
removed (including the naval SNF cask or a transportation cask carrying a 
horizontal DPC not going to SNF Aging System) from the cask receipt and 
return area overhead crane during transfer to an SRTC 
This event is included in Section 6.3.1.1. 
6.3.2.1.8 Drop or collision of a transportation cask with impact limiters and personnel 
barrier removed (including the naval SNF cask or a transportation cask 
carrying a horizontal DPC not going to SNF Aging System) from the cask 
receipt and return area overhead crane onto or against a sharp object during 
transfer to an SRTC 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.2.1.9 Drop of a transportation cask containing a horizontal DPC (with impact 
limiters and personnel barrier removed) from the cask receipt and return area 
overhead crane during transfer to a horizontal cask transfer trailer (for 
subsequent emplacement in a HAM) 
This event is included in Section 6.3.1.1. 
6.3.2.1.10 Drop or collision of a transportation cask containing a horizontal DPC (with 
impact limiters and personnel barrier removed) from the cask receipt and 
return area overhead crane onto or against a sharp object during transfer to a 
horizontal cask transfer trailer (for subsequent emplacement in a HAM) 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 132 April 2005 
6.3.2.1.11 Slapdown of a naval transportation cask or a transportation cask carrying a 
horizontal DPC (or other cask requiring removal of impact limiters prior to 
transfer) from the cask receipt and return area overhead crane back onto the 
railcar (forward slapdown) or the ground or site prime mover (backward 
slapdown) during the upending of the cask to a vertical orientation from a 
horizontal orientation during cask removal from the offsite railcar or other 
transport 
This potential event is covered in Section 6.3.1.1. 
6.3.2.1.12 Slapdown of a naval transportation cask (or other cask requiring removal of 
impact limiters prior to transfer) from the cask receipt and return area 
overhead crane onto the SRTC (forward slapdown) or the ground or SRTC 
tractor (backward slapdown) during the downending of the cask from a 
vertical to a horizontal orientation after cask removal from the offsite railcar 
or other transport 
This potential event is covered in Section 6.3.1.1. 
6.3.2.1.13 Slapdown of a transportation cask holding a horizontal DPC (with impact 
limiters removed) from the cask receipt and return area overhead crane onto 
the horizontal cask transfer trailer or the site prime mover (forward 
slapdown) or the ground (backward slapdown) during the downending of the 
cask from a vertical to a horizontal orientation after cask removal from the 
offsite railcar or other transport 
This potential event is covered in Section 6.3.1.1. 
6.3.2.1.14 Overturning or collision involving the site prime mover pulling a horizontal 
cask transfer trailer holding a transportation cask (without impact limiters) 
containing a horizontal DPC at the TCRRF or departing the TCRRF for the 
HAM. 
Nuclear safety design approaches S.23, S.24, S.25, and S.26 (Section 4.1.11) address this 
potential event sequence. 
6.3.2.1.15 Runaway of a site prime mover pulling a horizontal cask transfer trailer 
holding a transportation cask (with no impact limiters) containing a horizontal 
DPC 
Nuclear safety design approach S.26 (Section 4.1.11) addresses this potential event sequence. 
6.3.2.1.16 Drop or collision of handling equipment onto or against a transportation cask 
(with impact limiters and personnel barrier installed) 
Operational requirements will ensure that drops or collisions involving handling equipment 
associated with the transfer of the transportation cask will not breach the cask (Assumption 
5.1.1.30).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 133 April 2005 
6.3.2.1.17 Drop or collision of handling equipment onto or against a transportation cask 
(without impact limiters or personnel barriers installed) 
Operational requirements will ensure that drops and collisions involving the handling equipment 
associated with the transfer of the transportation cask will not breach the cask (Assumption 
5.1.1.30). 
6.3.2.1.18 Drop or collision of heavy loads from the maintenance crane onto or against a 
transportation cask (with or without impact limiters or personnel barriers 
installed). 
An operational requirement will ensure that heavy loads that could potentially initiate an event 
sequence if dropped or collided onto or against a cask will not be lifted over or near a 
transportation cask, except as needed for cask preparation and transfer operations (Assumption 
5.1.1.33). 
6.3.2.1.19 Derailment of the SRTC positioner moving an SRTC holding a transportation 
cask (with impact limiters and personnel barriers installed) resulting in an 
SRTC collision or derailment followed by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning or 
collision would not breach a transportation cask. 
6.3.2.1.20 Derailment of the SRTC positioner moving an SRTC holding a transportation 
cask (with impact limiters and personnel barrier installed) due to a 
malfunction of the turntable in the TCBA, resulting in an SRTC collision or 
derailment followed by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning or 
collision would not breach a transportation cask. 
6.3.2.1.21 Roll-off and/or derailment of an SRTC holding a transportation cask (with 
impact limiters and personnel barrier installed) from the SRTC positioner 
followed by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, this potential event would not 
breach a transportation cask.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 134 April 2005 
6.3.2.1.22 Collision of an SRTC tractor and an SRTC holding a transportation cask 
(with impact limiters and personnel barrier installed) 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, this potential event would not 
breach a transportation cask. 
6.3.2.1.23 Derailment or collision involving an SRTC holding a transportation cask (with 
impact limiters and personnel barrier installed) being pushed or pulled by an 
SRTC tractor followed by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, this potential event would not 
breach a transportation cask. 
6.3.2.1.24 An SRTC carrying a transportation cask (with impact limiters installed) from 
the CWPRB to the TCBA, the DTF, or the CHF is pushed by the SRTC 
tractor into the SRTC positioner trench 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, this potential event would not 
breach a transportation cask. 
6.3.2.1.25 Drop of a transfer cask containing a horizontal DPC (with impact limiters 
removed) from the cask receipt and return area overhead crane during 
transfer from a horizontal cask transfer trailer (after retrieval from a HAM) 
to an SRTC for processing in the DTF 
This event is included in Section 6.3.1.1. 
6.3.2.1.26 Drop or collision of a transfer cask containing a horizontal DPC (with impact 
limiters removed) from the cask receipt and return area overhead crane onto 
or against a sharp object during transfer from a horizontal cask transfer 
trailer (after retrieval from a HAM) to an SRTC for processing in the DTF 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 135 April 2005 
6.3.2.1.27 Slapdown of a transfer cask holding a horizontal DPC (without impact 
limiters) from the cask receipt and return area overhead crane back onto the 
horizontal cask transfer trailer or the site prime mover (forward slapdown) or 
the ground (backward slapdown) during the upending of the cask to a vertical 
orientation from a horizontal orientation during the transfer of the cask from 
the horizontal cask transfer trailer to an SRTC 
This potential event is covered in Section 6.3.1.1. 
6.3.2.1.28 Slapdown of a transfer cask holding a horizontal DPC (without impact 
limiters) from the cask receipt and return area overhead crane onto an SRTC 
or SRTC Tractor (forward slapdown) or the ground (backward slapdown) 
during the downending of the cask to a vertical orientation from a horizontal 
orientation after removal from the horizontal cask transfer trailer 
This potential event is covered in Section 6.3.1.1. 
6.3.2.1.29 Overturning or collision involving the site prime mover pulling a horizontal 
cask transfer trailer holding a transfer cask (without impact limiters) 
containing a horizontal DPC in transit to, or at, the TCRRF 
Nuclear safety design approaches S.23, S.24, S.25, and S.26 (Section 4.1.11) address this 
potential event sequence. 
6.3.2.1.30 Runaway of a site prime mover pulling a horizontal cask transfer trailer 
holding a transfer cask (with no impact limiters) containing a horizontal DPC 
Nuclear safety design approach S.26 (Section 4.1.11) addresses this potential event sequence. 
6.3.2.2 Chemical Contamination/Flooding 
6.3.2.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed cask (BSC 2005 [DIRS 171428], Section 
6.6.1), this potential event cannot occur unless an event sequence leads to exposure of SNF to 
air. The consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.2.3 Explosion/Implosion 
6.3.2.3.1 Hydrogen explosion involving batteries on a forklift 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 136 April 2005 
6.3.2.3.2 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51). 
6.3.2.3.3 Hydrogen explosion involving batteries on a site prime mover 
The waste is protected by casks while in the presence of batteries for heavy equipment. The 
magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51). 
6.3.2.4 Fire, Thermal 
6.3.2.4.1 Fire/explosion (battery/electrical fire) involving a site prime mover moving an 
LWT or an OWT trailer holding a transportation cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.2 Fire/explosion (battery/electrical fire) involving a site prime mover moving a 
railroad car holding a rail transportation cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.3 Fire/explosion (battery/electrical fire) involving a site prime mover pulling or 
pushing a horizontal cask transfer trailer holding a transportation cask 
containing a horizontal DPC (at the TCRRF or in transit to the HAM) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.4 Fire/explosion (battery/electrical fire) involving a site prime mover pulling or 
pushing a horizontal cask transfer trailer holding a transfer cask containing a 
horizontal DPC (at the TCRRF or in transit from the HAM) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.5 Diesel fuel fire/explosion involving an SRTC tractor pushing or pulling an 
SRTC holding a transportation cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 137 April 2005 
6.3.2.4.6 Electrical fire involving the cask receipt and return area overhead crane 
handling equipment or other electrical equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.7 Electrical fire involving the SRTC positioner holding an SRTC loaded with a 
transportation cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.8 Electrical fire involving the turntable carrying the SRTC positioner holding 
an SRTC loaded with a transportation cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.9 Fire/Explosion (battery/electrical fire) associated with a forklift 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.10 Fire/Explosion (battery/electrical fire) associated with a mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.11 Transient combustible fire in CWPRB or the TCBA 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.2.4.12 Cask overheating due to solar insolation while on an offsite transport or an 
SRTC 
Transportation casks must be evaluated under normal conditions of transport and hypothetical 
accident conditions, which include exposure to insolation under normal conditions and fires 
under hypothetical accident conditions as described in Section 4.2.1. The normal and 
hypothetical accident conditions bound insolation on site. Therefore, the incidence of solar 
radiation on transportation casks will not initiate an event sequence.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 138 April 2005 
6.3.2.5 Radiation 
6.3.2.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. Consequence analyses will evaluate this hazard for 
event sequences and normal operations, as applicable. 
6.3.2.5.2 Radiation-induced damage to a facility SSC 
Radiation is one of the environmental conditions to which SSCs will be exposed, similar to 
vibration, humidity, load-imposed stresses, temperature fluctuations, etc. To the extent that 
radiation-induced failures of an SSC could lead to a radiological exposure, such failures are 
considered as part of the overall failure rate that is used to categorize event sequences. Where 
design requirements require prevention of radiological exposure, radiation is one of the 
environmental conditions that the design must account for. Therefore, radiation-induced damage 
to a facility SSC is not a separate event for the purposes of categorization. 
6.3.2.6 Fissile 
6.3.2.6.1 Criticality associated with a transportation cask collision, drop, or slapdown 
(involving a crane) and a rearrangement of the cask internals 
A criticality in the TCRRF or the TCBA is not credible because design requirements and waste 
acceptance criteria will ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.2.6.2 Criticality associated with an offsite railcar collision or derailment (holding a 
transportation cask) followed by a load tipover or fall and a rearrangement of 
the cask internals 
This potential event is covered by the discussion in Section 6.3.2.6.1. 
6.3.2.6.3 Criticality associated with a collision or overturning of an LWT or an OWT 
trailer (holding a transportation cask) and a rearrangement of the cask 
internals 
This potential event is covered by the discussion in Section 6.3.2.6.1. 
6.3.2.6.4 Criticality associated with an SRTC collision or derailment (holding a 
transportation cask) followed by a load tipover or fall and a rearrangement of 
the cask internals. 
This potential event is covered by the discussion in Section 6.3.2.6.1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 139 April 2005 
6.3.2.6.5 Criticality associated with an SRTC positioner collision or derailment 
(carrying an SRTC holding a transportation cask) followed by a load tipover 
or fall and rearrangement of the cask internals 
This potential event is covered by the discussion in Section 6.3.2.6.1. 
6.3.2.6.6 Criticality associated with a transportation cask (holding a horizontal DPC) 
collision or derailment (involving a horizontal cask transfer trailer or railcar) 
followed by a load tipover or fall and a rearrangement of the cask internals. 
A criticality is not credible because design requirements and waste acceptance criteria will 
ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.2.6.7 Criticality associated with a transportation cask (holding a horizontal DPC) 
drop or slapdown from the cask receipt and return area overhead crane and a 
rearrangement of the cask internals. 
A criticality is not credible because design requirements and waste acceptance criteria will 
ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.2.6.8 Criticality associated with a transfer cask (holding a horizontal DPC) collision 
or derailment (involving a horizontal cask transfer trailer or an SRTC) 
followed by a load tipover or fall and a rearrangement of the cask internals. 
A criticality in a transfer cask is not credible because a design requirement will ensure that 
transfer casks remain subcritical even with reconfiguration of the fissile material due to a drop 
and optimal moderation (Assumption 5.1.1.4). 
6.3.2.6.9 Criticality associated with a transfer cask (holding a horizontal DPC) drop or 
slapdown from the cask receipt and return area overhead crane and a 
rearrangement of the cask internals. 
A criticality in a transfer cask is not credible because a design requirement will ensure that 
transfer casks remain subcritical even with reconfiguration of the fissile material due to a drop 
and optimal moderation (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 140 April 2005 
6.3.3 CHF 
A description of the operations in this facility and a listing of the hazards and potential events is 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.2). SRTCs, LWT trailers, or OWT trailers carry transportation casks with impact 
limiters installed into the vestibule (BSC 2005 [DIRS 171428] Section 6.6.2.1). 
6.3.3.1 Entrance Vestibule, Tools/Parts Storage Room 
6.3.3.1.1 Collision/Crushing 
6.3.3.1.1.1 SRTC derailment, overturning, or collision involving a loaded cask followed 
by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the drops that could occur 
during cask handling at the repository. Consequently, a derailment, overturning, or collision 
would not breach a transportation cask. 
6.3.3.1.1.2 Overturning or collision involving an LWT trailer or OWT trailer holding a 
cask 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask. 
6.3.3.1.1.3 SRTC derailment, overturning, or collision involving a loaded MSC followed 
by a load tipover or fall 
A design requirement is assumed to ensure that the SRTC will not derail and the MSC will not 
fall off the SRTC (Assumption 5.1.1.35). Because the SRTC remains upright there is no threat 
to the integrity of the cask. 
6.3.3.1.1.4 Collision of an SRTC, an LWT trailer, or OWT trailer carrying a loaded 
cask with the entrance vestibule doors, the tool/parts storage room doors, or 
the canister transfer cell shield doors 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 141 April 2005 
6.3.3.1.1.5 The entrance vestibule doors, tool/parts storage room doors, or the canister 
transfer cell shield doors close on an SRTC, an LWT trailer, or an OWT 
trailer carrying a loaded cask 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask. 
6.3.3.1.1.6 Collision of an SRTC carrying a loaded MSC with the entrance vestibule 
doors, tool/parts storage room doors, or the canister transfer cell shield doors 
A design or operational requirement is assumed to ensure that a collision with the SRTC will not 
overturn the SRTC or cause it to drop its load (Assumption 5.1.1.38). Because the SRTC 
remains upright there is no threat to the integrity of the MSC. 
6.3.3.1.1.7 The entrance vestibule doors, tool/parts storage room doors, or the canister 
transfer cell shield doors close on an SRTC carrying a loaded MSC 
A design requirement is assumed to ensure that closure of the entrance vestibule doors, tool/parts 
storage room doors, or the canister transfer cell shield doors onto an SRTC would not overturn 
the SRTC or cause it to drop its load (Assumption 5.1.1.13). Because the SRTC remains upright 
there is no threat to the integrity of the cask. 
6.3.3.1.1.8 Collision of a mobile elevated platform with a cask during removal of 
personnel barriers and impact limiters or during survey activities 
Operational requirements are assumed to ensure that the mobile platform will not be operated in 
a manner that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.3.1.1.9 Drop or collision of personnel barriers or impact limiters from the entrance 
vestibule overhead crane onto or against a cask 
Operational requirements will ensure that equipment associated with cask preparation and 
handling will not breach the cask (Assumption 5.1.1.30). 
6.3.3.1.1.10 Collision between a forklift and a cask on an SRTC, an LWT trailer or an 
OWT trailer or the conveyance holding the cask 
Operational requirements are assumed to ensure that the forklifts operating in the CHF will not 
be operated in a manner that could breach a loaded cask (Assumption 5.1.1.41). 
6.3.3.1.1.11 Collision between a mobile elevated platform and a cask on an SRTC, an 
LWT trailer or an OWT trailer or the conveyance holding the cask 
Operational requirements are assumed to ensure that the mobile platform will not be operated in 
a manner that could breach a transportation cask (Assumption 5.1.1.41).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 142 April 2005 
6.3.3.1.1.12 Collision between a forklift and an MSC on an SRTC or the SRTC holding 
the cask 
Operational requirements are assumed to ensure that the forklifts operating in the CHF will not 
be operated in a manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.3.1.1.13 Collision between a mobile elevated platform and an MSC on an SRTC or 
the SRTC holding the MSC 
Operational requirements are assumed to ensure that the mobile platform will not be operated in 
a manner that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.3.1.1.14 Drop or collision of equipment from the entrance vestibule overhead bridge 
crane (including handling equipment for personnel barrier, impact limiters, 
etc.) onto or against a cask or MSC 
Operational requirements are assumed to ensure that a drop or collision of handling equipment 
onto a transportation cask without impact limiters or onto an MSC would not breach the cask 
(Assumption 5.1.1.30). 
6.3.3.1.2 Chemical Contamination/Flooding 
6.3.3.1.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed cask (BSC 2005 [DIRS 171428], Section 
6.6.2), this potential event will not occur unless an event sequence leads to exposure of SNF to 
air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to air. The 
consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.3.1.3 Explosion/Implosion 
6.3.3.1.3.1 Hydrogen explosion involving batteries on a forklift. 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51). 
6.3.3.1.3.2 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 143 April 2005 
6.3.3.1.3.3 Hydrogen explosion involving batteries on a site prime mover 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51). 
6.3.3.1.4 Fire/Thermal 
6.3.3.1.4.1 Electrical fire associated with the entrance vestibule overhead crane 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.1.4.2 Electrical fire associated with handling equipment or other entrance 
vestibule electrical equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.1.4.3 Diesel fuel fire/explosion involving a diesel-powered SRTC tractor pulling or 
pushing an SRTC holding a loaded cask or MSC. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.1.4.4 Fire/explosion (battery/electrical fire) involving a site prime mover pulling or 
pushing an LWT or an OWT trailer holding a loaded cask. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.1.4.5 Fire/explosion (battery/electrical fire) associated with a forklift 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.1.4.6 Fire/explosion (battery/electrical fire) associated with a mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.1.4.7 Transient combustible fire in the entrance vestibule or the tools/parts storage 
room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 144 April 2005 
6.3.3.1.5 Radiation 
6.3.3.1.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.3.1.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.3.1.5.3 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.3.1.6 Fissile 
6.3.3.1.6.1 Criticality associated with an SRTC (holding a cask) derailment or collision 
followed by a load tipover or fall and rearrangement of the cask internals 
A criticality in the cask-receipt area of the CHF is not credible because design requirements and 
waste acceptance criteria will ensure criticality safety in transportation casks (Assumption 
5.1.1.4). 
6.3.3.1.6.2 Criticality associated with overturning or collision involving an LWT or an 
OWT trailer holding a cask and rearrangement of cask internals. 
A criticality in the cask-receipt area of the CHF is not credible because design requirements and 
waste acceptance criteria will ensure criticality safety in transportation casks (Assumption 
5.1.1.4). 
6.3.3.1.6.3 Criticality associated with an SRTC (holding a loaded MSC) derailment or 
collision followed by a load tipover or fall and rearrangement of the cask 
internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 145 April 2005 
6.3.3.2 Canister Transfer Cell (Canister Transfer) 
6.3.3.2.1 Collision/Crushing 
6.3.3.2.1.1 Slapdown of a cask onto an SRTC, a truck trailer, or the floor during 
upending of the cask to the vertical orientation 
This potential event is covered by Section 6.3.1.1. 
6.3.3.2.1.2 Drop of a cask from a canister transfer cell overhead crane onto the floor 
during the transfer from an SRTC or truck trailer to the cask preparation 
pit. 
This potential event is covered by Section 6.3.1.1. 
6.3.3.2.1.3 Drop or collision of a cask from a canister transfer cell overhead crane onto 
or against a sharp object during the transfer from an SRTC or truck trailer 
to the cask preparation pit 
Design and operational requirements will ensure that the load paths are kept free of objects that 
could puncture a transportation cask in case of a drop (Assumption 5.1.1.40). Crane-load 
collisions do not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.4 Drop of a loaded MSC from a canister transfer cell overhead crane onto the 
floor during the transfer from an SRTC to the cask preparation pit 
This potential event is covered by Section 6.3.1.1.2. 
6.3.3.2.1.5 Drop or collision of a loaded MSC from a canister transfer cell overhead 
crane onto or against a sharp object during the transfer from an SRTC to the 
cask preparation pit 
Design and operational requirements will ensure that the load paths are kept free of objects that 
could puncture an MSC in case of a drop (Assumption 5.1.1.40). Crane-load collisions do not 
initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.6 Drop or collision of a cask from a canister transfer cell overhead crane into 
or against the cask preparation pit or an MSC/WP loading pit during the 
transfer from an SRTC or truck trailer to the cask preparation pit 
Cask drops are covered in Section 6.3.1.1. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 146 April 2005 
6.3.3.2.1.7 Drop or collision of a loaded MSC from a canister transfer cell overhead 
crane into or against the cask preparation pit or an MSC/WP loading pit 
during the transfer from the SRTC to the cask preparation pit 
MSC drop is covered in Section 6.3.1.1.2. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.8 Slapdown of a cask or MSC in the pit area due to off-center cask or MSC 
lowering into the cask preparation pit and followed by a cask or MSC corner 
drop onto the edge of the pit and slapdown 
This potential event is covered by Sections 6.3.1.1 and 6.3.1.1.2. 
6.3.3.2.1.9 Drop or collision involving the pit moveable platform onto or against a cask 
or MSC in the cask preparation pit 
Operational requirements are assumed to ensure that the pit movable platform will not be 
operated in a manner that could breach a cask or MSC (Assumption 5.1.1.41). 
6.3.3.2.1.10 Handling equipment drop onto or against a cask or MSC 
Operational requirements are assumed to ensure that a drop of handling equipment onto a cask or 
MSC would not breach the cask or MSC (Assumption 5.1.1.30). 
6.3.3.2.1.11 Drop of a cask or MSC outer lid from a canister transfer cell overhead crane 
onto a cask or MSC inner lid, as applicable 
This potential event is bounded by the lid-drop event in Section 6.3.1.2. The expected number of 
occurrences is the lower because this event does not apply to WPs. The consequences are 
bounded because the inner lid is in place and will mitigate a release. 
6.3.3.2.1.12 Drop of a cask or MSC inner lid from a canister transfer cell overhead crane 
onto a canister inside the cask or MSC, as applicable 
Section 6.3.1.2 includes this potential event. 
6.3.3.2.1.13 Drop or collision of tools or handling equipment (including the outer lidlifting 
fixture, inner lid-lifting fixture, etc) onto or against a cask or MSC 
outer lid or a cask or MSC inner lid, as applicable 
An operational requirement is assumed to ensure that drops or collisions of miscellaneous tools 
and equipment onto or against the inner lid would not initiate an event sequence (Assumption 
5.1.1.32). If the outer lid is in place, it would provide additional protection against the initiation 
of an event sequence.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 147 April 2005 
6.3.3.2.1.14 Drop or collision of tools or handling equipment, including a lift fixture with 
pintle or a shield ring, onto or against a canister inside an open cask or MSC 
This potential event is included in Section 6.3.1.6. For DPC canisters, no credit is taken for the 
prevention or mitigation of a release that may be provided by the canister. 
6.3.3.2.1.15 Drop of a canister from a canister transfer cell overhead crane back into the 
cask or MSC being unloaded (including a naval SNF canister, a DOE SNF 
MCO, a DPC, a DOE HLW canister, or a [standardized] DOE SNF canister) 
This event is included in Section 6.3.1.5. 
6.3.3.2.1.16 Drop or collision of a DOE HLW canister or a [standardized] DOE SNF 
canister from a canister transfer cell overhead crane onto or against another 
[standardized] DOE SNF canister, or DOE HLW canister in the cask being 
unloaded, as applicable 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.17 Horizontal movement of a canister before it is fully vertically lifted out of a 
cask or MSC 
This collision event is included in Section 6.3.1.21. 
6.3.3.2.1.18 Drop of a canister from a canister transfer cell overhead crane onto the cell 
floor or other flat object during transfer from the cask or MSC to a WP or 
an MSC, as applicable, or during transfer to a canister staging pit 
This potential event is included in Section 6.3.1.5. 
6.3.3.2.1.19 Drop or collision of a canister from a canister transfer cell overhead crane 
onto or against a sharp object during transfer from the cask or MSC to a WP 
or an MSC, as applicable, or during transfer to a canister staging pit 
Design and operational requirements will ensure that the load paths are kept free of objects that 
could puncture a canister in case of a drop (Assumption 5.1.1.40). Crane-load collisions do not 
initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.20 Slapdown of a canister in an MSC/WP loading pit or the pit areas due to offcenter 
canister lowering into the WP or MSC, followed by a canister corner 
drop onto the edge of the pit and slapdown 
This potential event is included in Section 6.3.1.5.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 148 April 2005 
6.3.3.2.1.21 Drop or collision of a DPC, DOE HLW canister, or [standardized] DOE SNF 
canister from a canister transfer cell overhead crane into or against the 
empty MSC being loaded 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.22 Drop or collision of a naval SNF canister, a DOE HLW canister, a DOE SNF 
MCO, or a [standardized] DOE SNF canister from a canister transfer cell 
overhead crane into or against the WP being loaded. 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.23 Drop or collision of a DOE HLW canister from a canister transfer cell 
overhead crane onto or against another DOE HLW canister, a DOE SNF 
MCO, or a [standardized] DOE SNF canister in a WP 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.24 Drop or collision of a DOE HLW canister from a canister transfer cell 
overhead crane onto or against another DOE HLW canister or a 
[standardized] DOE SNF canister in an MSC. 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.25 Drop or collision of a [standardized] DOE SNF canister from a canister 
transfer cell overhead crane onto or against a DOE HLW canister in a WP or 
MSC 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.26 Drop or collision of a DOE SNF MCO from a canister transfer cell overhead 
crane onto or against another DOE SNF MCO or onto a DOE HLW canister 
in a WP 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 149 April 2005 
6.3.3.2.1.27 Drop or collision of a DOE SNF MCO from a canister transfer cell overhead 
crane onto or against a [standardized] DOE SNF canister or a drop of a 
[standardized] DOE SNF canister onto or against another [standardized] 
DOE SNF canister in a WP due to a misload 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.28 Drop or collision of a DOE SNF MCO from a canister transfer cell overhead 
crane onto or against a [standardized] DOE SNF canister or onto or against 
a DOE HLW canister or another misloaded DOE SNF MCO in an MSC due 
to a misload. 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.29 Drop or collision of a DOE HLW canister or a [standardized] DOE SNF 
canister from a canister transfer cell overhead crane into or against a 
canister staging pit 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.30 Slapdown of a DOE HLW canister or a [standardized] DOE SNF canister in 
the staging pit area due to off-center canister lowering into the pit and 
followed by a canister corner drop onto the edge of the staging pit and a 
slapdown 
This potential event is included in Section 6.3.1.5. 
6.3.3.2.1.31 Drop or collision of a DOE HLW canister, or a [standardized] DOE SNF 
canister from a canister transfer cell overhead crane onto or against the top 
of another DOE HLW canister, or [standardized] DOE SNF canister in a 
canister staging pit 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.2.1.32 Impact due to horizontal movement of a canister before it is fully vertically 
lifted out of a canister staging pit 
This collision event is included in Section 6.3.1.21. 
6.3.3.2.1.33 Drop of or collision of handling equipment onto or against a DOE HLW 
canister or a [standardized] DOE SNF canister in a canister staging pit 
This potential event is included in Section 6.3.1.6. For DPC canisters, no credit is taken for the 
prevention or mitigation of a release that may be provided by the canister.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 150 April 2005 
6.3.3.2.1.34 Drop of or collision of a canister staging pit shield plug onto or against a 
canister in the canister staging pit 
A design requirement will ensure that the shield plug will not fit into the opening far enough to 
breach a canister inside (Assumption 5.1.6.1). 
6.3.3.2.1.35 Drop or collision involving the pit moveable platform onto or against a 
loaded MSC in an MSC/WP loading pit 
Operational requirements are assumed to ensure that the portable platform will not be operated in 
a manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.3.2.1.36 Drop of a WP inner lid into an open, loaded WP 
The calculation in Section 6.3.1.2 includes this potential event. 
6.3.3.2.1.37 Drop of the MSC lid into an open, loaded MSC 
The calculation in Section 6.3.1.2 includes this potential event. 
6.3.3.2.1.38 Drop or collision of tools or handling equipment into or against an open, 
loaded or partially loaded, WP. 
This potential event is included in Section 6.3.1.6. 
6.3.3.2.1.39 Drop or collision of tools or handling equipment into or against an open, 
loaded or partially loaded MSC 
This potential event is included in Section 6.3.1.6. 
6.3.3.2.1.40 Drop or collision of tools or equipment (including a lid-lifting fixture) onto or 
against a loaded WP inner lid 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.2.1.41 Drop or collision of tools or equipment (including a lid-lifting fixture) onto or 
against the lid of a loaded, unsealed or sealed MSC 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.3.2.2 Chemical Contamination/Flooding 
6.3.3.2.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed canister (BSC 2005 [DIRS 171428], 
Section 6.6.2), this potential event will not occur unless an event sequence leads to exposure of
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 151 April 2005 
SNF to air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to 
air. The consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.3.2.3 Explosion/Implosion 
6.3.3.2.3.1 Cask sampling and purging system or decontamination (or other pneumatic 
or pressurized system) missile due to a fractured nozzle/valve 
stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.3.2.3.2 Explosion hazard associated with the cask sampling and purging system and 
the ignition of hydrogen that may have accumulated in the cask or MSC 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.3.2.3.3 Hydrogen explosion involving batteries on a forklift 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.3.2.3.4 Hydrogen explosion involving batteries on a site prime mover 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.3.2.4 Fire, Thermal 
6.3.3.2.4.1 Electrical fire associated with the canister transfer cell overhead cranes 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.2.4.2 Electrical fire associated with handling equipment or other canister transfer 
cell electrical equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.2.4.3 Diesel fuel fire/explosion on an SRTC tractor pushing an SRTC holding a 
loaded cask into the canister transfer cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 152 April 2005 
6.3.3.2.4.4 Fire/explosion (battery/electrical fire) involving a site prime mover pulling or 
pushing an LWT or an OWT trailer holding a loaded cask. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.2.4.5 Diesel fuel fire/explosion associated with the SRTC tractor pushing an SRTC 
holding an MSC 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.2.4.6 Fire/explosion (battery/electrical fire) associated with a forklift 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.2.4.7 HEPA filter fire due to excessive radioactive decay within the filter bed 
HEPA filters will be maintained well below their auto-ignition temperature to preclude a filter 
fire (Assumption 5.1.1.47). 
6.3.3.2.4.8 Canister overheating in the canister staging pit due to a loss of cooling 
resulting in excessive temperature and possible damage to canister contents 
and/or confinement 
This potential event is discussed in Section 6.3.1.26. 
6.3.3.2.4.9 Transient combustible fire in the canister transfer cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.2.4.10 Overheating of a loaded cask, WP, or MSC while staged in a pit due to a loss 
of cooling resulting in excessive temperature and possible damage to canister 
contents 
This potential event is discussed in Section 6.3.1.26. 
6.3.3.2.5 Radiation 
6.3.3.2.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. Consequence analysis will evaluate this hazard for 
event sequences and normal operations, as applicable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 153 April 2005 
6.3.3.2.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.3.2.5.3 Damage or rupture of cask sampling and purging system, leading to a release 
of cask internal gases and radioactive material 
The sampling operation will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses (BSC 2004 
[DIRS 172098], Section 3.2.2.1.1). Although a rupture leading to a radiological release would 
be an abnormal occurrence, radiation protection programs will ensure that such an occurrence 
would not contribute significantly to the normal operations dose. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.3.2.5.4 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Exposure of workers to radiation due to this potential event will be managed as a normaloperations 
dose by procedures for monitoring radiation doses and assigning work, which ensure 
that workers do not receive excessive radiation doses. See Section 7.4 for a list of potential 
events and conditions that are treated as normal operations. 
6.3.3.2.5.5 Inadvertent opening of a canister transfer cell shield door or a cask 
preparation pit cover or an MSC/WP pit cover, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers (but not the public) to radiation will be 
limited by design features and operating procedures that ensure that such events are not 
Category 1 (Assumption 5.1.1.57). 
6.3.3.2.5.6 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.3.2.6 Fissile 
6.3.3.2.6.1 Criticality associated with a drop or slapdown of a loaded cask from a 
canister transfer cell overhead crane and a rearrangement of cask internals 
A criticality is not credible because design requirements and waste acceptance criteria will 
ensure criticality safety in transportation casks (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 154 April 2005 
6.3.3.2.6.2 Criticality associated with a drop or slapdown of a loaded MSC from a 
canister transfer cell overhead crane and a rearrangement of cask internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.3.2.6.3 Criticality associated with a drop or slapdown of a loaded WP (unsealed) 
from a canister transfer cell overhead crane and a rearrangement of WP 
internals 
Because the WP does not spill its contents (Assumption 5.1.3.11) and moderator intrusion into 
the WP is controlled, the unsealed WP will remain subcritical (Assumptions 5.1.3.2 and 
5.1.1.21). 
6.3.3.2.6.4 Criticality associated with a drop or slapdown of a [standardized] DOE SNF 
canister, a naval SNF canister, a DOE SNF MCO, a DPC, or a DOE HLW 
canister and a rearrangement of canister internals 
Design calculations will show that dropping a DOE SNF canister within its design basis will not 
lead to a criticality if moderator control is in effect (Assumption 5.1.1.3). A requirement will 
ensure that DPCs are designed such that drops, collisions, and other handling impacts (allowing 
for rearrangement of container internals and optimal moderator intrusion) cannot lead to a 
nuclear criticality (Assumption 5.1.1.4). The potential for criticality for naval canisters is 
addressed in Attachment I, where it is demonstrated that a criticality associated with the drop of 
a naval canister is Beyond Category 2. There is no potential for criticality of HLW canisters 
(Assumption 5.2.1.19). 
6.3.3.2.6.5 Criticality associated with a misload of a WP or an MSC 
A criticality due to misload of an MSC is not credible because a design requirement will ensure 
that MSCs remain subcritical even with the most reactive credible configuration of the fissile 
material and optimal moderation (Assumption 5.1.1.4). A criticality due to a canister misload of 
a WP is not credible because a design requirement will ensure that WPs and MSCs are designed 
such that they can be loaded with canisters that are acceptable for disposal without leading to a 
preclosure nuclear criticality provided that moderator control is in effect (Assumptions 5.1.3.2 
and 5.1.1.21). 
6.3.3.2.6.6 Criticality associated with a misload of a canister staging pit 
A design requirement will ensure that misloading standardized DOE SNF canisters in the CHF 
staging pits cannot lead to a nuclear criticality (Assumption 5.1.1.2). Neither MCOs nor naval 
canisters will be staged (Assumption 5.2.1.20) There is no potential for criticality of HLW 
canisters (Assumption 5.2.1.19).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 155 April 2005 
6.3.3.2.6.7 Criticality associated with a drop of heavy equipment onto an unsealed, 
loaded cask, WP, or MSC and a rearrangement of the container internals 
For the WP, provided that moderators are controlled, the unsealed WP will remain subcritical 
(Assumptions 5.1.3.2 and 5.1.1.21). Design requirements and waste acceptance criteria will 
ensure criticality safety in transportation casks and MSCs (Assumption 5.1.1.4). 
6.3.3.3 Canister Transfer Cell (WP Transfer to WP Closure, MSC Closure and 
Removal) 
6.3.3.3.1 Collision/Crushing 
6.3.3.3.1.1 Drop or collision of handling equipment or a lifting fixture onto or against a 
loaded WP inner lid 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.3.1.2 Drop or collision of handling equipment or a lifting fixture onto or against a 
loaded MSC lid 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.3.3.1.3 Impact due to horizontal movement of a loaded WP by a canister transfer 
cell overhead crane before it is fully lifted vertically out of the MSC/WP 
loading pit. 
This collision event is included in Section 6.3.1.21. 
6.3.3.3.1.4 Drop or collision of an unsealed, loaded WP from a canister transfer cell 
overhead crane back into or against the MSC/WP loading pit 
This potential event is included in the calculation presented in Section 6.3.1.7. 
6.3.3.3.1.5 Drop of an unsealed, loaded WP from a canister transfer cell overhead crane 
onto the cell floor or a pit cover during the lift and transfer to the WP 
positioning cell pedestal and trolley 
This potential event is included in the calculation presented in Section 6.3.1.7. A design 
requirement will ensure that the WP will not penetrate the pit cover (Assumption 5.1.6.6).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 156 April 2005 
6.3.3.3.1.6 Drop or collision of an unsealed, loaded WP from a canister transfer cell 
overhead crane onto or against a sharp object during the lift and transfer to 
the WP positioning cell pedestal and trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.3.3.1.7 Slapdown of a loaded, unsealed WP onto the cell floor, into a wall, or onto a 
pit cover following a drop from a canister transfer cell overhead crane onto 
the edge of the trolley, a pit edge, or pit cover during the lift and transfer to 
the WP positioning cell pedestal and trolley 
This potential event is included in the calculation presented in Section 6.3.1.7. A design 
requirement will ensure that the WP will not penetrate the pit cover (Assumption 5.1.6.6). 
6.3.3.3.1.8 Drop or collision of an unsealed, loaded WP from a canister transfer cell 
overhead crane onto or against a loaded or partially loaded MSC or WP 
(with no lid in place) in an MSC/WP loading pit (with no pit cover in place) 
during the lift and transfer to the WP positioning cell pedestal and trolley 
This potential event sequence will be precluded by operational and design requirements. 
Operational requirements will ensure that a loaded WP is not carried over or near a loaded 
MSC/WP loading pit (Assumption 5.1.6.2) and that pit covers are replaced whenever individual 
waste-form handling operations are suspended unless the loading operation is complete and the 
next operation involving the overhead crane is to remove the associated WP or MSC from the pit 
(Assumption 5.1.6.3). 
6.3.3.3.1.9 Drop or collision of a unsealed, loaded WP from a canister transfer cell 
overhead crane onto or against a loaded MSC or WP (with lid in place) in an 
MSC/WP loading pit (with no pit cover in place) during the lift and transfer 
to the WP positioning cell pedestal and trolley 
This potential event is rendered Beyond Category 2 by the same operational requirements 
invoked in Section 6.3.3.3.1.8. 
6.3.3.3.1.10 Drop or collision of an unsealed, loaded WP from a canister transfer cell 
overhead crane onto or against, a loaded, unsealed WP on the opposite WP 
positioning cell pedestal and trolley during the lift and transfer to a WP 
positioning cell pedestal and trolley 
An operational requirement will ensure that, whenever a waste-package trolley is being loaded, 
the opposite trolley is located in its positioning cell or is otherwise out of the way (Assumption 
5.1.6.4). Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 157 April 2005 
6.3.3.3.1.11 Drop or collision of an unsealed, loaded WP from a canister transfer cell 
overhead crane onto or against, a loaded, sealed WP on the opposite WP 
positioning cell pedestal and trolley during the lift and transfer to a WP 
positioning cell pedestal and trolley 
The operational requirements cited in Section 6.3.3.3.1.10 preclude this potential event. 
6.3.3.3.1.12 Slapdown of a loaded, unsealed WP onto the floor and then across or into an 
empty MSC/WP loading pit (with no pit cover in place) following a drop 
from a canister transfer cell overhead crane onto the edge of the trolley or pit 
edge during the lift and transfer to the WP positioning cell pedestal and 
trolley 
The calculation presented in Section 6.3.1.7 includes this potential event. 
6.3.3.3.1.13 Slapdown of a loaded, unsealed WP onto the floor and then across or into an 
MSC/WP loading pit (with no pit cover in place and a loaded or partially 
loaded, sealed or unsealed MSC or WP in place) following a drop from a 
canister transfer cell overhead crane onto the edge of the trolley or pit edge 
during the lift and transfer to the WP positioning cell pedestal and trolley 
The calculation presented in Section 6.3.1.7 includes this potential event. The operational 
requirements cited in Section 6.3.3.3.1.8 preclude a drop into an occupied loading pit. 
6.3.3.3.1.14 Slapdown of a loaded, unsealed WP that subsequently impacts a loaded, 
unsealed WP on the opposite WP positioning cell trolley following a drop 
from a canister transfer cell overhead crane onto the edge of the opposite WP 
positioning cell trolley, a pit edge, or other object during the lift and transfer 
to the WP positioning cell pedestal and trolley 
The operational requirements cited in Section 6.3.3.3.1.10 preclude this potential event. 
6.3.3.3.1.15 Slapdown of a loaded, unsealed WP that subsequently impacts a loaded, 
sealed WP on the opposite WP positioning cell trolley following a drop from 
a canister transfer cell overhead crane onto the edge of the WP positioning 
cell trolley, a pit edge, or other object during the lift and transfer to the WP 
positioning cell pedestal and trolley 
The operational requirements cited in Section 6.3.3.3.1.10 preclude this potential event. 
6.3.3.3.1.16 Impact due to horizontal movement of a loaded, sealed MSC by a canister 
transfer cell overhead crane before it is fully vertically lifted out of the 
MSC/WP loading pit 
This collision event is included in Section 6.3.1.21.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 158 April 2005 
6.3.3.3.1.17 Drop or collision of a loaded, sealed MSC from a canister transfer cell 
overhead crane back into or against the MSC/WP loading pit during MSC 
removal and transfer to the SRTC 
MSC drop is covered in Section 6.3.1.1.2. Note that the transfers are different, but there are still 
two transfers: (1) from the loading pit to the SRTC before aging and (2) after aging, from the 
SRTC to the trolley in the DTF. Crane-load collisions do not initiate Category 1 or Category 2 
event sequences (Section 6.3.1.21). 
6.3.3.3.1.18 Slapdown of a loaded, sealed MSC onto the cell floor, into a wall, or onto a 
pit cover following a drop from a canister transfer cell overhead crane onto 
the edge of the MSC/WP loading pit or the SRTC during MSC removal from 
the pit and transfer to the SRTC 
This potential event is covered by Section 6.3.1.1.2. Note that the transfers are different, but 
there are still two transfers: (1) from the loading pit to the SRTC before aging and (2) after 
aging, from the SRTC to the trolley in the DTF. A design requirement will ensure that a dropped 
MSC will not penetrate the pit cover (Assumption 5.1.6.6). 
6.3.3.3.1.19 Drop or collision of a loaded, sealed MSC from a canister transfer cell 
overhead crane onto or against the SRTC following removal of the MSC 
from the MSC/WP loading pit during transfer to the SRTC for removal from 
the building. 
MSC drop is covered in Section 6.3.1.1.2. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.3.3.1.20 Drop of a loaded, sealed MSC from a canister transfer cell overhead crane 
onto the canister transfer cell floor or a pit cover following removal of the 
MSC from the MSC/WP loading pit 
MSC drop is covered in Section 6.3.1.1.2. A design requirement will ensure that a dropped MSC 
will not penetrate the pit cover (Assumption 5.1.6.6). 
6.3.3.3.1.21 Drop or collision of a loaded, sealed MSC from a canister transfer cell 
overhead crane onto or against a sharp object following removal of the MSC 
from the MSC/WP loading pit 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 159 April 2005 
6.3.3.3.1.22 Collision of the SRTC (holding a loaded, sealed MSC) with the entrance 
vestibule doors, the tool/parts storage room doors, or the canister transfer 
cell shield doors 
A design or operational requirement is assumed to ensure that a collision between the entrance 
vestibule doors, the tool/parts storage room doors, or the canister transfer cell shield doors and 
the SRTC will not overturn the SRTC or cause it to drop its load (Assumption 5.1.1.38). 
6.3.3.3.1.23 The entrance vestibule doors, the tool/parts storage room doors, or the 
canister transfer cell shield doors close on the SRTC (holding a loaded, 
sealed MSC) 
A design requirement is assumed to ensure that closure of the various doors onto the SRTC will 
not overturn the SRTC or cause it to drop its load (Assumption 5.1.1.13). Because the SRTC 
remains upright there is no threat to the integrity of the MSC. 
6.3.3.3.2 Chemical Contamination/Flooding 
6.3.3.3.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed canister (BSC 2005 [DIRS 171428], 
Section 6.6.2), this potential event will not occur unless an event sequence leads to exposure of 
SNF to air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to 
air. The consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.3.3.3 Explosion/Implosion 
6.3.3.3.3.1 MSC inerting system (or other pneumatic or pressurized system) missile due 
to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.3.3.4 Fire, Thermal 
6.3.3.3.4.1 Electrical fire associated with the canister transfer cell overhead cranes 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.3.4.2 Electrical fire associated with handling equipment or other canister transfer 
cell electrical equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 160 April 2005 
6.3.3.3.4.3 Diesel fuel fire/explosion associated with the SRTC tractor pulling an SRTC 
holding an MSC 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.3.4.4 HEPA filter fire due to excessive radioactive decay within the filter bed 
HEPA filters will be maintained well below their auto-ignition temperature to preclude a filter 
fire (Assumption 5.1.1.47). 
6.3.3.3.4.5 Transient combustible fire in the canister transfer cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.3.4.6 Thermal hazard (from decay heat) associated with a vertical orientation of a 
non-inerted, loaded, unsealed WP with normal cooling 
This potential event is covered in Section 6.3.3.3.2.1. 
6.3.3.3.4.7 Overheating of a loaded, unsealed (and uninerted) WP or MSC due to a loss 
of cooling resulting in excessive temperature and possible damage to canister 
contents 
This potential event is discussed in Section 6.3.1.26. 
6.3.3.3.5 Radiation 
6.3.3.3.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.3.3.5.2 Loss of confinement zones due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.3.3.5.3 Inadvertent opening of a canister transfer cell shield door or a WP 
positioning cell shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 161 April 2005 
6.3.3.3.5.4 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.3.3.6 Fissile 
6.3.3.3.6.1 Criticality associated with a drop or slapdown of a loaded MSC from a 
canister transfer cell overhead crane and a rearrangement of cask internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.3.3.6.2 Criticality associated with an SRTC (holding a loaded MSC) derailment or 
collision followed by a load tipover or fall and rearrangement of the cask 
internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.3.3.6.3 Criticality associated with a drop or slapdown of a loaded, unsealed WP 
from a canister transfer cell overhead crane and a rearrangement of WP 
internals 
Because the WP does not spill its contents (Assumption 5.1.3.11) and moderator intrusion into 
the WP is controlled, the unsealed WP will remain subcritical (Assumptions 5.1.3.2 and 
5.1.1.21). 
6.3.3.3.6.4 Criticality associated with a drop of heavy equipment onto an unsealed, 
loaded WP or MSC and a rearrangement of the container internals 
For the WP, provided that moderators are controlled, the unsealed WP will remain subcritical 
(Assumptions 5.1.3.2 and 5.1.1.21). A criticality in an MSC is not credible because a design 
requirement will ensure that MSCs remain subcritical even with the most reactive credible 
configuration of the fissile material and optimal moderation (Assumption 5.1.1.4). 
6.3.3.4 WP Closure 
6.3.3.4.1 Collision/Crushing 
6.3.3.4.1.1 Derailment of a trolley holding a loaded, unsealed WP followed by a load 
tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright there is no 
event sequence.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 162 April 2005 
6.3.3.4.1.2 Drop or collision of equipment from a canister transfer cell overhead crane 
onto or against a loaded, unsealed WP positioned on a pedestal on a trolley 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.4.1.3 Collision involving the trolley holding the loaded, unsealed WP and the 
shield doors between the canister transfer cell and the WP positioning cell 
This potential event is included in Section 6.3.1.22. 
6.3.3.4.1.4 Shield doors between the canister transfer cell and the WP positioning cell 
close on the trolley holding the loaded, unsealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). 
6.3.3.4.1.5 Lid drop onto a WP from the lid placement fixture equipment during the 
welding process 
The event is included with the generalized lid-drop event sequence discussed in Section 6.3.1.2. 
6.3.3.4.1.6 Equipment drop onto a WP during the welding process 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.4.1.7 Drop or collision of equipment from a canister transfer cell overhead crane 
onto or against a loaded, sealed WP positioned on a pedestal on a trolley 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.4.1.8 Collision involving the trolley holding the loaded, sealed WP and the shield 
doors between the WP positioning cell and the canister transfer cell 
This potential event is included in Section 6.3.1.22. 
6.3.3.4.1.9 Shield doors between the WP positioning cell and the canister transfer cell 
close on the trolley holding the loaded, sealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright, the WP will not breach.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 163 April 2005 
6.3.3.4.2 Chemical Contamination/Flooding 
6.3.3.4.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the CHF does not handle uncanistered waste, the SNF is contained in a sealed canister 
(BSC 2005 [DIRS 171428], Section 6.6.2). This potential event cannot occur unless an event 
sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible outcome of 
an event that exposes SNF to air. The consequence analyses will account for the possibility of 
oxidation, where applicable. 
6.3.3.4.3 Explosion/Implosion 
6.3.3.4.3.1 WP inerting system (or other pneumatic or pressurized system) missile due 
to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.3.4.3.2 Explosion hazard associated with the WP purging and inerting system and 
the ignition of hydrogen that may have accumulated in the WP 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.3.4.4 Fire, Thermal 
6.3.3.4.4.1 Electrical fire associated with handling equipment and other electricallypowered 
equipment in the WP closure cell or the WP positioning cell, 
including the overhead cranes and the welding subsystem in the WP closure 
cells 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.4.4.2 Electrical fire associated with a motor on a WP trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.4.4.3 Canister/SNF damage by burn-through during welding process/heat damage 
Burn-through of the inner lid is not possible with the gas tungsten arc welding process, which is 
used for the closure welds (BSC 2005 [DIRS 171428], Section 6.6.3.10; BSC 2004 [DIRS 
172428], Section 3).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 164 April 2005 
6.3.3.4.4.4 Thermal hazard/canister/SNF overheating in a WP during the welding 
process resulting in excessive cladding temperature and possible zircaloy 
cladding (or other cladding) unzipping 
Overheating of the WP contents due to welding is not possible using the gas tungsten arc 
welding process, which is used for the closure welds (BSC 2005 [DIRS 171428], Section 
6.6.3.10; BSC 2004 [DIRS 172428], Section 3). 
6.3.3.4.4.5 Overheating of a loaded WP due to a loss of cooling resulting in excessive 
temperature and possible damage to the canister contents 
This potential event is discussed in Section 6.3.1.26. 
6.3.3.4.4.6 Transient combustible fire in the WP closure cell or the WP positioning cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.4.5 Radiation 
6.3.3.4.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.3.4.5.2 Glovebox leak leads to a radiological release 
Gloveboxes will be inspected for proper functioning and monitored for release of radioactive 
contamination. Therefore, exposure of workers to radiation due to a glovebox leak will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. See Section 
7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.3.4.5.3 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.3.4.5.4 Inadvertent opening of a canister transfer cell shield door or a WP 
positioning cell shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 165 April 2005 
6.3.3.4.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.3.4.6 Fissile 
6.3.3.4.6.1 Criticality associated with a trolley holding a sealed or unsealed WP 
derailment followed by a load tipover or fall and rearrangement of the 
container internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright, there is no 
mechanism for reconfiguration of internals and, therefore, no criticality. 
6.3.3.4.6.2 Criticality associated with a drop of heavy equipment onto an unsealed, 
loaded WP and a rearrangement of the container internals 
A design requirement will ensure criticality safety for unsealed WPs with moderator control in 
effect (Assumptions 5.1.3.2 and 5.1.1.21). 
6.3.3.5 WP Loadout: Canister Transfer Cell, WP Tool Storage Room, Exit Vestibule 
6.3.3.5.1 Collision/Crushing 
6.3.3.5.1.1 Derailment of a trolley holding a loaded, sealed WP followed by a load 
tipover or fall. 
A design requirement is assumed to ensure that a derailment of a trolley will not cause the trolley 
to overturn and allow the WP to fall to the floor (Assumption 5.1.1.36). Because the trolley 
remains upright there is no threat to the integrity of the WP. 
6.3.3.5.1.2 Drop of a loaded, sealed WP from a canister transfer cell overhead crane 
onto the floor during transfer from the trolley to the survey area 
Section 6.3.1.8 includes this potential event. 
6.3.3.5.1.3 Drop or collision of a loaded, sealed WP from a canister transfer cell 
overhead crane onto or against a sharp object during transfer from the 
trolley to the survey area 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 166 April 2005 
6.3.3.5.1.4 Slapdown of a loaded, sealed WP that subsequently impacts a loaded, 
unsealed WP on the opposite WP positioning cell trolley following a drop 
from a canister transfer cell overhead crane onto the edge of the opposite WP 
positioning cell trolley, a pit edge, or other object during the lift and transfer 
to the survey area 
The operational requirements cited in Section 6.3.3.3.1.10 preclude this potential event. 
6.3.3.5.1.5 Slapdown of a loaded, sealed WP that subsequently impacts a loaded, sealed 
WP on the opposite WP positioning cell trolley following a drop from a 
canister transfer cell overhead crane onto the edge of the WP positioning cell 
trolley, a pit edge, or other object during the lift and transfer to the survey 
area 
The operational requirements cited in Section 6.3.3.3.1.10 preclude this potential event. 
6.3.3.5.1.6 Drop or collision of a sealed, loaded WP from a canister transfer cell 
overhead crane onto or against a loaded, unsealed WP on the opposite WP 
positioning cell pedestal and trolley during the lift and transfer to the survey 
area 
The operational requirements cited in Section 6.3.3.3.1.10 preclude the potential drop event. The 
potential collision event is included in Section 6.3.1.21. 
6.3.3.5.1.7 Drop or collision of a sealed, loaded WP from a canister transfer cell 
overhead crane onto or against, a loaded, sealed WP on the opposite WP 
positioning cell pedestal and trolley during the lift and transfer to the survey 
area 
The operational requirements cited in Section 6.3.3.3.1.10 preclude this potential event. The 
potential collision event is included in Section 6.3.1.21. 
6.3.3.5.1.8 Drop of a loaded, sealed WP from a canister transfer cell overhead crane 
onto the floor during transfer from the survey area to the tilting machine 
This potential event is included in Section 6.3.1.8. 
6.3.3.5.1.9 Drop of a loaded, sealed WP from a canister transfer cell overhead crane 
back onto the pedestal on the trolley during the transfer from the survey 
area to the tilting machine. 
Section 6.3.1.8 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 167 April 2005 
6.3.3.5.1.10 Drop or collision of a loaded, sealed WP from a canister transfer cell 
overhead crane onto or against a sharp object (including the tilting machine) 
during transfer from the survey area to the tilting machine 
Section 6.3.1.8 includes the potential drop event. The potential collision event is included in 
Section 6.3.1.21. 
6.3.3.5.1.11 Slapdown (either forward into the WP turntable or backward onto the floor) 
of a loaded, sealed WP in the tilting machine from a canister transfer cell 
overhead crane during the lowering of the WP to the horizontal position on 
the pallet previously placed on the WP turntable 
The WP is assumed to survive a forward slapdown without breach (Assumption 5.1.3.12). A 
design requirement is assumed to prevent backward slapdowns (Assumption 5.1.1.53). 
6.3.3.5.1.12 Collision of the tilting machine against a loaded, sealed WP on a pallet on the 
WP turntable. 
A design or operational requirement is assumed to ensure that a collision between the tilting 
machine and a WP would not initiate an event sequence (Assumption 5.1.3.10). 
6.3.3.5.1.13 Drop or collision of a lifting collar from a canister transfer cell overhead 
crane onto or against a WP after removal of the collar from the WP collar 
removal machine. 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.5.1.14 Collision or impact of the trunnion collar removal machine and a loaded, 
sealed WP positioned on a pallet positioned on the WP turntable 
A design or operational requirement is assumed to ensure that a collision between the trunnion 
collar removal machine and a WP would not breach the WP (Assumption 5.1.3.10). 
6.3.3.5.1.15 Drop of a loaded, sealed WP positioned on a pallet (from a horizontal 
position) from a canister transfer cell overhead crane onto the floor or the 
bedplate during transfer of the WP and pallet from the WP turntable to the 
WP transporter bedplate 
Section 6.3.1.8 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 168 April 2005 
6.3.3.5.1.16 Drop or collision of a loaded, sealed WP positioned on a pallet (from a 
horizontal position) from a canister transfer cell overhead crane onto or 
against a sharp object during transfer of the WP and pallet from the WP 
turntable to the WP transporter bedplate 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.3.5.1.17 Equipment drop or collision (including lifting yokes) onto or against a 
loaded, sealed WP when the WP is on the pallet on the WP turntable or when 
the WP is on the pallet on the WP transporter bedplate 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.3.5.1.18 Collision involving a WP transporter (holding the sealed WP on a pallet) and 
the shield doors between the canister transfer cell and the WP tool storage 
room 
A design requirement is assumed to ensure that a collision of the WP transporter would not cause 
a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). 
6.3.3.5.1.19 The shield doors between the canister transfer cell and the WP tool storage 
room close on the WP transporter (holding the sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a transporter 
would not overturn the transporter or cause it to drop its load (Assumption 5.1.1.13). Because 
the transporter remains upright there is no threat to the integrity of the WP. 
6.3.3.5.1.20 Collision involving WP transporter (holding the sealed WP on a pallet) and 
the shield doors between the WP tool storage room and the exit vestibule 
A design requirement is assumed to ensure that a collision of the WP transporter would not cause 
a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). 
6.3.3.5.1.21 The doors between the WP tool storage room and the exit vestibule close on 
the WP transporter (holding the sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright the WP will not breach. 
6.3.3.5.1.22 Collision involving WP transporter (holding the sealed WP on a pallet) and 
the doors between the exit vestibule and the ambient air (outside) 
A design requirement is assumed to ensure that a collision of the WP transporter would not cause 
a WP breach (Assumptions 5.1.7.3 and 5.1.7.7).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 169 April 2005 
6.3.3.5.1.23 Doors between the exit vestibule and the ambient air (outside) close on the 
WP transporter (holding the sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a WP transporter 
would not overturn the WP transporter or cause it to drop its load (Assumption 5.1.1.13). 
6.3.3.5.1.24 Derailment of a WP transporter in the exit vestibule, WP tool storage room, 
or WP loadout area of the canister transfer cell followed by a load tipover or 
fall 
A design requirement is assumed to ensure that a derailment of the WP transporter would not 
cause a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). 
6.3.3.5.2 Chemical Contamination/Flooding 
6.3.3.5.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed canister and WP, this potential event will 
not occur unless an event sequence leads to exposure of SNF to air (BSC 2005 [DIRS 171428], 
Section 6.6.2). Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF 
to air. The consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.3.5.3 Explosion/Implosion 
6.3.3.5.3.1 Hydraulic system or other pneumatic or pressurized system missile due to a 
fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.3.5.4 Fire, Thermal 
6.3.3.5.4.1 Electrical fire associated with the WP transporter loadout area housing the 
equipment for WP tilt and WP transporter loading, as well as the WP tool 
storage room and the exit vestibule (including the WP trunnion collar 
removal machine, the tilting machine, and the WP turntable) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.5.4.2 Electrical fire associated with the overhead bridge cranes 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 170 April 2005 
6.3.3.5.4.3 Electrical fire associated with equipment on the WP transporter, including 
motors to extend the WP transporter bedplate 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.5.4.4 Electrical fire associated with the WP transporter locomotive 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.5.4.5 Electrical fire associated with a motor on a WP trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.5.4.6 Overheating of a loaded, sealed WP due to a loss of cooling resulting in 
excessive temperature and possible damage to the canister contents 
This potential event is discussed in Section 6.3.1.26. 
6.3.3.5.4.7 Transient combustible fire in the canister transfer area, the WP tool storage 
room, or the exit vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.3.5.5 Radiation 
6.3.3.5.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.3.5.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.3.5.5.3 Inadvertent opening of a canister transfer cell shield door, leading to a 
worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 171 April 2005 
6.3.3.5.5.4 Inadvertent opening of the WP transporter shielded enclosure doors, leading 
to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.3.5.6 Fissile 
6.3.3.5.6.1 Criticality associated with a trolley holding a WP derailment followed by a 
load tipover or fall and rearrangement of the WP internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright, there is no 
mechanism for reconfiguration of internals and, therefore, no criticality. 
6.3.3.5.6.2 Criticality associated with a WP transporter derailment followed by a load 
tipover or fall and rearrangement of the WP internals 
A design requirement is assumed to ensure that a derailment of the WP transporter would not 
cause a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). Another design requirement is assumed 
to preclude criticality in sealed WPs (Assumption 5.1.3.1). 
6.3.3.5.6.3 Criticality associated with a drop, slapdown, or collision of a WP and a 
rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). 
6.3.3.6 CHF (Empty Transportation Cask and MSC Removal): Canister Transfer 
Cell, WP Tool Storage Room, Exit Vestibule 
No events identified.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 172 April 2005 
6.3.4 DTF 
A description of the operations in this facility and a listing of the hazards and potential events is 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.3). 
6.3.4.1 Cask and MSC Entrance Vestibule, Cask and MSC SRTC Receipt Area, Cask 
and MSC to Trolley Transfer Room 
6.3.4.1.1 Collision/Crushing 
6.3.4.1.1.1 SRTC derailment involving a loaded cask (with impact limiters installed) 
followed by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment would not breach a 
transportation cask. 
6.3.4.1.1.2 Collision of an SRTC carrying a loaded cask (with impact limiters installed) 
with the cask and MSC entrance vestibule doors or the cask and MSC SRTC 
receipt area doors 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a collision within the facility would 
not breach a transportation cask. 
6.3.4.1.1.3 The cask and MSC entrance vestibule doors or the cask and MSC SRTC 
receipt area doors close on an SRTC carrying a loaded cask (with impact 
limiters installed) 
A design requirement is assumed to ensure that closure of the entrance vestibule doors or shield 
doors onto an SRTC would not overturn the SRTC or cause it to drop its load (Assumption 
5.1.1.13). Because the SRTC remains upright there is no threat to the integrity of the cask. 
6.3.4.1.1.4 MSC transporter collision or overturning involving a loaded MSC followed 
by a load tipover or fall 
Design and operational requirement are assumed to ensure that an MSC transporter will not 
collide or overturn (Assumption 5.1.1.38). Because the transporter remains upright there is no 
threat to the integrity of the cask.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 173 April 2005 
6.3.4.1.1.5 Collision of an MSC transporter carrying a loaded MSC with the cask and 
MSC entrance vestibule doors or the cask and MSC SRTC receipt area 
shield doors 
Design and operational requirements are assumed to ensure that a collision involving the MSC 
transporter with the MSC entrance vestibule doors or the cask and MSC SRTC receipt area 
shield doors would not overturn it or cause it to drop its load (Assumption 5.1.1.38). Because 
the MSC does not fall off the transporter as a result of the collision, there is no threat to its 
integrity. 
6.3.4.1.1.6 The cask and MSC entrance vestibule doors or the cask and MSC SRTC 
receipt area shield doors close on an MSC transporter carrying a loaded 
MSC 
A design requirement is assumed to ensure that closure of the shield doors onto an MSC 
transporter would not overturn it or cause it to drop its load (Assumption 5.1.1.13). Because the 
MSC does not fall off the transporter as a result of the collision, there is no threat to its integrity. 
6.3.4.1.1.7 Collision of a mobile elevated platform with a loaded cask during removal of 
the personnel barriers and impact limiters or during survey activities 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach or overturn a transportation cask (Assumption 5.1.1.41). 
6.3.4.1.1.8 Forklift collision with a cask on an SRTC (with or without impact limiters 
installed on the cask) or the SRTC holding the cask 
Operational requirements are assumed to ensure that forklifts will not be operated in a manner 
that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.4.1.1.9 Collision between a forklift and an MSC positioned on the floor, an MSC on 
a pedestal on a trolley, or the MSC transporter holding the MSC 
Operational requirements are assumed to ensure that forklifts will not be operated in a manner 
that could breach an MSC (Assumption 5.1.1.41). 
6.3.4.1.1.10 Collision between a mobile elevated platform and an MSC positioned on the 
floor, an MSC on a pedestal on a trolley, or the MSC transporter holding the 
MSC 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.4.1.1.11 Drop or collision of personnel barriers or impact limiters from the receipt 
area crane onto or against a loaded cask 
Operational requirements will ensure that equipment associated with cask preparation and 
handling will not breach the cask (Assumption 5.1.1.30).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 174 April 2005 
6.3.4.1.1.12 Slapdown of a loaded cask onto an SRTC during the upending of the loaded 
cask to the vertical orientation by the overhead crane 
This potential event is covered by Section 6.3.1.1. 
6.3.4.1.1.13 Drop of a loaded cask from an overhead crane onto the floor during the 
transfer from an SRTC to a pedestal previously staged on a trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.4.1.1.14 Drop of a loaded cask from an overhead crane onto the pedestal on a trolley 
during the transfer from an SRTC to a pedestal previously staged on a 
trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.4.1.1.15 Drop or collision of a loaded cask from an overhead crane onto or against a 
sharp object during the transfer from an SRTC to a pedestal previously 
positioned on a trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.1.1.16 Slapdown of a loaded cask following a drop from an overhead crane onto the 
edge of the trolley or pedestal during transfer of the cask from the SRTC to 
the pedestal on a trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.4.1.1.17 Collision of a loaded cask suspended from an overhead crane with the shield 
doors separating the cask and MSC SRTC receipt area and the cask and 
MSC to trolley transfer room during the transfer of the cask from the SRTC 
to the trolley 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.1.1.18 Closing of the shield doors separating the cask and MSC SRTC receipt area 
and the cask and MSC to trolley transfer room (striking a loaded cask while 
it is suspended from the overhead crane) during the transfer of the cask from 
the SRTC to the pedestal on a trolley 
A design requirement is assumed to ensure that closure of the shield doors onto a cask suspended 
from the overhead crane will not breach the cask or cause the crane to drop the load (Assumption 
5.1.1.13).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 175 April 2005 
6.3.4.1.1.19 Drop of a loaded MSC from an overhead crane onto the floor during the 
transfer from an SRTC to a pedestal previously positioned on a trolley 
This potential event is covered by Section 6.3.1.1.2. 
6.3.4.1.1.20 Drop of a loaded MSC from an overhead crane onto the pedestal on a trolley 
during the transfer from an SRTC to a pedestal previously positioned on a 
trolley. 
This potential event is covered by Section 6.3.1.1.2. 
6.3.4.1.1.21 Drop or collision of a loaded MSC from an overhead crane onto or against a 
sharp object during the transfer from the floor (after delivery by the MSC 
transporter) to a pedestal previously staged on a trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.1.1.22 Collision of a loaded MSC suspended from an overhead crane with the shield 
doors separating the cask and MSC SRTC receipt area and the cask and 
MSC to trolley transfer room during transfer of the MSC from the floor 
(after delivery by the MSC transporter) to the pedestal on a trolley 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.1.1.23 Closing of the shield doors separating the cask and MSC SRTC receipt area 
and the cask and MSC to trolley transfer room (striking a loaded MSC while 
it is suspended from the overhead crane) during the transfer of the MSC 
from the floor (after delivery by the MSC transporter) to the pedestal on a 
trolley 
A design requirement is assumed to ensure that closure of the shield doors onto a cask suspended 
from the overhead crane will not breach the cask or cause the crane to drop the load (Assumption 
5.1.1.13). 
6.3.4.1.1.24 Slapdown of a loaded MSC following a drop from an overhead crane onto 
the edge of the trolley or pedestal during transfer of the MSC from the floor 
(after delivery by the MSC transporter) to the pedestal on a trolley 
This potential event is covered by Section 6.3.1.1.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 176 April 2005 
6.3.4.1.1.25 Drop or collision of handling equipment from an overhead bridge crane onto 
or against a loaded cask or MSC 
Operational requirements are assumed to ensure that a drop or collision of handling equipment 
onto or against a transportation cask without impact limiters or an MSC would not breach the 
cask (Assumption 5.1.1.30). 
6.3.4.1.1.26 Drop or collision of equipment from the maintenance crane onto or against a 
loaded cask or MSC 
Operational requirements are assumed to ensure that a drop or collision of handling equipment 
onto or against a transportation cask without impact limiters or an MSC would not breach the 
cask (Assumption 5.1.1.30). 
6.3.4.1.1.27 Collision of a trolley holding a cask or MSC on a pedestal with the shield 
doors separating the cask and MSC to trolley transfer room and the cask and 
MSC turntable room 
This potential event is included in Section 6.3.1.22. 
6.3.4.1.1.28 The shield doors separating the cask and MSC to trolley transfer room and 
the cask and MSC turntable room close on a trolley holding a loaded cask or 
MSC on a pedestal 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley holding 
a loaded cask or MSC would not overturn the trolley or cause it to drop its load (Assumption 
5.1.1.13). Because the trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.1.1.29 Derailment of a trolley holding a cask or MSC on a pedestal followed by a 
load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the cask to fall 
off the trolley (Assumption 5.1.1.36). 
6.3.4.1.2 Chemical Contamination/Flooding 
6.3.4.1.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed cask, this potential event will not occur 
unless an event sequence leads to exposure of SNF to air (BSC 2005 [DIRS 171428], Section 
6.6.3.1). Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to air. 
The consequence analyses will account for the possibility of oxidation, if applicable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 177 April 2005 
6.3.4.1.3 Explosion/Implosion 
6.3.4.1.3.1 Hydrogen explosion involving batteries on a cask trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.1.3.2 Hydrogen explosion involving batteries on a forklift 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.4.1.3.3 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.4.1.4 Fire, Thermal 
6.3.4.1.4.1 Electrical fire associated with the cask and MSC SRTC receipt area 
overhead cranes. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.2 Electrical fire associated with handling equipment or other electrical 
equipment in the cask and MSC entrance vestibule, cask and MSC SRTC 
receipt area, or the cask and MSC to trolley transfer room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.3 Diesel fuel fire/explosion involving an SRTC tractor pulling or pushing an 
SRTC holding a loaded cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.4 Diesel fuel fire/explosion involving an MSC transporter holding a loaded 
MSC 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 178 April 2005 
6.3.4.1.4.5 Fire/explosion (battery/electrical fire) associated with the cask trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.6 Fire/explosion (battery/electrical fire) associated with a forklift 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.7 Fire/explosion (battery/electrical fire) associated with a mobile elevated 
platform. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.8 Transient combustible fire in the cask and MSC SRTC receipt area, the cask 
and MSC entrance vestibule, or the cask and MSC to trolley transfer room. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.1.4.9 Thermal hazard (from decay heat) associated with a vertical orientation of a 
loaded cask. 
Transportation casks are designed to withstand normal conditions of transport (including high 
ambient temperatures and insolation) and hypothetical accident conditions (including fire) 
(Section 4.2.1). These conditions bound the thermal effect of orienting the cask vertically rather 
than horizontally. Therefore, this potential event will not lead to exposure of individuals to 
radiation because the waste is contained in a sealed cask (BSC 2005 [DIRS 171428], Section 
6.6.3.1). 
6.3.4.1.5 Radiation 
6.3.4.1.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. Consequence analysis will evaluate this hazard for 
event sequences and normal operations, as applicable. 
6.3.4.1.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.1.5.3 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 179 April 2005 
6.3.4.1.6 Fissile 
6.3.4.1.6.1 Criticality associated with an SRTC derailment or collision followed by a 
load tipover or fall and a rearrangement of cask internals 
A criticality in a transportation cask is not credible because design requirements and waste 
acceptance criteria will ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.4.1.6.2 Criticality associated with a cask drop, slapdown, or collision and 
rearrangement of cask internals. 
A criticality in a transportation cask is not credible because design requirements and waste 
acceptance criteria will ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.4.1.6.3 Criticality associated with an MSC drop, slapdown, or collision and 
rearrangement of cask internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.4.1.6.4 Criticality associated with an MSC transporter (holding a loaded MSC) 
collision followed by a load tipover or fall and rearrangement of the MSC 
internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.4.2 Cask/MSC Turntable Room, Cask Preparation Room 
6.3.4.2.1 Collision/Crushing 
6.3.4.2.1.1 Derailment of a trolley holding a cask or MSC on a pedestal (with outer 
and/or inner lid bolted in place, if applicable) followed by a load tipover or 
fall 
A design requirement is assumed to ensure that the cask-transfer trolley carrying transportation 
casks or MSCs in the DTF would not derail or allow the cask to fall off the trolley (Assumption 
5.1.1.36). 
6.3.4.2.1.2 Derailment of a trolley holding a cask or MSC on a pedestal (with outer 
and/or inner lid bolted in place, if applicable) due to a turntable malfunction 
followed by a load tipover or fall 
A design requirement is assumed to ensure that the cask-transfer trolley carrying transportation 
casks or MSCs in the DTF would not cause the trolley to derail or drop its load (Assumption
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 180 April 2005 
5.1.1.36). Because the transfer trolley remains upright there is no threat to the integrity of the 
cask. 
6.3.4.2.1.3 Collision of a trolley holding a cask or MSC on a pedestal (with outer and/or 
inner lid bolted in place, if applicable) with shield doors separating the 
cask/MSC turntable room and the cask preparation room 
This potential event is included in Section 6.3.1.22. 
6.3.4.2.1.4 Closure of the shield doors separating the cask/MSC turntable room and the 
cask preparation room onto the trolley holding a cask or MSC on a pedestal 
(with outer and/or inner lid bolted in place, if applicable) 
A design requirement is assumed to ensure that the airlock and shield doors cannot overturn the 
trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley remains upright 
there is no threat to the integrity of the cask. 
6.3.4.2.1.5 Collision involving two trolleys with at least one holding a cask or MSC on a 
pedestal (with outer and/or inner lid bolted in place, if applicable) 
This potential event is included in Section 6.3.1.22. 
6.3.4.2.1.6 Drop or collision of tools or equipment (including a lid-lifting fixture, lid 
bolts, etc.) onto or against a cask or MSC outer lid (if applicable) or a cask or 
MSC inner lid in the cask preparation room 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.4.2.1.7 Drop of a cask or MSC outer lid from the overhead crane onto the cask or 
MSC (if applicable) in the cask preparation room 
The frequency and consequences of this event are bounded by those of the Category 2 inner liddrop 
event sequence discussed in Section 6.3.1.2. The frequency is bounded because this event 
only applies to transportation casks and MSCs, while the bounding event also applies to WPs. 
The consequences are bounded because the contents of the cask are protected by the inner lid for 
this event, whereas no lids are in place for the bounding event. 
6.3.4.2.1.8 Drop or collision of a docking ring onto or against a cask or MSC in the cask 
preparation room 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 181 April 2005 
6.3.4.2.2 Chemical Contamination/Flooding 
6.3.4.2.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.2.3 Explosion/Implosion 
6.3.4.2.3.1 Cask purging or sampling system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.4.2.3.2 Explosion hazard associated with the cask sampling and purging system and 
the ignition of hydrogen that may have accumulated in the cask 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.4.2.3.3 Hydrogen explosion involving batteries on a trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.2.4 Fire, Thermal 
6.3.4.2.4.1 Electrical fire associated with the cask preparation area 20-ton overhead 
crane (in room 2051) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.2.4.2 Electrical fire associated with handling equipment or other cask preparation 
area equipment, including the turntable 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.2.4.3 Fire/explosion (battery/electrical fire) associated with the trolley. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 182 April 2005 
6.3.4.2.4.4 Transient combustible fire in the cask preparation room or the cask/MSC 
turntable room. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.2.4.5 Thermal hazard (from decay heat) associated with vertical orientation of the 
loaded cask. 
This potential hazard is addressed in Section 6.3.4.2.2.1 
6.3.4.2.4.6 Intact or non-intact SNF overheating or damage to cask or MSC contents 
due to a loss of cooling resulting in excessive temperature and possible 
zircaloy cladding (or other cladding) unzipping or cladding failure due to 
excessive hoop stresses. 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.2.5 Radiation 
6.3.4.2.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. Consequence analysis will evaluate this hazard for 
event sequences and normal operations, as applicable. 
6.3.4.2.5.2 Damage or rupture of cask sampling and purging system, leading to a release 
of cask or MSC internal gases and radioactive material 
The sampling operation will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses (BSC 2004 
[DIRS 172098], Section 3.2.2.1.1). Although a rupture leading to a radiological release would 
be an abnormal occurrence, radiation protection programs will ensure that such an occurrence 
would not contribute significantly to the normal operations dose. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.2.5.3 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Exposure of workers to radiation due to this potential event will be managed as a normaloperations 
dose by procedures for monitoring radiation doses and assigning work, which ensure 
that workers do not receive excessive radiation doses. See Section 7.4 for a list of potential 
events and conditions that are treated as normal operations.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 183 April 2005 
6.3.4.2.5.4 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.2.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.2.6 Fissile 
6.3.4.2.6.1 Criticality associated with a cask or MSC collision followed by a load tipover 
or fall and a rearrangement of the cask or MSC internals 
This potential event will be rendered Beyond Category 2 because design requirements and waste 
acceptance criteria will ensure criticality safety in transportation casks and MSCs (Assumption 
5.1.1.4) 
6.3.4.2.6.2 Criticality associated with a cask or MSC trolley derailment followed by a 
load tipover or fall and a rearrangement of the cask or MSC internals 
A criticality in an MSC is not credible because design requirements and waste acceptance criteria 
will ensure criticality safety in MSCs (Assumption 5.1.1.4). 
6.3.4.3 Cask and MSC Docking Room 
6.3.4.3.1 Collision/Crushing 
6.3.4.3.1.1 Derailment of a trolley holding a cask or MSC on a pedestal (with outer lid 
removed [if applicable] and inner lid unbolted but in place) followed by a 
load tipover or fall 
A design requirement is assumed to ensure that the cask-transfer trolley holding a loaded cask on 
a pedestal would not derail or allow the cask to fall off the trolley (Assumption 5.1.1.36). 
Because the trolley remains upright there will be no event sequence. 
6.3.4.3.1.2 Derailment of a trolley holding a cask or MSC on a pedestal (with outer lid 
removed [if applicable] and inner lid unbolted but in place) due to a 
turntable malfunction followed by a load tipover or fall 
This event is similar to the event discussed in Section 6.3.4.3.1.1 and the argument presented in 
that section applies here.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 184 April 2005 
6.3.4.3.1.3 Collision of a trolley holding a cask or MSC on a pedestal (with outer lid 
removed [if applicable] and inner lid unbolted but in place) with shield doors 
separating the cask preparation room and the cask/MSC turntable room or 
the shield doors separating the cask/MSC turntable room and the cask and 
MSC docking room 
This potential event is included in Section 6.3.1.22. 
6.3.4.3.1.4 Closure of the shield doors separating the cask preparation room and the 
cask/MSC turntable room or the shield doors separating the cask/MSC 
turntable room and the cask and MSC docking room onto the trolley holding 
a cask or MSC on a pedestal (with outer lid removed [if applicable] and inner 
lid unbolted but in place) 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley holding 
a loaded cask or MSC cannot overturn the trolley or cause it to drop its load (Assumption 
5.1.1.13). Because the trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.3.1.5 Collision involving two trolleys with at least one holding a cask or MSC on a 
pedestal (with outer lid removed [if applicable] and inner lid unbolted but in 
place) 
This potential event is included in Section 6.3.1.22. 
6.3.4.3.1.6 Drop or collision of a docking port (mobile slab) onto or against a cask or 
MSC 
A design requirement is assumed to ensure that this potential event will not initiate an event 
sequence (Assumption 5.1.1.17). 
6.3.4.3.1.7 Drop or collision of a docking port plug onto or against a cask lid or MSC lid 
(with outer lid removed [if applicable] and inner lid unbolted but in place) 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37). 
6.3.4.3.1.8 Drop of an inner lid into a cask or MSC (with outer lid removed [if 
applicable]) 
This potential event is included in Section 6.3.1.2. 
6.3.4.3.2 Chemical Contamination/Flooding 
6.3.4.3.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 185 April 2005 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.3.3 Explosion/Implosion 
6.3.4.3.3.1 Hydrogen explosion involving batteries on a cask trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.3.4 Fire, Thermal 
6.3.4.3.4.1 Electrical fire associated with handling equipment or other cask and MSC 
docking room equipment (including the turntables). 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.3.4.2 Fire/explosion (battery/electrical fire) associated with the cask trolley. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.3.4.3 Transient combustible fire in the cask and MSC docking room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.3.4.4 Thermal hazard (from decay heat) associated with vertical orientation of the 
loaded cask 
This potential hazard is addressed in Section 6.3.4.3.2.1. 
6.3.4.3.4.5 Intact or non-intact SNF overheating or damage to cask contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.3.5 Radiation 
6.3.4.3.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 186 April 2005 
6.3.4.3.5.2 Docking ring failure leads to radiological release 
This potential event is covered in Section 6.3.1.25. 
6.3.4.3.5.3 Radiological release due to installation of incorrect docking ring 
Docking ring failure has the same consequences as installation of an incorrect docking ring. 
Therefore, the analysis in Section 6.3.1.25 applies to this potential event. 
6.3.4.3.5.4 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.4.3.5.5 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.3.5.6 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.3.6 Fissile 
6.3.4.3.6.1 Criticality associated with cask or MSC collisions or a trolley derailment 
followed by a load tipover or fall and a rearrangement of cask or MSC 
internals 
A criticality in a transportation cask or MSC is not credible because design requirements and 
waste acceptance criteria will ensure criticality safety (Assumption 5.1.1.4). 
6.3.4.4 Empty WP and MSC processing prior to loading 
No potential event sequences have been identified that affect a waste form.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 187 April 2005 
6.3.4.5 Naval SNF Receipt: WP and Navy Cask Entrance Vestibule, WP/Navy Cask 
SRTC Receipt Area, WP/Navy to Trolley Transfer Room, WP/Navy Cask 
Preparation Room 
6.3.4.5.1 Collision/Crushing 
6.3.4.5.1.1 SRTC derailment involving a loaded naval SNF cask followed by a load 
tipover or fall 
A derailment is only a realistic possibility while the SRTC is in motion. The SRTC is not in 
motion after the impact limiters are removed (BSC 2005 [DIRS 171428], Section 6.6.3.5). 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask with impact limiters. To cover the case in which 
impact limiters have been removed, a design requirement will ensure that the SRTC will not 
derail and the cask will not fall off the SRTC (Assumption 5.1.1.35). Because the SRTC remains 
upright there is no threat to the integrity of the cask. 
6.3.4.5.1.2 Collision of an SRTC carrying a loaded naval SNF cask with the WP and 
navy cask entrance vestibule doors or the WP/navy cask SRTC receipt area 
shield doors 
A collision of the SRTC with doors is only a possibility while the SRTC is in motion. The 
SRTC is not in motion after the impact limiters are removed (BSC 2005 [DIRS 171428], Section 
6.6.3.5). Transportation casks with impact limiters are designed to withstand, without breaching, 
the drops discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that 
could occur during cask handling at the repository. Consequently, collision would not breach a 
transportation cask with impact limiters. 
6.3.4.5.1.3 The WP and navy cask entrance vestibule doors or the WP/navy cask SRTC 
receipt area shield doors close on an SRTC carrying a loaded cask 
A design requirement is assumed to ensure that closure of the entrance vestibule doors or shield 
doors onto an SRTC would not overturn the SRTC or cause it to drop its load (Assumption 
5.1.1.13). Because the SRTC remains upright there is no threat to the integrity of the cask. 
6.3.4.5.1.4 Collision of mobile elevated platforms with a loaded naval SNF cask during 
removal of personnel barriers and impact limiters or during survey activities 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.4.5.1.5 Forklift collision with a naval SNF cask on an SRTC (with or without impact 
limiters installed on the cask) or the SRTC holding the cask 
Operational requirements are assumed to ensure that forklifts will not be operated in a manner 
that could breach a transportation cask (Assumption 5.1.1.41). 
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 188 April 2005 
6.3.4.5.1.6 Drop or collision of personnel barriers or impact limiters from the receipt 
area crane onto or against a loaded naval SNF cask 
Operational requirements will ensure that equipment associated with cask preparation and 
handling will not breach the cask (Assumption 5.1.1.30). 
6.3.4.5.1.7 Slapdown of a loaded naval SNF cask onto an SRTC during upending of the 
loaded cask to the vertical orientation 
This potential event is covered by Section 6.3.1.1. 
6.3.4.5.1.8 Drop of a loaded naval SNF cask from the overhead crane onto the floor 
during the transfer from an SRTC to a pedestal previously positioned on a 
trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.4.5.1.9 Drop of a loaded naval SNF cask from the overhead crane onto a pedestal on 
a trolley during the transfer from an SRTC to a pedestal previously 
positioned on a trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.4.5.1.10 Drop or collision of a loaded cask from the overhead crane onto or against a 
sharp object during the transfer from an SRTC to a pedestal previously 
positioned on trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.5.1.11 Collision of a loaded naval SNF cask suspended from the overhead crane 
with the shield doors separating the WP/navy cask SRTC receipt area and 
the WP/navy to trolley transfer room during transfer of the naval SNF cask 
from the SRTC to the trolley 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.5.1.12 Closing of the shield doors separating the WP/navy cask SRTC receipt area 
and the WP/navy to trolley transfer room (striking the cask while the loaded 
cask is suspended from the overhead crane) during the transfer of the cask 
from the SRTC to the trolley 
A design requirement is assumed to ensure that closure of the shield doors onto a cask suspended 
from the overhead crane cannot breach the cask or cause the crane to drop the load (Assumption 
5.1.1.13).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 189 April 2005 
6.3.4.5.1.13 Slapdown of a loaded naval SNF cask following a drop from the overhead 
crane onto the edge of the trolley or pedestal during transfer of the cask from 
the SRTC to the trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.4.5.1.14 Drop or collision of handling equipment from the overhead bridge crane 
onto or against a loaded naval SNF cask 
Operational requirements will ensure that a drop of handling equipment onto a transportation 
cask without impact limiters will not breach the cask (Assumption 5.1.1.30). 
6.3.4.5.1.15 Drop or collision of other miscellaneous (non-handling) equipment (gassampling, 
lid bolt removal, etc.) from the overhead bridge crane onto or 
against a loaded naval SNF cask 
Operational requirements will prevent cask breach for this potential event (Assumption 5.1.1.30). 
6.3.4.5.1.16 Collision of a trolley holding a naval SNF cask on a pedestal with shield 
doors separating the WP/navy to trolley transfer room and the WP/navy 
cask preparation room 
This potential event is included in Section 6.3.1.22. 
6.3.4.5.1.17 Closing of the shield doors separating the WP/navy to trolley transfer room 
and the WP/navy cask preparation room on a trolley holding a naval SNF 
cask on a pedestal 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley holding 
a loaded cask or MSC would not overturn the trolley or cause it to drop its load (Assumption 
5.1.1.13). Because the trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.5.1.18 Derailment of a trolley holding a naval SNF cask on a pedestal followed by a 
load tipover or fall 
A design requirement is assumed to ensure that the cask-transfer trolley holding a loaded cask on 
a pedestal would not derail or allow the cask to fall off the trolley (Assumption 5.1.1.36). 
Because the transfer trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.5.2 Explosion/Implosion 
6.3.4.5.2.1 Hydrogen explosion involving batteries on a forklift 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 190 April 2005 
6.3.4.5.2.2 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.5.3 Fire, Thermal 
6.3.4.5.3.1 Electrical fire associated with the WP/navy cask SRTC receipt area overhead 
cranes 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.5.3.2 Electrical fire associated with handling equipment or other electrical 
equipment in the WP/navy cask SRTC receipt area, WP and navy cask 
entrance vestibule, the WP/navy to trolley transfer room, or the WP/navy 
cask preparation room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.5.3.3 Diesel fuel fire/explosion involving an SRTC tractor pulling or pushing an 
SRTC holding a naval SNF cask containing a naval SNF canister 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.5.3.4 Electrical fire associated with a trolley holding a naval SNF cask containing a 
naval SNF canister. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.5.3.5 Fire/explosion (battery/electrical fire) associated with a forklift. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.5.3.6 Fire/explosion (battery/electrical fire) associated with a mobile elevated 
platform. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 191 April 2005 
6.3.4.5.3.7 Transient combustible fire in the WP and navy cask entrance vestibule, the 
WP/navy cask SRTC receipt area, the WP/navy to trolley transfer room, or 
the WP/navy cask preparation room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.5.3.8 Thermal hazard (from decay heat) associated with a vertical orientation of a 
loaded naval SNF cask 
This potential event will not cause oxidation of SNF leading to exposure of individuals to 
radiation because the naval SNF is contained in sealed canisters (BSC 2005 [DIRS 171428], 
Section 6.6.3.5). 
6.3.4.5.4 Radiation 
6.3.4.5.4.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.4.5.4.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.5.4.3 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.5.5 Fissile 
6.3.4.5.5.1 Criticality associated with an SRTC derailment or collision followed by a 
load tipover or fall and a rearrangement of the naval SNF cask internals 
Naval casks are moved on the SRTC with impact limiters in place. Transportation casks with 
impact limiters are designed to withstand, without breaching, the drops discussed in Section 
4.2.1. A criticality in the naval SNF receipt area is not credible because design requirements and 
waste acceptance criteria will ensure criticality safety in transportation casks (Assumption 
5.1.1.4). 
6.3.4.5.5.2 Criticality associated with a naval SNF cask drop, slapdown, or collision and 
rearrangement of cask internals 
A criticality in the naval SNF receipt area is not credible because design requirements and waste 
acceptance criteria will ensure criticality safety in transportation casks (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 192 April 2005 
6.3.4.5.5.3 Criticality associated with naval SNF cask trolley derailment followed by a 
load tipover or fall and a rearrangement of the cask internals 
A design requirement is assumed to ensure that the cask-transfer trolley carrying transportation 
casks or MSCs in the DTF would not derail or allow the cask to fall off the trolley (Assumption 
5.1.1.36). 
6.3.4.6 Naval SNF Processing: WP Docking Cell, WP Loading (Navy 
Canister)/Docking Ring Removal Cell, WP Loading/Docking Ring Removal Cell 
6.3.4.6.1 Collision/Crushing 
6.3.4.6.1.1 Derailment of a trolley holding a loaded naval SNF cask on a pedestal 
followed by a load tipover or fall 
A design requirement is assumed to ensure that the cask-transfer trolley holding a loaded cask on 
a pedestal would not derail or allow the cask to fall off the trolley (Assumption 5.1.1.36). 
Because the transfer trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.6.1.2 Drop or collision of handling equipment (such as the lid grapple) onto or 
against a naval SNF cask outer lid (if applicable) or inner lid 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.4.6.1.3 Drop of a naval SNF cask inner lid (if applicable) from the 70-ton navy 
canister handling crane onto a naval SNF canister 
After the inner lid of a transportation cask is removed, the lid could be dropped back into the 
opening of the cask. If the lid rotates before impact, its edge could strike the naval canister. This 
potential event is included in Section 6.3.1.2. 
6.3.4.6.1.4 Drop or collision of handling equipment (such as a canister grapple) into or 
against an open naval SNF cask loaded with a naval SNF canister 
This potential event is included in the generalized handling-equipment drop in Section 6.3.1.6. 
6.3.4.6.1.5 Drop or collision of a naval SNF canister from the WP docking cell crane 
back into or against the naval SNF cask being unloaded 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.6.1.6 Fall of a naval SNF canister from the WP docking crane onto the edge of the 
cask, the edge of the WP, or the edge of the transfer floor, followed by a 
slapdown of the canister 
This potential event is included in Section 6.3.1.5.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 193 April 2005 
6.3.4.6.1.7 Drop or collision of a naval SNF canister from the 70-ton navy canister 
handling crane onto or against a sharp object 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.6.1.8 Collision involving a naval SNF canister suspended from the 70-ton navy 
canister handling crane with equipment located in the WP docking cell or the 
WP loading (navy canister)/docking ring removal cell, such as lid lifting 
equipment 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.6.1.9 Drop of a naval SNF canister from the 70-ton navy canister handling crane 
onto the navy transfer/docking ring removal cell floor 
This potential event is included in Section 6.3.1.5. 
6.3.4.6.1.10 Impact due to horizontal movement of the naval SNF canister before it is 
completely removed from the naval transportation cask 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.6.1.11 Drop or collision of a naval SNF canister from the 70-ton navy canister 
handling crane into or against the WP 
This potential event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.6.1.12 Drop or collision of handling equipment into or against an open WP loaded 
with a naval SNF canister 
This potential event is included in Section 6.3.1.6. 
6.3.4.6.1.13 Drop of a WP inner lid from the WP docking cell crane into a loaded naval 
WP 
The calculation in Section 6.3.1.2 includes this potential event. 
6.3.4.6.2 Explosion/Implosion 
No explosion/implosion events in this area.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 194 April 2005 
6.3.4.6.3 Fire, Thermal 
6.3.4.6.3.1 Electrical fire associated with SNF handling equipment in the WP docking 
cell, and the WP loading (naval SNF canister)/docking ring removal cell 
(including the overhead cranes, etc.). 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.6.3.2 Electrical fire associated with the trolley holding either a loaded, unsealed 
WP or a loaded naval SNF cask holding a naval SNF canister. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.6.3.3 Thermal hazard (from decay heat) associated with a vertical orientation of 
the naval SNF cask. 
This potential event will not cause oxidation of SNF leading to exposure of individuals to 
radiation because naval SNF is handled in sealed canisters (BSC 2005 [DIRS 171428], Section 
6.6.3.6). 
6.3.4.6.3.4 Overheating of a loaded, unsealed (and uninerted) cask or WP due to a loss 
of cooling resulting in excessive temperature and possible damage to canister 
contents 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.6.3.5 Transient combustible fire in the WP docking cell, or the WP loading (naval 
SNF canister)/docking ring removal cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.6.4 Radiation 
6.3.4.6.4.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.4.6.4.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 195 April 2005 
6.3.4.6.4.3 Inadvertent opening of a shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.4.6.4.4 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.6.5 Fissile 
6.3.4.6.5.1 Criticality associated with a naval SNF cask drop, slapdown, or collision and 
rearrangement of cask internals 
A criticality in a transportation cask is not credible because design requirements and waste 
acceptance criteria will ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.4.7 Cask and MSC Docking Room, Waste Transfer Cell, WP Docking Cell, WP 
Loading/Docking Ring Removal Cell 
6.3.4.7.1 Collision/Crushing 
6.3.4.7.1.1 Drop or collision of handling equipment into or against an open cask or open 
MSC loaded with commercial SNF assemblies, a DOE HLW canister, a DOE 
SNF MCO, or a [standardized] DOE SNF canister 
Drops of handling equipment onto non-SNF assembly canisters are treated in Section 6.3.1.6. 
Drops of handling equipment onto CSNF assemblies are treated in Section 6.3.1.4. 
6.3.4.7.1.2 Drop or collision of an SNF assembly from the spent fuel transfer machine 
back into or against a cask or MSC being unloaded 
This event is included in Section 6.3.1.3. 
6.3.4.7.1.3 Drop or collision of an SNF assembly from the spent fuel transfer machine 
back onto or against one or more SNF assembly(ies) in a cask or MSC 
The calculation in Section 6.3.1.3 includes this potential event as part of a generalized Category 
1 event sequence. The generalized drop and collision events discussed in Section 6.3.1.3 include 
assembly drops and collisions in the DTF.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 196 April 2005 
6.3.4.7.1.4 Impact due to horizontal movement of an SNF assembly by the spent fuel 
transfer machine before the assembly is completely removed from the cask 
or MSC 
This potential event is a collision between the assembly and the wall of the basket structure in 
the cask. Assembly collisions are included in Section 6.3.1.3. 
6.3.4.7.1.5 Drop of an SNF assembly from the spent fuel transfer machine onto the 
waste transfer cell floor 
The calculation in Section 6.3.1.3 includes this potential event as part of a generalized Category 
1 event sequence. 
6.3.4.7.1.6 Collision involving an SNF assembly suspended from the spent fuel transfer 
machine with equipment located in the waste transfer cell or on the cell floor 
(such as lid lifting equipment) 
The calculation in Section 6.3.1.3 includes this potential event as part of a generalized Category 
1 event sequence. 
6.3.4.7.1.7 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against a sharp object 
Assemblies are assumed to breach when they are dropped or involved in a collision. The 
calculation in Section 6.3.1.3 includes the potential event. 
6.3.4.7.1.8 Drop or collision of an SNF assembly from the spent fuel transfer machine 
into or against an empty WP or MSC being loaded 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.7.1.9 Drop and slapdown of an SNF assembly from the spent fuel transfer machine 
(due to impact with an edge of the cask, MSC, WP, floor edge, WP internal 
baffle, staging rack, etc.) during the transfer from the cask or MSC to a WP, 
or staging rack 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.7.1.10 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against another SNF assembly in a WP or MSC 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.7.1.11 Drop or collision of an SNF assembly from the spent fuel transfer machine 
into or against an empty staging rack in the waste transfer cell 
The calculation in Section 6.3.1.3 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 197 April 2005 
6.3.4.7.1.12 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against one or more SNF assemblies in a staging rack 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.7.1.13 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against a DOE HLW canister or [standardized] DOE SNF canister in 
a staging rack 
An operational requirement is assumed to preclude contact between a CSNF assembly and a 
staged canister (Assumption 5.1.4.1). 
6.3.4.7.1.14 Drop or collision of a DOE HLW canister, a [standardized] DOE SNF 
canister, from the waste transfer cell overhead crane back into or against the 
cask or MSC being unloaded 
This potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.15 Drop or collision of a DOE SNF MCO from the waste transfer cell overhead 
crane back into or against the cask being unloaded 
This potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.16 Impact due to horizontal movement of a DOE HLW canister, or a 
[standardized] DOE SNF canister with the waste transfer cell overhead crane 
before the canister is completely removed from the cask or MSC 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.7.1.17 Impact due to horizontal movement of a DOE SNF MCO with the waste 
transfer cell overhead crane before the canister is completely removed from 
the cask 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.7.1.18 Drop and slapdown of a DOE HLW canister or a [standardized] DOE SNF 
canister from the waste transfer cell overhead crane (due to impact with an 
edge of the cask, MSC, WP, floor edge, WP internal baffle, staging rack, etc.) 
during the transfer from the cask or MSC to a WP, or staging rack 
Section 6.3.1.5 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 198 April 2005 
6.3.4.7.1.19 Drop and slapdown of a DOE SNF MCO from the waste transfer cell 
overhead crane (due to impact with an edge of the cask, WP, floor edge, WP 
internal baffle, etc.) during the transfer from the cask to a WP 
Section 6.3.1.5 includes this potential event. 
6.3.4.7.1.20 Drop or collision of a DOE HLW canister, a [standardized] DOE SNF 
canister, or a DOE SNF MCO from the waste transfer cell overhead crane 
onto or against a sharp object. 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.7.1.21 Collision involving a DOE HLW canister, a [standardized] DOE SNF 
canister, or a DOE SNF MCO suspended from the waste transfer cell 
overhead crane with equipment located in the waste transfer cell or on the 
cell floor, such as lid lifting equipment. 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.7.1.22 Drop of a DOE HLW canister, a [standardized] DOE SNF canister, or a 
DOE SNF MCO from the waste transfer cell overhead crane onto the waste 
transfer cell floor. 
Section 6.3.1.5 includes this potential event. 
6.3.4.7.1.23 Drop or collision of a DOE HLW canister or a [standardized] DOE SNF 
canister from the waste transfer cell crane into or against an empty canister 
staging rack 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.24 Drop or collision of a DOE HLW canister or a [standardized] DOE SNF 
canister from the waste transfer cell crane into or against an SNF assembly 
staging rack loaded with SNF assemblies 
An operational requirement will prohibit carrying canisters over or near staging racks for CSNF 
(Assumption 5.1.4.4). Therefore, this potential event is not considered further. 
6.3.4.7.1.25 Drop or collision of a DOE HLW canister or a [standardized] DOE SNF 
canister from the waste transfer cell crane onto or against another DOE 
HLW canister or [standardized] DOE SNF canister in a staging rack 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 199 April 2005 
6.3.4.7.1.26 Drop or collision of a DOE HLW canister, or a [standardized] DOE SNF 
canister from the waste transfer cell crane into or against an empty WP or 
into or against an empty MSC being loaded 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.27 Drop or collision of a DOE SNF MCO from the waste transfer cell crane into 
or against an empty WP being loaded 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.28 Drop or collision of a DOE HLW canister from the waste transfer cell crane 
onto or against another DOE HLW canister, a [standardized] DOE SNF 
canister, or a DOE SNF MCO in a WP being loaded 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.29 Drop or collision of a DOE HLW canister from the waste transfer cell crane 
onto or against another DOE HLW canister or a [standardized] DOE SNF 
canister in a WP or in an MSC being loaded 
Section 6.3.1.5 includes this potential event. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.30 Drop or collision of a [standardized] DOE SNF canister from the waste 
transfer cell crane onto or against a DOE HLW canister in a WP or in an 
MSC 
Dropping a DOE SNF canister onto a DOE HLW canister is rendered Beyond Category 2 by an 
operational requirement not to transfer the DOE SNF canister into the WP if there are one or 
more DOE HLW canisters present in the WP or MSC (Assumption 5.1.1.23). Crane-load 
collisions do not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.31 Drop or collision of a DOE SNF MCO from the waste transfer cell crane onto 
or against another DOE SNF MCO or a DOE HLW canister in a WP being 
loaded 
Drop of a DOE SNF MCO from above its lift-height limit is Beyond Category 2, as shown in 
Table 18, Event F. If a DOE SNF MCO is dropped onto another MCO within the lift-height 
limit, neither MCO will breach (Assumption 5.1.1.28). Dropping a DOE SNF MCO onto a DOE 
HLW canister is rendered Beyond Category 2 by an operational requirement not to transfer the 
DOE SNF canister into the WP if there are one or more DOE HLW canisters present in the WP 
or MSC (Assumption 5.1.1.23). Crane-load collisions do not initiate Category 1 or Category 2 
event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 200 April 2005 
6.3.4.7.1.32 Drop or collision of a [standardized] DOE SNF canister from the waste 
transfer cell crane onto or against another [standardized] DOE SNF canister 
in a WP or in an MSC in a misload situation 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.33 Drop or collision of a DOE SNF MCO from the waste transfer cell crane onto 
or against a [standardized] DOE SNF canister in a WP in a misload situation 
Section 6.3.1.5 includes this potential drop event. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.7.1.34 Drop or collision of a DOE HLW canister, a [standardized] DOE SNF 
canister, or a DOE SNF MCO from the waste transfer cell crane onto or 
against SNF assemblies in a WP or in an MSC in a misload situation 
This potential event requires, in addition to a drop or collision, an attempt to load a canister into 
a WP or MSC designed for bare CSNF assemblies. An operational requirement will prevent this 
misload situation (Assumption 5.1.1.27). 
6.3.4.7.1.35 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against a DOE HLW canister or a [standardized] DOE SNF canister, 
in a WP or in an MSC in a misload situation 
This potential event is unlikely because it requires, in addition to a drop or collision, an attempt 
to load a CSNF assembly into a WP or MSC designed for canisters. An operational requirement 
will prevent this misload situation (Assumption 5.1.1.26). 
6.3.4.7.1.36 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against a DOE HLW canister, or a DOE SNF MCO in a WP in a 
misload situation 
This potential event is unlikely because it requires, in addition to a dropped assembly, an attempt 
to load a CSNF assembly into a WP or MSC designed for canisters. An operational requirement 
will prevent this misload situation (Assumption 5.1.1.26). 
6.3.4.7.1.37 Drop or collision of handling equipment onto or against SNF assemblies in 
the SNF staging rack 
Drops of handling equipment onto CSNF assemblies are treated in Section 6.3.1.4. 
6.3.4.7.1.38 Drop or collision of handling equipment onto or against a DOE HLW 
canister or a [standardized] DOE SNF canister in a canister staging rack 
This event is included in Section 6.3.1.6.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 201 April 2005 
6.3.4.7.1.39 Drop or collision of handling equipment into or against an open MSC or an 
open WP filled with SNF assemblies 
Drops of handling equipment onto CSNF assemblies are treated in Section 6.3.1.4. 
6.3.4.7.1.40 Drop or collision of handling equipment into or against an open WP loaded 
with SNF assemblies, DOE HLW canisters, and/or a [standardized] DOE 
SNF canister, and/or DOE SNF MCOs 
This event is included in Section 6.3.1.6. 
6.3.4.7.1.41 Drop or collision of a WP inner lid or MSC cask inner lid from the docking 
station crane onto or against a loaded WP or loaded MSC 
This event is included in Section 6.3.1.2. 
6.3.4.7.1.42 Drop or collision of a WP docking port plug from the waste transfer cell 
crane onto or against the inner lid of a loaded WP or loaded MSC (with lid in 
place but not sealed) 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37). 
6.3.4.7.1.43 Drop or collision of a WP docking ring onto or against a loaded WP (with lid 
in place but not sealed) during docking ring removal in the WP 
loading/docking ring removal cell 
The inner lid is in place for this potential event. Operational requirements will prevent 
radiological releases due to this potential event (Assumption 5.1.3.3). 
6.3.4.7.1.44 Drop or collision of a handling or other miscellaneous equipment onto or 
against a loaded WP (with lid in place but not sealed) during docking ring 
removal in the WP loading/docking ring removal cell 
The inner lid is in place for this potential event. Operational requirements will prevent 
radiological releases due to this potential event (Assumption 5.1.3.3). 
6.3.4.7.1.45 Derailment of a trolley holding a loaded, unsealed WP (with lid in place but 
not sealed) followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley carrying a WP would not derail or 
allow the WP to fall off the trolley (Assumption 5.1.1.36).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 202 April 2005 
6.3.4.7.2 Chemical Contamination/Flooding 
6.3.4.7.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.7.3 Explosion/Implosion 
6.3.4.7.3.1 Hydrogen explosion involving batteries on a cask trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.7.4 Fire, Thermal 
6.3.4.7.4.1 HEPA filter fire due to excessive radioactive decay within the filter bed. 
HEPA filters will be maintained well below their auto-ignition temperature to preclude a filter 
fire (Assumption 5.1.1.47). 
6.3.4.7.4.2 Electrical fire associated with SNF and HLW handling equipment or other 
electrically-powered equipment in the waste transfer cell, the WP docking 
cell, or the WP loading/docking ring removal cell (including the overhead 
cranes and the spent fuel transfer machine) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.7.4.3 Fire/explosion (battery/electrical fire) associated with a cask trolley holding 
an unsealed, partially filled or filled cask or MSC 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.7.4.4 Electrical fire associated with a WP trolley holding an unsealed, partiallyfilled 
or filled WP 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 203 April 2005 
6.3.4.7.4.5 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses. 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.7.4.6 Transient combustible fire in the cask and MSC docking room, waste 
transfer cell, the WP docking cell, or the WP loading/docking ring removal 
cell. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.7.5 Radiation 
6.3.4.7.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.4.7.5.2 Docking ring failure leads to a radiological release 
This potential event is covered in Section 6.3.1.25. 
6.3.4.7.5.3 Radiological release due to installation of incorrect docking ring 
Docking ring failure has the same consequences as installation of an incorrect docking ring. 
Therefore, the analysis in Section 6.3.1.25 applies to this potential event. 
6.3.4.7.5.4 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne 
contamination 
This potential event is covered in Section 6.3.1.25. 
6.3.4.7.5.5 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 204 April 2005 
6.3.4.7.5.6 Inadvertent opening of a shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.4.7.5.7 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.7.6 Fissile 
6.3.4.7.6.1 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine into a cask, MSC, or WP and a rearrangement of the cask, 
MSC, or WP internals 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumptions 5.1.1.4, 5.1.3.1, and 5.1.3.2). 
6.3.4.7.6.2 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine and a rearrangement of the fuel rods that comprise the 
assembly due to impact 
The analysis Surface Facility Criticality Safety Calculations (BSC 2004 [DIRS 168132], Section 
5.2.3.1) determined that a drop of two CSNF assemblies does not pose a criticality safety 
concern. This result ensures that drops, collisions, and other handling impacts of a CSNF 
assembly (allowing for rearrangement of fuel rods and without credit for burnup or moderator 
control) does not pose a criticality safety concern (see Section 4.1.10). 
6.3.4.7.6.3 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine onto the storage racks and a rearrangement of the 
orientation of the SNF assemblies in the storage racks 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumptions 5.1.4.3). 
6.3.4.7.6.4 Criticality associated with a drop or slapdown of a [standardized] DOE SNF 
canister, a DOE SNF MCO, or a DOE HLW canister 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumptions 5.1.1.4, 5.1.3.2, and 5.1.1.3). There is no potential for criticality of HLW 
canisters (Assumption 5.2.1.19).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 205 April 2005 
6.3.4.7.6.5 Criticality associated with the drop of heavy equipment onto a loaded, 
unsealed cask, MSC, or WP and a rearrangement of the container internals 
Equipment drop onto a transportation cask or MSC will not lead to a criticality because design 
requirements and waste acceptance criteria will ensure criticality safety (Assumption 5.1.1.4). 
Equipment drop onto a WP will not lead to criticality because (1) a design requirement will 
ensure that WPs are subcritical provided that moderator control is in effect (Assumptions 5.1.3.2 
and 5.1.1.21) and (2) design features of the WP will ensure that an unsealed WP suffering an 
impact from heavy equipment drop will not become critical (Assumptions 5.1.3.2). 
6.3.4.7.6.6 Criticality associated with a misload of a WP or an MSC 
WPs are designed such that no combination of CSNF assemblies that may be accepted for 
disposal could lead to a nuclear criticality inside the WP during preclosure provided that 
moderator control is in effect (Assumptions 5.1.3.2 and 5.1.1.21). MSCs will be designed to 
remain subcritical with the most reactive commercial CSNF assemblies and optimal moderation 
(Assumption 5.1.1.4). Therefore, a preclosure criticality due to misload is not credible and 
administrative controls on container loading are not relied upon to prevent preclosure criticality. 
6.3.4.7.6.7 Criticality associated with a misload of a commercial SNF staging rack 
Criticality due to misload will be rendered Beyond Category 2 because a design requirement will 
ensure that the staging racks with moderator control can be loaded to capacity with the most 
reactive CSNF assemblies without causing a nuclear criticality (Assumption 5.1.4.2). 
6.3.4.7.6.8 Criticality associated with a misload of a canister staging rack 
Criticality due to misload will be rendered Beyond Category 2 because a design requirement will 
ensure that the most reactive configuration of standardized DOE SNF canisters can be loaded 
into DOE SNF staging racks (with moderator control) without causing a nuclear criticality 
(Assumption 5.1.1.2). An operational requirement is assumed to ensure that CSNF assemblies 
are not loaded into the canister staging rack in the DTF (Assumption 5.1.4.1). Neither MCOs 
nor naval canisters will be staged (Assumption 5.2.1.20). There is no potential for criticality of 
HLW canisters (Assumption 5.2.1.19).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 206 April 2005 
6.3.4.8 Empty Transportation Cask/MSC/DPC Removal: Cask and MSC Docking 
Room, Cask/MSC Turntable Room, Cask Restoration Room, Cask and MSC to 
Trolley Transfer Room, Cask and MSC SRTC Receipt Area, Cask and MSC 
Entrance Vestibule 
6.3.4.8.1 Radiation 
6.3.4.8.1.1 Radiation exposure of a facility worker 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.4.8.1.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.8.2 Fissile 
6.3.4.8.2.1 Criticality associated with the collection and concentration of fissile material 
collected from casks during cask restoration activities 
An operational requirement will ensure that radioactive contamination that is collected during 
cleanup activities in transfer cells is handled in a manner that precludes nuclear criticality 
(Assumption 5.1.1.64). 
6.3.4.9 Loaded MSC Removal: Cask and MSC Docking Room, Cask/MSC Turntable 
Room, Cask Preparation Room, Cask and MSC to Trolley Transfer Room, 
Cask and MSC SRTC Receipt Area, Cask and MSC Entrance Vestibule 
6.3.4.9.1 Collision/Crushing 
6.3.4.9.1.1 Derailment of a trolley holding a loaded MSC on a pedestal followed by a 
load tipover or fall (before or after the outer lid [as applicable] is fastened) 
A design requirement is assumed to ensure that the trolley carrying an MSC would not derail or 
allow the MSC to fall off the trolley (Assumption 5.1.1.36). Because the trolley remains upright 
there is no threat to the integrity of the cask. 
6.3.4.9.1.2 Derailment of a trolley holding a loaded MSC on a pedestal due to a 
turntable malfunction followed by a load tipover or fall (before or after the 
outer lid [as applicable] is fastened) 
A design requirement is assumed to ensure that the cask-transfer trolley carrying a transportation 
cask or MSC in the DTF would not derail or allow the cask to fall off the trolley (Assumption 
5.1.1.36). Because the transfer trolley remains upright there is no threat to the integrity of the 
cask. 
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 207 April 2005 
6.3.4.9.1.3 Collision of a trolley holding a loaded MSC on a pedestal with shield doors 
separating the cask and MSC docking room and the cask/MSC turntable 
room or the cask/MSC turntable room and the cask preparation room 
(before or after the outer lid [as applicable] is fastened) 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.9.1.4 Closure of the shield doors separating the cask and MSC docking room and 
the cask/MSC turntable room or the cask/MSC turntable room and the cask 
preparation room onto the trolley holding a loaded MSC on a pedestal 
(before or after the outer lid [as applicable] is fastened) 
A design requirement is assumed to ensure that closure of the airlock and shield doors onto a 
trolley would not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because 
the trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.9.1.5 Collision involving two trolleys holding casks on pedestals (including a 
loaded MSC) (before or after the outer lid [as applicable] is fastened) 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.9.1.6 Drop or collision of tools or equipment (including the outer lid-lifting fixture, 
inner lid-lifting fixture, lid bolts, etc.) onto or against an MSC inner lid or 
outer lid, as applicable, during the MSC lid fastening process 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.4.9.1.7 Drop of an MSC outer lid from the overhead crane onto the loaded MSC 
inner lid, as applicable 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event sequence discussed in Section 6.3.1.2. The frequency is bounded because the bounding 
event applies to WPs, MSCs, and transportation casks, but this event applies only to MSCs. The 
consequences are bounded because the contents of the MSC are protected by the inner lid, 
whereas no lids are in place for the bounding event. An operational requirement is assumed to 
ensure that the outer-lid drop will not breach a DOE SNF canister inside (Assumption 5.1.1.44). 
6.3.4.9.1.8 Drop or collision of a docking ring onto or against a loaded MSC 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.4.9.1.9 Collision of a trolley holding a loaded, sealed MSC on a pedestal with shield 
doors separating cask/MSC turntable room and the cask and MSC to trolley 
transfer room 
Trolley collision is addressed in Section 6.3.1.22.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 208 April 2005 
6.3.4.9.1.10 Closure of the shield doors separating cask/MSC turntable room and the 
cask and MSC to trolley transfer room onto the trolley holding a loaded, 
sealed MSC on a pedestal 
A design requirement is assumed to ensure that closure of the airlock and shield doors onto a 
trolley would not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because 
the trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.9.1.11 Drop of a loaded, sealed MSC from the overhead crane onto the floor during 
the transfer of the MSC from a pedestal staged on a trolley to the floor in the 
lay-down area in the cask and MSC SRTC receipt area 
This potential event is covered by Section 6.3.1.1.2. 
6.3.4.9.1.12 Drop or collision of a loaded MSC from the overhead crane onto or against a 
sharp object during the transfer of the MSC from a pedestal staged on a 
trolley to the floor in the lay-down area in the cask and MSC SRTC receipt 
area 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.9.1.13 Slapdown of a loaded, sealed MSC following a drop onto the edge of the 
pedestal, trolley, railcar or other object during the transfer of the MSC from 
a pedestal staged on a trolley to the floor in the lay-down area in the cask and 
MSC SRTC receipt area 
This potential event is covered by Section 6.3.1.1.2. 
6.3.4.9.1.14 Drop or collision of handling equipment from the overhead bridge crane 
onto or against a loaded MSC 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.4.9.1.15 Drop or collision of equipment from the 25-ton material handling crane onto 
or against a loaded, sealed MSC 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.4.9.1.16 Forklift collision with a loaded, sealed MSC on a pedestal on a trolley, an 
MSC positioned on the floor in the lay-down area in the cask and MSC 
SRTC receipt area, or with the MSC transporter holding the MSC 
Operational requirements are assumed to ensure that forklifts will not be operated in a manner 
that could breach an MSC (Assumption 5.1.1.41).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 209 April 2005 
6.3.4.9.1.17 Mobile elevated platform collision with a loaded, sealed MSC on a pedestal 
on a trolley, an MSC positioned on the floor in the lay-down area in the cask 
and MSC SRTC receipt area, or with the MSC transporter holding the MSC 
Operational requirements are assumed to ensure that the platform will not be operated in a 
manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.4.9.1.18 Drop of a loaded MSC from the MSC transporter onto the floor inside the 
DTF while in-transit to the SNF Aging System 
Item S.12, (Section 4.1.11) addresses this potential event sequence. 
6.3.4.9.1.19 Drop or collision of a loaded MSC from the MSC transporter onto or against 
a sharp object inside the DTF while in-transit to the SNF Aging System 
Item S.12, S.23, and S.26 (Section 4.1.11) addresses this potential event sequence. 
6.3.4.9.1.20 MSC transporter collision while carrying a loaded, sealed MSC followed by 
an MSC tipover or fall. 
Nuclear safety design approaches S.23, S.24, S.25, and S.26 (Section 4.1.11) address this 
potential event sequence. 
6.3.4.9.1.21 MSC transporter collision into a loaded, sealed MSC followed by an MSC 
tipover or fall 
Nuclear safety design approaches S.23, S.24, S.25, and S.26 (Section 4.1.11) address this 
potential event sequence. 
6.3.4.9.1.22 Collision of the MSC transporter (holding a loaded, sealed MSC) with the 
cask and MSC SRTC receipt area shield doors or the cask and MSC 
entrance vestibule doors 
A design or operational requirement is assumed to ensure that a collision of the MSC transporter 
with the MSC SRTC receipt area shield doors or the cask and MSC entrance vestibule doors 
would not overturn the MSC transporter or cause it to drop its load (Assumption 5.1.1.38). 
Because the MSC transporter remains upright there is no threat to the integrity of the cask. 
6.3.4.9.1.23 The cask and MSC SRTC receipt area shield doors or the cask and MSC 
entrance vestibule doors close on the MSC transporter holding a loaded, 
sealed MSC 
A design requirement is assumed to ensure that closure of the entrance vestibule doors or receipt 
area shield doors onto the MSC transporter holding a loaded, sealed MSC would not overturn the 
MSC transporter or cause it to drop its load (Assumption 5.1.1.13). Because the MSC 
transporter remains upright there is no threat to the integrity of the cask.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 210 April 2005 
6.3.4.9.2 Chemical Contamination/Flooding 
6.3.4.9.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.9.3 Explosion/Implosion 
6.3.4.9.3.1 MSC inerting system (or other pneumatic or pressurized system) missile due 
to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.4.9.3.2 Hydrogen explosion involving batteries on a cask trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.9.3.3 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.9.3.4 Hydrogen explosion involving batteries on a forklift 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.9.3.5 Explosion hazard associated with the cask purging system and the ignition of 
hydrogen that may have accumulated in the cask prior to MSC purging and 
inerting 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 211 April 2005 
6.3.4.9.4 Fire, Thermal 
6.3.4.9.4.1 Electrical fire associated with the overhead cranes, including those located in 
the cask and MSC docking room, and the cask and MSC SRTC receipt area 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.9.4.2 Electrical fire associated with handling equipment or other equipment 
located in the cask and MSC docking room, cask/MSC turntable room, cask 
and MSC to trolley transfer room, cask preparation room, cask and MSC 
SRTC receipt area, or the cask and MSC entrance vestibule (including the 
turntables) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.9.4.3 Transient combustible fire in the cask and MSC docking room, cask/MSC 
turntable room, cask preparation room, cask and MSC to trolley transfer 
room, cask and MSC SRTC receipt area, or the cask and MSC entrance 
vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.9.4.4 Fire/explosion (battery/electrical fire) associated with the cask trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.9.4.5 Fire/explosion (battery/electrical fire) associated with a forklift 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.9.4.6 Fire/explosion (battery/electrical fire) associated with a mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.9.4.7 Diesel fuel fire/explosion involving an MSC transporter holding a loaded 
MSC 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 212 April 2005 
6.3.4.9.5 Radiation 
6.3.4.9.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.4.9.5.2 Damage or rupture of cask inerting system leading to a release of MSC 
internal gases 
Exposure of workers to radiation as a result of this potential event will be managed as a normaloperations 
dose by procedures for monitoring radiation doses and assigning work, which ensure 
that workers do not receive excessive radiation doses. Although a rupture leading to a 
radiological release would be an abnormal occurrence, radiation protection programs will ensure 
that such an occurrence would not contribute significantly to the normal operations dose. See 
Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.4.9.5.3 Expansion of gases in the loaded, unsealed MSC, leading to radiological 
release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.4.9.5.4 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.9.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.9.6 Fissile 
6.3.4.9.6.1 Criticality associated with an MSC collision or trolley derailment followed by 
a load tipover or fall and a rearrangement of the MSC internals (before or 
after the outer lid [as applicable] is fastened) 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 213 April 2005 
6.3.4.9.6.2 Criticality associated with a drop or slapdown of a loaded, sealed MSC from 
an overhead crane and a rearrangement of cask internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.4.9.6.3 Criticality associated with an MSC transporter collision while holding a 
loaded, sealed MSC followed by a load tipover or fall and rearrangement of 
the cask internals 
A design requirement is assumed to ensure that the MSC transporter will not derail or allow the 
MSC to fall off the trolley (Assumption 5.1.1.36). Because the transporter remains upright, there 
is no mechanism for reconfiguration of internals and, therefore, no criticality. 
6.3.4.10 WP Handling and Staging Cell, WP Positioning Cells, WP Closure Cells, and 
the WP/trolley decontamination room 
6.3.4.10.1 Collision/Crushing 
6.3.4.10.1.1 Collision involving the trolley holding the loaded, unsealed WP and the 
shield doors between the WP loading/docking ring removal cell and the WP 
handling and staging cell 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.10.1.2 Shield doors between the WP loading/docking ring removal cell and the WP 
handling and staging cell close on the trolley holding the loaded, unsealed 
WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright there is no threat to the integrity of the loaded, unsealed WP. 
6.3.4.10.1.3 Derailment of a trolley holding a loaded, unsealed WP followed by a load 
tipover or fall 
A design requirement is assumed to ensure that a loaded transfer trolley would not derail or 
allow a WP to fall off the trolley (Assumption 5.1.1.36). 
6.3.4.10.1.4 Drop of a loaded, unsealed WP from the WP handling and staging cell 
overhead crane onto the floor during the transfer from the waste transfer 
area pedestal and trolley to a WP positioning cell pedestal and trolley 
This event is included in Section 6.3.1.7.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 214 April 2005 
6.3.4.10.1.5 Drop of a loaded, unsealed WP from the WP handling and staging cell 
overhead crane onto a pedestal on a trolley during the transfer from the 
waste transfer area pedestal and trolley to a WP positioning cell pedestal and 
trolley. 
This event is included in Section 6.3.1.7. 
6.3.4.10.1.6 Drop or collision of a loaded, unsealed WP from the WP handling and 
staging cell overhead crane onto or against a sharp object during the transfer 
from the waste transfer area pedestal and trolley to a WP positioning cell 
pedestal and trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.10.1.7 Slapdown of a loaded, unsealed WP from the WP handling and staging cell 
overhead crane (due to impact with a curb/berm/impact limiter used to 
maintain drop height limits) or pedestal edge during the transfer from the 
waste transfer area pedestal and trolley to a WP positioning cell pedestal and 
trolley 
This event is included in Section 6.3.1.7. 
6.3.4.10.1.8 Drop or collision of equipment (handling equipment, etc.) from the WP 
handling and staging cell overhead crane onto or against a loaded, unsealed 
WP positioned on a pedestal on a trolley 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.4.10.1.9 Collision involving the trolley holding the loaded, unsealed WP and the 
shield doors between WP handling and staging cell and the WP positioning 
cell 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.10.1.10 Shield doors between the WP handling and staging cell and the WP 
positioning cell close on the trolley holding the loaded, unsealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright the unsealed WP will not spill its contents and no event sequence will result. 
6.3.4.10.1.11 Lid drop onto a WP from the lid placement fixture equipment during the 
welding process 
The event is included with the generalized lid-drop event sequence discussed in Section 6.3.1.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 215 April 2005 
6.3.4.10.1.12 Equipment drop onto a WP during the welding process 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.4.10.1.13 Drop or collision of equipment (handling equipment, etc.) from the WP 
handling and staging cell overhead crane onto or against a loaded, sealed WP 
positioned on a pedestal on a trolley 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.4.10.1.14 Collision involving the trolley holding the loaded, sealed WP and the shield 
doors between the WP positioning cell and the WP handling and staging cell 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.10.1.15 Shield doors between the WP positioning cell and the WP handling and 
staging cell close on the trolley holding the loaded, sealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright the WP will not breach no event sequence will result. 
6.3.4.10.1.16 Derailment of a trolley holding a loaded, sealed WP on the rails leading from 
the WP positioning cell, followed by a load tipover or fall 
A design requirement is assumed to ensure that loaded transfer trolleys will not derail or allow 
the WP to fall off the trolley (Assumption 5.1.1.36). Because the trolley remains upright, there is 
no threat to the integrity of the WP. Therefore, no event sequence will occur as a result of this 
potential event. 
6.3.4.10.1.17 Drop of a loaded, sealed WP from the WP handling and staging cell 
overhead crane onto the floor during transfer from the WP positioning cell 
pedestal and trolley to the WP survey station 
This event is included in Section 6.3.1.8. 
6.3.4.10.1.18 Drop or collision of a loaded, sealed WP from the WP handling and staging 
cell overhead crane onto or against a sharp object during transfer from the 
WP positioning cell pedestal and trolley to the WP survey station 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 216 April 2005 
6.3.4.10.1.19 Drop of a loaded, sealed WP from the WP handling and staging cell 
overhead crane onto the floor during transfer from the WP survey station to 
a trolley for transfer to the WP loadout cell or during transfer to a position 
in a vertical orientation in a staging area location in the WP handling and 
staging cell 
Section 6.3.1.8 includes this potential event. 
6.3.4.10.1.20 Drop of a loaded, sealed WP from the WP handling and staging cell 
overhead crane onto a trolley during the transfer from the WP survey station 
to a trolley for transfer to the WP loadout cell. 
Section 6.3.1.8 includes this potential event. 
6.3.4.10.1.21 Drop or collision of a loaded, sealed WP from the WP handling and staging 
cell overhead crane onto or against a sharp object during transfer from the 
WP survey station to a trolley for transfer to the WP loadout cell or during 
transfer to a position in a vertical orientation in a staging area location in the 
WP handling and staging cell 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.10.1.22 Slapdown of a loaded, sealed WP from the WP handling and staging cell 
overhead crane (due to impact with a curb/berm/impact limiter used to 
maintain drop height limits) or trolley edge during transfer from the WP 
survey station to a trolley for transfer to the WP loadout cell or during 
transfer to a position in a vertical orientation in a staging area location in the 
WP handling and staging cell 
Section 6.3.1.8 includes this potential event. The WP is assumed to survive a slapdown without 
breach (Assumption 5.1.3.12). A design requirement is assumed to prevent backward slapdowns 
(Assumption 5.1.1.53). 
6.3.4.10.1.23 Drop or collision of equipment (handling equipment, etc.) from the WP 
handling and staging cell overhead crane onto or against a loaded, sealed WP 
positioned in a vertical position in a staging area location in the WP handling 
and staging cell 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 217 April 2005 
6.3.4.10.1.24 Drop of a loaded, partially sealed WP (WP with a known weld defect) from 
the WP handling and staging cell overhead crane onto the floor during 
transfer from the WP positioning cell pedestal and trolley to a trolley for 
transfer to the DPC cutting/WP dry remediation cell 
Section 6.3.1.9 includes this potential event. 
6.3.4.10.1.25 Drop of a loaded, partially sealed WP (WP with a known weld defect) from 
the WP handling and staging cell overhead crane onto a trolley during the 
transfer from the WP positioning cell pedestal and trolley to a trolley for 
transfer to the DPC cutting/WP dry remediation cell. 
Section 6.3.1.9 includes this potential event. 
6.3.4.10.1.26 Drop or collision of a loaded, partially sealed WP (WP with a known weld 
defect) from the WP handling and staging cell overhead crane onto or 
against a sharp object during transfer from the WP positioning cell pedestal 
and trolley to a trolley for transfer to the DPC cutting/WP dry remediation 
cell 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.10.1.27 Slapdown of a loaded, partially sealed WP (WP with a known weld defect) 
from the WP handling and staging cell overhead crane (due to impact with a 
curb/berm/impact limiter used to maintain drop height limits) or trolley edge 
during the transfer from the WP positioning cell pedestal and trolley to a 
trolley for transfer to the DPC cutting/WP dry remediation cell 
Section 6.3.1.9 includes this potential event. 
6.3.4.10.1.28 Drop of a loaded, sealed WP (WP needing decontamination) from the WP 
handling and staging cell overhead crane onto the floor during transfer from 
the WP survey station to a trolley for transfer to the WP/trolley 
decontamination room 
Section 6.3.1.8 includes this potential event. 
6.3.4.10.1.29 Drop of a loaded, sealed WP (WP needing decontamination) from the WP 
handling and staging cell overhead crane onto a trolley during transfer from 
the WP survey station to a trolley for transfer to the WP/trolley 
decontamination room. 
Section 6.3.1.8 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 218 April 2005 
6.3.4.10.1.30 Drop or collision of a loaded, sealed WP (WP needing decontamination) from 
the WP handling and staging cell overhead crane onto or against a sharp 
object during transfer from the WP survey station to a trolley for transfer to 
the WP/trolley decontamination room 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.10.1.31 Slapdown of a loaded, sealed WP (WP needing decontamination) from the 
WP handling and staging cell overhead crane (due to impact with a 
curb/berm/impact limiter used to maintain drop height limits) or trolley edge 
during the transfer from the WP survey station to a trolley for transfer to the 
WP/trolley decontamination room 
Section 6.3.1.8 includes this potential event. The WP is assumed to survive a slapdown without 
breach (Assumption 5.1.3.12). 
6.3.4.10.1.32 Collision involving the trolley holding the loaded, sealed, contaminated or 
decontaminated WP and the shield doors between the WP handling and 
staging cell and the WP/trolley decontamination room 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.10.1.33 Shield doors between the WP handling and staging cell and the WP/trolley 
decontamination room close on the trolley holding the loaded, sealed, 
contaminated or decontaminated WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). 
6.3.4.10.1.34 Derailment of a trolley holding the loaded, sealed, contaminated or 
decontaminated WP in the WP/trolley decontamination room (or on the rails 
leading to/from this room) followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright there is no 
threat to the integrity of the unsealed WP. 
6.3.4.10.1.35 Drop or collision of equipment (handling equipment, decontamination 
equipment etc.) onto or against a loaded, sealed contaminated or 
decontaminated WP positioned on a trolley in the WP/trolley 
decontamination room 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 219 April 2005 
6.3.4.10.1.36 Drop of a loaded, sealed, decontaminated WP from the WP handling and 
staging cell overhead crane onto the floor during transfer from the trolley 
serving the WP/trolley decontamination room to the trolley to the WP 
loadout cell 
Section 6.3.1.8 includes the potential drop event. Trolley collision is addressed in Section 
6.3.1.22. 
6.3.4.10.1.37 Drop of a loaded, sealed, decontaminated WP from the WP handling and 
staging cell overhead crane onto a trolley during transfer from the trolley 
serving the WP/trolley decontamination room to the trolley to the WP 
loadout cell. 
Section 6.3.1.8 includes this potential event. 
6.3.4.10.1.38 Drop or collision of a loaded, sealed, decontaminated WP from the WP 
handling and staging cell overhead crane onto or against a sharp object 
during transfer from the trolley serving the WP/trolley decontamination 
room to the trolley to the WP loadout cell 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.10.1.39 Slapdown (tipover from an elevated surface) of a loaded, sealed, 
decontaminated WP from the WP handling and staging cell overhead crane 
(due to impact with a curb/berm/impact limiter used to maintain drop height 
limits) or trolley edge during the transfer from the trolley serving the 
WP/trolley decontamination room to the trolley to the WP loadout cell 
Section 6.3.1.8 includes this potential event. The WP is assumed to survive a slapdown without 
breach (Assumption 5.1.3.12). 
6.3.4.10.1.40 Drop or collision of equipment (handling equipment, etc.) from the WP 
handling and staging cell overhead crane onto or against a loaded, sealed or 
partially sealed (with a known weld defect), contaminated or decontaminated 
WP positioned on a pedestal on a trolley, on a trolley without a pedestal, or 
the WP survey station 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 220 April 2005 
6.3.4.10.1.41 Derailment of a trolley holding a loaded, sealed WP on the rails leading from 
the WP handling and staging cell to the WP loadout cell, followed by a load 
tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright there is no 
threat to the integrity of the unsealed WP. 
6.3.4.10.2 Chemical Contamination/Flooding 
6.3.4.10.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.10.2.2 Flooding due to rupture of water line or clogging of drain associated with the 
high pressure water system used for decontamination activities in the 
WP/Trolley decontamination room 
Minor increases in worker doses that may be caused by the spread of contamination due to 
flooding would be managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
See Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.4.10.3 Explosion/Implosion 
6.3.4.10.3.1 Explosion hazard associated with the WP purging and inerting system and 
the ignition of hydrogen that may have accumulated in the WP 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.4.10.3.2 WP decontamination system missile due to a fractured nozzle/valve 
stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.4.10.3.3 WP inerting system (or other pneumatic or pressurized system) missile due 
to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 221 April 2005 
6.3.4.10.4 Fire, Thermal 
6.3.4.10.4.1 Electrical fire associated with handling and other electrically-powered 
equipment in the WP handling and staging cell, the WP positioning cells, and 
the WP closure cells, including the cranes and the welding subsystem in the 
WP closure cells. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.10.4.2 Electrical fire associated with a trolley holding a loaded WP (unsealed or 
sealed) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.10.4.3 Fuel damage by burn-through during welding process/heat damage 
Burn-through of the inner lid is not possible with the gas tungsten arc welding process, which is 
used for the closure welds (BSC 2005 [DIRS 171428], Section 6.6.3.10; BSC 2004 [DIRS 
172428], Section 3). 
6.3.4.10.4.4 Thermal hazard/SNF overheating in a WP during the welding process 
resulting in excessive cladding temperature and possible zircaloy cladding 
(or other cladding) unzipping 
Overheating of the WP contents due to welding is not possible using the gas tungsten arc 
welding process, which is used for the closure welds (BSC 2005 [DIRS 171428], Section 
6.6.3.10; BSC 2004 [DIRS 172428], Section 3). 
6.3.4.10.4.5 Thermal hazard/SNF overheating in a partially sealed WP (WP with weld 
defects) in the WP handling and staging cell, prior to entering WP 
remediation 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.10.4.6 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.10.4.7 Transient combustible fire in the WP handling and staging cells, WP 
positioning cells, WP closure cells, and the WP/trolley decontamination room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 222 April 2005 
6.3.4.10.5 Radiation 
6.3.4.10.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.4.10.5.2 Glovebox leak leads to radiological release of airborne contamination 
Gloveboxes will be inspected for proper functioning and monitored for release of radioactive 
contamination. Therefore, exposure of workers to radiation due to a glovebox leak will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. See Section 
7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.4.10.5.3 Thermal expansion of gases within WP (prior to seal of inner lid) leads to 
radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.4.10.5.4 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.10.5.5 Inadvertent opening of a shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.4.10.5.6 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 223 April 2005 
6.3.4.10.6 Fissile 
6.3.4.10.6.1 Criticality associated with a trolley holding a loaded, sealed or unsealed WP 
derailment followed by a load tipover or fall and a rearrangement of the 
container internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the WP to fall 
off the trolley (Assumption 5.1.1.36). 
6.3.4.10.6.2 Criticality associated with a drop or slapdown of a loaded, unsealed WP and 
a rearrangement of the container contents (including SNF assemblies that 
may move out of the WP) 
Because the WP does not spill its contents (Assumption 5.1.3.11) and moderators are excluded 
from the WP (Assumptions 5.1.3.2 and 5.1.1.21), the unsealed WP will remain subcritical. 
6.3.4.10.6.3 Criticality associated with the drop of heavy equipment onto a loaded, 
unsealed WP and a rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.2). A design 
requirement will also ensure that unsealed WPs cannot sustain a nuclear criticality with 
moderator control in effect (Assumption 5.1.1.21). 
6.3.4.10.6.4 Criticality associated with a drop or slapdown of a loaded, sealed WP and a 
rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). 
6.3.4.11 WP Loadout Cell, WP Transporter Vestibule, Exit Vestibule 
6.3.4.11.1 Collision/Crushing 
6.3.4.11.1.1 Collision involving the trolley holding the loaded, sealed WP and the shield 
doors between the WP handling and staging cell and the WP loadout cell 
Trolley collision is addressed in Section 6.3.1.22.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 224 April 2005 
6.3.4.11.1.2 Shield doors between the WP handling and staging cell and the WP loadout 
cell close on the trolley holding the loaded, sealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright there is no threat to the integrity of the WP. 
6.3.4.11.1.3 Derailment of a trolley in the WP loadout cell holding a loaded, sealed WP 
followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the WP to fall 
off the trolley (Assumption 5.1.1.36). Because the WP remains upright there is no threat to the 
integrity of the WP. 
6.3.4.11.1.4 Drop of a loaded, sealed WP from the WP loadout cell overhead crane onto 
the floor during the transfer from the trolley to the tilting machine 
This potential event is covered by Section 6.3.1.8. 
6.3.4.11.1.5 Drop of a loaded, sealed WP from the WP loadout cell overhead crane back 
onto the trolley during the transfer from the trolley to the tilting machine. 
Section 6.3.1.8 includes this potential event. 
6.3.4.11.1.6 Drop or collision of a loaded, sealed WP from the WP loadout cell overhead 
crane onto or against a sharp object (including the tilting machine) during 
transfer from the trolley to the tilting machine 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.11.1.7 Slapdown (either forward into the WP turntable or backward onto the floor) 
of a loaded, sealed WP engaged in the tilting machine from the WP loadout 
cell overhead crane during the lowering of the WP to the horizontal position 
on the WP pallet previously placed on the WP turntable 
Section 6.3.1.8 includes this potential event. The WP is assumed to survive a slapdown without 
breach (Assumption 5.1.3.12). A design requirement is assumed to prevent backward slapdowns 
(Assumption 5.1.1.53). 
6.3.4.11.1.8 Collision of the tilting machine against a loaded, sealed WP on a pallet on the 
WP turntable 
A design or operational requirement is assumed to ensure that a collision between the tilting 
machine and a WP would not breach the WP (Assumption 5.1.3.10).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 225 April 2005 
6.3.4.11.1.9 Equipment drop or collision (including lifting yokes) onto or against a 
loaded, sealed WP during the process to move the WP from the trolley to the 
tilting machine 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.4.11.1.10 Collision of the WP trunnion collar removal machine and the WP during 
trunnion collar removal 
A design or operational requirement is assumed to ensure that a collision between the trunnion 
collar removal machine and a WP would not breach the WP (Assumption 5.1.3.10). 
6.3.4.11.1.11 Drop of trunnion collar from the 100-ton overhead bridge crane in the WP 
loadout cell onto a WP during trunnion collar removal 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.4.11.1.12 Movement of the WP turntable holding the loaded, sealed WP (positioned on 
the WP pallet) prior to disengagement/removal of the WP trunnion collar 
removal machine 
A design requirement is assumed to ensure that premature actuation of the turntable will not 
cause the WP to breach (Assumption 5.1.1.16). 
6.3.4.11.1.13 Collision of the WP transporter or transporter bedplate with the loaded, 
sealed WP positioned on a pallet on the WP turntable during movement of 
the bedplate under the WP turntable 
Design and operational requirements are assumed to ensure that collision of the WP transporter 
or transporter bedplate with the loaded, sealed WP will not breach the WP or knock it off of the 
turntable (Assumption 5.1.1.39). 
6.3.4.11.1.14 Drop of the loaded, sealed WP (positioned on a pallet) onto the transporter 
bedplate during the lowering of the WP and emplacement pallet from the 
WP turntable to the transporter bedplate positioned under the WP turntable 
Section 6.3.1.8 includes this potential event. 
6.3.4.11.1.15 Collision involving a WP transporter (holding the sealed WP on a pallet) and 
the shield doors between the WP loadout cell and the WP transporter 
vestibule 
A design requirement is assumed to ensure that a collision of the WP transporter could not cause 
a WP breach (Assumptions 5.1.7.3 and 5.1.7.7).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 226 April 2005 
6.3.4.11.1.16 Shield doors between the WP loadout cell and the WP transporter vestibule 
close on the WP transporter (holding the loaded, sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a transporter 
would not overturn the transporter or cause it to drop its load (Assumption 5.1.1.13). Because 
the transporter remains upright there is no threat to the integrity of the WP. 
6.3.4.11.1.17 Collision involving WP transporter (holding the loaded, sealed WP on a 
pallet) and the shield doors between the WP transporter vestibule and the 
exit vestibule 
This potential event is covered by the argument presented in Section 6.3.4.11.1.15. 
6.3.4.11.1.18 Shield doors between the WP transporter vestibule and the exit vestibule 
close on the WP transporter (holding the loaded, sealed WP on a pallet). 
This potential event is covered by the argument presented in Section 6.3.4.11.1.16. 
6.3.4.11.1.19 Collision involving the WP transporter (holding the loaded, sealed WP on a 
pallet) and the doors between the exit vestibule and the ambient air (outside) 
This potential event is covered by the argument presented in Section 6.3.4.11.1.15. 
6.3.4.11.1.20 Doors between the exit vestibule and the ambient air (outside) close on the 
WP transporter (holding the loaded, sealed WP on a pallet) 
This potential event is covered by the analysis in Section 6.3.4.11.1.16. 
6.3.4.11.1.21 Derailment of a WP transporter in the exit vestibule, WP transporter 
vestibule, or WP loadout cell followed by a load tipover or fall 
A design requirement is assumed to ensure that a derailment of the WP transporter could not 
cause a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). 
6.3.4.11.1.22 Drop of a heavy load from the WP loadout crane auxiliary trolley hoist in the 
WP loadout crane park cell onto a loaded, sealed WP 
An operational requirement will ensure that heavy loads that could potentially initiate an event 
sequence if dropped onto a WP will not be lifted over or near a WP, except as needed for transfer 
and closure operations (Assumption 5.1.1.33). 
6.3.4.11.2 Chemical Contamination/Flooding 
6.3.4.11.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because the SNF in this area is contained in a sealed WP (BSC 2005 [DIRS 171428], Section 
6.6.3.11), this potential event will not occur unless an event sequence leads to exposure of SNF
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 227 April 2005 
to air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to air. 
The consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.4.11.3 Explosion/Implosion 
6.3.4.11.3.1 Hydraulic system or other pneumatic or pressurized system missile due to a 
fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.4.11.4 Fire, Thermal 
6.3.4.11.4.1 Electrical fire associated with the WP loadout cell, the WP transporter 
vestibule, or the exit vestibule (including the WP trunnion collar removal 
machine, the tilting machine, and the WP turntable). 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.11.4.2 Electrical fire associated with a trolley holding a sealed WP. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.11.4.3 Electrical fire associated with the WP loadout cell overhead bridge crane. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.11.4.4 Electrical fire associated with equipment on the WP transporter, including 
motors to extend the WP transporter bedplate. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.11.4.5 Electrical fire associated with the WP transport locomotive. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.11.4.6 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 228 April 2005 
6.3.4.11.4.7 Transient combustible fire in the WP loadout cell, the WP transporter 
vestibule, or the exit vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.11.5 Radiation 
6.3.4.11.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.4.11.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.11.5.3 Inadvertent opening of a shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.4.11.5.4 Inadvertent opening of the WP transporter shielded enclosure doors, leading 
to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.4.11.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.11.6 Fissile 
6.3.4.11.6.1 Criticality associated with a trolley holding a loaded, sealed WP derailment 
followed by a load tipover or fall and a rearrangement of the container 
internals 
A design requirement is assumed to ensure that a the trolley will not derail or allow the WP to 
fall off the trolley (Assumptions 5.1.3.1 and 5.1.1.36).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 229 April 2005 
6.3.4.11.6.2 Criticality associated with a drop, slapdown, or collision of a loaded, sealed 
WP and a rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). 
6.3.4.11.6.3 Criticality associated with a WP transporter derailment followed by a load 
tipover or fall and rearrangement of the WP internals 
A design requirement is assumed to ensure that a derailment of the WP transporter would not 
cause a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). Another design requirement is assumed 
to preclude criticality in sealed WPs (Assumption 5.1.3.1). 
6.3.4.12 WP Remediation: DPC Cutting/WP Dry Remediation Cell 
6.3.4.12.1 Collision/Crushing 
6.3.4.12.1.1 Collision involving the trolley holding a loaded, partially sealed WP (with a 
known weld defect) and the shield doors between the WP handling and 
staging cell and the WP/trolley decontamination room or the doors between 
the WP/trolley decontamination room and the DPC cutting/WP dry 
remediation cell 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.12.1.2 Shield doors between the WP handling and staging cell and the WP/trolley 
decontamination room or the doors between the WP/trolley decontamination 
room and the DPC cutting/WP dry remediation cell close on the trolley 
holding a loaded, partially sealed WP (WP with a known weld defect) 
A design requirement is assumed to ensure that closure of the shield doors in the DTF onto a 
transfer trolley would not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). 
Because the trolley remains upright there is no threat to the integrity of the WP, transportation 
cask, MSC, or shuttle cask. Therefore, this potential event will not initiate an event sequence. 
6.3.4.12.1.3 Derailment of a trolley holding a loaded, partially sealed WP (WP with a 
known weld defect) followed by a load tipover or fall, in the DPC cutting/WP 
dry remediation cell 
A design requirement is assumed to ensure that the trolley carrying a WP would not derail or 
allow the WP to fall off the trolley (Assumption 5.1.1.36). Because the transfer trolley remains 
upright there is no threat to the integrity of the cask.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 230 April 2005 
6.3.4.12.1.4 Drop of a loaded, partially sealed WP (WP with a known weld defect) from 
the DPC cutting/WP dry remediation cell overhead crane onto the floor 
during transfer from the trolley to the cutting machine base 
This event is covered in Section 6.3.1.9. 
6.3.4.12.1.5 Drop of a loaded, partially sealed WP (WP with a known weld defect) from 
the DPC cutting/WP dry remediation cell overhead crane onto the cutting 
machine base during transfer from the trolley to the cutting machine base 
The calculation in Section 6.3.1.9 includes this potential event. 
6.3.4.12.1.6 Drop or collision of a loaded, partially sealed WP (WP with a known weld 
defect) from the DPC cutting/WP dry remediation cell overhead crane onto 
or against a sharp object during transfer from the trolley to the cutting 
machine base. 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.12.1.7 Drop or collision of equipment (including a lifting yoke) from the DPC 
cutting/WP dry remediation cell overhead crane onto or against a loaded, 
partially sealed WP (WP with a known weld defect) 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.4.12.1.8 Drop or collision of the WP/canister cutting machine onto or against the 
defective WP during the lowering of the machine for the lid-cutting 
operation 
A design requirement is assumed to ensure that the mass, lift height, and other characteristics of 
the cutting machine are such that the waste-package lid (without credit for the weld) will be able 
to prevent a radiological release should the cutting machine fall onto the WP on approach, during 
cutting, or on withdrawal (Assumption 5.1.5.2). 
6.3.4.12.1.9 Damage to the WP contents (fuel assembly(ies), canisters, etc.) during lidcutting 
operations 
Design requirements for the lid-cutting machine will preclude damage to the contents of the WP 
during the cutting process that results in a radiological release (Assumption 5.1.5.2).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 231 April 2005 
6.3.4.12.1.10 Drop or collision of the WP/canister cutting machine onto or against the 
defective WP during the removal of the machine after the lid-cutting 
operation 
A design requirement is assumed to ensure that the mass, lift height, and other characteristics of 
the cutting machine are such that the waste-package lid (without credit for the weld) will be able 
to prevent a radiological release should the cutting machine fall onto the WP on approach, during 
cutting, or on withdrawal (Assumption 5.1.5.2). 
6.3.4.12.1.11 Drop of a severed lid (outer, middle, or inner) back onto the WP from an 
overhead crane during, or after, the completion, of the WP cutting 
The frequency and consequences of this event are bounded by the Category 2 lid-drop event 
discussed in Section 6.3.1.2. The frequency is bounded because this event only applies to WPs 
in the Remediation Facility, while the bounding event applies to WPs, MSCs, and transportation 
casks in the DTF. The consequences are bounded because WPs have smaller CSNF assembly 
capacities than assumed in the analysis for transportation casks. 
6.3.4.12.1.12 Drop or collision of handling equipment (lid grapple) onto or against the 
unsealed (open), loaded WP 
The lid grapple will not be suspended above the open WP unless the lid is in place or is being 
lifted (Assumption 5.1.1.55). If the lid is in place, operational requirements will prevent 
radiological releases due to this potential event (Assumption 5.1.3.3). If the lid is being lifted, 
the potential event is analyzed as a lid-drop event in Section 6.3.4.12.1.11. 
6.3.4.12.1.13 Drop of an unsealed (open), loaded WP from the overhead crane in the DPC 
cutting/WP dry remediation cell onto the floor during transfer of the WP 
from the cutting machine base to the trolley that travels to the unloading 
port to the waste transfer cell 
The calculation in Section 6.3.1.7 includes this potential event as a component of a generalized 
waste-package drop. 
6.3.4.12.1.14 Drop of an unsealed (open), loaded WP from the overhead crane in the DPC 
cutting/WP dry remediation cell onto the trolley during the transfer of the 
WP from the cutting machine base to the trolley that travels to the unloading 
port to the waste transfer cell 
The calculation in Section 6.3.1.7 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 232 April 2005 
6.3.4.12.1.15 Drop or collision of an unsealed (open), loaded WP from the overhead crane 
in the DPC cutting/WP dry remediation cell onto or against a sharp object 
during transfer of the WP from the cutting machine base to the trolley that 
travels to the unloading port to the waste transfer cell 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.12.1.16 Slapdown of an unsealed (open), loaded WP following a drop from the 
overhead crane in the DPC cutting/WP dry remediation cell onto the edge of 
a pedestal or impact limiter on/near the trolley that travels to the unloading 
port to the waste transfer cell during the lift and transfer to the trolley 
The calculation in Section 6.3.1.7 includes this potential event as a component of a generalized 
waste-package drop. The possibility that the contents of the WP could slide out and be 
sandwiched between the floor of the transfer cell and the lip of the falling WP will be prevented 
by design features (Assumption 5.1.3.11). 
6.3.4.12.1.17 Derailment of a trolley (that travels to the unloading port to the waste 
transfer cell) holding a loaded WP (in an opened state) in the DPC 
cutting/WP dry remediation cell followed by a load tipover or fall 
A design requirement is assumed to ensure that the loaded transfer trolleys will not derail or 
allow the WP to fall off the trolley (Assumption 5.1.1.36). Therefore, this potential event will 
not initiate an event sequence. 
6.3.4.12.1.18 Drop or collision of an SNF assembly from the spent fuel transfer machine 
into or against the WP 
This event is included in Section 6.3.1.10. 
6.3.4.12.1.19 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against another SNF assembly or assemblies in the WP 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop, which is found to be Category 2. 
6.3.4.12.1.20 Impact due to horizontal movement of an SNF assembly by the spent fuel 
transfer machine before the assembly is fully lifted out of the WP 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop or collision.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 233 April 2005 
6.3.4.12.1.21 Drop and slapdown of an SNF assembly from the spent fuel transfer machine 
(due to impact with an edge of the WP, floor edge, WP internal baffle, etc.) 
during the transfer of the SNF assemblies to a WP or staging rack 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop. 
6.3.4.12.1.22 Drop or collision of a naval SNF canister, a DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO from the waste 
transfer cell overhead crane back into or against the WP being unloaded 
The drop event is included in Section 6.3.1.11. Crane-load collisions do not initiate Category 1 
or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.12.1.23 Impact due to horizontal movement of a naval SNF canister, a DOE HLW 
canister, a [standardized] DOE SNF canister, or a DOE SNF MCO with the 
waste transfer cell overhead crane before the canister is completely removed 
from the WP 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.12.1.24 Drop or collision of a DOE HLW canister from the waste transfer cell crane 
back onto or against another DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO in a WP 
The drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.4.12.1.25 Drop or collision of a [standardized] DOE SNF canister from the waste 
transfer cell crane onto or against a DOE HLW canister in the WP 
Dropping a DOE SNF canister onto a DOE HLW canister is rendered Beyond Category 2 by an 
operational requirement not to transfer a DOE SNF canister into the WP if a DOE HLW canister 
is present in the same WP (Assumption 5.1.1.23). Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.12.1.26 Drop or collision of a DOE SNF MCO from the waste transfer cell crane onto 
or against another DOE SNF MCO or a DOE HLW canister in the WP 
Drop of a DOE SNF MCO from above its lift-height limit is Beyond Category 2, as shown in 
Table 31, Event F. If a DOE SNF MCO is dropped onto another MCO within the lift-height 
limit, neither MCO will breach (Assumption 5.1.1.28). Dropping a DOE SNF MCO onto a DOE 
HLW canister is rendered Beyond Category 2 by an operational requirement not to transfer a 
DOE SNF canister into a WP if a DOE HLW canister is present in the same WP (Assumption 
5.1.1.23). Crane-load collisions do not initiate Category 1 or Category 2 event sequences 
(Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 234 April 2005 
6.3.4.12.1.27 Drop and slapdown of a DOE HLW canister, a DOE SNF MCO, a 
[standardized] DOE SNF canister, or a naval SNF canister from the waste 
transfer cell overhead crane (due to impact with an edge of the WP, floor 
edge, WP internal baffle, etc.) during the transfer from the WP to a new WP, 
MSC, or staging rack (if applicable) 
For HLW and naval canisters, this event is covered by Table 31, Event B, where it is shown to be 
Category 2. Drop of a standardized DOE SNF canister or MCO from above its lift-height limit is 
Beyond Category 2, as shown in Table 31, Event F. If a DOE SNF canister is dropped on an 
edge as required for this event, the canister breach is Beyond Category 2 (Assumption 5.1.1.29). 
6.3.4.12.1.28 Drop or collision of handling equipment into or against an opened WP filled 
with SNF assemblies 
Section 6.3.1.18 covers this potential event. 
6.3.4.12.1.29 Drop or collision of handling equipment into or against an opened WP 
loaded with a naval SNF canister, DOE HLW canisters, and/or 
[standardized] DOE SNF canisters, and/or DOE SNF MCOs 
Section 6.3.1.19 covers this potential event. 
6.3.4.12.2 Chemical Contamination/Flooding 
6.3.4.12.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.12.3 Explosion/Implosion 
6.3.4.12.3.1 Explosion hazard associated with the cutting and removal of the WP lid 
system and the ignition of hydrogen that may have accumulated inside the 
WP, including hydrogen removed during the purging process 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.4.12.3.2 Cask/WP purging or sampling system (or other pneumatic or pressurized 
system) missile due to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 235 April 2005 
6.3.4.12.4 Fire, Thermal 
6.3.4.12.4.1 Electrical fire associated with SNF and HLW handling equipment in the 
DPC cutting/WP dry remediation cell (including the overhead cranes, 
manipulators, the chipless cutting equipment, etc.) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.12.4.2 Electrical fire associated with the trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.12.4.3 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.12.4.4 Thermal hazard (from decay heat) associated with vertical orientation of the 
non-inerted opened, loaded WP 
This potential hazard is addressed in Section 6.3.4.12.2.1. 
6.3.4.12.4.5 Transient combustible fire in the DPC cutting/WP dry remediation cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.12.5 Radiation 
6.3.4.12.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.4.12.5.2 Damage or rupture of the WP sampling and purging system, leading to a 
release of WP internal gases and radioactive material 
Like the cask-sampling operation, the WP sampling operation will be conducted so that exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses (BSC 2004 [DIRS 172098], Section 3.2.2.1.1). Although a rupture 
leading to a radiological release would be an abnormal occurrence, radiation protection programs 
will ensure that such an occurrence would not contribute significantly to the normal operations
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 236 April 2005 
dose. See Section 7.4 for a list of potential events and conditions that are treated as normal 
operations. 
6.3.4.12.5.3 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.12.5.4 Thermal expansion of gases or other loss of confinement in an unsealed cask, 
leading to radiological release 
Exposure of workers to radiation due to this potential event will be managed as a normaloperations 
dose by procedures for monitoring radiation doses and assigning work, which ensure 
that workers do not receive excessive radiation doses. See Section 7.4 for a list of potential 
events and conditions that are treated as normal operations. 
6.3.4.12.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.12.6 Fissile 
6.3.4.12.6.1 Criticality associated with a trolley (holding a partially sealed WP requiring 
remediation) derailment followed by a load tipover or fall and a 
rearrangement of the container internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36), thereby making this event Beyond Category 2. 
6.3.4.12.6.2 Criticality associated with a drop of an SNF assembly from the waste 
transfer cell spent fuel transfer machine back into the WP being unloaded 
and a rearrangement of the WP internals 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumption 5.1.3.2). 
6.3.4.12.6.3 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine back into a WP being unloaded and a rearrangement of the 
fuel rods that comprise the assembly due to impact 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumption 5.1.3.2).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 237 April 2005 
6.3.4.12.6.4 Criticality associated with a drop or slapdown of a WP from the DPC 
cutting/WP dry remediation cell overhead crane and a rearrangement of the 
container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). 
6.3.4.12.6.5 Criticality associated with a drop or slapdown of a naval SNF canister, a 
[standardized] DOE SNF canister, a DOE SNF MCO, or a DOE HLW 
canister from the waste transfer cell overhead crane during WP unloading 
Design calculations and the resulting design requirements will ensure criticality safety for DOE 
SNF canisters involved in this event (Assumption 5.1.1.3). The potential for criticality for naval 
canisters is addressed in Attachment I, where it is demonstrated that a criticality associated with 
the drop of a naval canister is Beyond Category 2. There is no potential for criticality of HLW 
canisters (Assumption 5.2.1.19). 
6.3.4.12.6.6 Criticality associated with a trolley (holding an unsealed, open WP) 
derailment followed by a load tipover or fall and a rearrangement of the 
container internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to tip over or fall (Assumption 5.1.1.36). 
6.3.4.12.6.7 Criticality associated with the drop of heavy equipment onto an unsealed, 
open WP and a rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). A design 
requirement will also ensure that unsealed WPs cannot sustain a nuclear criticality with 
moderator control in effect (Assumption 5.1.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 238 April 2005 
6.3.4.13 Dry Remediation: Cask Docking/Dry Remediation Room, Tool Spare Transfer 
Room, DPC Cutting/WP Dry Remediation Cell 
6.3.4.13.1 Collision/Crushing 
6.3.4.13.1.1 Collision involving the trolley holding the cask or MSC requiring 
remediation and the shield doors between the cask and MSC docking room 
and the cask/MSC turntable room, the cask/MSC turntable room and the 
cask preparation room, the cask preparation room and the DPC 
preparation/cask dry remediation room, the DPC preparation/cask dry 
remediation room and the DPC docking room, the DPC docking room and 
the cask docking/dry remediation room, or the cask docking/dry remediation 
room and the tool spare transfer room 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.13.1.2 Shield doors between the cask and MSC docking room and the cask/MSC 
turntable room, the cask/MSC turntable room and the cask preparation 
room, the cask preparation room and the DPC preparation/cask dry 
remediation room, the DPC preparation/cask dry remediation room and the 
DPC docking room, the DPC docking room and the cask docking/dry 
remediation room, or the cask docking/dry remediation room and the tool 
spare transfer room close on the trolley holding the cask or MSC requiring 
remediation 
A design requirement is assumed to ensure that closure of the shield doors onto a transfer trolley 
would not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the 
trolley remains upright there is no threat to the integrity of the WP. Therefore, this potential 
event will not initiate an event sequence. 
6.3.4.13.1.3 Derailment of a trolley in the cask and MSC docking room, the cask/MSC 
turntable room, the cask preparation room, the DPC preparation/cask dry 
remediation room, the DPC docking room, the cask docking/dry remediation 
room, or the tool spare transfer room while holding a cask or MSC, followed 
by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36), thereby making this event Beyond Category 2. 
Because the WP remains upright there is no threat to the integrity of the unsealed WP. 
6.3.4.13.1.4 Drop or collision of tools or equipment onto or against a cask or MSC 
requiring remediation 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 239 April 2005 
6.3.4.13.1.5 Collision involving an access platform or a mobile elevated platform (if 
required) and a cask or MSC requiring remediation 
Operational requirements are assumed to ensure that the access platform will not be operated in a 
manner that could breach a transportation cask or MSC (Assumption 5.1.1.41). 
6.3.4.13.1.6 Collision of a trolley holding the cask or MSC requiring remediation with 
another trolley holding a cask or MSC on the turntable in the DPC docking 
room or on the tracks leading to the cask docking/dry remediation room or 
tool spare transfer room 
Trolley collision is addressed in Section 6.3.1.22. 
6.3.4.13.1.7 Drop or collision of a docking port (mobile slab) onto or against a cask or 
MSC 
A design requirement is assumed to ensure that this potential event will not initiate an event 
sequence (Assumption 5.1.1.17). 
6.3.4.13.1.8 Drop or collision of a docking port plug onto or against a cask lid or MSC lid 
(with outer lid removed [if applicable] and inner lid unbolted but in place) 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37). 
6.3.4.13.1.9 Drop of an inner lid on a cask or MSC (with outer lid removed [if 
applicable]) 
This potential event is included in Section 6.3.1.2. 
6.3.4.13.1.10 Drop or collision of a grapple or other handling equipment into or against an 
open cask or MSC loaded with commercial SNF assemblies, a DPC, a DOE 
HLW canister, a DOE SNF MCO, or a [standardized] DOE SNF canister 
This potential event is treated as two different events, depending on the contents of the cask. In 
each case, it is assumed that no more than 10 percent of the SNF and HLW to be emplaced is 
handled in the dry remediation areas (Assumption 5.2.3.1). For CSNF assemblies, the analysis 
of Section 6.3.1.18 applies, and the event sequence is Category 2. The amount of material at risk 
is one CSNF assembly. 
For the cases in which the cask contains a DOE HLW canister, a DOE SNF MCO, a DOE SNF 
canister, or a naval canister, the analysis in Section 6.3.1.19 applies. One Category 2 event 
sequence emerges and it results in the breach of one HLW canister.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 240 April 2005 
6.3.4.13.1.11 Drop or collision of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane back into or against a cask or MSC being unloaded 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop. 
6.3.4.13.1.12 Drop or collision of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane onto or against another SNF assembly in a cask or 
MSC 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop. 
6.3.4.13.1.13 Impact due to horizontal movement of an SNF assembly by the DPC 
cutting/WP dry remediation cell crane before the assembly is completely 
removed from the cask or MSC 
The calculation in Section 6.3.1.10 includes this potential event as a component of the 
generalized assembly collision in the dry remediation areas. 
6.3.4.13.1.14 Drop of an SNF assembly from the DPC cutting/WP dry remediation cell 
crane onto the DPC cutting/WP dry remediation cell floor 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop. 
6.3.4.13.1.15 Collision involving an SNF assembly suspended from the DPC cutting/WP 
dry remediation cell crane with equipment located in the DPC cutting/WP 
dry remediation cell or on the cell floor (such as lid lifting equipment) 
The calculation in Section 6.3.1.10 includes this potential event as a component of the 
generalized assembly collision in the dry remediation areas. 
6.3.4.13.1.16 Drop or collision of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane onto or against a sharp object 
The calculation in Section 6.3.1.10 includes this potential event because the assembly is assumed 
to breach. 
6.3.4.13.1.17 Drop or collision of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane into or against an empty basket located on a trolley in 
the DPC cutting/WP dry remediation cell 
The calculation in Section 6.3.1.10 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 241 April 2005 
6.3.4.13.1.18 Drop and slapdown of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane (due to impact with an edge of the cask, MSC, basket, 
floor edge, basket internal baffle, etc.) during the transfer from the cask or 
MSC to a basket on a trolley in the DPC cutting/WP dry remediation cell 
The calculation in Section 6.3.1.10 includes this potential event. 
6.3.4.13.1.19 Drop or collision of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane onto or against one or more SNF assemblies in a 
basket on a trolley in the DPC cutting/WP dry remediation cell 
The calculation in Section 6.3.1.10 includes this potential event. 
6.3.4.13.1.20 Drop or collision of a DPC, a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO from the DPC cutting/WP dry 
remediation cell crane back into or against the cask or MSC being unloaded, 
as applicable 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.21 Drop or collision of a DPC, a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO from the DPC cutting/WP dry 
remediation cell crane back into or against a DPC, a DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO in the cask or MSC, 
as applicable 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.22 Impact due to horizontal movement of a DPC, a DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO with the DPC 
cutting/WP dry remediation cell crane before the canister is completely 
removed from the cask or MSC, as applicable 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.4.13.1.23 Drop and slapdown of a DPC, a DOE HLW canister, a DOE SNF MCO, or a 
[standardized] DOE SNF canister from the DPC cutting/WP dry remediation 
cell crane (due to impact with an edge of the cask, MSC, floor edge, basket 
internal baffle, etc.) during the transfer from the cask or MSC (as applicable) 
to a basket on a trolley in the DPC cutting/WP dry remediation cell 
This potential event is included in Section 6.3.1.11.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 242 April 2005 
6.3.4.13.1.24 Drop or collision of a DPC, a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO from the DPC cutting/WP dry 
remediation cell crane onto or against a sharp object. 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.13.1.25 Collision involving a DPC, a DOE HLW canister, a [standardized] DOE SNF 
canister, or a DOE SNF MCO suspended from the DPC cutting/WP dry 
remediation cell crane with equipment located in the DPC cutting/WP dry 
remediation cell or on the cell floor 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.26 Drop of a DPC, a DOE HLW canister, a [standardized] DOE SNF canister, 
or a DOE SNF MCO from the DPC cutting/WP dry remediation cell crane 
onto the DPC cutting/WP dry remediation cell floor 
This potential event is included in Section 6.3.1.11. 
6.3.4.13.1.27 Drop or collision of a DPC, a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO from the DPC cutting/WP dry 
remediation cell crane into or against an empty basket on a trolley in the 
DPC cutting/WP dry remediation cell 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.28 Drop or collision of a DOE HLW canister from the DPC cutting/WP dry 
remediation cell crane onto or against another DOE HLW canister or 
[standardized] DOE SNF canister or a DOE SNF MCO in a basket, as 
applicable, on a trolley in the DPC cutting/WP dry remediation cell 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.29 Drop or collision of a [standardized] DOE SNF canister from the DPC 
cutting/WP dry remediation cell crane onto or against a DOE HLW canister, 
as applicable, in a basket on a trolley in the DPC cutting/WP dry remediation 
cell 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 243 April 2005 
6.3.4.13.1.30 Drop or collision of a DOE SNF MCO from the DPC cutting/WP dry 
remediation cell crane onto or against another DOE SNF MCO or a DOE 
HLW canister, as applicable, in a basket on a trolley in the DPC cutting/WP 
dry remediation cell 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.31 Drop or collision of handling equipment from the DPC cutting/WP dry 
remediation cell crane into or against a basket on a trolley in the DPC 
cutting/WP dry remediation cell filled with SNF assemblies 
This event is included in Section 6.3.1.18. 
6.3.4.13.1.32 Drop or collision of handling equipment from the DPC cutting/WP dry 
remediation cell crane into or against a basket on a trolley in the DPC 
cutting/WP dry remediation cell loaded with DOE HLW canisters, and/or a 
[standardized] DOE SNF canister, and/or DOE SNF MCOs, as applicable 
This event sequence is bounded in frequency by the analysis in Section 6.3.1.6 because only a 
fraction of canisters are handled in the dry remediation areas. Therefore, the event is Category 2. 
The amount of material at risk is one HLW canister. 
6.3.4.13.1.33 Drop or collision of handling equipment from the DPC cutting/WP dry 
remediation cell crane into or against a basket on a trolley in the DPC 
cutting/WP dry remediation cell loaded with a DPC (if not emptied) 
This event is included in Section 6.3.1.18. 
6.3.4.13.1.34 Derailment of a trolley (that travels to the unloading port to the waste 
transfer cell) holding a loaded basket containing SNF assemblies in the DPC 
cutting/WP dry remediation cell, followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the loaded 
basket to fall off the trolley (Assumption 5.1.1.36), thereby rendering this event Beyond 
Category 2. Because the WP remains upright there is no threat to the integrity of the loaded 
basket. 
6.3.4.13.1.35 Derailment of a trolley (that travels to the unloading port to the waste 
transfer cell) holding a loaded basket containing a DPC (if not emptied), or a 
combination of DOE HLW canisters, [standardized] DOE SNF canisters, or 
DOE SNF MCOs, as applicable, in the DPC cutting/WP dry remediation cell, 
followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the loaded 
basket to fall off the trolley (Assumption 5.1.1.36), thereby rendering this event Beyond 
Category 2. Because the WP remains upright there is no threat to the integrity of the loaded 
basket.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 244 April 2005 
6.3.4.13.1.36 Drop or collision of an SNF assembly from the spent fuel transfer machine 
back into or against the basket on a trolley that is being unloaded 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop, which is found to be Category 2. 
6.3.4.13.1.37 Drop or collision of an SNF assembly from the spent fuel transfer machine 
back onto or against another SNF assembly or assemblies in the basket on a 
trolley 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop, which is found to be Category 2. 
6.3.4.13.1.38 Impact due to horizontal movement of an SNF assembly by the spent fuel 
transfer machine before the assembly is fully lifted out of the basket on a 
trolley 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop, which is found to be Category 2. 
6.3.4.13.1.39 Drop and slapdown of an SNF assembly from the spent fuel transfer machine 
(due to impact with an edge of the basket, the floor edge, a basket internal 
baffle, etc.) during the SNF transfer from the basket on the trolley to a WP 
or staging rack 
The calculation in Section 6.3.1.10 includes this potential event as a component of a generalized 
assembly drop. 
6.3.4.13.1.40 Drop or collision of a DPC (if not emptied), a DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO, as applicable, from 
the waste transfer cell overhead crane back into or against the basket on a 
trolley being unloaded 
The calculation in Section 6.3.1.11 includes the potential drop event. Crane-load collisions do 
not initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.41 Impact due to horizontal movement of a DPC (if not emptied), a DOE HLW 
canister, a [standardized] DOE SNF canister, or DOE SNF MCO, as 
applicable, with the waste transfer cell overhead crane before the canister is 
completely removed from the basket on a trolley 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 245 April 2005 
6.3.4.13.1.42 Drop or collision of a DOE HLW canister from the waste transfer cell crane 
back onto or against another DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO, as applicable, in the basket on a trolley 
This potential event is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 
1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.43 Drop or collision of a [standardized] DOE SNF canister from the waste 
transfer cell crane onto or against a DOE HLW canister in the basket on a 
trolley 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.44 Drop or collision of a DOE SNF MCO from the waste transfer cell crane onto 
or against another DOE SNF MCO or a DOE HLW canister, as applicable, 
in the basket on a trolley 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.13.1.45 Drop and slapdown of a DOE HLW canister, a DOE SNF MCO, or a 
[standardized] DOE SNF canister, as applicable, from the waste transfer cell 
overhead crane (due to impact with an edge of the basket, floor edge, basket 
internal baffle, etc.) during the transfer from the basket on a trolley to a new 
WP or staging rack (if applicable) 
This potential event is included in Section 6.3.1.11. 
6.3.4.13.1.46 Drop or collision of handling equipment from the spent fuel transfer machine 
into or against a basket on a trolley filled with SNF assemblies 
This event is included in Section 6.3.1.18. 
6.3.4.13.1.47 Drop or collision of handling equipment from the waste transfer cell 
overhead crane into or against a basket on a trolley loaded with DOE HLW 
canisters, and/or [standardized] DOE SNF canisters, and/or DOE SNF 
MCOs, as applicable 
This event is bounded by Section 6.3.1.6. The expected number of events is bounded because 
only a fraction of the DOE canisters will be handled in the Remediation Facility. The potential 
consequences are the same.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 246 April 2005 
6.3.4.13.2 Chemical Contamination/Flooding 
6.3.4.13.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
High temperatures could lead to oxidation of the CSNF matrix whenever CSNF assemblies with 
failed cladding are exposed to air. Oxidation of failed CSNF assemblies is expected as a part of 
normal operations wherever CSNF assemblies are exposed to air. Resulting exposure of workers 
to radiation will be managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
See Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.4.13.3 Explosion/Implosion 
6.3.4.13.3.1 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.4.13.3.2 Explosion hazard associated with the cask and MSC sampling and purging 
system and the ignition of hydrogen that may have accumulated in the cask 
or MSC 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.4.13.4 Fire, Thermal 
6.3.4.13.4.1 Electrical fire associated with tools or SNF and HLW handling equipment in 
the cask docking/ dry remediation room, the tool spare transfer room, or the 
DPC cutting/WP dry remediation cell (including the overhead cranes, 
manipulators, turntable, etc.) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.13.4.2 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.13.4.3 Thermal hazard (from decay heat) associated with vertical orientation of the 
cask, MSC, or basket 
This hazard is addressed in Section 6.3.4.13.2.1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 247 April 2005 
6.3.4.13.4.4 Transient combustible fire in the cask docking/dry remediation room, the 
tool spare transfer room, or the DPC cutting/WP dry remediation cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.13.4.5 Electrical fire associated with the trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.13.4.6 Fire/explosion (battery/electrical fire) associated with a mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.13.5 Radiation 
6.3.4.13.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.4.13.5.2 Damage or rupture of the cask and MSC sampling and purging system, 
leading to a release of canister internal gases and radioactive material 
The sampling operation will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. (BSC 2004 
[DIRS 172098], Section 3.2.2.1.1). Although a rupture leading to a radiological release would 
be an abnormal occurrence, radiation protection programs will ensure that such an occurrence 
would not contribute significantly to the normal operations dose. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.13.5.3 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.13.5.4 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Exposure of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 248 April 2005 
6.3.4.13.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.4.13.6 Fissile 
6.3.4.13.6.1 Criticality associated with a trolley derailment (holding a cask or MSC 
requiring remediation) followed by a load tipover or fall and a 
rearrangement of the container internals 
A design requirement is assumed to ensure that the trolley will not derail or allow a cask to fall 
off the trolley (Assumption 5.1.1.36), thereby making this event Beyond Category 2. Because 
the trolley remains upright, there is no mechanism for reconfiguration of internals and, therefore, 
no criticality. 
6.3.4.13.6.2 Criticality associated with a drop of an SNF assembly from the DPC 
cutting/WP dry remediation cell crane back into the cask or MSC being 
unloaded or drop into a basket on a trolley being unloaded and a 
rearrangement of the cask, MSC, or basket internals 
A design requirement will ensure that a drop of a CSNF assembly back into the cask or MSC or 
a drop into a basket (allowing for rearrangement of container internals and optimal moderator 
intrusion) cannot lead to a nuclear criticality (Assumption 5.1.1.4). 
6.3.4.13.6.3 Criticality associated with a drop or slapdown of a [standardized] DOE SNF 
canister, a DOE SNF MCO, or a DOE HLW canister from DPC cutting/WP 
dry remediation cell crane during cask or MSC unloading or basket on a 
trolley loading (as applicable) 
Design calculations and the resulting design requirements will ensure criticality safety for DOE 
SNF canisters involved in this event (Assumption 5.1.1.3). There is no potential for criticality of 
HLW canisters (Assumption 5.2.1.19). 
6.3.4.13.6.4 Criticality associated with a trolley (holding a basket containing SNF 
assemblies, a naval SNF canister, or various combinations of [standardized] 
DOE SNF canisters, DOE SNF MCOs, or DOE HLW canisters) derailment 
followed by a load tipover or fall and a rearrangement of the basket contents 
A design requirement is assumed to ensure that the trolley will not derail or allow a basket to fall 
off the trolley (Assumption 5.1.1.36). Because the basket remains upright, there is no 
mechanism for reconfiguration of internals and, therefore, no criticality.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 249 April 2005 
6.3.4.13.6.5 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine back into the basket on a trolley being unloaded and a 
rearrangement of the basket contents 
Design requirements will ensure that dropping a CSNF assembly back into the basket (allowing 
for rearrangement of container internals) cannot lead to a nuclear criticality (Assumption 
5.1.1.4). 
6.3.4.13.6.6 Criticality associated with a drop of an SNF assembly from the DPC 
cutting/WP dry remediation cell crane back into the cask or MSC being 
unloaded or onto the DPC cutting/WP dry remediation cell floor and a 
rearrangement of the fuel rods that comprise the assembly due to impact 
A design requirement will ensure that drops and collisions involving a CSNF assembly (allowing 
for rearrangement of fuel rods and without credit for burnup) cannot lead to a nuclear criticality 
(Section 4.1.10 and Assumption 5.1.1.4). 
6.3.4.13.6.7 Criticality associated with a drop or slapdown of a [standardized] DOE SNF 
canister, a DOE SNF MCO, or a DOE HLW canister from waste transfer cell 
crane during the unloading of the basket on a trolley (as applicable) 
Design calculations and the resulting design requirements will ensure criticality safety for DOE 
SNF canisters involved in this event (Assumption 5.1.1.3). There is no potential for criticality of 
HLW canisters (Assumption 5.2.1.19). 
6.3.4.13.6.8 Criticality associated with the drop of heavy equipment (lifting fixture, etc.) 
onto a basket on a trolley and a rearrangement of the basket contents 
An operational requirement will prohibit lifting heavy equipment high enough above a basket on 
a trolley to pose a criticality concern (Assumption 5.1.5.8). 
6.3.4.14 Wet Remediation: Cask Wet Remediation/Laydown Area, Cask Wet 
Remediation Entrance Vestibule 
6.3.4.14.1 Collision/Crushing 
6.3.4.14.1.1 Collision involving the trolley (holding the cask or MSC to be remediated) 
and the door to the cask wet remediation entrance vestibule, the shield doors 
between the cask wet remediation entrance vestibule and the cask wet 
remediation/laydown area, or the shield doors between the DPC docking 
room and the cask wet remediation/laydown area 
Trolley collision is addressed in Section 6.3.1.22.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 250 April 2005 
6.3.4.14.1.2 Doors to the cask wet remediation entrance vestibule, the shield doors 
between the cask wet remediation entrance vestibule and the cask wet 
remediation/laydown area, or the shield doors between the DPC docking 
room and the cask wet remediation/laydown area close on the trolley 
(holding the cask or MSC to be remediated) 
A design requirement is assumed to ensure that closure of the shield doors in the Remediation 
Facility onto a transfer trolley would not overturn the trolley or cause it to drop its load 
(Assumption 5.1.1.13). Because the trolley remains upright there is no threat to the integrity of 
the cask. 
6.3.4.14.1.3 Derailment of a trolley in the cask wet remediation/laydown area while 
holding a cask or MSC to be remediated, followed by a load tipover or fall. 
A design requirement is assumed to ensure that the cask-transfer trolley would not derail or 
allow the cask to fall off the trolley (Assumption 5.1.1.36). Because the transfer trolley remains 
upright there is no threat to the integrity of the cask. 
6.3.4.14.1.4 SRTC derailment involving a loaded cask (with or without impact limiters 
installed) or MSC 
A design requirement is assumed to ensure that the SRTC will not derail and the cask or MSC 
will not fall off the SRTC (Assumption 5.1.1.35). Because the SRTC remains upright there is no 
threat to the integrity of the cask. 
6.3.4.14.1.5 Collision of an SRTC carrying a loaded cask (with or without impact limiters 
installed) or MSC with the cask wet remediation entrance vestibule doors or 
the cask wet remediation/laydown area shield doors 
A design or operational requirement is assumed to ensure that a collision of the SRTC with the 
doors will not overturn the SRTC or cause it to drop its load (Assumption 5.1.1.38). Because the 
SRTC remains upright there is no threat to the integrity of the MSC. 
6.3.4.14.1.6 Cask wet remediation entrance vestibule doors or the cask wet 
remediation/laydown area shield doors close on an SRTC carrying a loaded 
cask (with or without impact limiters installed) or MSC 
A design requirement is assumed to ensure that closure of the shield doors onto an SRTC would 
not overturn the SRTC or cause it to drop its load (Assumption 5.1.1.13). 
6.3.4.14.1.7 Collision of a mobile elevated platform with a loaded cask or MSC during 
removal of a personnel barriers and impact limiters (if applicable) or during 
survey activities 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach a loaded cask or MSC (Assumption 5.1.1.41).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 251 April 2005 
6.3.4.14.1.8 Drop or collision of personnel barriers or impact limiters from the cask wet 
remediation/laydown area crane onto or against a loaded cask (if applicable) 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.4.14.1.9 Slapdown of a loaded cask onto an SRTC during upending of the loaded cask 
to the vertical orientation 
This potential event is covered by Section 6.3.1.1. 
6.3.4.14.1.10 Drop and slapdown of a loaded MSC onto an SRTC or the floor during the 
lift of the loaded MSC off of the SRTC 
This potential event is covered by Section 6.3.1.1. 
6.3.4.14.1.11 Drop of a loaded cask or MSC from the overhead bridge crane onto the floor 
during transfer from the trolley or SRTC to the cask decontamination 
pit/cask prep pit 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.12 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
onto or against a sharp object during transfer from the trolley or SRTC to 
the cask decontamination pit/cask prep pit 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.14.1.13 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
into or against the cask decontamination pit/cask prep pit during transfer 
from the trolley or SRTC to the cask decontamination pit/cask prep pit 
The potential drop event is included as part of Section 6.3.1.13. Crane-load collisions do not 
initiate Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.14.1.14 Tipover or slapdown of a loaded cask or MSC from the overhead bridge 
crane into the cask decontamination pit/cask prep pit or onto the floor due to 
contact with the pit ledge or access platform during transfer from the trolley 
or SRTC to the cask decontamination pit/cask prep pit. 
This event is included as part of Section 6.3.1.13.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 252 April 2005 
6.3.4.14.1.15 Drop or collision of handling equipment (including the cask lifting yoke, cask 
skirt, cask skirt lifting beam, and cask immersion rod) onto or against the 
cask or MSC before or after transfer of the cask to the cask decontamination 
pit/cask prep pit. 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.4.14.1.16 Collision involving an access platform and a cask or MSC in the cask 
decontamination pit/cask prep pit. 
Operational requirements are assumed to ensure that the access platform will not be operated in a 
manner that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.4.14.1.17 Drop or collision of the cask lid bolt detorque machine or other cask prep 
equipment onto or against a loaded cask or MSC or cask or MSC inner lid 
(including a lid-lifting fixture, cask gas sample/purge system equipment, cask 
cool-down equipment, etc.). 
An operational requirement is assumed to ensure that the detorque machine or other equipment 
will not be handled in a manner that could breach the transportation cask or MSC or the 
associated inner lid (without credit for the bolts) if the machine or other equipment is dropped 
(Assumptions 5.1.5.6 and 5.1.1.30). 
6.3.4.14.1.18 Drop of a cask or MSC outer lid from the overhead crane onto the cask or 
MSC 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event for CSNF assembly casks that was discussed in Section 6.3.1.2. The frequency is bounded 
because this event only applies to transportation casks and MSCs in the remediation pool, while 
the bounding event applies to WPs, MSCs, and transportation casks in the other areas. The 
consequences are bounded because the amount of material at risk (74 BWR or 36 PWR 
assemblies) is the same in each instance but the pool would mitigate the release for this event. 
6.3.4.14.1.19 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
back into or against a pit during transfer from the cask decontamination 
pit/cask prep pit into the pool 
The potential drop event is covered in Section 6.3.1.13. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.14.1.20 Drop of a loaded cask or MSC from the overhead bridge crane onto the cell 
floor during transfer from the cask decontamination pit/cask prep pit into 
the pool 
This event is included as part of Section 6.3.1.13.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 253 April 2005 
6.3.4.14.1.21 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
onto or against a sharp object during transfer from the cask 
decontamination pit/cask prep pit into the pool 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.14.1.22 Drop of a loaded cask or MSC from the overhead bridge crane onto the pool 
floor during transfer from the cask decontamination pit/cask prep pit into 
the pool. 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.23 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
onto or against an empty cask or MSC already in the pool during transfer 
from the cask decontamination pit/cask prep pit into the pool 
The potential drop event is covered in Section 6.3.1.13. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.14.1.24 Tipover or slapdown of a loaded cask or MSC from the overhead bridge 
crane (due to impact with the pool edge or ledge/wall in the pool) into the 
pool during transfer from the cask decontamination pit/cask prep pit into the 
pool 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.25 Drop or collision of handling equipment (or other equipment, including an 
immersion rod) onto or against the lid of a loaded cask or MSC positioned in 
the pool prior to, or after, the cask or MSC lid removal or installation 
process, respectively. 
This potential event involves a drop of equipment, either before lid removal or after lid 
installation. Thus, the lid is always in place at the time of this potential event. Operational 
requirements will prevent initiation of an event sequence for this potential event (Assumption 
5.1.1.30). 
6.3.4.14.1.26 Collision involving a lid suspended in the pool from the fuel handling 
machine removing (or installing) the cask or MSC lid during the lid removal 
(or installation) process in the pool 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event discussed in Section 6.3.1.2. The frequency is bounded because this event only applies to 
transportation casks and MSCs in the remediation pool, while the bounding event applies to 
WPs, MSCs, and transportation casks in the DTF. The consequences are bounded because the 
amount of material at risk is the same in each instance but the pool would mitigate the release for 
this event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 254 April 2005 
6.3.4.14.1.27 Drop of a cask or MSC inner lid onto or into a loaded cask or MSC from the 
fuel handling machine during the lid removal (or installation) process in the 
pool 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event discussed in Section 6.3.1.2. The frequency is bounded because this event only applies to 
transportation casks and MSCs in the remediation pool, while the bounding event applies to 
WPs, MSCs, and transportation casks in the DTF. The consequences are bounded because the 
amount of material at risk is the same in each instance but the pool would mitigate the release for 
this event. 
6.3.4.14.1.28 Drop or collision of an empty cask or MSC from overhead bridge crane onto 
or against the cask or MSC already in the pool (to be unloaded) during the 
lowering of the empty cask or MSC into the pool 
The potential drop event is addressed in Section 6.3.1.14. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.14.1.29 Drop or collision of the cask or MSC lid from the empty cask or MSC onto or 
against the unsealed (open) cask to be unloaded 
This event is included in Section 6.3.4.14.1.18. 
6.3.4.14.1.30 Drop or collision of an empty SNF basket onto or against the cask to be 
unloaded 
It is assumed that an empty basket dropped or collided against a cask will not cause a 
radiological release (Assumption 5.1.5.7). 
6.3.4.14.1.31 Drop or collision of an empty or full canister for damaged SNF onto or 
against the cask being unloaded 
This event is included as part of Section 6.3.1.15. 
6.3.4.14.1.32 Drop or collision of an empty or full canister for damaged SNF onto or 
against the empty or full SNF basket being loaded 
This event is included as part of Section 6.3.1.15. 
6.3.4.14.1.33 Drop of an SNF assembly onto the pool floor while suspended from the fuel 
handling machine during transfer from the cask to the SNF basket or to the 
empty cask or MSC in the pool 
This event is included as part of Section 6.3.1.16.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 255 April 2005 
6.3.4.14.1.34 Drop or collision of an SNF assembly onto or against a sharp object while 
suspended from the fuel handling machine during transfer from the cask to 
the SNF basket or to the empty cask or MSC in the pool 
This event is included as part of Section 6.3.1.16. The assembly is assumed to breach. 
6.3.4.14.1.35 Drop or collision of an SNF assembly back into or against the cask or MSC 
being unloaded while suspended from the fuel handling machine during 
transfer from the cask to the SNF basket or to the empty cask or MSC in the 
pool 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.36 Drop or collision of an SNF assembly onto or against another assembly or 
assemblies in the cask or MSC while suspended from the fuel handling 
machine during transfer from the cask to the SNF basket or to the empty 
cask or MSC in the pool. 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.37 Impact due to horizontal movement of an SNF assembly by the fuel handling 
machine before the assembly is fully lifted out of the cask or MSC 
This event is a collision of the assembly with the basket structure within the cask. Drops and 
collisions occur at approximately the same rate per transfer (Assumptions 5.1.1.7 and 5.1.1.8). 
Therefore, the finding of Category 2 in Section 6.3.1.16 applies to this collision event as well. In 
this event, only one assembly is affected. 
6.3.4.14.1.38 Drop or collision of an SNF assembly into or against the empty SNF basket 
in the pool while suspended from the fuel handling machine during transfer 
from the cask or MSC to an empty location in the SNF basket 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.39 Drop or collision of an SNF assembly onto or against another fuel assembly 
or assemblies in the SNF basket in the pool while suspended from the fuel 
handling machine during transfer from the cask or MSC to an empty 
location in the SNF basket 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.40 Collision of the fuel handling machine basket grapple with a filled SNF 
basket during the closing (or opening) of the SNF basket 
It is assumed that a basket grapple collided against a cask will not damage fuel in the cask and 
will not cause a radiological release (Assumption 5.1.5.7).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 256 April 2005 
6.3.4.14.1.41 Drop of a filled SNF basket from the fuel handling machine onto the pool 
floor during transfer of the filled SNF basket to (or from) the pool area 
basket storage rack 
This event is included as part of Section 6.3.1.17. 
6.3.4.14.1.42 Drop or collision of a filled SNF basket from the fuel handling machine onto 
or against a sharp object during transfer of the filled SNF basket to (or from) 
the pool area basket storage rack 
This event is included as part of Section 6.3.1.17. The assembly is assumed to breach. 
6.3.4.14.1.43 Drop or collision of a filled SNF basket from the fuel handling machine onto, 
into, or against the cask or MSC being unloaded or loaded (containing SNF) 
during transfer of the filled SNF basket to or from the pool area basket 
storage rack. 
This event is included as part of Section 6.3.1.17. 
6.3.4.14.1.44 Drop or collision of a filled SNF basket from the fuel handling machine onto 
or against an empty basket storage rack location during transfer of the filled 
SNF basket to (or from) the pool area basket storage rack 
This event is included as part of Section 6.3.1.17. 
6.3.4.14.1.45 Drop or collision of a filled SNF basket from the fuel handling machine onto 
or against a filled basket storage rack location (onto another filled SNF 
basket) during transfer of the filled SNF basket to (or from) the pool area 
basket storage rack 
This event is included as part of Section 6.3.1.17. 
6.3.4.14.1.46 Drop or collision of handling equipment from the fuel handling machine onto 
or against an SNF assembly or assemblies in the SNF basket (before or after 
transfer to pool area basket storage rack) 
This event is included in Section 6.3.1.12. 
6.3.4.14.1.47 Drop of an SNF assembly onto the pool floor while suspended from the fuel 
handling machine during transfer to an empty cask or MSC from the SNF 
basket 
This event is included as part of Section 6.3.1.16.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 257 April 2005 
6.3.4.14.1.48 Drop or collision of an SNF assembly onto or against a sharp object while 
suspended from the fuel handling machine during transfer to an empty cask 
or MSC from the SNF basket 
This event is included as part of Section 6.3.1.16. The assembly is assumed to breach. 
6.3.4.14.1.49 Impact due to horizontal movement of an SNF assembly by the fuel handling 
machine before the assembly is fully lifted out of the SNF basket 
This event is a collision of the assembly with the basket structure within the cask. Drops and 
collisions occur at approximately the same rate per transfer (Assumptions 5.1.1.7 and 5.1.1.8). 
Therefore, the finding of Category 2 in Section 6.3.1.16 applies to this collision event as well. In 
this event, only one assembly is affected. 
6.3.4.14.1.50 Drop or collision of an SNF assembly back into or against the SNF basket 
being unloaded in the pool while suspended from the fuel handling machine 
during transfer to an empty cask or MSC 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.51 Drop or collision of an SNF assembly onto or against another assembly or 
assemblies in the SNF basket in the pool while suspended from the fuel 
handling machine during transfer to an empty cask or MSC 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.52 Drop or collision of an SNF assembly into or against an empty MSC in the 
pool while suspended from the fuel handling machine during transfer to an 
empty location in a cask or MSC from the SNF basket 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.53 Drop or collision of an SNF assembly onto or against another fuel assembly 
or assemblies inside the MSC in the pool while suspended from the fuel 
handling machine during transfer to an empty location in a cask or MSC 
from the SNF basket 
This event is included as part of Section 6.3.1.16. 
6.3.4.14.1.54 Drop or collision of an empty SNF basket onto or against a filled cask or 
MSC during movement of the empty SNF basket (after closure of the basket) 
back to the pool area basket storage rack 
It is assumed that an empty basket dropped or collided against a cask will not cause a 
radiological release (Assumption 5.1.5.7).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 258 April 2005 
6.3.4.14.1.55 Drop or collision of handling equipment or a lid (or other equipment), either 
from the overhead bridge crane, maintenance crane, or from the fuel 
handling machine, onto or against an SNF assembly or assemblies in an open 
unsealed cask or MSC positioned at the bottom of the pool 
Drops or collisions of handing equipment are covered in Section 6.3.1.12. Lid drops are 
discussed in Section 6.3.4.14.1.18. 
6.3.4.14.1.56 Drop or collision of handling equipment (or other equipment) from the 
overhead bridge crane onto or against a loaded cask or MSC positioned at 
the bottom of the pool after the lid has been installed, prior to removal from 
the pool 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.4.14.1.57 Drop of a loaded cask or MSC from the overhead bridge crane onto the pool 
floor during transfer from the pool to the cask decontamination pit/cask prep 
pit 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.58 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
onto or against a sharp object in the pool during transfer out of the pool to 
the cask decontamination pit/cask prep pit 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.14.1.59 Tipover or slapdown of a loaded cask or MSC into the cask decontamination 
pit/cask prep pit from overhead bridge crane due to impact with the pit edge 
or access platform in the pit during transfer from the pool to the cask 
decontamination pit/cask prep pit 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.60 Tipover or slapdown of a loaded cask or MSC into the pool from the 
overhead bridge crane due to impact with the pool edge or ledge/wall in the 
pool during transfer from the pool to the cask decontamination pit/cask prep 
pit. 
This event is included as part of Section 6.3.1.13.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 259 April 2005 
6.3.4.14.1.61 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
into or against the cask decontamination pit/cask prep pit during transfer 
from the pool to the cask decontamination pit/cask prep pit 
The potential drop event is covered in Section 6.3.1.13. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.14.1.62 Drop of a loaded cask or MSC from the overhead bridge crane onto the wet 
remediation area floor during transfer from the pool to the cask 
decontamination pit/cask prep pit or from the cask decontamination pit/cask 
prep pit to a trolley 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.63 Drop of a loaded cask or MSC from the overhead bridge crane onto the 
trolley during the transfer from the cask decontamination pit/cask prep pit 
to a trolley. 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.64 Drop or collision of a loaded cask or MSC from the overhead bridge crane 
onto or against a sharp object in the cask wet remediation/laydown area 
during transfer from the pool to the cask decontamination pit/cask prep pit 
or from the cask decontamination pit/cask prep pit to a trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.14.1.65 Slapdown of a loaded cask or MSC following a drop from the overhead 
bridge crane (due to contact with the edge of a trolley or trolley pedestal) 
during the lift from the cask decontamination pit/cask prep pit to the trolley 
This event is included as part of Section 6.3.1.13. 
6.3.4.14.1.66 Drop or collision of an unloaded cask from the overhead bridge crane onto 
or against a loaded cask or MSC in the pool during transfer of the empty 
cask from the pool 
The potential drop event is addressed in Section 6.3.1.14. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.4.14.1.67 Collision involving an access platform and a loaded cask or MSC in the cask 
decontamination pit/cask prep pit 
Operational requirements are assumed to ensure that the access platform will not be operated in a 
manner that could breach a transportation cask or MSC (Assumption 5.1.1.41).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 260 April 2005 
6.3.4.14.1.68 Drop of a cask or MSC outer lid from the overhead crane onto the loaded 
cask or MSC 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event discussed in Section 6.3.1.2. The frequency is bounded because this event only applies to 
transportation casks in the remediation pool, while the bounding event applies to WPs, MSCs, 
and transportation casks in the DTF. The consequences are bounded because the amount of 
material at risk is the same in each instance but the pool would mitigate the release for this event. 
6.3.4.14.1.69 Drop or collision of equipment (including the lifting yoke, cask skirt, cask 
skirt lifting beam, etc.), the lid bolt torque machine, dry vacuum equipment, 
leak test equipment, flushing equipment, etc., or other cask preparation or 
decontamination equipment, onto or against a loaded cask or MSC or cask 
or MSC inner lid 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.4.14.1.70 Drop or collision of handling equipment (including the cask lifting yoke) onto 
or against a cask or MSC before or after transfer of the loaded, sealed cask 
or MSC to the trolley. 
Operational requirements are assumed to ensure that a drop of handling equipment onto a 
transportation cask without impact limiters or an MSC would not breach the cask (Assumption 
5.1.1.30). 
6.3.4.14.1.71 Derailment of a trolley holding a loaded, sealed cask or MSC followed by a 
load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the cask or 
MSC to fall off the trolley (Assumption 5.1.1.36). Because the cask or MSC remains upright 
there is no threat to the integrity of the cask or MSC. 
6.3.4.14.1.72 Collision of a trolley holding a loaded, sealed remediated cask or MSC with 
shield doors separating the cask wet remediation/laydown area and DPC 
docking room 
Collisions involving trolleys are covered in Section 6.3.1.22. 
6.3.4.14.1.73 Shield doors separating the cask wet remediation/laydown area and the DPC 
docking room close on a trolley holding a loaded, sealed, remediated cask or 
MSC 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 261 April 2005 
6.3.4.14.2 Chemical Contamination/Flooding 
6.3.4.14.2.1 Uncontrolled pool water draindown resulting in flooding (including a 
draindown resulting from a puncture of the pool liner due to a cask drop) 
Design and operational requirements are assumed to ensure that loss of pool water will not 
initiate an event sequence in the pool (Assumptions 5.1.2.5 and 5.1.2.6). Initiation of an event 
sequence due to flooding initiated in the pool and spreading to moderator control areas of the 
facility is rendered Beyond Category 2 by a design requirement that mandates flood controls 
(Assumption 5.1.1.21). 
6.3.4.14.2.2 Uncontrolled pool water overfill resulting in flooding (including an overfill 
resulting from cask or MSC placement into an overfilled pool, malfunction of 
make-up water equipment, etc.) 
A design requirement is assumed to ensure that flooding of areas of the facility where 
moderators are excluded due to the presence of fissile material is precluded by passive design 
features such as drains, flood control channels, curbs, elevated processing areas, and walls 
(Assumption 5.1.1.21). Therefore, flooding due to uncontrolled filling or draining of the pool 
will not initiate an event sequence as a result of a flood initiated in the pool spreading to other 
areas of the facility. 
6.3.4.14.2.3 Cask decontamination pit/cask prep pit flooding due to pool overfill, 
flooding, pool equipment malfunction, cask preparation system (cask 
cooling) equipment malfunction, etc 
The only hazard due to flooding involves the possibility of criticality due to moderator intrusion. 
Flooding the pit will not lead to a nuclear criticality because transportation casks (Section 4.2.1) 
and MSCs (Assumption 5.1.1.4) must be subcritical even with the most reactive credible 
configuration of the fissile material and moderation to the most reactive credible extent. 
6.3.4.14.2.4 Uncontrolled water spill from the cask decontamination system or the cask 
preparation system (cask cooling) in the cask wet remediation/laydown area 
The only hazard due to flooding involves the possibility of criticality due to moderator intrusion. 
Flooding the wet remediation/laydown area will not lead to a nuclear criticality because 
transportation casks (Section 4.2.1) and MSCs (Assumption 5.1.1.4) must be subcritical even 
with the most reactive credible configuration of the fissile material and moderation to the most 
reactive credible extent. 
6.3.4.14.2.5 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
High temperatures could lead to oxidation of the CSNF matrix whenever CSNF with failed 
cladding is exposed to air. Oxidation of failed CSNF assemblies is expected as a part of normal 
operations wherever CSNF assemblies are exposed to air. Resulting exposure of workers to 
radiation will be managed as a normal-operations dose by procedures for monitoring radiation
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 262 April 2005 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
See Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.4.14.3 Explosion/Implosion 
6.3.4.14.3.1 Hydrogen explosion involving batteries on a trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a breach in casks or WPs (Assumption 5.1.1.51). 
6.3.4.14.3.2 Explosion hazard associated with the cask sampling and purging system and 
the ignition of hydrogen that may have accumulated in the cask or MSC 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.4.14.3.3 Cask cooling system (nitrogen, air, etc.) or MSC drying system (or other 
pneumatic or pressurized system) missile due to fractured nozzle/valve 
stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.4.14.3.4 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by transportation casks or MSCs while in the presence of batteries for 
heavy equipment. The magnitude of a potential hydrogen explosion involving batteries for 
heavy equipment will be insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.4.14.3.5 Steam explosion or cask overpressurization due to insufficient cooling of a 
cask or MSC contents prior to insertion of the cask or MSC into the pool 
The quenching operation will take into account the need to sufficiently cool the cask before 
insertion into the pool (Assumption 5.1.5.10). 
6.3.4.14.4 Fire, Thermal 
6.3.4.14.4.1 Electrical fires associated with the vacuum drier, pool water makeup 
equipment, or other pool-related equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 263 April 2005 
6.3.4.14.4.2 Electrical fire associated with SNF and HLW handling equipment or other 
associated equipment in the cask wet remediation/laydown area and cask wet 
remediation entrance vestibule (including the cask lid bolt detorque device, 
the turntable, manipulators, overhead bridge cranes, the fuel handling 
machine, etc.) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.14.4.3 Fire/explosion (battery/electrical fire) associated with the trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.14.4.4 Fire/explosion (battery/electrical fire) associated with the mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.14.4.5 Diesel fuel fire/explosion involving an SRTC tractor pushing an SRTC 
holding a transportation cask or MSC into the cask wet remediation 
entrance vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.14.4.6 Overheating of SNF due to loss of pool water, including events that could 
lead to such a loss, including the breakdown of the pool water cooling system, 
resulting in excessive cladding temperature and possible zircaloy cladding 
(or other cladding) unzipping 
Design and operational requirements are assumed to ensure that loss of pool water will not 
initiate an event sequence in the pool (Assumptions 5.1.2.5 and 5.1.2.6). 
6.3.4.14.4.7 Rapid cooling of SNF assemblies, leading to excessive thermal stresses in the 
SNF cladding 
Quenching of CSNF assemblies is a part of normal operations. The normal operation will take 
into account the thermal stresses induced to prevent initiation of an event sequence (Assumption 
5.1.5.10). 
6.3.4.14.4.8 Damage to SNF due to insufficient cooling of a cask prior to lowering it into 
the pool, resulting in a thermal shock that damages the SNF cladding 
Quenching of casks is a part of normal operations. The normal operation will take into account 
the thermal stresses induced to prevent initiation of an event sequence (Assumption 5.1.5.10).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 264 April 2005 
6.3.4.14.4.9 Intact or non-intact SNF overheating due to a loss of cooling resulting in 
excessive temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.14.4.10 Thermal hazard (from decay heat) associated with vertical orientation of a 
cask or MSC 
This hazard is addressed in Section 6.3.4.14.2.5. 
6.3.4.14.4.11 Transient combustible fire in the cask wet remediation/laydown area or the 
cask wet remediation entrance vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.14.5 Radiation 
6.3.4.14.5.1 Damage or rupture of the cask sampling and purging system, leading to a 
release of internal gases and radioactive material 
The sampling operation will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. (BSC 2004 
[DIRS 172098], Section 3.2.2.1.1). Although a rupture leading to a radiological release would 
be an abnormal occurrence, radiation protection programs will ensure that such an occurrence 
would not contribute significantly to the normal operations dose. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.14.5.2 Uncontrolled pool water draindown/fill or leak of pool cooling or water 
treatment system resulting in flooding and radioactive contamination of 
adjoining areas 
Design and operational requirements will ensure that a loss of pool water will not initiate an 
event sequence in the pool (Assumptions 5.1.2.5 and 5.1.2.6). Water quality will be kept within 
prescribed limits to ensure radiological doses as low as reasonably achievable in the areas around 
the pools; and the disposition of leaking water will be controlled (BSC 2004 [DIRS 167860], 
Section 7). Pool operations will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. See Section 
7.4 for a list of potential events and conditions that are treated as normal operations.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 265 April 2005 
6.3.4.14.5.3 Increased radiation levels in the pool cell due to low pool water level 
uncovering of SNF assemblies (either in an opened cask or MSC or in the 
SNF basket staging rack) 
Design and operational requirements are assumed to ensure that pool water level is maintained 
(Assumptions 5.1.2.5 and 5.1.2.6). 
6.3.4.14.5.4 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.4.14.5.5 Loss of confinement zones due to a ventilation system malfunction or other 
breach of a confinement barrier leading to a release of radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.14.5.6 Insufficient cooling of a cask or loss of the cask cooling system prior to 
lowering of a cask into the pool, leading to a release of radiologically 
contaminated steam or gases 
Pool operations will be conducted so that exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.4.14.5.7 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.4.14.5.8 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 266 April 2005 
6.3.4.14.6 Fissile 
6.3.4.14.6.1 Criticality associated with a derailment of a trolley moving a loaded cask or 
MSC followed by a load tipover or fall and a rearrangement of the container 
internals. 
A design requirement is assumed to ensure that the trolley will not derail or allow a loaded cask 
or MSC to fall off the trolley (Assumption 5.1.1.36). 
6.3.4.14.6.2 Criticality associated with a derailment of a SRTC holding a loaded cask or 
MSC followed by a load tipover or fall and a rearrangement of the container 
internals 
A design requirement is assumed to ensure that a SRTC will not derail or allow a cask or an 
MSC to fall off the SRTC (Assumption 5.1.1.35). 
6.3.4.14.6.3 Criticality associated with a drop, slapdown, or collision of a cask or an MSC 
(when handled with an overhead crane) and a rearrangement of the 
container internals. 
This event, which involves a single transportation cask or MSC, will not lead to a criticality 
because design requirements and waste acceptance criteria will ensure criticality safety in 
transportation casks and MSCs (Assumption 5.1.1.4). 
6.3.4.14.6.4 Criticality associated with a drop of an SNF assembly while unloading a 
transportation cask, loading cask or MSC, or filling or emptying an SNF 
basket in the pool, and a rearrangement of SNF in the cask, MSC, or basket. 
A design requirement is assumed to ensure criticality safety in the baskets and baskets in the 
storage rack (Assumption 5.1.5.9). Transportation casks and MSCs will remain subcritical even 
with configuration of the fissile material and optimal moderation (Assumption 5.1.1.4). 
6.3.4.14.6.5 Criticality associated with a drop of an SNF assembly from the fuel handling 
machine (in the pool) and a rearrangement of the fuel rods that comprise the 
assembly due to impact 
Drops and collisions involving the drop of a single CSNF assembly cannot lead to a nuclear 
criticality (Section 4.1.10). 
6.3.4.14.6.6 Criticality associated with a misload of a cask or MSC in the pool 
A design requirement is assumed to ensure that MSCs remain subcritical with optimum 
moderation and most reactive waste forms (Assumption 5.1.1.4). Therefore, misload of an MSC 
cannot cause a nuclear criticality.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 267 April 2005 
6.3.4.14.6.7 Criticality associated with a misload of an SNF baskets or SNF baskets in the 
basket storage rack 
A design requirement is assumed to preclude this potential event (Assumption 5.1.5.9). 
6.3.4.14.6.8 Criticality associated with the drop of a spent fuel assembly basket holding 
several SNF assemblies in the pool (including a drop onto another basket) 
and a rearrangement of the contents of the basket or baskets 
A design requirement is assumed to ensure that the baskets are designed to have sufficient 
nuclear criticality controls to remain subcritical under the expected range of conditions resulting 
from handling incidents, in and out of staging racks (Assumption 5.1.5.9). 
6.3.4.14.6.9 Criticality associated with the drop of heavy equipment onto a loaded fuel 
basket (either a single basket or several baskets in a basket storage rack) and 
a rearrangement of the contents of the basket or baskets 
A design requirement is assumed to ensure that the baskets are designed to have sufficient 
nuclear criticality controls to remain subcritical under the expected range of conditions resulting 
from handling incidents, in and out of staging racks (Assumption 5.1.5.9). Therefore, equipment 
drop with consequent deformation of the fuel assemblies in the storage rack cannot lead to a 
criticality. 
6.3.4.14.6.10 Criticality associated with the drop of heavy equipment onto a loaded cask or 
MSC and a rearrangement of the container internals (either in or out of the 
pool) 
This event will not lead to a criticality because transportation casks and MSCs must be 
subcritical (Section 5.1.1.4) even with the most reactive credible configuration of the fissile 
material and moderation to the most reactive credible extent. 
6.3.4.15 DPC Cutting: DPC Preparation/Cask Dry Remediation Room, DPC Docking 
Room, DPC Cutting/WP Dry Remediation Cell 
6.3.4.15.1 Collision/Crushing 
6.3.4.15.1.1 Collision involving the trolley holding the cask containing the loaded DPC 
and the shield doors between the cask preparation room and the DPC 
preparation/cask dry remediation room 
Collisions involving trolleys are covered in Section 6.3.1.22.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 268 April 2005 
6.3.4.15.1.2 Shield doors between the cask preparation room and the DPC 
preparation/cask dry remediation room close on the trolley holding the cask 
containing the loaded DPC 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). 
6.3.4.15.1.3 Derailment of a trolley in the DPC preparation/cask dry remediation room 
or DPC docking room (including derailment due to turntable malfunction or 
operational error) while holding a cask containing a loaded DPC followed by 
a load tipover or fall 
A design requirement is assumed to ensure that the transfer trolley carrying a loaded SNF DPC 
will not derail or allow the DPC to fall off the trolley (Assumption 5.1.1.36), thereby making this 
event Beyond Category 2. Because the trolley remains upright there is no threat to the integrity 
of the DPC. 
6.3.4.15.1.4 Drop or collision of a docking ring (or tools, or equipment) onto or against 
the cask containing the DPC. 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.4.15.1.5 Collision involving the docking ring station or other access platforms and a 
cask containing a loaded DPC in the DPC preparation/cask dry remediation 
room 
Operational requirements are assumed to ensure that the docking ring station or other access 
platforms will be not be operated in a manner that could breach or overturn a cask (Assumption 
5.1.1.41). 
6.3.4.15.1.6 Collision involving a trolley holding the cask containing the loaded DPC and 
the shield doors between DPC preparation/cask dry remediation room and 
the DPC docking room 
Collisions involving trolleys are covered in Section 6.3.1.22. 
6.3.4.15.1.7 Shield doors between the DPC preparation/cask dry remediation room and 
the DPC docking room close on a trolley holding the cask containing the 
loaded DPC 
A design requirement is assumed to ensure that closure of the shield doors onto a transportation 
cask transfer trolley would not overturn the trolley or cause it to drop its load (Assumption 
5.1.1.13). Because the trolley remains upright there is no threat to the integrity of the cask.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 269 April 2005 
6.3.4.15.1.8 Derailment of a trolley holding the cask containing the loaded DPC on the 
turntable in the DPC docking room followed by a load tipover or fall 
A design requirement is assumed to ensure that the cask-transfer trolley carrying a DPC in the 
DTF will not derail or allow the DPC to fall off the trolley (Assumption 5.1.1.36). Because the 
transfer trolley remains upright there is no threat to the integrity of the cask. 
6.3.4.15.1.9 Collision of a trolley holding the cask containing the loaded DPC with 
another trolley holding a cask on the turntable in the DPC docking room 
Collisions involving trolleys are covered in Section 6.3.1.22. 
6.3.4.15.1.10 Drop or collision of a docking port (mobile slab) onto or against a cask 
containing the loaded DPC 
A design requirement is assumed to ensure that this potential event will not initiate an event 
sequence (Assumption 5.1.1.17). 
6.3.4.15.1.11 Drop or collision of a docking port plug onto or against the lid of a cask 
containing the loaded DPC (with outer lid removed [if applicable] and inner 
lid unbolted but in place) 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37). 
6.3.4.15.1.12 Drop of an inner lid on a cask containing the loaded DPC (with outer lid 
removed [if applicable]) 
This potential event is included in Section 6.3.1.2. 
6.3.4.15.1.13 Drop or collision of DPC handling device or tools or equipment onto or 
against the DPC during the drilling/installation of the DPC handling device. 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.4.15.1.14 Drop or collision of a loaded DPC from the DPC Cutting/WP Dry 
Remediation Cell overhead crane through the unload port back into or 
against the cask being unloaded during the DPC transfer from the cask to 
the DPC cutting/WP dry remediation cell cutting machine base 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 270 April 2005 
6.3.4.15.1.15 Drop of a loaded DPC from the DPC Cutting/WP Dry Remediation Cell 
overhead crane onto the DPC cutting/WP dry remediation cell floor during 
DPC transfer from the cask to the DPC cutting/WP dry remediation cell 
cutting machine base 
This potential event is included in Section 6.3.1.5. 
6.3.4.15.1.16 Drop of a loaded DPC from the DPC Cutting/WP Dry Remediation Cell 
overhead crane onto the cutting machine base during DPC transfer from the 
cask to the DPC cutting/WP dry remediation cell cutting machine base 
This potential event is included in Section 6.3.1.5. 
6.3.4.15.1.17 Drop or collision of a loaded DPC from the DPC Cutting/WP Dry 
Remediation Cell overhead crane onto or against a sharp object during DPC 
transfer from the cask to the DPC cutting/WP dry remediation cell cutting 
machine base 
DPCs and the assemblies within are assumed to breach when dropped. The potential drop event 
is included in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or Category 2 
event sequences (Section 6.3.1.21). 
6.3.4.15.1.18 Drop or collision of the lid-cutting machine onto or against the DPC during 
the lowering of the machine for the lid-cutting operation. 
A design requirement is assumed to ensure that the mass, lift height, and other characteristics of 
the lid-cutting machine are such that the DPC will be able to prevent a radiological release 
should the lid-cutting machine fall onto the DPC on approach or during lid-cutting operations 
(Assumption 5.1.5.3). 
6.3.4.15.1.19 Damage to one or more fuel assemblies during lid-cutting operations or the 
DPC drainpipe cutting operation. 
The design of the canister-cutting machine will preclude a radiological release as a result of 
damage to CSNF assemblies during the cutting process (Assumption 5.1.5.4). 
6.3.4.15.1.20 Drop or collision of the DPC cutting machine onto or against the open 
(lidless) DPC during the removal of the machine after the lid-cutting 
operation 
An operational requirement is assumed to ensure that this potential event does not initiate an 
event sequence (Assumption 5.1.5.5). 
6.3.4.15.1.21 Drop or collision of the severed lid back onto or against the open DPC from 
the ceiling-mounted manipulator or overhead crane after the completion of 
the DPC lid-cutting 
Section 6.3.1.20 covers this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 271 April 2005 
6.3.4.15.1.22 Drop or collision of handling equipment (lid grapple, etc.) onto or against the 
unsealed (open), loaded DPC 
The lid grapple will not be suspended above the open DPC unless the lid is in place or is being 
lifted (Assumption 5.1.1.55). If the lid is in place, a design requirement ensures that drop of 
handling equipment onto a DPC with its severed lid in place would not initiate an event sequence 
(Assumption 5.1.1.32). If the lid is being lifted, the potential event is analyzed as a lid-drop 
event in Section 6.3.4.15.1.21. 
6.3.4.15.1.23 Drop of an unsealed (open), loaded DPC from the overhead crane in the DPC 
cutting/WP dry remediation cell onto the floor during transfer of the DPC 
from the DPC cutting machine base to the trolley that travels to the 
unloading port to the waste transfer cell 
This event is included in the analysis of Section 6.3.1.5. 
6.3.4.15.1.24 Drop of an unsealed (open), loaded DPC from the overhead crane in the DPC 
cutting/WP dry remediation cell onto the trolley during the transfer of the 
DPC from the DPC cutting machine base to the trolley that travels to the 
unloading port to the waste transfer cell 
This event is included in the analysis of Section 6.3.1.5. 
6.3.4.15.1.25 Drop or collision of an unsealed (open), loaded DPC from the overhead crane 
in the DPC cutting/WP dry remediation cell onto or against a sharp object 
during transfer of the DPC from the DPC cutting machine base to the trolley 
that travels to the unloading port to the waste transfer cell 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.4.15.1.26 Slapdown of an unsealed (open), loaded DPC following a drop from the 
overhead crane in the DPC cutting/WP dry remediation cell onto the edge of 
a trolley that travels to the unloading port to the waste transfer cell during 
the lift and transfer to the trolley 
This event is included in the analysis of Section 6.3.1.5. 
6.3.4.15.1.27 Derailment of a trolley (that travels to the unloading port to the waste 
transfer cell) holding a loaded DPC (in an unsealed, opened state) in the DPC 
cutting/WP dry remediation cell, followed by a load tipover or fall 
A design requirement is assumed to ensure that a derailment of a WP/DPC trolley carrying a 
WP/DPC in the DTF would not cause the trolley to overturn or the DPC to fall off the trolley 
(Assumption 5.1.1.36).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 272 April 2005 
6.3.4.15.1.28 Drop or collision of an SNF assembly from the spent fuel transfer machine 
back into or against the DPC being unloaded 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.15.1.29 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against another SNF assembly or assemblies in the DPC being 
unloaded 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.15.1.30 Impact due to horizontal movement of an SNF assembly by the spent fuel 
transfer machine before the assembly is fully lifted out of the DPC. 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.15.1.31 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against a sharp object (other than another SNF assembly). 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). 
6.3.4.15.1.32 Drop and slapdown of an SNF assembly from the spent fuel transfer machine 
(due to impact with an edge of the DPC, the floor edge, a DPC internal baffle, 
etc.) during the SNF transfer from the DPC to a WP or staging rack 
The calculation in Section 6.3.1.3 includes this potential event. 
6.3.4.15.2 Chemical Contamination/Flooding 
6.3.4.15.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
High temperatures could lead to oxidation of the CSNF matrix whenever CSNF with failed 
cladding is exposed to air. Oxidation of failed CSNF assemblies is expected as a part of normal 
operations wherever CSNF assemblies are exposed to air. Resulting exposure of workers to 
radiation will be managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
See Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.4.15.3 Explosion/Implosion 
6.3.4.15.3.1 Hydrogen explosion involving batteries on a cask-handling trolley 
The waste is protected by transportation casks or MSCs while in the presence of batteries for 
heavy equipment. The magnitude of a potential hydrogen explosion involving batteries for 
heavy equipment will be insufficient to cause a radiological release (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 273 April 2005 
6.3.4.15.3.2 Explosion hazard associated with the sampling and purging system or the 
cutting and removal of the DPC enclosure lid system and the ignition of 
hydrogen that may have accumulated in the canister 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.4.15.3.3 DPC sampling and purging system (or other pneumatic or pressurized 
system) missile due to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.4.15.4 Fire, Thermal 
6.3.4.15.4.1 Electrical fire associated with SNF handling equipment in the DPC 
preparation/dry remediation room, DPC docking room, the waste transfer 
cell, or the DPC cutting/WP dry remediation cell (including the overhead 
cranes, manipulators, the chipless cutting equipment, etc.) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.15.4.2 Fire/explosion (battery/electrical fire) associated with the cask-handling 
trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.15.4.3 Electrical fire associated with the trolley in the DPC cutting/WP dry 
remediation cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.15.4.4 Intact or non-intact SNF overheating due to a loss of cooling resulting in 
excessive temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stress 
This potential event is discussed in Section 6.3.1.26. 
6.3.4.15.4.5 Thermal hazard (from decay heat) associated with vertical orientation of the 
cask holding the DPC 
This hazard is addressed in Section 6.3.4.15.2.1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 274 April 2005 
6.3.4.15.4.6 Transient combustible fire in the DPC preparation/dry remediation room, 
DPC docking room, the waste transfer cell, or the DPC cutting/WP dry 
remediation cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.4.15.5 Radiation 
6.3.4.15.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.4.15.5.2 Damage or rupture of the DPC sampling and purging system, leading to a 
release of canister internal gases and radioactive material 
The sampling operation will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. (BSC 2004 
[DIRS 172098], Section 3.2.2.1.1). Although a rupture leading to a radiological release would 
be an off-normal occurrence, any release and related dose would be managed as part of routine 
radiation protection operations. See Section 7.4 for a list of potential events and conditions that 
are treated as normal operations. 
6.3.4.15.5.3 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.4.15.5.4 Thermal expansion of gases or other loss of confinement in an unsealed cask, 
leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.4.15.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 275 April 2005 
6.3.4.15.6 Fissile 
6.3.4.15.6.1 Criticality associated with a derailment of a trolley moving a cask holding a 
sealed, loaded DPC and a rearrangement of the DPC contents followed by a 
load tipover or fall 
A criticality in the DTF is not credible because design requirements and waste acceptance 
criteria will ensure criticality safety in DPCs (Assumption 5.1.1.4) 
6.3.4.15.6.2 Criticality associated with a drop or slapdown of a sealed, loaded DPC from 
the DPC Cutting/WP Dry Remediation Cell overhead crane and a 
rearrangement of the DPC contents 
The event discussed in Section 6.3.5.5.6.2 covers this event. 
6.3.4.15.6.3 Criticality associated with a drop or slapdown of an unsealed (open) loaded, 
or sealed (unopened) loaded DPC from DPC cutting area overhead crane 
and a rearrangement of the DPC contents 
A design requirement will ensure that DPCs are designed such that handling impacts (allowing 
for rearrangement of container internals) cannot lead to a nuclear criticality with moderator 
control in effect (Assumption 5.1.1.4). 
6.3.4.15.6.4 Criticality associated with a derailment of a trolley moving an unsealed 
(open) loaded DPC followed by a load tipover or fall and a rearrangement of 
the DPC contents 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
DPC to fall off the trolley (Assumption 5.1.1.36), thereby making this event Beyond Category 2. 
Because the WP remains upright, there is no mechanism for reconfiguration of internals and, 
therefore, no criticality. 
6.3.4.15.6.5 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine back into the DPC being unloaded and a rearrangement of 
the canister internals 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumption 5.1.1.4). 
6.3.4.15.6.6 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine and a rearrangement of the fuel rods that comprise the 
assembly due to impact 
Drops and collisions involving the drop of a single CSNF assembly cannot lead to a nuclear 
criticality (Section 4.1.10).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 276 April 2005 
6.3.4.15.6.7 Criticality associated with the drop of heavy equipment onto an unsealed 
(open) loaded, or sealed (unopened) loaded DPC and a rearrangement of the 
container internals 
A design requirement will ensure that DPCs are designed such that handling impacts (allowing 
for rearrangement of container internals) cannot lead to a nuclear criticality with moderator 
control in effect (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 277 April 2005 
6.3.5 FHF 
A description of the operations in this area and a listing of the hazards and potential events are 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.4). 
6.3.5.1 FHF Entrance Vestibule (Cask and MSC Receipt) 
6.3.5.1.1 Collision/Crushing 
6.3.5.1.1.1 Railcar derailment, overturning, or collision involving a loaded cask followed 
by a load tipover or fall 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask. 
6.3.5.1.1.2 Overturning or collision involving an LWT or an OWT holding a loaded 
cask (with impact limiters and personnel barrier installed) 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask. 
6.3.5.1.1.3 Collision of a railcar, an LWT, or OWT carrying a loaded cask (with impact 
limiters and personnel barrier installed) with the entrance vestibule doors 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask. 
6.3.5.1.1.4 The entrance vestibule doors close on a railcar, an LWT, or an OWT 
carrying a loaded cask (with impact limiters and personnel barrier installed) 
Transportation casks with impact limiters are designed to withstand, without breaching, the drops 
discussed in Section 4.2.1. The drops specified in Section 4.2.1 bound the impacts that could 
occur during cask handling at the repository. Consequently, a derailment, overturning, or 
collision would not breach a transportation cask. 
6.3.5.1.1.5 Collision of the gantry crane carrying a loaded MSC with the entrance 
vestibule doors 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 278 April 2005 
6.3.5.1.1.6 The entrance vestibule doors close on the entrance vestibule gantry crane 
carrying a loaded MSC 
A design requirement is assumed to ensure that closure of the doors onto an MSC would not 
cause the crane to drop its load (Assumption 5.1.1.13). 
6.3.5.1.1.7 Collision of a mobile elevated platform with a loaded cask or the conveyance 
holding the cask during removal of personnel barriers and impact limiters or 
during survey activities 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.5.1.1.8 Drop or collision of personnel barriers or impact limiters from the entrance 
vestibule gantry crane onto or against the loaded cask 
Operational requirements will prevent initiation of an event sequence for this potential event 
(Assumption 5.1.1.30). 
6.3.5.1.1.9 Collision between a forklift and a loaded cask on a railcar, an LWT, an 
OWT, or the conveyance holding the cask, prior to or after the removal of 
impact limiters and personnel barrier 
Operational requirements are assumed to ensure that forklifts will not be operated in a manner 
that could breach a transportation cask (Assumption 5.1.1.41). 
6.3.5.1.1.10 Collision between a mobile elevated platform and a loaded cask on a railcar, 
an LWT, an OWT, or the conveyance holding the cask 
Transportation casks with impact limiters are designed to withstand, without breaching, the 
impacts discussed in Section 4.2.1. The impacts specified in Section 4.2.1 bound the impacts 
that could occur during cask handling at the repository. Consequently, a derailment, overturning, 
or collision would not breach a transportation cask. 
6.3.5.1.1.11 Collision between the entrance vestibule gantry crane carrying a loaded 
MSC and a forklift 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). Operational requirements are assumed to ensure that forklifts will not be operated in a 
manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.5.1.1.12 Collision between the entrance vestibule gantry crane carrying the loaded 
MSC and a mobile elevated platform 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). Operational requirements are assumed to ensure that mobile elevated platforms will 
not be operated in a manner that could breach an MSC (Assumption 5.1.1.41).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 279 April 2005 
6.3.5.1.1.13 Drop or collision of equipment from the entrance vestibule gantry crane 
(including handling equipment for personnel barriers, impact limiters, etc.) 
onto or against a loaded cask or loaded MSC 
Operational requirements will ensure that a drop or collision of handling equipment onto or 
against a transportation cask without impact limiters or an MSC would not breach the cask 
(Assumption 5.1.1.30). 
6.3.5.1.1.14 Slapdown of a loaded cask onto a railcar, a truck trailer, or the floor during 
upending of the cask to the vertical orientation (after removal of the impact 
limiters and personnel barrier) 
This potential event is covered by Section 6.3.1.1. 
6.3.5.1.1.15 Drop of a loaded cask in a horizontal position (such as the HI-STAR) from 
the entrance vestibule gantry crane onto the floor or back onto the railcar or 
truck trailer during the transfer from a railcar or truck trailer to the tilting 
frame. 
This potential event is covered by Section 6.3.1.1. 
6.3.5.1.1.16 Drop or collision of a loaded cask in a horizontal position (such as the HISTAR) 
from the entrance vestibule gantry crane onto or against a sharp 
object or the tilting frame during the transfer from a railcar or truck trailer 
to the tilting frame. 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.1.1.17 Drop of a loaded cask from the entrance vestibule gantry crane onto the floor 
during the transfer from a railcar, truck trailer, or tilting frame to the 
pedestal on an import-export trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.5.1.1.18 Drop of a loaded cask from the entrance vestibule gantry crane onto the 
pedestal on an import-export trolley during the transfer from a railcar, truck 
trailer, or tilting frame to the pedestal on an import-export trolley 
This potential event is covered by Section 6.3.1.1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 280 April 2005 
6.3.5.1.1.19 Drop or collision of a loaded cask from the entrance vestibule gantry crane 
onto or against a sharp object during the transfer from a railcar, truck 
trailer, or tilting frame to the pedestal on an import-export trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.1.1.20 Drop of a loaded MSC from the entrance vestibule gantry crane onto the 
floor during the transfer from the FHF pad to the pedestal on an importexport 
trolley 
The analysis of transportation cask drops (Section 6.3.1.1) bounds this potential event, with the 
number of MSCs being less than the number of casks. There are two transfers: (1) from the 
trolley to the FHF pad before aging and (2) after aging, from the FHF pad to the trolley. The 
event sequence involving breach and release involving SNF or HLW is Category 2. Naval 
canisters are omitted because they will not be sent to the aging pads (Assumption 5.2.1.20). It is 
assumed that MSCs may be loaded with up to five DOE SNF canisters when staging at the aging 
pads is required (Assumption 5.2.4.1). 
6.3.5.1.1.21 Drop of a loaded MSC from the entrance vestibule gantry crane onto the 
pedestal on an import-export trolley during the transfer from the FHF pad to 
the pedestal on an import-export trolley 
Section 6.3.5.1.1.20 includes this potential event. 
6.3.5.1.1.22 Drop or collision of a loaded MSC from the entrance vestibule gantry crane 
onto or against a sharp object during the transfer from the FHF pad to the 
pedestal on an import-export trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.1.1.23 Slapdown of a loaded cask in the entrance vestibule due to off-center cask 
lowering or drop onto the pedestal on an import-export trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.5.1.1.24 Slapdown of a loaded MSC in the entrance vestibule due to off-center MSC 
lowering or drop onto the pedestal or edge of the pedestal on an importexport 
trolley 
The analysis presented in Section 6.3.5.1.1.20 includes this potential event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 281 April 2005 
6.3.5.1.1.25 Handling equipment drop onto a loaded cask or loaded MSC 
Operational requirements will ensure that a drop of handling equipment onto a transportation 
cask without impact limiters or an MSC would not breach the cask (Assumption 5.1.1.30). 
6.3.5.1.2 Chemical Contamination/Flooding 
6.3.5.1.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
or during off-normal temperatures (e.g. during a failure of the cooling 
system) 
Because the SNF in this area is contained in a sealed transportation cask or MSC (BSC 2005 
[DIRS 171428], Section 6.6.4.1), this potential event will not occur unless an event sequence 
leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible outcome of an event 
that exposes SNF to air. The consequence analyses will account for the possibility of oxidation, 
if applicable. 
6.3.5.1.3 Explosion/Implosion 
6.3.5.1.3.1 Hydrogen explosion involving batteries on a forklift 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.1.3.2 Hydrogen explosion involving batteries on a mobile elevated platform. 
The waste is protected by transportation casks or MSCs while in the presence of batteries for 
heavy equipment. The magnitude of a potential hydrogen explosion involving batteries for 
heavy equipment will be insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.1.3.3 Hydrogen explosion involving batteries on the import-export trolley. 
The waste is protected by transportation casks or MSCs while in the presence of batteries for 
heavy equipment. The magnitude of a potential hydrogen explosion involving batteries for 
heavy equipment will be insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.1.3.4 Hydrogen explosion involving batteries on a site prime mover 
The waste is protected by transportation casks or MSCs while in the presence of batteries for 
heavy equipment. The magnitude of a potential hydrogen explosion involving batteries for 
heavy equipment will be insufficient to cause a radiological release (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 282 April 2005 
6.3.5.1.4 Fire, Thermal 
6.3.5.1.4.1 Electrical fire associated with the entrance vestibule gantry crane 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.4.2 Electrical fire associated with handling equipment or other entrance 
vestibule electrical equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.4.3 Fire/explosion (battery/electrical fire) involving a site prime mover pulling or 
pushing a conveyance holding a loaded cask 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.4.4 Fire/explosion (battery/electrical fire) associated with the import-export 
trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.4.5 Fire/explosion (battery/electrical fire) associated with a forklift. 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.4.6 Fire/explosion (battery/electrical fire) associated with the mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.4.7 Thermal hazard (from decay heat) associated with vertical orientation of a 
loaded cask 
Transportation casks are designed to withstand normal conditions of transport (including high 
ambient temperatures and insolation) and hypothetical accident conditions (including fire) 
(Section 4.2.1). These conditions bound the thermal effect of orienting the cask vertically rather 
than horizontally. This potential event will not cause oxidation of SNF leading to exposure of 
individuals to radiation because the waste is contained in a sealed cask (BSC 2005 [DIRS 
171428], Section 6.6.4.1).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 283 April 2005 
6.3.5.1.4.8 Transient combustible fire in the entrance vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.1.5 Radiation 
6.3.5.1.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.5.1.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.5.1.5.3 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.5.1.6 Fissile 
6.3.5.1.6.1 Criticality associated with a railcar (holding a loaded cask ) derailment or 
collision followed by a load tipover or fall and rearrangement of the cask 
internals 
A criticality is not credible because the design requirements and waste acceptance criteria will 
ensure criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.5.1.6.2 Criticality associated with an overturning or collision involving an LWT or 
an OWT holding a loaded cask and rearrangement of cask internals 
A criticality in the cask-receipt area of the FHF is not credible because design requirements and 
waste acceptance criteria will ensure criticality safety in transportation casks (Assumption 
5.1.1.4). 
6.3.5.1.6.3 Criticality associated with a drop or slapdown of a cask and a rearrangement 
of the container internals 
A criticality in the cask-receipt area of the FHF is not credible because design requirements and 
waste acceptance criteria will ensure criticality safety in transportation casks (Assumption 
5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 284 April 2005 
6.3.5.1.6.4 Criticality associated with a drop or slapdown of an MSC and a 
rearrangement of the container internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.5.1.6.5 Criticality associated with collision of the entrance vestibule gantry crane 
holding an MSC followed by a load drop or tipover and a rearrangement of 
the MSC internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.5.2 FHF Preparation Room 
6.3.5.2.1 Collision/Crushing 
6.3.5.2.1.1 Collision of a loaded cask or loaded MSC on a pedestal on an import-export 
trolley with the preparation room shield doors separating the FHF entrance 
vestibule from the preparation room 
Collisions involving trolleys are covered in Section 6.3.1.22. 
6.3.5.2.1.2 The preparation room shield doors separating the FHF entrance vestibule 
from the preparation room close on a loaded cask or loaded MSC on a 
pedestal on an import-export trolley 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley holding 
a loaded cask or MSC would not overturn the trolley or cause it to drop its load (Assumption 
5.1.1.13). Because the trolley remains upright there is no threat to the integrity of the cask. 
6.3.5.2.1.3 Derailment of an import-export trolley holding a loaded cask or loaded MSC 
on a pedestal (with outer and/or inner lid bolted in place, if applicable) 
followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the cask to fall 
off the trolley (Assumption 5.1.1.36), thereby making this event Beyond Category 2. Because 
the cask remains upright there is no threat to the integrity of the unsealed WP. 
6.3.5.2.1.4 Drop or collision of tools or equipment (including a lid-lifting fixture, lid 
bolts, etc.) onto or against a loaded cask or loaded MSC outer lid (if 
applicable) or a cask or MSC inner lid in the preparation room 
Operational requirements will ensure that this potential event will not initiate an event sequence 
when the inner lid is exposed (Assumption 5.1.1.32). If inner lid is protected by the outer lid, the 
conclusion that an event sequence will not be initiated still holds.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 285 April 2005 
6.3.5.2.1.5 Collision of a mobile elevated platform with a loaded cask or loaded MSC 
during preparation activities on top of the cask or MSC 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.5.2.1.6 Drop of a cask or MSC outer lid onto the loaded cask or loaded MSC (if 
applicable) in the preparation room 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event sequence discussed in Section 6.3.1.2. The frequency is bounded because this event only 
applies to transportation casks and MSCs, while the bounding event also applies to WPs. The 
consequences are bounded because the contents of the cask are protected by the inner lid for this 
event, whereas no lids are in place for the bounding event. 
6.3.5.2.1.7 Derailment of an import-export trolley holding a loaded cask or loaded MSC 
on a pedestal (with outer lid removed [if applicable] and inner lid unbolted 
but in place) followed by a load tipover or fall 
A design requirement is assumed to ensure that the import-export trolley holding a loaded cask 
on a pedestal will not derail or allow the cask to fall off the trolley (Assumption 5.1.1.36). 
Because the trolley remains upright there is no threat to the integrity of the cask. 
6.3.5.2.1.8 Collision of an import-export trolley holding a loaded cask or loaded MSC 
on a pedestal (with outer lid removed [if applicable] and inner lid unbolted 
but in place) with shield doors separating the preparation room and the main 
transfer room 
Collisions involving trolleys are covered in Section 6.3.1.22. 
6.3.5.2.1.9 Closure of the shield doors separating the preparation room and the main 
transfer room onto the import-export trolley holding a loaded cask or loaded 
MSC on a pedestal (with outer lid removed [if applicable] and inner lid 
unbolted but in place) 
A design requirement is assumed to ensure that closure of the airlock and shield doors onto a 
trolley would not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because 
the trolley remains upright there is no threat to the integrity of the cask. 
6.3.5.2.2 Chemical Contamination/Flooding 
6.3.5.2.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
High temperatures could lead to oxidation of the CSNF matrix whenever CSNF assemblies with 
failed cladding is exposed to air. Oxidation of failed CSNF assemblies is expected as a part of 
normal operations wherever CSNF assemblies are exposed to air. Resulting exposure of workers 
to radiation will be managed as a normal-operations dose by procedures for monitoring radiation
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 286 April 2005 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
See Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.5.2.3 Explosion/Implosion 
6.3.5.2.3.1 Cask sampling and inerting system (or other pneumatic or pressurized 
system) missile due to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.5.2.3.2 Explosion hazard associated with the cask sampling and inerting system and 
the ignition of hydrogen that may have accumulated in the cask 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.5.2.3.3 Hydrogen explosion involving batteries on the import-export trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.2.3.4 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.2.4 Fire, Thermal 
6.3.5.2.4.1 Electrical fire associated with handling equipment or other preparation 
room equipment, including the main transfer room overhead crane (which 
can access the preparation room via an overhead hatch) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.2.4.2 Fire/explosion (battery/electrical fire) associated with the import-export 
trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.2.4.3 Fire/explosion (battery/electrical fire) associated with the mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 287 April 2005 
6.3.5.2.4.4 Transient combustible fire in the preparation area 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.2.4.5 Thermal hazard (from decay heat) associated with vertical orientation of the 
loaded cask 
This hazard is addressed in Section 6.3.5.2.2.1. 
6.3.5.2.4.6 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.5.2.5 Radiation 
6.3.5.2.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.5.2.5.2 Damage or rupture of cask sampling and purging system, leading to a release 
of cask internal gases and radioactive material 
The sampling operation will be conducted so that exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. (BSC 2004 
[DIRS 172098], Section 3.2.2.1.1). Although a rupture leading to a radiological release would 
be an abnormal occurrence, radiation protection programs will ensure that such an occurrence 
would not contribute significantly to the normal operations dose. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.5.2.5.3 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Exposure of workers to radiation due to this potential event will be managed as a normaloperations 
dose by procedures for monitoring radiation doses and assigning work, which ensure 
that workers do not receive excessive radiation doses. See Section 7.4 for a list of potential 
events and conditions that are treated as normal operations. 
6.3.5.2.5.4 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 288 April 2005 
6.3.5.2.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.5.2.6 Fissile 
6.3.5.2.6.1 Criticality associated with a loaded cask or loaded MSC collision or trolley 
derailment followed by a load tipover or fall and a rearrangement of the cask 
internals 
A criticality will not occur because design requirements and waste acceptance criteria will ensure 
criticality safety in transportation casks (Assumption 5.1.1.4). 
6.3.5.3 FHF Entrance Vestibule, Preparation Room, Main Transfer Room, and Fuel 
Transfer Bay (Empty WP/Empty MSC Processing) 
No potential event sequences have been identified that affect a waste form. 
6.3.5.4 FHF Main Transfer Room, Fuel Transfer Bay, Fuel Transfer Room (SNF 
Assembly Transfer) 
6.3.5.4.1 Collision/Crushing 
6.3.5.4.1.1 Derailment of the import-export trolley holding a loaded cask or loaded 
MSC on a pedestal (with inner lid in place, unbolted) followed by a load 
tipover or fall 
A design requirement is assumed to ensure that the trolley holding a loaded cask on a pedestal 
will not derail or allow the cask to fall off the trolley (Assumption 5.1.1.36). Because the trolley 
remains upright there will be no event sequence. 
6.3.5.4.1.2 Drop of a loaded cask or MSC (with inner lid in place, unbolted) onto the 
floor during the lift using the overhead bridge crane from the import-export 
trolley to the cask transfer trolley or MSC trolley, respectively 
Transportation cask drops are covered in Section 6.3.1.1.1. MSC drops are covered in 6.3.1.1.2. 
6.3.5.4.1.3 Drop of a loaded cask or MSC (with inner lid in place, unbolted) onto the 
trolley during the lift using the overhead bridge crane from the importexport 
trolley to the cask transfer trolley or MSC trolley, respectively 
Transportation cask drops are covered in Section 6.3.1.1.1. MSC drops are covered in 6.3.1.1.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 289 April 2005 
6.3.5.4.1.4 Drop or collision of a loaded cask or MSC (with inner lid in place, unbolted) 
onto or against a sharp object during the lift using the overhead bridge crane 
from the import-export trolley to the cask transfer trolley or MSC trolley, 
respectively 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.4.1.5 Slapdown of a loaded cask or MSC (with inner lid in place, unbolted) 
following a drop from the overhead bridge crane onto the edge of the 
pedestal, trolley, or other object during the transfer from the import-export 
trolley to the cask transfer trolley or MSC trolley, respectively 
Transportation cask drops are covered in Section 6.3.1.1.1. MSC drops are covered in 6.3.1.1.2. 
6.3.5.4.1.6 Drop or collision of a docking ring onto or against a loaded cask or loaded 
MSC prior to entering the fuel transfer bay for unloading 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.5.4.1.7 Collision of a mobile elevated platform with a loaded cask or loaded MSC 
during docking ring installation activities associated with the cask or MSC 
prior to entering the fuel transfer bay for unloading 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach or overturn a transportation cask (Assumption 5.1.1.41). 
6.3.5.4.1.8 Drop or collision of a manipulator, handling equipment, or other 
miscellaneous equipment onto or against a loaded cask or loaded MSC prior 
to entering the fuel transfer bay for unloading 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.5.4.1.9 Derailment of the cask transfer trolley or MSC trolley holding a loaded cask 
or loaded MSC, respectively, on a pedestal (with inner lid in place, unbolted) 
followed by a load tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the cask or 
MSC to fall off the trolley (Assumption 5.1.1.36).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 290 April 2005 
6.3.5.4.1.10 Collision of a trolley holding a loaded cask or loaded MSC on a pedestal 
(with outer lid removed [if applicable] and inner lid unbolted but in place) 
with shield doors separating the main transfer room and the fuel transfer 
bay 
Trolley collisions are covered in Section 6.3.1.22. 
6.3.5.4.1.11 Closure of the shield doors separating the main transfer room and the fuel 
transfer bay onto the trolley holding a loaded cask or loaded MSC on a 
pedestal (with outer lid removed [if applicable] and inner lid unbolted but in 
place) 
A design requirement is assumed to ensure that closure of shield doors onto a trolley would not 
overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright there will be no event sequence as a result of this potential event. 
6.3.5.4.1.12 Drop or collision of [components associated with] a docking port onto or 
against a cask or MSC 
A design requirement is assumed to ensure that this potential event will not initiate an event 
sequence (Assumption 5.1.1.17). 
6.3.5.4.1.13 Drop or collision of a docking port plug onto or against a cask lid or MSC lid 
(with outer lid removed [if applicable] and inner lid unbolted but in place) 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37). 
6.3.5.4.1.14 Drop of an inner lid on a cask or MSC (with outer lid removed [if 
applicable]) 
This potential event is included in Section 6.3.1.2. 
6.3.5.4.1.15 Drop or collision of an SNF assembly from the spent fuel transfer machine 
back into or against a cask or MSC being unloaded 
This potential event is included in Section 6.3.1.3. 
6.3.5.4.1.16 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against one or more SNF assembly(ies) in the cask or MSC being 
unloaded or onto one or more SNF assembly(ies) in the WP or MSC being 
loaded 
This potential event is included in Section 6.3.1.3.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 291 April 2005 
6.3.5.4.1.17 Impact due to horizontal movement of an SNF assembly by the spent fuel 
transfer machine before the assembly is completely removed from the cask 
or MSC 
This potential event is included in Section 6.3.1.3. 
6.3.5.4.1.18 Drop of an SNF assembly from the spent fuel transfer machine onto the fuel 
transfer room floor 
This potential event is included in Section 6.3.1.3. 
6.3.5.4.1.19 Collision involving an SNF assembly suspended from the spent fuel transfer 
machine with wall-mounted equipment located in the fuel transfer room. 
This potential event is included in Section 6.3.1.3. 
6.3.5.4.1.20 Drop or collision of an SNF assembly from the spent fuel transfer machine 
onto or against a sharp object 
Assemblies are assumed to breach when they are dropped or involved in a collision. The 
calculation in Section 6.3.1.3 includes the potential event. 
6.3.5.4.1.21 Drop or collision of an SNF assembly from the spent fuel transfer machine 
into or against an empty WP or MSC being loaded 
This potential event is included in Section 6.3.1.3. 
6.3.5.4.1.22 Drop and slapdown of an SNF assembly from the spent fuel transfer machine 
(due to impact with an edge of the cask, MSC, WP, floor edge, WP internal 
baffle, etc.) during the transfer from the cask or MSC to a WP or MSC 
This potential event is included in Section 6.3.1.3. 
6.3.5.4.1.23 Drop or collision of handling equipment into or against an open MSC or an 
open WP filled with commercial SNF assemblies 
Drops of handling equipment onto CSNF assemblies are treated in Section 6.3.1.4. 
6.3.5.4.1.24 Drop of a WP inner lid or MSC cask inner lid (as appropriate) from the fuel 
transfer room crane onto a loaded WP or loaded MSC 
The calculation in Section 6.3.1.2 includes this potential event. 
6.3.5.4.1.25 Drop or collision of a transfer port seal plug from the fuel transfer room 
crane onto or against the inner lid of a loaded WP or a loaded MSC 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 292 April 2005 
6.3.5.4.2 Chemical Contamination/Flooding 
6.3.5.4.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
High temperatures could lead to oxidation of the CSNF matrix whenever CSNF assemblies with 
failed cladding is exposed to air. Oxidation of failed CSNF assemblies is expected as a part of 
normal operations wherever CSNF assemblies are exposed to air. Resulting exposure of workers 
to radiation will be managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
See Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.5.4.3 Explosion/Implosion 
6.3.5.4.3.1 Hydrogen explosion involving batteries on a cask transfer trolley or an MSC 
trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.4.3.2 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.4.4 Fire, Thermal 
6.3.5.4.4.1 Electrical fire associated with SNF handling equipment or other electricallypowered 
equipment in the main transfer room, the fuel transfer bays, or the 
fuel transfer room (including the overhead cranes and the spent fuel transfer 
machine) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.4.4.2 Fire/explosion (battery/electrical fire) associated with an import-export 
trolley, a cask transfer trolley, or an MSC trolley holding a filled or partially 
filled cask or MSC, respectively, with or without inner lid in place (but not 
sealed) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 293 April 2005 
6.3.5.4.4.3 Electrical fire associated with a WP trolley holding a partially filled or filled 
WP, with or without inner lid in place (but not sealed). 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.4.4.4 Fire/explosion (battery/electrical fire) associated with the mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.4.4.5 HEPA filter fire due to excessive radioactive decay within the filter bed 
HEPA filters will be maintained well below their auto-ignition temperature to preclude a filter 
fire (Assumption 5.1.1.47). 
6.3.5.4.4.6 Intact or non-intact SNF overheating due to a loss of cooling resulting in 
excessive temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.5.4.4.7 Thermal hazard (from decay heat) associated with a vertical orientation of a 
loaded cask (sealed/inerted or unsealed/non-inerted) or loaded, 
unsealed/non-inerted WP 
This potential event is discussed in Section 6.3.5.4.2.1. 
6.3.5.4.4.8 Transient combustible fire in the main transfer room, the fuel transfer bays, 
or the fuel transfer room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.4.5 Radiation 
6.3.5.4.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.5.4.5.2 Docking ring failure leads to a radiological release 
This potential event is covered in Section 6.3.1.25.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 294 April 2005 
6.3.5.4.5.3 Radiological release due to installation of incorrect docking ring 
Docking ring failure has the same consequences as installation of an incorrect docking ring. 
Therefore, the analysis in Section 6.3.1.25 applies to this potential event. 
6.3.5.4.5.4 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.5.4.5.5 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne 
contamination 
This potential event is covered in Section 6.3.1.25. 
6.3.5.4.5.6 Inadvertent opening of a fuel transfer bay door, leading to a worker 
exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.5.4.5.7 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.5.4.6 Fissile 
6.3.5.4.6.1 Criticality associated with a drop or slapdown of a loaded, unsealed cask or 
MSC from the main transfer room overhead crane and a rearrangement of 
the container internals 
A criticality will not occur because design requirements and waste acceptance criteria will ensure 
criticality safety in transportation casks and MSCs (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 295 April 2005 
6.3.5.4.6.2 Criticality associated with an import-export trolley, a cask transfer trolley, 
or an MSC trolley holding a loaded, unsealed cask or MSC (as applicable) 
derailment followed by a load tipover or fall and a rearrangement of the 
container internals 
A criticality in a cask or MSC is not credible because a design requirement will ensure that casks 
and MSCs remain subcritical even with the most reactive credible configuration of the fissile 
material and optimal moderation (Assumption 5.1.1.4). 
6.3.5.4.6.3 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine into a cask, MSC, or WP and a rearrangement of the cask, 
MSC, or WP internals 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumptions 5.1.1.4, 5.1.3.1, and 5.1.3.2). 
6.3.5.4.6.4 Criticality associated with a drop of an SNF assembly from the spent fuel 
transfer machine and a rearrangement of the fuel rods that comprise the 
assembly due to impact 
Design calculations and the resulting design requirements will ensure criticality safety for this 
event (Assumptions 5.1.1.4, 5.1.3.1, and 5.1.3.2). 
6.3.5.4.6.5 Criticality associated with the drop of heavy equipment onto a loaded, open 
cask, MSC, or WP and a rearrangement of the container internals 
Equipment drop onto a transportation cask, or MSC will not lead to a criticality because design 
requirements and waste acceptance criteria will ensure criticality safety in transportation casks 
(Assumption 5.1.1.4). Equipment drop onto a WP will not lead to criticality because: 
 A design requirement will ensure that WPs are subcritical provided that moderator control is 
in effect (Assumptions 5.1.3.2 and 5.1.1.21). 
 Design features of the WP will ensure that an open WP suffering an impact from heavy 
equipment drop will not become critical (Assumption 5.1.3.2). 
6.3.5.4.6.6 Criticality associated with a misload of a WP or an MSC 
WPs are designed such that no combination of CSNF assemblies that may be accepted for 
disposal could lead to a nuclear criticality inside the WP provided that moderator control is in 
effect (Assumptions 5.1.3.2 and 5.1.1.21). MSCs are designed to remain subcritical with 
optimum moderation and most reactive waste forms (Assumption 5.1.1.4). Therefore, a 
preclosure criticality due to misload is not credible and administrative controls on container 
loading are not relied upon to prevent preclosure criticality.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 296 April 2005 
6.3.5.5 FHF Main Transfer Room (Canister Transfer) 
6.3.5.5.1 Collision/Crushing 
6.3.5.5.1.1 Drop of a loaded cask (with inner lid in place, unbolted) from the main 
transfer room overhead crane onto the floor during the transfer from a 
pedestal on the import-export trolley to the cask transfer station 
Cask drops are covered in Section 6.3.1.1. 
6.3.5.5.1.2 Drop or collision of a loaded cask (with inner lid in place, unbolted) from the 
main transfer room overhead crane onto or against a sharp object during the 
transfer from a pedestal on the import-export trolley to the cask transfer 
station 
An operational requirement will ensure that the load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.5.1.3 Drop or collision of a loaded cask (with inner lid in place, unbolted) from the 
main transfer room overhead crane into or against the canister transfer 
station 
Cask drops are covered in Section 6.3.1.1. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.4 Slapdown of a loaded cask (with inner lid in place, unbolted) in the main 
transfer room due to a cask corner drop from the main transfer room 
overhead crane onto the edge of the pedestal or import-export trolley 
This potential event is covered by Section 6.3.1.1. 
6.3.5.5.1.5 Drop or collision of a loaded cask (with inner lid in place, unbolted) from the 
main transfer room overhead crane into or against the canister transfer 
station 
Cask drops are covered in Section 6.3.1.1. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.6 Slapdown of a loaded cask (with inner lid in place, unbolted) onto the floor, 
cask slapdown into the canister transfer station, or cask slapdown into a 
wall; all due to off-center cask lowering into the canister transfer station 
This potential event is covered by Section 6.3.1.1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 297 April 2005 
6.3.5.5.1.7 Drop or collision of a manipulator, handling equipment, or other 
miscellaneous equipment onto or against a loaded cask (with inner lid in 
place, unbolted) prior to entering the canister transfer station for unloading 
Operational requirements will ensure that a drop of handling equipment onto a transportation 
cask without impact limiters or an MSC would not breach the cask (Assumption 5.1.1.30). 
6.3.5.5.1.8 Drop of a cask inner lid, as appropriate, from the main transfer room 
overhead crane into a loaded cask to be unloaded 
The calculation in Section 6.3.1.2 includes this potential event. 
6.3.5.5.1.9 Drop or collision of handling equipment into or against an open cask loaded 
with a DPC, a DOE HLW canister, a naval SNF canister, or a [standardized] 
DOE SNF canister 
This potential event is included in Section 6.3.1.6. For DPC canisters, no credit is taken for the 
prevention or mitigation of a release that may be provided by the canister. 
6.3.5.5.1.10 Drop or collision of a DPC, a DOE HLW canister, a [standardized] DOE 
SNF canister, or a naval SNF canister from the main transfer room overhead 
crane back into or against the cask being unloaded 
Section 6.3.1.5 includes the potential drop event. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.11 Impact due to horizontal movement of a naval SNF canister, a DPC, a DOE 
HLW canister, or a [standardized] DOE SNF canister with the main transfer 
room overhead crane before the canister is completely removed from the 
cask 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.5.5.1.12 Drop and slapdown of a naval SNF canister, a DOE HLW canister or a 
[standardized] DOE SNF canister from the main transfer room overhead 
crane into the side of the canister transfer station (due to impact with an edge 
of the cask, MSC, WP, floor edge, WP or MSC internal baffle, etc.) during 
the transfer from the cask to a WP or MSC (as appropriate) 
Section 6.3.1.5 includes this potential event. 
6.3.5.5.1.13 Drop and slapdown of a DPC from the main transfer room overhead crane 
into the side of the canister transfer station (due to impact with an edge of 
the cask, MSC, floor edge, MSC internal baffle, etc.) during the transfer 
from the cask to an MSC 
This potential event is included in Section 6.3.1.5.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 298 April 2005 
6.3.5.5.1.14 Drop or collision of a DPC, a DOE HLW canister, a [standardized] DOE 
SNF canister, or a naval SNF canister from the main transfer room overhead 
crane onto or against a sharp object or edge in the canister transfer station 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.5.1.15 Drop of a DPC, a DOE HLW canister, a [standardized] DOE SNF canister, 
or a naval SNF canister from the main transfer room overhead crane onto 
the canister transfer station floor 
This potential event is included in Section 6.3.1.5. 
6.3.5.5.1.16 Drop or collision of a DOE HLW canister, a [standardized] DOE SNF 
canister, or a naval SNF canister from the main transfer room crane into or 
against an empty WP or empty MSC 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.17 Drop or collision of a naval SNF canister from the main transfer room crane 
into or against an empty WP 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.18 Drop or collision of a DPC from the main transfer room crane into or against 
an empty MSC 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.19 Collision involving a DPC, a DOE HLW canister, a [standardized] DOE SNF 
canister, or a naval SNF canister and the canister transfer station 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.5.5.1.20 Drop or collision of a DOE HLW canister from the main transfer room 
overhead crane onto or against another DOE HLW canister or a 
[standardized] DOE SNF canister in a WP or in an MSC 
The potential drop event is included in Section 6.3.1.5. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 299 April 2005 
6.3.5.5.1.21 Drop or collision of a [standardized] DOE SNF canister from the main 
transfer room overhead crane onto or against a DOE HLW canister in a WP 
or in an MSC 
The drop event is covered in Section 6.3.1.5. Crane-load collisions do not initiate Category 1 or 
Category 2 event sequences (Section 6.3.1.21). 
6.3.5.5.1.22 Drop or collision of handling equipment into or against an open WP or MSC 
loaded with a DPC, DOE HLW canisters, and/or [standardized] DOE SNF 
canisters, and/or a naval SNF canister, as appropriate 
This potential event is included in Section 6.3.1.6. For DPC canisters, no credit is taken for the 
prevention or mitigation of a release that may be provided by the canister. 
6.3.5.5.1.23 Drop of a WP inner lid or MSC cask inner lid, as appropriate, from the main 
transfer room overhead crane onto a filled (loaded) WP or loaded MSC 
The calculation in Section 6.3.1.2 includes this potential event. 
6.3.5.5.2 Chemical Contamination/Flooding 
6.3.5.5.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because this section considers SNF in sealed canisters only (BSC 2005 [DIRS 171428], Section 
6.6.4.5), this potential event will not occur unless an event sequence leads to exposure of SNF to 
air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to air. The 
consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.5.5.3 Explosion/Implosion 
6.3.5.5.3.1 Hydrogen explosion involving batteries on the import-export trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.5.3.2 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 300 April 2005 
6.3.5.5.4 Fire, Thermal 
6.3.5.5.4.1 Electrical fire associated with SNF and HLW handling equipment in the 
main transfer room (including the overhead crane, manipulators, the 
movable platform/sleeve assembly, etc. ) 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.5.4.2 Fire/explosion (battery/electrical fire) associated with the import-export 
trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.5.4.3 Fire/explosion (battery/electrical fire) associated with the mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.5.4.4 Thermal hazard (from decay heat) associated with a vertical orientation of a 
loaded cask (with inner lid in place, unbolted) 
This hazard is addressed in Section 6.3.5.5.2.1. 
6.3.5.5.4.5 Overheating of a loaded cask, WP, or MSC due to a loss of cooling resulting 
in excessive temperature and possible damage to canister contents 
This potential event is discussed in Section 6.3.1.26. 
6.3.5.5.4.6 Transient combustible fire in the main transfer room 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.5.5 Radiation 
6.3.5.5.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.5.5.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne 
contamination 
This potential event is covered in Section 6.3.1.25.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 301 April 2005 
6.3.5.5.5.3 Thermal expansion of gases or other loss of confinement in an unsealed cask, 
leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.5.5.5.4 Inadvertent opening of the main transfer room shield door, leading to a 
worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.5.5.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.5.5.6 Fissile 
6.3.5.5.6.1 Criticality associated with a drop or slapdown of a loaded cask or MSC from 
the main transfer room overhead crane and a rearrangement of the cask or 
MSC internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.5.5.6.2 Criticality associated with a drop or slapdown of a DPC, a [standardized] 
DOE SNF canister, a naval SNF canister, or a DOE HLW canister and a 
rearrangement of canister internals 
Design calculations will show that dropping a DOE SNF canister within its design basis will not 
lead to a criticality if moderator control is in effect (Assumption 5.1.1.3). A waste acceptance 
criterion will ensure that DPCs are designed such that drops, collisions, and other handling 
impacts (allowing for rearrangement of container internals and optimal moderator intrusion) 
cannot lead to a nuclear criticality (Assumption 5.1.1.4). The potential for criticality for naval 
canisters is addressed in Attachment I, where it is demonstrated that a criticality associated with 
the drop of a naval canister is Beyond Category 2. There is no potential for criticality of HLW 
canisters (Assumption 5.2.1.19).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 302 April 2005 
6.3.5.5.6.3 Criticality associated with the drop of heavy equipment onto a loaded, open 
cask, MSC, or WP and a rearrangement of the container internals 
Equipment drop onto a transportation cask or MSC will not lead to a criticality because design 
requirements and waste acceptance criteria will ensure criticality safety in transportation casks 
and MSCs (Assumption 5.1.1.4). Equipment drop onto a WP will not lead to criticality because 
(1) a design requirement will ensure that WPs are subcritical provided that moderator control is 
in effect (Assumptions 5.1.3.2 and 5.1.1.21) and (2) design features of the WP will ensure that a 
WP suffering an impact from heavy equipment drop will not become critical (Assumptions 
5.1.3.1). 
6.3.5.5.6.4 Criticality associated with a misload of a WP or an MSC 
WPs are designed such that no combination of CSNF assemblies that may be accepted for 
disposal could lead to a nuclear criticality inside the WP provided that moderator control is in 
effect (Assumptions 5.1.3.2 and 5.1.1.21). MSCs are designed to remain with optimum 
moderation and most reactive waste forms (Assumption 5.1.1.4). Therefore, a preclosure 
criticality due to misload is not credible and administrative controls on container loading are not 
relied upon to prevent preclosure criticality. 
6.3.5.6 FHF Main Transfer Room, WP Positioning Cell, WP Closure Cell (WP 
Closure) 
6.3.5.6.1 Collision/Crushing 
6.3.5.6.1.1 Collision involving the trolley holding the loaded, unsealed WP and the 
shield doors between the main transfer room and the WP positioning cell 
Trolley collisions are covered in Section 6.3.1.22. 
6.3.5.6.1.2 Shield doors between the main transfer room and the WP positioning cell 
close on the trolley holding the loaded, unsealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Only the stainless 
steel inner lid will have been installed before this event occurs. Because the trolley remains 
upright there is no threat to the integrity of the loaded, unsealed WP. Therefore, unplanned 
radiological exposure will not occur as a result of this potential event. 
6.3.5.6.1.3 Derailment of a trolley holding a loaded, unsealed WP followed by a load 
tipover or fall 
A design requirement is assumed to ensure that loaded transfer trolleys will not derail or allow 
the WP to fall off the trolley (Assumption 5.1.1.36). Because the trolley remains upright, the 
WP will not spill its contents and no event sequence will occur.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 303 April 2005 
6.3.5.6.1.4 Drop or collision of equipment from a main transfer room overhead crane, 
including a docking ring, lifting equipment, or a lifting fixture, onto or 
against a loaded, unsealed WP or WP inner lid 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.5.6.1.5 Drop or collision of an unsealed, loaded WP from the main transfer room 
overhead crane back into or against the canister transfer station 
Section 6.3.1.7 includes the potential drop event. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.6.1.6 Drop of an unsealed, loaded WP from the main transfer room overhead 
crane onto the main transfer room floor during the lift and transfer to the 
WP positioning cell pedestal and trolley 
Section 6.3.1.7 includes this potential event. 
6.3.5.6.1.7 Drop of an unsealed, loaded WP from the main transfer room overhead 
crane onto the pedestal on the WP positioning cell trolley during the lift and 
transfer to the WP positioning cell pedestal and trolley 
Section 6.3.1.7 includes this potential event. 
6.3.5.6.1.8 Drop or collision of an unsealed, loaded WP from the main transfer room 
overhead crane onto or against a sharp object during the lift and transfer to 
the WP positioning cell pedestal and trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.6.1.9 Slapdown of a loaded, unsealed WP onto the floor, into a wall, or into nearby 
equipment following a drop from the main transfer room overhead crane 
onto the edge of the trolley, pedestal, or other equipment during the lift and 
transfer to the WP positioning cell pedestal and trolley 
Section 6.3.1.7 includes this potential event. 
6.3.5.6.1.10 Lid drop onto a WP from the lid placement fixture equipment during the 
welding process 
The frequency and consequences of this event are bounded by those of the Category 2 lid-drop 
event sequence discussed in Section 6.3.1.2. The frequency is bounded because the bounding 
event applies to WPs, MSCs, and transportation casks, whereas the present event applies only to 
WPs. The consequences are bounded because the contents of the cask are protected by the inner 
lid for this event, whereas no lids are in place for the bounding event.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 304 April 2005 
6.3.5.6.1.11 Equipment drop onto a WP during the welding process 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.5.6.1.12 Drop or collision of equipment from a main transfer room overhead crane 
onto or against a loaded, sealed WP positioned on a pedestal on a trolley 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.5.6.1.13 Collision involving the trolley holding the loaded, sealed WP and the shield 
doors between the WP positioning cell and the main transfer room 
Trolley collisions are covered in Section 6.3.1.22. 
6.3.5.6.1.14 Shield doors between the WP positioning cell and the main transfer room 
close on the trolley holding the loaded, sealed WP 
A design requirement is assumed to ensure that closure of the shield doors onto a trolley would 
not overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright the WP will not breach no event sequence will result. 
6.3.5.6.2 Chemical Contamination/Flooding 
6.3.5.6.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Oxidation of failed CSNF assemblies is expected as a part of normal operations wherever CSNF 
assemblies are exposed to air. Resulting exposure of workers to radiation will be managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, which 
ensure that workers do not receive excessive radiation doses. See Section 7.4 for a list of 
potential events and conditions that are treated as normal operations. 
6.3.5.6.3 Explosion/Implosion 
6.3.5.6.3.1 Explosion hazard associated with the WP purging and inerting system and 
the ignition of hydrogen that may have accumulated in the WP 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.5.6.3.2 WP inerting system (or other pneumatic or pressurized system) missile due 
to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 305 April 2005 
6.3.5.6.3.3 Hydrogen explosion involving batteries on the WP closure transfer trolley 
The waste is protected by the WP while in the presence of batteries for heavy equipment. The 
magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a WP breach (Assumption 5.1.1.51). 
6.3.5.6.4 Fire, Thermal 
6.3.5.6.4.1 Electrical fire associated with handling equipment or other electricallypowered 
equipment in the WP closure cell and the WP positioning cell, 
including the overhead cranes and the welding subsystem in the WP closure 
cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.6.4.2 Fire/explosion (battery/electrical fire) associated with the WP transfer trolley 
holding a loaded, unsealed WP or a WP closure transfer trolley holding a 
loaded, unsealed or sealed WP 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.6.4.3 Intact or non-intact SNF overheating or damage to canister contents due to a 
loss of cooling resulting in excessive temperature and possible zircaloy 
cladding (or other cladding) unzipping or cladding failure due to excessive 
hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.5.6.4.4 Canister/fuel damage by burn-through during welding process/heat damage 
Burn-through of the inner lid is not possible with the gas tungsten arc welding process, which is 
used for the closure welds (BSC 2005 [DIRS 171428], Section 6.6.3.10; BSC 2004 [DIRS 
172428], Section 3). 
6.3.5.6.4.5 Thermal hazard/canister contents overheating/SNF assemblies overheating 
in a WP during the welding process resulting in excessive cladding 
temperature and possible zircaloy cladding (or other cladding) unzipping 
Overheating of the WP contents due to welding is not possible using the gas tungsten arc 
welding process, which is used for the closure welds (BSC 2005 [DIRS 171428], Section 
6.6.3.10; BSC 2004 [DIRS 172428], Section 3). 
6.3.5.6.4.6 Transient combustible fire in the WP closure cell and the WP positioning cell 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 306 April 2005 
6.3.5.6.5 Radiation 
6.3.5.6.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.5.6.5.2 Glovebox leak leads to a radiological release 
Exposure of workers to radiation due to a glovebox leak will be managed as a normal-operations 
dose by procedures for monitoring radiation doses and assigning work, which ensure that 
workers do not receive excessive radiation doses. See Section 7.4 for a list of potential events 
and conditions that are treated as normal operations. 
6.3.5.6.5.3 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.5.6.5.4 Inadvertent opening of a transfer bay shield door or the WP positioning cell 
shield door, leading to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.5.6.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.5.6.6 Fissile 
6.3.5.6.6.1 Criticality associated with a trolley holding a sealed or unsealed WP 
derailment followed by a load tipover or fall and rearrangement of the 
container internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). 
6.3.5.6.6.2 Criticality associated with a drop or slapdown of a loaded, unsealed WP 
from the main transfer room overhead crane and a rearrangement of the 
container internals 
Because the WP does not spill its contents (Assumption 5.1.3.11) and moderators are excluded 
from the WP (Assumptions 5.1.3.2 and 5.1.1.21), the unsealed WP will remain subcritical.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 307 April 2005 
6.3.5.6.6.3 Criticality associated with the drop of heavy equipment onto a loaded, 
unsealed WP and a rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). A design 
requirement will also ensure that unsealed WPs cannot become critical with moderator control in 
effect (Assumption 5.1.3.2). 
6.3.5.7 FHF Main Transfer Room, Preparation Room, Entrance Vestibule (WP 
Loadout) 
6.3.5.7.1 Collision/Crushing 
6.3.5.7.1.1 Derailment of a trolley holding a loaded, sealed WP followed by a load 
tipover or fall 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright there is no 
threat to the integrity of the unsealed WP. 
6.3.5.7.1.2 Drop of a loaded, sealed WP from a main transfer room overhead crane onto 
the floor during transfer from the trolley to the survey area or from the 
survey area to the tilting machine 
This potential event is covered by Section 6.3.1.8. 
6.3.5.7.1.3 Drop or collision of a loaded, sealed WP from a main transfer room overhead 
crane onto or against a sharp object (including the tilting machine) during 
transfer from the trolley to the survey area or from the survey area to the 
tilting machine 
A design requirement will ensure that operating areas are free of design features that could cause 
a puncture in case of a drop (Assumption 5.1.1.40). Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.7.1.4 Slapdown of a loaded, sealed WP from a main transfer room overhead crane 
to the cell floor during transfer from the trolley to the survey area due to 
drop from the overhead crane onto the edge of the pedestal on the trolley, the 
edge of the trolley, or another object on the floor 
Section 6.3.1.8 includes this potential event. The WP is assumed to survive a slapdown without 
breach (Assumption 5.1.3.12).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 308 April 2005 
6.3.5.7.1.5 Slapdown (either forward into the WP turntable or backward onto the floor) 
of a loaded, sealed WP in the tilting machine from a main transfer room 
overhead crane during the lowering of the WP to the horizontal position on 
the pallet previously placed on the WP turntable 
Section 6.3.1.8 includes this potential event. The WP is assumed to survive a slapdown without 
breach (Assumption 5.1.3.12). A design requirement is assumed to prevent backward slapdowns 
(Assumption 5.1.1.53). 
6.3.5.7.1.6 Collision of the tilting machine against a loaded, sealed WP on a pallet on the 
WP turntable 
A design or operational requirement is assumed to ensure that a collision between the tilting 
machine and a WP would not breach the WP (Assumption 5.1.3.10). 
6.3.5.7.1.7 Drop or collision of a lifting collar from a main transfer room overhead 
crane onto or against a loaded, sealed WP after removal of the collar from 
the WP collar removal machine 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.5.7.1.8 Collision or impact of the lifting collar removal machine and a loaded, sealed 
WP placed on a pallet positioned on the WP turntable 
A design or operational requirement is assumed to ensure that an impact or collision between the 
trunnion collar removal machine and a WP would not breach the WP (Assumption 5.1.3.10). 
6.3.5.7.1.9 Drop of a loaded, sealed WP and pallet from a main transfer room overhead 
crane onto the floor during transfer of the WP and pallet from the WP 
turntable to the WP transporter bedplate 
Section 6.3.1.8 includes this potential event. 
6.3.5.7.1.10 Drop of a loaded, sealed WP and pallet from a main transfer room overhead 
crane onto the WP transporter bedplate during transfer of the WP and pallet 
from the WP turntable to the WP transporter bedplate 
Section 6.3.1.8 includes the potential drop event. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21). 
6.3.5.7.1.11 Drop or collision of a loaded, sealed WP on a pallet from a main transfer 
room overhead crane onto or against a sharp object during transfer of the 
WP and pallet from the WP turntable to the WP transporter bedplate 
Section 6.3.1.8 includes the potential drop event. Crane-load collisions do not initiate 
Category 1 or Category 2 event sequences (Section 6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 309 April 2005 
6.3.5.7.1.12 Equipment drop or collision (including lifting yokes) onto or against a 
loaded, sealed WP in the WP transporter load area (including the process to 
move the WP from the trolley to the WP transporter) 
Operational requirements will prevent radiological releases due to this potential event 
(Assumption 5.1.3.3). 
6.3.5.7.1.13 Collision involving a WP transporter (holding the sealed WP on a pallet) and 
the doors between the main transfer room and the preparation room 
A design requirement will prevent radiological releases due to this potential event (Assumptions 
5.1.7.3 and 5.1.7.7). 
6.3.5.7.1.14 The doors between the main transfer room and the preparation room close 
on the WP transporter (holding the sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a transporter 
would not overturn the transporter or cause it to drop its load (Assumption 5.1.1.13). Because 
the transporter remains upright there is no threat to the integrity of the WP. 
6.3.5.7.1.15 Collision involving WP transporter (holding the sealed WP on a pallet) and 
the shield doors between the preparation room and the entrance vestibule 
A design requirement will prevent radiological releases due to this potential event (Assumptions 
5.1.7.3 and 5.1.7.7). 
6.3.5.7.1.16 Shield doors between the preparation room and the entrance vestibule close 
on the WP transporter (holding the sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a transporter 
would not overturn the transporter or cause it to drop its load (Assumption 5.1.1.13). Because 
the transporter remains upright there is no threat to the integrity of the WP. 
6.3.5.7.1.17 Collision involving WP transporter (holding the sealed WP on a pallet) and 
the doors between the entrance vestibule and the ambient air (outside) 
A design requirement will prevent radiological releases due to this potential event (Assumptions 
5.1.7.3 and 5.1.7.7). 
6.3.5.7.1.18 Doors between the entrance vestibule and the ambient air (outside) close on 
the WP transporter (holding the sealed WP on a pallet) 
A design requirement is assumed to ensure that closure of the shield doors onto a transporter 
would not overturn the transporter or cause it to drop its load (Assumption 5.1.1.13). Because 
the transporter remains upright there is no threat to the integrity of the WP.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 310 April 2005 
6.3.5.7.1.19 Derailment or collision of a WP transporter (holding the sealed WP on a 
pallet) in the main transfer room, preparation room, or entrance vestibule 
followed by a load tipover or fall 
A design requirement is assumed to ensure that a collision or derailment of the WP transporter 
would not cause a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). 
6.3.5.7.2 Chemical Contamination/Flooding 
6.3.5.7.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
Because this section considers SNF contained in a sealed WP only (BSC 2005 [DIRS 171428], 
Section 6.6.4.7), this potential event will not occur unless an event sequence leads to exposure of 
SNF to air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to 
air. The consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.5.7.3 Explosion/Implosion 
6.3.5.7.3.1 Hydraulic system (or other pneumatic or pressurized system) missile due to a 
fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.5.7.3.2 Hydrogen explosion involving batteries on a trolley. 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.7.4 Fire, Thermal 
6.3.5.7.4.1 Electrical fire associated with the equipment in the WP transporter load area 
of the main transfer room, including the WP collar removal machine, the 
tilting machine, and the WP turntable 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.7.4.2 Electrical fire associated with the main transfer room overhead cranes 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 311 April 2005 
6.3.5.7.4.3 Electrical fire associated with equipment on the WP transporter, including 
motors to extend the WP transporter bedplate 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.7.4.4 Electrical fire associated with the WP transporter locomotive 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.7.4.5 Fire/explosion (battery/electrical fire) associated with the WP closure 
transfer trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.7.4.6 Transient combustible fire in the main transfer room, preparation room, or 
the entrance vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.7.5 Radiation 
6.3.5.7.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.5.7.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.5.7.5.3 Inadvertent opening of the main transfer room shield door, leading to a 
worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.5.7.5.4 Inadvertent opening of the WP transporter shielded enclosure doors, leading 
to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 312 April 2005 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.5.7.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.5.7.6 Fissile 
6.3.5.7.6.1 Criticality associated with a trolley holding a sealed WP derailment followed 
by a load tipover or fall and rearrangement of the WP internals 
A design requirement is assumed to ensure that the trolley will not derail or allow the unsealed 
WP to fall off the trolley (Assumption 5.1.1.36). Because the WP remains upright, there is no 
mechanism for reconfiguration of internals and, therefore, no criticality. 
6.3.5.7.6.2 Criticality associated with a drop, slapdown, or collision of a sealed WP and 
a rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). 
6.3.5.7.6.3 Criticality associated with a WP transporter derailment followed by a load 
tipover or fall and rearrangement of the WP internals 
A design requirement is assumed to ensure that a derailment of the WP transporter would not 
cause a WP breach (Assumptions 5.1.7.3 and 5.1.7.7). Another design requirement is assumed 
to preclude criticality in sealed WPs (Assumption 5.1.3.1). 
6.3.5.8 FHF Main Transfer Room, Preparation Room, Entrance Vestibule (Loaded 
MSC Removal) 
6.3.5.8.1 Collision/Crushing 
6.3.5.8.1.1 Impact due to horizontal movement of a loaded MSC by the main transfer 
room overhead crane before it is fully removed from the canister transfer 
station 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.5.8.1.2 Collision of a loaded MSC from the main transfer room overhead crane with 
the canister transfer station 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 313 April 2005 
6.3.5.8.1.3 Drop of an MSC inner or outer lid (as applicable) from the fuel transfer 
room overhead crane onto the loaded MSC in the fuel transfer bay or main 
transfer room (as applicable) 
The frequency and consequences of the drop of an outer lid are bounded by those of the 
Category 2 lid-drop event sequence discussed in Section 6.3.1.2. The frequency is bounded 
because the bounding event applies to WPs, MSCs, and transportation casks, but this event 
applies only to MSCs. The consequences are bounded because the contents of the MSC are 
protected by the inner lid, whereas no lids are in place for the bounding event. The material at 
risk is 5 HLW canisters. An operational requirement is assumed to ensure that the lid drop will 
not breach a DOE SNF canister inside (Assumption 5.1.1.44). 
The drop of an inner lid is included in Section 6.3.1.2. 
6.3.5.8.1.4 Drop or collision of the transfer port plug from the fuel transfer room 
overhead crane onto or against the inner lid or outer lid of a loaded MSC (as 
applicable) in the fuel transfer bay 
A design requirement to consider 2-over-1 event sequences will prevent initiation of an event 
sequence as a result of this potential event (Assumption 5.1.1.37). 
6.3.5.8.1.5 Drop of an MSC inner or outer lid (as applicable) from the main transfer 
room overhead crane onto the loaded MSC in the canister transfer station 
This potential event is covered by the analysis in Section 6.3.1.2. 
6.3.5.8.1.6 Collision of a mobile elevated platform with a loaded MSC during docking 
ring removal activities associated with the MSC 
Operational requirements are assumed to ensure that the mobile elevated platform will not be 
operated in a manner that could breach an MSC (Assumption 5.1.1.41). 
6.3.5.8.1.7 Collision of a trolley holding a loaded MSC on a pedestal with the shield 
doors separating the fuel transfer bay and the main transfer room 
Trolley collisions are covered in Section 6.3.1.22. 
6.3.5.8.1.8 Closure of the shield doors separating the fuel transfer bay and the main 
transfer room onto the trolley holding a loaded MSC on a pedestal 
A design requirement is assumed to ensure that closure of shield doors onto a trolley would not 
overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright there is no threat to the integrity of the cask. 
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 314 April 2005 
6.3.5.8.1.9 Drop or collision of tools or equipment (including the outer lid-lifting fixture, 
inner lid-lifting fixture [as applicable], lid bolts, etc.) onto or against an MSC 
inner lid or outer lid (as applicable) during the MSC sealing process 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.5.8.1.10 Derailment of a trolley serving a fuel transfer bay or the import-export 
trolley holding a loaded MSC on a pedestal followed by a load tipover or fall 
A design requirement is assumed to ensure that the import-export trolley carrying an MSC will 
not derail or allow the MSC to fall off the trolley (Assumption 5.1.1.36). Because the trolley 
remains upright there is no threat to the integrity of the cask. 
6.3.5.8.1.11 Drop of a loaded MSC from the main transfer room overhead crane onto the 
floor during the MSC transfer from a pedestal staged on a trolley serving the 
fuel transfer bay or from the canister transfer station to the import-export 
trolley and pedestal 
The analysis presented in Section 6.3.1.1.2 includes this potential event. 
6.3.5.8.1.12 Drop of a loaded MSC from the main transfer room overhead crane onto the 
pedestal on a trolley during the MSC transfer from a pedestal staged on a 
transfer trolley serving the fuel transfer bay or from the canister transfer 
station to the import-export trolley and pedestal 
The analysis presented in Section 6.3.1.1.2 includes this potential event. 
6.3.5.8.1.13 Drop or collision of a loaded MSC from the main transfer room overhead 
crane onto or against a sharp object during the transfer from a pedestal 
staged on a transfer trolley serving the fuel transfer bay or from the canister 
transfer station to the import-export trolley and pedestal 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.8.1.14 Slapdown of a loaded MSC following a drop onto the edge of the pedestal or 
trolley or other object during the transfer from a pedestal staged on a 
transfer trolley serving the fuel transfer bay or from the canister transfer 
station to the import-export trolley and pedestal 
This potential event is covered by Section 6.3.1.1.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 315 April 2005 
6.3.5.8.1.15 Slapdown of a loaded MSC onto the floor, into a wall, or into nearby 
equipment following a drop from the main transfer room overhead crane 
onto the edge of the import-export trolley, pedestal, or other equipment 
during the lift and transfer of the MSC from the canister transfer station to 
the import-export trolley 
This potential event is covered by Section 6.3.1.1.2. 
6.3.5.8.1.16 Collision of the import-export trolley holding a loaded MSC on a pedestal 
with the shield doors separating the main transfer room and the preparation 
room or the preparation room and the entrance vestibule 
Trolley collisions are covered in Section 6.3.1.22. 
6.3.5.8.1.17 Closure of the shield doors separating main transfer room and the 
preparation room or the preparation room and the entrance vestibule onto 
the import-export trolley holding a loaded MSC on a pedestal 
A design requirement is assumed to ensure that closure of shield doors onto a trolley would not 
overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright there is no threat to the integrity of the cask. 
6.3.5.8.1.18 Drop or collision of equipment in the preparation room onto or against a 
loaded MSC on a pedestal on an import-export trolley 
Operational requirements will ensure that this potential event will not initiate an event sequence 
(Assumption 5.1.1.32). 
6.3.5.8.1.19 Drop of a loaded MSC from the entrance vestibule gantry crane onto the 
floor during the lifting of the loaded MSC off of the pedestal on the importexport 
trolley 
This potential event is covered by Section 6.3.1.1.2. 
6.3.5.8.1.20 Drop or collision of a loaded MSC from the entrance vestibule gantry crane 
onto or against a sharp object during the lifting of the loaded MSC off of the 
pedestal on the import-export trolley 
Design and operational requirements will ensure that load paths are kept free of puncture hazards 
(Assumption 5.1.1.40). Crane-load collisions do not initiate Category 1 or Category 2 event 
sequences (Section 6.3.1.21). 
6.3.5.8.1.21 Slapdown of a loaded, sealed MSC following a drop from the entrance 
vestibule gantry crane onto the edge of the pedestal, edge of the importexport 
trolley, or other equipment during the lifting of the loaded MSC off of 
the pedestal on the import-export trolley 
This potential event is covered by Section 6.3.1.1.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 316 April 2005 
6.3.5.8.1.22 Collision of the entrance vestibule gantry crane holding a loaded MSC with a 
forklift, mobile elevated platform, or other object in the entrance vestibule 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). Operational requirements are assumed to ensure that forklifts and mobile elevated 
platforms will not be operated in a manner that could breach or overturn a transportation cask 
(Assumption 5.1.1.41). 
6.3.5.8.1.23 Collision of the entrance vestibule gantry crane holding a loaded MSC with 
the entrance vestibule doors 
Crane-load collisions do not initiate Category 1 or Category 2 event sequences (Section 
6.3.1.21). 
6.3.5.8.1.24 The entrance vestibule doors close on the entrance vestibule gantry crane 
holding a loaded MSC 
A design requirement is assumed to ensure that closure of a door onto a trolley would not 
overturn the trolley or cause it to drop its load (Assumption 5.1.1.13). Because the trolley 
remains upright there is no threat to the integrity of the cask. 
6.3.5.8.2 Chemical Contamination/Flooding 
6.3.5.8.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures. 
Because this section considers SNF in sealed MSCs only (BSC 2005 [DIRS 171428], Section 
6.6.4.8), this potential event will not occur unless an event sequence leads to exposure of SNF to 
air. Oxidation of the fuel matrix is a possible outcome of an event that exposes SNF to air. The 
consequence analyses will account for the possibility of oxidation, if applicable. 
6.3.5.8.3 Explosion/Implosion 
6.3.5.8.3.1 MSC inerting system (or other pneumatic or pressurized system) missile due 
to a fractured nozzle/valve stem/pneumatic device 
An operational requirement is assumed to prevent initiation of an event sequence by this 
potential event (Assumption 5.1.1.5). 
6.3.5.8.3.2 Hydrogen explosion involving batteries on the import-export trolley 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 317 April 2005 
6.3.5.8.3.3 Hydrogen explosion involving batteries on a mobile elevated platform 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to cause a radiological release (Assumption 5.1.1.51). 
6.3.5.8.3.4 Explosion hazard associated with the cask purging system and the ignition of 
hydrogen that may have accumulated in the cask prior to MSC purging and 
inerting 
Precautions taken during the cask sampling and purging process will provide reasonable 
assurance that such hydrogen explosions will not occur (Assumption 5.1.1.58). 
6.3.5.8.4 Fire, Thermal 
6.3.5.8.4.1 Electrical fire associated with the main transfer room overhead crane, or the 
entrance vestibule gantry crane 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.8.4.2 Electrical fire associated with handling equipment or other equipment 
located in the main transfer room, the preparation room, or the entrance 
vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.8.4.3 Transient combustible fire in the main transfer room, preparation room, or 
the entrance vestibule 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.8.4.4 Intact or non-intact SNF overheating due to a loss of cooling resulting in 
excessive temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
This potential event is discussed in Section 6.3.1.26. 
6.3.5.8.4.5 Fire/explosion (battery/electrical fire) associated with the import-export 
trolley or the MSC trolley 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 318 April 2005 
6.3.5.8.4.6 Fire/explosion (battery/electrical fire) associated with a mobile elevated 
platform 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.5.8.5 Radiation 
6.3.5.8.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable. 
6.3.5.8.5.2 Damage or rupture of cask inerting system leading to a release of cask 
internal gases 
Exposure of workers to radiation as a result of this potential event will be managed as a normaloperations 
dose by procedures for monitoring radiation doses and assigning work, which ensure 
that workers do not receive excessive radiation doses. Although a rupture leading to a 
radiological release would be an abnormal occurrence, radiation protection programs will ensure 
that such an occurrence would not contribute significantly to the normal operations dose. See 
Section 7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.5.8.5.3 Expansion of gases in the MSC, leading to radiological release 
Thermal expansion of gases is to be expected as a part of normal operations. Resulting exposure 
of workers to radiation will be managed as a normal-operations dose by procedures for 
monitoring radiation doses and assigning work, which ensure that workers do not receive 
excessive radiation doses. See Section 7.4 for a list of potential events and conditions that are 
treated as normal operations. 
6.3.5.8.5.4 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.5.8.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 319 April 2005 
6.3.5.8.6 Fissile 
6.3.5.8.6.1 Criticality associated with an MSC trolley collision or trolley derailment 
followed by a load tipover or fall and a rearrangement of the MSC internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.5.8.6.2 Criticality associated with a drop or slapdown of a loaded MSC from an 
overhead crane and a rearrangement of cask internals 
A criticality in an MSC is not credible because a design requirement will ensure that MSCs 
remain subcritical even with the most reactive credible configuration of the fissile material and 
optimal moderation (Assumption 5.1.1.4). 
6.3.5.8.6.3 Criticality associated with the drop of heavy equipment onto an unsealed 
MSC and a rearrangement of the container internals 
Equipment drop onto an MSC will not lead to a criticality because MSCs must be subcritical 
even with the most reactive credible configuration of the fissile material and moderation to the 
most reactive credible extent (Assumption 5.1.1.4). 
6.3.5.9 FHF Main Transfer Room, Preparation Room, Entrance Vestibule (Empty 
Transportation Cask, MSC Removal) 
6.3.5.9.1 Collision/Crushing 
No potential event sequences have been identified that affect a waste form. 
6.3.5.9.2 Chemical Contamination/Flooding 
No potential event sequences have been identified that affect a waste form. 
6.3.5.9.3 Explosion/Implosion 
No potential event sequences have been identified that affect a waste form. 
6.3.5.9.4 Fire, Thermal 
No potential event sequences have been identified that affect a waste form. 
6.3.5.9.5 Radiation 
6.3.5.9.5.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 320 April 2005 
6.3.5.9.5.2 Loss of confinement zone due to ventilation system malfunction or other 
breach of a confinement barrier leading to a release of airborne radiation 
This potential event is covered in Section 6.3.1.25. 
6.3.5.9.6 Fissile 
No potential event sequences have been identified that affect a waste form. 
6.3.6 Surface and Subsurface Facilities: WP Subsurface Transport and Emplacement 
In this functional area, WPs seated horizontally on pallets are transported to the emplacement 
drifts in the underground repository on a rail-based transporter. An emplacement gantry meets 
the transporter at the mouth of the emplacement drift, lifts the WP and its pallet, and carries them 
to a disposal location within the appropriate drift. A further description of the operations in this 
area and a listing of the hazards and potential events is provided in Internal Hazards Analysis for 
License Application (BSC 2005 [DIRS 171428], Section 6.6.5). 
6.3.6.1 Collision/Crushing 
6.3.6.1.1 Collision involving the transport locomotive and the WP transporter (holding 
the sealed WP on a pallet) during coupling, prior to entering the North Portal 
The likelihood of a collision involving the locomotive and the WP transporter during coupling, 
prior to entering the North Portal, has not been estimated. Instead, the consequences of that 
event are discussed. The collision would occur at the low speed typically required for the 
coupling operation. Also, the collision would impact the transporter itself, rather than the WP. 
Therefore, the energy of the impact would mainly be absorbed by the transporter. At worst, the 
collision may cause the derailment of the transporter, which is investigated in Section 6.3.6.1.3. 
In that section, it is shown that a transporter derailment will not cause the breach of the 
transported WP. Therefore, the event analyzed in the present section will not initiate a Category 
1 or Category 2 event sequence. 
6.3.6.1.2 Derailment of a WP transporter outdoors, prior to entering the north ramp, 
followed by a load tipover or fall 
A distinction between a transporter derailment outdoors, prior to entering the North Portal, and a 
transporter derailment in the subsurface facilities is to be made only if the WP breaches, because 
in that case, the two events may result in different doses to workers and the public, due to the 
difference between the surface environment and the subsurface environment. However, a breach 
of the WP following a derailment is shown to be a Beyond Category 2 event sequence (Section 
6.3.6.1.3), which makes it unnecessary to distinguish these two kinds of derailment further.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 321 April 2005 
6.3.6.1.3 Derailment of a WP transporter while on the north ramp, in a main drift, or in 
an emplacement drift turnout, after passing through the North Portal, 
followed by a load tipover or fall 
Several initiating events, such as a seismic event, or an object located on the railway may 
conceivably result in the derailment of the WP transporter, including a tipover. 
The approach chosen to address derailment events is to mitigate their consequences so that no 
WP breach occurs. 
It is assumed that the transporter will transport the WP in a manner such that if a derailment 
occurs, the WP impact energy will be low enough to preclude a WP breach (Assumptions 5.1.7.3 
and 5.1.7.7). This can be done in part by controlling the speed of the transporter. For example, 
Assumption 5.1.7.3 indicates that the maximum speed of the transporter required to preclude a 
waste package breach in case of a transporter collision or derailment (excluding tipover) is 15 
mph. Alternatively, should a tipover occur, the fact that the transporter speed is controlled will 
help limit the severity of the consequences of a tipover. Transporter speed exceeding what is 
allowable corresponds to transporter runaway situations, investigated in Section 6.3.6.1.4, which 
are shown to be Beyond Category 2. In addition, the transporter may be designed to limit the 
height of a WP during transportation such that a drop results in an impact energy lower than the 
energy corresponding to a WP without trunnion free falling from its design basis drop height. 
In order to mitigate the consequences of a derailment, additional design requirements are 
assumed on the transporter, namely that the restraints used to immobilize the bedplate inside the 
shielded compartment of the transporter, and the mechanism for locking the doors of the shielded 
compartment withstand a credible derailment and the subsequent collision of the transporter 
without resulting in a Category 1 or Category 2 event sequence (Assumption 5.1.7.4). A credible 
derailment (or collision) is defined as a derailment (collision) that will occur at a speed less than 
or equal to the maximum allowable speed of the transporter. Limiting the speed of the 
transporter makes it possible to design restraints and door locking mechanisms that do not fail as 
a result of a derailment or collision. These additional design requirements will ensure that no 
ejection of the WP will occur. This will make it possible to control the severity of the potential 
impacts that a WP may undergo as a consequence of a derailment. 
Therefore, the failure of the WP is preventable, and the event analyzed in this section will not 
initiate a Category 1 or Category 2 event sequence. 
6.3.6.1.4 Runaway of a loaded WP transporter while proceeding down the north ramp 
The north ramp leads from the surface facilities to the underground facilities. It is the primary 
location considered for analyzing runaways because of its length and slope. However, a runaway 
can be defined as an uncontrolled descent in the repository and therefore it may also occur in 
other locations than on the north ramp. Therefore, the analysis of the runaway event performed 
in this section should be viewed as applying to other locations of the repository where an 
uncontrolled descent may occur. 
Based on results reported in Section 4.1.17, it is concluded that waste package transporter 
runaway events will not initiate any Category 1 or Category 2 event sequence.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 322 April 2005 
6.3.6.1.5 Collision involving a WP transporter (holding a sealed WP on a pallet) and 
other stationary or moving equipment 
Several events can be categorized as transporter collisions. Two main categories can be 
considered: 
(1) the object with which the transporter collides is stationary, or, 
(2) the object with which the transporter collides is in motion. 
The first category encompasses the objects that may block the railway, such as doors of the 
surface or subsurface facilities accidentally left closed, some piece of equipment inadvertently 
left on the railway, etc. The bounding situation that may result from this type of collision is the 
derailment of the transporter. This event is analyzed in Section 6.3.6.1.3, and shown to be 
Beyond Category 2. 
The second category varies according to the type of object that may impact the transporter. 
Impacts from rockfalls are investigated in Section 6.3.6.1.9. Tornado missiles are addressed in 
Section 6.2.7. Impacts of an aircraft crash are investigated in Section 6.2.1. The potential 
collision with the locomotive during coupling is analyzed in Section 6.3.6.1.1. Other vehicles 
could crash into the transporter, for example a surface vehicle. Based on Assumption 5.1.7.1, 
which ensures that vehicle crossings of the railway will be controlled, the potential for a surface 
vehicle to hit a transporter carrying the WP is minimized. Should somehow a surface vehicle 
lose control and impact the transporter, the collision would not impact the WP which is protected 
by the shielded compartment. Therefore, minimal kinetic energy of the impacting vehicle would 
be transferred to the WP. At worst, the collision may cause the derailment of the transporter, 
which is investigated in Section 6.3.6.1.3, and shown not to initiate a Category 1 or Category 2 
event sequence. 
6.3.6.1.6 Derailment of a WP transporter at the turnout drift switch, followed by a load 
tipover or fall 
Derailment events have been grouped together and are addressed in Section 6.3.6.1.3, where it is 
shown that they will not initiate a Category 1 or Category 2 event sequence. 
6.3.6.1.7 Collision involving a WP transporter (holding the sealed WP on a Pallet) and 
the emplacement access doors 
At worst, collisions may cause the derailment of the transporter, which is investigated in Section 
6.3.6.1.3. In that section, it is shown that no Category 1 or Category 2 event sequence will be 
initiated. 
6.3.6.1.8 Emplacement access doors close on the WP transporter (holding the sealed 
WP on a pallet) 
A design requirement is assumed to ensure that closure of the doors onto the WP transporter will 
not cause a tipover of the transporter or cause it to drop its load (Assumption 5.1.1.13).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 323 April 2005 
6.3.6.1.9 Rockfall onto a WP transporter while in the subsurface 
While in the subsurface, the WP transporter could be impacted by a rockfall. Because the WP is 
protected by the shielded compartment of the transporter, its structural integrity will be 
jeopardized only if the shielded compartment fails first because of the rockfall. 
The first step in making such a determination is to evaluate the sets of bounding credible 
rockfalls that may hit the shielded compartment of the transporter. In Bounding Characteristics 
of Credible Rockfalls of Preclosure Period (BSC 2004 [DIRS 168508, Sections 1 and 6.1), no 
credit is taken for the ground support, which is conservative because ground support helps 
prevent rockfalls. The bounding rockfalls that may impact the transporter are triggered by the 
most severe seismic event considered for the preclosure period, which has a mean annual 
probability of exceedance equal to 10-4 (BSC 2004 [DIRS 168508], Section 6.1). The total 
exposure time during which the transporter carrying the WP may be hit by a rockfall is 
calculated based on an average exposure time of 6 hours per WP (Assumption 5.1.7.5). 
A set of credible bounding rockfalls is defined as a rockfall set whose total mass is such that the 
probability of observing a heavier rockfall set impacting the shielded compartment of the 
transporter is less than 10-4 over the preclosure period. The bounding set mass is calculated 
based on the results of simulations that perform a static modeling of the key blocks forming in 
the non-emplacement drifts during the seismic event (BSC 2004 [DIRS 168508], Section 
4.1.2.2). The size and layout of the non-emplacement drifts modeled in these simulations 
conform to what is currently considered for the repository. A conservative total mass of 5.4 MT 
for the sets of credible bounding rockfalls is found, and the sets are determined to include one to 
25 rocks (BSC 2004 [DIRS 168508], Section 7). 
A structural analysis is then performed to determine if a credible bounding rock falling from the 
crown of the non-emplacement drifts and impacting the shielded compartment of the transporter 
can damage it in a manner sufficient as to jeopardize the structural integrity of the WP. The 
results of this analysis show that this is not the case (BSC 2004 [DIRS 168963], Section 7). 
Therefore, the event analyzed in the present section will not initiate a Category 1 or Category 2 
event sequence. 
6.3.6.1.10 Collision involving a WP transporter (holding the sealed WP on a pallet) and 
the emplacement transfer dock (while entering the dock) 
The likelihood of a collision involving the transporter and the emplacement drift transfer dock 
has not been estimated. Instead, the consequences of that event are discussed. The worst-case 
scenario resulting from the collision is a transporter derailment, which is investigated in Section 
6.3.6.1.3. In that section, it is shown that a transporter derailment will not cause the breach of 
the transported WP. Therefore, the event analyzed in the present section will not initiate a 
Category 1 or Category 2 event sequence. 
6.3.6.1.11 WP transporter doors close on the WP on a pallet 
The likelihood of a collision between the transporter shielded enclosure doors and the WP sitting 
on the pallet has not been estimated. Instead, a design requirement is assumed to ensure that 
closure of the doors onto the WP would not breach it or cause it to fall from the bedplate of the
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 324 April 2005 
transporter (Assumption 5.1.7.2). Therefore, the event analyzed in the present section will not 
initiate a Category 1 or Category 2 event sequence. 
6.3.6.1.12 WP rolls or slides out of a WP transporter on the surface (outdoors), in a 
ramp, in a main drift, or at the entrance of the emplacement drift 
The WP has a bedplate that can be rolled in and out of the shielded compartment. The WP with 
its emplacement pallet sits on that bedplate. The bedplate is rolled inside the shielded 
compartment and the shielded compartment doors are closed when the transporter carrying a WP 
is in motion. The potential causes for a bedplate rollout while the transporter carrying a WP is in 
motion are: (a) a collision and its associated worst-case scenario, namely a derailment, (b) a 
spurious actuation of the system controlling the opening of the shielded compartments doors 
and the bedplate rollout mechanism, or (c) an operator-induced actuation of these doors and of 
the rollout mechanism. Each of these causes is investigated in the following paragraphs. 
The consequences of a transporter derailment are examined in Section 6.3.6.1.3. In that section, 
it is indicated that the transporter includes design features specifically aimed at mitigating the 
effect of the derailment by keeping the WP inside the shielded compartment. Thus, no breach of 
the transported WP is anticipated. 
The approach chosen to address the spurious or operator-induced opening of the shielded 
compartments doors and actuation of the bedplate rollout mechanism is to preclude, by design, 
the actual opening and actuation from occurring (Section 5.1.7.6). A scoping calculation is 
performed in the following to show that this is a realistic and attainable objective. This 
calculation explores possible design solutions to make the bedplate rollout event incredible. 
These design solutions, however, are given solely for illustration purposes, and should not be 
viewed as solutions formally accepted for the emplacement system design, which is still subject 
to evolution. The calculation will be updated as needed to reflect the latest design information 
available. 
First, an estimate of the global frequency of initiation of the bedplate rollout event is calculated. 
The probability of the operator attempting to prematurely actuate the bedplate rollout mechanism 
while the transporter is still in motion is estimated at 0.01, based on Assumption 5.2.5.1. 
In comparison, the probability of a spurious actuation of the door opening and bedplate rollout 
mechanisms is much smaller. For scoping purposes, this actuation is considered to be triggered 
by a process switch, for which a spurious operation rate on the order of magnitude of 10-6 per 
hour is used, based on Assumption 5.2.5.2. Because the travel time of the transporter 
underground is a few hours, the probability of observing a spurious signal during transportation 
will be in the 10-6 to 10-5 order of magnitude and therefore, much smaller than the 0.01 
probability of human-induced actuation. 
In addition, for this scoping calculation, it is reasonable to consider that the initiating event of the 
event sequence, namely an untimely bedplate rollout actuation, is independent from the response 
of the safety features controlling the transporter operation. This can be done for example by 
taking advantage of the many embedded redundancies and independent controls that safety 
systems typically have. Because of this independence, only the human-induced actuation of the
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 325 April 2005 
rollout mechanism needs further consideration in the quantification of the initiating event. This 
is because such a human error has a far greater probability than a spurious signal from a 
defective component. 
With 11,184 WPs to be emplaced (Section 4.1.1), and accounting for a factor of conservatism of 
1.1 (Section 6.1.4), this results in 11,184  1.1  0.01 = 123.02 opportunities for operator error 
initiating a rollout event over the preclosure period. For the event sequence initiated by this 
rollout event to be categorized as Beyond Category 2, its probability must be lower than 10-4 
over the preclosure period (Section 6.1.1). Consequently, the design features aimed at 
preventing the bedplate rollout must have a combined probability of failure less than 
10-4/123.02 = 8.1  10-7. 
This reliability objective is realistic and can be achieved by a variety of design features. 
Specifically, the safety controls may be designed such that a bedplate rollout signal is not 
permitted to go through if the transporter is recognized as being in motion, by a speed transducer 
for example. The typical failure probability for a speed transducer on the transporter is in the 
10-5 order of magnitude (Assumption 5.2.5.3). Taking credit for multiple and diverse 
components used to monitor the speed of the transporter, the global probability of failure to have 
a transporter is in motion signal could be as low as the combination of independent failure 
probabilities, and therefore made smaller than 10-5 by several orders of magnitude. For example, 
the probability that two independent speed transducers with individual failure probability of 10-5 
fail simultaneously is 10-5  10-5 = 10-10. Of course, several other types of components intervene 
in the architecture of a computer-assisted control of transport operations, and therefore the 
definitive probability of failure to inhibit a rollout signal while the transporter is in motion 
cannot be evaluated at this time. However, a global failure probability meeting the 8.1  10-7 
threshold mentioned previously appears to be achievable. 
In conclusion, the event analyzed in the present section will not initiate a Category 1 or Category 
2 event sequence. 
6.3.6.1.13 WP and pallet drop from a WP emplacement gantry 
In this section, emphasis is put on the scenario where the drop occurs in the emplacement drift. 
In addition to that scenario, Sections 6.3.6.1.16 and 6.3.6.1.17 analyze the particular cases where 
the drops occur at the extremities of the emplacement drifts. 
The drop of a WP from the emplacement gantry is analyzed in a generalized event tree, shown in 
Section 6.3.1.24. It is determined that the corresponding event sequence can be categorized as 
Beyond Category 2. 
6.3.6.1.14 Derailment of a WP emplacement gantry holding a WP on a pallet, followed 
by a load drop (drop of the WP and pallet) 
In this section, emphasis is put on the scenario where the drop occurs in the emplacement drift. 
In addition to that scenario, Sections 6.3.6.1.16 and 6.3.6.1.17 analyze the particular cases where 
the drops occur at the extremities of the emplacement drifts.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 326 April 2005 
The probability of a gantry derailment resulting in a drop of a WP is embedded in the failure rate 
of 10-5 drop/transfer considered in Assumption 5.1.8.1. Thus, the drop of a WP from the 
emplacement gantry due to gantry derailment is included as a subset of WP drops analyzed in 
Section 6.3.6.1.13. It is shown in that section that the corresponding event sequence is Beyond 
Category 2. 
6.3.6.1.15 WP emplacement gantry carrying a WP collides with another WP in the drift 
The gantry carrying a WP to its position in the emplacement drift could overshoot the mark and 
collide with a WP that is already in place. This scenario is analyzed in a generalized event tree, 
shown in Section 6.3.1.23. It is determined that the corresponding event sequence can be 
categorized as Beyond Category 2. 
6.3.6.1.16 WP emplacement gantry carrying a WP travels to the end of the drift and 
drops off the end of the rails, falling to the ground below 
Conceivably, due for example to a human error, a failure of the data communication system, or a 
failure of the gantry control system, the emplacement gantry carrying the first WP to be 
emplaced in a drift could fail to stop at the appropriate emplacement location, travel to the end of 
the drift, drop off the end of the rails and fall to the drift floor. This scenario does not apply to 
the WPs subsequent to a first emplacement in the drift since the gantry would collide first with 
the already emplaced WP. This latter scenario was analyzed in Section 6.3.6.1.15 and shown not 
to cause a WP breach. 
It is assumed that design requirements will prevent this scenario from unfolding (Assumption 
5.1.8.3). This can be done by installing rail stops at the end of the drift. These stops would 
block the way for the gantry and prevent it from progressing further into the drift, and therefore 
forestall a gantry drop off the rails. This would prevent Category 1 or Category 2 event 
sequences. 
Alternatively, it is shown in the following that the potential event sequence could be rendered 
Beyond Category 2 by taking credit for the fault-detection features of the emplacement gantry. It 
is expected that the emplacement equipment will be capable of detecting several kinds of 
failures, such as data communication, drive, and control system failures, and that upon detection 
of a failure, the gantry will autonomously suspend its operation. Section 4.3.3 indicates that the 
emplacement equipment has the capability to identify the drift and location within the drift where 
the WP will be emplaced, and also that the emplacement equipment has the capability to 
determine its location and distance traveled within the emplacement drift. These features could 
be used by a protection signal to prevent the gantry from going too far in the drift. 
The reliability threshold required for such a protection signal is now evaluated. 
Of the causes that could propel the gantry too far in an emplacement drift, only the human error 
is considered further, for the same reasons as those presented in Section 6.3.6.1.12 for a 
comparable situation (namely an untimely bedplate rollout event). The probability of human 
failure is assumed to be 0.01 (Assumption 5.2.6.2).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 327 April 2005 
Based on Section 4.1.7, there are 96 emplacement drifts in the repository. This number is 
conservatively rounded up to 150 for this scoping calculation. Therefore, the average number of 
times that the operator may inadvertently order the gantry too far in the drift when emplacing the 
first WP is 150  0.01 = 1.5. For the corresponding event sequence to be categorized as Beyond 
Category 2, its probability must be lower than 10-4 over the preclosure period (Section 6.1.1). 
This can be achieved by using a protection signal with a probability of failure less than 
10-4/1.5 = 6.7  10-5. This reliability objective is attainable, based on the results of Section 
6.3.6.1.12. In that section, it was shown that a more stringent reliability objective for a 
comparable design feature aimed at preventing a premature transporter bedplate rollout was 
attainable. A means to achieve the reliability objective is to use independent and diversified 
instrumentation and control. 
In conclusion, the event analyzed in the present section will not initiate a Category 1 or Category 
2 event sequence. 
6.3.6.1.17 WP emplacement gantry holding a WP on a pallet rolls off the emplacement 
drift transfer dock and either falls onto the drift rails (or surrounding ground) 
or impacts the WP transporter (if the transporter has not been moved) 
The generalized event tree of Section 6.3.1.24 is well adapted to describe drop scenarios that 
occur in the emplacement drift itself, because the WP drop height is only controlled by the lift 
height of the emplacement gantry. In contrast, when the gantry carrying the WP is located on the 
emplacement drift transfer dock, the WP drop height varies, depending on whether the 
transporter with its bedplate rolled out is present or not. If the transporter is present with its 
bedplate rolled out, the situation is comparable to when the gantry is in the emplacement drift. If 
the bedplate has been retracted or if the transporter has left the dock, the drop height of the WP 
will be higher than in the emplacement drift. The drop height of the WP may be reduced by 
having an emplacement drift transfer dock with raised floor. However, this may not be sufficient 
to meet the allowable WP drop heights outlined in Section 5.1.3.8. In the following, it is shown 
that it is possible to maintain the WP drop height within its design limits by use of protection 
features that meet the requirements outlined in Assumptions 5.1.8.1, 5.1.8.3, and 5.1.8.10. Two 
scenarios that result in a WP drop on the drift rails (or surrounding ground) are analyzed. 
The first conceivable scenario involves the emplacement gantry dropping the WP after a 
premature retraction of the bedplate or a premature departure of the transporter (that is before the 
gantry has reached the emplacement drift transfer dock). 
A possible cause for a premature bedplate retraction or transporter departure is an operator 
failure to observe the procedure that governs transport operations. A probability of 0.01 is 
associated with that failure, based on Assumption 5.2.5.1. A spurious operation of the control 
system is also conceivable, but for the same reasons as those presented in Section 6.3.6.1.12, the 
corresponding frequency of occurrence will be much smaller than the frequency of occurrence of 
an operator error, which is therefore the only event considered further. 
With 11,184 WPs to be emplaced (Section 4.1.1), and accounting for a factor of conservatism of 
1.1 (Section 6.1.4), the number of transfers during which a premature bedplate retraction or
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 328 April 2005 
transporter departure could happen from operator error is therefore, over the preclosure period: 
11,184  1.1 10-2 = 123.02. 
This number is for normal operating conditions. Another possible scenario would be an 
abnormal situation, where, for example, the emplacement gantry carrying the WP is immobilized 
over the transporter, due to a malfunction or a derailment. In that situation, it is conceivable that 
the transporter would have to be removed in order for some repair equipment to be dispatched to 
the emplacement drift. However, that would be done only after ensuring that the WP could not 
fall from the gantry, or, alternatively, after implementing safety measures aimed at ensuring that 
a drop of the WP could not cause its breach. Thus, these abnormal operating conditions can be 
eliminated from consideration. 
Based on Assumption 5.1.8.1, the failure rate of the emplacement gantry is 10-5 per transfer. The 
probability of a WP drop on the transporter railway is therefore, over the preclosure period: 
123.02  10-5 = 1.2  10-3. This is above the Category 2 threshold of 10-4. 
Therefore, if a protection signal, such as an interlock, was used to prevent a premature bedplate 
retraction or transporter departure, and consequently make the drop event Beyond Category 2, its 
failure probability would have to be lower than 10-4/1.2  10-3 = 8.3  10-2, which is achievable, 
based on the results of Section 6.3.6.1.12. In that section, it was shown that a much more 
stringent reliability objective for a comparable interlock, aimed at preventing a premature 
transporter bedplate rollout, was attainable. 
The use of a protection signal for precluding a premature bedplate retraction or transporter 
departure is a possible way to realize the requirements of Assumptions 5.1.8.1 and 5.1.8.10. The 
requirement of Assumption 5.1.8.1 is that the drop rate of the gantry be less than or equal to 10-5 
drops per transfer. The requirement of Assumption 5.1.8.10 is that the conditional probability of 
having exceeded the WP lift height limit given that a drop has occurred be 10-4 or less. In the 
present scenario, the WP drop and having exceeded the lift height limits are two independent 
events. Therefore, the requirement of Assumption 5.1.8.10 can be restated as: ensuring (with a 
probability of failure equal to or less than 10-4) that the gantry will not be put in a situation where 
the WP drop height would exceed its allowable limit. This failure probability associated with 
that requirement is stringent enough to meet the 8.3  10-2 probability with a comfortable 
margin. 
Another conceivable scenario that may result in a WP with emplacement pallet drop on the drift 
rails (or surrounding ground) assumes that the transporter has left the emplacement drift transfer 
dock and that the gantry is on its way to emplace the WP. Because of a spurious signal, or 
alternatively an operator inadvertently selecting a wrong control from a control panel, the gantry 
is ordered back to the emplacement drift transfer dock. If no credit is taken for the control 
features of the emplacement system, this could lead to a situation where the gantry travels onto 
the emplacement drift transfer dock. Should this abnormal situation be accompanied with a 
derailment, a WP drop on the drift rails (or surrounding ground) may occur. Even if no 
derailment occurs, the gantry could travel to the end of the transfer dock rails and roll off. 
Based on Assumption 5.1.8.3, the scenario where the emplacement gantry rolls off the 
emplacement drift transfer dock rails can be precluded. This can be done by installing rail stops
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 329 April 2005 
at the end of the dock rails. More generally, the premature return of the gantry to the 
emplacement drift transfer docks could be precluded by taking credit for the fault-detection 
features of the emplacement gantry. It is expected that the emplacement equipment will be 
capable of detecting several kinds of failures that could affect the emplacement gantry, such as 
data communication or control system failures. Section 4.3.3 also indicates that the 
emplacement equipment is capable of determining its location and distance traveled within the 
emplacement drift. This feature could be used by a protection signal, such as an interlock for 
example, to prevent the gantry, carrying the WP and coming from the emplacement drift, from 
entering the emplacement drift transfer dock if the transporter is not present. The reliability 
threshold required from such a protection signal is now calculated. 
Of the causes that could initiate a return of the gantry carrying the WP to the emplacement drift 
transfer dock, only the human error, having a probability of 0.01 based on Section 5.2.6.1, is 
considered further. A premature return due to a spurious operation of the control system is also 
conceivable, but for the same reasons as those presented in Section 6.3.6.1.12, the corresponding 
frequency of occurrence will be much smaller than the frequency of occurrence of an operatorinduced 
return. 
With 11,184 WPs to be emplaced (Section 4.1.1), and accounting for a factor of conservatism of 
1.1 (Section 6.1.4), there are 11,184  1.1  0.01 = 123.02 transfers for which the operator may 
inadvertently order the gantry back to the emplacement drift transfer dock. For the 
corresponding event sequence to be categorized as Beyond Category 2, its probability must be 
lower than 10-4 over the preclosure period (Section 6.1.1). This can be achieved by using an 
interlock with a failure rate less than 10-4/123.02 = 8.1  10-7 per transfer. This is a reliability 
objective which is achievable, based on the results of Section 6.3.5.6.1.12. In this section, it was 
shown that the same reliability objective for a comparable interlock, aimed at preventing a 
premature transporter bedplate rollout, was attainable. A means to achieve the reliability 
objective is to use independent and diversified instrumentation and control. 
The use of a protection signal for precluding a premature return of the gantry to the emplacement 
drift transfer dock is a possible way to realize the requirements of Assumptions 5.1.8.1 and 
5.1.8.10. The requirement of Assumption 5.1.8.1 is that the drop rate of the gantry be less than 
or equal to 10-5 drops per transfer. The requirement of Assumption 5.1.8.10 is that the 
conditional probability of having exceeded the WP lift height limit given that a drop has 
occurred be 10-4 or less. When combined together, these two requirements are equivalent to 
making the rate of a WP drop from above the allowable heights less than or equal to 10-9 per 
transfer. This failure rate is stringent enough to meet the failure rate of 8.1  10-7 calculated 
above with a comfortable margin. 
The investigation performed above shows that achievable design solutions can be implemented 
to prevent a WP drop from the gantry from exceeding the drop height limits outlined in 
Assumption 5.1.3.8. 
As a consequence, the event analyzed in the present section will not initiate a Category 1 or 
Category 2 event sequence.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 330 April 2005 
6.3.6.1.18 Empty WP emplacement gantry rolls off the emplacement transfer dock and 
falls onto the WP transporter, impacting the WP on the pallet on the extended 
bedplate 
Once the WP transporter has docked the emplacement drift transfer dock and the bedplate has 
been rolled out, the gantry proceeds to the dock. The gantry has lift hooks that engage below the 
overhangs of the pallet and off-load it from the transporter bedplate. Should the gantry derail 
from the dock during this operation, it could fall onto the bedplate and impact the WP. 
Based on Assumption 5.1.8.6, a design requirement ensures that this scenario will not jeopardize 
the structural integrity of the WP. Therefore, this event will not initiate a Category 1 or Category 
2 event sequence. 
6.3.6.1.19 Collision of a WP emplacement gantry holding a WP on a pallet with a fallen 
rock, fallen ground support, or other object, followed by a load drop (drop of 
the WP and pallet) 
A collision of the gantry with an object in the emplacement drift could also impact the WP 
carried by the gantry. Of the objects voluminous enough to impact the WP, another WP or a 
fallen rock are the most likely candidates. A collision with another WP has been analyzed in 
Section 6.3.6.1.15, and shown not to cause a WP breach, mainly because of the low speed of the 
gantry. For the same reason, a collision with a fallen rock will not breach the WP. 
The collision of the gantry could also cause its derailment and subsequent WP with emplacement 
pallet drop. Such a drop was analyzed in Section 6.3.6.1.13 and shown not to cause the breach 
of the WP. 
Therefore, the event analyzed in the present section will not initiate a Category 1 or Category 2 
event sequence. 
6.3.6.1.20 Rockfall onto a WP 
To determine if the rockfalls that could occur in the emplacement drifts during the preclosure 
period have the potential to jeopardize the integrity of the WPs, the characteristics of the credible 
bounding rockfalls have been evaluated in Bounding Characteristics of Credible Rockfalls of 
Preclosure Period (BSC 2004 [DIRS 168508], Section 7). 
The approach chosen is similar to what was done for characterizing the rockfalls in the nonemplacement 
drifts (Section 6.3.6.1.9). For example, no credit is taken for the ground support 
(BSC 2004 [DIRS 168508], Section 6.1), which is conservative because ground support helps 
prevent rockfalls. Also, the credible bounding rockfalls are evaluated for the most severe 
seismic event of the preclosure period, which has a mean annual probability of exceedance equal 
to 10-4 (BSC 2004 [DIRS 168508], Sections 1 and 6.1). The size and layout of the modeled 
emplacement drifts conform to what is currently considered for the repository. 
One major difference between the approaches for addressing rockfalls in the non-emplacement 
drifts and rockfalls in the emplacement drifts is that the emplacement drift rockfalls evaluated are 
based on the results of simulations providing for a dynamic modeling of the key blocks (BSC
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 331 April 2005 
2004 [DIRS 168508], Section 4.1.2.1). Thus, these rockfalls can be characterized not only by 
their mass, as was the case for the non-emplacement drift rockfalls, but also by their velocity and 
more importantly their kinetic energy, which is the driving quantity in determining whether a 
WP will breach due to the rockfall impact. Another major difference is that a distinction is made 
between single rockfalls and multiple rockfalls. Single rockfalls designate those rockfalls that 
fall sufficiently apart from each other for their effects on the impacted WP to be independent 
from one another. Multiple rockfalls designate those rockfalls that fall sufficiently close to each 
other for their effects on the WP to combine together (BSC 2004 [DIRS 168508], Section 1). 
For single rockfalls, a conservative total kinetic energy of 1.2  105 joules is found (BSC 2004 
[DIRS 168508], Section 7). 
For multiple rockfalls, the most energetic configurations are found to be those that involve two 
rockfalls (BSC 2004 [DIRS 168508], Section 6.2.4.2). The credible bounding two-rockfall 
configuration has a total kinetic energy of 1.0  105 joules (BSC 2004 [DIRS 168508], 
Section 7). 
Based on these results, a calculation was performed to determine whether credible bounding 
rockfalls impacting a WP could jeopardize its integrity. The results, reported in BSC (2004 
[DIRS 167182]), Section 6), show that no WP failure is expected. 
Another potential scenario involving a rockfall on a WP is now investigated. The rockfall is 
assumed to occur while the transporter carrying the WP is docked at the entrance of the 
emplacement drift, with the bedplate rolled out. This scenario needs to be investigated because 
the potential drop height of the rockfalls is higher in the emplacement drift turnouts (whose 
height it 7 m, see Section 4.1.6) than in the emplacement drifts (whose height is 5.5 m, see 
Section 4.1.6). The work performed in Attachment II shows that the rockfalls resulting from that 
scenario will not be more severe than the bounding credible rockfalls pertaining to the 
emplacement drifts, as long as the average exposure time of a WP transiting from the rolled out 
bedplate to the entrance of the emplacement drift does not exceed 4 hours. It is assumed that an 
operating requirement will ensure that this exposure time is not exceeded (Assumption 5.1.8.2). 
Therefore, this rockfall scenario will not cause a WP breach. 
In conclusion, the rockfall scenarios analyzed in the present section will not initiate a Category 1 
or Category 2 event sequence. 
6.3.6.1.21 Rockfall onto a WP emplacement gantry holding a WP on a pallet 
The consequences of a rockfall onto a loaded emplacement gantry are bounded by those of a 
rockfall onto a WP. The reason for this is that the sturdy structure of the gantry protects the WP 
from a direct hit by the rockfall. The consequences of a rockfall onto the WP are analyzed in 
Section 6.3.6.1.20, and shown not to cause the breach of the WP. Therefore, the event 
considered in this section will not initiate a Category 1 or Category 2 event sequence. 
6.3.6.1.22 Ground support drop onto a WP 
In the emplacement drifts, the recommended ground support consists of 3 m long Super Swellex 
rock bolts, spaced at 1.25 m, and Bernold-type perforated sheets, made of stainless steel and
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 332 April 2005 
installed in a 240 arc around the drift periphery (Section 4.1.3). Because the ground support is 
affixed to the rock, its drop onto a WP most likely would not occur without rock blocks attached 
to it, except in the case of an improper installation. The ground support drop scenario that would 
have the most serious consequences for the WP is that of a severe seismic event, causing a 
rockfall with elements of ground support attached to the rock blocks. This scenario, however, is 
not significantly more severe than a rockfall in which the ground support is neglected. This is 
because the steel sheets are only 3 mm thick, and the rock bolts are made of circular steel tube 
with a diameter of around 5 cm and a thickness of 3 mm (Section 4.1.3). Therefore, the ground 
support contributes only marginally to the mass of the credible bounding rock blocks that could 
fall in the emplacement drifts. Thus, the drop of failed ground support components is not 
expected to result in more severe consequences for the WP than the rockfalls resulting from 
seismic events considered in the preclosure period. It was shown in Section 6.3.6.1.20 that these 
credible bounding rockfalls would not cause the failure of the WP. Consequently, the event 
analyzed in the present section will not initiate a Category 1 or Category 2 event sequence. 
6.3.6.1.23 Ground support drop onto a WP emplacement gantry holding a WP on a 
pallet 
The consequences of a ground support drop onto a loaded emplacement gantry are bounded by 
those of a ground support drop onto a WP. The reason for this is that the sturdy structure of the 
gantry protects the WP from a direct hit by the ground support. The consequences of a ground 
support drop onto the WP are analyzed in Section 6.3.6.1.22, and are shown not to cause the 
breach of the WP. Therefore, the event considered in this section will not initiate a Category 1 or 
Category 2 event sequence. 
6.3.6.1.24 Runaway WP transporter in an access main and a collision with the barrier 
isolating the development side of the repository from the emplacement side of 
the repository 
Runaway events have been analyzed in Section 6.3.6.1.4, independently of their location of 
occurrence. In that section, it was shown that design features can render the initiation of a 
runaway event Beyond Category 2. 
Therefore, the event considered in this section will not initiate a Category 1 or Category 2 event 
sequence. 
6.3.6.2 Chemical Contamination/Flooding 
6.3.6.2.1 Flooding from a water pipe break originating on the development side of the 
repository 
Flooding of an emplacement drift is not expected to occur after the WPs are emplaced. Flooding 
is considered as a potential event in the drifts that are being excavated, and other subsurface 
areas of the repository, mainly because final decisions on the equipment, methods, and 
procedures to be used during the excavation phase have not been made. As a consequence, it is 
too early to preclude the use of water pipes for fire mitigation in some subsurface areas of the 
repository.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 333 April 2005 
As a cautionary remark, it should be noted that the word flooding is employed for consistency 
with Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], Section 
6.6.5). It suggests that the amount of water that could be used during the excavation phase could 
be high enough to cause flooding. In reality, the amounts of water used would be small, and a 
water pipe break could not lead to a flood in the subsurface facilities. 
No water pipes will be present in the drifts ready to receive WPs. Also, the underground layout 
of the repository is designed to ensure that water drainage is not towards the emplacement drifts 
(BSC 2003 [DIRS 165572], Section 7.2.5). Consequently, even if a water pipe break were to 
occur in the subsurface areas, the water drainage would lead away from the emplacement drifts. 
Thus, flooding will not initiate a Category 1 or Category 2 event sequence. 
6.3.6.2.2 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
or during off-normal condition (e.g., during a failure of the emplacement 
ventilation system) 
Oxidation of the waste form in subsurface during the preclosure period is Beyond Category 2 
because WPs are inerted and sealed before their transfer to the subsurface facility and because 
breach of the WP during the transfer and emplacement operations is Beyond Category 2 (Section 
6.3.6). 
6.3.6.3 Explosion/Implosion 
6.3.6.3.1 Hydrogen explosion involving batteries on the transport locomotive 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51). 
6.3.6.3.2 Hydrogen explosion involving batteries on the WP emplacement gantry 
The waste is protected by casks or WPs while in the presence of batteries for heavy equipment. 
The magnitude of a potential hydrogen explosion involving batteries for heavy equipment will be 
insufficient to initiate an event sequence (Assumption 5.1.1.51). 
6.3.6.4 Fire, Thermal 
6.3.6.4.1 Electrical fire associated with the transport locomotive 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.6.4.2 Fire/explosion (battery/electrical fire) associated with the transport locomotive 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9)
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 334 April 2005 
6.3.6.4.3 Fire/explosion (battery/electrical fire) associated with the WP emplacement 
gantry 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9) 
6.3.6.4.4 Electrical fire associated with equipment on the WP transporter, including 
motors to extend the WP transporter bedplate 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.6.4.5 Electrical fire associated with the WP emplacement gantry or other 
subsurface equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.6.4.6 WP overheating in the WP transporter due to solar insolation while stalled or 
stopped outdoors during transit from a surface facility to the Subsurface 
Facility 
Preliminary results of a calculation evaluating the maximum temperature reached by the WP 
show that the WP surface would not reach 200C (BSC 2004 [DIRS 171457], Table 3]. Results 
of structural calculations, reported in BSC (2004 [DIRS 169766], Section 7.1.1.2.5) show that at 
a temperature of 400F (204C), the waste package resting on an emplacement pallet maintains 
its structural integrity. As a consequence, the WP will not lose its structural integrity and this 
event will not initiate a Category 1 or Category 2 event sequence. 
6.3.6.4.7 Extended loss of the subsurface ventilation system 
This event has been analyzed in Section 6.2.4.7.1.7 and shown not to lead to a Category 1 or 
Category 2 event sequence. 
6.3.6.5 Radiation 
6.3.6.5.1 Radiation exposure of facility worker and/or the offsite public 
Exposure of workers and/or public to radiation is a hazard for the potential event sequences 
considered in the present analysis. The consequence analysis will evaluate this hazard for event 
sequences and normal operations, as applicable. 
6.3.6.5.2 Early WP failure while in the subsurface during the preclosure period and a 
resultant release of radioactive material 
Manufacturing defects that could affect a WP and potentially lead to its early failure have been 
considered (BSC 2004 [DIRS 170024]). An early failure is defined as a through-wall 
penetration occurring at a time earlier than would be predicted by mechanistic degradation
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 335 April 2005 
models for a defect-free WP (BSC 2004 [DIRS 170024], Section 1). The report cited identifies 
two major types of defects. The first type is the presence of weld flaws in the closure welds. 
The second type involves several fabrication defects, among which the improper heat treatment 
of the outer barrier is the dominant one in terms of probability of occurrence (BSC 2004 [DIRS 
170024], Section 7). The report concludes that despite their low probability of occurrence, these 
two types of defects could jeopardize the long-term integrity of the outer barrier of the WP. 
However, the report also indicates that a defective WP failure occurs only after degradation 
mechanisms take place, which may happen hundreds of years after emplacement in the 
repository (BSC 2004 [DIRS 170024], Section 7). Thus, it is anticipated that no significant 
degradation of a defective WP will take place during the 100-year preclosure period. 
In conclusion, the event analyzed in the present section will not initiate a Category 1 or Category 
2 event sequence. 
6.3.6.5.3 Release of activated air and dust to the environment 
This event is part of normal operations. Resulting exposure of workers to radiation will be 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. See Section 
7.4 for a list of potential events and conditions that are treated as normal operations. 
6.3.6.5.4 Inadvertent opening of the WP transporter shielded enclosure doors, leading 
to a worker exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers to radiation will be limited by design 
features and operating procedures that ensure that such events are not Category 1 (Assumption 
5.1.1.57). 
6.3.6.5.5 Radiation-induced damage to a facility SSC 
Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization as explained in Section 6.3.2.5.2. 
6.3.6.5.6 Inadvertent opening of the emplacement access doors, leading to a worker 
exposure 
This potential event could expose workers to radiation, but would not expose the public. The 
frequency of inadvertent actions that expose workers (but not the public) to radiation will be 
limited by design features and operating procedures that ensure that such events are not 
Category 1 (Assumption 5.1.1.57).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 336 April 2005 
6.3.6.6 Fissile 
6.3.6.6.1 Criticality associated with a drop or collision of a WP and a rearrangement of 
the container internals 
WPs and the facilities for handling them are designed such that drops, collisions, and other 
handling impacts that may affect the containers cannot lead to a nuclear criticality (Assumption 
5.1.3.1). Also, once the WPs are emplaced in the repository, they are not expected to breach 
during the preclosure period (see Section 6.3.6). This precludes criticality events prompted by 
the possible presence of water. 
6.3.7 Surface Facilities: SNF Aging System 
All of the internal events for the SNF Aging System are Beyond Category 2 (Section 4.1.11). 
6.3.8 Subsurface Facilities: Construction Hazards 
A description of the operations in this area and a listing of the hazards and potential events is 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.7). 
6.3.8.1 Fire, Thermal 
6.3.8.1.1 Diesel fire/explosion associated with subsurface development equipment 
resulting in damage to the subsurface isolation barriers 
Construction activities are sufficiently isolated from emplacement activities that a diesel fire or 
explosion associated with development equipment will not initiate an event sequence 
(Assumption 5.1.10.1). 
6.3.8.1.2 Electrical fire associated with subsurface development equipment or other 
equipment resulting in damage to the subsurface isolation barriers 
Construction activities are sufficiently isolated from emplacement activities that an electrical fire 
associated with development equipment will not initiate an event sequence (Assumption 
5.1.10.1). 
6.3.8.1.3 Transient combustible fire in the development side of the subsurface facilities 
resulting in damage to the subsurface isolation barriers 
Construction activities are sufficiently isolated from emplacement activities that a fire associated 
with transient combustibles on the development side will not initiate an event sequence 
(Assumption 5.1.10.1).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 337 April 2005 
6.3.8.2 Flooding 
6.3.8.2.1 Flooding from a pipe break originating on the development side of the 
repository 
Construction activities are sufficiently isolated from emplacement activities that flooding from a 
pipe break on the development side will not initiate an event sequence (Assumption 5.1.10.1). 
See Section 6.3.6.2 for further discussion.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 338 April 2005 
6.3.9 Surface Facilities: Construction Hazards 
Construction of surface facilities will be done in stages so that transfer and emplacement 
operations can begin before construction of surface facilities is complete. Therefore, separation 
must be maintained between waste transfer and emplacement activities and activities that support 
surface construction or subsurface excavation. The erection of temporary physical barriers to 
separate construction activities from the rest of the site activities is an effective and common 
method of reducing, if not eliminating, interactions. In addition, administrative controls provide 
a means of preventing interactions. A further description of the operations in this area and a 
listing of the hazards and potential events is provided in Internal Hazards Analysis for License 
Application (BSC 2005 [DIRS 171428], Section 6.6.8). 
6.3.9.1 Collision/Crushing 
6.3.9.1.1 Impacts on a loaded transportation cask, a loaded MSC, or a loaded WP as a 
result of construction operations 
Impacts on a loaded transportation cask, a loaded MSC, a loaded shuttle cask, or a loaded WP 
will be minimized by isolation of construction activities from emplacement activities 
(Assumption 5.1.10.1). 
6.3.9.2 Fire, Thermal 
6.3.9.2.1 Diesel fire/explosion associated with construction equipment 
Operating requirements will ensure that construction operations are sufficiently isolated from 
surface and subsurface repository operations to preclude proximity interactions with waste 
receipt, handling, emplacement, or retrieval operations (Assumption 5.1.10.1). 
6.3.9.2.2 Electrical fire associated with construction equipment or other equipment 
Construction activities are sufficiently isolated from emplacement activities that an electrical fire 
associated with development equipment will not initiate an event sequence (Assumption 
5.1.10.1). This event would be a Beyond Category 2 event. 
6.3.9.2.3 Transient combustible fire 
Construction activities are sufficiently isolated from emplacement activities that a transient 
combustible fire associated with construction activities will not initiate an event sequence 
(Assumption 5.1.10.1). This event would be a Beyond Category 2 event. 
6.3.9.3 Radiation 
6.3.9.3.1 Radiation exposure of a facility worker and/or the offsite public 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 339 April 2005 
6.3.9.4 Fissile 
6.3.9.4.1 Criticality associated with an impact on a loaded transportation cask, a loaded 
MSC, or a loaded WP and a rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals, 
proximity of other sealed waste packages, and without credit for burnup) cannot lead to a nuclear 
criticality (Assumption 5.1.3.1). Design requirements and waste acceptance criteria will ensure 
that transportation casks and MSCs remain subcritical even with reconfiguration of the fissile 
material due to a drop and optimal moderation (Assumption 5.1.1.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 340 April 2005 
6.3.10 Subsurface Facility: Drip Shield Installation 
A description of the associated operations and a listing of the hazards and potential events is 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.9). 
6.3.10.1 Collision/Crushing 
6.3.10.1.1 Derailment of a drip shield emplacement gantry carrying a drip shield, 
followed by a load drop (drop of the drip shield); the drip shield and/or the 
gantry impacts a WP or several WPs 
The drip shield and its emplacement gantry are designed to straddle the waste package during 
installation (Section 4.1.16). Therefore, if a derailment were to occur and the drip shield were to 
be dropped, the impact would mainly be between the drip shield and the ground. A contact 
between the drip shield (or the gantry) and the waste package, if any, would occur laterally and 
could only transfer a small fraction of the impact energy to the waste package. This energy 
would be dissipated through friction and would not be sufficient to cause a waste package 
breach. Thus, this event will not initiate an event sequence. 
6.3.10.1.2 Drip shield emplacement gantry carrying a drip shield collides with a WP or 
WPs due to gantry failure 
This event would lead to the same consequences as that of Section 6.3.10.1.1 and therefore 
would not initiate an event sequence. 
6.3.10.1.3 Collision of a drip shield emplacement gantry holding a drip shield with a 
fallen rock, fallen ground support, or other object, followed by a load drop 
(drop of the drip shield) onto a WP or WPs 
This event would lead to the same consequences as that of Section 6.3.10.1.1 and therefore 
would not initiate an event sequence. 
6.3.10.1.4 Rockfall onto a drip shield emplacement gantry carrying a drip shield, leading 
to gantry damage or failure and impact of the rock or drip shield with a WP 
Rockfall onto a WP is discussed in Section 6.3.6.1.20. For this potential event, the drip shield 
emplacement gantry protects the WP from rockfall by absorbing much of the impact energy. 
6.3.10.1.5 Rockfall onto a WP 
Rockfall onto a WP is discussed in Section 6.3.6.1.20. 
6.3.10.1.6 Ground support drop onto a WP 
Drop of ground support onto a WP is discussed in Section 6.3.6.1.22.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 341 April 2005 
6.3.10.1.7 Ground support drop onto a drip shield emplacement gantry carrying a drip 
shield, leading to gantry damage or failure and impact of the ground support 
or drip shield with a WP 
Drop of ground support onto a WP is discussed in Section 6.3.6.1.22. For this potential event, 
the drip shield emplacement gantry protects the WP from dropped ground support components 
by absorbing much of the impact energy. 
6.3.10.2 Chemical Contamination/Flooding 
6.3.10.2.1 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
or during off-normal conditions (e.g., during a failure of the emplacement 
ventilation subsystem) 
There are no Category 1 or Category 2 event sequences underground. Therefore, SNF will not 
be exposed to air and SNF oxidation will not occur. 
6.3.10.3 Fire, Thermal 
6.3.10.3.1 Electrical fire associated with the drip shield emplacement gantry or other 
subsurface equipment 
A separate analysis identifies design and operational requirements to ensure that event sequences 
potentially initiated by fire are Beyond Category 2 (Section 4.1.9). 
6.3.10.3.2 Loss of the subsurface ventilation system 
This event has been analyzed in Section 6.2.4.7.1.7 and shown not to lead to a Category 1 or 
Category 2 event sequence. 
6.3.10.4 Radiation 
6.3.10.4.1 Early WP failure while in the subsurface during the preclosure period and a 
resultant release of radioactive material 
Early failure of the WP is discussed in Section 6.3.6.5.2. 
6.3.10.4.2 Release of activated air and dust to the environment 
Activated air and dust will be released continuously into the environment by the subsurface 
ventilation system. Therefore, this event is a part of normal operations (see Section 7.4).
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 342 April 2005 
6.3.10.5 Fissile 
6.3.10.5.1 Criticality associated with an impact or collision with a WP and a 
rearrangement of the container internals 
A design requirement will ensure that WPs are designed such that drops, collisions, and other 
handling impacts within their design bases (allowing for rearrangement of container internals and 
without credit for burnup) cannot lead to a nuclear criticality (Assumption 5.1.3.1). The 
requirement is achievable because moderator is excluded by maintaining the integrity of the WP.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 343 April 2005 
6.3.11 Subsurface Facility: Retrieval 
A description of the operations associated with retrieval of a limited number of WPs is provided 
in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], Section 
6.6.10). Permanent retrieval is beyond the scope of the present analysis, as stated in Section 1. 
The applicability of generic events and the potential events associated with retrieval operations 
for a limited number of WPs are the same as those for the emplacement operations because one 
process is the reverse of the other. The generic events associated with WP subsurface transport 
and emplacement are described in Section 6.3.6. If additional surface facilities are required for 
retrieval activities, the hazards associated with these facilities will be examined in a future 
hazards analysis.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 344 April 2005 
6.3.12 Surface Facilities: Site-Generated Radiological Waste Disposal 
A description of the associated operations and a listing of the hazards and potential events is 
provided in Internal Hazards Analysis for License Application (BSC 2005 [DIRS 171428], 
Section 6.6.11). 
6.3.12.1 Collision/Crushing 
6.3.12.1.1 Drop of a heavy load onto a tank, piping, or a container containing liquid or 
solid radioactive waste 
Minor radioactive releases are expected as a part of normal operations. Resulting exposure of 
workers to radiation will be managed as a normal-operations dose by procedures for monitoring 
radiation doses and assigning work, which ensure that workers do not receive excessive radiation 
doses. See Section 7.4 for a list of potential events and conditions that are treated as normal 
operations. Resulting exposure of the public at the site boundary will be insignificant. 
6.3.12.1.2 Drop of a container or drum containing solid low-level radioactive waste 
(LLW) 
Minor radioactive releases are expected as a part of normal operations. Resulting exposure of 
workers to radiation will be managed as a normal-operations dose by procedures for monitoring 
radiation doses and assigning work, which ensure that workers do not receive excessive radiation 
doses. See Section 7.4 for a list of potential events and conditions that are treated as normal 
operations. Resulting exposure of the public at the site boundary will be insignificant. 
6.3.12.2 Chemical Contamination/Flooding 
6.3.12.2.1 Drop of a container or drum containing liquid LLW 
Minor radioactive releases are expected as a part of normal operations. Resulting exposure of 
workers to radiation will be managed as a normal-operations dose by procedures for monitoring 
radiation doses and assigning work, which ensure that workers do not receive excessive radiation 
doses. See Section 7.4 for a list of potential events and conditions that are treated as normal 
operations. Resulting exposure of the public at the site boundary will be insignificant. 
6.3.12.2.2 Release of radioactive gas from the gas filtration systems or cavity gas 
sampling systems, WP evacuating and inerting systems, cask evacuating and 
inerting systems, or the system involved with the cooling of casks prior to 
immersion in the DTF remediation area pool 
Release of gases from these operations is to be expected as a part of normal operations. 
Resulting exposure of workers to radiation will be managed as a normal-operations dose by 
procedures for monitoring radiation doses and assigning work, which ensure that workers do not 
receive excessive radiation doses. See Section 7.4 for a list of potential events and conditions 
that are treated as normal operations. Resulting exposure of the public at the site boundary will 
be insignificant.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 345 April 2005 
6.3.12.3 Fire 
6.3.12.3.1 Transient combustible fire in areas where dry, flammable low-level 
radioactive waste is stored 
Operating requirements will provide a control program limiting the presence of combustible and 
flammable materials in areas where dry, flammable low level radioactive waste is stored. These 
requirements will ensure that a fire that does occur in these areas will not be of significant 
intensity, duration, or magnitude to initiate an event sequence (Assumption 5.1.1.6). Such a 
program will limit a fire sequence to Beyond Category 2. 
6.3.12.4 Radiation 
6.3.12.4.1 Radiation exposure of a facility worker 
Exposure of workers or the offsite public to radiation is a hazard for the potential event 
sequences considered in the present analysis. The consequence analysis will evaluate this hazard 
for event sequences and normal operations, as applicable.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 346 April 2005 
7 RESULTS 
The present analysis is based on the design of repository facilities described in Internal Hazards 
Analysis for License Application (BSC 2005 [DIRS 171428]). See Attachment III for a tabular 
compilation of results. 
7.1 EXTERNAL EVENT SEQUENCES 
A Category 2 seismic event sequence is identified in Section 6.2.6. To avoid including releases 
from HLW canisters in the Category 2 seismic event sequence, the HLW canisters are hereby 
upgraded to DBGM-2. The bounding material at risk for the Category 2 seismic event sequence 
is 
 Sixteen BWR or nine PWR assemblies breached underwater in the remediation pool 
 Six BWR or PWR assemblies breached in dry transfer cells in DTF and FHF 
 Accumulated radioactive material in HEPA filters associated with the Surface Nuclear 
HVAC 
 Accumulated radioactive material in exhaust ducting and dampers associated with the 
Surface Nuclear HVAC. 
For other applicable external hazards, it has been shown in Section 6.2 that either 
 External initiating-event frequencies are Beyond Category 2, or 
 Features of the repository have been identified such that the external hazard will not 
initiate a Category 1 or Category 2 event sequence. 
Thus, there are no Category 1 or Category 2 external event sequences, with the exception of the 
Category 2 seismic event sequence described above. 
7.2 INTERNAL EVENT SEQUENCES 
7.2.1 Category 1 Internal Event Sequences 
The analysis in Section 6.3 identified two Category 1 internal event sequences (Section 6.3.1.3). 
They involve drops or collisions of bare CSNF assemblies. The numbers of assemblies affected 
and the annual frequencies of drops and collisions at the maximum rate of receipt for the 
repository are summarized in Table 51.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 347 April 2005 
Table 51. Category 1 Event Sequences 
Event 
Sequence 
Identifier Description 
Expected Number of 
Event Sequences 
Before Permanent 
Closure 
Annual Event 
Frequency for 
Consequence 
Analysis 
Bounding Material 
at Risk 
GET-03D Drop of a CSNF assembly in 
the DTF or FHF 
9.7 drops 0.5 drops/y 2 PWR or 2 BWR 
assemblies 
GET-03B Collision involving a CSNF 
assembly in the DTF or FHF 
9.7 collisions 0.5 collisions/y 1 PWR or 1 BWR 
assembly 
7.2.2 Combinations of Category 1 Internal Event Sequences 
Combinations of Category 1 event sequences that may occur within the same year are now 
investigated. This is done in view of the consequence analyses that will evaluate the radioactive 
releases of Category 1 event sequences. 
The probability distribution on the number of collisions of CSNF assemblies that may occur 
within the same year can be described with a Poisson distribution having a mean equal to 0.5 
collisions per year  1 year = 0.5 collisions. This yields the following probability values 
(rounded to two significant figures): probability of no collision within a year: 0.61; probability of 
one collision within a year: 0.30; probability of two collisions within a year: 0.08. 
The same values are found for the probability distribution on the number of drops of CSNF 
assemblies within a year, which can be described by a Poisson distribution having a mean equal 
to 0.5 drops. 
The probability values of combinations of drop and collision events, for up to two collisions or 
drops occurring within a same year, are shown in Table 52. The table also presents the total 
numbers of events (drops and collisions occurring within the same year), along with their 
corresponding probabilities. The probabilities associated with three or four events within a same 
year are not calculated because they involve drop and collision combinations that are not shown 
in the table (namely the events involving at least three drops or three collisions). The probability 
values are presented with two significant figures. 
Table 52. Collision and Drop Event Combinations and Probabilities 
Number of 
Collisions within 
the Same Year 
Number of 
Drops within the 
Same Year 
Probability of 
the Combination 
of Collision and 
Drop Events 
Total Number 
of Events 
(Drops plus 
Collisions) 
Probability 
of the Total 
Number of 
Events 
Cumulative 
Probability of the 
Total Number of 
Events 
0 0 0.37 0 0.37 0.37 
1 0 0.18 
0 1 0.18 1 0.37 0.74 
1 1 0.092 
2 0 0.046 
0 2 0.046 2 0.18 0.92 
2 1 0.023 
1 2 0.023 3 N/A N/A 
2 2 0.0057 4 N/A N/A
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 348 April 2005 
Table 52 is used to determine the combinations of Category 1 event sequences occurring within 
the same year to consider for consequence analyses. It is seen that the probability of observing 
no more than two Category 1 event sequences (CSNF assembly collisions or drops) within the 
same year is 0.92. Based on this high probability value, it is reasonable to eliminate from further 
consideration the combinations of Category 1 event sequences that involve at least three events 
(collisions or drops). Thus, the combinations of Category 1 event sequences to consider for 
consequence analyses are: 
1) Two drops occurring within the same year. Based on Table 51 this combination involves 
a total of 4 assemblies. 
2) Two collisions occurring within the same year. Based on Table 51, this combination 
involves a total of 2 assemblies. 
3) One drop and one collision within the same year. Based on Table 51, this combination 
involves a total of 3 assemblies. 
7.2.3 Category 2 Internal Event Sequences 
The Category 2 internal event sequences that were identified in Section 6.3 involve drops or 
collisions in the surface facilities resulting in radioactive releases from SNF, HLW, or naval 
SNF. A conservatively estimated number of occurrences over the life of the repository and the 
amount of material at risk were estimated for each of the Category 2 event sequences listed in 
Table 53. Some Category 2 event sequences, not listed in the table, were categorized by 
observing that the expected number of occurrences and the material at risk were bounded by one 
or more of the events listed in Table 53. 
Table 53. Category 2 Internal Event Sequences 
Internal 
Event 
Sequence 
Identifier 
Description of Internal Event 
Sequence 
Cross- 
Reference 
(Section 
Number) 
Expected 
Number of 
Occurrences 
Before 
Permanent 
Closure 
Bounding Material at 
Risk 
GET-01A Drop of a transportation or transfer 
cask without impact limiters in the 
TCRRF, DTF, CHF, or FHF 
6.3.1.1 5.7E-01 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister 
GET-02B Drop of inner lid of a transportation or 
transfer cask, MSC, or WP into a 
transportation cask, MSC, or WP in the 
DTF, CHF, or FHF 
6.3.1.2 5.7E-01 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister 
GET-03E Drop of a CSNF assembly during 
transfer in the DTF or FHF combined 
with HVAC failure 
6.3.1.3 9.7E-02 2 BWR or 2 PWR 
assemblies
Categorization of Event Sequences for License Application 
Table 53. Category 2 Event Sequences (Continued) 
000-00C-MGR0-00800-000-00B 349 April 2005 
Internal 
Event 
Sequence 
Identifier 
Description of Internal Event 
Sequence 
Cross- 
Reference 
(Section 
Number) 
Expected 
Number of 
Occurrences 
Before 
Permanent 
Closure 
Bounding Material at 
Risk 
GET-03C Collision involving a CSNF assembly 
during transfer in the DTF or FHF 
combined with HVAC failure 
6.3.1.3 9.7E-02 1 BWR or 1 PWR 
assembly 
GET-04B Drop or collision of handling equipment 
onto a CSNF assembly in the DTF or 
FHF 
6.3.1.4 9.7E-02 1 BWR or PWR 
assembly 
GET-05B Drop of a canister during transfer by 
crane in the CHF, DTF, or FHF 
6.3.1.5 5.7E-01 2 HLW, 1 naval, or 1 
DPC canister 
GET-06B Drop of handling equipment onto a 
canister in the CHF, DTF, or FHF 
6.3.1.6 5.7E-01 1 HLW, 1 naval, or 1 
DPC canister 
GET-07B Drop of an unsealed WP in the DTF, 
CHF, or FHF 
6.3.1.7 8.6E-02 44 BWR or 21 PWR 
assemblies, 1 naval 
canister, or 5 HLW 
canisters 
GET-09C Drop of a WP with a known closure 
defect in the CHF, DTF, or FHF 
6.3.1.9 2.6E-02 44 BWR assemblies, 
21 PWR assemblies, 
1 naval canister, or 
5 HLW canisters 
GET-10C Drop of a CSNF assembly during dry 
remediation activities in the DTF 
6.3.1.10 4.9E-01 2 BWR or 2 PWR 
assemblies 
GET-10B Collision involving a CSNF assembly 
during dry remediation activities in the 
DTF 
6.3.1.10 4.9E-01 1 BWR or 1 PWR 
assembly 
GET-11B Drop of a canister from a crane during 
WP remediation or dry remediation 
activities in the DTF 
6.3.1.11 5.7E-02 2 HLW, 1 naval, or 1 
DPC canister (74 BWR 
or 36 PWR 
assemblies) 
GET-12B Drop of CSNF assembly 
transfer/handling equipment onto 
CSNF assemblies in the DTF 
remediation pool 
6.3.1.12 4.9E-03 1 BWR or 1 PWR 
assembly
Categorization of Event Sequences for License Application 
Table 53. Category 2 Event Sequences (Continued) 
000-00C-MGR0-00800-000-00B 350 April 2005 
Internal 
Event 
Sequence 
Identifier 
Description of Internal Event 
Sequence 
Cross- 
Reference 
(Section 
Number) 
Expected 
Number of 
Occurrences 
Before 
Permanent 
Closure 
Bounding Material at 
Risk 
GET-13A Drop of a loaded transportation cask or 
MSC in the DTF wet remediation area 
6.3.1.13 1.1E-01 74 BWR or 36 PWR 
assemblies, 5 HLW 
canisters, or 1 naval 
canister 
GET-15C Drop of an empty or full canister for 
damaged CSNF assemblies (empty or 
full) onto or against a cask or basket in 
the DTF remediation pool 
6.3.1.15 4.9E-02 2 BWR or 2 PWR 
assemblies 
GET-15B Collision of an empty or full canister for 
damaged CSNF assemblies (empty or 
full) onto or against a cask or basket in 
the DTF remediation pool 
6.3.1.15 4.9E-02 1 BWR or 1 PWR 
assemblies 
GET-16C Drop of a CSNF assembly in the DTF 
remediation pool 
6.3.1.16 4.9E-01 2 BWR or 2 PWR 
assemblies 
GET-16B Collision involving a CSNF assembly 
in the DTF remediation pool 
6.3.1.16 4.9E-01 1 BWR or 1 PWR 
assemblies 
GET-17B Drop of a filled SNF basket from the 
spent fuel transfer machine onto the 
DTF remediation pool floor 
6.3.1.17 5.4E-02 16 BWR or 9 PWR 
assemblies 
GET-18B Drop of handling equipment into or 
against an opened WP filled with 
CSNF during dry remediation activities 
in the DTF 
6.3.1.18 4.9E-03 1 BWR or 1 PWR 
assembly 
GET-19B Drop of handling equipment into an 
open WP loaded with DOE canister or 
a naval canister during dry remediation 
activities in the DTF 
6.3.1.19 3.6E-02 1 HLW canister or 1 
naval canister 
GET-20B Drop of the severed DPC lid back onto 
the DPC in the DTF 
6.3.1.20 1.0E-01 74 BWR or 36 PWR 
assemblies 
7.2.4 Beyond Category 2 Internal Event Sequences 
The remaining potential events or event sequences have been found to have no potential for 
exposure of individuals to radiation or to be Beyond Category 2.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 351 April 2005 
7.3 PROPOSED REQUIREMENTS 
This analysis makes a number of assumptions that recommend design and operational 
requirements that have not yet been established (Section 5). These assumptions were used in the 
analysis to categorize event sequences. A subsequent nuclear safety basis report will formalize 
the recommended design requirements. 
7.4 POTENTIAL EVENTS CONSIDERED PART OF NORMAL OPERATIONS 
Some potential events that were identified in Internal Hazards Analysis for License Application 
(BSC 2005 [DIRS 171428], Section 6) are identified in the present analysis as a part of normal 
operations (Table 54). An additional event or process that is considered part of normal 
operations is the dislodgement of radioactive crud from CSNF assembly surfaces. Dislodgement 
of crud could result from unplanned events such as collisions involving handling equipment, or 
from normal handling movements, vibrations, thermal expansion, or other normal conditions 
expected during normal operations. The potential events that are considered part of normal 
operations will not lead to further degradation or failure of SNF cladding. Exposure of workers 
to radiation will be managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation doses. 
Requirements that may be needed to control normal operations doses are beyond the scope of the 
present analysis. 
Table 54. Potential Events Considered Part of Normal Operations 
Identifier Description 
Cross-Reference 
(Section Number) 
CHF; Canister Transfer Cell (Canister Transfer) 
1 Damage or rupture of cask sampling and purging system, leading to a 
release of cask internal gases and radioactive material 
6.3.3.2.5.3 
2 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.3.2.5.4 
CHF; WP Closure 
3 Glovebox leak leads to a radiological release 6.3.3.4.5.2 
DTF; Cask/MSC Turntable Room, Cask Preparation Room 
4 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.2.2.1 
6.3.4.2.4.5 
5 Damage or rupture of cask sampling and purging system, leading to a 
release of cask or MSC internal gases and radioactive material 
6.3.4.2.5.2 
6 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.4.2.5.3 
DTF; Cask and MSC Docking Room 
7 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.3.2.1 
6.3.4.3.4.4 
8 Thermal expansion of gases inside a cask or MSC leads to radiological 
release 
6.3.4.3.5.4 
DTF; Waste Transfer Cell, WP Docking Cell, WP Loading/Docking Ring 
Removal Cell 
9 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.7.2.1
Categorization of Event Sequences for License Application 
Table 54 (Continued). Potential Events Considered Part of Normal Operations 
000-00C-MGR0-00800-000-00B 352 April 2005 
Identifier Description 
Cross-Reference 
(Section Number) 
10 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.4.7.5.5 
DTF; Loaded MSC Removal: Cask and MSC Docking Room, Cask/MSC 
Turntable Room, Cask Restoration Room, Cask and MSC to Trolley 
Transfer Room, Cask and MSC SRTC Receipt Area, Cask and MSC 
Entrance Vestibule 
11 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.9.2.1 
12 Damage or rupture of cask inerting system leading to a release of MSC 
internal gases 
6.3.4.9.5.2 
13 Expansion of gases in the loaded, unsealed MSC, leading to radiological 
release 
6.3.4.9.5.3 
DTF; WP Handling and Staging Cell, WP Positioning Cells, WP Closure 
Cells, and the WP/Trolley Decontamination Room 
14 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.10.2.1 
15 Flooding due to rupture of water line or clogging of drain associated with the 
high pressure water system used for decontamination activities in the 
WP/trolley decontamination room 
6.3.4.10.2.2 
16 Glovebox leak leads radiological release of airborne contamination 6.3.4.10.5.2 
17 Thermal expansion of gases within WP (prior to seal of inner lid) leads to 
radiological release. 
6.3.4.10.5.3 
DTF; WP Remediation: DPC Cutting/WP Dry Remediation Cell 
18 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.12.2.1 
6.3.4.12.4.4 
19 Damage or rupture of the WP sampling and purging system, leading to a 
release of WP internal gases and radioactive material 
6.3.4.12.5.2 
20 Thermal expansion of gases or other loss of confinement in an unsealed 
cask, leading to radiological release 
6.3.4.12.5.4 
DTF; Dry Cask Remediation: Cask Docking/Dry Remediation Room, 
Tool Spare Transfer Room, DPC Cutting/WP Dry Remediation Cell 
21 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.13.2.1 
6.3.4.13.4.3 
22 Damage or rupture of the cask and MSC sampling and purging system, 
leading to a release of canister internal gases and radioactive material 
6.3.4.13.5.2 
23 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.4.13.5.4 
DTF; Wet Cask Remediation: Cask Wet Remediation/Laydown Area, 
Cask Wet Remediation Entrance Vestibule 
24 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.14.2.5 
6.3.4.14.4.10 
25 Damage or rupture of the cask sampling and purging system, leading to a 
release of internal gases and radioactive material 
6.3.4.14.5.1 
26 Uncontrolled pool water draindown/fill or leak of pool cooling or water 
treatment system resulting in flooding and radioactive contamination of 
adjoining areas 
6.3.4.14.5.2 
27 Insufficient cooling of a cask or loss of the cask cooling system prior to 
lowering of a cask into the pool, leading to a release of radiologically 
contaminated steam or gases 
6.3.4.14.5.6
Categorization of Event Sequences for License Application 
Table 54 (Continued). Potential Events Considered Part of Normal Operations 
000-00C-MGR0-00800-000-00B 353 April 2005 
Identifier Description 
Cross-Reference 
(Section Number) 
28 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.4.14.5.7 
DTF; DPC Cutting: DPC Preparation/Cask Dry Remediation Room, DPC 
Docking Room, DPC Cutting/WP Dry Remediation Cell 
29 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.4.15.2.1 
6.3.4.15.4.5 
30 Damage or rupture of the DPC sampling and purging system, leading to a 
release of canister internal gases and radioactive material 
6.3.4.15.5.2 
31 Thermal expansion of gases or other loss of confinement in an unsealed 
cask, leading to radiological release 
6.3.4.15.5.4 
FHF; FHF Preparation Room 
32 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.5.2.2.1 
6.3.5.2.4.5 
33 Damage or rupture of cask sampling and purging system, leading to a 
release of cask internal gases and radioactive material 
6.3.5.2.5.2 
34 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.5.2.5.3 
FHF; FHF Main Transfer Room, Fuel Transfer Bay, Fuel Transfer Room 
(SNF Assembly Transfer) 
35 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.5.4.2.1 
6.3.5.4.4.7 
36 Thermal expansion of gases or other loss of confinement in an unsealed cask 
or MSC, leading to radiological release 
6.3.5.4.5.4 
FHF Main Transfer Room (Canister Transfer) 
37 Thermal expansion of gases or other loss of confinement in an unsealed 
cask, leading to radiological release 
6.3.5.5.5.3 
FHF Main Transfer Room, WP Positioning Cell, WP Closure Cell (WP 
Closure) 
38 Non-intact SNF oxidation or oxidation of damaged SNF and degradation due 
to exposure to a non-inerted environment at normal operating temperatures 
6.3.5.6.2.1 
39 Glovebox leak leads to a radiological release 6.3.5.6.5.2 
FHF Main Transfer Room, Preparation Room, Entrance Vestibule 
(Loaded MSC Removal) 
40 Damage or rupture of cask inerting system leading to a release of cask 
internal gases 
6.3.5.8.5.2 
41 Expansion of gases in the MSC, leading to radiological release 6.3.5.8.5.3 
Subsurface 
42 Release of Activated Air and Dust to the Environment 6.3.6.5.3 
6.3.10.4.2 
Surface Facilities Site-Generated Radiological Waste Disposal 
43 Drop of a heavy load onto a tank, piping, or a container containing liquid or 
solid radioactive waste 
6.3.12.1.1 
44 Drop of a container or drum containing solid LLW 6.3.12.1.2 
45 Drop of a container or drum containing liquid LLW 6.3.12.2.1 
46 Release of radioactive gas from the gas filtration systems or cavity gas 
sampling systems, WP evacuating and inerting systems, cask evacuating 
and inerting systems, or the system involved with the cooling of casks prior to 
immersion in the DTF remediation area pool 
6.3.12.2.2
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 354 April 2005 
8 REFERENCES 
References are ordered alphabetically by author. For documents by the same author, references 
are numbered by increasing year and then alphabetically by title. Document Input Reference 
System (DIRS) numbers are provided at the beginning of each reference to distinguish citations 
that have the same author and date. 
158535 10 CFR 63. 2002 Energy: Disposal of High-Level Radioactive Wastes in a Geologic 
Repository at Yucca Mountain, Nevada. TIC: 253816. 
171308 10 CFR 71. 2004 Energy: Packaging and Transportation of Radioactive Material. TIC: 
256942. 
173162 10 CFR 100. 2004 Energy: Reactor Site Criteria. TIC: 256942. 
172857 Anderson, M.J. 2005. "Scope for Analysis to Define Waste Package Transporter and 
Emplacement Gantry Maximum Speeds." Interoffice memorandum from M.J. Anderson (BSC) 
to M.J. Prytherch, February 23, 2005, 0222054799, with attachment. ACC: 
MOL.20050223.0148 
157560 BSC (Bechtel SAIC Company) 2001. Waste Package Misload Probability. CAL-WHSMD-
000001 REV 00. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011212.0186. 
162182 BSC (Bechtel SAIC Company) 2002. 2002 Operational Waste Stream Assumptions. 
TDR-CRW-SE-000024 REV 00. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
MOV.20021018.0002. 
165731 BSC (Bechtel SAIC Company) 2003. Design and Engineering, Emplacement Pallet 
Configuration. 000-M00-TEP0-00102-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: ENG.20031006.0004 
166015 BSC (Bechtel SAIC Company) 2003. Geologic Repository Operations Area Waste 
Stream Handling Process and Facilities Study. 000-30R-MGR0-00300-000 REV 00. Las Vegas, 
Nevada: Bechtel SAIC Company. ACC: MOL.20031212.0021. 
162761 BSC (Bechtel SAIC Company) 2003. Industrial/Military Activity-Initiated Accident 
Screening Analysis. ANL-WHS-SE-000004 REV 01. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: DOC.20030416.0004. 
165572 BSC (Bechtel SAIC Company) 2003. Underground Layout Configuration. 800-P0CMGR0-
00100-000-00E. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20031002.0007.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 355 April 2005 
170024 BSC (Bechtel SAIC Company) 2004. Analysis of Mechanisms for Early Waste 
Package/Drip Shield Failure. CAL-EBS-MD-000030 REV 00C. Las Vegas, Nevada: Bechtel 
SAIC Company. ACC: DOC.20040913.0006. 
168508 BSC (Bechtel SAIC Company) 2004. Bounding Characteristics of Credible Rockfalls of 
Preclosure Period. 800-00C-MGR0-00200-000-00A. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: ENG.20040315.0009. 
172428 BSC (Bechtel SAIC Company) 2004. BSC Engineering Study, Waste Package Closure 
Welding Process Characteristics. 000-30R-HW00-00300-000-000. Las Vegas, Nevada: Bechtel 
SAIC Company. ACC: ENG.20041119.0001. 
169766 BSC (Bechtel SAIC Company) 2004. Commercial SNF Waste Package Design Report. 
000-00C-DSU0-02800-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040709.0001. 
172035 BSC (Bechtel SAIC Company) 2004. DOE and Commercial Waste Package System 
Description Document. 000-3YD-DS00-00100-000-005. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: ENG.20041006.0011. 
168381 BSC (Bechtel SAIC Company) 2004. Emplacement and Retrieval General Arrangement 
Drip Shield Gantry. 800-MQ0-SSP0-00101-000-00B. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: ENG.20040303.0046. 
171251 BSC (Bechtel SAIC Company) 2004. Emplacement and Retrieval System Description 
Document. 800-3YD-HE00-00100-000-003. Las Vegas, Nevada: Bechtel SAIC Company. 
171471 BSC (Bechtel SAIC Company) 2004. Extreme Wind/Tornado/Tornado Missile Hazard 
Analysis. 000-00C-WHS0-00100-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20041105.0001. 
171488 BSC (Bechtel SAIC Company) 2004. Fire-Induced Event Sequence Analysis. 000-00CMGR0-
01300-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20041208.0001. 
170292 BSC (Bechtel SAIC Company) 2004. Ground Control for Emplacement Drifts for LA. 
800-K0C-SSE0-00100-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040712.0019. 
170022 BSC (Bechtel SAIC Company) 2004. Initial Radionuclide Inventories. ANL-WIS-MD- 
000020 REV 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: DOC.20040921.0003. 
172098 BSC (Bechtel SAIC Company) 2004. Low-Level Radioactive Waste Management System 
Description Document. 100-3YD-MR00-00100-000-007. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: ENG.20041209.0001.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 356 April 2005 
167266 BSC (Bechtel SAIC Company) 2004. Monitored Geologic Repository External Events 
Hazards Screening Analysis. 000-00C-MGR0-00500-000-00A. Las Vegas, Nevada: Bechtel 
SAIC Company. ACC: ENG.20040712.0004. 
169885 BSC (Bechtel SAIC Company) 2004. Postclosure Modeling and Analyses Design 
Parameters. TDR-MGR-MD-000037 REV 00. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: DOC.20041109.0002. 
170564 BSC (Bechtel SAIC Company) 2004. Preclosure Seismic Design Methodology for a 
Geologic Repository at Yucca Mountain. TDR-WHS-MD-000004 REV 01. Las Vegas, Nevada: 
Bechtel SAIC Company. ACC: DOC.20040827.0011. 
171599 BSC (Bechtel SAIC Company) 2004. Project Design Criteria Document. 000-3DRMGR0-
00100-000-003. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20041124.0001. 
167182 BSC (Bechtel SAIC Company) 2004. Rock Fall on Waste Packages. 000-00C-MGR0- 
01400-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. ACC: ENG.20040225.0012. 
168963 BSC (Bechtel SAIC Company) 2004. Rockfall Impact on Waste Package Transporter 
Shield. 800-K0C-SSD0-00100-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040601.0050. 
171470 BSC (Bechtel SAIC Company) 2004. Seismic Analysis for Preclosure Safety. 000-00CMGR0-
00700-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20041216.0031. 
171161 BSC (Bechtel SAIC Company) 2004. SNF Aging System Description Document. 170- 
3YD-HA00-00100-000-003. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040916.0001. 
168132 BSC (Bechtel SAIC Company) 2004. Surface Facility Criticality Safety Calculations. 
100-00C-WHS0-00100-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040309.0001. 
172176 BSC (Bechtel SAIC Company) 2004. Thermal Calculation for Off-Normal Scenarios. 
800-K0C-WIS0-00500-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20050105.0003. 
171457 BSC (Bechtel SAIC Company) 2004. Thermal Evaluation of the Waste Package in the 
Transporter. 000-00C-DSU0-03700-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: ENG.20040818.004.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 357 April 2005 
168792 BSC (Bechtel SAIC Company) 2004. U.S. Department of Energy Spent Nuclear Fuel 
Canister Survivability. 000-PSA-WHS0-00100-000-000 REV 00. Las Vegas, Nevada: Bechtel 
SAIC Company. ACC: ENG.20040719.0001. 
169062 BSC (Bechtel SAIC Company) 2004. Waste Package Envelope Dimensions for 
Facilities & Handling. 000-B20-MGR0-00101-000-00A. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: ENG.20040423.0004. 
169554 BSC (Bechtel SAIC Company) 2004. Waste Package Transporter Preclosure Safety 
Analysis. 800-MQC-HET0-00200-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040623.0002. 
167860 BSC (Bechtel SAIC Company) 2004. Waste Transfer Pool System Calculation. 130- 
M0C-MRP0-00100-000-00C. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040225.0015. 
168205 BSC (Bechtel SAIC Company) 2004. Wildfire Exposure Calculation. 000-00C-MGR0- 
00400-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. ACC: ENG.20040211.0001. 
171786 BSC (Bechtel SAIC Company) 2005. Frequency Analysis of Aircraft Hazards for 
License Application. 000-00C-WHS0-00200-000-00B. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: ENG.20050214.0009. 
171428 BSC (Bechtel SAIC Company) 2005. Internal Hazards Analysis for License Application. 
000-00C-MGR0-00600-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20050217.0009. 
166275 Canori, G.F. and Leitner, M.M. 2003. Project Requirements Document. TER-MGR-MD- 
000001 REV 02. Las Vegas, Nevada: Bechtel SAIC Company. ACC: DOC.20031222.0006. 
169064 Cogema. 2004. Navy Event Drop Heights. COGEMA-C0115-EN-CLC-0001, Rev. 3. 
Las Vegas, Nevada: Cogema. ACC: ENG.20040422.0040. 
167153 Cogema. 2003. Remediation System SNF Staging Racks Mechanical Equipment 
Envelope. YMP-C0115-0738, Rev. A. Las Vegas, Nevada: Cogema. ACC: 
ENG.20040123.0122. 
171793 Cogema. 2004. SNF Aging System Safety Study. COGEMA-C0115-RP-04-005, Rev. 1. 
Las Vegas, Nevada: Cogema. ACC: ENG.20040917.0002. 
156981 Collins, T.E. and Hubbard, G. 2001. Technical Study of Spent Fuel Pool Accident Risk at 
Decommissioning Nuclear Power Plants. NUREG-1738. Washington, D.C.: U.S. Nuclear 
Regulatory Commission. TIC: 250624.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B 358 April 2005 
170557 Curry, P.M. 2004. Project Functional and Operational Requirements. TDR-MGR-ME- 
000003 REV 02. Las Vegas, Nevada: Bechtel SAIC Company. ACC: DOC.20040714.0003. 
171945 DOE (U.S. Department of Energy) 2004. Civilian Radioactive Waste Management 
System Requirements Document. DOE/RW-0406, Rev. 06. Washington, D.C.: U.S. Department 
of Energy, Office of Civilian Radioactive Waste Management. ACC: DOC.20040929.0001. 
146564 Eide, S.A. and Calley, M.B. 1993. "Generic Component Failure Data Base." PSA '93, 
Proceedings of the International Topical Meeting on Probabilistic Safety Assessment, 
Clearwater Beach, Florida, January 26-29, 1993. 2, 1175-1182. La Grange Park, Illinois: 
American Nuclear Society. TIC: 247455. 
168640 EPRI (Electric Power Research Institute) 2002. Losses of Off-Site Power at U.S. Nuclear 
Power Plants Through 2001. EPRI TR-1002987. Palo Alto, California: Electric Power Research 
Institute. TIC: 255136. 
156397 Framatome ANP (Advanced Nuclear Power) 2001. Summary, Commercial Nuclear Fuel 
Assembly Damage/Misload Study  1985-1999. [Lynchburg, Virginia]: Framatome Advanced 
Nuclear Power. ACC: MOL.20011018.0158. 
122506 Mood, A.M.; Graybill, F.A.; and Boes, D.C. 1974. Introduction to the Theory of 
Statistics. 3rd Edition. New York, New York: McGraw-Hill. TIC: 242626. 
109988 Naples, E.M. 1999. Thermal, Shielding, and Structural Information on the Naval Spent 
Nuclear Fuel (SNF) Canister. Letter from E.M. Naples (Department of the Navy) to D.C. Haught 
(DOE/YMSCO), August 6, 1999, with enclosures. ACC: MOL.19991001.0133. 
172451 Raughley, W.S. and Lanik, G.F. 2003. Operating Experience Assessment - Effects of 
Grid Events on Nuclear Power Plant Performance. NUREG-1784. Washington, D.C.: U.S. 
Nuclear Regulatory Commission. ACC: MOL.20041206.0002. 
103311 Regulatory Guide 1.29, Rev. 3. 1978. Seismic Design Classification. Washington, D.C.: 
U.S. Nuclear Regulatory Commission. Readily available. 
139383 Swain, A.D. and Guttmann, H.E. 1983. Handbook of Human Reliability Analysis with 
Emphasis on Nuclear Power Plant Applications Final Report. NUREG/CR-1278. Washington, 
D.C.: U.S. Nuclear Regulatory Commission. TIC: 246563. 
128733 Weast, R.C., ed. 1978. CRC Handbook of Chemistry and Physics. 59th Edition. West 
Palm Beach, Florida: CRC Press. TIC: 246814. 
156713 YMP (Yucca Mountain Site Characterization Project) 2001. Yucca Mountain Site 
Characterization Project Requirements Document (YMP-RD). YMP/CM-0025, Rev. 4, DCN 02. 
Las Vegas, Nevada: Yucca Mountain Site Characterization Office. ACC: MOL.20010322.0491; 
MOL.20011107.0002.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B I-1 April 2005 
ATTACHMENT I 
POTENTIAL CRITICALITY FOR NAVAL CANISTERS 
I.1. PURPOSE 
The purpose of this attachment is to evaluate the probability of the following event sequence, 
which may occur in the DTF, the CHF, and the FHF: 
1. A crane failure causes a naval canister to be dropped while lifted, or a piece of equipment is 
dropped onto the canister. 
2. The canister breaches. 
3. The crane lubrication tank fails and oil enters the breached canister, leading to a potential 
criticality event. 
The oil that is for lubrication can act as a moderator when it enters the canister from the crane. 
The use of a lubricant with low moderator properties would make the event sequence less likely. 
I.2 QUALITATIVE EVALUATION 
Conservatively, it is considered that the naval canister will breach when dropped from the crane 
or hit by some piece of equipment. Nevertheless, it is expected that the breached area will be 
small, because of the ductile nature of the canister, which is made of stainless steel (Naples 1999 
[DIRS 109988], Enclosure 3, p. 4). 
When accidentally released, the naval canister may drop back in the transportation cask or WP, 
or it could drop onto the concrete floor of the facility. When hit by some piece of equipment, a 
comparable chain of events could unfold: the canister could breach on impact, tip over, and fall 
onto the concrete floor. For oil from the crane to enter the canister, two scenarios for the 
position of the canister breach can be considered: 1) the breached part of the canister is in contact 
with, or very close to the ground, or 2) the canister takes other possible positions (i.e., there is a 
significant distance between the breached part of the canister and the ground). 
In the first scenario, the oil released by the failed crane lubrication tank may reach the canister by 
flowing on the ground. In this scenario, the quantity of oil that could enter the canister is small 
because, to penetrate inside the canister, the oil needs to gain potential energy since the interior 
of the canister is higher in elevation than the ground. This can be done by transferring kinetic 
energy from the oil flow, but this would require a geometric configuration in which the oil would 
somehow be funneled to the canister breach without another way to escape, which is unrealistic 
for oil flowing freely on the ground. Also, a criticality event could occur only if a significant 
amount of oil was to enter the breached canister, and only if the oil was distributed in a particular 
manner inside the canister, which is implausible under these conditions. Another means for the 
oil to enter the canister is through capillary forces, but only an insignificant amount can enter the 
canister that way. Finally, with a maximum diameter of around 66 inches (Naples 1999 [DIRS 
109988], Enclosure 3, p. 2), a naval canister that breaches on impacting the concrete floor and 
that rolls just a few degrees will be out of reach of oil flowing on the ground.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B I-2 April 2005 
In the second scenario, a significant amount of oil released by the failed lubrication tank will 
enter the canister only if the canister breach is located directly under or in sufficient proximity to 
the pathway of the oil flowing down from the crane lubrication tank to the ground. Given the 
small dimensions of the canister breach, this scenario can be considered unlikely. Oil is likely to 
reach the canister breach only if it is splashed around a large area; but, in that case, the amount 
that will enter the canister will be small because only a small fraction will actually contact the 
breached area of the canister. 
Based on this qualitative evaluation, the event sequence described in Section I.1 appears to be 
unlikely, because it requires that the flow of oil be somehow funneled to the breach, and the 
equipment configuration and surface facility layout do not promote such funneling. 
Nevertheless, in the following section, it is considered that if there is an oil flow, it will enter the 
breached canister in a sufficient amount to cause criticality. When combined with the breached 
naval canister that results from a drop or impact to the canister, the criticality event sequence 
described in Section I.1 can be rewritten as follows: 
1. Occurrence of a crane failure or equipment drop, conservatively assumed to cause a naval 
canister to be breached. 
2. The crane lubrication tank fails and oil enters the breached canister, leading to a potential 
criticality event. 
The probability of this event sequence is evaluated in Section I.3. 
I.3 QUANTITATIVE EVALUATION 
Only a catastrophic failure of the crane lubrication tank is considered in this assessment. This is 
because a minor failure, such as a small leakage occurring over time, would be noticed (through 
a low-oil-level alarm prompted by a level sensor on the lubrication tank for example, or simply 
by noticing oil drops on the floor or on equipment) and repaired by corrective maintenance. 
Also, a slow leak would cause the oil to be dispersed in space and in time, such that it would not 
be available to enter a canister. The following plausible causes of catastrophic failure of the 
lubrication tank have been identified: 
 Thermal stress. When exposed to a significant heat flux, which would result from a fire, the 
seals or pressure relief valve of the tank could rupture. 
 Mechanical stress. A seismic event or a random mechanical failure, such as the rupture of a 
manual valve normally used to drain the tank during maintenance could cause the 
catastrophic failure of the tank. 
Because the drop of a piece of equipment is also the result of the failure of the crane to maintain 
its load-holding function, the events: canister drop or handling equipment dropped onto the 
canister do not need to be distinguished further and can be lumped together under the general 
description failure of load-holding function of the crane. The following plausible causes of 
canister breach due to the failure of the load-holding function of the crane have been identified:
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B I-3 April 2005 
 Thermal stress caused by a fire. Fire events, however, do not require further consideration 
because a fire will cause the oil from the lubrication tank to be burned. Therefore, the oil 
cannot be available as a moderator. 
 Mechanical stress. A seismic event or a random mechanical failure (hoist failure for 
example) could cause the crane to lose its load-holding function. 
From the previous lists of causes of failures, fires (through thermal stress) and seismic events 
(through mechanical stress) are the only phenomena that would lead, through a common-cause 
mechanism, to the concurrent catastrophic failure of the lubrication tank and the failure of the 
load-holding function of the crane. Fires, however, would consume the oil of the lubrication 
tank and make it unavailable as a moderator, and cranes are designed such that no Category 1 or 
Category 2 event sequence that exceeds the dose limit in 10 CFR Part 63 [DIRS 158535] or leads 
to a criticality condition will unfold as a consequence of a seismic event (see Section 6.2.6). 
A random failure of the lubrication tank followed by a dependent failure of the load-holding 
function of the crane can also be eliminated from further consideration. In this scenario, an oil 
leakage could cause the crane hoist mechanism to undergo unacceptable stresses due to lack of 
lubrication, resulting in a load drop. For unacceptable stresses to develop in the hoist 
mechanism, a prolonged lack of lubrication would be needed. This, however, is not plausible 
because it would require the oil leakage to go undetected for a long time, which is not compatible 
with the highly controlled conditions under which waste transfer operations will be performed. 
Consequently, it is concluded that a concurrent catastrophic failure of the lubrication tank and 
the failure of the load-holding function of the crane could only result from concurrent 
independent failure mechanisms. 
A simplified probability calculation is now carried out to show that the event sequence involving 
the independent (random) failures of both the crane lubrication tank and the load holding 
function of the crane is not a Category 1 or Category 2 event sequence. This is done based on 
the following inputs: 
 The probability of failure of the load-holding function of the crane is calculated based on a 
crane failure rate of 10-5 drops per transfer (Assumption 5.1.1.10). 
 The frequency of failure of the crane lubrication tank is estimated based on a likely cause of 
failure, namely the internal rupture of a manual valve (which would normally be used to 
drain the tank during maintenance). For this latter failure mode, a generic failure rate of 
5.0  10-8/h is found (Eide and Calley 1993 [DIRS 146564], Table 1). This failure rate 
pertains to manual valves used in the nuclear industry, but is not incompatible with failure 
rates of manual valves used in other industries. A safety factor of 10 is applied to that 
number to account for the uncertainties related to the failure modes of the crane lubrication 
tank. This yields a failure rate of 5.0  10-7/h. 
 The naval canister is transferred twice: from the transportation cask to the WP, and, once 
inside the WP, to the welding cell.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B I-4 April 2005 
 Approximately 300 naval canisters will be accepted by the repository (Assumption 5.2.1.9). 
A factor of conservatism C equal to 1.1 is applied to that number (Section 6.1.4). 
 After the failure of the load-holding function of the crane, steps will be taken to recover the 
naval canister. Until such steps are taken, however, the lubrication tank of the crane might 
fail which could result in oil entering inside the canister (if it is breached). An exposure time 
of 24 hours is considered reasonable in this calculation, but it should be noted that the 
categorization of the event sequence is not sensitive to the numerical value used, because the 
resulting probability of criticality is much below the credibility threshold for a Category 2 
event sequence, as shown in the calculation that follows. 
The probability of a criticality event by failure of the load-holding function of the crane (i.e., 
drop of canister or drop of piece of equipment onto the canister), followed by a failure of the 
lubrication tank resulting in oil entering the canister is therefore, over the preclosure period: 
300 1.1  10-5  2  5  10-7  24 = 7.9  10-8 
This is below the Category 2 threshold of 10-4 over the preclosure period. Therefore, this event 
sequence can be eliminated from further consideration. 
I.4 CONCLUSION 
The probability of a criticality event sequence, consisting of a naval canister being breached 
because it is dropped during its transfer or, alternatively, because it is impacted by a dropped 
piece of equipment during its transfer, and into which oil leaking from a failed lubrication tank 
of the handling crane would enter, has been evaluated. 
First, a qualitative analysis showed that this event is unlikely: for a significant amount of oil to 
enter the canister, the leaking oil would have to be somehow funneled to the breach. This is not 
plausible because the breach will be of a small size, given the ductile nature of stainless steel, 
which forms the outer wall of the canister. 
Second, a quantitative analysis demonstrated that the potential for criticality from this event 
sequence is beyond Category 2. The analysis conservatively assumed that (1) the naval canister 
would breach whatever the drop height or the piece of equipment dropped, and (2) the leaking oil 
would enter the breached canister in a sufficient amount to induce criticality. 
The scenarios considered in this evaluation use lubrication oil that can act as a moderator when it 
enters the canister. The use of a lubricant with low moderator properties would make these 
scenarios even less likely.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B II-1 April 2005 
ATTACHMENT II. 
ALLOWABLE EXPOSURE TIME OF WP TRANSITING FROM TRANSPORTER 
BEDPLATE TO EMPLACEMENT DRIFT ENTRANCE 
In the following, the allowable average exposure time of a WP transiting from the rolled-out 
bedplate to the entrance of the emplacement drift is calculated. This exposure time is determined 
as the span during which the WP could be impacted by a rockfall occurring in the emplacement 
drift turnout, such that this rockfall would not be more severe that the bounding credible rockfall 
that could occur in the emplacement drifts over the preclosure period. This attachment is aimed 
at supporting Section 6.3.6.1.20. 
The calculation is based on the following equation (BSC 2004 [DIRS 168508], Equation 4), 
which, in the context of this attachment, is rewritten as follows: 
4 10 ) ( - =   K P N P ck se (Eq. II-1) 
where: 
Pse = probability of having at least one 10-4 per year seismic event while a WP is 
being transported from the transporter bedplate to the emplacement drift 
entrance 
N = number of rockfalls impacting the WP during the 10-4 per year seismic event 
Pck (K) = complementary cumulative distribution function of the rockfall kinetic energy 
K, that is, the probability that a given rockfall has a kinetic energy greater than 
K (in joules) 
As was done for the rockfalls in the emplacement drifts (Section 6.3.6.1.20), or the rockfalls 
impacting the transporters shielded compartment (Section 6.3.6.1.9), only the 10-4 per year 
seismic event is considered as an initiating event for rockfall. This is because this seismic event 
is the most severe considered during the preclosure period. Therefore, this seismic event is the 
one that will cause the most severe potential rockfalls on the WP (in terms of number of rocks 
that could impact the WP, but also in terms of their kinetic energy). To evaluate the probability 
Pse, the Poisson distribution is used because it is adequate to evaluate the probability of 
occurrence of rare events, such as earthquakes. Pse is calculated as a function of three 
parameters: fse, the frequency of the seismic event considered (fse = 10-4 y-1, or equivalently 
10-4/8760 = 1.14  10-8 h-1), Nwp, the number of WPs to be transferred (Nwp = 11,184 based on 
Table 1), and t, the average exposure time of a given WP. Determining the maximum allowable 
value of t is the purpose of this attachment. That is why Pse is now written as Pse(t) and, based 
on the formula for the Poisson distribution given by Mood et al. (1974 [DIRS 122506], pp. 93- 
95), Pse(t) can be expressed as: 
) exp( 1 ) ( t f N t P se wp se   - - = (Eq. II-2) 
Because of the low value of fse and expected small exposure time t, Pse(t) is simplified, by 
approximation to the first order, exp(x) . 1 + (x / 1!), as:
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B II-2 April 2005 
t f N t P se wp se   = ) ( (Eq. II-3) 
The number N of rockfalls impacting the WP during the 10-4 per year seismic event is evaluated 
based on the rockfall frequency (number of rockfalls per square meter) and the projected area of 
the WP. An upper value of the rockfall frequency is given by BSC (2004[DIRS 168508], 
Section 6.3.2) as 1.251 rockfalls per square meter. The maximum projected area of the WP is 
that of the Naval Long WP, which has envelope dimensions of 75.8 inches (diameter of the outer 
barrier) by 236.3 inches (total length), as indicated in Section 4.1.2. This yields an overhead 
cross-sectional area of 11.6 square meters. Therefore, N is equal to 1.251  11.6 = 14.5, which is 
rounded up to 15 rockfalls in the following. 
In the context of this attachment, Pck(K) corresponds to the probability that a rockfall occurring 
in the emplacement drift turnouts has a kinetic energy greater than K. BSC (2004 [DIRS 
168508]) does not provide the probability distribution for the kinetic energy of those nonemplacement 
drift rockfalls, but only their mass distribution. That is why Pck(K) cannot be used 
directly. Instead, the probability Pcm(M) of having an emplacement drift turnout rockfall 
exceeding a mass M is substituted to Pck(K) in Equation II-1. Information for that distribution 
exists and is given by BSC (2004 [DIRS 168508], Section 6.3.3 as well as Attachments I and 
III). 
The approach used to make the transfer from Pck(K) to Pcm(M) is given in the following. 
Based on Section 6.3.6.1.20, the WP is able to withstand the impact of a 1.2  105-joule rockfall 
without breaching. The velocity at impact of a rockfall falling from the emplacement drift 
turnouts will be governed by its free-drop height. A free-drop height of 7 m, the height of the 
turnouts (Section 4.1.6), is used. This value is conservative because BSC (2004 [DIRS 168963], 
Figure 6-2) gives the distance between the crown of the access mains and the bottom of the 
transporter steel shield that carries the WP as 2.52 + 2.93 = 5.45 m. Given that the diameter of 
the access mains is 7.62 m (BSC 2004 [DIRS 168963], Section 4.2.2.1), which is larger than the 
7 m of the nonemplacement turnouts, the 5.45 m value is already conservative. In addition, the 
5.45 m distance was calculated without taking credit for the height of the WP, which will 
decrease the available free-drop height of the potential rockfall. The velocity reached after a free 
drop of 7 m is equal to 7 . 11 7 8 . 9 2 =   m/s (Weast 1978 [DIRS 128733], pp. F-104 and F- 
335), where 9.8 is the standard acceleration of gravity (in m/s2). 
The rockfall mass corresponding to a kinetic energy of 1.2  105 joules and a rock velocity of 
11.7 m/s is, by definition of kinetic energy: 3 
2 
5 
10 8 . 1 
7 . 11 
10 2 . 1 2  = 
  
kg, or 1.8 metric tons. This 
value is assigned to M. Therefore, it can be concluded that the emplacement drift turnout 
rockfalls that have a mass of 1.8 metric tons or less will not jeopardize the structural integrity of 
the WP. The probability Pcm(M) of observing bigger rockfalls can be calculated (BSC 2004 
[DIRS 168508], Section 6.3.3 as well as Attachments I and III), and is found to be equal to 
1.2  10-2. Note that Pcm(M) is a decreasing function of M, therefore a larger value of M will 
result in a smaller probability.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B II-3 April 2005 
Combining Equation II-1 and II-3 and substituting Pck(K) with Pcm(M) yields the following new 
equation: 
) ( 
10 4 
M P N f N 
t 
cm se wp    
= 
- 
(Eq. II-4) 
Substituting the numerical values of Nwp, fse, N and Pcm(M) yields an approximate value: t = 4.5 h 
(which corresponds to 4 hours and 30 minutes). This value t corresponds to the allowable 
average time during which a WP should be transferred from the transporter bedplate to the 
entrance of the emplacement drifts. If the exposure time is less than t, the maximum credible 
size for a rockfall onto the WP will be less than 1.8 metric tons, which will not cause a WP 
breach. 
Conservatively, t is rounded down to 4 h to support Section 6.3.6.1.20.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-1 April 2005 
ATTACHMENT III. 
SUMMARY OF CATEGORIZATION RESULTS AND DERIVED REQUIREMENTS 
The results of the categorization calculations are presented in a series of tables that are contained 
in this attachment. Table III-1 lists the tables. Tables III-2 through III-37 summarize the 
potential event sequences and state the design and operational requirements that were credited in 
the categorization assignments. To avoid duplication, the requirements listed are the generalized 
requirements that address many similar events based on the assumptions in Section 5 and have 
not necessarily been customized for each specific potential event. The room numbers listed in 
Tables III-1 through III-37 are taken from the corresponding event descriptions in Internal 
Hazards Analysis for License Application (BSC 2005 [DIRS 171428]). 
Table III-1. List of Summary Tables 
Table Number 
Cross- 
Reference 
(Section) Title of Table 
III-2 6.2 Disposition of External Events 
III-3 6.3.2 Disposition of Internal Events That Occur Inside the Cask and Waste 
Package Receipt Building: Transportation Cask Receipt/Return Area (Room 
1034), Transportation Cask Buffer Area (Room 1035) 
III-4 6.3.3.1 Disposition of Internal Events That Occur Inside the Canister Handling 
Facility: Entrance Vestibule (Room 1036), Tools/Parts Storage Room (Room 
1035) 
III-5 6.3.3.2 Disposition of Internal Events That Occur Inside the Canister Handling 
Facility (Canister Transfer): Canister Transfer Cell (Room 1033) 
III-6 6.3.3.3 Disposition of Internal Events That Occur Inside the Canister Handling 
Facility (Waste Package Transfer to Waste Package Closure, Site-specific 
Cask Closure and Removal): Canister Transfer Cell (Room 1033) 
III-7 6.3.3.4 Disposition of Internal Events That Occur Inside the Canister Handling 
Facility (Waste Package Closure): Waste Package Positioning Cells (Rooms 
1011 and 1042), and Closure Cells (Rooms 2010 and 2032) 
III-8 6.3.3.5 Disposition of Internal Events That Occur Inside the Canister Handling 
Facility (Waste Package Loadout): Canister Transfer Cell. (Room 1033), 
Waste Package Tool Storage Room. (Room 1032), Exit Vestibule. (Room 
1031) 
III-9 6.3.4.1 Disposition of Internal Events That Occur Inside the Dry Transfer Facility: 
Cask and Site-specific Cask Entrance Vestibule (Room 1079), Cask and 
Site-specific Cask SRTC Receipt Area (Room 1077), Cask and Site-specific 
Cask to Trolley Transfer Room (Room 1076) 
III-10 6.3.4.2 Disposition of Internal Events That Occur Inside the Dry Transfer Facility: 
Cask/Site-specific Cask Turntable Room (Room 1073), Cask Preparation 
Room (Room 1074), Cask Docking Ring Installation Room (Room 2051) 
III-11 6.3.4.3 Disposition of Internal Events That Occur Inside the Dry Transfer Facility: 
Cask and Site-specific Cask Docking Room. (Room 1069) 
III-12 6.3.4.5 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
(Naval Spent Nuclear Fuel Receipt): Waste Package and Navy Cask 
Entrance Vestibule. (Room 1060), Waste Package/Navy Cask SRTC Receipt 
Area. (Room 1058), Waste Package/Navy to Trolley Transfer Room (Room 
1057), Waste Package/Navy Cask Preparation Room (Room 1053).
Categorization of Event Sequences for License Application 
Table III-1. Summary Tables on Compact Disk (Continued) 
000-00C-MGR0-00800-000-00B III-2 April 2005 
Table Number 
Cross- 
Reference 
(Section) Title of Table 
III-13 6.3.4.6 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
(Naval Spent Nuclear Fuel Processing): Waste Package Docking Cell 
(Rooms 1052 and 1055), Waste Package Loading (Navy Canister)/Docking 
Ring Removal Cell (Room 1051) 
III-14 6.3.4.7 Disposition of Internal Events That Occur Inside the Dry Transfer Facility: 
Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 
2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste 
Package Loading/Docking Ring Removal Cell (Room 1054) 
III-15 6.3.4.8 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
(Empty Transportation Cask/Site-specific Cask/Dual-purpose Canister 
Removal): Cask and Site-specific Cask Docking Room (Room 1069), 
Cask/Site-specific Cask Turntable Room (Room 1073), Cask Restoration 
Room (Room 1072), Cask and Site-specific Cask to Trolley Transfer Room 
(Room 1076), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), 
Cask and Site-specific Cask Entrance Vestibule (Room 1079) 
III-16 6.3.4.9 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
(Loaded Site-specific Cask Removal): Cask and Site-specific Cask Docking 
Room (Room 1069), Cask/Site-specific Cask Turntable Room (Room 1073), 
Cask Preparation Room (Room 1074), Cask and Site-specific Cask to Trolley 
Transfer Room (Room 1076), Cask and Site-specific Cask Site Rail Transfer 
Cart Receipt Area (Room 1077), Cask and Site-specific Cask Entrance 
Vestibule (Room 1079) 
III-17 6.3.4.10 Disposition of Internal Events That Occur Inside the Dry Transfer Facility: 
Waste Package Handling and Staging Cell (Room 1044), Waste Package 
Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure 
Cells (Rooms 2032, 2033, and 2035), and the Waste Package/Trolley 
Decontamination Room (Room 1094) 
III-18 6.3.4.11 Disposition of Internal Events That Occur Inside the Dry Transfer Facility: 
Waste Package Loadout Cell (Room 1088), Waste Package Transporter 
Vestibule (Room 1087), Exit Vestibule (Room 1086) 
III-19 6.3.4.12 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
(Waste Package Remediation): Dual-purpose Canister Cutting/Waste 
Package Dry Remediation Cell (Room 1097) 
III-20 6.3.4.13 Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry 
Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool 
Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste 
Package Dry Remediation Cell (Room 1097) 
III-21 6.3.4.14 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
(Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), 
Cask Wet Remediation Entrance Vestibule (Room 1120) 
III-22 6.3.4.15 Disposition of Internal Events That Occur Inside the Dry Transfer Facility 
Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 
1100), Dual-purpose Canister Docking Room (Room 1101), and Dualpurpose 
Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) 
III-23 6.3.5.1 Disposition of Internal Events That Occur Inside the Fuel Handling Facility 
(Cask and Site-specific Cask Receipt): Entrance Vestibule (Room 1001) 
III-24 6.3.5.2 Disposition of Internal Events That Occur Inside the Fuel Handling Facility: 
Preparation Room (Room 1002) 
III-25 6.3.5.4 Disposition of Internal Events That Occur Inside the Fuel Handling Facility 
(Commercial Spent Nuclear Fuel Assembly Transfer): Main Transfer Room 
(Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel 
Transfer Room (Room 2001)
Categorization of Event Sequences for License Application 
Table III-1. Summary Tables on Compact Disk (Continued) 
000-00C-MGR0-00800-000-00B III-3 April 2005 
Table Number 
Cross- 
Reference 
(Section) Title of Table 
III-26 6.3.5.5 Disposition Internal Events That Occur Inside the Fuel Handling Facility 
(Canister Transfer): Main Transfer Room (Room 1003) 
III-27 6.3.5.6 Disposition of Internal Events That Occur Inside the Fuel Handling Facility 
(Waste Package Closure): Main Transfer Room (Room 1003), Waste 
Package Positioning Cell (Room 1013), Waste Package Closure Cell (Room 
2006) 
III-28 6.3.5.7 Disposition of Internal Events That Occur Inside the Fuel Handling Facility 
(Waste Package Loadout): Main Transfer Room (Room 1003), Preparation 
Room (Room 1002), Entrance Vestibule (Room 1001) 
III-29 6.3.5.8 Disposition of Internal Events That Occur Inside the FHF (Loaded Sitespecific 
Cask Removal): Main Transfer Room (Room 1003), Preparation 
Room (Room 1002), Entrance Vestibule (Room 1001) 
III-30 6.3.5.9 Disposition Internal Events That Occur Inside the Fuel Handling Facility 
(Empty Site-specific Cask Removal): Main Transfer Room (Room 1003), 
Preparation Room (Room 1002), Entrance Vestibule (Room 1001) 
III-31 6.3.6 Disposition of Internal Events That Occur During Waste Package Subsurface 
Transport and Emplacement 
III-32 6.3.8 Disposition of Internal Events That Occur During Subsurface Construction 
III-33 6.3.9 Disposition of Internal Events That Occur During Surface Construction 
III-34 6.3.10 Disposition of Internal Events That Occur During Subsurface Drip Shield 
Installation 
III-35 6.3.12 Disposition of Internal Events That Occur During Disposal of Low-Level 
Radioactive Waste 
III-36 6.3.7 Disposition of Internal Events That Occur in the Spent Nuclear Fuel Aging 
System: Vertical Aging Systems 
III-37 6.3.7 Disposition of Internal Events That Occur in the SNF Aging System: 
Horizontal Aging Systems
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-4 April 2005 
Table III-2. Disposition of External Events 
Disposition of Event 
External Event Hazards Potential Event 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Aircraft Crash Aircraft operations near enough to the repository to pose a hazard to 
surface structures have been identified as an external hazard. 
Aircraft operations considered are from the Beatty Corridor and the 
restricted airspace of the Nevada Test Site and the Nevada Test and 
Training Range. The hazards considered are DOE aircraft, small 
military aircraft, large military aircraft, dropped objects from aircraft, 
and aircraft in public air space. 
EXT-AC Beyond Category 2 Facility and component structural design requirements and operational restrictions on 
aircraft operations ensure that event sequences initiated by aircraft hazards are beyond 
Category 2. 
Preventive Design- 
Procedural 
Safety 
Rainstorm and Flooding Rainstorm has been identified as an external hazard. EXT-RNFL Beyond Category 2 Design requirements prevent initiation of event sequences caused by precipitation 
(including rainstorm) during the preclosure period by specifying reasonable maximum 
annual, daily, and hourly precipitation rates that the repository is designed to withstand 
while operating. 
Preventive Design 
Range Fire Range fire has been identified as an external hazard. EXT-RGFIR Beyond Category 2 Separation distance between combustible vegetation and nearest structure containing 
radiological materials is at least 33 ft and complies with applicable fire protection codes and 
standards for protection of structures from wildfire exposure and hazards. Compliance with 
regulatory requirements and adherence to fire protection codes and standards ensure that 
range fires are mitigated before they pose a hazard that could involve a release of 
radioactive material. Thus, range fire is screened out as an initiating event. 
Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
Loss of Offsite-Onsite 
Power 
Loss of offsite-onsite power has been identified as an 
external hazard. 
EXT-LOSP Beyond Category 2 Design requirements ensure that surface facilities are designed so that a loss of offsite or 
onsite electrical power does not initiate an event sequence. 
Preventive Design 
Nearby Industrial and 
Military Facilities 
Nearby military and industrial activities have been identified as an 
external hazard. 
EXT-NIMF NA There are no known existing or planned military or industrial activities that might be 
expected to initiate an event sequence with potential radiological consequences to offsite 
individuals or workers during the preclosure period. 
NA NA 
Seismic Activity Seismic activity has been identified as an external hazard. EXT-SEISMIC-A 
EXT-SEISMIC-B 
Category 2 
Beyond Category 2 
Design requirements ensure that facilities are designed so that seismic events do not 
initiate a Category 1 or Category 2 event sequence that leads to a potential dose to 
workers or the public that exceed the performance objectives of 10 CFR 63.111 or that 
leads to a criticality condition. The application of the seismic design requirements 
precludes the occurrence of any seismically initiated event sequence having a mean 
annual probability of 10-3 or greater and, therefore, precludes the occurrence of a Category 
1 seismically initiated event sequence. 
A - Seismically initiated event sequences that are mitigated or prevented by the use of a 
DBGM-1 assignment to a SSC are less probable than the Category 1 occurrence criterion, 
implicitly, such event sequences are Category 2. The only seismically initiated Category 2 
event sequences of concern are 1) failure of the spent fuel transfer machines in the DTF 
and FHF leading to dropped CSNF fuel assemblies, 2) failure of the fuel handling machine 
in wet remediation leading to a dropped CSNF fuel assembly or basket loaded with fuel 
assemblies, 3) failure of HEPA filters leading to discharge of accumulated activity, and 4) 
failure of ducting and dampers leading to discharge of accumulated activity. 
B - A DBGM-2 assignment to a SSC ensures that the corresponding seismically initiated 
event sequences are Beyond Category 2. 
Further, design requirements ensure that portions of a non-ITS SSC which, upon failure, 
could adversely interact with an ITS SSC and prevent its safety function from being 
performed are classified as ITS, redesigned to eliminate the potential unacceptable 
interaction with the identified ITS SSC, or, for seismic interactions, designed to the same 
seismic DBGM as the ITS SSCs subjected to the potential unacceptable interaction. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-5 April 2005 
Table III-2. Disposition of External Events (Continued) 
Disposition of Event 
External Event Hazards Potential Event 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Tornado and Extreme 
Wind 
Tornado and extreme wind have been identified as an 
external hazard. 
EXT-WDTONADO Beyond Category 2 To render event sequences involving tornado and extreme wind Beyond Category 2, 
design requirements ensure that stationary ITS (important to safety) structures, as well as 
aging casks, are designed for tornado missiles, extreme straight wind, and tornado wind. 
Tornado missiles and tornado wind are screened out for transporters (including WP 
transporters and transporters used to carry waste to and from the aging pads); however, 
transporters must be designed to function in extreme straight wind. For transportation and 
transfer casks on the repository site, the certification process for transportation casks under 
10 CFR Part 71 and similarity of transfer cask design requirements ensure that casks 
provide adequate protection against external hazards. 
Preventive Design 
Lightning Lightning has been identified as an external hazard. EXT-LIGHTN Beyond Category 2 Design requirements ensure that surface buildings and elevated structures, and the SNF 
aging system are designed so that a lightning strike does not initiate an event sequence. 
For transportation and transfer casks on the repository site, the certification process for 
transportation casks under 10 CFR Part 71 and similarity of transfer cask design 
requirements ensure that casks provide adequate protection against external hazards. 
Preventive Design 
Volcanism-Ash Fall Volcanism-ash fall has been identified as an external hazard. Ash 
fall could occur at the North Portal facilities as the result of a 
regional volcanic eruption. 
EXT-ASHFAL Beyond Category 2 A design requirement ensures that surface facilities, including the SNF aging system, 
where SNF and HLW are handled or stored are designed to withstand the effects of ash fall 
from a regional volcanic eruption without loss of capability to perform their safety function. 
Preventive Design 
Drift Degradation Drift degradation has been identified as an external hazard. 
Drift degradation in the partial or complete collapse of main, turnout, 
or emplacement drifts can occur as a result of rockfall. 
EXT-DRFDEG Beyond Category 2 Credible rockfall scenarios do not damage the waste package in a manner sufficient to 
jeopardize the structural integrity of the waste package. Therefore, a credible rockfall 
does not initiate a Category 1 or Category 2 event sequence. See disposition of internal 
event sequences SS-TE-CC9, SS-TE-CC20, and SS-TE-CC21 (Table III-31) for 
rockfall evaluations. 
Preventive Design 
Extreme Weather 
Fluctuation-Temperature 
Extreme weather fluctuation-temperature has been identified as an 
external hazard. 
EXT-EXTRWEATH Beyond Category 2 A design requirement for SNF aging casks (including MSCs and HAMs) on the aging pads 
ensures that temperature extremes do not initiate a Category 1 or Category 2 event 
sequence. For transportation and transfer casks on the repository site, the certification 
process for transportation casks under 10 CFR Part 71 and similarity of transfer cask 
design requirements ensure that casks provide adequate protection against external 
hazards. 
Preventive Design 
Sandstorm Sandstorm has been identified as an external hazard. EXT-SANDSTRM Beyond Category 2 An operational requirement ensures that filters or natural circulation vent paths of SNF 
aging casks (including MSCs and HAMs), that could be clogged as a result of a sandstorm, 
other events, or chronic conditions, are inspected and maintained in an operable condition. 
Preventive Procedural 
Safety 
NOTES: AC = aircraft crash; ASHFAL = volcanism-ash fall; DOE = U.S. Department of Energy; DRFDEG = drift degradation; EXT = external; EXTRWEATH = extreme weather fluctuation-temperature; HLW = high-level radioactive waste; LIGHTN = lightning; LOSP = loss of offsiteonsite 
power; NA = not applicable; NIMF = nearby industrial and military facilities; RGFIR = range fire; RNFL = rainstorm and flooding; SANDSTRM = sandstorm; SNF = spent nuclear fuel; SS = subsurface; TE = transport and emplacement; WDTONADO = Tornado and 
Extreme Wind. 
The Event Sequence Designator is a unique event sequence index for each event. The prefix identifies the location, for example EXT. The next letters, identify an event, for example SANDSTRM. For events with multiple sequences, the last letter is the event identifier, 
for example A.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-6 April 2005 
Table III-3. Disposition of Internal Events That Occur Inside the Cask and Waste Package Receipt Building: Transportation Cask Receipt/Return Area (Room 1034), Transportation Cask Buffer Area (Room 1035) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Overturning or collision of a site prime mover moving an LWT or 
an OWT trailer holding a transportation cask (with impact limiters 
and personnel barrier installed) (Room 1034). 
CWPRB-TCBA-CC1 Beyond Category 2 Transportation casks with impact limiters are designed to withstand, without breaching, the 
bounding drops that could occur during cask handling at the repository. Consequently, a 
derailment, overturning, or collision would not breach a transportation cask. 
Preventive Design 
2. Derailment, overturning, or collision involving a site prime mover 
moving an offsite railcar, holding a transportation cask (with 
impact limiters and personnel barrier installed), followed by a load 
tipover or fall (Room 1034). 
CWPRB-TCBA-CC2 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
3. Collision involving a forklift and a cask on a railcar or an LWT or 
an OWT trailer (with or without impact limiters and personnel 
barrier installed) (Room 1034). 
CWPRB-TCBA-CC3 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, mobile 
elevated platforms, and forklifts operated in the facility are not operated in a manner that 
could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
4. Collision involving a mobile elevated platform and a cask on a 
railcar or an LWT or an OWT trailer (with or without impact 
limiters and personnel barrier installed) (Room 1034). 
CWPRB-TCBA-CC4 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC3. Preventive Procedural 
Safety 
5. Drop of a transportation cask and its support skid (with impact 
limiters and personnel barrier installed) from the cask receipt and 
return area overhead crane during transfer to an SRTC (Room 
1034). 
CWPRB-TCBA-CC5 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Additionally, a design 
requirement ensures that cranes for lifting transportation and transfer casks with impact 
limiters installed are not capable of lifting a cask more than 30 ft (9 m) above the floor. 
Preventive Design 
6. Drop or collision of a transportation cask and a support skid (with 
impact limiters and personnel barrier installed) from cask receipt 
and return area overhead crane onto or against a sharp object 
during transfer to an SRTC (Room 1034). 
CWPRB-TCBA-CC6 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are free of movable puncture hazards. A design requirement limits speed for 
crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
7. Drop of a transportation cask with impact limiters and personnel 
barrier removed (including the naval SNF cask or a transportation 
cask carrying a horizontal DPC not going to the SNF Aging 
System) from the cask receipt and return area overhead crane 
during transfer to an SRTC (Room 1034). 
CWPRB-TCBA-CC7A 
CWPRB-TCBA-CC7B 
CWPRB-TCBA-CC7C 
CWPRB-TCBA-CC7D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks, without impact 
limiters, and for site-specific casks. Design and operational requirements limit the 
probability of exceeding the lift height. Canister design requirements and the reliability of 
fabrication processes limit the probability that a DOE SNF canister or DOE multicanister 
overpack is defective. 
Preventive Design- 
Procedural 
Safety 
8. Drop or collision of a transportation cask with impact limiters and 
personnel barrier removed (including the naval SNF cask or a 
transportation cask carrying a horizontal DPC not going to the 
SNF Aging System) from the cask receipt and return area 
overhead crane onto or against a sharp object during transfer to 
an SRTC (Room 1034). 
CWPRB-TCBA-CC8 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC6. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-7 April 2005 
Table III-3. Disposition of Internal Events That Occur Inside the Cask and Waste Package Receipt Building: Transportation Cask Receipt/Return Area (Room 1034), Transportation Cask Buffer Area (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Drop of a transportation cask containing a horizontal DPC (with 
impact limiters and personnel barrier removed) from the cask 
receipt and return area overhead crane during transfer to a 
horizontal cask transfer trailer (for subsequent emplacement in a 
HAM) (Room 1034). 
CWPRB-TCBA-CC9A Category 2 (See GET-01 Sequence A) Design and operational requirements reduce the drop 
probability. 
Preventive Design- 
Procedural 
Safety 
10.Drop or collision of a transportation cask containing a horizontal 
DPC (with impact limiters and personnel barrier removed) from the 
cask receipt and return area overhead crane onto or against a 
sharp object during transfer to a horizontal cask transfer trailer (for 
subsequent emplacement in a HAM) (Room 1034). 
CWPRB-TCBACC10 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC6. Preventive Design- 
Procedural 
Safety 
11.Slapdown of a naval transportation cask or a transportation cask 
carrying a horizontal DPC (or other cask requiring removal of 
impact limiters prior to transfer) from the cask receipt and return 
area overhead crane back onto the railcar (forward slapdown) or 
the ground or site prime mover (backward slapdown) during the 
upending of the cask to a vertical orientation from a horizontal 
orientation during cask removal from the offsite railcar or other 
transport (Room 1034). 
CWPRB-TCBACC11A 
CWPRB-TCBACC11B 
CWPRB-TCBACC11C 
CWPRB-TCBACC11D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event CWPRB-TCBA-CC7. Preventive Design- 
Procedural 
Safety 
12.Slapdown of a naval transportation cask (or other cask requiring 
removal of impact limiters prior to transfer) from the cask receipt 
and return area overhead crane onto the SRTC (forward 
slapdown) or the ground or SRTC tractor (backward slapdown) 
during the downending of the cask from a vertical to a horizontal 
orientation after cask removal from the offsite railcar or other 
transport (Room 1034). 
CWPRB-TCBACC12A 
CWPRB-TCBACC12B 
CWPRB-TCBACC12C 
CWPRB-TCBACC12D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event CWPRB-TCBA-CC7. Preventive Design- 
Procedural 
Safety 
13.Slapdown of a transportation cask holding a horizontal DPC (with 
impact limiters removed) from the cask receipt and return area 
overhead crane onto the horizontal cask transfer trailer or the site 
prime mover (forward slapdown) or the ground (backward 
slapdown) during the downending of the cask from a vertical to a 
horizontal orientation after cask removal from the offsite railcar or 
other transport (Room 1034). 
CWPRB-TCBACC13A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event CWPRB-TCBA-CC9. Preventive Design- 
Procedural 
Safety 
14.Overturning or collision involving the site prime mover pulling a 
horizontal cask transfer trailer holding a transportation cask 
(without impact limiters) containing a horizontal DPC at the 
TCRRF or departing the TCRRF for the HAM (Room 1034). 
CWPRB-TCBACC14 Beyond Category 2 Design requirements limit size, mass, maximum speed and motive force of the MSC 
Transporter and HTC Trailer/Tractor to limit potential damage caused by collisions. Design 
requirements preclude tipover of the MSC Transporter and HTC Trailer/Tractor during 
transfer by ensuring that transfer equipment design precludes failure modes that could 
result in tipover under design-basis load-handling conditions. Design requirements 
preclude tipover during transfer by ensuring minimum tipover resistance/stability standards 
are maintained consistent with roadway design. Design requirements ensure that reliable 
means to stop and maintain stability of the MSC Transporter and HTC Trailer/Tractor is 
provided. 
Preventive Design 
15. Runaway of a site prime mover pulling a horizontal cask transfer 
trailer holding a transportation cask (with no impact limiters) 
containing a horizontal DPC (Room 1034). 
CWPRB-TCBACC15 Beyond Category 2 Design requirements ensure that reliable means to stop and maintain stability of the MSC 
Transporter and HTC Trailer/Tractor is provided. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-8 April 2005 
Table III-3. Disposition of Internal Events That Occur Inside the Cask and Waste Package Receipt Building: Transportation Cask Receipt/Return Area (Room 1034), Transportation Cask Buffer Area (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
16.Drop or collision of handling equipment onto or against a 
transportation cask (with impact limiters and personnel barrier 
installed) (Room 1034). 
CWPRB-TCBACC16 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety 
17.Drop or collision of handling equipment onto or against a 
transportation cask (without impact limiters or personnel barrier 
installed) (Room 1034). 
CWPRB-TCBACC17 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC16. Preventive Procedural 
Safety 
18.Drop or collision of heavy loads from the maintenance crane onto 
or against a transportation cask (with or without impact limiters or 
personnel barrier installed) (Room 1034). 
CWPRB-TCBACC18 Beyond Category 2 An operational requirement ensures that heavy loads, that could potentially initiate an event 
sequence if dropped onto a transportation cask, transfer cask or waste package, can not 
be lifted over or near a transportation cask, transfer cask, or waste package, except as 
needed for transfer and closure operations. 
Preventive Procedural 
Safety 
19.Derailment of the SRTC positioner moving an SRTC holding a 
transportation cask (with impact limiters and personnel barrier 
installed) resulting in an SRTC collision or derailment followed by 
a load tipover or fall (Rooms 1034 and 1035). 
CWPRB-TCBACC19 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
20.Derailment of the SRTC positioner moving an SRTC holding a 
transportation cask (with impact limiters and personnel barrier 
installed) due to a malfunction of the turntable in the TCBA, 
resulting in an SRTC collision or derailment followed by a load 
tipover or fall (Rooms 1034 and 1035). 
CWPRB-TCBACC20 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
21.Roll-off and/or derailment of an SRTC holding a transportation 
cask (with impact limiters and personnel barrier installed) from the 
SRTC positioner followed by a load tipover or fall (Rooms 1034 
and 1035). 
CWPRB-TCBACC21 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
22. Collision of an SRTC tractor and an SRTC holding a 
transportation cask (with impact limiters and personnel barrier 
installed) (Room 1034). 
CWPRB-TCBACC22 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
23.Derailment or collision involving an SRTC holding a transportation 
cask (with impact limiters and personnel barrier installed) being 
pushed or pulled by an SRTC tractor followed by a load tipover or 
fall (Room 1034). 
CWPRB-TCBACC23 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
24.An SRTC carrying a transportation cask (with impact limiters 
installed) from the CWPRB to the TCBA, the DTF, or the CHF is 
pushed by the SRTC tractor into the SRTC positioner trench 
(Room 1034). 
CWPRB-TCBACC24 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC1. Preventive Design 
25. Drop of a transfer cask containing a horizontal DPC (with impact 
limiters removed) from the cask receipt and return area overhead 
crane during transfer from a horizontal cask transfer trailer (after 
retrieval from a HAM) to an SRTC for processing in the DTF 
(Room 1034). 
CWPRB-TCBACC25A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event CWPRB-TCBA-CC9. Preventive Design- 
Procedural 
Safety 
26. Drop or collision of a transfer cask containing a horizontal DPC 
(with impact limiters removed) from the cask receipt and return 
area overhead crane onto or against a sharp object during 
transfer from a horizontal cask transfer trailer (after retrieval from 
a HAM) to an SRTC for processing in the DTF (Room 1034). 
CWPRB-TCBACC26 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC6. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-9 April 2005 
Table III-3. Disposition of Internal Events That Occur Inside the Cask and Waste Package Receipt Building: Transportation Cask Receipt/Return Area (Room 1034), Transportation Cask Buffer Area (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
27. Slapdown of a transfer cask holding a horizontal DPC (without 
impact limiters) from the cask receipt and return area overhead 
crane back onto the horizontal cask transfer trailer or the site 
prime mover (forward slapdown) or the ground (backward 
slapdown) during the upending of the cask to a vertical orientation 
from a horizontal orientation during the transfer of the cask from 
the horizontal cask transfer trailer to an SRTC (Room 1034). 
CWPRB-TCBACC27A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event CWPRB-TCBA-CC9. Preventive Design- 
Procedural 
Safety 
28. Slapdown of a transfer cask holding a horizontal DPC (without 
impact limiters) from the cask receipt and return area overhead 
crane onto an SRTC or SRTC Tractor (forward slapdown) or the 
ground (backward slapdown) during the downending of the cask 
to a vertical orientation from a horizontal orientation after removal 
from the horizontal cask transfer trailer (Room 1034). 
CWPRB-TCBACC28A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event CWPRB-TCBA-CC9. Preventive Design- 
Procedural 
Safety 
29. Overturning or collision involving the site prime mover pulling a 
horizontal cask transfer trailer holding a transfer cask (without 
impact limiters) containing a horizontal DPC in transit to, or at, the 
TCRRF (Room 1034). 
CWPRB-TCBACC29 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC14. Preventive Design 
30.Runaway of a site prime mover pulling a horizontal cask transfer 
trailer holding a transfer cask (with no impact limiters) containing a 
horizontal DPC (Room 1034). 
CWPRB-TCBACC30 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-CC15. Preventive Design 
Chemical 
Contamination-Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1034 and 1035). 
CWPRB-TCBACCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed cask, therefore this event does not occur unless an 
event sequence leads to a potential exposure of SNF to air. Oxidation of the fuel matrix is 
a possible outcome of any event that potentially exposes SNF to air. Consequence 
analyses account for the possibility of oxidation, as applicable 
NA NA 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a forklift (Room 1034). CWPRB-TCBA-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
prevention of the generation or accumulation of enough hydrogen gas to cause an 
explosion that could breach a transportation cask, site-specific cask, or waste package. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1034). 
CWPRB-TCBA-EI2 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-EI1. Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a site prime mover 
(Room 1034). 
CWPRB-TCBAEI3 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Fire/explosion (battery/electrical fire) involving a site prime mover 
moving an LWT or an OWT trailer holding a transportation cask 
(Room 1034). 
CWPRB-TCBA-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) involving a site prime mover 
moving a railroad car holding a rail transportation cask 
(Room 1034). 
CWPRB-TCBA-FT2 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) involving a site prime mover 
pulling or pushing a horizontal cask transfer trailer holding a 
transportation cask containing a horizontal DPC (at the TCRRF or 
in transit to the HAM) (Room 1034). 
CWPRB-TCBAFT3 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) involving a site prime mover 
pulling or pushing a horizontal cask transfer trailer holding a 
transfer cask containing a horizontal DPC (at the TCRRF or in 
transit from the HAM) (Room 1034). 
CWPRB-TCBAFT4 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-10 April 2005 
Table III-3. Disposition of Internal Events That Occur Inside the Cask and Waste Package Receipt Building: Transportation Cask Receipt/Return Area (Room 1034), Transportation Cask Buffer Area (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
5. Diesel fuel fire/explosion involving an SRTC tractor pushing or 
pulling an SRTC holding a transportation cask (Room 1034). 
CWPRB-TCBAFT5 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
6. Electrical fire involving the cask receipt and return area overhead 
crane, handling equipment, or other electrical equipment 
(Room 1034). 
CWPRB-TCBAFT6 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
7. Electrical fire involving the SRTC positioner holding an SRTC 
loaded with a transportation cask (Rooms 1034 and 1035). 
CWPRB-TCBAFT7 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
8. Electrical fire involving the turntable carrying the SRTC positioner 
holding an SRTC loaded with a transportation cask (Rooms 1034 
and 1035). 
CWPRB-TCBAFT8 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
9. Fire/explosion (battery/electrical fire) associated with a forklift 
(Room 1034). 
CWPRB-TCBAFT9 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
10.Fire/explosion (battery/electrical fire) associated with a mobile 
elevated platform (Room 1034). 
CWPRB-TCBAFT10 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
11.Transient combustible fire in CWPRB or the TCBA (Room 1034). CWPRB-TCBA-FT11 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-FT1. Preventive Design- 
Procedural 
Safety 
12.Cask overheating due to solar insolation while on an offsite 
transport or an SRTC (Rooms 1034 and 1035). 
CWPRB-TCBAFT12 NA  Bounded by 
normal and 
hypothetical accident 
conditions 
Transportation casks must be evaluated under normal conditions of transport and 
hypothetical accident conditions, such as a potential exposure to insolation under normal 
conditions, or fires under hypothetical accident conditions. The normal and hypothetical 
accident conditions bound insolation on site. Therefore, the incidence of solar radiation on 
transportation casks will not initiate an event sequence. 
NA NA 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1034 and 1035). 
CWPRB-TCBAR1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Radiation-induced damage to a facility SSC (Rooms 1034 and 
1035). 
CWPRB-TCBA-R2 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a transportation cask collision, drop, or 
slapdown (involving a crane) and a rearrangement of the cask 
internals (Room 1034). 
CWPRB-TCBA-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with an offsite railcar collision or derailment 
(holding a transportation cask) followed by a load tipover or fall 
and a rearrangement of the cask internals (Room 1034). 
CWPRB-TCBA-F2 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-11 April 2005 
Table III-3. Disposition of Internal Events That Occur Inside the Cask and Waste Package Receipt Building: Transportation Cask Receipt/Return Area (Room 1034), Transportation Cask Buffer Area (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Criticality associated with a collision or overturning of an LWT or 
an OWT trailer (holding a transportation cask) and a 
rearrangement of the cask internals (Room 1034). 
CWPRB-TCBAF3 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
4. Criticality associated with an SRTC collision or derailment (holding 
a transportation cask) followed by a load tipover or fall and a 
rearrangement of the cask internals (Room 1034). 
CWPRB-TCBAF4 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
5. Criticality associated with an SRTC positioner collision or 
derailment (carrying an SRTC holding a transportation cask) 
followed by a load tipover or fall and rearrangement of the cask 
internals (Rooms 1034 and 1035). 
CWPRB-TCBAF5 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
6. Criticality associated with a transportation cask (holding a 
horizontal DPC) collision or derailment (involving a horizontal cask 
transfer trailer or railcar) followed by a load tipover or fall and a 
rearrangement of the cask internals (Room 1034). 
CWPRB-TCBAF6 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
7. Criticality associated with a transportation cask (holding a 
horizontal DPC) drop or slapdown from the cask receipt and 
return area overhead crane and a rearrangement of the cask 
internals (Room 1034). 
CWPRB-TCBAF7 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
8. Criticality associated with a transfer cask (holding a horizontal 
DPC) collision or derailment (involving a horizontal cask transfer 
trailer or an SRTC) followed by a load tipover or fall and a 
rearrangement of the cask internals (Room 1034). 
CWPRB-TCBAF8 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
9. Criticality associated with a transfer cask (holding a horizontal 
DPC) drop or slapdown from the cask receipt and return area 
overhead crane and a rearrangement of the cask internals (Room 
1034). 
CWPRB-TCBAF9 Beyond Category 2 Same disposition as Potential Event CWPRB-TCBA-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; CWPRB = Cask and Waste Package Receipt Building; DOE = U.S. Department of Energy; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; 
FT = fire-thermal; GET = generalized event tree; HVAC = heating, ventilation, and air-conditioning; LWT = legal-weight truck; NA = not applicable; OWT = overweight truck; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart; TCBA = transfer cask buffer 
area; TCRRF = Transportation Cask Receipt/Return Facility. 
The Event Sequence Designator is a unique event sequence index for each event. The prefix identifies the building or facility, for example CWPRB, the middle characters identify an activity, room, or area, for example TCBA, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-12 April 2005 
Table III-4. Disposition of Internal Events That Occur Inside the Canister Handling Facility: Entrance Vestibule (Room 1036), Tools/Parts Storage Room (Room 1035) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. SRTC derailment, overturning, or collision involving a loaded cask 
followed by a load tipover or fall (Rooms 1035 and 1036). 
CHF-EVTSR-CC1 Beyond Category 2 Transportation casks with impact limiters are designed to withstand, without breaching, 
the bounding drops that could occur during cask handling at the repository. A derailment, 
overturning, or collision does not breach a transportation cask. 
Preventive Design 
2. Overturning or collision involving an LWT trailer or an OWT trailer 
holding a cask (Rooms 1035 and 1036). 
CHF-EVTSR-CC2 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC1. Preventive Design 
3. SRTC derailment, overturning, or collision involving a loaded MSC 
followed by a load tipover or fall (Rooms 1035 and 1036). 
CHF-EVTSR-CC3 Beyond Category 2 A design requirement ensures that an SRTC carrying a cask without impact limiters 
(typically only within structures) or site-specific cask does not derail and the cask or sitespecific 
cask does not fall from the SRTC under normal operating conditions or as the 
result of a collision. 
Preventive Design 
4. Collision of an SRTC, an LWT trailer, or OWT trailer carrying a 
loaded cask with the entrance vestibule doors, tool/parts storage 
room doors, or the canister transfer cell shield doors (Rooms 1035 
and 1036). 
CHF-EVTSR-CC4 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC1. Preventive Design 
5. The entrance vestibule doors, tool/parts storage room doors, or the 
canister transfer cell shield doors close on an SRTC, an LWT trailer, 
or an OWT trailer carrying a loaded cask (Rooms 1035 and 1036). 
CHF-EVTSR-CC5 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC1. Preventive Design 
6. Collision of an SRTC carrying a loaded MSC with the entrance 
vestibule doors, tool/parts storage room doors, or the canister 
transfer cell shield doors (Rooms 1035 and 1036). 
CHF-EVTSR-CC6 Beyond Category 2 Design and operational requirements establish speed limits such that a collision with shield 
or airlock doors or other heavy objects would not overturn an SRTC, or site-specific cask 
transporter or cause it to lose its load. 
Preventive Design- 
Procedural 
Safety 
7. The entrance vestibule doors, tool/parts storage room doors, or the 
canister transfer cell shield doors close on an SRTC carrying a 
loaded MSC (Rooms 1035 and 1036). 
CHF-EVTSR-CC7 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
8. Collision of a mobile elevated platform with a cask during removal of 
personnel barriers and impact limiters or during survey activities 
(Room 1036). 
CHF-EVTSR-CC8 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
9. Drop or collision of personnel barriers or impact limiters from the 
entrance vestibule overhead crane onto or against a cask 
(Room 1036). 
CHF-EVTSR-CC9 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety 
10. Collision between a forklift and a cask on an SRTC, an LWT trailer 
or an OWT trailer or the conveyance holding the cask (Room 1036). 
CHF-EVTSR-CC10 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC8. Preventive Procedural 
Safety 
11. Collision between a mobile elevated platform and a cask on an 
SRTC, an LWT trailer or an OWT trailer or the conveyance holding 
the cask (Room 1036). 
CHF-EVTSR-CC11 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC8. Preventive Procedural 
Safety 
12. Collision between a forklift and an MSC on an SRTC or the SRTC 
holding the cask (Room 1036). 
CHF-EVTSR-CC12 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC8. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-13 April 2005 
Table III-4. Disposition of Internal Events That Occur Inside the Canister Handling Facility: Entrance Vestibule (Room 1036), Tools/Parts Storage Room (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
13. Collision between a mobile elevated platform and an MSC on an 
SRTC or the SRTC holding the MSC (Room 1036). 
CHF-EVTSR-CC13 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC8. Preventive Procedural 
Safety 
14. Drop or collision of equipment from the entrance vestibule 
overhead bridge crane (including handling equipment for 
personnel barrier, impact limiters, etc.) onto or against a cask or 
MSC (Room 1036). 
CHF-EVTSR-CC14 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-CC9. Preventive Procedural 
Safety 
Chemical 
Contamination-Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1035 and 1036). 
CHF-EVTSR-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed cask, therefore this event does not occur unless an 
event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible 
outcome of any event that exposes SNF to air. Consequence analyses account for the 
possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a forklift (Room 1036). CHF-EVTSR-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1036). 
CHF-EVTSR-EI2 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-EI1. Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a site prime mover 
(Room 1036). 
CHF-EVTSR-EI3 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the entrance vestibule overhead 
crane (Room 1036). 
CHF-EVTSR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
entrance vestibule electrical equipment (Room 1036). 
CHF-EVTSR-FT2 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-FT1. Preventive Design- 
Procedural 
Safety 
3. Diesel fuel fire/explosion involving a diesel-powered SRTC tractor 
pulling or pushing an SRTC holding a loaded cask or MSC (Room 
1036). 
CHF-EVTSR-FT3 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) involving a site prime mover 
pulling or pushing an LWT or an OWT trailer holding a loaded 
cask (Room 1036). 
CHF-EVTSR-FT4 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-FT1. Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with a forklift 
(Room 1036). 
CHF-EVTSR-FT5 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with a mobile 
elevated platform (Room 1036). 
CHF-EVTSR-FT6 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-FT1. Preventive Design- 
Procedural 
Safety 
7. Transient combustible fire in the entrance vestibule or the 
tools/parts storage room (Rooms 1035 and 1036). 
CHF-EVTSR-FT7 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-14 April 2005 
Table III-4. Disposition of Internal Events That Occur Inside the Canister Handling Facility: Entrance Vestibule (Room 1036), Tools/Parts Storage Room (Room 1035) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1035 and 1036). 
CHF-EVTSR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction 
or other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1035 and 1036). 
CHF-EVTSR-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Radiation-induced damage to a facility SSC (Rooms 1035 and 
1036). 
CHF-EVTSR-R3 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with an SRTC (holding a cask) derailment or 
collision followed by a load tipover or fall and rearrangement of 
the cask internals (Rooms 1035 and 1036). 
CHF-EVTSR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with overturning or collision involving an 
LWT or an OWT trailer holding a cask and rearrangement of cask 
internals (Rooms 1035 and 1036). 
CHF-EVTSR-F2 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-F1. Preventive Design 
3. Criticality associated with an SRTC (holding a loaded MSC) 
derailment or collision followed by a load tipover or fall and 
rearrangement of the cask internals (Rooms 1035 and 1036). 
CHF-EVTSR-F3 Beyond Category 2 Same disposition as Potential Event CHF-EVTSR-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; EI = explosion-implosion; EVTSR = entrance vestibule tools/parts storage room; F = fissile; FT = fire-thermal; HLW = high-level radioactive waste; HVAC = heating, 
ventilation, and air-conditioning; LWT = legal-weight truck; NA = not applicable; OWT = overweight truck; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example CHF, the middle identifies an activity, room, or area, for example EVTSR, and the suffix identifies the hazard category 
and event number, for example CC1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-15 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Slapdown of a cask onto an SRTC, a truck trailer, or the floor 
during upending of the cask to the vertical orientation 
(Room 1033). 
CHF-CTC-CC1A 
CHF-CTC-CC1B 
CHF-CTC-CC1C 
CHF-CTC-CC1D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact limiters 
and site-specific casks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. 
Preventive Design- 
Procedural 
Safety 
2. Drop of a cask from a canister transfer cell overhead crane onto 
the floor during the transfer from an SRTC or truck trailer to the 
cask preparation pit (Room 1033). 
CHF-CTC-CC2A 
CHF-CTC-CC2B 
CHF-CTC-CC2C 
CHF-CTC-CC2D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event CHF-CTC-CC1. Preventive Design- 
Procedural 
Safety 
3. Drop or collision of a cask from a canister transfer cell overhead 
crane onto or against a sharp object during the transfer from an 
SRTC or truck trailer to the cask preparation pit (Room 1033). 
CHF-CTC-CC3 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
4. Drop of a loaded MSC from a canister transfer cell overhead 
crane onto the floor during the transfer from an SRTC to the cask 
preparation pit (Room 1033). 
CHF-CTC-CC4A 
CHF-CTC-CC4B 
CHF-CTC-CC4C 
CHF-CTC-CC4D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event CHF-CTC-CC1. Preventive Design- 
Procedural 
Safety 
5. Drop or collision of a loaded MSC from a canister transfer cell 
overhead crane onto or against a sharp object during the transfer 
from an SRTC to the cask preparation pit (Room 1033). 
CHF-CTC-CC5 Beyond Category 2 Same disposition as Potential Event CHF-CTC-CC3. Preventive Design- 
Procedural 
Safety 
6. Drop or collision of a cask from a canister transfer cell overhead 
crane into or against the cask preparation pit or an MSC/WP 
loading pit during the transfer from an SRTC or truck trailer to the 
cask preparation pit (Room 1033). 
CHF-CTC-CC6A 
CHF-CTC-CC6B 
CHF-CTC-CC6C 
CHF-CTC-CC6D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event CHF-CTC-CC1. For collisions, a design 
requirement limits speed for crane transfers such that a collision at the maximum speed 
could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval canister, 
or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
7. Drop or collision of a loaded MSC from a canister transfer cell 
overhead crane into or against the cask preparation pit or an 
MSC/WP loading pit during the transfer from the SRTC to the 
cask preparation pit (Room 1033). 
CHF-CTC-CC7A 
CHF-CTC-CC7B 
CHF-CTC-CC7C 
CHF-CTC-CC7D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event CHF-CTC-CC1. For collisions, 
a design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-16 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Slapdown of a cask or MSC in the pit area due to off-center cask 
or MSC lowering into the cask preparation pit and followed by a 
cask or MSC corner drop onto the edge of the pit and slapdown 
(Room 1033). 
CHF-CTC-CC8A 
CHF-CTC-CC8B 
CHF-CTC-CC8C 
CHF-CTC-CC8D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event CHF-CTC-CC1. Preventive Design- 
Procedural 
Safety 
9. Drop or collision involving the pit moveable platform onto or 
against a cask or MSC in the cask preparation pit (Room 1033). 
CHF-CTC-CC9 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
10.Handling equipment drop onto or against a cask or MSC (Room 
1033). 
CHF-CTC-CC10 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety 
11.Drop of a cask or MSC outer lid from a canister transfer cell 
overhead crane onto a cask or MSC inner lid, as applicable 
(Room 1033). 
CHF-CTC-CC11A 
CHF-CTC-CC11B 
CHF-CTC-CC11C 
CHF-CTC-CC11D 
CHF-CTC-CC11E 
CHF-CTC-CC11F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
12.Drop of a cask or MSC inner lid from a canister transfer cell 
overhead crane onto a canister inside the cask or MSC, as 
applicable (Room 1033). 
CHF-CTC-CC12A 
CHF-CTC-CC12B 
CHF-CTC-CC12C 
CHF-CTC-CC12D 
CHF-CTC-CC12E 
CHF-CTC-CC12F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Same disposition as Potential Event CHF-CTC-CC11. Preventive Design- 
Procedural 
Safety 
13.Drop or collision of tools or handling equipment (including the 
outer lid-lifting fixture, inner lid-lifting fixture, etc.) onto or against 
a cask or MSC outer lid or a cask or MSC inner lid, as applicable 
(Room 1033). 
CHF-CTC-CC13 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, can 
not initiate an event sequence if dropped onto or collided against (1) a transportation cask 
or site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
14. Drop or collision of tools or handling equipment, including a lift 
fixture with pintle or a shield ring, onto or against a canister 
inside an open cask or MSC (Room 1033). 
CHF-CTC-CC14A 
CHF-CTC-CC14B 
CHF-CTC-CC14C 
CHF-CTC-CC14D 
CHF-CTC-CC14E 
CHF-CTC-CC14F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) In this potential event, a drop has to occur to cause a collision because the 
equipment would be suspended above the canister. Design and operational requirements 
reduce the drop probability. An operational requirement ensures the establishment of a 
maximum lift height limit for handling equipment suspended above DOE SNF canisters. A 
design requirement ensures that the handling equipment is not capable of causing an 
event sequence due to a breach of a DOE SNF canister if dropped from within the liftheight 
limit. Design and operational requirements limit the probability of exceeding the lift 
height. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-17 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
15. Drop of a canister from a canister transfer cell overhead crane 
back into the cask or MSC being unloaded (including a naval 
SNF canister, a DOE SNF MCO, a DPC, a DOE HLW canister, 
or a [standardized] DOE SNF canister) (Room 1033). 
CHF-CTC-CC15A 
CHF-CTC-CC15B 
CHF-CTC-CC15C 
CHF-CTC-CC15D 
CHF-CTC-CC15E 
CHF-CTC-CC15F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Design and operational requirements reduce the drop probability. A design 
requirement limits lift heights for DOE SNF canisters, DOE HLW canisters, naval canisters, 
DPCs, and DOE SNF multicanister overpacks. Design and operational requirements limit 
the probability of exceeding the lift height. Design requirements ensures that standardized 
DOE SNF canisters would withstand without breach a drop of another standardized DOE 
SNF canister and that MCOs would withstand without breach a drop of another MCO 
dropped from within its lift-height limits. Canister design requirements and the reliability of 
fabrication processes limit the probability that a DOE SNF canister or DOE multicanister 
overpack is defective. Operational controls render dropping a DOE SNF canister on a DOE 
HLW canister Beyond Category 2. A design requirement ensures that a DOE SNF canister 
in a cask, WP, staging rack, or staging pit would withstand without breach the drop of a 
DOE HLW canister on top of the DOE SNF canister from within their lift height limits. 
Neither naval canisters nor MCOs are staged in staging racks. 
Preventive Design- 
Procedural 
Safety 
16. Drop or collision of a DOE HLW canister or a [standardized] 
DOE SNF canister from a canister transfer cell overhead crane 
onto or against another [standardized] DOE SNF canister, or 
DOE HLW canister in the cask being unloaded, as applicable 
(Room 1033). 
CHF-CTC-CC16A 
CHF-CTC-CC16B 
CHF-CTC-CC16C 
CHF-CTC-CC16D 
CHF-CTC-CC16E 
CHF-CTC-CC16F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC15. For collisions, a 
design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
17. Horizontal movement of a canister before it is fully vertically 
lifted out of a cask or MSC (Room 1033). 
CHF-CTC-CC17 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
18. Drop of a canister from a canister transfer cell overhead crane 
onto the cell floor or other flat object during transfer from the 
cask or MSC to a WP or an MSC, as applicable, or during 
transfer to a canister staging pit (Room 1033). 
CHF-CTC-CC18A 
CHF-CTC-CC18B 
CHF-CTC-CC18C 
CHF-CTC-CC18D 
CHF-CTC-CC18E 
CHF-CTC-CC18F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC15. Preventive Design- 
Procedural 
Safety 
19. Drop or collision of a canister from a canister transfer cell 
overhead crane onto or against a sharp object during transfer 
from the cask or MSC to a WP or an MSC, as applicable, or 
during transfer to a canister staging pit (Room 1033). 
CHF-CTC-CC19 Beyond Category 2 Same disposition as Potential Event CHF-CTC-CC3. Preventive Design- 
Procedural 
Safety 
20. Slapdown of a canister in an MSC/WP loading pit or the pit 
areas due to off-center canister lowering into the WP or MSC, 
followed by a canister corner drop onto the edge of the pit and 
slapdown (Room 1033). 
CHF-CTC-CC20A 
CHF-CTC-CC20B 
CHF-CTC-CC20C 
CHF-CTC-CC20D 
CHF-CTC-CC20E 
CHF-CTC-CC20F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC15. Preventive Design- 
Procedural 
Safety 
21. Drop or collision of a DPC, DOE HLW canister, or 
[standardized] DOE SNF canister from a canister transfer cell 
overhead crane into or against the empty MSC being loaded 
(Room 1033). 
CHF-CTC-CC21A 
CHF-CTC-CC21B 
CHF-CTC-CC21C 
CHF-CTC-CC21D 
CHF-CTC-CC21E 
CHF-CTC-CC21F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC16. For collisions, a 
design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-18 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
22. Drop or collision of a naval SNF canister, a DOE HLW canister, 
a DOE SNF MCO, or a [standardized] DOE SNF canister from a 
canister transfer cell overhead crane into or against the WP 
being loaded (Room 1033). 
CHF-CTC-CC22A 
CHF-CTC-CC22B 
CHF-CTC-CC22C 
CHF-CTC-CC22D 
CHF-CTC-CC22E 
CHF-CTC-CC22F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC16. Preventive Design- 
Procedural 
Safety 
23. Drop or collision of a DOE HLW canister from a canister 
transfer cell overhead crane onto or another DOE HLW 
canister, a DOE SNF MCO, or a [standardized] DOE SNF 
canister in a WP (Room 1033). 
CHF-CTC-CC23A 
CHF-CTC-CC23B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
24. Drop or collision of a DOE HLW canister from a canister 
transfer cell overhead crane onto or against another DOE HLW 
canister or a [standardized] DOE SNF canister in an MSC 
(Room 1033). 
CHF-CTC-CC24A 
CHF-CTC-CC24B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event CHF-CTCCC23. 
Preventive Design- 
Procedural 
Safety 
25. Drop or collision of a [standardized] DOE SNF canister from a 
canister transfer cell overhead crane onto or against a DOE 
HLW canister in a WP or MSC (Room 1033). 
CHF-CTC-CC25C 
CHF-CTC-CC25D 
CHF-CTC-CC25E 
CHF-CTC-CC25F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event CHF-CTCCC16. 
Preventive Design- 
Procedural 
Safety 
26. Drop or collision of a DOE SNF MCO from a canister transfer 
cell overhead crane onto or against another DOE SNF MCO or 
onto a DOE HLW canister in a WP (Room 1033). 
CHF-CTC-CC26C 
CHF-CTC-CC26D 
CHF-CTC-CC26E 
CHF-CTC-CC26F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event CHF-CTCCC16. 
Preventive Design- 
Procedural 
Safety 
27. Drop or collision of a DOE SNF MCO from a canister transfer 
cell overhead crane onto or against a [standardized] DOE SNF 
canister or a drop of a [standardized] DOE SNF canister onto or 
against another [standardized] DOE SNF canister in a WP due 
to a misload (Room 1033). 
CHF-CTC-CC27C 
CHF-CTC-CC27D 
CHF-CTC-CC27E 
CHF-CTC-CC27F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event CHF-CTCCC16.. 
Preventive Design- 
Procedural 
Safety 
28. Drop or collision of a DOE SNF MCO from a canister transfer 
cell overhead crane onto or against a [standardized] DOE SNF 
canister or onto or against a DOE HLW canister or another 
misloaded DOE SNF MCO in an MSC due to a misload (Room 
1033). 
CHF-CTC-CC28C 
CHF-CTC-CC28D 
CHF-CTC-CC28E 
CHF-CTC-CC28F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event CHF-CTCCC16. 
Preventive Design- 
Procedural 
Safety 
29. Drop or collision of a DOE HLW canister or a [standardized] 
DOE SNF canister from a canister transfer cell overhead crane 
into or against a canister staging pit (Room 1033). 
CHF-CTC-CC29A 
CHF-CTC-CC29B 
CHF-CTC-CC29C 
CHF-CTC-CC29D 
CHF-CTC-CC29E 
CHF-CTC-CC29F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC16. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-19 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
30. Slapdown of a DOE HLW canister or a [standardized] DOE 
SNF canister in the staging pit area due to off-center canister 
lowering into the pit and followed by a canister corner drop 
onto the edge of the staging pit and a slapdown (Room 1033). 
CHF-CTC-CC30A 
CHF-CTC-CC30B 
CHF-CTC-CC30C 
CHF-CTC-CC30D 
CHF-CTC-CC30E 
CHF-CTC-CC30F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC15. Preventive Design- 
Procedural 
Safety 
31. Drop or collision of a DOE HLW canister or a [standardized] 
DOE SNF canister from a canister transfer cell overhead crane 
onto or against the top of another DOE HLW canister or 
[standardized] DOE SNF canister in a canister staging pit 
(Room 1033). 
CHF-CTC-CC31A 
CHF-CTC-CC31B 
CHF-CTC-CC31C 
CHF-CTC-CC31D 
CHF-CTC-CC31E 
CHF-CTC-CC31F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event CHF-CTC-CC16. Preventive Design- 
Procedural 
Safety 
32. Impact due to horizontal movement of a canister before it is fully 
vertically lifted out of a canister staging pit (Room 1033). 
CHF-CTC-CC32 Beyond Category 2 Same disposition as Potential Event CHF-CTC-CC17. Preventive Design 
33. Drop of or collision of handling equipment onto or against a 
DOE HLW canister or a [standardized] DOE SNF canister in a 
canister staging pit (Room 1033). 
CHF-CTC-CC33A 
CHF-CTC-CC33B 
CHF-CTC-CC33C 
CHF-CTC-CC33D 
CHF-CTC-CC33E 
CHF-CTC-CC33F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) Same disposition as Potential Event CHF-CTC-CC14. Preventive Design- 
Procedural 
Safety 
34. Drop of or collision of a canister staging pit shield plug onto or 
against a canister in the canister staging pit (Room 1033). 
CHF-CTC-CC34 Beyond Category 2 A design requirement ensures that the shield plugs for the canister staging pits or racks do 
not fit far enough into the opening to breach a canister inside the pit if the shield plug 
is dropped. 
Preventive Design 
35. Drop or collision involving the pit moveable platform onto or 
against a loaded MSC in an MSC/WP loading pit (Room 1033). 
CHF-CTC-CC35 Beyond Category 2 Same disposition as Potential Event CHF-CTC-CC9. Preventive Procedural 
Safety 
36. Drop of a WP inner lid into an open, loaded WP (Room 1033). CHF-CTC-CC36A 
CHF-CTC-CC36B 
CHF-CTC-CC36C 
CHF-CTC-CC36D 
CHF-CTC-CC36E 
CHF-CTC-CC36F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Same disposition as Potential Event CHF-CTC-CC11. Preventive Design- 
Procedural 
Safety 
37. Drop of the MSC lid into an open, loaded MSC (Room 1033). CHF-CTC-CC37A 
CHF-CTC-CC37B 
CHF-CTC-CC37C 
CHF-CTC-CC37D 
CHF-CTC-CC37E 
CHF-CTC-CC37F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Same disposition as Potential Event CHF-CTC-CC11. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-20 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
38. Drop or collision of tools or handling equipment into or against 
an open, loaded or partially loaded, WP (Room 1033). 
CHF-CTC-CC38A 
CHF-CTC-CC38B 
CHF-CTC-CC38C 
CHF-CTC-CC38D 
CHF-CTC-CC38E 
CHF-CTC-CC38F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) Same disposition as Potential Event CHF-CTC-CC14. Preventive Design- 
Procedural 
Safety 
39. Drop or collision of tools or handling equipment into or against 
an open, loaded or partially loaded MSC (Room 1033). 
CHF-CTC-CC39A 
CHF-CTC-CC39B 
CHF-CTC-CC39C 
CHF-CTC-CC39D 
CHF-CTC-CC39E 
CHF-CTC-CC39F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) Same disposition as Potential Event CHF-CTC-CC14. Preventive Design- 
Procedural 
Safety 
40. Drop or collision of tools or equipment (including a lid-lifting 
fixture) onto or against a loaded WP inner lid (Room 1033). 
CHF-CTC-CC40 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
41. Drop or collision of tools or equipment (including a lid-lifting 
fixture) onto or against the lid of a loaded, unsealed or sealed 
MSC (Room 1033). 
CHF-CTC-CC41 Beyond Category 2 Same disposition as Potential Event CHF-CTC-CC13. Preventive Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1033). 
CHF-CTC-CCF1 NAAccounted for in 
consequence 
analyses, if 
applicable 
NASNF is contained inside a sealed canister, therefore this event does not occur unless 
an event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a 
possible outcome of any event that exposes SNF to air. Consequence analyses account 
for the possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Cask sampling and purging system or decontamination (or other 
pneumatic or pressurized system) missile due to a fractured 
nozzle/valve stem/pneumatic device (Room 1033). 
CHF-CTC-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the cask sampling and purging 
system and the ignition of hydrogen that may have accumulated 
in the cask or MSC (Room 1033). 
CHF-CTC-EI2 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a forklift (Room 1033). CHF-CTC-EI3 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
4. Hydrogen explosion involving batteries on a site prime mover 
(Room 1033). 
CHF-CTC-EI4 Beyond Category 2 Same disposition as Potential Event CHF-CTC-EI3. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-21 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Fire-Thermal 1. Electrical fire associated with the canister transfer cell overhead 
cranes (Room 1033). 
CHF-CTC-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
canister transfer cell electrical equipment (Room 1033). 
CHF-CTC-FT2 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT1. Preventive Design- 
Procedural 
Safety 
3. Diesel fuel fire/explosion on an SRTC tractor pushing an SRTC 
holding a loaded cask into the canister transfer cell (Room 1033). 
CHF-CTC-FT3 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) involving a site prime mover 
pulling or pushing an LWT or an OWT trailer holding a loaded 
cask (Room 1033). 
CHF-CTC-FT4 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT1. Preventive Design- 
Procedural 
Safety 
5. Diesel fuel fire/explosion associated with the SRTC tractor 
pushing an SRTC holding an MSC (Room 1033). 
CHF-CTC-FT5 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with a forklift 
(Room 1033). 
CHF-CTC-FT6 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT1. Preventive Design- 
Procedural 
Safety 
7. High-efficiency particulate air (HEPA) filter fire due to excessive 
radioactive decay within the filter bed (Room 1033). 
CHF-CTC-FT7 Beyond Category 2 Operation requirements ensure that the operating surface temperatures of high-efficiency 
particulate air (HEPA) filters is maintained such that they can not catch on fire under 
normal operation or in the event of a shutdown of the HVAC system. 
Preventive Procedural 
Safety 
8. Canister overheating in the canister staging pit due to a loss of 
cooling resulting in excessive temperature and possible damage 
to canister contents and/or confinement (Room 1033). 
CHF-CTC-FT8 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
9. Transient combustible fire in the canister transfer cell 
(Room 1033). 
CHF-CTC-FT9 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT1. Preventive Design- 
Procedural 
Safety 
10.Overheating of a loaded cask, WP, or MSC while staged in a pit 
due to a loss of cooling resulting in excessive temperature and 
possible damage to canister contents (Room 1033). 
CHF-CTC-FT10 Beyond Category 2 Same disposition as Potential Event CHF-CTC-FT8. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1033). 
CHF-CTC-R1 NAAccounted for in 
consequence 
analyses, if 
applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction 
or other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1033). 
CHF-CTC-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-22 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Damage or rupture of cask sampling and purging system, 
leading to a release of cask internal gasses and radioactive 
material (Room 1033). 
CHF-CTC-R3 Normal Operations The sampling operation is conducted so that exposure of workers to radiation is managed 
as a normal-operations dose by procedures for monitoring radiation doses and assigning 
work, which ensure that workers do not receive excessive radiation doses. Although a 
rupture leading to a radiological release would be an off-normal occurrence, any release 
and related dose would be managed as part of routine radiation protection operations. 
Mitigative Procedural 
Safety 
4. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Room 
1033). 
CHF-CTC-R4 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting exposure of workers to radiation is managed as a normal-operations dose by 
procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
5. Inadvertent opening of a canister transfer cell shield door or a 
cask preparation pit cover or an MSC/WP pit cover, leading to a 
worker exposure (Room 1033). 
CHF-CTC-R5 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
6. Radiation-induced damage to a facility SSC (Room 1033). CHF-CTC-R6 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a drop or slapdown of a loaded cask 
from a canister transfer cell overhead crane and a 
rearrangement of cask internals (Room 1033). 
CHF-CTC-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a drop or slapdown of a loaded MSC 
from a canister transfer cell overhead crane and a 
rearrangement of cask internals (Room 1033). 
CHF-CTC-F2 Beyond Category 2 Same disposition as Potential Event CHF-CTC-F1. Preventive Design- 
3. Criticality associated with a drop or slapdown of a loaded WP 
(unsealed) from a canister transfer cell overhead crane and a 
rearrangement of WP internals (Room 1033). 
CHF-CTC-F3 Beyond Category 2 A design requirement ensures that an unsealed WP that is dropped onto an essentially 
unyielding surface from within its lift-height limits would not spill its contents. A design 
requirement ensures that waste packages are designed to preclude criticality with credit for 
moderator control and without credit for burnup. Demonstration of compliance must 
account for the bowing of fuel rods or other rearrangement of fissile material that may 
occur due to a drop or other handling incident. Design and operational requirements 
ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
4. Criticality associated with a drop or slapdown of a [standardized] 
DOE SNF canister, a naval SNF canister, a DOE SNF MCO, a 
DPC, or a DOE HLW canister and a rearrangement of canister 
internals (Room 1033). 
CHF-CTC-F4 Beyond Category 2 Same disposition as Potential Event CHF-CTC-F1. Additionally, a design requirement 
ensures that dropping a DOE SNF canister within its design basis does not lead to a 
criticality. Demonstration of compliance for the staging rack must account for the most 
reactive configuration of DOE SNF canisters with credit for moderator control. There is no 
potential for criticality of DOE HLW canisters. Criticality of a naval canister following a 
drop, or other impact event, has been evaluated to be Beyond Category 2 based upon 
probabilities of independent events required for criticality. Design and operational 
requirements ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
5. Criticality associated with a misload of a WP or an MSC (Room 
1033). 
CHF-CTC-F5 Beyond Category 2 Same disposition as Potential Event CHF-CTC-F1. Additionally, a design requirement 
ensures that criticality caused by a misload of a waste package is not credible because 
waste packages can be loaded with canisters that are acceptable for disposal without 
leading to a preclosure nuclear criticality with credit for moderator control. Design and 
operational requirements ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
6. Criticality associated with a misload of a canister staging pit 
(Room 1033). 
CHF-CTC-F6 Beyond Category 2 A design requirement ensures that the most reactive configuration of standardized DOE 
SNF canisters can be loaded into canister staging pits or racks with credit for moderator 
control without causing a nuclear criticality. Neither naval canisters nor MCOs are staged in 
staging racks. There is no potential for criticality of DOE HLW canisters. Design and 
operational requirements ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-23 April 2005 
Table III-5. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Canister Transfer): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
7. Criticality associated with a drop of heavy equipment onto an 
unsealed, loaded cask, WP, or MSC and a rearrangement of the 
container internals (Room 1033). 
CHF-CTC-F7 Beyond Category 2 Same disposition as Potential Events CHF-CTC-F1 and CHF-CTC-F3. Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; CTC = canister transfer cell; DBGM = design basis ground motion; DOE = U.S. Department of Energy; EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = 
generalized event tree; HLW = high-level radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example CHF, the middle identifies an activity, room, or area, for example CTC, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-24 April 2005 
Table III-6. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Transfer to Waste Package Closure, Site-specific Cask Closure and Removal): Canister Transfer Cell (Room 1033) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Drop or collision of handling equipment or a lifting fixture onto or 
against a loaded WP inner lid (Room 1033). 
CHF-WPTC-CC1 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
2. Drop or collision of handling equipment or a lifting fixture onto or 
against a loaded MSC lid (Room 1033). 
CHF-WPTC-CC2 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, does 
not initiate an event sequence if dropped onto or collided against (1) a transportation cask 
or site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid 
in place. 
Preventive Procedural 
Safety 
3. Impact due to horizontal movement of a loaded WP by a canister 
transfer cell overhead crane before it is fully lifted vertically out of 
the MSC/WP loading pit (Room 1033). 
CHF-WPTC-CC3 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
4. Drop or collision of an unsealed, loaded WP from a canister 
transfer cell overhead crane back into or against the MSC/WP 
loading pit (Room 1033). 
CHF-WPTC-CC4A 
CHF-WPTC-CC4B 
CHF-WPTC-CC4C 
CHF-WPTC-CC4D 
CHF-WPTC-CC4E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Design and operational requirements reduce the drop probability. Design 
and operational requirements specify lift-height limits for unsealed waste packages 
whenever waste packages are transferred. If the limit can not be met, impact absorbers 
are provided. Design and operational requirements limit the probability of exceeding the 
lift-height limit. Canister design requirements and the reliability of fabrication processes 
limit the probability that a DOE SNF canister or DOE multicanister overpack is defective. 
For collisions, a design requirement limits speed for crane transfers such that a collision at 
the maximum speed could not breach an MSC, transportation cask, transfer cask, DPC, 
DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
5. Drop of an unsealed, loaded WP from a canister transfer cell 
overhead crane onto the cell floor or a pit cover during the lift and 
transfer to the WP positioning cell pedestal and trolley(Room 
1033). 
CHF-WPTC-CC5A 
CHF-WPTC-CC5B 
CHF-WPTC-CC5C 
CHF-WPTC-CC5D 
CHF-WPTC-CC5E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event CHF-WPTC-CC4. Additionally, a 
design requirement ensures that pit covers for the waste-package and MSC pits are sturdy 
enough to prevent a WP or MSC that is dropped on the pit cover from penetrating the pit 
cover and falling into the pit. 
Preventive Design- 
Procedural 
Safety 
6. Drop or collision of an unsealed, loaded WP from a canister 
transfer cell overhead crane onto or against a sharp object during 
the lift and transfer to the WP positioning cell pedestal and 
trolley(Room 1033). 
CHF-WPTC-CC6 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-25 April 2005 
Table III-6. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Transfer to Waste Package Closure, Site-specific Cask Closure and Removal): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
7. Slapdown of a loaded, unsealed WP onto the cell floor, into a 
wall, or onto a pit cover following a drop from a canister transfer 
cell overhead crane onto the edge of the trolley, a pit edge, or pit 
cover during the lift and transfer to the WP positioning cell 
pedestal and trolley (Room 1033). 
CHF-WPTC-CC7A 
CHF-WPTC-CC7B 
CHF-WPTC-CC7C 
CHF-WPTC-CC7D 
CHF-WPTC-CC7E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event CHF-WPTC-CC5. Preventive Design- 
Procedural 
Safety 
8. Drop or collision of an unsealed, loaded WP from a canister 
transfer cell overhead crane onto or against a loaded or partially 
loaded MSC or WP (with no lid in place) in an MSC/WP loading 
pit (with no pit cover in place) during the lift and transfer to the 
WP positioning cell pedestal and trolley (Room 1033). 
CHF-WPTC-CC8 Beyond Category 2 An operational requirement ensures that a loaded waste package is not carried over a 
loaded site-specific cask/waste package in a loading pit. An operational requirement 
ensures that covers for the waste-package and site-specific cask pits are replaced 
whenever individual waste-form handling operations are suspended unless loading 
operation in that particular pit is complete and the next operation involving the overhead 
crane is to remove the waste package or site-specific cask from the pit. 
Preventive Procedural 
Safety 
9. Drop or collision of an unsealed, loaded WP from a canister 
transfer cell overhead crane onto or against a loaded MSC or WP 
(with lid in place) in an MSC/WP loading pit (with no pit cover in 
place) during the lift and transfer to the WP positioning cell 
pedestal and trolley (Room 1033). 
CHF-WPTC-CC9 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-CC8. Preventive Procedural 
Safety 
10.Drop or collision of an unsealed, loaded WP from a canister 
transfer cell overhead crane onto or against a loaded, unsealed 
WP on the opposite WP positioning cell pedestal and trolley 
during the lift and transfer to a WP positioning cell pedestal and 
trolley (Room 1033). 
CHF-WPTC-CC10 Beyond Category 2 An operational requirement ensures that whenever a waste-package trolley is being loaded 
onto a trolley or is already on the trolley but not in the waste package positioning cell, the 
opposite trolley remains in its positioning cell or is otherwise out of the way. A design 
requirement limits speed for crane transfers such that a collision at the maximum speed 
could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval canister, 
or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
11.Drop or collision of an unsealed, loaded WP from a canister 
transfer cell overhead crane onto or against a loaded, sealed WP 
on the opposite WP positioning cell pedestal and trolley during 
the lift and transfer to a WP positioning cell pedestal and 
trolley(Room 1033). 
CHF-WPTC-CC11 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-CC10. Preventive Design- 
Procedural 
Safety 
12.Slapdown of a loaded, unsealed WP onto the floor and then 
across or into an empty MSC/WP loading pit (with no pit cover in 
place) following a drop from a canister transfer cell overhead 
crane onto the edge of the trolley or pit edge during the lift and 
transfer to the WP positioning cell pedestal and trolley 
(Room 1033). 
CHF-WPTC-CC12A 
CHF-WPTC-CC12B 
CHF-WPTC-CC12C 
CHF-WPTC-CC12D 
CHF-WPTC-CC12E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event CHF-WPTC-CC4. Preventive Design- 
Procedural 
Safety 
13.Slapdown of a loaded, unsealed WP onto the floor and then 
across or into an MSC/WP loading pit (with no pit cover in place 
and a loaded or partially loaded, sealed or unsealed MSC or WP 
in place) following a drop from a canister transfer cell overhead 
crane onto the edge of the trolley or pit edge during the lift and 
transfer to the WP positioning cell pedestal and trolley 
(Room 1033). 
CHF-WPTC-CC13A 
CHF-WPTC-CC13B 
CHF-WPTC-CC13C 
CHF-WPTC-CC13D 
CHF-WPTC-CC13E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event CHF-WPTC-CC4. Additionally, 
operational requirements cited in the disposition of Potential Event CHF-WPTC-CC8 
preclude a drop into an occupied loading pit. 
Preventive Design- 
Procedural 
Safety 
14.Slapdown of a loaded, unsealed WP that subsequently impacts a 
loaded, unsealed WP on the opposite WP positioning cell trolley 
following a drop from a canister transfer cell overhead crane onto 
the edge of the opposite WP positioning cell trolley, a pit edge, or 
other object during the lift and transfer to the WP positioning cell 
pedestal and trolley (Room 1033). 
CHF-WPTC-CC14 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-CC10. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-26 April 2005 
Table III-6. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Transfer to Waste Package Closure, Site-specific Cask Closure and Removal): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
15.Slapdown of a loaded, unsealed WP that subsequently impacts a 
loaded, sealed WP on the opposite WP positioning cell trolley 
following a drop from a canister transfer cell overhead crane onto 
the edge of the WP positioning cell trolley, a pit edge, or other 
object during the lift and transfer to the WP positioning cell 
pedestal and trolley (Room 1033). 
CHF-WPTC-CC15 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-CC10. Preventive Design- 
Procedural 
Safety 
16.Impact due to horizontal movement of a loaded, sealed MSC by a 
canister transfer cell overhead crane before it is fully vertically 
lifted out of the MSC/WP loading pit (Room 1033). 
CHF-WPTC-CC16 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-CC3. Preventive Design 
17.Drop or collision of a loaded, sealed MSC from a canister transfer 
cell overhead crane back into or against the MSC/WP loading pit 
during MSC removal and transfer to the SRTC (Room 1033). 
CHF-WPTC-CC17A 
CHF-WPTC-CC17B 
CHF-WPTC-CC17C 
CHF-WPTC-CC17D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Design and operational requirements reduce the drop probability. 
Design and operational requirements limit the lift height for transportation and transfer 
casks without impact limiters and site-specific casks. Design and operational requirements 
limit the probability of exceeding the lift height. Canister design requirements and the 
reliability of fabrication processes limit the probability that a DOE SNF canister or DOE 
multicanister overpack is defective. For collisions, a design requirement limits speed for 
crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
18.Slapdown of a loaded, sealed MSC onto the cell floor, into a wall, 
or onto a pit cover following a drop from a canister transfer cell 
overhead crane onto the edge of the MSC/WP loading pit or the 
SRTC during MSC removal from the pit and transfer to the SRTC 
(Room 1033). 
CHF-WPTC-CC18A 
CHF-WPTC-CC18B 
CHF-WPTC-CC18C 
CHF-WPTC-CC18D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event CHF-WPTC-CC17. Preventive Design- 
Procedural 
Safety 
19. Drop or collision of a loaded, sealed MSC from a canister transfer 
cell overhead crane onto or against the SRTC following removal 
of the MSC from the MSC/WP loading pit during transfer to the 
SRTC for removal from the building (Room 1033). 
CHF-WPTC-CC19A 
CHF-WPTC-CC19B 
CHF-WPTC-CC19C 
CHF-WPTC-CC19D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event CHF-WPTC-CC17. For 
collisions, a design requirement limits speed for crane transfers such that a collision at the 
maximum speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE 
or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
20. Drop of a loaded, sealed MSC from a canister transfer cell 
overhead crane onto the canister transfer cell floor or a pit cover 
following removal of the MSC from the MSC/WP loading pit 
(Room 1033). 
CHF-WPTC-CC20A 
CHF-WPTC-CC20B 
CHF-WPTC-CC20C 
CHF-WPTC-CC20D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event CHF-WPTC-CC17. 
Additionally, a design requirement ensure that pit covers for the waste-package and MSC 
pits are sturdy enough to prevent a WP or MSC that is dropped on the pit cover from 
penetrating the pit cover and falling into the pit. 
Preventive Design- 
Procedural 
Safety 
21.Drop or collision of a loaded, sealed MSC from a canister transfer 
cell overhead crane onto or against a sharp object following 
removal of the MSC from the MSC/WP loading pit (Room 1033). 
CHF-WPTC-CC21 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-CC6. Preventive Design- 
Procedural 
Safety 
22. Collision of the SRTC (holding a loaded, sealed MSC) with the 
entrance vestibule doors, the tool/parts storage room doors, or 
the canister transfer cell shield doors (Room 1033). 
CHF-WPTC-CC22 Beyond Category 2 Design and operational requirements establish speed limits such that a collision with shield 
or airlock doors or other heavy objects would not overturn an SRTC, or site-specific cask 
transporter or cause it to lose its load. 
Preventive Design- 
Procedural 
Safety 
23.The entrance vestibule doors, the tool/parts storage room doors, 
or the canister transfer cell shield doors close on the SRTC 
holding a loaded, sealed MSC (Room 1033). 
CHF-WPTC-CC23 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-27 April 2005 
Table III-6. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Transfer to Waste Package Closure, Site-specific Cask Closure and Removal): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1033). 
CHF-WPTC-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed canister, therefore this event does not occur unless 
an event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a 
possible outcome of any event that exposes SNF to air. Consequence analyses account 
for the possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. MSC inerting system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Room 1033). 
CHF-WPTC-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the canister transfer cell overhead 
cranes (Room 1033). 
CHF-WPTC-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
canister transfer cell electrical equipment (Room 1033). 
CHF-WPTC-FT2 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-FT1. Preventive Design- 
Procedural 
Safety 
3. Diesel fuel fire/explosion associated with the SRTC tractor pulling 
an SRTC holding an MSC (Room 1033). 
CHF-WPTC-FT3 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-FT1. Preventive Design- 
Procedural 
Safety 
4. HEPA filter fire due to excessive radioactive decay within the filter 
bed (Room 1033). 
CHF-WPTC-FT4 Beyond Category 2 Operation requirements ensure that the operating surface temperatures of high-efficiency 
particulate air (HEPA) filters is maintained such that they can not catch on fire under 
normal operation or in the event of a shutdown of the HVAC system. 
Preventive Procedural 
Safety 
5. Transient combustible fire in the canister transfer cell 
(Room 1033). 
CHF-WPTC-FT5 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-FT1. Preventive Design- 
Procedural 
Safety 
6. Thermal hazard (from decay heat) associated with a vertical 
orientation of a non-inerted, loaded, unsealed WP with normal 
cooling (Room 1033). 
CHF-WPTC-FT6 NAAccounted for in 
consequence 
analyses, if applicable 
Same disposition as Potential Event CHF-WPTC-CCF1. NA NA 
7. Overheating of a loaded, unsealed (and uninerted) WP or MSC 
due to a loss of cooling resulting in excessive temperature and 
possible damage to canister contents (Room 1033). 
CHF-WPTC-FT7 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1033). 
CHF-WPTC-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction 
or other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1033). 
CHF-WPTC-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-28 April 2005 
Table III-6. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Transfer to Waste Package Closure, Site-specific Cask Closure and Removal): Canister Transfer Cell (Room 1033) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Inadvertent opening of a canister transfer cell shield door or a WP 
positioning cell shield door, leading to a worker exposure 
(Room 1033). 
CHF-WPTC-R3 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
4. Radiation-induced damage to a facility SSC (Room 1033). CHF-WPTC-R4 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a drop or slapdown of a loaded MSC 
from a canister transfer cell overhead crane and a rearrangement 
of cask internals (Room 1033). 
CHF-WPTC-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with an SRTC (holding a loaded MSC) 
derailment or collision followed by a load tipover or fall and 
rearrangement of the cask internals (Room 1033). 
CHF-WPTC-F2 Beyond Category 2 Same disposition as Potential Event CHF-WPTC-F1. Preventive Design 
3. Criticality associated with a drop or slapdown of a loaded, 
unsealed WP from a canister transfer cell overhead crane and a 
rearrangement of WP internals (Room 1033). 
CHF-WPTC-F3 Beyond Category 2 A design requirement ensures that an unsealed WP that is dropped onto an essentially 
unyielding surface from within its lift-height limits would not spill its contents. A design 
requirement ensures that waste packages are designed to preclude criticality with credit for 
moderator control and without credit for burnup. Demonstration of compliance must 
account for the bowing of fuel rods or other rearrangement of fissile material that may 
occur due to a drop or other handling incident. An unsealed waste package remains 
subcritical with credit for moderator control. Design and operational requirements ensure 
that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
4. Criticality associated with a drop of heavy equipment onto an 
unsealed, loaded WP or MSC and a rearrangement of the 
container internals (Room 1033). 
CHF-WPTC-F4 Beyond Category 2 Same disposition as Potential Events CHF-WPTC-F1 and CHF-WPTC-F3. Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; NA = not applicable; R = radiation; SNF = 
spent nuclear fuel; SRTC = site rail transfer cart; WPTC = waste package transfer to waste package closure. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example CHF, the middle identifies an activity, room, or area, for example WPTC, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-29 April 2005 
Table III-7. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Closure): Waste Package Positioning Cells (Rooms 1011 and 1042), and Closure Cells (Rooms 2010 and 2032) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a loaded, unsealed WP followed by 
a load tipover or fall. (Rooms 1011 and 1042). 
CHF-WPC-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Drop or collision of equipment from a canister transfer cell 
overhead crane onto or against a loaded, unsealed WP positioned 
on a pedestal on a trolley (Rooms 2010 and 2032). 
CHF-WPC-CC2 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
3. Collision involving the trolley holding the loaded, unsealed WP 
and the shield doors between the canister transfer cell and the 
WP positioning cell (Rooms 1011 and 1042). 
CHF-WPC-CC3 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
4. Shield doors between the canister transfer cell and the WP 
positioning cell close on the trolley holding the loaded, unsealed 
WP (Rooms 1011 and 1042). 
CHF-WPC-CC4 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
5. Lid drop onto a WP from the lid placement fixture equipment 
during the welding process (Rooms 2010 and 2032). 
CHF-WPC-CC5A 
CHF-WPC-CC5B 
CHF-WPC -CC5C 
CHF-WPC -CC5D 
CHF-WPC -CC5E 
CHF-WPC -CC5F 
No Drop 
Category 2 
No Drop 
No Breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
6. Equipment drop onto a WP during the welding process (Rooms 
2010 and 2032). 
CHF-WPC-CC6 Beyond Category 2 Same disposition as Potential Event CHF-WPC-CC2. Preventive Procedural 
Safety 
7. Drop or collision of equipment from a canister transfer cell 
overhead crane onto or against a loaded, sealed WP positioned 
on a pedestal on a trolley (Rooms 2010 and 2032). 
CHF-WPC-CC7 Beyond Category 2 Same disposition as Potential Event CHF-WPC-CC2. Preventive Procedural 
Safety 
8. Collision involving the trolley holding the loaded, sealed WP and 
the shield doors between the WP positioning cell and the canister 
transfer cell (Rooms 1011 and 1042). 
CHF-WPC-CC8 Beyond Category 2 (See GET-22) Same disposition as Potential Event CHF-WPC-CC3. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-30 April 2005 
Table III-7. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Closure): Waste Package Positioning Cells (Rooms 1011 and 1042), and Closure Cells (Rooms 2010 and 2032) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Shield doors between the WP positioning cell and the canister 
transfer cell close on the trolley holding the loaded, sealed WP 
(Rooms 1011 and 1042). 
CHF-WPC-CC9 Beyond Category 2 Same disposition as Potential Event CHF-WPC-CC4. Preventive Design 
Chemical 
Contamination-Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1011, 1042, 2010, 
and 2032). 
CHF-WPC-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed canister, therefore this event does not occur unless 
an event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a 
possible outcome of any event that exposes SNF to air. Consequence analyses account 
for the possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. WP inerting system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the WP purging and inerting 
system and the ignition of hydrogen that may have accumulated in 
the WP (Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-EI2 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventative Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with handling equipment and other 
electrically powered equipment in the WP closure cell or the WP 
positioning cell, including the overhead cranes and the welding 
subsystem in the WP closure cells (Rooms 2010 and 2032). 
CHF-WPC-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with a motor on a WP trolley (Rooms 
1011 and 1042). 
CHF-WPC-FT2 Beyond Category 2 Same disposition as Potential Event CHF-WPC-FT1. Preventive Design- 
Procedural 
Safety 
3. Canister/SNF damage by burn-through during welding 
process/heat damage (Rooms 2010 and 2032). 
CHF-WPC-FT3 NA Burn-through of the inner lid is not possible with the gas tungsten arc welding process 
used for the closure welds. 
NA NA 
4. Thermal hazard/canister/SNF overheating in a WP during the 
welding process resulting in excessive cladding temperature and 
possible zircaloy cladding (or other cladding) unzipping 
(Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-FT4 NA Overheating of the waste package contents due to welding is not possible using the gas 
tungsten arc welding process which used for the closure welds. 
NA NA 
5. Overheating of a loaded WP due to a loss of cooling resulting in 
excessive temperature and possible damage to the canister 
contents (Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-FT5 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
6. Transient combustible fire in the WP closure cell or the WP 
positioning cell (Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-FT6 Beyond Category 2 Same disposition as Potential Event CHF-WPC-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-31 April 2005 
Table III-7. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Closure): Waste Package Positioning Cells (Rooms 1011 and 1042), and Closure Cells (Rooms 2010 and 2032) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Glovebox leak leads to a radiological release (Rooms 2007 and 
2029). 
CHF-WPC-R2 Normal Operations Potential exposure of workers to radiation from a glovebox leak is managed as a normaloperations 
dose by routine procedures that ensure that workers do not receive excessive 
radiation doses. 
Mitigative Procedural 
Safety 
3. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-R3 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
4. Inadvertent opening of a canister transfer cell shield door or a WP 
positioning cell shield door, leading to a worker exposure 
(Rooms 1011, 1042, 2010, and 2032). 
CHF-WPC-R4 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1011, 1042, 
2010, and 2032). 
CHF-WPC-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley holding a sealed or unsealed 
WP derailment followed by a load tipover or fall and 
rearrangement of the container internals (Rooms 1011 and 1042). 
CHF-WPC-F1 Beyond Category 2 A design requirement ensures that the trolley can not derail or allow the unsealed waste 
package to fall off the trolley. If the waste package remains upright, there would be no 
event sequence. 
Preventive Design 
2. Criticality associated with a drop of heavy equipment onto an 
unsealed, loaded WP and a rearrangement of the container 
internals (Rooms 2010 and 2032). 
CHF-WPC-F2 Beyond Category 2 A design requirement ensures that an unsealed WP that is dropped onto an essentially 
unyielding surface from within its lift-height limits would not spill its contents. 
Demonstration of compliance must account for the bowing of fuel rods or other 
rearrangement of fissile material that may occur due to a drop or other handling incident. 
An unsealed waste package remains subcritical with credit for moderator control and 
without credit for burnup. Design and operational requirements ensure that moderator 
control is in effect. 
Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HVAC = heating, ventilation, and air-conditioning; NA = not applicable; R = radiation; 
SNF = spent nuclear fuel; WPC = waste package closure. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example CHF, the middle identifies an activity, room, or area, for example WPC, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-32 April 2005 
Table III-8. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Loadout): Canister Transfer Cell. (Room 1033), Waste Package Tool Storage Room. (Room 1032), Exit Vestibule. (Room 1031) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a loaded, sealed WP followed by a 
load tipover or fall (Room 1033). 
CHF-WPL-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Drop of a loaded, sealed WP from a canister transfer cell 
overhead crane onto the floor during transfer from the trolley to 
the survey area (Room 1033). 
CHF-WPL-CC2A 
CHF-WPL-CC2B 
CHF-WPL-CC2C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Design and operational requirements reduce the drop probability. 
Design and operational requirement limits the lift height of waste packages in horizontal 
and vertical orientations. Design requirements ensure that waste packages withstand 
without breaching drops and tipovers within their lift height limits. Design and operational 
requirements limit the probability of exceeding the lift height. 
Preventive Design- 
Procedural 
Safety 
3. Drop or collision of a loaded, sealed WP from a canister transfer 
cell overhead crane onto or against a sharp object during transfer 
from the trolley to the survey area (Room 1033). 
CHF-WPL-CC3 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
4. Slapdown of a loaded, sealed WP that subsequently impacts a 
loaded, unsealed WP on the opposite WP positioning cell trolley 
following a drop from a canister transfer cell overhead crane onto 
the edge of the opposite WP positioning cell trolley, a pit edge, or 
other object during the lift and transfer to the survey area (Room 
1033). 
CHF-WPL-CC4 Beyond Category 2 An operational requirement ensures that whenever a waste-package trolley is being loaded 
onto a trolley or is already on the trolley but not in the waste package positioning cell, the 
opposite trolley remains in its positioning cell or is otherwise out of the way. 
Preventive Design- 
Procedural 
Safety 
5. Slapdown of a loaded, sealed WP that subsequently impacts a 
loaded, sealed WP on the opposite WP positioning cell trolley 
following a drop from a canister transfer cell overhead crane onto 
the edge of the WP positioning cell trolley, a pit edge, or other 
object during the lift and transfer to the survey area (Room 1033). 
CHF-WPL-CC5 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC4. Preventive Design- 
Procedural 
Safety 
6. Drop or collision of a sealed, loaded WP from a canister transfer 
cell overhead crane onto or against a loaded, unsealed WP on the 
opposite WP positioning cell pedestal and trolley during the lift 
and transfer to the survey area. (Room 1033). 
CHF-WPL-CC6 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC4. Additionally, a design requirement 
limits speed for crane transfers such that a collision at the maximum speed could not 
breach an MSC, transportation cask, transfer cask, DPC, DOE or naval canister, or waste 
package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
7. Drop or collision of a sealed, loaded WP from a canister transfer 
cell overhead crane onto or against a loaded, sealed WP on the 
opposite WP positioning cell pedestal and trolley during the lift 
and transfer to the survey area (Room 1033). 
CHF-WPL-CC7 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC6. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-33 April 2005 
Table III-8. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Loadout): Canister Transfer Cell. (Room 1033), Waste Package Tool Storage Room. (Room 1032), Exit Vestibule. (Room 1031) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Drop of a loaded, sealed WP from a canister transfer cell overhead 
crane onto the floor during the transfer from the survey area to the 
tilting machine (Room 1033). 
CHF-WPL-CC8A 
CHF-WPL-CC8B 
CHF-WPL-CC8C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event CHF-WPL-CC2. Preventive Design- 
Procedural 
Safety 
9. Drop of a loaded, sealed WP from a canister transfer cell overhead 
crane back onto the pedestal on the trolley during the transfer from 
the survey area to the tilting machine (Room 1033). 
CHF-WPL-CC9A 
CHF-WPL-CC9B 
CHF-WPL-CC9C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event CHF-WPL-CC2. Preventive Design- 
Procedural 
Safety 
10.Drop or collision of a loaded, sealed WP from a canister transfer 
cell overhead crane onto or against a sharp object (including the 
tilting machine) during transfer from the survey area to the tilting 
machine (Room 1033). 
CHF-WPL-CC10A 
CHF-WPL-CC10B 
CHF-WPL-CC10C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event CHF-WPL-CC2. For collisions, a 
design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
11.Slapdown (either forward into the WP turntable or backward onto 
the floor) of a loaded, sealed WP in the tilting machine from a 
canister transfer cell overhead crane during the lowering of the WP 
to the horizontal position on the pallet previously placed on the WP 
turntable (Room 1033). 
CHF-WPL-CC11 Beyond Category 2 Design requirements ensure that WPs withstand without breaching tipover during 
placement onto the tilting machine, including contact with trunnion cradles or the floor 
(trunnion collars installed). A design requirement prevents backward slapdowns associated 
with the tilting machine for waste packages. 
Preventive Design 
12. Collision of the tilting machine against a loaded, sealed WP on a 
pallet on the WP turntable (Room 1033). 
CHF-WPL-CC12 Beyond Category 2 A design or operational requirement ensures that an impact or collision between the 
trunnion collar removal machine, WP turntable, or WP tilting machine and a WP will not 
breach the WP or cause it to fall off the emplacement pallet. 
Preventive Design- 
Procedural 
Safety 
13.Drop or collision of a lifting collar from a canister transfer cell 
overhead crane onto or against a WP after removal of the collar 
from the WP collar removal machine (Room 1033). 
CHF-WPL-CC13 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
14. Collision or impact of the trunnion collar removal machine and a 
loaded, sealed WP positioned on a pallet positioned on the WP 
turntable (Room 1033). 
CHF-WPL-CC14 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC12. Preventive Design- 
Procedural 
Safety 
15. Drop of a loaded, sealed WP positioned on a pallet (from a 
horizontal position) from a canister transfer cell overhead crane 
onto the floor or the bedplate during transfer of the WP and pallet 
from the WP turntable to the WP transporter bedplate 
(Room 1033). 
CHF-WPL-CC15A 
CHF-WPL-CC15B 
CHF-WPL-CC15C 
No drop 
No breach 
Beyond Category 2 
See GET-08) Same disposition as Potential Event CHF-WPL-CC2. Preventive Design- 
Procedural 
Safety 
16.Drop or collision of a loaded, sealed WP positioned on a pallet 
(from a horizontal position) from a canister transfer cell overhead 
crane onto or against a sharp object during transfer of the WP and 
pallet from the WP turntable to the WP transporter bedplate (Room 
1033). 
CHF-WPL-CC16 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC3. Preventive Design- 
Procedural 
Safety 
17.Equipment drop or collision (including lifting yokes) onto or against 
a loaded, sealed WP when the WP is on the pallet on the WP 
turntable or when the WP is on the pallet on the WP transporter 
bedplate (Room 1033). 
CHF-WPL-CC17 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC13. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-34 April 2005 
Table III-8. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Loadout): Canister Transfer Cell. (Room 1033), Waste Package Tool Storage Room. (Room 1032), Exit Vestibule. (Room 1031) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
18. Collision involving a WP transporter (holding the sealed WP on a 
pallet) and the shield doors between the canister transfer cell and 
the WP tool storage room (Room 1033). 
CHF-WPL-CC18 Beyond Category 2 A design requirement ensures that the WP transporter transports the WP in a manner such 
that if a collision or derailment (excluding tipover) occurs, the WP impact energy would be 
low enough to preclude a WP breach. A design requirement ensures that the WP 
transporter transports the WP in a manner such that if a collision or derailment leading to a 
transporter tipover occurs, the WP impact energy would be low enough to preclude a WP 
breach. 
Preventive Design 
19.The shield doors between the canister transfer cell and the WP tool 
storage room close on the WP transporter (holding the sealed WP 
on a pallet) (Room 1032). 
CHF-WPL-CC19 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
20. Collision involving WP transporter (holding the sealed WP on a 
pallet) and the doors between the WP tool storage room and the 
exit vestibule (Room 1032). 
CHF-WPL-CC20 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC18. Preventive Design 
21.The doors between the WP tool storage room and the exit vestibule 
close on the WP transporter (holding the sealed WP on a pallet) 
(Room 1031). 
CHF-WPL-CC21 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC19. Preventive Design 
22. Collision involving WP transporter (holding the sealed WP on a 
pallet) and the doors between the exit vestibule and the ambient air 
(outside) (Room 1031). 
CHF-WPL-CC22 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC18. Preventive Design 
23.Doors between the exit vestibule and the ambient air (outside) 
close on the WP transporter (holding the sealed WP on a pallet) 
(Room 1031). 
CHF-WPL-CC23 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC19. Preventive Design 
24.Derailment of a WP transporter in the exit vestibule, WP tool 
storage room, or WP loadout area of the canister transfer cell 
followed by a load tipover or fall (Room 1031). 
CHF-WPL-CC24 Beyond Category 2 Same disposition as Potential Event CHF-WPL-CC18. Preventive Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures. (Rooms 1031, 1032, and 1033). 
CHF-WPL-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained in a sealed canister, therefore this event does not occur unless an 
event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible 
outcome of any event that exposes SNF to air. Consequence analyses account for the 
possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Hydraulic system or other pneumatic or pressurized system missile 
due to a fractured nozzle/valve stem/pneumatic device (Rooms 
1031, 1032, and 1033). 
CHF-WPL-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the WP transporter loadout area 
housing the equipment for WP tilt and WP transporter loading, as 
well as the WP tool storage room and the exit vestibule (including 
the WP trunnion collar removal machine, the tilting machine, and 
the WP turntable) (Rooms 1031, 1032, and 1033). 
CHF-WPL-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with the overhead bridge cranes (Rooms 
1031, 1032, and 1033). 
CHF-WPL-FT2 Beyond Category 2 Same disposition as Potential Event CHF-WPL-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-35 April 2005 
Table III-8. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Loadout): Canister Transfer Cell. (Room 1033), Waste Package Tool Storage Room. (Room 1032), Exit Vestibule. (Room 1031) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Electrical fire associated with equipment on the WP transporter, 
including motors to extend the WP transporter bedplate 
(Rooms 1031, 1032, and 1033). 
CHF-WPL-FT3 Beyond Category 2 Same disposition as Potential Event CHF-WPL-FT1. Preventive Design- 
Procedural 
Safety 
4. Electrical fire associated with the WP transport locomotive (Rooms 
1031, 1032, and 1033). 
CHF-WPL-FT4 Beyond Category 2 Same disposition as Potential Event CHF-WPL-FT1. Preventive Design- 
Procedural 
Safety 
5. Electrical fire associated with a motor on a WP trolley 
(Rooms 1031, 1032, and 1033). 
CHF-WPL-FT5 Beyond Category 2 Same disposition as Potential Event CHF-WPL-FT1. Preventive Design- 
Procedural 
Safety 
6. Overheating of a loaded, sealed WP due to a loss of cooling 
resulting in excessive temperature and possible damage to the 
canister contents (Rooms 1031, 1032, and 1033). 
CHF-WPL-FT6 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
7. Transient combustible fire in the canister transfer area, the WP tool 
storage room, or the exit vestibule (Rooms 1031, 1032, and 1033). 
CHF-WPL-FT7 Beyond Category 2 Same disposition as Potential Event CHF-WPL-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1031, 1032, and 1033). 
CHF-WPL-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1031, 1032, and 1033). 
CHF-WPL-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Inadvertent opening of a canister transfer cell shield door, leading 
to a worker exposure (Rooms 1031, 1032, and 1033). 
CHF-WPL-R3 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
4. Inadvertent opening of the WP transporter shielded enclosure 
doors, leading to a worker exposure (Rooms 1031, 1032, and 
1033). 
CHF-WPL-R4 Beyond Category 2 Same disposition as Potential Event CHF-WPL-R3. Preventive Design- 
Procedural 
Safety 
Fissile 1. Criticality associated with a trolley holding a WP derailment 
followed by a load tipover or fall and rearrangement of the WP 
internals (Room 1033). 
CHF-WPL-F1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Criticality associated with a WP transporter derailment followed by 
a load tipover or fall and rearrangement of the WP internals 
(Rooms 1031, 1032, and 1033). 
CHF-WPL-F2 Beyond Category 2 Same disposition as Potential Events CHF-WPL-CC18 and CHF-WPL-F3. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-36 April 2005 
Table III-8. Disposition of Internal Events That Occur Inside the Canister Handling Facility (Waste Package Loadout): Canister Transfer Cell. (Room 1033), Waste Package Tool Storage Room. (Room 1032), Exit Vestibule. (Room 1031) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Criticality associated with a drop, slapdown, or collision of a WP 
and a rearrangement of the container internals (Rooms 1031, 
1032, and 1033). 
CHF-WPL-F3 Beyond Category 2 A design requirement ensures that sealed waste packages are designed such that drops, 
collisions, and other handling impacts within their design bases, allowing for rearrangement 
of the waste package internals and without credit for burnup, cannot lead to a nuclear 
criticality. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; NA = not applicable; R = radiation; SNF = spent nuclear fuel; WPL = waste package 
loadout. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example CHF, the middle identifies an activity, room, or area, for example WPL, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-37 April 2005 
Table III-9. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Entrance Vestibule (Room 1079), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), Cask and Site-specific Cask to 
Trolley Transfer Room (Room 1076) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. SRTC derailment involving a loaded cask (with impact limiters 
installed) followed by a load tipover or fall (Room 1079). 
DTF-CMSCEV-CC1 Beyond Category 2 Transportation casks with impact limiters are designed to withstand, without breaching, the 
bounding drops that could occur during cask handling at the repository. Consequently, a 
derailment, overturning or collision would not breach a transportation cask. 
Preventive Design 
2. Collision of an SRTC carrying a loaded cask (with impact limiters 
installed) with the cask and MSC entrance vestibule doors or the 
cask and MSC SRTC receipt area doors (Rooms 1077 and 1079). 
DTF-CMSCEV-CC2 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC1. Preventive Design 
3. The cask and MSC entrance vestibule doors or the cask and MSC 
SRTC receipt area doors close on an SRTC carrying a loaded 
cask (with impact limiters installed) (Rooms 1077 and 1079). 
DTF-CMSCEV-CC3 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
4. MSC transporter collision or overturning involving a loaded MSC 
followed by a load tipover or fall (Rooms 1077 and 1079). 
DTF-CMSCEV-CC4 Beyond Category 2 Design and operational requirements establish speed limits such that a collision with shield 
or airlock doors or other heavy objects would not overturn an SRTC, or site-specific cask 
transporter or cause it to lose its load. 
Preventive Design- 
Procedural 
Safety 
5. Collision of an MSC transporter carrying a loaded MSC with the 
cask and MSC entrance vestibule doors or the cask and MSC 
SRTC receipt area shield doors (Rooms 1077 and 1079). 
DTF-CMSCEV-CC5 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC4. Preventive Design- 
Procedural 
Safety 
6. The cask and MSC entrance vestibule doors or the cask and MSC 
SRTC receipt area shield doors close on an MSC transporter 
carrying a loaded MSC (Rooms 1077 and 1079). 
DTF-CMSCEV-CC6 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC3. Preventive Design 
7. Collision of a mobile elevated platform with a loaded cask during 
removal of the personnel barriers and impact limiters or during 
survey activities (Room 1077). 
DTF-CMSCEV-CC7 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, mobile 
elevated platforms, and forklifts operated in the facility are not operated in a manner that 
could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
8. Forklift collision with a cask on an SRTC (with or without impact 
limiters installed on the cask) or the SRTC holding the cask 
(Room 1077). 
DTF-CMSCEV-CC8 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC7. Preventive Procedural 
Safety 
9. Collision between a forklift and an MSC positioned on the floor, an 
MSC on a pedestal on a trolley, or the MSC transporter holding 
the MSC (Room 1077). 
DTF-CMSCEV-CC9 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC7. Preventive Procedural 
Safety 
10. Collision between a mobile elevated platform and an MSC 
positioned on the floor, an MSC on a pedestal on a trolley, or the 
MSC transporter holding the MSC (Room 1077). 
DTF-CMSCEV-CC10 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC7. Preventive Procedural 
Safety 
11.Drop or collision of personnel barriers or impact limiters from the 
receipt area crane onto or against a loaded cask (Room 1077). 
DTF-CMSCEV-CC11 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-38 April 2005 
Table III-9. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Entrance Vestibule (Room 1079), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), Cask and Site-specific Cask to Trolley 
Transfer Room (Room 1076) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
12.Slapdown of a loaded cask onto an SRTC during the upending of 
the loaded cask to the vertical orientation by the overhead crane 
(Room 1076). 
DTF-CMSCEV-CC12A 
DTF-CMSCEV-CC12B 
DTF-CMSCEV-CC12C 
DTF-CMSCEV-CC12D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact limiters 
and site-specific casks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. 
Preventive Design- 
Procedural 
Safety 
13. Drop of a loaded cask from an overhead crane onto the floor 
during the transfer from an SRTC to a pedestal previously staged 
on a trolley (Room 1076). 
DTF-CMSCEV-CC13A 
DTF-CMSCEV-CC13B 
DTF-CMSCEV-CC13C 
DTF-CMSCEV-CC13D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event DTF-CMSCEV-CC12. Preventive Design- 
Procedural 
Safety 
14. Drop of a loaded cask from an overhead crane onto the pedestal 
on a trolley during the transfer from an SRTC to a pedestal 
previously staged on a trolley (Room 1076). 
DTF-CMSCEV-CC14A 
DTF-CMSCEV-CC14B 
DTF-CMSCEV-CC14C 
DTF-CMSCEV-CC14D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event DTF-CMSCEV-CC12. Preventive Design- 
Procedural 
Safety 
15.Drop or collision of a loaded cask from an overhead crane onto or 
against a sharp object during the transfer from an SRTC to a 
pedestal previously positioned on the trolley (Room 1076). 
DTF-CMSCEV-CC15 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
16.Slapdown of a loaded cask following a drop from an overhead 
crane onto the edge of the trolley or pedestal during transfer of the 
cask from the SRTC to the pedestal on a trolley (Room 1076). 
DTF-CMSCEV-CC16A 
DTF-CMSCEV-CC16B 
DTF-CMSCEV-CC16C 
DTF-CMSCEV-CC16D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event DTF-CMSCEV-CC12. Preventive Design- 
Procedural 
Safety 
17. Collision of a loaded cask suspended from an overhead crane with 
the shield doors separating the cask and MSC SRTC receipt area 
and the cask and MSC to trolley transfer room during the transfer 
of the cask from the SRTC to the trolley (Rooms 1076 and 1077). 
DTF-CMSCEV-CC17 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
18.Closing of the shield doors separating the cask and MSC SRTC 
receipt area and the cask and MSC to trolley transfer room (striking 
a loaded cask while it is suspended from the overhead crane) 
during the transfer of the cask from the SRTC to the pedestal on a 
trolley (Room 1076). 
DTF-CMSCEV-CC18 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC3. Preventive Design 
19. Drop of a loaded MSC from an overhead crane onto the floor 
during the transfer from an SRTC to a pedestal previously 
positioned on a trolley (Room 1076). 
DTF-CMSCEV-CC19A 
DTF-CMSCEV-CC19B 
DTF-CMSCEV-CC19C 
DTF-CMSCEV-CC19D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event DTF-CMSCEV-CC12 Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-39 April 2005 
Table III-9. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Entrance Vestibule (Room 1079), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), Cask and Site-specific Cask to Trolley 
Transfer Room (Room 1076) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
20. Drop of a loaded MSC from an overhead crane onto the pedestal 
on a trolley during the transfer from an SRTC to a pedestal 
previously positioned on a trolley (Room 1076). 
DTF-CMSCEV-CC20A 
DTF-CMSCEV-CC20B 
DTF-CMSCEV-CC20C 
DTF-CMSCEV-CC20D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event DTF-CMSCEV-CC12. Preventive Design- 
Procedural 
Safety 
21.Drop or collision of a loaded MSC from an overhead crane onto or 
against a sharp object during the transfer from the floor (after 
delivery by the MSC transporter) to a pedestal previously staged 
on trolley (Room 1076). 
DTF-CMSCEV-CC21 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC15. Preventive Design- 
Procedural 
Safety 
22.Collision of a loaded MSC suspended from an overhead crane with 
the shield doors separating the cask and MSC SRTC receipt area 
and the cask and MSC to trolley transfer room during transfer of 
the MSC from the floor (after delivery by the MSC transporter) to 
the pedestal on a trolley (Room 1076). 
DTF-CMSCEV-CC22 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC17. Preventive Design 
23.Closing of the shield doors separating the cask and MSC SRTC 
receipt area and the cask and MSC to trolley transfer room (striking 
a loaded MSC while it is suspended from the overhead crane) 
during the transfer of the MSC from the floor (after delivery by the 
MSC transporter) to the pedestal on a trolley. (Room 1076). 
DTF-CMSCEV-CC23 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC3. Preventive Design 
24.Slapdown of a loaded MSC following a drop from an overhead 
crane onto the edge of the trolley or pedestal during transfer of the 
MSC from the floor (after delivery by the MSC transporter) to the 
pedestal on a trolley (Room 1076). 
DTF-CMSCEV-CC24A 
DTF-CMSCEV-CC24B 
DTF-CMSCEV-CC24C 
DTF-CMSCEV-CC24D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event DTF-CMSCEV-CC12. Preventive Design- 
Procedural 
Safety 
25.Drop or collision of handling equipment from an overhead bridge 
crane onto or against a loaded cask or MSC (Room 1076). 
DTF-CMSCEV-CC25 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC11. Preventive Procedural 
Safety 
26.Drop or collision of equipment from the maintenance crane onto or 
against a loaded cask or MSC (Room 1076). 
DTF-CMSCEV-CC26 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC11. Preventive Procedural 
Safety 
27.Collision of a trolley holding a cask or MSC on a pedestal with the 
shield doors separating the cask and MSC to trolley transfer room 
and the cask and MSC turntable room (Room 1076). 
DTF-CMSCEV-CC27 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
28.The shield doors separating the cask and MSC to trolley transfer 
room and the cask and MSC turntable room close on a trolley 
holding a loaded cask or MSC on a pedestal (Room 1076). 
DTF-CMSCEV-CC28 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-CC3. Preventive Design 
29.Derailment of a trolley holding a cask or MSC on a pedestal 
followed by a load tipover or fall (Room 1076). 
DTF-CMSCEV-CC29 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed cask, therefore this event does not occur unless an 
event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible 
outcome of any event that exposes SNF to air. Consequence analyses account for the 
possibility of oxidation, as applicable. 
NA NA
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-40 April 2005 
Table III-9. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Entrance Vestibule (Room 1079), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), Cask and Site-specific Cask to Trolley 
Transfer Room (Room 1076) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a cask trolley 
(Room 1076). 
DTF-CMSCEV-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a forklift(Room 1077). DTF-CMSCEV-EI2 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-EI1. Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1077). 
DTF-CMSCEV-EI3 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the cask and MSC SRTC receipt 
area overhead cranes (Rooms 1076 and 1077). 
DTF-CMSCEV-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or Category 
2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
electrical equipment in the cask and MSC entrance vestibule, cask 
and MSC SRTC receipt area, or the cask and MSC to trolley 
transfer room (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-FT2 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
3. Diesel fuel fire/explosion involving an SRTC tractor pulling or 
pushing an SRTC holding a loaded cask (Rooms 1077 and 1079). 
DTF-CMSCEV-FT3 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
4. Diesel fuel fire/explosion involving an MSC transporter holding a 
loaded MSC (Rooms 1077 and 1079). 
DTF-CMSCEV-FT4 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with the cask 
trolley (Room 1076). 
DTF-CMSCEV-FT5 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with a forklift 
(Room 1077). 
DTF-CMSCEV-FT6 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
7. Fire/explosion (battery/electrical fire) associated with a mobile 
elevated platform (Room 1077). 
DTF-CMSCEV-FT7 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
8. Transient combustible fire in the cask and MSC SRTC receipt 
area, the cask and MSC entrance vestibule, or the cask and MSC 
to trolley transfer room (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-FT8 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-FT1. Preventive Design- 
Procedural 
Safety 
9. Thermal hazard (from decay heat) associated with a vertical 
orientation of a loaded cask (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-FT9 Beyond Category 2 Transportation casks are designed to withstand normal conditions of transport (including 
high ambient temperatures and insolation) and hypothetical accident conditions (including 
fire). These conditions bound the thermal effect of orienting the cask vertically rather than 
horizontally. This potential event would not cause oxidation of SNF leading to exposure of 
individuals to radiation because the waste is contained in a sealed cask. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-41 April 2005 
Table III-9. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Entrance Vestibule (Room 1079), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), Cask and Site-specific Cask to Trolley 
Transfer Room (Room 1076) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal operations 
does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Radiation-induced damage to a facility SSC (Rooms 1076, 1077, 
and 1079). 
DTF-CMSCEV-R3 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with an SRTC derailment or collision followed 
by a load tipover or fall and a rearrangement of cask internals 
(Rooms 1077 and 1079). 
DTF-CMSCEV-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a cask drop, slapdown, or collision and 
rearrangement of cask internals (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-F2 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-F1. Preventive Design 
3. Criticality associated with an MSC drop, slapdown, or collision and 
rearrangement of cask internals (Rooms 1076, 1077, and 1079). 
DTF-CMSCEV-F3 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-F1. Preventive Design 
4. Criticality associated with an MSC transporter (holding a loaded 
MSC) collision followed by a load tipover or fall and rearrangement 
of the MSC internals (Rooms 1077 and 1079). 
DTF-CMSCEV-F4 Beyond Category 2 Same disposition as Potential Event DTF-CMSCEV-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; CMSCEV = cask and site-specific cask entrance vestibule; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = highlevel 
radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example CMSCEV, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-42 April 2005 
Table III-10. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask/Site-specific Cask Turntable Room (Room 1073), Cask Preparation Room (Room 1074), Cask Docking Ring Installation Room (Room 2051) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a cask or MSC on a pedestal (with 
outer and/or inner lid bolted in place, if applicable) followed by a 
load tipover or fall (Rooms 1073 and 1074). 
DTF-CTRPR-CC1 Beyond Category 2 A design requirement ensures that loaded-transfer trolleys do not derail or drop their loads 
during normal operation or as a result of a turntable malfunction. Design requirements 
apply to trolleys for transportation casks, site-specific casks, and dual-purpose canisters. 
Preventive Design 
2. Derailment of a trolley holding a cask or MSC on a pedestal (with 
outer and/or inner lid bolted in place, if applicable) due to a 
turntable malfunction followed by a load tipover or fall (Rooms 
1073 and 1074). 
DTF-CTRPR-CC2 Beyond Category 2 Same disposition as Potential Event DTF-CTRPR-CC1. Preventive Design 
3. Collision of a trolley holding a cask or MSC on a pedestal (with 
outer and/or inner lid bolted in place, if applicable) with shield 
doors separating the cask/MSC turntable room and the cask 
preparation room (Rooms 1073 and 1074). 
DTF-CTRPR-CC3 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
4. Closure of the shield doors separating the cask/MSC turntable 
room and the cask preparation room onto the trolley holding a 
cask or MSC on a pedestal (with outer and/or inner lid bolted in 
place, if applicable) (Rooms 1073 and 1074). 
DTF-CTRPR-CC4 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
5. Collision involving two trolleys with at least one holding a cask or 
MSC on a pedestal (with outer and/or inner lid bolted in place, if 
applicable) (Rooms 1073 and 1074). 
DTF-CTRPR-CC5 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-CTRPR-CC3. Preventive Design 
6. Drop or collision of tools or equipment (including a lid-lifting 
fixture, lid bolts, etc.) onto or against a cask or MSC outer lid (if 
applicable) or a cask or MSC inner lid in the cask preparation 
room (Room 1074). 
DTF-CTRPR-CC6 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, do not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
7. Drop of a cask or MSC outer lid from the overhead crane onto the 
cask or MSC (if applicable) in the cask preparation room (Room 
1074). 
DTF-CTRPR-CC7A 
DTF-CTRPR-CC7B 
DTF-CTRPR-CC7C 
DTF-CTRPR-CC7D 
DTF-CTRPR-CC7E 
DTF-CTRPR-CC7F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design - 
Procedural 
Safety 
8. Drop or collision of a docking ring onto or against a cask or MSC 
in the cask preparation room (Room 1074). 
DTF-CTRPR-CC8 Beyond Category 2 Same DTF-CTRPR-CC6. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-43 April 2005 
Table III-10. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask/Site-specific Cask Turntable Room (Room 1073), Cask Preparation Room (Room 1074), Cask Docking Ring Installation Room (Room 2051) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1073 and 1074). 
DTF-CTRPR-CCF1 Normal Operations Oxidation of failed commercial SNF, not contained inside a sealed canister, is expected as 
a part of normal operations whenever commercial SNF is exposed to air. Any resulting 
potential exposure of workers to radiation is managed as a normal-operations dose by 
procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Cask purging or sampling system (or other pneumatic or 
pressurized system) missile due to a fractured nozzle/valve 
stem/pneumatic device (Rooms 1073 and 1074). 
DTF-CTRPR-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask, with or without impact limiters, a 
transfer cask, a DOE SNF canister, a naval SNF canister, a dual-purpose canister, the 
inner lid of a transportation cask, a site-specific cask, a waste package, or the inner lid of a 
site-specific cask or waste package, are not present in areas where vulnerable items may 
be exposed. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the cask sampling and purging 
system and the ignition of hydrogen that may have accumulated in 
the cask (Rooms 1073 and 1074). 
DTF-CTRPR-EI2 Beyond Category 2 Precautions taken during the cask sampling and purging process provide reasonable 
assurance that such hydrogen explosions would not occur. 
Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a trolley (Rooms 1073 
and 1074). 
DTF-CTRPR-EI3 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the cask preparation area 20-ton 
overhead crane (Room 2051). 
DTF-CTRPR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other cask 
preparation area equipment, including the turntable (Rooms 1073 
and 1074). 
DTF-CTRPR-FT2 Beyond Category 2 Same disposition as Potential Event DTF-CTRPR-FT1. Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) associated with the trolley 
(Rooms 1073 and 1074). 
DTF-CTRPR-FT3 Beyond Category 2 Same disposition as Potential Event DTF-CTRPR-FT1. Preventive Design- 
Procedural 
Safety 
4. Transient combustible fire in the cask preparation room or the 
cask/MSC turntable room (Rooms 1073 and 1074). 
DTF-CTRPR-FT4 Beyond Category 2 Same disposition as Potential Event DTF-CTRPR-FT1. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
5. Thermal hazard (from decay heat) associated with vertical 
orientation of the loaded cask (Rooms 1073 and 1074). 
DTF-CTRPR-FT5 Normal Operations Same disposition as Potential Event DTF-CTRPR-CCF1. Mitigative Procedural 
Safety 
6. Intact or non-intact SNF overheating or damage to cask or MSC 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
(Rooms 1073 and 1074). 
DTF-CTRPR-FT6 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1073 and 1074). 
DTF-CTRPR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-44 April 2005 
Table III-10. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask/Site-specific Cask Turntable Room (Room 1073), Cask Preparation Room (Room 1074), Cask Docking Ring Installation Room (Room 2051) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Damage or rupture of cask sampling and purging system, leading 
to a release of cask or MSC internal gases and radioactive 
material (Rooms 1073 and 1074). 
DTF-CTRPR-R2 Normal Operations The sampling operation is conducted so that exposure of workers to radiation is managed 
as a normal-operations dose by procedures for monitoring radiation doses and assigning 
work, which ensure that workers do not receive excessive radiation doses. Although a 
rupture leading to a radiological release would be an off-normal occurrence, any release 
and related dose would be managed as part of routine radiation protection operations. 
Mitigative Procedural 
Safety 
3. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Rooms 
1073 and 1074). 
DTF-CTRPR-R3 Normal Operations An exposure of workers to radiation due to this potential event is managed as a normaloperations 
dose by procedures that ensure workers do not receive excessive radiation 
doses. 
Mitigative Procedural 
Safety 
4. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1073 and 1074). 
DTF-CTRPR-R4 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1073 and 
1074). 
DTF-CTRPR-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a cask or MSC collision followed by a 
load tipover or fall and a rearrangement of the cask or MSC 
internals (Rooms 1073 and 1074). 
DTF-CTRPR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a cask or MSC trolley derailment 
followed by a load tipover or fall and a rearrangement of the cask 
or MSC internals (Rooms 1073 and 1074). 
DTF-CTRPR-F2 Beyond Category 2 Same disposition as Potential Event DTF-CTRPR-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; CTRPR = cask turntable room preparation room; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level 
radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example CTRPR, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-45 April 2005 
Table III-11. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Docking Room. (Room 1069) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a cask or MSC on a pedestal (with 
outer lid removed [if applicable] and inner lid unbolted but in 
place) followed by a load tipover or fall. (Room 1069). 
DTF-CSKDR-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Derailment of a trolley holding a cask or MSC on a pedestal (with 
outer lid removed [if applicable] and inner lid unbolted but in 
place) due to a turntable malfunction followed by a load tipover or 
fall (Room 1069). 
DTF-CSKDR-CC2 Beyond Category 2 Same disposition as Potential Event DTF-CSKDR-CC1. Preventive Design 
3. Collision of a trolley holding a cask or MSC on a pedestal (with 
outer lid removed [if applicable] and inner lid unbolted but in 
place) with shield doors separating the cask preparation room and 
the cask/MSC turntable room or the shield doors separating the 
cask/MSC turntable room and the cask and MSC docking room 
(Room 1069). 
DTF-CSKDR-CC3 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
4. Closure of the shield doors separating the cask preparation room 
and the cask/MSC turntable room or the shield doors separating 
the cask/MSC turntable room and the cask and MSC docking 
room onto the trolley holding a cask or MSC on a pedestal (with 
outer lid removed [if applicable] and inner lid unbolted but in 
place) (Room 1069). 
DTF-CSKDR-CC4 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
5. Collision involving two trolleys with at least one holding a cask or 
MSC on a pedestal (with outer lid removed [if applicable] and 
inner lid unbolted but in place) (Room 1069). 
DTF-CSKDR-CC5 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-CSKDR-CC3. Preventive Design 
6. Drop or collision of a docking port (mobile slab) onto or against a 
cask or MSC (Room 1069). 
DTF-CSKDR-CC6 Beyond Category 2 A design requirement ensures that a drop of or collision involving components associated 
with a docking port will not breach the lid of a cask or MSC situated at the docking port. 
Preventive Design 
7. Drop or collision of a docking port plug onto or against a cask lid 
or MSC lid (with outer lid removed [if applicable] and inner lid 
unbolted but in place) (Room 1069). 
DTF-CSKDR-CC7 Beyond Category 2 Design requirements ensure that portions of a non-ITS SSC which, upon failure, could 
adversely interact with an ITS SSC and prevent its safety function from being performed 
are classified as ITS, redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC, or, for seismic interactions, designed to the same seismic DBGM as 
the ITS SSCs subjected to the potential unacceptable interaction. 
Preventive Design 
8. Drop of an inner lid into a cask or MSC (with outer lid removed [if 
applicable]) (Room 1069). 
DTF-CSKDR-CC8A 
DTF-CSKDR-CC8B 
DTF-CSKDR-CC8C 
DTF-CSKDR-CC8D 
DTF-CSKDR-CC8E 
DTF-CSKDR-CC8F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-46 April 2005 
Table III-11. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Docking Room. (Room 1069) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1069). 
DTF-CSKDR-CCF1 Normal Operations Oxidation of failed commercial SNF, not contained inside a sealed canister, is expected as 
a part of normal operations whenever commercial SNF is exposed to air. Any resulting 
potential exposure of workers to radiation is managed as a normal-operations dose by 
procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a cask trolley 
(Room 1069). 
DTF-CSKDR-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with handling equipment or other cask 
and MSC docking room equipment (including the turntable). 
(Room 1069). 
DTF-CSKDR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) associated with the cask 
trolley (Room 1069). 
DTF-CSKDR-FT2 Beyond Category 2 Same disposition as Potential Event DTF-CSKDR-FT1. Preventive Design- 
Procedural 
Safety 
3. Transient combustible fire in the cask and MSC docking room 
(Room 1069). 
DTF-CSKDR-FT3 Beyond Category 2 Same disposition as Potential Event DTF-CSKDR-FT1. Preventive Design- 
Procedural 
Safety 
4. Thermal hazard (from decay heat) associated with vertical 
orientation of the loaded cask (Room 1069). 
DTF-CSKDR-FT4 Normal Operations Same disposition as Potential Event DTF-CSKDR-CCF1. Mitigative Procedural 
Safety 
5. Intact or non-intact SNF overheating or damage to cask contents 
due to a loss of cooling resulting in excessive temperature and 
possible zircaloy cladding (or other cladding) unzipping or 
cladding failure due to excessive hoop stresses (Room 1069). 
DTF-CSKDR-FT5 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1069). 
DTF-CSKDR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Docking ring failure leads to a radiological release (Room 1069). DTF-CSKDR-R2 NA (no significant 
exposure) 
Same disposition as Potential Event DTF-CSKDR-R5. Mitigative Procedural 
Safety 
3. Radiological release due to installation of incorrect docking ring 
(Room 1069). 
DTF-CSKDR-R3 NA (no significant 
exposure) 
Same disposition as Potential Event DTF-CSKDR-R5. Mitigative Procedural 
Safety 
4. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Room 
1069). 
DTF-CSKDR-R4 Normal Operations Thermal expansion of gases is expected as a part of normal operations. Any resulting 
potential exposure of workers to radiation is managed as a normal operations dose by 
procedures that ensure workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
5. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1069). 
DTF-CSKDR-R5 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
6. Radiation-induced damage to a facility SSC (Room 1069). DTF-CSKDR-R6 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-47 April 2005 
Table III-11. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and Site-specific Cask Docking Room. (Room 1069) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Fissile 1. Criticality associated with cask or MSC collisions or a trolley 
derailment followed by a load tipover or fall and a rearrangement 
of cask or MSC internals (Room 1069). 
DTF-CSKDR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; CSKDR = cask docking room; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; NA = not 
applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example CDSKDR, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-48 April 2005 
Table III-12. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval Spent Nuclear Fuel Receipt): Waste Package and Navy Cask Entrance Vestibule. (Room 1060), Waste Package/Navy Cask SRTC Receipt Area. 
(Room 1058), Waste Package/Navy to Trolley Transfer Room (Room 1057), Waste Package/Navy Cask Preparation Room (Room 1053). 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. SRTC derailment involving a loaded naval SNF cask followed by a 
load tipover or fall (Rooms 1058 and 1060). 
DTF-NSNFR-CC1 Beyond Category 2 Transportation casks with impact limiters are designed to withstand, without breaching, the 
bounding drops that could occur during cask handling at the repository. A derailment, 
overturning, or collision does not breach a transportation cask with impact limiters. A 
design requirement ensures that an SRTC carrying a cask without impact limiters (typically 
only within structures) or site-specific cask does not derail and the cask or site-specific cask 
does not fall from the SRTC under normal operating conditions or as the result of a 
collision. 
Preventive Design 
2. Collision of an SRTC carrying a loaded naval SNF cask with the 
WP and navy cask entrance vestibule doors or the WP/navy cask 
SRTC receipt area shield doors (Rooms 1058 and 1060). 
DTF-NSNFR-CC2 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC1. Preventive Design 
3. The WP and navy cask entrance vestibule doors or the WP/navy 
cask SRTC receipt area shield doors close on an SRTC carrying a 
loaded cask (Rooms 1058 and 1060). 
DTF-NSNFR-CC3 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
4. Collision of mobile elevated platforms with a loaded naval SNF 
cask during removal of personnel barriers and impact limiters or 
during survey activities (Room 1058). 
DTF-NSNFR-CC4 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
5. Forklift collision with a naval SNF cask on an SRTC (with or 
without impact limiters installed on the cask) or the SRTC holding 
the cask (Room 1058). 
DTF-NSNFR-CC5 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC4. Preventive Procedural 
Safety 
6. Drop or collision of personnel barriers or impact limiters from the 
receipt area crane onto or against a loaded naval SNF cask 
(Room 1058). 
DTF-NSNFR-CC6 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety 
7. Slapdown of a loaded naval SNF cask onto an SRTC during 
upending of the loaded cask to the vertical orientation 
(Room 1058). 
DTF-NSNFR-CC7A Category 2 (See GET-01 Sequence A) Design and operational requirements reduce the drop 
probability. 
Preventive Design- 
Procedural 
Safety 
8. Drop of a loaded naval SNF cask from the overhead crane onto 
the floor during the transfer from an SRTC to a pedestal 
previously positioned on a trolley (Room 1058). 
DTF-NSNFR-CC8A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event DTF-NSNFR-CC7. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-49 April 2005 
Table III-12. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval SNF Receipt): Waste Package and Navy Cask Entrance Vestibule. (Room 1060), Waste Package/Navy Cask SRTC Receipt Area. (Room 1058), Waste 
Package/Navy to Trolley Transfer Room. (Room 1057), Waste Package/Navy Cask Preparation Room (Room 1053) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Drop of a loaded naval SNF cask from the overhead crane onto a 
pedestal on a trolley during the transfer from an SRTC to a 
pedestal previously positioned on a trolley (Room 1058). 
DTF-NSNFR-CC9A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event DTF-NSNFR-CC7. Preventive Design- 
Procedural 
Safety 
10.Drop or collision of a loaded cask from the overhead crane onto or 
against a sharp object during the transfer from an SRTC to a 
pedestal previously positioned on trolley (Room 1058). 
DTF-NSNFR-CC10 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
11. Collision of a loaded naval SNF cask suspended from the 
overhead crane with the shield doors separating the WP/navy 
cask SRTC receipt area and the WP/navy to trolley transfer room 
during transfer of the naval SNF cask from the SRTC to the trolley 
(Room 1058). 
DTF-NSNFR-CC11 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
12.Closing of the shield doors separating the WP/navy cask SRTC 
receipt area and the WP/navy to trolley transfer room (striking the 
cask while the loaded cask is suspended from the overhead 
crane) during the transfer of the cask from the SRTC to the trolley 
(Rooms 1057 and 1058). 
DTF-NSNFR-CC12 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC3. Preventive Design 
13.Slapdown of a loaded naval SNF cask following a drop from the 
overhead crane onto the edge of the trolley or pedestal during 
transfer of the cask from the SRTC to the trolley (Room 1057). 
DTF-NSNFR-CC13A Category 2 (See GET-01 Sequence A) Same disposition as Potential Event DTF-NSNFR-CC7. Preventive Design- 
Procedural 
Safety 
14.Drop or collision of handling equipment from the overhead bridge 
crane onto or against a loaded naval SNF cask (Rooms 1057 
and 1058). 
DTF-NSNFR-CC14 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC6 Preventive Procedural 
Safety 
15.Drop or collision of other miscellaneous (non-handling) equipment 
(gas-sampling, lid-bolt removal, etc.) from the overhead bridge 
crane onto or against a loaded naval SNF cask (Rooms 1057 
and 1058). 
DTF-NSNFR-CC15 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC6. Preventive Procedural 
Safety 
16. Collision of a trolley holding a naval SNF cask on a pedestal with 
shield doors separating the WP/navy to trolley transfer room and 
the WP/navy cask preparation room (Room 1057). 
DTF-NSNFR-CC16 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
17.Closing of the shield doors separating the WP/navy to trolley 
transfer room and the WP/navy cask preparation room on a trolley 
holding a naval SNF cask on a pedestal (Room 1057). 
DTF-NSNFR-CC17 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC3. Preventive Design 
18.Derailment of a trolley holding a naval SNF cask on a pedestal 
followed by a load tipover or fall (Room 1057). 
DTF-NSNFR-CC18 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a forklift (Room 1058). DTF-NSNFR-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-50 April 2005 
Table III-12. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval SNF Receipt): Waste Package and Navy Cask Entrance Vestibule. (Room 1060), Waste Package/Navy Cask SRTC Receipt Area. (Room 1058), Waste 
Package/Navy to Trolley Transfer Room. (Room 1057), Waste Package/Navy Cask Preparation Room (Room 1053) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1058). 
DTF-NSNFR-EI2 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the WP/navy cask SRTC receipt 
area overhead cranes (Rooms 1057 and 1058). 
DTF-NSNFR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
electrical equipment in the WP/navy cask SRTC receipt area, WP 
and navy cask entrance vestibule, the WP/navy to trolley transfer 
room, or the WP/navy cask preparation room (Rooms 1057 and 
1058). 
DTF-NSNFR-FT2 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-FT1. Preventive Design- 
Procedural 
Safety 
3. Diesel fuel fire/explosion involving an SRTC tractor pulling or 
pushing an SRTC holding a naval SNF cask containing a naval 
SNF canister (Rooms 1058 and 1060).. 
DTF-NSNFR-FT3 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-FT1. Preventive Design- 
Procedural 
Safety 
4. Electrical fire associated with a trolley holding a naval SNF cask 
containing a naval SNF canister (Room 1057). 
DTF-NSNFR-FT4 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-FT1. Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with a forklift 
(Room 1058). 
DTF-NSNFR-FT5 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with a mobile 
elevated platform (Room 1058). 
DTF-NSNFR-FT6 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-FT1. Preventive Design- 
Procedural 
Safety 
7. Transient combustible fire in the WP and navy cask entrance 
vestibule, the WP/navy cask SRTC receipt area, the WP/navy to 
trolley transfer room, or the WP/navy cask preparation room 
(Rooms 1057, 1058, and 1060). 
DTF-NSNFR-FT7 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-FT1. Preventive Design- 
Procedural 
Safety 
8. Thermal hazard (from decay heat) associated with a vertical 
orientation of a loaded naval SNF cask (Rooms 1057, 1058, 
and 1060). 
DTF-NSNFR-FT8 Beyond Category 2 This potential event does not lead to exposure of individuals to radiation because the naval 
SNF is contained in a sealed canister. 
Preventive Design 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1057, 1058, and 1060). 
DTF-NSNFR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1057, 1058, and 1060). 
DTF-NSNFR-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Radiation-induced damage to a facility SSC (Rooms 1057, 1058, 
and 1060). 
DTF-NSNFR-R3 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-51 April 2005 
Table III-12. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval SNF Receipt): Waste Package and Navy Cask Entrance Vestibule. (Room 1060), Waste Package/Navy Cask SRTC Receipt Area. (Room 1058), Waste 
Package/Navy to Trolley Transfer Room. (Room 1057), Waste Package/Navy Cask Preparation Room (Room 1053) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Fissile 1. Criticality associated with an SRTC derailment or collision 
followed by a load tipover or fall and a rearrangement of the naval 
SNF cask internals (Rooms 1058 and 1060). 
DTF-NSNFR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a naval SNF cask drop, slapdown, or 
collision and rearrangement of cask internals (Rooms 1057, 1058, 
and 1060). 
DTF-NSNFR-F2 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-F1. Preventive Design 
3. Criticality associated with naval SNF cask trolley derailment 
followed by a load tipover or fall and a rearrangement of the cask 
internals (Room 1057). 
DTF-NSNFR-F3 Beyond Category 2 Same disposition as Potential Event DTF-NSNFR-CC18. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; NA = not applicable; NSNFR = naval SNF cask receipt; R = radiation; 
SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example NSNFR, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-52 April 2005 
Table III-13. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval Spent Nuclear Fuel Processing): Waste Package Docking Cell (Rooms 1052 and 1055), Waste Package Loading (Navy Canister)/Docking Ring 
Removal Cell (Room 1051) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a loaded naval SNF cask on a 
pedestal followed by a load tipover or fall (Rooms 1051, 1052, 
1053, and 1055). 
DTF-NSNFP-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Drop or collision of handling equipment (such as the lid grapple) 
onto or against a naval SNF cask outer lid (if applicable) or inner 
lid (Rooms 1051, 1052, 1053, and 1055). 
DTF-NSNFP-CC2 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, do not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
3. Drop of a naval SNF cask inner lid (if applicable) from the 70-ton 
navy canister handling crane onto a naval SNF canister 
(Room 1051). 
DTF-NSNFP-CC3A 
DTF-NSNFP-CC3B 
No drop 
Category 2 
(See GET-02 Sequences A and B only) Design and operational requirements reduce the 
drop probability. 
Preventive Design- 
Procedural 
Safety 
4. Drop or collision of handling equipment (such as a canister 
grapple) into or against an open naval SNF cask loaded with a 
naval SNF canister (Rooms 1051, 1052, 1053, and 1055). 
DTF-NSNFP-CC4A 
DTF-NSNFP-CC4B 
No drop 
Category 2 
(See GET-06 Sequences A and B only) In this potential event, a drop has to occur to cause 
a collision because the equipment would be suspended above the canister. Design and 
operational requirements reduce the drop probability. 
Preventive Design- 
Procedural 
Safety 
5. Drop or collision of a naval SNF canister from the WP docking cell 
crane back into or against the naval SNF cask being unloaded 
(Rooms 1052 and 1055). 
DTF-NSNFP-CC5A 
DTF-NSNFP-CC5B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
6. Fall of a naval SNF canister from the WP docking crane onto the 
edge of the cask, the edge of the WP, or the edge of the transfer 
floor, followed by a slapdown of the canister (Rooms 1052 and 
1055). 
DTF-NSNFP-CC6A 
DTF-NSNFP-CC6B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTF-NSNFPCC5. 
Preventive Design- 
Procedural 
Safety 
7. Drop or collision of a naval SNF canister from the 70-ton navy 
canister handling crane onto or against a sharp object 
(Room 1051). 
DTF-NSNFP-CC7 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-53 April 2005 
Table III-13. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval SNF Processing): Waste Package Docking Cell (Rooms 1052 and 1055), Waste Package Loading (Navy Canister)/Docking Ring Removal Cell (Room 
1051) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Collision involving a naval SNF canister suspended from the 70- 
ton navy canister handling crane with equipment located in the 
WP docking cell or the WP loading (navy canister)/docking ring 
removal cell, such as lid lifting equipment (Rooms 1051, 1052, 
and 1055). 
DTF-NSNFP-CC8 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
9. Drop of a naval SNF canister from the 70-ton navy canister 
handling crane onto the navy transfer/docking ring removal cell 
floor (Room 1051). 
DTF-NSNFP-CC9A 
DTF-NSNFP-CC9B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTF-NSNFPCC5. 
Preventive Design- 
Procedural 
Safety 
10.Impact due to horizontal movement of the naval SNF canister 
before it is completely removed from the naval transportation cask 
(Rooms 1051, 1052, 1053, and 1055). 
DTF-NSNFP-CC10A Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force to 
breach a transportation cask, MSC, waste package, or canister as the result of attempts to 
overcome mechanical constraints. 
Preventive Design 
11.Drop or collision of a naval SNF canister from the 70-ton navy 
canister handling crane into or against the WP (Room 1051). 
DTF-NSNFP-CC11A 
DTF-NSNFP-CC11B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTF-NSNFPCC5. 
Preventive Design- 
Procedural 
Safety 
12.Drop or collision of handling equipment into or against an open 
WP loaded with a naval SNF canister (Room 1051). 
DTF-NSNFP-CC12A 
DTF-NSNFP-CC12B 
No drop 
Category 2 
(See GET-06 Sequences A and B only) Same disposition as Potential Event DTF-NSNFPCC4. 
Preventive Design- 
Procedural 
Safety 
13.Drop of a WP inner lid from the WP docking cell crane into a 
loaded naval WP (Rooms 1052 and 1055). 
DTF-NSNFP-CC13A 
DTF-NSNFP-CC13B 
No drop 
Category 2 
(See GET-02 Sequences A and B only) Same disposition as Potential Event DTF-NSNFPCC3. 
Preventive Design- 
Procedural 
Safety 
Explosion-Implosion No events. 
Fire-Thermal 1. Electrical fire associated with SNF handling equipment in the WP 
docking cell and the WP loading (naval SNF canister)/docking ring 
removal cell (including the overhead crane, etc.) (Rooms 1051, 
1052, 1053, and 1055). 
DTF-NSNFP-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with the trolley holding either a loaded, 
unsealed WP or a loaded naval SNF cask holding a naval SNF 
canister (Rooms 1051, 1052, 1053, and 1055). 
DTF-NSNFP-FT2 Beyond Category 2 Same disposition as Potential Event DTF-NSNFP-FT1. Preventive Design- 
Procedural 
Safety 
3. Thermal hazard (from decay heat) associated with a vertical 
orientation of the naval SNF cask (Rooms 1051, 1052, 1053, 
and 1055). 
DTF-NSNFP-FT3 Beyond Category 2 This potential event will not cause oxidation of SNF leading to exposure of individuals to 
radiation because naval SNF is handled in sealed canisters. 
Preventive Design 
4. Overheating of a loaded, unsealed (and uninerted) cask or WP 
due to a loss of cooling resulting in excessive temperature and 
possible damage to canister contents (Rooms 1051, 1052, 1053, 
and 1055). 
DTF-NSNFP-FT4 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
5. Transient combustible fire in the WP docking cell or the WP 
loading (naval SNF canister)/docking ring removal cell (Rooms 
1051, 1052, 1053, and 1055). 
DTF-NSNFP-FT5 Beyond Category 2 Same disposition as Potential Event DTF-NSNFP-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-54 April 2005 
Table III-13. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Naval SNF Processing): Waste Package Docking Cell (Rooms 1052 and 1055), Waste Package Loading (Navy Canister)/Docking Ring Removal Cell (Room 
1051) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1051, 1052, 1053, and 1055). 
DTF-NSNFP-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1051, 1052, 1053, and 1055). 
DTF-NSNFP-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Inadvertent opening of a shield door, leading to a worker exposure 
(Rooms 1051, 1052, and 1053). 
DTF-NSNFP-R3 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
4. Radiation-induced damage to a facility SSC (Rooms 1051, 1052, 
1053, and 1055). 
DTF-NSNFP-R4 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a naval SNF cask drop, slapdown, or 
collision and rearrangement of cask internals (Rooms 1051, 1052, 
1053, and 1055). 
DTF-NSNFP-F1 Beyond Category 2 Criticality of a naval canister following a drop, or other impact event, has been evaluated to 
be Beyond Category 2 based upon probabilities of independent events required for 
criticality.. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; DTF = dry transfer facility (DTF 1 and DTF 2); DBGM = design basis ground motion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; NA = not applicable; 
NSNFP = naval spent nuclear fuel preparation; R = radiation; SNF = spent nuclear fuel. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example NSNFP, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-55 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Drop or collision of handling equipment into or against an open 
cask or open MSC loaded with commercial SNF assemblies, a 
DOE HLW canister, a DOE SNF MCO, or a [standardized] DOE 
SNF canister (Room 2048). 
DTF-WPTDRC-CC1aA 
DTF-WPTDRC-CC1aB 
DTF-WPTDRC-CC1aC 
DTF-WPTDRC-CC1aD 
DTF-WPTDRC-CC1aE 
DTF-WPTDRC-CC1aF 
DTF-WPTDRC-CC1bA 
DTF-WPTDRC-CC1bB 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
No drop or collision 
Category 2 
CC1a. (See GET-06 for non-commercial SNF` canisters) In this potential event, a drop has 
to occur to cause a collision because the equipment would be suspended above the 
canister. Design and operational requirements reduce the drop probability. An operational 
requirement ensures the establishment of a maximum lift height limit for handling 
equipment suspended above DOE SNF canisters. A design requirement ensures that the 
handling equipment is not capable of causing an event sequence due to a breach of a DOE 
SNF canister if dropped from within the lift-height limit. Design and operational 
requirements limit the probability of exceeding the lift height. 
CC1b. (See GET-04 for commercial SNF) An operational requirement prohibits carrying 
DOE HLW canisters or DOE SNF canisters over or near the staging racks for commercial 
SNF. Design and operational requirements reduce the probability of dropping handling 
equipment onto or against a SNF assembly energetically enough to breach the assembly. 
Preventive Design- 
Procedural 
Safety 
2. Drop or collision of an SNF assembly from the spent fuel transfer 
machine back into or against a cask or MSC being unloaded 
(Room 2048). 
DTF-WPTDRC-CC2A 
DTF-WPTDRC-CC2B 
DTF-WPTDRC-CC2C 
DTF-WPTDRC-CC2D 
DTF-WPTDRC-CC2E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Design and operational requirements for the spent fuel transfer machine (in 
the dry transfer areas) and fuel handling machine (in the pool) reduce the drop rate and 
collision probabilities for commercial SNF assembly transfers, including those in singleassembly 
canisters. Assemblies are assumed to breach when they are dropped or 
involved in a collision. HVAC system reliability requirements ensure availability of highefficiency 
particulate air filtration in the primary confinement areas of the DTF and FHF 
during a 4-h mission time without credit for backup electrical power. An operational 
requirement ensures that HVAC system is working properly before normal operations 
begin, that the HVAC system is monitored for proper operation during normal operations, 
and that normal operations are suspended if the HVAC system or offsite power becomes 
unavailable. 
Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
3. Drop or collision of an SNF assembly from the spent fuel transfer 
machine back onto or against one or more SNF assembly(ies) in a 
cask or MSC (Room 2048). 
DTF-WPTDRC-CC3A 
DTF-WPTDRC-CC3B 
DTF-WPTDRC-CC3C 
DTF-WPTDRC-CC3D 
DTF-WPTDRC-CC3E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
4. Impact due to horizontal movement of an SNF assembly by the 
spent fuel transfer machine before the assembly is completely 
removed from the cask or MSC (Room 2048). 
DTF-WPTDRC-CC4A 
DTF-WPTDRC-CC4B 
DTF-WPTDRC-CC4C 
DTF-WPTDRC-CC4D 
DTF-WPTDRC-CC4E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
5. Drop of an SNF assembly from the spent fuel transfer machine 
onto the waste transfer cell floor (Room 2048). 
DTF-WPTDRC-CC5A 
DTF-WPTDRC-CC5B 
DTF-WPTDRC-CC5C 
DTF-WPTDRC-CC5D 
DTF-WPTDRC-CC5E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-56 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
6. Collision involving an SNF assembly suspended from the spent 
fuel transfer machine with equipment located in the waste transfer 
cell or on the cell floor (such as lid lifting equipment) (Room 2048). 
DTF-WPTDRC-CC6A 
DTF-WPTDRC-CC6B 
DTF-WPTDRC-CC6C 
DTF-WPTDRC-CC6D 
DTF-WPTDRC-CC6E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
7. Drop or collision of an SNF assembly from the spent fuel transfer 
machine onto or against a sharp object (Room 2048). 
DTF-WPTDRC-CC7A 
DTF-WPTDRC-CC7B 
DTF-WPTDRC-CC7C 
DTF-WPTDRC-CC7D 
DTF-WPTDRC-CC7E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
8. Drop or collision of an SNF assembly from the spent fuel transfer 
machine into or against an empty WP or MSC being loaded 
(Room 2048). 
DTF-WPTDRC-CC8A 
DTF-WPTDRC-CC8B 
DTF-WPTDRC-CC8C 
DTF-WPTDRC-CC8D 
DTF-WPTDRC-CC8E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
9. Drop and slapdown of an SNF assembly from the spent fuel 
transfer machine (due to impact with an edge of the cask, MSC, 
WP, floor edge, WP internal baffle, staging rack, etc.) during the 
transfer from the cask or MSC to a WP or staging rack (Room 
2048). 
DTF-WPTDRC-CC9A 
DTF-WPTDRC-CC9B 
DTF-WPTDRC-CC9C 
DTF-WPTDRC-CC9D 
DTF-WPTDRC-CC9E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
10.Drop or collision of an SNF assembly from the spent fuel transfer 
machine onto or against another SNF assembly in a WP or MSC 
(Room 2048). 
DTF-WPTDRC-CC10A 
DTF-WPTDRC-CC10B 
DTF-WPTDRC-CC10C 
DTF-WPTDRC-CC10D 
DTF-WPTDRC-CC10E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
11.Drop or collision of a SNF assembly from the spent fuel transfer 
machine into or against an empty staging rack in the waste 
transfer cell. (Room 2048). 
DTF-WPTDRC-CC11A 
DTF-WPTDRC-CC11B 
DTF-WPTDRC-CC11C 
DTF-WPTDRC-CC11D 
DTF-WPTDRC-CC11E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
12.Drop or collision of a SNF assembly from the spent fuel transfer 
machine onto or against one or more SNF assemblies in a staging 
rack (Room 2048). 
DTF-WPTDRC-CC12A 
DTF-WPTDRC-CC12B 
DTF-WPTDRC-CC12C 
DTF-WPTDRC-CC12D 
DTF-WPTDRC-CC12E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DFT-WPTDRC-CC2. Preventive- 
Mitigative 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-57 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
13.Drop or collision of a SNF assembly from the spent fuel transfer 
machine onto or against a DOE HLW canister or [standardized] 
DOE SNF canister in a staging rack (Room 2048). 
DTF-WPTDRC-CC13 Beyond Category 2 An operational requirement precludes contact between a commercial SNF assembly and a 
staged canister 
Preventive Procedural 
Safety 
14.Drop or collision of a DOE HLW canister or a [standardized] DOE 
SNF canister from the waste transfer cell overhead crane back 
into or against the cask or MSC being unloaded (Room 2048). 
DTF-WPTDRC-CC14A 
DTF-WPTDRC-CC14B 
DTF-WPTDRC-CC14C 
DTF-WPTDRC-CC14D 
DTF-WPTDRC-CC14E 
DTF-WPTDRC-CC14F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Design and operational requirements reduce the drop probability. A design 
requirement limits lift heights for DOE SNF canister, DOE HLW canister, naval canisters, 
and DOE SNF multicanister overpacks. Design and operational requirements limit the 
probability of exceeding the lift height. Design requirements ensure that standardized DOE 
SNF canisters would withstand without breach a drop of another standardized DOE SNF 
canister and that MCOs would withstand without breach a drop of another MCO dropped 
from within its lift-height limits. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. Operational controls render dropping a DOE SNF canister on a DOE HLW 
canister Beyond Category 2. A design requirement ensures that a DOE SNF canister in a 
cask, WP, staging rack, or staging pit would withstand without breach the drop of a DOE 
HLW canister on top of the DOE SNF canister from within their lift height limits. Neither 
naval canisters nor MCOs are staged in staging racks. For collisions, a design requirement 
limits speed for crane transfers such that a collision at the maximum speed could not 
breach an MSC, transportation cask, transfer cask, DPC, DOE or naval canister, or waste 
package involved in the transfer. 
Preventive Design 
Procedural 
Safety 
15.Drop or collision of a DOE SNF MCO from the waste transfer cell 
overhead crane back into or against the cask being unloaded 
(Room 2048). 
DTF-WPTDRC-CC15C 
DTF-WPTDRC-CC15D 
DTF-WPTDRC-CC15E 
DTF-WPTDRC-CC15F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event DFT-WPTDRCCC14. 
Preventive Design- 
Procedural 
Safety 
16.Impact due to horizontal movement of a DOE HLW canister or a 
[standardized] DOE SNF canister with the waste transfer cell 
overhead crane before the canister is completely removed from 
the cask or MSC (Room 2048). 
DTF-WPTDRC-CC16 Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force 
during a transfer to breach a transportation cask, MSC, WP, or canister as the result of 
attempts to overcome mechanical constraints. 
Preventive Design 
17.Impact due to horizontal movement of a DOE SNF MCO with the 
waste transfer cell overhead crane before the canister is 
completely removed from the cask (Room 2048). 
DTF-WPTDRC-CC17 Beyond Category 2 Same disposition as Potential Event DFT-WPTDRC-CC16. Preventive Design 
18.Drop and slapdown of a DOE HLW canister or a [standardized] 
DOE SNF canister from the waste transfer cell overhead crane 
(due to impact with an edge of the cask, MSC, WP, floor edge, 
WP internal baffle, staging rack, etc.) during the transfer from the 
cask or MSC to a WP, or staging rack (Room 2048). 
DTF-WPTDRC-CC18A 
DTF-WPTDRC-CC18B 
DTF-WPTDRC-CC18C 
DTF-WPTDRC-CC18D 
DTF-WPTDRC-CC18E 
DTF-WPTDRC-CC18F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event DFT-WPTDRC-CC14. Preventive Design- 
Procedural 
Safety 
19.Drop and slapdown of a DOE SNF MCO from the waste transfer 
cell overhead crane (due to impact with an edge of the cask, WP, 
floor edge, WP internal baffle, etc.) during the transfer from the 
cask to a WP (Room 2048). 
DTF-WPTDRC-CC19C 
DTF-WPTDRC-CC19D 
DTF-WPTDRC-CC19E 
DTF-WPTDRC-CC19F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event DFT-WPTDRCCC14. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-58 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
20.Drop or collision of a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO from the waste transfer cell 
overhead crane onto or against a sharp object (Room 2048). 
DTF-WPTDRC-CC20 Beyond category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
21. Collision involving a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO suspended from the waste 
transfer cell overhead crane with equipment located in the waste 
transfer cell or on the cell floor, such as lid lifting equipment 
(Room 2048). 
DTF-WPTDRC-CC21 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
22.Drop of a DOE HLW canister, a [standardized] DOE SNF canister, 
or a DOE SNF MCO from the waste transfer cell overhead crane 
onto the waste transfer cell floor (Room 2048). 
DTF-WPTDRC-CC22A 
DTF-WPTDRC-CC22B 
DTF-WPTDRC-CC22C 
DTF-WPTDRC-CC22D 
DTF-WPTDRC-CC22E 
DTF-WPTDRC-CC22F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event DFT-WPTDRC-CC14. Preventive Design- 
Procedural 
Safety 
23.Drop or collision of a DOE HLW canister or a [standardized] DOE 
SNF canister from the waste transfer cell crane into or against an 
empty canister staging rack (Room 2048). 
DTF-WPTDRC-CC23A 
DTF-WPTDRC-CC23B 
DTF-WPTDRC-CC23C 
DTF-WPTDRC-CC23D 
DTF-WPTDRC-CC23E 
DTF-WPTDRC-CC23F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 ) Same disposition as Potential Event DFT-WPTDRC-CC14. Preventive Design- 
Procedural 
Safety 
24.Drop or collision of a DOE HLW canister or a [standardized] DOE 
SNF canister from the waste transfer cell crane into or against an 
SNF assembly staging rack loaded with SNF assemblies (Room 
2048). 
DTF-WPTDRC-CC24 Beyond category 2 An operational requirement prohibits carrying DOE HLW canisters or DOE SNF canisters 
over or near the staging racks for commercial SNF. 
Preventive Procedural 
Safety 
25.Drop or collision of a DOE HLW canister or a [standardized] DOE 
SNF canister from the waste transfer cell crane onto or against 
another DOE HLW canister or DOE SNF canister in a staging rack 
(Room 2048). 
DTF-WPTDRC-CC25A 
DTF-WPTDRC-CC25B 
DTF-WPTDRC-CC25C 
DTF-WPTDRC-CC25D 
DTF-WPTDRC-CC25E 
DTF-WPTDRC-CC25F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event DFT-WPTDRC-CC14. Preventive Design- 
Procedural 
Safety 
26.Drop or collision of a DOE HLW canister or a [standardized] DOE 
SNF canister from the waste transfer cell crane into or against an 
empty WP or into or against an empty MSC being loaded 
(Room 2048). 
DTF-WPTDRC-CC26A 
DTF-WPTDRC-CC26B 
DTF-WPTDRC-CC26C 
DTF-WPTDRC-CC26D 
DTF-WPTDRC-CC26E 
DTF-WPTDRC-CC26F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event DFT-WPTDRC-CC14. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-59 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
27.Drop or collision of a DOE SNF MCO from the waste transfer cell 
crane into or against an empty WP being loaded (Room 2048). 
DTF-WPTDRC-CC27C 
DTF-WPTDRC-CC27D 
DTF-WPTDRC-CC27E 
DTF-WPTDRC-CC27F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event DFT-WPTDRCCC14. 
Preventive Design- 
Procedural 
Safety 
28.Drop or collision of a DOE HLW canister from the waste transfer 
cell crane onto or against another DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO in a WP 
being loaded (Room 2048). 
DTF-WPTDRC-CC28A 
DTF-WPTDRC-CC28B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
29.Drop or collision of a DOE HLW canister from the waste transfer 
cell crane onto or against another DOE HLW canister or a 
[standardized] DOE SNF canister in a WP or in an MSC being 
loaded (Room 2048). 
DTF-WPTDRC-CC29A 
DTF-WPTDRC-CC29B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DFTWPTDRC-
CC28. 
Preventive Design- 
Procedural 
Safety 
30.Drop or collision of a DOE SNF canister from the waste transfer 
cell crane onto or against a DOE HLW canister in a WP or in an 
MSC (Room 2048). 
DTF-WPTDRC-CC30 Beyond Category 2 Dropping a DOE SNF canister on a DOE HLW canister is rendered beyond Category 2 by 
an operational requirement to not transfer or remove the DOE SNF canister into or from the 
waste package or site-specific cask if there are one or more DOE HLW canisters present in 
the waste package or site-specific cask. For collisions, a design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
31.Drop or collision of a DOE SNF MCO from the waste transfer cell 
crane onto or against another DOE SNF MCO or a DOE HLW 
canister in a WP being loaded (Room 2048). 
DTF-WPTDRC-CC31 Beyond Category 2 Same disposition as Potential Event DFT-WPTDRC-CC30. Additionally, a design 
requirement ensures that MCOs would withstand without breach a drop of another MCO 
dropped from within its lift height limit. 
Preventive Design- 
Procedural 
Safety 
32.Drop or collision of a DOE SNF canister from the waste transfer 
cell crane onto or against another [standardized] DOE SNF 
canister in a WP or in an MSC in a misload situation 
(Room 2048). 
DTF-WPTDRC-CC32C 
DTF-WPTDRC-CC32D 
DTF-WPTDRC-CC32E 
DTF-WPTDRC-CC32F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 
(See GET-05 Sequences C to F only) Same disposition as Potential Event DFT-WPTDRCCC14. 
Preventive Design- 
Procedural 
Safety 
33.Drop or collision of a DOE SNF MCO from the waste transfer cell 
crane onto or against a [standardized] DOE SNF canister in a WP 
in a misload situation (Room 2048). 
DTF-WPTDRC-CC33C 
DTF-WPTDRC-CC33D 
DTF-WPTDRC-CC33E 
DTF-WPTDRC-CC33F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 
(See GET-05 Sequences C to F only) Same disposition as Potential Event DFT-WPTDRCCC14. 
Preventive Design- 
Procedural 
Safety 
34.Drop or collision of a DOE HLW canister, a [standardized] DOE 
SNF canister, or a DOE SNF MCO from the waste transfer cell 
crane onto or against SNF assemblies in a WP or in an MSC in a 
misload situation (Room 2048). 
DTF-WPTDRC-CC34 Beyond Category 2 This potential event requires, in addition to a dropped canister, an attempt to load a 
canister into a waste package or site-specific cask designed for bare SNF assemblies. An 
operational requirement ensures that drops of a DOE canister into a waste package or sitespecific 
cask loaded with SNF assemblies are rendered Beyond Category 2. For collisions, 
a design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Procedural 
Safety 
35.Drop or collision of a SNF assembly from the spent fuel transfer 
machine onto or against a DOE HLW canister or a [standardized] 
DOE SNF canister in a WP or in an MSC in a misload situation 
(Room 2048). 
DTF-WPTDRC-CC35 Beyond Category 2 This potential event requires, in addition to a dropped assembly, an attempt to load an SNF 
assembly into a waste package or site-specific cask designed for canisters. An operational 
requirement ensures that drops of a commercial SNF assembly into a waste package or 
site-specific cask loaded with DOE canisters are rendered Beyond Category 2. 
Preventive Procedural 
Safety 
36.Drop or collision of a SNF assembly from the spent fuel transfer 
machine onto or against a DOE HLW canister or a DOE SNF 
MCO in a WP in a misload situation (Room 2048). 
DTF-WPTDRC-CC36 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-CC35. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-60 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
37. Drop or collision of handling equipment onto or against SNF 
assemblies in the SNF staging rack (Room 2048). 
DTF-WPTDRC-CC37A 
DTF-WPTDRC-CC37B 
No drop or collision 
Category 2 
(See GET-04) An operational requirement prohibits carrying DOE HLW canisters or DOE 
SNF canisters over or near the staging racks for commercial SNF. Design and operational 
requirements reduce the probability of dropping handling equipment onto or against a SNF 
assembly energetically enough to breach the assembly. 
Preventive Design- 
Procedural 
Safety 
38.Drop or collision of handling equipment onto or against a DOE 
HLW canister or a [standardized] DOE SNF canister in a canister 
staging rack (Room 2048). 
DTF-WPTDRC-CC38A 
DTF-WPTDRC-CC38B 
DTF-WPTDRC-CC38C 
DTF-WPTDRC-CC38D 
DTF-WPTDRC-CC38E 
DTF-WPTDRC-CC38F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) Same disposition as Potential Event DTF-WPTDRC-CC1a. Preventive Design- 
Procedural 
Safety 
39.Drop or collision of handling equipment into or against an open 
MSC or an open WP filled with SNF assemblies (Room 2048). 
DTF-WPTDRC-CC39A 
DTF-WPTDRC-CC39B 
No drop or collision 
Category 2 
(See GET-04) Same disposition as Potential Event DTF-WPTDRC-CC37. Preventive Design- 
Procedural 
Safety 
40.Drop or collision of handling equipment into or against an open 
WP loaded with SNF assemblies, DOE HLW canisters, and/or a 
[standardized] DOE SNF canister, and/or DOE SNF MCOs (Room 
2048). 
DTF-WPTDRC-CC40A 
DTF-WPTDRC-CC40B 
DTF-WPTDRC-CC40C 
DTF-WPTDRC-CC40D 
DTF-WPTDRC-CC40E 
DTF-WPTDRC-CC40F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 
(See GET-06) Same disposition as Potential Event DTF-WPTDRC-CC1a. Preventive Design- 
Procedural 
Safety 
41.Drop or collision of a WP inner lid or MSC cask inner lid from the 
docking station crane onto or against a loaded WP or loaded MSC 
(Room 2048). 
DTF-WPTDRC-CC41A 
DTF-WPTDRC-CC41B 
DTF-WPTDRC-CC41C 
DTF-WPTDRC-CC41D 
DTF-WPTDRC-CC41E 
DTF-WPTDRC-CC41F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
42.Drop or collision of a WP docking port plug from the waste 
transfer cell crane onto or against the inner lid of a loaded WP or 
loaded MSC (with lid in place but not sealed). (Room 2048). 
DTF-WPTDRC-CC42 Beyond Category 2 Design requirements ensure that portions of a non-ITS SSC which, upon failure, could 
adversely interact with an ITS SSC and prevent its safety function from being performed 
are classified as ITS, redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC, or, for seismic interactions, designed to the same seismic DBGM as 
the ITS SSCs subjected to the potential unacceptable interaction. 
Preventive Design 
43.Drop or collision of a WP docking ring onto or against a loaded 
WP (with lid in place but not sealed) during docking ring removal 
in the WP loading/docking ring removal cell (Room 1054). 
DTF-WPTDRC-CC43 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
44.Drop or collision of a handling or other miscellaneous equipment 
onto or against a loaded WP (with lid in place but not sealed) 
during docking ring removal in the WP loading/docking ring 
removal cell (Room 1054). 
DTF-WPTDRC-CC44 Beyond Category 2 The inner lid is in place for this potential event. Same disposition as Potential Event DTFWPTDRC-
CC43. 
Preventive Procedural 
Safety 
45.Derailment of a trolley holding a loaded, unsealed WP (with lid in 
place but not sealed) followed by a load tipover or fall 
(Rooms 1052, 1054, and 1055). 
DTF-WPTDRC-CC45 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-61 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1052, 1054, 1055, 1069, 
and 2048). 
DTF-WPTDRC-CCF1 Normal Operations Oxidation of failed SNF is to be expected as a part of normal operations. Any resulting 
potential exposure of workers to radiation is managed as a normal-operations dose by 
procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a cask trolley 
(Rooms 1052, 1054, 1055, and 1069). 
DTF-WPTDRC-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
Fire-Thermal 1. HEPA filter fire due to excessive radioactive decay within the filter 
bed (Room 1012). 
DTF-WPTDRC-FT1 Beyond Category 2 Operation requirements ensure that the operating surface temperatures of high-efficiency 
particulate air (HEPA) filters is maintained such that they can not catch on fire under 
normal operation or in the event of a shutdown of the HVAC system. 
Preventive Procedural 
Safety 
2. Electrical fire associated with SNF and HLW handling equipment 
or other electrically powered equipment in the waste transfer cell, 
the WP docking cell, or the WP loading/docking ring removal cell 
(including the overhead cranes and the spent fuel transfer 
machine). (Rooms 1052, 1054, 1055, 1069, and 2048). 
DTF-WPTDRC-FT2 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) associated with a cask trolley 
holding a an unsealed, partially-filled or filled cask or MSC 
(Rooms 1052, 1054, 1055, and 1069). 
DTF-WPTDRC-FT3 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-FT2. Preventive Design- 
Procedural 
Safety 
4. Electrical fire associated with a WP trolley holding an unsealed, 
partially-filled or filled WP (Rooms 1052, 1054, and 1055). 
DTF-WPTDRC-FT4 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-FT2. Preventive Design- 
Procedural 
Safety 
5. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
(Rooms 1052, 1054, 1055, 1069, and 2048). 
DTF-WPTDRC-FT5 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
6. Transient combustible fire in the cask and MSC docking room, 
waste transfer cell, the WP docking cell, or the WP 
loading/docking ring removal cell (Rooms 1052, 1054, 1055, 
1069, and 2048). 
DTF-WPTDRC-FT6 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-FT2. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1052, 1054, 1055, 1069, and 2048). 
DTF-WPTDRC-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Docking ring failure leads to a radiological release (Room 2048). DTF-WPTDRC-R2 NA (no significant 
exposure) 
Same disposition as Potential Event DTF-WPTDRC-R4. Mitigative Procedural 
Safety 
3. Radiological release due to installation of incorrect docking ring 
(Room 2048). 
DTF-WPTDRC-R3 NA (no significant 
exposure) 
Same disposition as Potential Event DTF-WPTDRC-R4. Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-62 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
4. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne contamination (Rooms 1052, 1054, 1055, 1069, 
and 2048). 
DTF-WPTDRC-R4 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
5. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Rooms 
1052, 1054, 1055, and 1069). 
DTF-WPTDRC-R5 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
6. Inadvertent opening of a shield door, leading to a worker exposure 
(Room 1052, 1054, 1055, and 1069). 
DTF-WPTDRC-R6 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
7. Radiation-induced damage to a facility SSC (Rooms 1052, 1054, 
1055, 1069, and 2048). 
DTF-WPTDRC-R7 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine into a cask, MSC, or WP and a 
rearrangement of the cask, MSC, or WP internals (Room 2048). 
DTF-WPTDRC-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. A design requirement ensures that sealed WPs are designed such that drops, 
collisions, and other handling impacts within their design bases (allowing for rearrangement 
of container internals, proximity of other sealed waste packages, and without credit for 
burnup) cannot lead to a nuclear criticality. An unsealed waste package remains subcritical 
with credit for moderator control and without credit for burnup. Design and operational 
requirements ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
2. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine and a rearrangement of the fuel rods 
that comprise the assembly due to impact t (Room 2048). 
DTF-WPTDRC-F2 NA Results of criticality analyses ensure that drops, collisions, and other handling impacts of a 
commercial SNF assembly (allowing for rearrangement of fuel rods and without credit for 
burnup or moderator control) do not pose a criticality safety concern. 
NA NA 
3. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine onto the storage racks and a 
rearrangement of the orientation of the SNF assemblies in the 
storage racks (Room 2048). 
DTF-WPTDRC-F3 Beyond Category 2 A design requirement ensures criticality safety for commercial SNF assemblies dropped 
into or onto an SNF assembly staging rack with moderator control in effect. 
Preventive Design 
4. Criticality associated with a drop or slapdown of a [standardized] 
DOE SNF canister, a DOE SNF MCO, or a DOE HLW canister 
(Room 2048). 
DTF-WPTDRC-F4 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-F1. Additionally, an operational 
requirement prohibits carrying DOE HLW canisters or DOE SNF canisters over or near the 
staging racks for commercial SNF. There is no potential for criticality of HLW canisters. 
Preventive Design- 
Procedural 
Safety 
5. Criticality associated with the drop of heavy equipment onto a 
loaded, unsealed cask, MSC, or WP and a rearrangement of the 
container internals (Rooms 1052, 1054, 1055, 1069, and 2048). 
DTF-WPTDRC-F5 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-F1. Preventive Design- 
Procedural 
Safety 
6. Criticality associated with a misload of a WP or an MSC (Room 
2048). 
DTF-WPTDRC-F6 Beyond Category 2 Same disposition as Potential Event DTF-WPTDRC-F1. Preventive Design- 
Procedural 
Safety 
7. Criticality associated with a misload of a commercial SNF staging 
rack (Room 2048). 
DTF-WPTDRC-F7 Beyond Category 2 A design requirement ensures criticality safety for commercial SNF assembly staging racks 
loaded to capacity with the most reactive commercial SNF assembly accepted at the 
repository and not cause a nuclear criticality with moderator control in effect. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-63 April 2005 
Table III-14. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Cask and MSC Docking Room (Room 1069), Waste Transfer Cell (Room 2048), Waste Package Docking Cells (Rooms 1052 and 1055), Waste Package 
Loading/Docking Ring Removal Cell (Room 1054) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Criticality associated with a misload of a canister staging rack. 
(Room 2048). 
DTF-WPTDRC-F8 Beyond Category 2 A design requirement ensures that the most reactive configuration of standardized DOE 
SNF canisters can be loaded into DOE SNF staging racks (with credit for moderator 
control) without causing a nuclear criticality. An operational requirement ensures that 
commercial SNF assemblies are not loaded into the canister staging rack. Neither MCOs 
nor naval canisters are staged. There is no potential for criticality of HLW canisters. 
Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; DBGM = design basis ground motion; DOE = U.S. Department of Energy; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; 
HLW = high-level radioactive waste; NA =not applicable; R = radiation; SNF = spent nuclear fuel; WPTDRC = waste package transfer docking ring cell. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example WPTDRC, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
Additional room(s) with potential events in this table: Room 1012  HEPA filter room. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-64 April 2005 
Table III-15. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Empty Transportation Cask/Site-specific Cask/Dual-purpose Canister Removal): Cask and Site-specific Cask Docking Room (Room 1069), Cask/Sitespecific 
Cask Turntable Room (Room 1073), Cask Restoration Room (Room 1072), Cask and Site-specific Cask to Trolley Transfer Room (Room 1076), Cask and Site-specific Cask SRTC Receipt Area (Room 1077), Cask and 
Site-specific Cask Entrance Vestibule (Room 1079) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing No events 
Chemical Contamination- 
Flooding 
No events 
Explosion-Implosion No events 
Fire-Thermal No events 
Radiation 1. Radiation exposure of a facility worker (Rooms 1069, 1072, 1073, 
1076, 1077, and 1079). 
DTF-ETCMDR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1069, 1072, 1073, 1076, 1077, 
and 1079). 
DTF-ETCMDR-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
Fissile 1. Criticality associated with the collection and concentration of 
fissile material collected from casks during cask restoration 
activities (Rooms 1069, 1072, 1073, 1076, 1077, and 1079). 
DTF-ETCMDR-F1 Beyond Category 2 An operational requirement ensures that radioactive contamination that is collected during 
cleanup activities in transfer cells is handled in a manner that precludes nuclear criticality. 
Preventive Procedural 
Safety 
NOTES: DTF = dry transfer facility (DTF 1 and DTF 2); ETCMDR = empty transportation cask site-specific cask/dual-purpose canister removal; F = fissile; NA = not applicable; R = radiation. 
Additional room(s) with potential events in this table: Room 1079  Cask and MSC Entrance Vestibule.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-65 April 2005 
Table III-16. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Loaded Site-specific Cask Removal): Cask and Site-specific Cask Docking Room (Room 1069), Cask/Site-specific Cask Turntable Room (Room 1073), 
Cask Preparation Room (Room 1074), Cask and Site-specific Cask to Trolley Transfer Room (Room 1076), Cask and Site-specific Cask Site Rail Transfer Cart Receipt Area (Room 1077), Cask and Site-specific Cask Entrance 
Vestibule (Room 1079) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a loaded MSC on a pedestal 
followed by a load tipover or fall (before or after the outer lid [as 
applicable] is fastened) (Rooms 1069, 1072, 1073, and 1076). 
DTF-LSSCR-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Derailment of a trolley holding a loaded MSC on a pedestal due to 
a turntable malfunction followed by a load tipover or fall (before or 
after the outer lid [as applicable] is fastened). (Room 1069). 
DTF-LSSCR-CC2 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC1. Preventive Design 
3. Collision of a trolley holding a loaded MSC on a pedestal with the 
shield doors separating the cask and MSC docking room and the 
cask/MSC turntable room or the cask/MSC turntable room and the 
cask preparation room (before or after the outer lid [as applicable] 
is fastened). (Rooms 1069, 1072, and 1073). 
DTF-LSSCR-CC3 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
4. Closure of the shield doors separating the cask and MSC docking 
room and the cask/MSC turntable room or the cask/MSC turntable 
room and the cask preparation room onto the trolley holding a 
loaded MSC on a pedestal (before or after the outer lid [as 
applicable] is fastened). (Rooms 1069, 1072, and 1073). 
DTF-LSSCR-CC4 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
5. Collision involving two trolleys holding casks on pedestals 
(including a loaded MSC) (before or after the outer lid [as 
applicable] is fastened) (Rooms 1069, 1072, 1073, and 1076). 
DTF-LSSCR-CC5 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-LSSCR-CC3. Preventive Design 
6. Drop or collision of tools or equipment (including the outer lid-lifting 
fixture, inner lid-lifting fixture, lid bolts, etc.) onto or against an MSC 
inner lid or outer lid, as applicable, during the MSC lid fastening 
process. (Room 1069). 
DTF-LSSCR-CC6 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, can 
not initiate an event sequence if dropped onto or collided against (1) a transportation cask 
or site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
7. Drop of an MSC outer lid from the overhead crane onto the loaded 
MSC inner lid, as applicable (Room 1069). 
DTF-LSSCR-CC7A 
DTF-LSSCR-CC7B 
DTF-LSSCR-CC7C 
DTF-LSSCR-CC7D 
DTF-LSSCR-CC7E 
DTF-LSSCR-CC7F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. Operational requirements 
will establish permissible lift heights to ensure that a drop of a cask outer lid onto the inner 
lid of a loaded DOE SNF transportation cask or MSC will not breach a DOE SNF canister 
inside. 
Preventive Design- 
Procedural 
Safety 
8. Drop or collision of a docking ring onto or against a loaded MSC 
(Room 1069). 
DTF-LSSCR-CC8 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC6. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-66 April 2005 
Table III-16. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Loaded Site-specific Cask Removal): Cask and Site-specific Cask Docking Room (Room 1069), Cask/Site-specific Cask Turntable Room (Room 1073), Cask 
Preparation Room (Room 1074), Cask and Site-specific Cask to Trolley Transfer Room (Room 1076), Cask and Site-specific Cask Site Rail Transfer Cart Receipt Area (Room 1077), Cask and Site-specific Cask Entrance Vestibule (Room 
1079) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Collision of a trolley holding a loaded, sealed MSC on a pedestal 
with shield doors separating cask/MSC turntable room and the 
cask and MSC to trolley transfer room (Rooms 1073, 1076, and 
1077). 
DTF-LSSCR-CC9 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-LSSCR-CC3. Preventive Design 
10.Closure of the shield doors separating cask/MSC turntable room 
and the cask and MSC to trolley transfer room onto the trolley 
holding a loaded, sealed MSC on a pedestal (Rooms 1073, 1076, 
and 1077). 
DTF-LSSCR-CC10 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC4. Preventive Design 
11. Drop of a loaded, sealed MSC from the overhead crane onto the 
floor during the transfer of the MSC from a pedestal staged on a 
trolley to the floor in the lay-down area in the cask and MSC SRTC 
receipt area (Room 1077). 
DTF-LSSCR-CC11A 
DTF-LSSCR-CC11B 
DTF-LSSCR-CC11C 
DTF-LSSCR-CC11D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Design and operational requirements reduce the drop probability. 
Design requirements limit the lift height for transportation and transfer casks without 
impact limiters and site-specific casks. Design and operational requirements limit the 
probability of exceeding the lift height. Canister design requirements and the reliability of 
fabrication processes limit the probability that a DOE SNF canister or DOE multicanister 
overpack is defective. 
Preventive Design- 
Procedural 
Safety 
12.Drop or collision of a loaded MSC from the overhead crane onto or 
against a sharp object during the transfer of the MSC from a 
pedestal staged on a trolley to the floor in the lay-down area in the 
cask and MSC SRTC receipt area (Room 1077). 
DTF-LSSCR-CC12 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
13.Slapdown of a loaded, sealed MSC following a drop onto the edge 
of the pedestal, trolley, railcar or other object during the transfer of 
the MSC from a pedestal staged on a trolley to the floor in the laydown 
area in the cask and MSC SRTC receipt area (Room 1077). 
DTF-LSSCR-CC13A 
DTF-LSSCR-CC13B 
DTF-LSSCR-CC13C 
DTF-LSSCR-CC13D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event DTF-LSSCR-CC11. Preventive Design- 
Procedural 
Safety 
14.Drop or collision of handling equipment from the overhead bridge 
crane onto or against a loaded MSC (Rooms 1076 and 1077). 
DTF-LSSCR-CC14 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety 
15.Drop or collision of equipment from the 25-ton material handling 
crane onto or against a loaded, sealed MSC (Rooms 1076 and 
1077). 
DTF-LSSCR-CC15 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC14. Preventive Procedural 
Safety 
16. Forklift collision with a loaded, sealed MSC on a pedestal on a 
trolley, an MSC positioned on the floor in the lay-down area in the 
cask and MSC SRTC receipt area, or with the MSC transporter 
holding the MSC (Rooms 1077 and 1079). 
DTF-LSSCR-CC16 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a 
manner that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
17.Mobile elevated platform collision with a loaded, sealed MSC on a 
pedestal on a trolley, an MSC positioned on the floor in the laydown 
area in the cask and MSC SRTC receipt area, or with the 
MSC transporter holding the MSC (Rooms 1077 and 1079). 
DTF-LSSCR-CC17 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC16. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-67 April 2005 
Table III-16. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Loaded Site-specific Cask Removal): Cask and Site-specific Cask Docking Room (Room 1069), Cask/Site-specific Cask Turntable Room (Room 1073), Cask 
Preparation Room (Room 1074), Cask and Site-specific Cask to Trolley Transfer Room (Room 1076), Cask and Site-specific Cask Site Rail Transfer Cart Receipt Area (Room 1077), Cask and Site-specific Cask Entrance Vestibule (Room 
1079) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
18. Drop of a loaded MSC from the MSC transporter onto the floor 
inside the DTF while in-transit to the SNF Aging System (Rooms 
1077 and 1079). 
DTF-LSSCR-CC18 Beyond Category 2 A design requirement ensures that site-specific casks can withstand a drop from the 
maximum handling height of a site-specific cask transporter/horizontal transfer cask trailer 
or a collision involving the MSC transporter or HTC trailer without loss of function. 
Preventive Design 
19.Drop or collision of a loaded MSC from the MSC transporter onto or 
against a sharp object inside the DTF while in-transit to the SNF 
Aging System (Rooms 1077 and 1079). 
DTF-LSSCR-CC19 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC18. Additionally, design requirements 
limit potential damage caused by collisions involving a MSC Transporter and HTC 
Trailer/Tractor. Design requirements ensure that the SNF aging system provides a reliable 
means to stop the site-specific cask transporter-horizontal transfer cask trailer and 
maintain its stability. 
Preventive Design 
20.MSC transporter collision while carrying a loaded, sealed MSC 
followed by an MSC tipover or fall (Rooms 1077 and 1079). 
DTF-LSSCR-CC20 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC19. Additionally, design 
requirements preclude tip-over of the MSC transporter and HTC trailer/tractor during 
transfer by ensuring that designs preclude failure modes that could result in tip-over under 
design basis load handling conditions. Design requirements preclude tip-over during 
transfer by ensuring minimum tip-over resistance/stability standards are maintained 
consistent with roadway design. 
Preventive Design 
21.MSC transporter collision into a loaded, sealed MSC followed by an 
MSC tipover or fall (Rooms 1077 and 1079). 
DTF-LSSCR-CC21 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC20. Preventive Design 
22. Collision of the MSC transporter (holding a loaded, sealed MSC) 
with the cask and MSC SRTC receipt area shield doors or the cask 
and MSC entrance vestibule doors (Rooms 1077 and 1079). 
DTF-LSSCR-CC22 Beyond Category 2 Design and operational requirements establish speed limits such that a collision with shield 
or airlock doors or other heavy objects would not overturn an SRTC, or site-specific cask 
transporter or cause it to lose its load. 
Preventive Design- 
Procedural 
Safety 
23.The cask and MSC SRTC receipt area shield doors or the cask and 
MSC entrance vestibule doors close on the MSC transporter 
holding a loaded, sealed MSC (Rooms 1077 and 1079). 
DTF-LSSCR-CC23 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC4. Preventive Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures(Rooms 1069, 1072, 1073, 1076, 
1077, and 1079). 
DTF-LSSCR-CCF1 Normal Operations Oxidation of failed commercial SNF, not contained inside a sealed cask or canister, 
is expected as a part of normal operations whenever commercial SNF is exposed to air. 
Any resulting potential exposure of workers to radiation is managed as a normaloperations 
dose by procedures that ensure that workers do not receive excessive radiation 
doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. MSC inerting system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Rooms 1069, 1072, 1073, 1076, 1077, and 1079). 
DTF-LSSCR-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a cask trolley 
(Rooms 1069, 1072, 1073, and 1076). 
DTF-LSSCR-EI2 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a mobile elevated 
platform (Rooms 1076 and 1077). 
DTF-LSSCR-EI3 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-EI2. Preventive Procedural 
Safety 
4. Hydrogen explosion involving batteries on a forklift (Rooms 1077 
and 1079). 
DTF-LSSCR-EI4 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-EI2. Preventive Procedural 
Safety 
5. Explosion hazard associated with the cask purging system and the 
ignition of hydrogen that may have accumulated in the cask prior to 
MSC purging and inerting (Rooms 1069 and 1072). 
DTF-LSSCR-EI5 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-68 April 2005 
Table III-16. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Loaded Site-specific Cask Removal): Cask and Site-specific Cask Docking Room (Room 1069), Cask/Site-specific Cask Turntable Room (Room 1073), Cask 
Preparation Room (Room 1074), Cask and Site-specific Cask to Trolley Transfer Room (Room 1076), Cask and Site-specific Cask Site Rail Transfer Cart Receipt Area (Room 1077), Cask and Site-specific Cask Entrance Vestibule (Room 
1079) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Fire-Thermal 1. Electrical fire associated with the overhead cranes, including those 
located in the cask and MSC docking room and the cask and MSC 
SRTC receipt area (Rooms 1069, 1072, 1073, 1076, and 1077). 
DTF-LSSCR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
equipment located in the cask and MSC docking room, cask/MSC 
turntable room, cask and MSC to trolley transfer room, cask 
preparation room, cask and MSC SRTC receipt area, or the cask 
and MSC entrance vestibule (including the turntables) (Rooms 
1069, 1072, 1073, 1076, 1077, and 1079). 
DTF-LSSCR-FT2 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-FT1. Preventive Design- 
Procedural 
Safety 
3. Transient combustible fire in the cask and MSC docking room, 
cask/MSC turntable room, cask preparation room, cask and MSC 
to trolley transfer room, cask and MSC SRTC receipt area, or the 
cask and MSC entrance vestibule (Rooms 1069, 1072, 1073, 1076, 
1077, and 1079). 
DTF-LSSCR-FT3 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) associated with the cask 
trolley (Rooms 1069, 1072, 1073, and 1076). 
DTF-LSSCR-FT4 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-FT1. Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with a forklift 
(Rooms 1077 and 1079). 
DTF-LSSCR-FT5 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with a mobile 
elevated platform (Rooms 1076 and 1077). 
DTF-LSSCR-FT6 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-FT1. Preventive Design- 
Procedural 
Safety 
7. Diesel fuel fire/explosion involving an MSC transporter holding a 
loaded MSC (Rooms 1077 and 1079). 
DTF-LSSCR-FT7 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1069, 1072, 1073, 1076, 1077, and 1079). 
DTF-LSSCR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Damage or rupture of cask inerting system leading to a release of 
MSC internal gases (Rooms 1069 and 1072). 
DTF-LSSCR-R2 Normal Operations Although a rupture leading to a radiological release would be an off-normal occurrence, 
any release and related dose would be managed as part of routine radiation protection 
operations. Potential exposure of workers to radiation as a result of this event is managed 
as a normal-operations dose by procedures that ensure that workers do not receive 
excessive radiation doses. 
Mitigative Procedural 
Safety 
3. Expansion of gases in the loaded, unsealed MSC, leading to 
radiological release (Rooms 1069 and 1072). 
DTF-LSSCR-R3 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normaloperations 
dose by procedures that ensure that workers do not receive excessive radiation 
doses. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-69 April 2005 
Table III-16. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Loaded Site-specific Cask Removal): Cask and Site-specific Cask Docking Room (Room 1069), Cask/Site-specific Cask Turntable Room (Room 1073), Cask 
Preparation Room (Room 1074), Cask and Site-specific Cask to Trolley Transfer Room (Room 1076), Cask and Site-specific Cask Site Rail Transfer Cart Receipt Area (Room 1077), Cask and Site-specific Cask Entrance Vestibule (Room 
1079) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
4. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1069, 1072, 1073, 1076, 1077, 
and 1079). 
DTF-LSSCR-R4 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1069, 1072, 
1073, 1076, 1077, and 1079). 
DTF-LSSCR-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with an MSC collision or trolley derailment 
followed by a load tipover or fall and a rearrangement of the MSC 
internals (before or after the outer lid [as applicable] is fastened) 
(Rooms 1069, 1072, 1073, and 1076). 
DTF-LSSCR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a drop or slapdown of a loaded, sealed 
MSC from an overhead crane and a rearrangement of cask 
internals (Rooms 1076 and 1077). 
DTF-LSSCR-F2 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-F1. Preventive Design 
3. Criticality associated with an MSC transporter collision while 
holding a loaded, sealed MSC followed by a load tipover or fall and 
rearrangement of the cask internals (Rooms 1077 and 1079). 
DTF-LSSCR-F3 Beyond Category 2 Same disposition as Potential Event DTF-LSSCR-CC1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; DOE = U.S. Department of Energy; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; 
LSSCR = loaded site-specific cask removal; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example LSSCR, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
Additional room(s) with potential events in this table: Room 1072  Cask Restoration Room. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-70 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells 
(Rooms 2032, 2033, and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the trolley holding the loaded, unsealed WP 
and the shield doors between the WP loading/docking ring 
removal cell and the WP handling and staging cell (Room 1044). 
DTF-WPHSPCD-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. Shield doors between the WP loading/docking ring removal cell 
and the WP handling and staging cell close on the trolley holding 
the loaded, unsealed WP (Room 1044). 
DTF-WPHSPCD-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of a trolley holding a loaded, unsealed WP followed by 
a load tipover or fall (Rooms 1039, 1040, 1041, 1044, and 1094). 
DTF-WPHSPCD-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
4. Drop of a loaded, unsealed WP from the WP handling and staging 
cell overhead crane onto the floor during the transfer from the 
waste transfer area pedestal and trolley to a WP positioning cell 
pedestal and trolley (Room 1044). 
DTF-WPHSPCD-CC4A 
DTF-WPHSPCD-CC4B 
DTF-WPHSPCD-CC4C 
DTF-WPHSPCD-CC4D 
DTF-WPHSPCD-CC4E 
No drop 
Category 2 
No Breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Design and operational requirements reduce the drop probability. Design 
and operational requirements specify lift-height limits for unsealed waste packages 
whenever waste packages are transferred. If the limit can not be met, impact absorbers 
are provided. Design and operational requirements limit the probability of exceeding the 
lift-height limit. Canister design requirements and the reliability of fabrication processes limit 
the probability that a DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
5. Drop of a loaded, unsealed WP from the WP handling and staging 
cell overhead crane onto a pedestal on a trolley during the 
transfer from the waste transfer area pedestal and trolley to a WP 
positioning cell pedestal and trolley (Room 1044). 
DTF-WPHSPCD-CC5A 
DTF-WPHSPCD-CC5B 
DTF-WPHSPCD-CC5C 
DTF-WPHSPCD-CC5D 
DTF-WPHSPCD-CC5E 
No Drop 
Category 2 
No Breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event DTF-WPHSPCD-CC4. Preventive Design- 
Procedural 
Safety 
6. Drop or collision of a loaded, unsealed WP from the WP handling 
and staging cell overhead crane onto or against a sharp object 
during the transfer from the waste transfer area pedestal and 
trolley to a WP positioning cell pedestal and trolley (Room 1044). 
DTF-WPHSPCD-CC6 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
7. Slapdown of a loaded, unsealed WP from the WP handling and 
staging cell overhead crane (due to impact with a 
curb/berm/impact limiter used to maintain drop height limits) or 
pedestal edge during the transfer from the waste transfer area 
pedestal and trolley to a WP positioning cell pedestal and trolley 
(Room 1044). 
DTF-WPHSPCD-CC7A 
DTF-WPHSPCD-CC7B 
DTF-WPHSPCD-CC7C 
DTF-WPHSPCD-CC7D 
DTF-WPHSPCD-CC7E 
No Drop 
Category 2 
No Breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event DTF-WPHSPCD-CC4. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-71 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Drop or collision of equipment (handling equipment, etc.) from the 
WP handling and staging cell overhead crane onto or against a 
loaded, unsealed WP positioned on a pedestal on a trolley 
(Room 1044). 
DTF-WPHSPCD-CC8 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
9. Collision involving the trolley holding the loaded, unsealed WP 
and the shield doors between WP handling and staging cell and 
the WP positioning cell (Rooms 1039, 1040, 1041, and 1044). 
DTF-WPHSPCD-CC9 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-WPHSPCD-CC1. Preventive Design 
10.Shield doors between the WP handling and staging cell and the 
WP positioning cell close on the trolley holding the loaded, 
unsealed WP (Rooms 1039, 1040, 1041, and 1044). 
DTF-WPHSPCD-CC10 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC2. Preventive Design 
11. Lid drop onto a WP from the lid placement fixture equipment 
during the welding process (Rooms 1039, 1040, 1041, 2032, 
2033, and 2035). 
DTF-WPHSPCD-CC11A 
DTF-WPHSPCD-CC11B 
DTF-WPHSPCD-CC11C 
DTF-WPHSPCD-CC11D 
DTF-WPHSPCD-CC11E 
DTF-WPHSPCD-CC11F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
12.Equipment drop onto a WP during the welding process 
(Rooms 1039, 1040, 1041, 2032, 2033, and 2035). 
DTF-WPHSPCD-CC12 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC8. Preventive Procedural 
Safety 
13.Drop or collision of equipment (handling equipment, etc.) from the 
WP handling and staging cell overhead crane onto or against a 
loaded, sealed WP positioned on a pedestal on a trolley (Room 
1044). 
DTF-WPHSPCD-CC13 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC8. Preventive Procedural 
Safety 
14. Collision involving the trolley holding the loaded, sealed WP and 
the shield doors between the WP positioning cell and the WP 
handling and staging cell (Rooms 1039, 1040, 1041, and 1044). 
DTF-WPHSPCD-CC14 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-WPHSPCD-CC1. Preventive Design 
15.Shield doors between the WP positioning cell and the WP 
handling and staging cell close on the trolley holding the loaded, 
sealed WP (Rooms 1039, 1040, 1041, and 1044). 
DTF-WPHSPCD-CC15 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC2. Preventive Design 
16.Derailment of a trolley holding a loaded, sealed WP on the rails 
leading from the WP positioning cell, followed by a load tipover or 
fall (Rooms 1039, 1040, 1041, and 1044). 
DTF-WPHSPCD-CC16 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC3. Preventive Design 
17. Drop of a loaded, sealed WP from the WP handling and staging 
cell overhead crane onto the floor during transfer from the WP 
positioning cell pedestal and trolley to the WP survey station 
(Room 1044). 
DTF-WPHSPCD-CC17A 
DTF-WPHSPCD-CC17B 
DTF-WPHSPCD-CC17C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Design and operational requirements reduce the drop probability. 
Design and operational requirements limit the lift height of waste packages in horizontal 
and vertical orientations. Design requirements ensure that waste packages withstand 
without breaching drops and tipovers within their lift height limits. Design and operational 
requirements limit the probability of exceeding the lift height. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-72 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
18.Drop or collision of a loaded, sealed WP from the WP handling 
and staging cell overhead crane onto or against a sharp object 
during transfer from the WP positioning cell pedestal and trolley to 
the WP survey station (Room 1044). 
DTF-WPHSPCD-CC18 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC6. Preventive Design- 
Procedural 
Safety 
19. Drop of a loaded, sealed WP from the WP handling and staging 
cell overhead crane onto the floor during the transfer from the WP 
survey station to a trolley for transfer to the WP loadout cell or 
during transfer to a position in a vertical orientation in a staging 
area location in the WP handling and staging cell (Room 1044). 
DTF-WPHSPCD-CC19A 
DTF-WPHSPCD-CC19B 
DTF-WPHSPCD-CC19C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Preventive Design- 
Procedural 
Safety 
20. Drop of a loaded, sealed WP from the WP handling and staging 
cell overhead crane onto a trolley during the transfer from the WP 
survey station to a trolley for transfer to the WP loadout cell 
(Room 1044). 
DTF-WPHSPCD-CC20A 
DTF-WPHSPCD-CC20B 
DTF-WPHSPCD-CC20C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Preventive Design- 
Procedural 
Safety 
21.Drop or collision of a loaded, sealed WP from the WP handling 
and staging cell overhead crane onto or against a sharp object 
during transfer from the WP survey station to a trolley for transfer 
to the WP loadout cell or during transfer to a position in a vertical 
orientation in a staging area location in the WP handling and 
staging cell (Room 1044). 
DTF-WPHSPCD-CC21 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC6. Preventive Design- 
Procedural 
Safety 
22.Slapdown of a loaded, sealed WP from the WP handling and 
staging cell overhead crane (due to impact with a 
curb/berm/impact limiter used to maintain drop height limits) or 
trolley edge during transfer from the WP survey station to a trolley 
for transfer to the WP loadout cell or during transfer to a position 
in a vertical orientation in a staging area location in the WP 
handling and staging cell (Room 1044). 
DTF-WPHSPCD-CC22A 
DTF-WPHSPCD-CC22B 
DTF-WPHSPCD-CC22C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Additionally, a 
design requirement ensures that waste packages can withstand a tipover during placement 
onto the tilting machine, including contact with trunnion cradles or the floor and a design 
requirement prevents backward slapdowns associated with the tilting machine for waste 
packages. 
Preventive Design- 
Procedural 
Safety 
23.Drop or collision of equipment (handling equipment, etc.) from the 
WP handling and staging cell overhead crane onto or against a 
loaded, sealed WP positioned in a vertical position in a staging 
area location in the WP handling and staging cell (Room 1044). 
DTF-WPHSPCD-CC23 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC8. Preventive Procedural 
Safety 
24.Drop of a loaded, partially sealed WP (WP with a known weld 
defect) from the WP handling and staging cell overhead crane 
onto the floor during the transfer from the WP positioning cell 
pedestal and trolley to a trolley for transfer to the DPC cutting/WP 
dry remediation cell (Room 1044). 
DTF-WPHSPCD-CC24A 
DTF-WPHSPCD-CC24B 
DTF-WPHSPCD-CC24C 
DTF-WPHSPCD-CC24D 
DTF-WPHSPCD-CC24E 
DTF-WPHSPCD-CC24F 
No defect 
No drop 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-09) Design and operational requirements reduce the drop probability. Design 
and operational requirements specify lift-height limits for unsealed waste packages 
whenever waste packages are transferred. If the limit can not be met, impact absorbers 
are provided. Design and operational requirements limit the probability of exceeding the lift 
height. Canister design requirements and the reliability of fabrication processes limit the 
probability that a DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
25.Drop of a loaded, partially sealed WP (WP with a known weld 
defect) from the WP handling and staging cell overhead crane 
onto a trolley during the transfer from the WP positioning cell 
pedestal and trolley to a trolley for transfer to the DPC cutting/WP 
dry remediation cell (Room 1044). 
DTF-WPHSPCD-CC25A 
DTF-WPHSPCD-CC25B 
DTF-WPHSPCD-CC25C 
DTF-WPHSPCD-CC25D 
DTF-WPHSPCD-CC25E 
DTF-WPHSPCD-CC25F 
No defect 
No drop 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-09) Same disposition as Potential Event DTF-WPHSPCD-CC24. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-73 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
26.Drop or collision of a loaded, partially sealed WP (WP with a 
known weld defect) from the WP handling and staging cell 
overhead crane onto or against a sharp object during transfer 
from the WP positioning cell pedestal and trolley to a trolley for 
transfer to the DPC cutting/WP dry remediation cell (Room 1044). 
DTF-WPHSPCD-CC26 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC6. Preventive Design- 
Procedural 
Safety 
27.Slapdown of a loaded, partially sealed WP (WP with a known weld 
defect) from the WP handling and staging cell overhead crane 
(due to impact with a curb/berm/impact limiter used to maintain 
drop height limits) or trolley edge during the transfer from the WP 
positioning cell pedestal and trolley to a trolley for transfer to the 
DPC cutting/WP dry remediation cell (Room 1044). 
DTF-WPHSPCD-CC27A 
DTF-WPHSPCD-CC27B 
DTF-WPHSPCD-CC27C 
DTF-WPHSPCD-CC27D 
DTF-WPHSPCD-CC27E 
DTF-WPHSPCD-CC27F 
No defect 
No drop 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-09) Same disposition as Potential Event DTF-WPHSPCD-CC24. Preventive Design- 
Procedural 
Safety 
28. Drop of a loaded, sealed WP (WP needing decontamination) from 
the WP handling and staging cell overhead crane onto the floor 
during transfer from the WP survey station to a trolley for transfer 
to the WP/trolley decontamination room (Rooms 1044 and 1094). 
DTF-WPHSPCD-CC28A 
DTF-WPHSPCD-CC28B 
DTF-WPHSPCD-CC28C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Preventive Design- 
Procedural 
Safety 
29. Drop of a loaded, sealed WP (WP needing decontamination) from 
the WP handling and staging cell overhead crane onto a trolley 
during transfer from the WP survey station to a trolley for transfer 
to the WP/trolley decontamination room (Room 1044). 
DTF-WPHSPCD-CC29A 
DTF-WPHSPCD-CC29B 
DTF-WPHSPCD-CC29C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Preventive Design- 
Procedural 
Safety 
30.Drop or collision of a loaded, sealed WP (WP needing 
decontamination) from the WP handling and staging cell overhead 
crane onto or against a sharp object during transfer from the WP 
survey station to a trolley for transfer to the WP/trolley 
decontamination room (Rooms 1044 and 1094). 
DTF-WPHSPCD-CC30 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC6. Preventive Design- 
Procedural 
Safety 
31.Slapdown of a loaded, sealed WP (WP needing decontamination) 
from the WP handling and staging cell overhead crane (due to 
impact with a curb/berm/impact limiter used to maintain drop 
height limits) or trolley edge during the transfer from the WP 
survey station to a trolley for transfer to the WP/trolley 
decontamination room (Rooms 1044 and 1094). 
DTF-WPHSPCD-CC31A 
DTF-WPHSPCD-CC31B 
DTF-WPHSPCD-CC31C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Additionally, a 
design requirement ensures that waste packages can withstand a tipover during placement 
onto the tilting machine, including contact with trunnion cradles or the floor. 
Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
32. Collision involving the trolley holding the loaded, sealed, 
contaminated or decontaminated WP and the shield doors 
between the WP handling and staging cell and the WP/trolley 
decontamination room (Rooms 1044 and 1094). 
DTF-WPHSPCD-CC32 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-WPHSPCD-CC1. Preventive Design 
33. Shield doors between the WP handling and staging cell and the 
WP/trolley decontamination room close on the trolley holding the 
loaded, sealed, contaminated or decontaminated WP 
(Rooms 1044 and 1094). 
DTF-WPHSPCD-CC33 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC2. Preventive Design 
34. Derailment of a trolley holding the loaded, sealed, contaminated 
or decontaminated WP in the WP/trolley decontamination room 
(or on the rails leading to/from this room) followed by a load 
tipover or fall (Room 1094). 
DTF-WPHSPCD-CC34 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC3. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-74 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
35. Drop or collision of equipment (handling equipment, 
decontamination equipment etc.) onto or against a loaded, sealed 
contaminated or decontaminated WP positioned on a trolley in the 
WP/trolley decontamination room (Room 1094). 
DTF-WPHSPCD-CC35 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC8. Preventive Procedural 
Safety 
36. Drop of a loaded, sealed, decontaminated WP from the WP 
handling and staging cell overhead crane onto the floor during 
transfer from the trolley serving the WP/trolley decontamination 
room to the trolley to the WP loadout cell (Rooms 1044 and 
1094). 
DTF-WPHSPCD-CC36aA 
DTF-WPHSPCD-CC36aB 
DTF-WPHSPCD-CC36aC 
DTF-WPHSPCD-CC36b 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
CC36a (See GET-08 for drop event) Same disposition as Potential Event DTFWPHSPCD-
CC17. 
CC36b (See GET-22 for trolley collision) Same disposition as Potential Event DTFWPHSPCD-
CC1. 
Preventive Design- 
Procedural 
Safety 
37. Drop of a loaded, sealed, decontaminated WP from the WP 
handling and staging cell overhead crane onto a trolley during 
transfer from the trolley serving the WP/trolley decontamination 
room to the trolley to the WP loadout cell. (Rooms 1044 and 
1094). 
DTF-WPHSPCD-CC37A 
DTF-WPHSPCD-CC37B 
DTF-WPHSPCD-CC37C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC17. Preventive Design- 
Procedural 
Safety 
38. Drop or collision of a loaded, sealed, decontaminated WP from 
the WP handling and staging cell overhead crane onto or against 
a sharp object during transfer from the trolley serving the 
WP/trolley decontamination room to the trolley to the WP loadout 
cell (Rooms 1044 and 1094). 
DTF-WPHSPCD-CC38 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC6. Preventive Design- 
Procedural 
Safety 
39. Slapdown (tip-over from an elevated surface) of a loaded, sealed, 
decontaminated WP from the WP handling and staging cell 
overhead crane (due to impact with a curb/berm/impact limiter 
used to maintain drop height limits) or trolley edge during the 
transfer from the trolley serving the WP/trolley decontamination 
room to the trolley to the WP loadout cell (Rooms 1044 and 
1094). 
DTF-WPHSPCD-CC39A 
DTF-WPHSPCD-CC39B 
DTF-WPHSPCD-CC39C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPHSPCD-CC31. Preventive Design- 
Procedural 
Safety 
40. Drop or collision of equipment (handling equipment, etc.) from the 
WP handling and staging cell overhead crane onto or against a 
loaded, sealed or partially sealed (with a known weld defect), 
contaminated or decontaminated WP positioned on a pedestal on 
a trolley, on a trolley without a pedestal, or the WP survey station 
(Room 1044). 
DTF-WPHSPCD-CC40 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC8. Preventive Procedural 
Safety 
41. Derailment of a trolley holding a loaded, sealed WP on the rails 
leading from the WP handling and staging cell to the WP loadout 
cell, followed by a load tipover or fall (Room 1044). 
DTF-WPHSPCD-CC41 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC3. Preventive Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1039, 1040, 1041, 1044, 
2032, 2033, and 2035). 
DTF-WPHSPCD-CCF1 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
2. Flooding due to rupture of water line or clogging of drain 
associated with the high pressure water system used for 
decontamination activities in the WP/trolley decontamination 
room. (Rooms 1039, 1040, 1041, and 1094). 
DTF-WPHSPCD-CCF2 Normal Operations Minor increases in potential worker doses that might be caused by the spread of 
contamination because of flooding would be managed as a normal-operations dose by 
procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-75 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Explosion-Implosion 1. Explosion hazard associated with the WP purging and inerting 
system and the ignition of hydrogen that may have accumulated in 
the WP (Rooms 1039, 1040, 1041, 2032, 2033, and 2035). 
DTF-WPHSPCD-EI1 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventative Procedural 
Safety 
2. WP decontamination system missile due to a fractured 
nozzle/valve stem/pneumatic device (Room 1094). 
DTF-WPHSPCD-EI2 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where the potentially vulnerable 
items may be exposed. 
Preventive Procedural 
Safety 
3. WP inerting system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Rooms 1039, 1040, 1041, 2032, 2033, and 2035). 
DTF-WPHSPCD-EI3 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-EI2. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with handling and other electrically 
powered equipment in the WP handling and staging cell, the WP 
positioning cells, and the WP closure cells, including the cranes 
and the welding subsystem in the WP closure cells (Rooms 1039, 
1040, 1041, 2032, 2033, and 2035). 
DTF-WPHSPCD-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with a trolley holding a loaded WP 
(unsealed or sealed). (Rooms 1039, 1040, 1041, 1044, 1094, 
2032, 2033, and 2035). 
DTF-WPHSPCD-FT2 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-FT1. Preventive Design- 
Procedural 
Safety 
3. Fuel damage by burn-through during welding process/heat 
damage (Rooms 1039, 1040, 1041, 2032, 2033, and 2035). 
DTF-WPHSPCD-FT3 NA Burn-through of the inner lid is not possible with the gas tungsten arc welding process used 
for the closure welds. 
NA NA 
4. Thermal hazard/SNF overheating in a WP during the welding 
process resulting in excessive cladding temperature and possible 
zircaloy cladding (or other cladding) unzipping (Rooms 1039, 
1040, 1041, 2032, 2033, and 2035). 
DTF-WPHSPCD-FT4 NA Overheating of the WP contents due to welding is not possible using the gas tungsten arc 
welding process, which is used for the closure welds. 
NA NA 
5. Thermal hazard/SNF overheating in a partially sealed WP (WP 
with weld defects) in the WP handling and staging cell, prior to 
entering WP remediation (Room 1044). 
DTF-WPHSPCD-FT5 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
6. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses. 
(Rooms 1039, 1040, 1041, 1044, 1094, 2032, 2033, and 2035). 
DTF-WPHSPCD-FT6 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-FT5. Preventive Design 
7. Transient combustible fire in the WP handling and staging cell, 
WP positioning cells, WP closure cells, and the WP/trolley 
decontamination room (Rooms 1039, 1040, 1041, 1044, 1094, 
2032, 2033, and 2035). 
DTF-WPHSPCD-FT7 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-76 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1039, 1040, 1041, 1044, 1094, 2032, 2033, and 2035). 
DTF-WPHSPCD-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Glovebox leak leads radiological release of airborne 
contamination (Room 2024). 
DTF-WPHSPCD-R2 Normal Operations Potential exposure of workers to radiation from a glovebox leak is managed as a normaloperations 
dose by routine procedures that ensure that workers do not receive excessive 
radiation doses. 
Mitigative Procedural 
Safety 
3. Thermal expansion of gases within WP (prior to seal of inner lid) 
leads to radiological release (Rooms 1039, 1040, 1041, 2032, 
2033, and 2035). 
DTF-WPHSPCD-R3 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
4. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1039, 1040, 1041, 1044, 1094, 2032, 
2033, and 2035). 
DTF-WPHSPCD-R4 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations would not cause individuals to be exposed to significant amounts of 
radioactivity. 
Mitigative Procedural 
Safety 
5. Inadvertent opening of a shield door, leading to a worker exposure 
(Rooms 1039, 1040, 1041, 1044, and 1094). 
DTF-WPHSPCD-R5 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
6. Radiation-induced damage to a facility SSC (Rooms 1039, 1040, 
1041, 1044, 1094, 2032, 2033, and 2035). 
DTF-WPHSPCD-R6 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley holding a loaded, sealed or 
unsealed WP derailment followed by a load tipover or fall and a 
rearrangement of the container internals (Rooms 1039, 1040, 
1041, 1044, 1094, 2032, 2033, and 2035). 
DTF-WPHSPCD-F1 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-CC3. Preventive Design 
2. Criticality associated with a drop or slapdown of an loaded, 
unsealed WP and a rearrangement of the container contents 
(including SNF assemblies that may move out of the WP) 
(Rooms 1039, 1040, 1041, 1044, 1094, 2032, 2033, and 2035). 
DTF-WPHSPCD-F2 Beyond Category 2 A design requirement ensures that an unsealed WP that is dropped onto an essentially 
unyielding surface from within its lift-height limits would not spill its contents. A design 
requirement ensures that waste packages are designed to preclude criticality with credit for 
moderator control and without credit for burnup. Demonstration of compliance must 
account for the bowing of fuel rods or other rearrangement of fissile material that may occur 
due to a drop or other handling incident. Design and operational requirements ensure that 
moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
3. Criticality associated with the drop of heavy equipment onto a 
loaded, unsealed WP and a rearrangement of the container 
internals (Rooms 1039, 1040, 1041, 1044, 1094, 2032, 2033, and 
2035). 
DTF-WPHSPCD-F3 Beyond Category 2 Same disposition as Potential Event DTF-WPHSPCD-F2. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-77 April 2005 
Table III-17. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Handling and Staging Cell (Room 1044), Waste Package Positioning Cells (Rooms 1039, 1040 and 1041), Waste Package Closure Cells (Rooms 
2032, 2033 and 2035), and the Waste Package/Trolley Decontamination Room (Room 1094) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
4. Criticality associated with a drop or slapdown of a loaded, sealed 
WP and a rearrangement of the container internals (Rooms 1039, 
1040, 1041, 1044, 1094, 2032, 2033, and 2035). 
DTF-WPHSPCD-F4 Beyond Category 2 A design requirement ensures that sealed waste packages are designed such that drops, 
collisions, and other handling impacts within their design bases, allowing for rearrangement 
of the waste package internals and without credit for burnup cannot lead to a 
nuclear criticality. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; CHF = Canister Handling Facility; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; NA = 
not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart; WPHSPCD = waste package handling and staging, positioning, closure and decontamination. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example WPHSPCD, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
Additional room(s) with potential events in this table: Room 1036  Entrance Vestibule. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-78 April 2005 
Table III-18. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Loadout Cell (Room 1088), Waste Package Transporter Vestibule (Room 1087), and Exit Vestibule (Room 1086) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the trolley holding the loaded, sealed WP and 
the shield doors between the WP handling and staging cell and 
the WP loadout cell (Room 1088). 
DTF-WPLCTEV-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. Shield doors between the WP handling and staging cell and the 
WP loadout cell close on the trolley holding the loaded, sealed 
WP (Room 1088). 
DTF-WPLCTEV-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of a trolley in the WP loadout cell holding a loaded, 
sealed WP followed by a load tipover or fall (Room 1088). 
DTF-WPLCTEV-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
4. Drop of a loaded, sealed WP from the WP loadout cell overhead 
crane onto the floor during the transfer from the trolley to the 
tilting machine (Room 1088). 
DTF-WPLCTEV-CC4A 
DTF-WPLCTEV-CC4B 
DTF-WPLCTEV-CC4C 
No Drop 
No Breach 
Beyond Category 2 
(See GET-08) Design and operational requirements reduce the drop probability. 
Design and operational requirements limit the lift height of waste packages in horizontal 
and vertical orientations. Design requirements ensure that waste packages withstand 
without breaching drops and tipovers within their lift height limits. Design and operational 
requirement limits the probability of exceeding the lift height. 
Preventive Design- 
Procedural 
Safety 
5. Drop of a loaded, sealed WP from the WP loadout cell overhead 
crane back onto the trolley during the transfer from the trolley to 
the tilting machine (Room 1088). 
DTF-WPLCTEV-CC5A 
DTF-WPLCTEV-CC5B 
DTF-WPLCTEV-CC5C 
No Drop 
No Breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPLCTEV-CC4. Preventive Design- 
Procedural 
Safety 
6. Drop or collision of a loaded, sealed WP from the WP loadout cell 
overhead crane onto or against a sharp object (including the tilting 
machine) during transfer from the trolley to the tilting machine 
(Room 1088). 
DTF-WPLCTEV-CC6 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
7. Slapdown (either forward into the WP turntable or backward onto 
the floor) of a loaded, sealed WP engaged in the tilting machine 
from the WP loadout cell overhead crane during the lowering of 
the WP to the horizontal position on the WP pallet previously 
placed on the WP turntable (Room 1088). 
DTF-WPLCTEV-CC7A 
DTF-WPLCTEV-CC7B 
DTF-WPLCTEV-CC7C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPLCTEV-CC4. Additionally, a 
design requirement ensures that waste packages can withstand a tipover during placement 
onto the tilting machine, including contact with trunnion cradles or the floor and a design 
requirement prevents backward slapdowns associated with the tilting machine for waste 
packages. 
Preventive Design- 
Procedural 
Safety 
8. Collision of the tilting machine against a loaded, sealed WP on a 
pallet on the WP turntable (Room 1088). 
DTF-WPLCTEV-CC8 Beyond Category 2 A design or operational requirement ensures that an impact or collision between the 
trunnion collar removal machine, WP turntable, or WP tilting machine and a WP will not 
breach the WP or cause it to fall off the emplacement pallet. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-79 April 2005 
Table III-18. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Loadout Cell (Room 1088), Waste Package Transporter Vestibule (Room 1087), Exit Vestibule (Room 1086) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Equipment drop or collision (including lifting yokes) onto or against 
a loaded, sealed WP during the process to move the WP from the 
trolley to the tilting machine (Room 1088). 
DTF-WPLCTEV-CC9 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety 
10.Collision of the WP trunnion collar removal machine and the WP 
during trunnion collar removal (Room 1088). 
DTF-WPLCTEV-CC10 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC8. Preventive Design- 
Procedural 
Safety 
11.Drop of trunnion collar from the 100-ton overhead bridge crane in 
the WP loadout cell onto a WP during trunnion collar removal 
(Room 1088). 
DTF-WPLCTEV-CC11 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC9. Preventive Procedural 
Safety 
12.Movement of the WP turntable holding the loaded, sealed WP 
(positioned on the WP pallet) prior to disengagement/removal of 
the WP trunnion collar removal machine (Room 1088). 
DTF-WPLCTEV-CC12 Beyond Category 2 A design requirement precludes premature actuation of the turntable, holding the waste 
package on an emplacement pallet, before the disengagement of the trunnion collar 
removal machine. 
Preventive Design 
13.Collision of the WP transporter or transporter bedplate with the 
loaded, sealed WP positioned on a pallet on the WP turntable 
during movement of the bedplate under the WP turntable 
(Room 1088). 
DTF-WPLCTEV-CC13 Beyond Category 2 Design and operational requirements ensure that the waste package transporter and 
its bedplate do not collide with a waste package on the turntable and cause a waste 
package breach. 
Preventive Design- 
Procedural 
Safety 
14.Drop of the loaded, sealed WP (positioned on a pallet) onto the 
transporter bedplate during the lowering of the WP and 
emplacement pallet from the WP turntable to the transporter 
bedplate positioned under the WP turntable (Room 1088). 
DTF-WPLCTEV-CC14A 
DTF-WPLCTEV-CC14B 
DTF-WPLCTEV-CC14C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event DTF-WPLCTEV-CC4. Preventive Design- 
Procedural 
Safety 
15.Collision involving a WP transporter (holding the sealed WP on a 
pallet) and the shield doors between the WP loadout cell and the 
WP transporter vestibule (Rooms 1087 and 1088). 
DTF-WPLCTEV-CC15 Beyond Category 2 A design requirement ensures that the WP transporter transports the WP in a manner such 
that if a collision or derailment (excluding tipover) occurs, the WP impact energy would be 
low enough to preclude a WP breach. A design requirement ensures that the WP 
transporter transports the WP in a manner such that if a collision or derailment leading to a 
transporter tipover occurs, the WP impact energy would be low enough to preclude a WP 
breach. 
Preventive Design 
16.Shield doors between the WP loadout cell and the WP transporter 
vestibule close on the WP transporter (holding the loaded, sealed 
WP on a pallet) (Rooms 1087 and 1088). 
DTF-WPLCTEV-CC16 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC2. Preventive Design 
17.Collision involving WP transporter (holding the loaded, sealed WP 
on a pallet) and the shield doors between the WP transporter 
vestibule and the exit vestibule (Rooms 1086 and 1087). 
DTF-WPLCTEV-CC17 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC15. Preventive Design 
18.Shield doors between the WP transporter vestibule and the exit 
vestibule close on the WP transporter (holding the loaded, sealed 
WP on a pallet) (Rooms 1086 and 1087). 
DTF-WPLCTEV-CC18 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC2. Preventive Design 
19.Collision involving the WP transporter (holding the loaded, sealed 
WP on a pallet) and the doors between the exit vestibule and the 
ambient air (outside) (Room 1086). 
DTF-WPLCTEV-CC19 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC15. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-80 April 2005 
Table III-18. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Loadout Cell (Room 1088), Waste Package Transporter Vestibule (Room 1087), Exit Vestibule (Room 1086) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
20.Doors between the exit vestibule and the ambient air (outside) 
close on the WP transporter (holding the loaded, sealed WP on a 
pallet). (Room 1086). 
DTF-WPLCTEV-CC20 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC2. Preventive Design 
21.Derailment of a WP transporter in the exit vestibule, WP 
transporter vestibule, or WP loadout cell followed by a load 
tipover or fall (Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-CC21 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-CC15. Preventive Design 
22.Drop of a heavy load from the waste package loadout crane 
auxiliary trolley hoist in the WP loadout crane park cell onto a 
loaded, sealed WP (Room 1088). 
DTF-WPLCTEV-CC22 Beyond Category 2 An operational requirement ensures that heavy loads that could potentially initiate an 
event sequence if dropped on a transportation cask, transfer cask or waste package can 
not be lifted over or near a transportation cask, transfer cask, or waste package, except as 
needed for transfer and closure operations. 
Preventive Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-FCC1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed waste package, therefore this event does not occur 
unless an event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a 
possible outcome of any event that exposes SNF to air. Consequence analyses account 
for the possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Hydraulic system or other pneumatic or pressurized system 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the WP loadout cell, the WP 
transporter vestibule, or the exit vestibule (including the WP 
trunnion collar removal machine, the tilting machine, and the WP 
turntable). (Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with a trolley holding a sealed WP 
(Rooms 1087 and 1088). 
DTF-WPLCTEV-FT2 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-FT1. Preventive Design- 
Procedural 
Safety 
3. Electrical fire associated with the WP loadout cell overhead bridge 
crane (Room 1088). 
DTF-WPLCTEV-FT3 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-FT1. Preventive Design- 
Procedural 
Safety 
4. Electrical fire associated with equipment on the WP transporter, 
including motors to extend the WP transporter bedplate 
(Rooms 1086 and 1087). 
DTF-WPLCTEV-FT4 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-FT1. Preventive Design- 
Procedural 
Safety 
5. Electrical fire associated with the WP transport locomotive 
(Rooms 1086 and 1087). 
DTF-WPLCTEV-FT5 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-81 April 2005 
Table III-18. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Loadout Cell (Room 1088), Waste Package Transporter Vestibule (Room 1087), Exit Vestibule (Room 1086) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
6. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
(Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-FT6 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
7. Transient combustible fire in the WP loadout cell, the WP 
transporter vestibule, or the exit vestibule (Rooms 1086, 1087, 
and 1088). 
DTF-WPLCTEV-FT7 Beyond Category 2 Same disposition as Potential Event DTF-WPLCTEV-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Inadvertent opening of a shield door, leading to a worker exposure 
(Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-R3 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
4. Inadvertent opening of the WP transporter shielded enclosure 
doors, leading to a worker exposure (Rooms 1086, 1087, and 
1088). 
DTF-WPLCTEV-R4 Beyond Category 2 Same disposition as Potential Event CHF-WPL-R3. Preventive Design- 
Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1086, 1087, 
and 1088). 
DTF-WPLCTEV-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley holding a loaded, sealed WP 
derailment followed by a load tipover or fall and a rearrangement 
of the container internals (Room 1088). 
DTF-WPLCTEV-F1 Beyond Category 2 Same disposition as Potential Event CHF-WPL-F2. Additionally, a design requirement 
ensures that loaded transfer trolleys do not derail or drop their loads. Design requirements 
apply to trolleys for casks, waste packages, site-specific casks, and dual-purpose 
canisters. 
Preventive Design 
2. Criticality associated with a drop, slapdown, or collision of a 
loaded, sealed WP and a rearrangement of the container internals 
(Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-F2 Beyond Category 2 A design requirement ensures that sealed waste packages are designed such that drops, 
collisions, and other handling impacts within their design bases (allowing for 
rearrangement of the waste package internals and without credit for burnup) cannot lead to 
a nuclear criticality. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-82 April 2005 
Table III-18. Disposition of Internal Events That Occur Inside the Dry Transfer Facility: Waste Package Loadout Cell (Room 1088), Waste Package Transporter Vestibule (Room 1087), Exit Vestibule (Room 1086) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive or 
Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Criticality associated with a WP transporter derailment followed by 
a load tipover or fall and rearrangement of the WP internals 
(Rooms 1086, 1087, and 1088). 
DTF-WPLCTEV-F3 Beyond Category 2 Same disposition as Potential Events DTF-WPLCTEV-CC15 and DTF-WPLCTEV-F2. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; CHF = Canister Handling Facility; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; NA 
= not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart; WPLCTEV = waste package loadout cell transport exit vestibule. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example WPLCTEV, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-83 April 2005 
Table III-19. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Waste Package Remediation): Dual-purpose Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the trolley holding a loaded, partially sealed WP 
(WP with a known weld defect) and the shield doors between the 
WP handling and staging cell and the WP/trolley decontamination 
room or the doors between the WP/trolley decontamination room 
and the DPC cutting/WP dry remediation cell. (Room 1097). 
DTF-DPCWPDRM-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit could not cause the trolley to drop its load. 
Preventive Design 
2. Shield doors between the WP handling and staging cell and the 
WP/trolley decontamination room or the doors between the 
WP/trolley decontamination room and the DPC cutting/WP dry 
remediation cell close on the trolley holding a loaded, partially 
sealed WP (WP with a known weld defect) (Room 1097). 
DTF-DPCWPDRM-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of a trolley holding a loaded, partially sealed WP (WP 
with a known weld defect) followed by a load tipover or fall in the 
DPC cutting/WP dry remediation cell (Room 1097). 
DTF-DPCWPDRM-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
4. Drop of a loaded, partially sealed WP (WP with a known weld 
defect) from the DPC cutting/WP dry remediation cell overhead 
crane onto the floor during the transfer from the trolley to the 
cutting machine base (Room 1097). 
DTF-DPCWPDRM-CC4A 
DTF-DPCWPDRM-CC4B 
DTF-DPCWPDRM-CC4C 
DTF-DPCWPDRM-CC4D 
DTF-DPCWPDRM-CC4E 
DTF-DPCWPDRM-CC4F 
No Defect 
No Drop 
Category 2 
No Breach 
Beyond Category 2 
Beyond Category 2 
(See GET-09) Design and operational requirements reduce the drop probability. Design 
and operational requirements specify lift-height limits for unsealed waste packages 
whenever waste packages are transferred. If the limit can not be met, impact absorbers 
are provided. Design and operational requirements limit the probability of exceeding the lift 
height. Canister design requirements and the reliability of fabrication processes limit the 
probability that a DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
5. Drop of a loaded, partially sealed WP (WP with a known weld 
defect) from the DPC cutting/WP dry remediation cell overhead 
crane onto the cutting machine base during the transfer from the 
trolley to the cutting machine base (Room 1097). 
DTF-DPCWPDRM-CC5A 
DTF-DPCWPDRM-CC5B 
DTF-DPCWPDRM-CC5C 
DTF-DPCWPDRM-CC5D 
DTF-DPCWPDRM-CC5E 
DTF-DPCWPDRM-CC5F 
No Defect 
No Drop 
Category 2 
No Breach 
Beyond Category 2 
Beyond Category 2 
(See GET-09) Same disposition as Potential Event DTF-DPCWPDRM-CC4. Preventive Design- 
Procedural 
Safety 
6. Drop or collision of a loaded, partially sealed WP (WP with a known 
weld defect) from the DPC cutting/WP dry remediation cell 
overhead crane onto or against a sharp object during transfer from 
the trolley to the cutting machine base. (Room 1097). 
DTF-DPCWPDRM-CC6 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
7. Drop or collision of equipment (including a lifting yoke) from the 
DPC cutting/WP dry remediation cell overhead crane onto or 
against a loaded, partially sealed WP (WP with a known weld 
defect). (Room 1097). 
DTF-DPCWPDRM-CC7 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-84 April 2005 
Table III-19. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Waste Package Remediation): Dual-purpose Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Drop or collision of the WP/canister cutting machine onto or against 
the defective WP during the lowering of the machine for the lidcutting 
operation (Room 1097). 
DTF-DPCWPDRM-CC8 Beyond Category 2 A design requirement ensures that the lid-cutting machine is designed to preclude a 
radiological release due to damage inflicted upon the WP contents during the lid-cutting 
process. 
Preventive Design 
9. Damage to the WP contents (fuel assembly[ies], canisters, etc.) 
during lid-cutting operations (Room 1097). 
DTF-DPCWPDRM-CC9 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-CC8. Preventive Design 
10.Drop or collision of the WP/canister cutting machine onto or against 
the defective WP during the removal of the machine after the lidcutting 
operation (Room 1097). 
DTF-DPCWPDRM-CC10 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-CC8. Preventive Design 
11.Drop of a severed lid (outer, middle, or inner) back onto the WP 
from an overhead crane during, or after, the completion of the WP 
cutting (Room 1097). 
DTF-DPCWPDRM-CC11A 
DTF-DPCWPDRM-CC11B 
DTF-DPCWPDRM-CC11C 
DTF-DPCWPDRM-CC11D 
DTF-DPCWPDRM-CC11E 
DTF-DPCWPDRM-CC11F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
12.Drop or collision of handling equipment (lid grapple) onto or against 
the unsealed (open), loaded WP (Room 1097). 
DTF-DPCWPDRM-CC12a 
DTF-DPCWPDRM-CC12bA 
DTF-DPCWPDRM-CC12bB 
DTF-DPCWPDRM-CC12bC 
DTF-DPCWPDRM-CC12bD 
DTF-DPCWPDRM-CC12bE 
DTF-DPCWPDRM-CC12bF 
Beyond Category 2 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
An operational requirement prohibits suspending a lid grapple above the open waste 
package or DPC unless the lid is in place or is being lifted. 
CC12a. If the lid is in place, same disposition as Potential Event DTF-DPCWPDRM-CC7. 
CC12b. If the lid is being lifted, the potential event is analyzed as a lid-drop event 
(Bounded by GET-02) Same disposition as Potential Event DTF-DPCWPDRMCC11. 
Preventive Design- 
Procedural 
Safety 
13.Drop of an unsealed (open), loaded WP from the overhead crane in 
the DPC cutting/WP dry remediation cell onto the floor during the 
transfer of the WP from the cutting machine base to the trolley that 
travels to the unloading port to the waste transfer cell (Room 1097). 
DTF-DPCWPDRM-CC13A 
DTF-DPCWPDRM-CC13B 
DTF-DPCWPDRM-CC13C 
DTF-DPCWPDRM-CC13D 
DTF-DPCWPDRM-CC13E 
No drop 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Design and operational requirements reduce the drop probability. Design 
and operational requirements specify lift-height limits for unsealed waste packages 
whenever waste packages are transferred. If the limit can not be met, impact absorbers 
are provided. Design and operational requirements limit the probability of exceeding the liftheight 
limit. Canister design requirements and the reliability of fabrication processes limit 
the probability that a DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
14.Drop of an unsealed (open), loaded WP from the overhead crane in 
the DPC cutting/WP dry remediation cell onto the trolley during the 
transfer of the WP from the cutting machine base to the trolley that 
travels to the unloading port to the waste transfer cell (Room 1097). 
DTF-DPCWPDRM-CC14A 
DTF-DPCWPDRM-CC14B 
DTF-DPCWPDRM-CC14C 
DTF-DPCWPDRM-CC14D 
DTF-DPCWPDRM-CC14E 
No drop 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event DTF-DPCWPDRM-CC13. Preventive Design- 
Procedural 
Safety 
15.Drop or collision of an unsealed (open), loaded WP from the 
overhead crane in the DPC cutting/WP dry remediation cell onto or 
against a sharp object during transfer of the WP from the cutting 
machine base to the trolley that travels to the unloading port to the 
waste transfer cell (Room 1097). 
DTF-DPCWPDRM-CC15 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-CC6. Preventive Design- 
Procedural 
Safety 
16.Slapdown of an unsealed (open), loaded WP following a drop from 
the overhead crane in the DPC cutting/WP dry remediation cell 
onto the edge of a pedestal or impact limiter on/near the trolley that 
travels to the unloading port to the waste transfer cell during the lift 
and transfer to the trolley (Room 1097). 
DTF-DPCWPDRM-CC16A 
DTF-DPCWPDRM-CC16B 
DTF-DPCWPDRM-CC16C 
DTF-DPCWPDRM-CC16D 
DTF-DPCWPDRM-CC16E 
No drop 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event DTF-DPCWPDRM-CC13. Additionally, 
a design requirement ensures that an unsealed WP that is dropped onto an essentially 
unyielding surface from within its lift-height limits would not spill its contents. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-85 April 2005 
Table III-19. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Waste Package Remediation): Dual-purpose Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
17.Derailment of a trolley (that travels to the unloading port to the 
waste transfer cell) holding a loaded WP (in an opened state) in the 
DPC cutting/WP dry remediation cell followed by a load tipover or 
fall (Room 1097). 
DTF-DPCWPDRM-CC17 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-CC3. Preventive Design 
18.Drop or collision of an SNF assembly from the spent fuel transfer 
machine into or against the WP (Room 1097). 
DTF-DPCWPDRM-CC18A 
DTF-DPCWPDRM-CC18B 
DTF-DPCWPDRM-CC18C 
No drop 
Category 2 
Category 2 
(See GET-10) Design and operational requirements for commercial SNF handling 
equipment reduce the drop rate and collision probabilities for commercial SNF assembly 
transfers, including those in single-assembly canisters. 
Preventive Design- 
Procedural 
Safety 
19.Drop or collision of an SNF assembly from the spent fuel transfer 
machine onto or against another SNF assembly or assemblies in 
the WP (Room 1097). 
DTF-DPCWPDRM-CC19A 
DTF-DPCWPDRM-CC19B 
DTF-DPCWPDRM-CC19C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DPCWPDRM-CC18. Preventive Design- 
Procedural 
Safety 
20.Impact due to horizontal movement of an SNF assembly by the 
spent fuel transfer machine before the assembly is fully lifted out of 
the WP (Room 1097). 
DTF-DPCWPDRM-CC20A 
DTF-DPCWPDRM-CC20B 
DTF-DPCWPDRM-CC20C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DPCWPDRM-CC18. Preventive Design- 
Procedural 
Safety 
21.Drop and slapdown of an SNF assembly from the spent fuel 
transfer machine (due to impact with an edge of the WP, floor 
edge, WP internal baffle, etc.) during the transfer of the SNF 
assemblies to a WP or staging rack (Room 1097). 
DTF-DPCWPDRM-CC21A 
DTF-DPCWPDRM-CC21B 
DTF-DPCWPDRM-CC21C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DPCWPDRM-CC18. Preventive Design- 
Procedural 
Safety 
22.Drop or collision of a naval SNF canister, a DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO from the 
waste transfer cell overhead crane back into or against the WP 
being unloaded (Room 1097). 
DTF-DPCWPDRM-CC22A 
DTF-DPCWPDRM-CC22B 
DTF-DPCWPDRM-CC22C 
DTF-DPCWPDRM-CC22D 
DTF-DPCWPDRM-CC22E 
DTF-DPCWPDRM-CC22F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Design and operational requirements reduce the drop probability. A design 
requirement limits lift heights for DOE SNF canisters, DOE HLW canisters, and DOE SNF 
multicanister overpacks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. Design requirements ensures that standardized DOE SNF canisters would 
withstand without breach a drop of another standardized DOE SNF canister and that MCOs 
would withstand without breach a drop of another MCO dropped from within its lift-height 
limits. Dropping a DOE SNF canister on a DOE HLW canister is rendered beyond Category 
2 by an operational requirement to not transfer or remove the DOE SNF canister into or 
from the waste package or site-specific cask if there are one or more DOE HLW canisters 
present in the waste package or site-specific cask. For collisions, a design requirement 
limits speed for crane transfers such that a collision at the maximum speed could not 
breach an MSC, transportation cask, transfer cask, DPC, DOE or naval canister, or waste 
package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
23.Impact due to horizontal movement of a naval SNF canister, a DOE 
HLW canister, a [standardized] DOE SNF canister, or a DOE SNF 
MCO with the waste transfer cell overhead crane before the 
canister is completely removed from the (Room 1097). 
DTF-DPCWPDRM-CC23 Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force to 
breach a transportation cask, MSC, waste package, or canister as the result of attempts to 
overcome mechanical constraints. 
Preventive Design 
24.Drop or collision of a DOE HLW canister from the waste transfer 
cell crane back onto or against, another DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO in a WP 
(Room 1097). 
DTF-DPCWPDRM-CC24A 
DTF-DPCWPDRM-CC24B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
25.Drop or collision of a [standardized] DOE SNF canister from the 
waste transfer cell crane onto or against, a DOE HLW canister in 
the WP (Room 1097). 
DTF-DPCWPDRM-CC25 Beyond Category 2 Dropping a DOE SNF canister on a DOE HLW canister is rendered beyond Category 2 by 
an operational requirement to not transfer or remove the DOE SNF canister into or from the 
waste package or site-specific cask if there are one or more DOE HLW canisters present in 
the waste package or site-specific cask. For collisions, a design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-86 April 2005 
Table III-19. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Waste Package Remediation): Dual-purpose Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
26.Drop or collision of a DOE SNF MCO from the waste transfer cell 
crane onto or against, another DOE SNF MCO or a DOE HLW 
canister in the WP (Room 1097). 
DTF-DPCWPDRM-CC26 Beyond Category 2 Same disposition as Potential Event DFT-WPTDRC-CC25. Additionally, a design 
requirement ensures that standardized DOE SNF canisters can withstand without breach a 
drop of another DOE SNF canister dropped from within their lift-height limits. 
Preventive Design- 
Procedural 
Safety 
27.Drop and slapdown of a DOE HLW canister, a DOE SNF MCO, a 
[standardized] DOE SNF canister, or a naval SNF canister from the 
waste transfer cell overhead crane (due to impact with an edge of 
the WP, floor edge, WP internal baffle, etc.) during the transfer 
from the WP to a new WP, MSC, or staging rack (if applicable) 
(Room 1097). 
DTF-DPCWPDRM-CC27A 
DTF-DPCWPDRM-CC27B 
DTF-DPCWPDRM-CC27C 
DTF-DPCWPDRM-CC27D 
DTF-DPCWPDRM-CC27E 
DTF-DPCWPDRM-CC27F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11, Event B for HLW and naval canisters and Event F for DOE SNF and MCO 
canisters) Design and operational requirements reduce the drop probability. A design 
requirement limits lift heights for DOE SNF canisters, DOE HLW canisters, and DOE SNF 
multicanister overpacks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. Design requirements ensures that standardized DOE SNF canisters would 
withstand without breach a drop of another standardized DOE SNF canister and that MCOs 
would withstand without breach a drop of another MCO dropped from within its lift-height 
limits. Operational requirements to not transfer a DOE SNF canister into or from the waste 
package if a DOE HLW canister is present in the same waste package precludes dropping 
a DOE SNF canister on a DOE HLW canister. Additionally, if a DOE SNF or MCO canister, 
that is not defective, is dropped on an edge of a WP, staging-pit or load-port edge, or WP 
internal baffle from the height limits, a design requirement ensures that the canister will not 
breach. 
Preventive Design- 
Procedural 
Safety 
28.Drop or collision of handling equipment into or against an opened 
WP filled with SNF assemblies (Room 1097). 
DTF-DPCWPDRM-CC28A 
DTF-DPCWPDRM-CC28B 
No drop 
Category 2 
(See GET-18) Design and operational requirements reduce the probability of dropping 
handling equipment onto a SNF assembly energetically enough to breach the assembly. A 
design requirement ensures that the spent fuel transfer machine, fuel handling machine 
and other equipment designed to handle individual SNF assemblies are not capable of 
lateral movements of handling equipment at a speed that could initiate an event sequence 
as a result of collision with a SNF assembly. 
Preventive Design- 
Procedural 
Safety 
29.Drop or collision of handling equipment into or against an opened 
WP loaded with a naval SNF canister, DOE HLW canisters, and/or 
[standardized] DOE SNF canisters, and/or DOE SNF MCOs (Room 
1097). 
DTF-DPCWPDRM-CC29A 
DTF-DPCWPDRM-CC29B 
DTF-DPCWPDRM-CC29C 
DTF-DPCWPDRM-CC29D 
DTF-DPCWPDRM-CC29E 
DTF-DPCWPDRM-CC29F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-19) Design and operational requirements reduce the drop probability. An 
operational requirement ensures the establishment of a maximum lift height limit for 
handling equipment suspended above DOE SNF canisters. A design requirement ensures 
that the handling equipment is not capable of causing an event sequence due to a breach 
of a DOE SNF canister if dropped from within the lift-height limit. Design and operational 
requirements limit the probability of exceeding the lift height. Canister design requirements 
and the reliability of fabrication processes limit the probability that a DOE SNF canister or 
DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
Chemical 
Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1097). 
DTF-DPCWPDRM-CCF1 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Explosion hazard associated with the cutting and removal of the 
waste package lid system and the ignition of hydrogen that may 
have accumulated inside the waste package, including hydrogen 
removed during the purging process (Room 1097). 
DTF-DPCWPDRM-EI1 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventative Procedural 
Safety 
2. Cask/waste package purging or sampling system (or other 
pneumatic or pressurized system) missile due to a fractured 
nozzle/valve stem/pneumatic device (Room 1097). 
DTF-DPCWPDRM-EI2 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, 
a transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner 
lid of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-87 April 2005 
Table III-19. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Waste Package Remediation): Dual-purpose Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Fire-Thermal 1. Electrical fire associated with SNF and HLW handling equipment in 
the DPC cutting/WP dry remediation cell (including the overhead 
cranes, manipulators, the chipless cutting equipment, etc.). (Room 
1097). 
DTF-DPCWPDRM-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with the trolley (Room 1097). DTF-DPCWPDRM-FT2 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-FT1. Preventive Design- 
Procedural 
Safety 
3. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive temperature 
and possible zircaloy cladding (or other cladding) unzipping or 
cladding failure due to excessive hoop stresses (Room 1097). 
DTF-DPCWPDRM-FT3 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
4. Thermal hazard (from decay heat) associated with vertical 
orientation of the non-inerted, opened, loaded waste package 
(Room 1097). 
DTF-DPCWPDRM-FT4 Normal Operations Same disposition as Potential Event DTF-DPCWPDRM-CCF1. Mitigative Procedural 
Safety 
5. Transient combustible fire in the DPC cutting/WP dry remediation 
cell (Room 1097). 
DTF-DPCWPDRM-FT5 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1097). 
DTF-DPCWPDRM-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Damage or rupture of the WP sampling and purging system, 
leading to a release of WP internal gases and radioactive material 
(Room 1097). 
DTF-DPCWPDRM-R2 Normal Operations Like the cask-sampling operation, the waste package sampling operation is conducted so 
that exposure of workers to radiation is managed as a normal-operations dose by 
procedures for monitoring radiation doses and assigning work, which ensure that workers 
do not receive excessive radiation doses.. Normal operations releases are expected as a 
result of this potential event. Therefore, no Category 1 or Category 2 event sequences 
occur as a result of this event. 
Mitigative Procedural 
Safety 
3. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1097). 
DTF-DPCWPDRM-R3 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
4. Thermal expansion of gases or other loss of confinement in an 
unsealed cask, leading to radiological release (Room 1097). 
DTF-DPCWPDRM-R4 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Room 1097). DTF-DPCWPDRM-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley (holding a partially sealed WP 
requiring remediation) derailment followed by a load tipover or fall 
and a rearrangement of the container internals (Room 1097). 
DTF-DPCWPDRM-F1 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-CC3. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-88 April 2005 
Table III-19. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Waste Package Remediation): Dual-purpose Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Criticality associated with a drop of an SNF assembly from the 
waste transfer cell spent fuel transfer machine back into the WP 
being unloaded and a rearrangement of the WP internals (Room 
1097). 
DTF-DPCWPDRM-F2 Beyond Category 2 A design requirement ensures that waste packages are designed to preclude criticality with 
credit for moderator control and without credit for burnup. Demonstration of compliance 
must account for the bowing of fuel rods or other rearrangement of fissile material that may 
occur due to a drop or other handling incident. Design and operational requirements 
ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
3. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine back into a WP being unloaded and a 
rearrangement of the fuel rods that comprise the assembly due to 
impact (Room 1097). 
DTF-DPCWPDRM-F3 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-F2. Preventive Design- 
Procedural 
Safety 
4. Criticality associated with a drop or slapdown of a WP from the 
DPC cutting/WP dry remediation cell overhead crane and a 
rearrangement of the container internals (Room 1097). 
DTF-DPCWPDRM-F4 Beyond Category 2 A design requirement ensures that sealed waste packages are designed such that drops, 
collisions, and other handling impacts within their design bases, allowing for rearrangement 
of the waste package internals and without credit for burnup, cannot lead to a nuclear 
criticality. 
Preventive Design 
5. Criticality associated with a drop or slapdown of a naval SNF 
canister, a [standardized] DOE SNF canister, a DOE SNF MCO, or 
a DOE HLW canister from the waste transfer cell overhead crane 
during WP unloading (Room 1097). 
DTF-DPCWPDRM-F5 Beyond Category 2 Design requirements ensure that a drop of a DOE SNF canister does not lead to a nuclear 
criticality with the most reactive configuration of DOE SNF canisters and moderator control. 
Design and operational requirements ensure that moderator control is in effect. There is no 
potential for criticality of DOE HLW canisters. Criticality of a naval canister following a drop, 
or other impact event, has been evaluated to be Beyond Category 2 based upon 
probabilities of independent events required for criticality. 
Preventive Design- 
Procedural 
Safety 
6. Criticality associated with a trolley (holding an unsealed, open WP) 
derailment followed by a load tipover or fall and a rearrangement of 
the container internals (Room 1097). 
DTF-DPCWPDRM-F6 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-F1. Preventive Design 
7. Criticality associated with the drop of heavy equipment onto an 
unsealed, open WP and a rearrangement of the container internals 
(Room 1097). 
DTF-DPCWPDRM-F7 Beyond Category 2 Same disposition as Potential Event DTF-DPCWPDRM-F4. Additionally, a design 
requirement ensures that waste packages must demonstrate criticality safety with 
moderator control and must account for the bowing of fuel rods or other rearrangement of 
fissile material that may occur due to a drop or other handling incident. Design and 
operational requirements ensure that moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; CHF = Canister Handling Facility; DBGM = design basis ground motion; DPCWPDRM = dual-purpose canister waste package dry remediation; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosionimplosion; 
F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example DPCWPDRM, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-89 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste 
Package Dry Remediation Cell (Room 1097) 
Disposition of Event 
Generic Event 
Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision- 
Crushing 
1. Collision involving the trolley holding the cask or MSC requiring 
remediation and the shield doors between the cask and MSC 
docking room and the cask/MSC turntable room, the cask/MSC 
turntable room and the cask preparation room, the cask 
preparation room and the DPC preparation/cask dry remediation 
room, the DPC preparation/cask dry remediation room and the 
DPC docking room, the DPC docking room and the cask 
docking/dry remediation room, or the cask docking/dry 
remediation room and the tool spare transfer room (Rooms 1069, 
1073, 1074, 1100, 1101, 1109, and 1127). 
DTF-DRMCDTDPC-CC1DTF- Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. Shield doors between the cask and MSC docking room and the 
cask/MSC turntable room, the cask/MSC turntable room and the 
cask preparation room, the cask preparation room and the DPC 
preparation/cask dry remediation room, the DPC preparation/cask 
dry remediation room and the DPC docking room, the DPC 
docking room and the cask docking/dry remediation room, or the 
cask docking/dry remediation room and the tool spare transfer 
room close on the trolley holding the cask or MSC requiring 
remediation (Rooms 1069, 1073, 1074, 1100, 1101, 1109, and 
1127). 
DTF-DRMCDTDPC-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of a trolley in the cask and MSC docking room, the 
cask/MSC turntable room, the cask preparation room, the DPC 
preparation/cask dry remediation room, the DPC docking room, 
the cask docking/dry remediation room, or the tool spare transfer 
room while holding a cask or MSC, followed by a load tipover or 
fall (Rooms 1069, 1073, 1074, 1100, 1101, 1109, and 1127). 
DTF-DRMCDTDPC-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
4. Drop or collision of tools or equipment onto or against a cask or 
MSC requiring remediation (Rooms 1069, 1073, 1074, 1100, 
1101, 1109, and 1127). 
DTF-DRMCDTDPC-CC4 Beyond Category 2 Operational requirement ensures that the handling equipment associated with cask 
handling and preparation is not capable of breaching a transportation cask, with or without 
impact limiters, or a site-specific cask if collided against the cask or dropped onto the cask 
from within the lift-height limit. 
Preventive Procedural 
Safety 
5. Collision involving an access platform or a mobile elevated 
platform (if required) and a cask or MSC requiring remediation 
(Rooms 1109 and 1127). 
DTF-DRMCDTDPC-CC5 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, mobile 
elevated platforms, and forklifts operated in the facility are not operated in a manner that 
could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
6. Collision of a trolley holding the cask or MSC requiring 
remediation with another trolley holding a cask or MSC on the 
turntable in the DPC docking room or on the tracks leading to the 
cask docking/dry remediation room or tool spare transfer room 
(Rooms 1101, 1109, and 1127). 
DTF-DRMCDTDPC-CC6 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-DRMCDTDPC-CC1. Preventive Design 
7. Drop or collision of a docking port (mobile slab) onto or against a 
cask or MSC (Rooms 1069 and 1109). 
DTF-DRMCDTDPC-CC7 Beyond Category 2 A design requirement ensures that a drop of or collision involving components associated 
with a docking port will not breach the lid of a cask or MSC situated at the docking port. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-90 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Drop or collision of a docking port plug onto or against a cask lid 
or MSC lid (with outer lid removed [if applicable] and inner lid 
unbolted but in place) (Rooms 1069 and 1109). 
DTF-DRMCDTDPC-CC8 Beyond Category 2 Design requirements ensure that portions of a non-ITS SSC which, upon failure, could 
adversely interact with an ITS SSC and prevent its safety function from being performed 
are classified as ITS, redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC, or, for seismic interactions, designed to the same seismic DBGM as 
the ITS SSCs subjected to the potential unacceptable interaction. 
Preventive Design 
9. Drop of an inner lid on a cask or MSC (with outer lid removed [if 
applicable]) (Rooms 1069 and 1109). 
DTF-DRMCDTDPC-CC9A 
DTF-DRMCDTDPC-CC9B 
DTF-DRMCDTDPC-CC9C 
DTF-DRMCDTDPC-CC9D 
DTF-DRMCDTDPC-CC9E 
DTF-DRMCDTDPC-CC9F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
10.Drop or collision of a grapple or other handling equipment into or 
against an open cask or MSC loaded with commercial SNF 
assemblies, a DPC, a DOE HLW canister, a DOE SNF MCO, or a 
[standardized] DOE SNF canister (Rooms 1069 and 1109). 
DTF-DRMCDTDPC -CC10aA 
DTF-DRMCDTDPC -CC10aB 
DTF-DRMCDTDPC -CC10bA 
DTF-DRMCDTDPC -CC10bB 
DTF-DRMCDTDPC -CC10bC 
DTF-DRMCDTDPC -CC10bD 
DTF-DRMCDTDPC -CC10bE 
DTF-DRMCDTDPC -CC10bF 
No drop 
Category 2 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
CC10a. (See GET-18 for commercial SNF) Design and operational requirements reduce 
the probability of dropping handling equipment onto a SNF assembly energetically 
enough to breach the assembly. A design requirement ensures that the spent fuel 
transfer machine, fuel handling machine and other equipment designed to handle 
individual SNF assemblies are not capable of lateral movements of handling 
equipment at a speed that could initiate an event sequence as a result of collision 
with a SNF assembly. 
CC10b. (See GET-19 for non-commercial SNF) Design and operational requirements 
reduce the drop probability. An operational requirement ensures the establishment 
of a maximum lift height limit for handling equipment suspended above DOE SNF 
canisters. A design requirement ensures that the handling equipment is not 
capable of causing an event sequence due to a breach of a DOE SNF canister if 
dropped from within the lift-height limit. Design and operational requirements limit 
the probability of exceeding the lift height. Canister design requirements and the 
reliability of fabrication processes limit the probability that a DOE SNF canister or 
DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
11.Drop or collision of an SNF assembly from the DPC cutting/WP 
dry remediation cell crane back into or against a cask or MSC 
being unloaded (Room 1109). 
DTF-DRMCDTDPC-CC11A 
DTF-DRMCDTDPC-CC11B 
DTF-DRMCDTDPC-CC11C 
No drop 
Category 2 
Category 2 
(See GET-10) Design and operational requirements for commercial SNF handling 
equipment reduce the drop rate and collision probabilities for commercial SNF assembly 
transfers, including those in single-assembly canisters. 
Preventive Design- 
Procedural 
Safety 
12.Drop or collision of an SNF assembly from the DPC cutting/WP 
dry remediation cell crane onto or against another SNF assembly 
in a cask or MSC (Room 1109). 
DTF-DRMCDTDPC-CC12A 
DTF-DRMCDTDPC-CC12B 
DTF-DRMCDTDPC-CC12C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
13.Impact due to horizontal movement of an SNF assembly by the 
DPC cutting/WP dry remediation cell crane before the assembly is 
completely removed from the cask or MSC (Room 1109). 
DTF-DRMCDTDPC-CC13A 
DTF-DRMCDTDPC-CC13B 
DTF-DRMCDTDPC-CC13C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
14.Drop of an SNF assembly from the DPC cutting/WP dry 
remediation cell crane onto the DPC cutting/WP dry remediation 
cell floor (Rooms 1097, 1101, and 1109). 
DTF-DRMCDTDPC-CC14A 
DTF-DRMCDTDPC-CC14B 
DTF-DRMCDTDPC-CC14C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
15. Collision involving an SNF assembly suspended from the DPC 
cutting/WP dry remediation cell crane with equipment located in 
the DPC cutting/WP dry remediation cell or on the cell floor (such 
as lid lifting equipment) (Rooms 1097, 1101, and 1109). 
DTF-DRMCDTDPC-CC15A 
DTF-DRMCDTDPC-CC15B 
DTF-DRMCDTDPC-CC15C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-91 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
16.Drop or collision of an SNF assembly from the DPC cutting/WP 
dry remediation cell crane onto or against a sharp object (Rooms 
1097, 1101, and 1109). 
DTF-DRMCDTDPC-CC16A 
DTF-DRMCDTDPC-CC16B 
DTF-DRMCDTDPC-CC16C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
17.Drop or collision of an SNF assembly from the DPC cutting/WP 
dry remediation cell crane into or against an empty basket located 
on a trolley in the DPC cutting/WP dry remediation cell (Room 
1097). 
DTF-DRMCDTDPC-CC17A 
DTF-DRMCDTDPC-CC17B 
DTF-DRMCDTDPC-CC17C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
18.Drop and slapdown of an SNF assembly from the DPC cutting/WP 
dry remediation cell crane (due to impact with an edge of the 
cask, MSC, basket, floor edge, basket internal baffle, etc.) during 
the transfer from the cask or MSC to a basket on a trolley in the 
DPC cutting/WP dry remediation cell (Rooms 1097, 1101, and 
1109). 
DTF-DRMCDTDPC-CC18A 
DTF-DRMCDTDPC-CC18B 
DTF-DRMCDTDPC-CC18C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
19.Drop or collision of a SNF assembly from the DPC cutting/WP dry 
remediation cell crane onto or against one or more SNF 
assemblies in a basket on a trolley in the DPC cutting/WP dry 
remediation cell (Room 1097). 
DTF-DRMCDTDPC-CC19A 
DTF-DRMCDTDPC-CC19B 
DTF-DRMCDTDPC-CC19C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
20.Drop or collision of a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a DOE SNF MCO from the DPC cutting/WP 
dry remediation cell crane back into or against the cask or MSC 
being unloaded, as applicable (Room 1109). 
DTF-DRMCDTDPC-CC20A 
DTF-DRMCDTDPC-CC20B 
DTF-DRMCDTDPC-CC20C 
DTF-DRMCDTDPC-CC20D 
DTF-DRMCDTDPC-CC20E 
DTF-DRMCDTDPC-CC20F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Design and operational requirements reduce the drop probability. A design 
requirement limits lift heights for DOE SNF canisters, DOE HLW canisters, and DOE SNF 
multicanister overpacks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. Design requirements ensures that standardized DOE SNF canisters would 
withstand without breach a drop of another standardized DOE SNF canister and that MCOs 
would withstand without breach a drop of another MCO dropped from within its lift-height 
limits. Operational requirements to not transfer a DOE SNF canister into or from the waste 
package if a DOE HLW canister is present in the same waste package precludes dropping 
a DOE SNF canister on a DOE HLW canister. For collisions, a design requirement limits 
speed for crane transfers such that a collision at the maximum speed could not breach an 
MSC, transportation cask, transfer cask, DPC, DOE or naval canister, or waste package 
involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
21.Drop or collision of a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a DOE SNF MCO from the DPC cutting/WP 
dry remediation cell crane back onto or against a DPC, a DOE 
HLW canister, a [standardized] DOE SNF canister, or a DOE SNF 
MCO in the cask or MSC, as applicable (Room 1109). 
DTF-DRMCDTDPC-CC21A 
DTF-DRMCDTDPC-CC21B 
DTF-DRMCDTDPC-CC21C 
DTF-DRMCDTDPC-CC21D 
DTF-DRMCDTDPC-CC21E 
DTF-DRMCDTDPC-CC21F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Same disposition as Potential Event DTF-DRMCDTDPC-CC20. Preventive Design- 
Procedural 
Safety 
22.Impact due to horizontal movement of a DPC, a DOE HLW 
canister, a [standardized] DOE SNF canister, or a DOE SNF MCO 
with the DPC cutting/WP dry remediation cell crane before the 
canister is completely removed from the cask or MSC, as 
applicable (Room 1109). 
DTF-DRMCDTDPC-CC22 Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force to 
breach a transportation cask, MSC, waste package, or canister as the result of attempts to 
overcome mechanical constraints. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-92 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
23.Drop and slapdown of a DPC, a DOE HLW canister, a DOE SNF 
MCO, or a [standardized] DOE SNF canister from the DPC 
cutting/WP dry remediation cell crane (due to impact with an edge 
of the cask, MSC, floor edge, basket internal baffle, etc.) during 
the transfer from the cask or MSC (as applicable) to a basket on a 
trolley in the DPC cutting/WP dry remediation cell (Rooms 1097, 
1101, and 1109). 
DTF-DRMCDTDPC-CC23A 
DTF-DRMCDTDPC-CC23B 
DTF-DRMCDTDPC-CC23C 
DTF-DRMCDTDPC-CC23D 
DTF-DRMCDTDPC-CC23E 
DTF-DRMCDTDPC-CC23F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Same disposition as Potential Event DTF-DRMCDTDPC-CC20. Preventive Design- 
Procedural 
Safety 
24.Drop or collision of a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a DOE SNF MCO from the DPC cutting/WP 
dry remediation cell crane onto or against a sharp object (Rooms 
1097, 1101, and 1109). 
DTF-DRMCDTDPC-CC24 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
25. Collision involving a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a DOE SNF MCO suspended from the DPC 
cutting/WP dry remediation cell crane with equipment located in 
the DPC cutting/WP dry remediation cell or on the cell floor 
(Rooms 1097, 1101, and 1109). 
DTF-DRMCDTDPC-CC25 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
26.Drop of a DPC, a DOE HLW canister, a [standardized] DOE SNF 
canister, or a DOE SNF MCO from the DPC cutting/WP dry 
remediation cell crane onto DPC cutting/WP dry remediation cell 
floor (Rooms 1097, 1101, and 1109). 
DTF-DRMCDTDPC-CC26A 
DTF-DRMCDTDPC-CC26B 
DTF-DRMCDTDPC-CC26C 
DTF-DRMCDTDPC-CC26D 
DTF-DRMCDTDPC-CC26E 
DTF-DRMCDTDPC-CC26F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Same disposition as Potential Event DTF-DRMCDTDPC-CC20. Preventive Design- 
Procedural 
Safety 
27.Drop or collision of a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a DOE SNF MCO from the DPC cutting/WP 
dry remediation cell crane into or against an empty basket on a 
trolley in the DPC cutting/WP dry remediation cell (Room 1097). 
DTF-DRMCDTDPC-CC27A 
DTF-DRMCDTDPC-CC27B 
DTF-DRMCDTDPC-CC27C 
DTF-DRMCDTDPC-CC27D 
DTF-DRMCDTDPC-CC27E 
DTF-DRMCDTDPC-CC27F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Same disposition as Potential Event DTF-DRMCDTDPC-CC20. Preventive Design- 
Procedural 
Safety 
28.Drop or collision of a DOE HLW canister from the DPC cutting/WP 
dry remediation cell crane onto or against another DOE HLW 
canister, a [standardized] DOE SNF canister or a DOE SNF MCO 
in a basket, as applicable, on a trolley in the DPC cutting/WP dry 
remediation cell (Room 1097). 
DTF-DRMCDTDPC-CC28A 
DTF-DRMCDTDPC-CC28B 
No drop 
Category 2 
(See GET-11 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
29.Drop or collision of a [standardized] DOE SNF canister from the 
DPC cutting/WP dry remediation cell crane onto or against a DOE 
HLW canister, as applicable, in a basket on a trolley in the DPC 
cutting/WP dry remediation cell (Room 1097). 
DTF-DRMCDTDPC-CC29C 
DTF-DRMCDTDPC-CC29D 
DTF-DRMCDTDPC-CC29E 
DTF-DRMCDTDPC-CC29F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11 Sequences C to F only) Same disposition as Potential Event DTFDRMCDTDPC-
CC20. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-93 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
30.Drop or collision of a DOE SNF MCO from the DPC cutting/WP 
dry remediation cell crane onto or against another DOE SNF MCO 
or a DOE HLW canister, as applicable, in a basket on a trolley in 
the DPC cutting/WP dry remediation cell (Room 1097). 
DTF-DRMCDTDPCCC30C 
DTF-DRMCDTDPCCC30D 
DTF-DRMCDTDPCCC30E 
DTF-DRMCDTDPCCC30F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11 Sequences C to F only) Same disposition as Potential Event DTFDRMCDTDPC-
CC20. 
Preventive Design- 
Procedural 
Safety 
31.Drop or collision of handling equipment from the DPC cutting/WP 
dry remediation cell crane into or against a basket on a trolley in 
the DPC cutting/WP dry remediation cell filled with SNF 
assemblies (Room 1097). 
DTF-DRMCDTDPCCC31A 
DTF-DRMCDTDPCCC31B 
No drop 
Category 2 
(See GET-18) Design and operational requirements reduce the probability of dropping 
handling equipment onto a SNF assembly energetically enough to breach the assembly. A 
design requirement ensures that the spent fuel transfer machine, fuel handling machine 
and other equipment designed to handle individual SNF assemblies are not capable of 
lateral movements of handling equipment at a speed that could initiate an event sequence 
as a result of collision with a SNF assembly. 
Preventive Design- 
Procedural 
Safety 
32.Drop or collision of handling equipment from the DPC cutting/WP 
dry remediation cell crane into or against a basket on a trolley in 
the DPC cutting/WP dry remediation cell loaded with DOE HLW 
canisters, and/or a [standardized] DOE SNF canister, and/or DOE 
SNF MCOs, as applicable (Room 1097). 
DTF-DRMCDTDPC-CC32A 
DTF-DRMCDTDPC-CC32B 
DTF-DRMCDTDPCCC32C 
DTF-DRMCDTDPCCC32D 
DTF-DRMCDTDPCCC32E 
DTF-DRMCDTDPCCC32F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-06) In this potential event, a drop has to occur to cause a collision 
because the equipment would be suspended above the canister. Design and operational 
requirements reduce the drop probability. An operational requirement ensures the 
establishment of a maximum lift height limit for handling equipment suspended above DOE 
SNF canisters. A design requirement ensures that the handling equipment is not capable 
of causing an event sequence due to a breach of a DOE SNF canister if dropped from 
within the lift-height limit. Design and operational requirements limit the probability of 
exceeding the lift height. 
Preventive Design- 
Procedural 
Safety 
33.Drop or collision of handling equipment from the DPC cutting/WP 
dry remediation cell crane into or against a basket on a trolley in 
the DPC cutting/WP dry remediation cell loaded with a DPC (if not 
emptied).(Room 1097). 
DTF-DRMCDTDPC-CC33A 
DTF-DRMCDTDPC-CC33B 
No drop 
Category 2 
(See GET-18) Same disposition as Potential Event DTF-DRMCDTDPC-CC31. Preventive Design- 
Procedural 
Safety 
34.Derailment of a trolley (that travels to the unloading port to the 
waste transfer cell) holding a loaded basket containing SNF 
assemblies in the DPC cutting/WP dry remediation cell, followed 
by a load tipover or fall (Room 1097). 
DTF-DRMCDTDPC-CC34 Beyond category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, 
and dual-purpose canisters. 
Preventive Design 
35.Derailment of a trolley (that travels to the unloading port to the 
waste transfer cell) holding a loaded basket containing a DPC (if 
not emptied), or a combination of DOE HLW canisters, 
[standardized] DOE SNF canisters, or DOE SNF MCOs, as 
applicable, in the DPC cutting/WP dry remediation cell, followed 
by a load tipover or fall (Room 1097). 
DTF-DRMCDTDPC-CC35 Beyond category 2 Same disposition as Potential Event DTF-DRMCDTDPC-CC34. Preventive Design 
36.Drop or collision of an SNF assembly from the spent fuel transfer 
machine back into or against the basket on a trolley that is being 
unloaded. (Room 1097). 
DTF-DRMCDTDPC-CC36A 
DTF-DRMCDTDPC-CC36B 
DTF-DRMCDTDPC-CC36C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
37.Drop or collision of a SNF assembly from the spent fuel transfer 
machine back onto or against another SNF assembly or 
assemblies in the basket on a trolley (Room 1097). 
DTF-DRMCDTDPC-CC37A 
DTF-DRMCDTDPC-CC37B 
DTF-DRMCDTDPC-CC37C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
38.Impact due to horizontal movement of a SNF assembly by the 
spent fuel transfer machine before the assembly is fully lifted out 
of the basket on a trolley (Room 1097). 
DTF-DRMCDTDPC-CC38A 
DTF-DRMCDTDPC-CC38B 
DTF-DRMCDTDPC-CC38C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-94 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
39.Drop and slapdown of an SNF assembly from the spent fuel 
transfer machine (due to impact with an edge of the basket, the 
floor edge, a basket internal baffle, etc.) during the SNF transfer 
from the basket on the trolley to a WP or staging rack (Room 
2048) 
DTF-DRMCDTDPC-CC39A 
DTF-DRMCDTDPC-CC39B 
DTF-DRMCDTDPC-CC39C 
No drop 
Category 2 
Category 2 
(See GET-10) Same disposition as Potential Event DTF-DRMCDTDPC-CC11. Preventive Design- 
Procedural 
Safety 
40.Drop or collision of a DPC (if not emptied), a DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO, as 
applicable, from the waste transfer cell overhead crane back into 
or against the basket on a trolley being unloaded (Room 2048). 
DTF-DRMCDTDPCCC40A 
DTF-DRMCDTDPCCC40B 
DTF-DRMCDTDPCCC40C 
DTF-DRMCDTDPCCC40D 
DTF-DRMCDTDPCCC40E 
DTF-DRMCDTDPCCC40F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Same disposition as Potential Event DTF-DRMCDTDPC-CC20. Preventive Design- 
Procedural 
Safety 
41.Impact due to horizontal movement of a DPC (if not emptied), a 
DOE HLW canister, a [standardized] DOE SNF canister, or DOE 
SNF MCO, as applicable, with the waste transfer cell overhead 
crane before the canister is completely removed from the basket 
on a trolley (Room 2048). 
DTF-DRMCDTDPC-CC41 Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force 
during a transfer to breach a transportation cask, site-specific cask, waste package, or 
canister as the result of attempts to overcome mechanical constraints. 
Preventive Design 
42.Drop or collision of a DOE HLW canister from the waste transfer 
cell crane back onto or against another DOE HLW canister, a 
[standardized] DOE SNF canister, or a DOE SNF MCO, as 
applicable, in the basket on a trolley (Room 2048). 
DTF-DRMCDTDPCCC42A 
DTF-DRMCDTDPCCC42B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
43.Drop or collision of a [standardized] DOE SNF canister from the 
waste transfer cell crane onto or against a DOE HLW canister in 
the basket on a trolley (Room 2048). 
DTF-DRMCDTDPCCC43C 
DTF-DRMCDTDPCCC43D 
DTF-DRMCDTDPCCC43E 
DTF-DRMCDTDPCCC43F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Design and operational requirements reduce the 
drop probability. A design requirement limits lift heights for DOE SNF canisters, DOE HLW 
canisters, naval canisters, DPCs, and DOE SNF multicanister overpacks. Design and 
operational requirements limit the probability of exceeding the lift height. Canister design 
requirements and the reliability of fabrication processes limit the probability that a DOE 
SNF canister or DOE multicanister overpack is defective. Design requirements ensures 
that standardized DOE SNF canisters, would withstand without breach a drop of another 
standardized DOE SNF canister and that MCOs would withstand without breach a drop of 
another MCO dropped from within its lift-height limits. Operational controls render dropping 
a DOE SNF canister on a DOE HLW canister Beyond Category 2. A design requirement 
ensures that a DOE SNF canister in a cask, WP, staging rack, or staging pit would 
withstand without breach the drop of a DOE HLW canister on top of the DOE SNF canister 
from within their lift height limits. Neither naval canisters nor MCOs are staged in staging 
racks. For collisions, a design requirement limits speed for crane transfers such that a 
collision at the maximum speed could not breach an MSC, transportation cask, transfer 
cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
44.Drop or collision of a DOE SNF MCO from the waste transfer cell 
crane onto or against another DOE SNF MCO or a DOE HLW 
canister, as applicable, in the basket on a trolley (Room 2048). 
DTF-DRMCDTDPCCC44C 
DTF-DRMCDTDPCCC44D 
DTF-DRMCDTDPCCC44E 
DTF-DRMCDTDPCCC44F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event DTFDRMCDTDPC-
CC43. 
Preventive Design- 
Procedural 
Safety 
45.Drop and slapdown of a DOE HLW canister, a DOE SNF MCO, or 
a [standardized] DOE SNF canister, as applicable, from the waste 
transfer cell overhead crane (due to impact with an edge of the 
basket, floor edge, basket internal baffle, etc.) during the transfer 
from the basket on a trolley to a new WP or staging rack (if 
applicable) (Room 2048). 
DTF-DRMCDTDPCCC45A 
DTF-DRMCDTDPCCC45B 
DTF-DRMCDTDPCCC45C 
DTF-DRMCDTDPCCC45D 
DTF-DRMCDTDPCCC45E 
DTF-DRMCDTDPCCC45F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-11) Same disposition as Potential Event DTF-DRMCDTDPC-CC20. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-95 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
46.Drop or collision of handling equipment from the spent fuel 
transfer machine into or against a basket on a trolley filled with 
SNF assemblies (Room 2048). 
DTF-DRMCDTDPCCC46A 
DTF-DRMCDTDPCCC46B 
No drop 
Category 2 
(See GET-18) Same disposition as Potential Event DTF-DRMCDTDPC-CC31. Preventive Design- 
Procedural 
Safety 
47.Drop or collision of handling equipment from the waste transfer 
cell overhead crane into or against a basket on a trolley loaded 
with DOE HLW canisters, and/or [standardized] DOE SNF 
canisters, and/or DOE SNF MCOs, as applicable (Room 2048). 
DTF-DRMCDTDPC-CC47A 
DTF-DRMCDTDPC-CC47B 
DTF-DRMCDTDPCCC47C 
DTF-DRMCDTDPCCC47D 
DTF-DRMCDTDPCCC47E 
DTF-DRMCDTDPCCC47F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) Same disposition as Potential Event DTF-DRMCDTDPC-CC32. Preventive Design- 
Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1097, 1101, 1109, 
1127, and 2048). 
DTF-DRMCDTDPC-CCF1 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a mobile elevated 
platform (Rooms 1109 and 1127). 
DTF-DRMCDTDPC-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the cask and MSC sampling 
and purging system and the ignition of hydrogen that may have 
accumulated in the cask or MSC (Room 1127). 
DTF-DRMCDTDPC-EI2 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with tools or SNF and HLW handling 
equipment in the cask docking/dry remediation room, the tool 
spare transfer room, or the DPC cutting/WP dry remediation cell 
(including the overhead cranes, overhead manipulators, turntable, 
etc.) (Rooms 1097, 1109, and 1127). 
DTF-DRMCDTDPC-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
(Rooms 1097, 1101, 1109, 1127, and 2048). 
DTF-DRMCDTDPC-FT2 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
3. Thermal hazard (from decay heat) associated with vertical 
orientation of the cask, MSC, or basket (Rooms 1097, 1109, and 
1127) 
DTF-DRMCDTDPC-FT3 Normal Operations Same disposition as Potential Event DTF-DRMCDTDPC-CCF1. Mitigative Procedural 
Safety 
4. Transient combustible fire in the cask docking/dry remediation 
room, the tool spare transfer room, or the DPC cutting/WP dry 
remediation cell (Rooms 1097, 1109, and 1127). 
DTF-DRMCDTDPC-FT4 Beyond Category 2 Same disposition as Potential Event DTF-DRMCDTDPC-FT1. Preventive Design- 
Procedural 
Safety 
5. Electrical fire associated with the trolley (Rooms 1097, 1101, 
1109, and 1127). 
DTF-DRMCDTDPC-FT5 Beyond Category 2 Same disposition as Potential Event DTF-DRMCDTDPC-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with a mobile 
elevated platform (Rooms 1109 and 1127). 
DTF-DRMCDTDPC-FT6 Beyond Category 2 Same disposition as Potential Event DTF-DRMCDTDPC-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-96 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1097, 1101, 1109, 1127, and 2048). 
DTF-DRMCDTDPC-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Damage or rupture of the cask and MSC sampling and purging 
system, leading to a release of canister internal gases and 
radioactive material (Room 1127). 
DTF-DRMCDTDPC-R2 Normal Operations The sampling operation is conducted so that exposure of workers to radiation is managed 
as a normal-operations dose by procedures for monitoring radiation doses and assigning 
work, which ensure that workers do not receive excessive radiation doses. Although a 
rupture leading to a radiological release would be an off-normal occurrence, any release 
and related dose would be managed as part of routine radiation protection operations. 
Mitigative Procedural 
Safety 
3. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1097, 1101, 1109, 1127, and 2048). 
DTF-DRMCDTDPC-R3 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
4. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Rooms 
1097, 1101, 1109, 1127, and 2048). 
DTF-DRMCDTDPC-R4 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1097, 1101, 
1109, 1127, and 2048). 
DTF-DRMCDTDPC-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley derailment (holding a cask or 
MSC requiring remediation) followed by a load tipover or fall and a 
rearrangement of the container internals (Rooms 1097, 1101, 
1109, and 1127). 
DTF-DRMCDTDPC-F1 Beyond Category 2 Same disposition as Potential Event DTF-DRMCDTDPC-CC3. Preventive Design 
2. Criticality associated with a drop of an SNF assembly from the 
DPC cutting/WP dry remediation cell crane back into the cask or 
MSC being unloaded or drop into a basket on a trolley being 
unloaded and a rearrangement of the cask, MSC, or basket 
internals (Room 1097). 
DTF-DRMCDTDPC-F2 Beyond Category 2 Design requirements and waste acceptance criteria ensure criticality safety in 
transportation casks, transfer casks, site-specific casks, CSNF baskets in dry processing 
areas, and dual-purpose canisters even with most reactive credible configuration of fissile 
material and with optimal moderation. Demonstration of compliance must account for the 
bowing of fuel rods or other rearrangement of fissile material that may occur due to a drop 
or other handling incident. 
Preventive Design 
3. Criticality associated with a drop or slapdown of a [standardized] 
DOE SNF canister, a DOE SNF MCO, or a DOE HLW canister 
from DPC cutting/WP dry remediation cell crane during cask or 
MSC unloading or basket on a trolley loading (as applicable) 
(Room 1097). 
DTF-DRMCDTDPC-F3 Beyond Category 2 A design requirement ensures that dropping a DOE SNF canister within its design basis 
does not lead to a criticality. Demonstration of compliance for the staging rack must 
account for the most reactive configuration of DOE SNF canisters with credit for moderator 
control. Design and operational requirements ensure that moderator control is in effect. 
There is no potential for criticality of DOE HLW canisters. 
Preventive Design- 
Procedural 
Safety 
4. Criticality associated with a trolley (holding a basket containing 
SNF assemblies, a naval SNF canister, or various combinations of 
[standardized] DOE SNF canisters, DOE SNF MCOs, or DOE 
HLW canisters) derailment followed by a load tipover or fall and a 
rearrangement of the basket contents (Rooms 1097, 1101, 
1109, and 1127). 
DTF-DRMCDTDPC-F4 Beyond Category 2 Same disposition as Potential Event DTF-DRMCDTDPC-F1. Preventive Design 
5. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine back into the basket on a trolley being 
unloaded and a rearrangement of the basket contents (Room 
2048). 
DTF-DRMCDTDPC-F5 Beyond Category 2 Same disposition as Potential Events DTF-DRMCDTDPC-F2. Additionally, results of 
criticality analyses ensure that drops, collisions, and other handling impacts of a 
commercial SNF assembly, allowing for rearrangement of fuel rods and without credit for 
burnup or moderator control, do not pose a criticality safety concern. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-97 April 2005 
Table III-20. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Dry Remediation): Cask Docking/Dry Remediation Room (Room 1109), Tool Spare Transfer Room (Room 1127), Dual-purpose Canister Cutting/Waste Package Dry 
Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
6. Criticality associated with a drop of an SNF assembly from the 
DPC cutting/WP dry remediation cell crane back into the cask or 
MSC being unloaded or onto the DPC cutting/WP dry remediation 
cell floor and a rearrangement of the fuel rods that comprise the 
assembly due to impact (Room 1097). 
DTF-DRMCDTDPC-F6 Beyond Category 2 Same disposition as Potential Events DTF-DRMCDTDPC-F5. Preventive Design 
7. Criticality associated with a drop or slapdown of a [standardized] 
DOE SNF canister, a DOE SNF MCO, or a DOE HLW canister 
from waste transfer cell crane during the unloading of the basket 
on a trolley (as applicable) (Room 2048). 
DTF-DRMCDTDPC-F7 Beyond Category 2 Same disposition as Potential Events DTF-DRMCDTDPC-F3. Preventive Design- 
Procedural 
Safety 
8. Criticality associated with the drop of heavy equipment (lifting 
fixture, etc.) onto a basket on a trolley and a rearrangement of the 
basket contents (Room 1097). 
DTF-DRMCDTDPC-F8 Beyond Category 2 An operational requirement establishes limited lift heights of heavy equipment above an 
SNF assembly, a DOE SNF or HLW canister, or a DPC in a fuel basket on a trolley in the 
dry remediation area such that criticality as the result of equipment drop is precluded with 
moderator control in effect. 
Preventive Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; DRMCDTDPC = dry remediation cask docking tool dual purpose canister; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = 
high-level radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example DRMCDTDPC, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
Additional room(s) with potential events in this table: Room 1069  Cask and MSC docking room; Room 1073 - Cask/MSC turntable room; Room 1074 - Cask preparation room; Room 1100 - DPC preparation/cask dry remediation; Room 1101 - DPC docking room; Room 2048 - 
Waste transfer cell. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-98 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the trolley (holding the cask or MSC to be 
remediated) and the doors to the cask wet remediation entrance 
vestibule, the shield doors between the cask wet remediation 
entrance vestibule and the cask wet remediation-laydown area, or 
the shield doors between the DPC docking room and the cask wet 
remediation-laydown area (Rooms 1117 and 1120). 
DTF-WREMLDEV-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. Doors to the cask wet remediation entrance vestibule, the shield 
doors between the cask wet remediation entrance vestibule and 
the cask wet remediation/laydown area, or the shield doors 
between the DPC docking room and the cask wet 
remediation/laydown area close on the trolley (holding the cask or 
MSC to be remediated) (Rooms 1117 and 1120). 
DTF-WREMLDEV-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to 
drop its load. A design requirement ensures that closure of airlock doors, shield doors, 
and other applicable doors on a transportation cask, transfer cask, or MSC suspended 
from an overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of a trolley in the cask wet remediation/laydown area 
while holding a cask or MSC to be remediated, followed by a load 
tipover or fall (Rooms 1117 and 1120). 
DTF-WREMLDEV-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their 
loads. Design requirements apply to trolleys for casks, waste packages, site-specific 
casks, and dual-purpose canisters. 
Preventive Design 
4. SRTC derailment involving a loaded cask (with or without impact 
limiters installed) or MSC (Rooms 1117 and 1120). 
DTF-WREMLDEV-CC4 Beyond Category 2 A design requirement ensures that the SRTC carrying a cask without impact limiters 
(typically only within structures) or a site-specific cask does not derail and the cask or 
site-specific cask does not fall off the SRTC under normal operating conditions or as the 
result of a collision. 
Preventive Design 
5. Collision of an SRTC carrying a loaded cask (with or without 
impact limiters installed) or MSC with the cask wet remediation 
entrance vestibule doors or the cask wet remediation-laydown 
area shield doors (Rooms 1117 and 1120) 
DTF-WREMLDEV-CC5 Beyond Category 2 Design and operational requirements establish speed limits such that a collision with 
shield or airlock doors or other heavy objects would not overturn an SRTC, or sitespecific 
cask transporter or cause it to lose its load. 
Preventive Design- 
Procedural 
Safety 
6. Cask wet remediation entrance vestibule doors or the cask wet 
remediation/laydown area shield doors close on an SRTC carrying 
a loaded cask (with or without impact limiters installed) or MSC 
(Rooms 1117 and 1120). 
DTF-WREMLDEV-CC6 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC2. Preventive Design 
7. Collision of a mobile elevated platform with a loaded cask or MSC 
during removal of personnel barriers and impact limiters (if 
applicable) or during survey activities (Room 1117). 
DTF-WREMLDEV-CC7 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a 
manner that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
8. Drop or collision of personnel barriers or impact limiters from the 
cask wet remediation/laydown area crane onto or against a 
loaded cask (if applicable) (Room 1117). 
DTF-WREMLDEV-CC8 Beyond Category 2 An operational requirement ensures that the equipment associated with cask handling 
and preparation is not capable of breaching a transportation cask, with or without impact 
limiters, or a site-specific cask if collided against the cask or dropped onto the cask from 
the lift-height limit. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-99 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Slapdown of a loaded cask onto an SRTC during upending of the 
loaded cask to the vertical orientation (Room 1117). 
DTF-WREMLDEV-CC9A 
DTF-WREMLDEV-CC9B 
DTF-WREMLDEV-CC9C 
DTF-WREMLDEV-CC9D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact 
limiters and site-specific casks. Design and operational requirements limit the probability 
of exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. 
Preventive Design- 
Procedural 
Safety 
10.Drop and slapdown of a loaded MSC onto an SRTC or the floor 
during the lift of the loaded MSC off of the SRTC (Room 1117). 
DTF-WREMLDEV-CC10A 
DTF-WREMLDEV-CC10B 
DTF-WREMLDEV-CC10C 
DTF-WREMLDEV-CC10D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event DTF-WREMLDEV-CC9. Preventive Design- 
Procedural 
Safety 
11. Drop of a loaded cask or MSC from the overhead bridge crane 
onto the floor during transfer from the trolley or SRTC to the cask 
decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC11A 
DTF-WREMLDEV-CC11B 
DTF-WREMLDEV-CC11C 
DTF-WREMLDEV-CC11D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact 
limiters and site-specific casks. Design and operational requirements limit the probability 
of exceeding the lift height. An operational requirement prohibits carrying a cask or MSC 
over or near the SNF assembly staging rack in the pool. Canister design requirements 
and the reliability of fabrication processes limit the probability that a DOE SNF canister or 
DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
12.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane onto or against a sharp object during transfer from 
the trolley or SRTC to the cask decontamination pit/cask prep pit 
(Room 1117). 
DTF-WREMLDEV-CC12 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through 
which WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer 
casks, or MSCs are transferred by crane are kept free of structures, such as posts and 
curbs, that could puncture a container in case of a drop. An operational requirement 
ensures that the load paths are kept free of movable puncture hazards. A design 
requirement limits speed for crane transfers such that a collision at the maximum speed 
could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
13.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane into or against the cask decontamination pit/cask 
prep pit during transfer from the trolley or SRTC to the cask 
decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC13A 
DTF-WREMLDEV-CC13B 
DTF-WREMLDEV-CC13C 
DTF-WREMLDEV-CC13D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. For 
collisions, a design requirement limits speed for crane transfers such that a collision at 
the maximum speed could not breach an MSC, transportation cask, transfer cask, DPC, 
DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
14.Tipover or slapdown of a loaded cask or MSC from the overhead 
bridge crane into the cask decontamination pit/cask prep pit or 
onto the floor due to contact with the pit ledge or access platform 
during transfer from the trolley or SRTC to the cask 
decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC14A 
DTF-WREMLDEV-CC14B 
DTF-WREMLDEV-CC14C 
DTF-WREMLDEV-CC14D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety - 
15.Drop or collision of handling equipment (including the cask lifting 
yoke, cask skirt, cask skirt lifting beam, and cask immersion rod) 
onto or against the cask or MSC before or after transfer of the 
cask to the cask decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC15 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC8. Preventive Procedural 
Safety 
16. Collision involving an access platform and a cask or MSC in the 
cask decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC16 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC7. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-100 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
17.Drop or collision of the cask lid bolt detorque machine or other 
cask prep equipment onto or against a loaded cask or MSC or 
cask or MSC inner lid (including a lid-lifting fixture, cask gas 
sample/purge system equipment, cask cool-down equipment, etc.) 
(Room 1117). 
DTF-WREMLDEV-CC17 Beyond Category 2 An operational requirement ensures that the lift height permitted for the lid-bolt detorque 
machines in the dry-handling cell and the pool area are such that the lid of the 
transportation cask or site-specific cask, without credit for the bolts, are able to prevent a 
potential radiological release should the detorque machine fall onto or collide with the 
transportation cask. 
Preventive Procedural 
Safety 
18.Drop of a cask or MSC outer lid from the overhead crane onto the 
cask or MSC (Room 1117). 
DTF-WREMLDEV-CC18A 
DTF-WREMLDEV-CC18B 
DTF-WREMLDEV-CC18C 
DTF-WREMLDEV-CC18D 
DTF-WREMLDEV-CC18E 
DTF-WREMLDEV-CC18F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. 
Design and operational requirements limit the probability of exceeding the lift height. 
Canister design requirements and the reliability of fabrication processes limit the 
probability that a DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
19.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane back into or against a pit during transfer from the 
cask decontamination pit/cask prep pit into the pool (Room 1117). 
DTF-WREMLDEV-CC19A 
DTF-WREMLDEV-CC19B 
DTF-WREMLDEV-CC19C 
DTF-WREMLDEV-CC19D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC13. Preventive Design- 
Procedural 
Safety 
20. Drop of a loaded cask or MSC from the overhead bridge crane 
onto the cell floor during transfer from the cask decontamination 
pit/cask prep pit into the pool (Room 1117). 
DTF-WREMLDEV-CC20A 
DTF-WREMLDEV-CC20B 
DTF-WREMLDEV-CC20C 
DTF-WREMLDEV-CC20D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
21.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane onto or against a sharp object during transfer from 
the cask decontamination pit/cask prep pit into the pool (Room 
1117). 
DTF-WREMLDEV-CC21 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC12. Preventive Design- 
Procedural 
Safety 
22. Drop of a loaded cask or MSC from the overhead bridge crane 
onto the pool floor during transfer from the cask decontamination 
pit/cask prep pit into the pool (Room 1117). 
DTF-WREMLDEV-CC22A 
DTF-WREMLDEV-CC22B 
DTF-WREMLDEV-CC22C 
DTF-WREMLDEV-CC22D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety - 
23.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane onto or against an empty cask or MSC already in the 
pool during transfer from the cask decontamination pit/cask prep 
pit into the pool (Room 1117). 
DTF-WREMLDEV-CC23A 
DTF-WREMLDEV-CC23B 
DTF-WREMLDEV-CC23C 
DTF-WREMLDEV-CC23D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC13. Preventive Design- 
Procedural 
Safety 
24.Tipover or slapdown of a loaded cask or MSC from the overhead 
bridge crane (due to impact with the pool edge or ledge/wall in the 
pool) into the pool during transfer from the cask decontamination 
pit/cask prep pit into the pool (Room 1117). 
DTF-WREMLDEV-CC24A 
DTF-WREMLDEV-CC24B 
DTF-WREMLDEV-CC24C 
DTF-WREMLDEV-CC24D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
25.Drop or collision of handling equipment (or other equipment, 
including an immersion rod) onto or against the lid of a loaded 
cask or MSC positioned in the pool prior to, or after, the cask or 
MSC lid removal or installation process, respectively (Room 
1117). 
DTF-WREMLDEV-CC25 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC8. Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-101 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
26. Collision involving a lid suspended in the pool from the fuel 
transfer machine removing (or installing) the cask or MSC lid 
during the lid removal (or installation) process in the pool (Room 
1117). 
DTF-WREMLDEV-CC26A 
DTF-WREMLDEV-CC26B 
DTF-WREMLDEV-CC26C 
DTF-WREMLDEV-CC26D 
DTF-WREMLDEV-CC26E 
DTF-WREMLDEV-CC26F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Same disposition as Potential Event DTF-WREMLDEV-CC18. Preventive Design- 
Procedural 
Safety 
27.Drop of a cask or MSC inner lid onto or into a loaded cask or MSC 
from the fuel handling machine during the lid removal (or 
installation) process in the pool (Room 1117). 
DTF-WREMLDEV-CC27A 
DTF-WREMLDEV-CC27B 
DTF-WREMLDEV-CC27C 
DTF-WREMLDEV-CC27D 
DTF-WREMLDEV-CC27E 
DTF-WREMLDEV-CC27F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Same disposition as Potential Event DTF-WREMLDEV-CC18. Preventive Design- 
Procedural 
Safety 
28.Drop or collision of an empty cask or MSC from the overhead 
bridge crane onto or against the cask or MSC already in the pool 
(to be unloaded) during the lowering of the empty cask or MSC 
into the pool (Room 1117). 
DTF-WREMLDEV-CC28 Beyond Category 2 For drops, an operational requirement prohibits carrying an empty cask in the DTF 
remediation pool above a transportation cask, MSC, or basket that contains CSNF. For 
collisions, a design requirement limits speed for crane transfers such that a collision at 
the maximum speed could not breach an MSC, transportation cask, transfer cask, DPC, 
DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
29.Drop or collision of the cask or MSC lid from the empty cask or 
MSC onto or against the unsealed (open) cask to be unloaded 
(Room 1117). 
DTF-WREMLDEV-CC29A 
DTF-WREMLDEV-CC29B 
DTF-WREMLDEV-CC29C 
DTF-WREMLDEV-CC29D 
DTF-WREMLDEV-CC29E 
DTF-WREMLDEV-CC29F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Same disposition as Potential Event DTF-WREMLDEV-CC18. Preventive Design- 
Procedural 
Safety 
30.Drop or collision of an empty SNF basket onto or against the cask 
to be unloaded (Room 1117). 
DTF-WREMLDEV-CC30 Beyond Category 2 Operational requirements ensure that an SNF assembly basket or basket grapple 
dropped or collided against another basket or a cask in the pool does not damage SNF 
assemblies in the basket or cask already in place. 
Preventive Procedural 
Safety 
31.Drop or collision of an empty or full canister for damaged SNF 
onto or against the cask being unloaded (Room 1117). 
DTF-WREMLDEV-CC31A 
DTF-WREMLDEV-CC31B 
DTF-WREMLDEV-CC31C 
No collision 
Category 2 
Category 2 
(See GET-15) Design and operational requirements for commercial SNF handling 
equipment reduce the drop rate and collision probabilities for commercial SNF assembly 
transfers, including those in single-assembly canisters. To avoid a drop or collision 
involving an empty canister that could lead to a radiological release, an operational 
requirement prohibits suspending an empty canister above an open cask, MSC, or CSNF 
basket that contains CSNF 
Preventive Design- 
Procedural 
Safety 
32.Drop or collision of an empty or full canister for damaged SNF 
onto or against the empty or full SNF basket being loaded 
(Room 1117). 
DTF-WREMLDEV-CC32A 
DTF-WREMLDEV-CC32B 
DTF-WREMLDEV-CC32C 
No collision 
Category 2 
Category 2 
(See GET-15) Same disposition as Potential Event DTF-WREMLDEV-CC31. Preventive Design- 
Procedural 
Safety 
33.Drop of an SNF assembly onto the pool floor while suspended 
from the fuel handling machine during transfer from the cask to 
the SNF basket or to the empty cask or MSC in the pool (Room 
1117). 
DTF-WREMLDEV-CC33A 
DTF-WREMLDEV-CC33B 
DTF-WREMLDEV-CC33C 
No collision 
Category 2 
Category 2 
(See GET-16) Design and operational requirements for commercial SNF handling 
equipment reduce the drop rate and collision probabilities for commercial SNF assembly 
transfers, including those in single-assembly canisters. 
Preventive Design- 
Procedural 
Safety 
34.Drop or collision of an SNF assembly onto or against a sharp 
object while suspended from the fuel handling machine during 
transfer from the cask to the SNF basket or to the empty cask or 
MSC in the pool (Room 1117). 
DTF-WREMLDEV-CC34A 
DTF-WREMLDEV-CC34B 
DTF-WREMLDEV-CC34C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-102 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
35.Drop or collision of an SNF assembly back into or against the 
cask or MSC while suspended from the fuel handling machine 
during transfer from the cask to the SNF basket or to the empty 
cask or MSC in the pool (Room 1117). 
DTF-WREMLDEV-CC35A 
DTF-WREMLDEV-CC35B 
DTF-WREMLDEV-CC35C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
36.Drop or collision of an SNF assembly onto or against another 
assembly or assemblies in the cask or MSC while suspended 
from the fuel handling machine during transfer from the cask to 
the SNF basket or to the empty cask or MSC in the pool (Room 
1117). 
DTF-WREMLDEV-CC36A 
DTF-WREMLDEV-CC36B 
DTF-WREMLDEV-CC36C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
37.Impact due to horizontal movement of an SNF assembly by the 
spent fuel transfer machine before the assembly is fully lifted out 
of the cask or MSC (Room 1117). 
DTF-WREMLDEV-CC37A 
DTF-WREMLDEV-CC37B 
DTF-WREMLDEV-CC37C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
38.Drop or collision of an SNF assembly into or against the empty 
SNF basket in the pool while suspended from the fuel handling 
machine during transfer from the cask or MSC to an empty 
location in the SNF basket (Room 1117). 
DTF-WREMLDEV-CC38A 
DTF-WREMLDEV-CC38B 
DTF-WREMLDEV-CC38C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
39.Drop or collision of an SNF assembly onto or against another fuel 
assembly or assemblies in the SNF basket in the pool while 
suspended from the fuel handling machine during transfer from 
the cask or MSC to an empty location in the SNF basket (Room 
1117). 
DTF-WREMLDEV-CC39A 
DTF-WREMLDEV-CC39B 
DTF-WREMLDEV-CC39C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
40. Collision of the fuel handling machine basket grapple with a filled 
SNF basket during the closing (or opening) of the SNF basket 
(Room 1117). 
DTF-WREMLDEV-CC40 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC30. Preventive Procedural 
Safety 
41. Drop of a filled SNF basket from the fuel handling machine onto 
the pool floor during transfer of the filled SNF basket to (or from) 
the pool area basket storage rack (Room 1117). 
DTF-WREMLDEV-CC41A 
DTF-WREMLDEV-CC41B 
No drop 
Category 2 
(See GET-17) Design and operational requirements for commercial SNF handling 
equipment reduce the drop rate for commercial SNF assembly transfers, including those 
in single-assembly canisters. 
Preventive Design- 
Procedural 
Safety 
42.Drop or collision of a filled SNF basket from the fuel handling 
machine onto or against a sharp object during transfer of the filled 
SNF basket to (or from) the pool area basket storage rack 
(Room 1117). 
DTF-WREMLDEV-CC42A 
DTF-WREMLDEV-CC42B 
No drop 
Category 2 
(See GET-17) Same disposition as Potential Event DTF-WREMLDEV-CC41. Preventive Design- 
Procedural 
Safety 
43.Drop or collision of a filled SNF basket from the fuel handling 
machine onto, into, or against the cask or MSC being unloaded or 
loaded (containing SNF) during transfer of the filled SNF basket to 
or from the pool area basket storage rack (Room 1117). 
DTF-WREMLDEV-CC43A 
DTF-WREMLDEV-CC43B 
No drop 
Category 2 
(See GET-17) Same disposition as Potential Event DTF-WREMLDEV-CC41. Preventive Design- 
Procedural 
Safety 
44.Drop or collision of a filled SNF basket from the fuel handling 
machine onto or against an empty basket storage rack location 
during transfer of the filled SNF basket to (or from) the pool area 
basket storage rack (Room 1117). 
DTF-WREMLDEV-CC44A 
DTF-WREMLDEV-CC44B 
No drop 
Category 2 
(See GET-17) Same disposition as Potential Event DTF-WREMLDEV-CC41. Preventive Design- 
Procedural 
Safety 
45.Drop or collision of a filled SNF basket from the fuel handling 
machine onto or against a filled basket storage rack location (onto 
another filled SNF basket) during transfer of the filled SNF basket 
to (or from) the pool area basket storage rack (Room 1117). 
DTF-WREMLDEV-CC45A 
DTF-WREMLDEV-CC45B 
No drop 
Category 2 
(See GET-17) Same disposition as Potential Event DTF-WREMLDEV-CC41. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-103 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
46.Drop or collision of handling equipment from the fuel handling 
machine onto or against an SNF assembly or assemblies in the 
SNF basket (before or after transfer to pool area basket 
storage rack) (Room 1117). 
DTF-WREMLDEV-CC46A 
DTF-WREMLDEV-CC46B 
No drop 
Category 2 
(See GET-12) Design and operational requirements reduce the probability of dropping 
handling equipment onto a SNF assembly energetically enough to breach the assembly. 
For collisions, a design requirement ensures that the spent fuel transfer machine, fuel 
handling machine and other equipment designed to handle individual SNF assemblies 
are not capable of lateral movements of handling equipment at a speed that could initiate 
an event sequence as a result of collision with a SNF assembly. 
Preventive Design- 
Procedural 
Safety 
47.Drop of an SNF assembly onto the pool floor while suspended 
from the fuel handling machine during transfer to an empty cask 
or MSC from the SNF basket (Room 1117). 
DTF-WREMLDEV-CC47A 
DTF-WREMLDEV-CC47B 
DTF-WREMLDEV-CC47C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
48.Drop of an SNF assembly onto or against a sharp object while 
suspended from the fuel handling machine during transfer to an 
empty cask or MSC from the SNF basket (Room 1117). 
DTF-WREMLDEV-CC48A 
DTF-WREMLDEV-CC48B 
DTF-WREMLDEV-CC48C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
49.Impact due to horizontal movement of an SNF assembly by the 
fuel handling machine before the assembly is fully lifted out of the 
SNF basket (Room 1117). 
DTF-WREMLDEV-CC49A 
DTF-WREMLDEV-CC49B 
DTF-WREMLDEV-CC49C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
50.Drop or collision of an SNF assembly back into or against the SNF 
basket being unloaded in the pool while suspended from the fuel 
handling machine during transfer to an empty cask or MSC 
(Room 1117). 
DTF-WREMLDEV-CC50A 
DTF-WREMLDEV-CC50B 
DTF-WREMLDEV-CC50C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
51.Drop or collision of an SNF assembly onto or against another 
assembly or assemblies in the SNF basket in the pool while 
suspended from the fuel handling machine during transfer to an 
empty cask or MSC (Room 1117). 
DTF-WREMLDEV-CC51A 
DTF-WREMLDEV-CC51B 
DTF-WREMLDEV-CC51C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
52.Drop or collision of an SNF assembly into or against an empty 
MSC in the pool while suspended from the fuel handling machine 
during transfer to an empty location in a cask or MSC from the 
SNF basket (Room 1117). 
DTF-WREMLDEV-CC52A 
DTF-WREMLDEV-CC52B 
DTF-WREMLDEV-CC52C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
53.Drop or collision of a SNF assembly onto or against another fuel 
assembly or assemblies inside the MSC in the pool while 
suspended from the fuel handling machine during transfer to an 
empty location in a cask or MSC from the SNF basket (Room 
1117). 
DTF-WREMLDEV-CC53A 
DTF-WREMLDEV-CC53B 
DTF-WREMLDEV-CC53C 
No collision 
Category 2 
Category 2 
(See GET-16) Same disposition as Potential Event DTF-WREMLDEV-CC33. Preventive Design- 
Procedural 
Safety 
54.Drop or collision of an empty SNF basket onto or against a filled 
cask or MSC during movement of the empty SNF basket (after 
closure of the basket) back to the pool area basket storage rack 
(Room 1117). 
DTF-WREMLDEV-CC54 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC30. Preventive Procedural 
Safety 
55.Drop or collision of handling equipment or a lid (or other 
equipment), either from the overhead bridge crane, maintenance 
crane, or from the fuel handling machine, onto or against an SNF 
assembly or assemblies in an open unsealed cask or MSC 
positioned at the bottom of the pool (Room 1117). 
DTF-WREMLDEV-CC55aA 
DTF-WREMLDEV-CC55aB 
DTF-WREMLDEV-CC55bA 
DTF-WREMLDEV-CC55bB 
DTF-WREMLDEV-CC55bC 
DTF-WREMLDEV-CC55bD 
DTF-WREMLDEV-CC55bE 
DTF-WREMLDEV-CC55bF 
No drop 
Category 2 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
CC55a. (See GET-12 for handling equipment events) Same disposition as Potential 
Event DTF-WREMLDEV-CC46. 
CC55b. (Bounded by GET-02 for lid events) Same disposition as Potential Event DTFWREMLDEV-
CC18. 
Preventive 
Preventive 
Design- 
Procedural 
Safety 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-104 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
56.Drop or collision of handling equipment (or other equipment) from 
the overhead bridge crane onto or against a loaded cask or MSC 
positioned at the bottom of the pool after the lid has been 
installed, prior to removal from the pool (Room 1117). 
DTF-WREMLDEV-CC56 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC8. Preventive Procedural 
Safety 
57. Drop of a loaded cask or MSC from the overhead bridge crane 
onto the pool floor during transfer from the pool to the cask 
decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC57A 
DTF-WREMLDEV-CC57B 
DTF-WREMLDEV-CC57C 
DTF-WREMLDEV-CC57D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
58.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane onto or against a sharp object in the pool during 
transfer out of the pool to the cask decontamination pit/cask prep 
pit (Room 1117). 
DTF-WREMLDEV-CC58 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC12. Preventive Design- 
Procedural 
Safety 
59.Tipover or slapdown of a loaded cask or MSC into the cask 
decontamination pit/cask prep pit from the overhead bridge crane 
due to impact with the pit edge or access platform in the pit during 
transfer from the pool to the cask decontamination pit/cask prep 
pit (Room 1117). 
DTF-WREMLDEV-CC59A 
DTF-WREMLDEV-CC59B 
DTF-WREMLDEV-CC59C 
DTF-WREMLDEV-CC59D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
60.Tipover or slapdown of a loaded cask or MSC into the pool from 
the overhead bridge crane due to impact with the pool edge or 
ledge/wall in the pool during transfer from the pool to the cask 
decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC60A 
DTF-WREMLDEV-CC60B 
DTF-WREMLDEV-CC60C 
DTF-WREMLDEV-CC60D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
61.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane into or against the cask decontamination pit/cask 
prep pit during transfer from the pool to the cask decontamination 
pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC61A 
DTF-WREMLDEV-CC61B 
DTF-WREMLDEV-CC61C 
DTF-WREMLDEV-CC61D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC13. Preventive Design- 
Procedural 
Safety 
62. Drop of a loaded cask or MSC from the overhead bridge crane 
onto the wet remediation area floor during transfer from the pool 
to the cask decontamination pit/cask prep pit or from the cask 
decontamination pit/cask prep pit to a trolley (Room 1117). 
DTF-WREMLDEV-CC62A 
DTF-WREMLDEV-CC62B 
DTF-WREMLDEV-CC62C 
DTF-WREMLDEV-CC62D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
63. Drop of a loaded cask or MSC from the overhead bridge crane 
onto the trolley during the transfer from the cask decontamination 
pit/cask prep pit to a trolley (Room 1117). 
DTF-WREMLDEV-CC63A 
DTF-WREMLDEV-CC63B 
DTF-WREMLDEV-CC63C 
DTF-WREMLDEV-CC63D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
64.Drop or collision of a loaded cask or MSC from the overhead 
bridge crane onto or against a sharp object in the cask wet 
remediation/laydown area during transfer from the pool to the 
cask decontamination pit/cask prep pit or from the cask 
decontamination pit/cask prep pit to a trolley (Room 1117). 
DTF-WREMLDEV-CC64 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC12. Preventive Design- 
Procedural 
Safety 
65.Slapdown of a loaded cask or MSC following a drop from the 
overhead bridge crane (due to contact with the edge of a trolley or 
trolley pedestal) during the lift from the cask decontamination 
pit/cask prep pit to the trolley (Room 1117). 
DTF-WREMLDEV-CC65A 
DTF-WREMLDEV-CC65B 
DTF-WREMLDEV-CC65C 
DTF-WREMLDEV-CC65D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-13) Same disposition as Potential Event DTF-WREMLDEV-CC11. Preventive Design- 
Procedural 
Safety 
66.Drop or collision of an unloaded cask from the overhead bridge 
crane onto or against a loaded cask or MSC in the pool during 
transfer of the empty cask from the pool (Room 1117). 
DTF-WREMLDEV-CC66 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC28. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-105 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
67. Collision involving an access platform and a loaded cask or MSC 
in the cask decontamination pit/cask prep pit (Room 1117). 
DTF-WREMLDEV-CC67 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC7. Preventive Procedural 
Safety 
68.Drop of a cask or MSC outer lid from the overhead crane onto the 
loaded cask or MSC (Room 1117). 
DTF-WREMLDEV-CC68A 
DTF-WREMLDEV-CC68B 
DTF-WREMLDEV-CC68C 
DTF-WREMLDEV-CC68D 
DTF-WREMLDEV-CC68E 
DTF-WREMLDEV-CC68F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Same disposition as Potential Event DTF-WREMLDEV-CC18. Preventive Design- 
Procedural 
Safety 
69.Drop or collision of equipment (including the lifting yoke, cask 
skirt, cask skirt lifting beam, etc.), the lid bolt torque machine, dry 
vacuum equipment, leak test equipment, flushing equipment, etc., 
or other cask preparation or decontamination equipment, onto or 
against a loaded cask or MSC or cask or MSC inner lid (Room 
1117). 
DTF-WREMLDEV-CC69 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC8. Preventive Procedural 
Safety 
70.Drop or collision of handling equipment (including the cask 
lifting yoke) onto or against a cask or MSC before or after transfer 
of the loaded, sealed cask or MSC to the trolley (Room 1117). 
DTF-WREMLDEV-CC70 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC8. Preventive Procedural 
Safety 
71.Derailment of a trolley holding a loaded, sealed, remediated 
cask or MSC followed by a load tipover or fall (Room 1117). 
DTF-WREMLDEV-CC71 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC3. Preventive Design 
72. Collision of a trolley holding a loaded, sealed, remediated cask, 
or MSC with the shield doors separating the cask wet 
remediation/laydown area and the DPC docking room (Room 
1117). 
DTF-WREMLDEV-CC72 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
73.Shield doors separating the cask wet remediation/laydown area 
and the DPC docking room close on a trolley holding a loaded, 
sealed, remediated cask or MSC (Room 1117). 
DTF-WREMLDEV-CC73 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC2. Preventive Design 
Chemical Contamination- 
Flooding 
1. Uncontrolled pool water draindown resulting in flooding (including 
a draindown resulting from a puncture of the pool liner due to a 
cask drop) (Room 1117). 
DTF-WREMLDEV-CCF1 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CCF2. Additionally, A design 
requirement ensures that the pool and pool area in the remediation system are designed 
such that any lost water can be replaced with make-up water until the cause of the loss is 
corrected or waste forms are removed from the pool. Design and operational 
requirements ensure that the remediation pool is designed with the appropriate impactabsorbing 
capability and limitations on heavy load carrying cranes to prevent loss of pool 
integrity, given a drop of the most challenging cask into the pool. 
Preventive Design- 
Procedural 
Safety 
2. Uncontrolled pool water overfill resulting in flooding (including an 
overfill resulting from cask or MSC placement into an overfilled 
pool, malfunction of make-up water equipment, etc.) (Room 
1117). 
DTF-WREMLDEV-CCF2 Beyond Category 2 A design requirement ensures that flooding of areas of the facility where moderators are 
controlled is precluded by passive design features such as drains, flood control channels, 
curbs, elevated processing areas, and walls. 
Preventive Design- 
Procedural 
Safety 
3. Cask decontamination pit/cask prep pit flooding due to pool 
overfill, flooding, pool equipment malfunction, cask preparation 
system (cask cooling) equipment malfunction, etc. (Room 1117). 
DTF-WREMLDEV-CCF3 Beyond Category 2 The only hazard due to flooding involves the possibility of criticality due to moderator 
intrusion. Design requirements and waste acceptance criteria ensure criticality safety in 
transportation casks, transfer casks, site-specific casks, and dual-purpose canisters with 
the most reactive credible configuration of fissile material and optimal moderation. 
Preventive Design 
4. Uncontrolled water spill from the cask decontamination system or 
the cask preparation system (cask cooling) in the cask wet 
remediation/laydown area (Room 1117). 
DTF-WREMLDEV-CCF4 Beyond Category 2 Same disposition as Potential Event WREMLDEV-CCF3. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-106 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
5. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1117). 
DTF-WREMLDEV-CCF5 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to 
radiation is managed as a normal-operations dose by procedures that ensure that 
workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a trolley (Room 1117). DTF-WREMLDEV-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the cask sampling and purging 
system and the ignition of hydrogen that may have accumulated in 
the cask or MSC (Room 1117). 
DTF-WREMLDEV-EI2 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventive Procedural 
Safety 
3. Cask cooling system (nitrogen, air, etc.) or MSC drying system (or 
other pneumatic or pressurized system) missile due to fractured 
nozzle/valve stem/pneumatic device (Room 1117). 
DTF-WREMLDEV-EI3 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate 
missiles, energetic enough to penetrate a transportation cask with or without impact 
limiters, a transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, 
the inner lid of a transportation cask, a site-specific cask, a waste package, or the inner 
lid of a site-specific cask or waste package are not present in areas where potentially 
vulnerable items may be exposed. 
Preventive Procedural 
Safety 
4. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1117). 
DTF-WREMLDEV-EI4 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-EI1. Preventive Procedural 
Safety 
5. Steam explosion or cask overpressurization due to insufficient 
cooling of a cask or MSC contents prior to insertion of the cask or 
MSC into the pool (Room 1117). 
DTF-WREMLDEV-EI5 Beyond Category 2 An operational requirement ensures that quenching operations involving casks and sitespecific 
casks holding SNF to be unloaded in the remediation pool are conducted to 
avoid initiation of event sequences due to induced thermal stresses or steam explosion 
due to insufficient cooling. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fires associated with the vacuum drier, pool water 
makeup equipment, or other pool-related equipment 
(Room 1117). 
DTF-WREMLDEV-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with SNF and HLW handling equipment 
or other associated equipment in the cask wet 
remediation/laydown area and cask wet remediation entrance 
vestibule (including the cask lid bolt detorque device, the 
turntable, overhead manipulators, overhead bridge cranes, the 
fuel handling machine, etc.) (Room 1117). 
DTF-WREMLDEV-FT2 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-FT1. Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) associated with the trolley 
(Room 1117). 
DTF-WREMLDEV-FT3 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) associated with the mobile 
elevated platform (Room 1117). 
DTF-WREMLDEV-FT4 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-107 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
5. Diesel fuel fire/explosion involving an SRTC tractor pushing an 
SRTC holding a transportation cask or MSC into the cask wet 
remediation entrance vestibule (Rooms 1117 and 1120). 
DTF-WREMLDEV-FT5 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-FT1. Preventive Design- 
Procedural 
Safety 
6. Overheating of SNF due to loss of pool water, including events 
that could lead to such a loss, including the breakdown of the pool 
water cooling system, resulting in excessive cladding temperature 
and possible zircaloy cladding (or other cladding) unzipping 
(Room 1117). 
DTF-WREMLDEV-FT6 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CCF1. Preventive Design- 
Procedural 
Safety 
7. Rapid cooling of SNF assemblies, leading to excessive thermal 
stresses in the SNF cladding (Room 1117). 
DTF-WREMLDEV-FT7 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-EI5. Preventive Procedural 
Safety 
8. Damage to SNF due to insufficient cooling of a cask prior to 
lowering it into the pool, resulting in a thermal shock that damages 
the SNF cladding (Room 1117). 
DTF-WREMLDEV-FT8 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-EI5. Preventive Procedural 
Safety 
9. Intact or non-intact SNF overheating due to a loss of cooling 
resulting in excessive temperature and possible zircaloy cladding 
(or other cladding) unzipping or cladding failure due to excessive 
hoop stresses (Room 1117). 
DTF-WREMLDEV-FT9 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is 
maintained. Design and operational requirements ensure that the thermal response of 
areas where CSNF assemblies are handled or staged to a loss of HVAC would not 
cause radiological releases in excess of those considered in the consequence analysis 
for normal operations. 
Preventive Design- 
Procedural 
Safety 
10.Thermal hazard (from decay heat) associated with vertical 
orientation of a cask or MSC (Room 1117). 
DTF-WREMLDEV-FT10 Normal Operations Same disposition as Potential Event DTF-WREMLDEV-CCF5. Mitigative Procedural 
Safety 
11.Transient combustible fire in the cask wet remediation/laydown 
area or the cask wet remediation entrance vestibule (Rooms 1117 
and 1120). 
DTF-WREMLDEV-FT11 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Damage or rupture of the cask sampling and purging system, 
leading to a release of internal gases and radioactive material 
(Room 1117). 
DTF-WREMLDEV-R1 Normal Operations The sampling operation is conducted so that exposure of workers to radiation is 
managed as a normal-operations dose by procedures for monitoring radiation doses and 
assigning work, which ensure that workers do not receive excessive radiation doses. 
Although a rupture leading to a radiological release would be an off-normal occurrence, 
any release and related dose would be managed as part of routine radiation protection 
operations. 
Mitigative Procedural 
Safety 
2. Uncontrolled pool water draindown/fill or leak of pool cooling or 
water treatment system resulting in flooding and radioactive 
contamination of adjoining areas (Room 1117). 
DTF-WREMLDEV-R2 Normal Operations Same disposition as Potential Event DTF-WREMLDEV-CCF1. Additionally, operational 
requirements maintain water quality within prescribed limits to ensure radiological doses 
are as low as reasonably achievable in areas around the pools; and the disposition of 
leaking water is controlled. Pool operations are conducted so that exposure of workers 
to radiation is managed as a normal-operations dose by procedures for monitoring 
radiation doses and assigning work, which ensure that workers do not receive excessive 
radiation doses. 
Preventive Design- 
Procedural 
Safety 
3. Increased radiation levels in the pool cell due to low pool water 
level uncovering SNF assemblies (either in an opened cask or 
MSC or in the SNF basket staging rack) (Room 1117). 
DTF-WREMLDEV-R3 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CCF1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-108 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
4. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1117 and 1120). 
DTF-WREMLDEV-R4 NAAccounted for in 
consequence 
analyses, if 
applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for all the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. 
Exposures are managed by design features and procedures that ensure that workers or 
the public do not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
5. Loss of confinement zone due to a ventilation system malfunction 
or other breach of a confinement barrier leading to a release of 
radiation (Room 1117). 
DTF-WREMLDEV-R5 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of 
radioactivity. 
Mitigative Procedural 
Safety 
6. Insufficient cooling of a cask or loss of the cask cooling system 
prior to lowering of a cask into the pool, leading to a release of 
radiologically contaminated steam or gasses (Room 1117). 
DTF-WREMLDEV-R6 Normal Operations Pool operations are conducted so that any potential exposure of workers to radiation is 
managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
7. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Room 
1117). 
DTF-WREMLDEV-R7 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting exposure of workers to radiation is managed as a normal-operations dose 
by procedures for monitoring radiation doses and assigning work, which ensure that 
workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
8. Radiation-induced damage to a facility SSC (Rooms 1117 and 
1120). 
DTF-WREMLDEV-R8 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a derailment of a trolley moving a 
loaded cask or MSC followed by a load tipover or fall and a 
rearrangement of the container internals (Room 1117). 
DTF-WREMLDEV-F1 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC3. Preventive Design 
2. Criticality associated with a derailment of an SRTC holding a 
loaded cask or MSC followed by a load tipover or fall and a 
rearrangement of the container internals (Rooms 1117 and 1120). 
DTF-WREMLDEV-F2 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-CC4. Preventive Design 
3. Criticality associated with a drop, slapdown, or collision of a cask 
or a MSC (when handled with an overhead crane) and a 
rearrangement of the container internals (Room 1117). 
DTF-WREMLDEV-F3 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, CSNF baskets used in dry processing areas, and dual-purpose 
canisters (DPCs) are designed to ensure nuclear criticality safety with optimum 
moderation and most-reactive waste forms. Criticality safety will be maintained despite 
geometric rearrangements due to a drop or other handling incident. 
Preventive Design 
4. Criticality associated with a drop of an SNF assembly while 
unloading a transportation cask, loading cask or MSC, or filling or 
emptying an SNF basket in the pool, and a rearrangement of SNF 
in the cask, MSC, or basket (Room 1117). 
DTF-WREMLDEV-F4 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-F3. Additionally, design and 
operational requirements ensure criticality safety in the baskets and baskets in the 
storage rack. Fully loaded baskets in staging racks are designed to be subcritical when 
fully flooded with pure water (i.e., no credit for neutron absorbers dissolved in the water). 
Baskets are designed to have sufficient nuclear criticality controls to remain subcritical 
even if a handling incident causes a reconfiguration of the spent fuel. Baskets are closed 
during handling. A closed basket being transferred in the pool would not spill SNF 
assemblies into the pool if the basket is dropped. 
Preventive Design 
5. Criticality associated with a drop of an SNF assembly from the 
fuel handling machine (in the pool) and a rearrangement of the 
fuel rods that comprise the assembly due to impact (Room 1117). 
DTF-WREMLDEV-F5 NA Results of criticality analyses ensure that drops, collisions, and other handling impacts of 
a commercial SNF assembly, allowing for rearrangement of fuel rods and without credit 
for burnup or moderator control, do not pose a criticality safety concern. 
NA NA 
6. Criticality associated with a misload of a cask or MSC in the pool 
(Room 1117). 
DTF-WREMLDEV-F6 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-F3. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-109 April 2005 
Table III-21. Disposition of Internal Events That Occur Inside the Dry Transfer Facility (Wet Remediation): Cask Wet Remediation-Laydown Area (Room 1117), Cask Wet Remediation Entrance Vestibule (Room 1120) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
7. Criticality associated with a misload of an SNF basket or SNF 
baskets in the basket storage rack (Room 1117). 
DTF-WREMLDEV-F7 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-F4. Preventive Design 
8. Criticality associated with the drop of a spent fuel assembly 
basket holding several SNF assemblies in the pool (including a 
drop onto another basket) and a rearrangement of the contents of 
the basket or baskets (Room 1117). 
DTF-WREMLDEV-F8 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-F4. Preventive Design 
9. Criticality associated with the drop of heavy equipment onto a 
loaded fuel basket (either a single basket or several baskets in a 
basket storage rack) and a rearrangement of the contents of the 
basket or baskets (Room 1117). 
DTF-WREMLDEV-F9 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-F4. Preventive Design 
10. Criticality associated with the drop of heavy equipment onto a 
loaded cask or MSC and a rearrangement of the container 
internals (either in or out of the pool) (Room 1117). 
DTF-WREMLDEV-F10 Beyond Category 2 Same disposition as Potential Event DTF-WREMLDEV-F3. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; EI = explosion-implosion; F = fissile; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail 
transfer cart; WREMLDEV = wet remediation-laydown and entrance vestibule. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example WREMLDEV, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column. The GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-110 April 2005 
Table III-22. Disposition of Internal Events That Occur Inside the Dry Transfer Facility Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 1100), Dual-purpose Canister Docking Room (Room 1101), and Dual-purpose 
Canister Cutting/Waste Package Dry Remediation Cell (Room 1097) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the trolley holding the cask containing the 
loaded DPC and the shield doors between the cask preparation 
room and the DPC preparation/cask dry remediation room 
(Rooms 1074 and 1100). 
DTF-DPCPRM-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. Shield doors between the cask preparation room and the DPC 
preparation/cask dry remediation room close on the trolley holding 
the cask containing the loaded DPC (Rooms 1074 and 1100). 
DTF-DPCPRM-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of a trolley in the DPC preparation/cask dry 
remediation room or DPC docking room (including derailment due 
to turntable malfunction or operational error) while holding a cask 
containing a loaded DPC followed by a load tipover or fall (Rooms 
1101 and 1109). 
DTF-DPCPRM-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, 
and dual-purpose canisters. 
Preventive Design 
4. Drop or collision of a docking ring (or tools, or equipment) onto or 
against the cask containing the DPC (Room 1101). 
DTF-DPCPRM-CC4 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, can not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
5. Collision involving the docking ring station or other access 
platforms and a cask containing a loaded DPC in the DPC 
preparation/cask dry remediation room (Room 1100). 
DTF-DPCPRM-CC5 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
6. Collision involving a trolley holding the cask containing the loaded 
DPC and the shield doors between DPC preparation/cask dry 
remediation room and the DPC docking room (Rooms 1100 and 
1101). 
DTF-DPCPRM-CC6 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-DPCPRM-CC1. Preventive Design 
7. Shield doors between the DPC preparation/cask dry remediation 
room and the DPC docking room close on a trolley holding the 
cask containing the loaded DPC (Rooms 1100 and 1101). 
DTF-DPCPRM-CC7 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-CC2. Preventive Design 
8. Derailment of a trolley holding the cask containing the loaded 
DPC on the turntable in the DPC docking room followed by a load 
tipover or fall (Room 1101). 
DTF-DPCPRM-CC8 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-CC3. Preventive Design 
9. Collision of a trolley holding the cask containing the loaded DPC 
with another trolley holding a cask on the turntable in the DPC 
docking room (Room 1101). 
DTF-DPCPRM-CC9 Beyond Category 2 (See GET-22) Same disposition as Potential Event DTF-DPCPRM-CC1. Preventive Design 
10.Drop or collision of a docking port (mobile slab) onto or against a 
cask containing the loaded DPC (Room 1101). 
DTF-DPCPRM-CC10 Beyond Category 2 A design requirement ensures that a drop of or collision involving components associated 
with a docking port will not breach the lid of a cask or MSC situated at the docking port. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-111 April 2005 
Table III-22. Disposition of Internal Events That Occur Inside the Dry Transfer Facility Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 1100), Dual-purpose Canister Docking Room (Room 1101), and Dual-purpose Canister 
Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
11.Drop or collision of a docking port plug onto or against the lid of a 
cask containing the loaded DPC (with outer lid removed [if 
applicable] and inner lid unbolted but in place) ((Room 1101). 
DTF-DPCPRM-CC11 Beyond Category 2 Design requirements ensure that portions of a non-ITS SSC which, upon failure, could 
adversely interact with an ITS SSC and prevent its safety function from being performed 
are classified as ITS, redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC, or, for seismic interactions, designed to the same seismic DBGM as 
the ITS SSCs subjected to the potential unacceptable interaction. 
Preventive Design 
12. Drop of an inner lid on a cask containing the loaded DPC (with 
outer lid removed [if applicable]) (Room 1101). 
DTF-DPCPRM-CC12A 
DTF-DPCPRM-CC12B 
No drop 
Category 2 
(See GET-02 Sequences A and B only) Design and operational requirements reduce the 
drop probability. 
Preventive Design- 
Procedural 
Safety 
13.Drop or collision of DPC handling device or tools or equipment 
onto or against the DPC during the drilling/installation of the DPC 
handling device (Room 1101). 
DTF-DPCPRM-CC13 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-CC4. Preventive Procedural 
Safety 
14.Drop or collision of a loaded DPC from the DPC Cutting/WP Dry 
Remediation Cell overhead crane through the unload port back 
into or against the cask being unloaded during the DPC transfer 
from the cask to the DPC cutting/WP dry remediation cell cutting 
machine base (Room 1097). 
DTF-DPCPRM-CC14A 
DTF-DPCPRM-CC14B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. For collisions, a design requirement limits speed for crane transfers such 
that a collision at the maximum speed could not breach an MSC, transportation cask, 
transfer cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
15.Drop of a loaded DPC from the DPC Cutting/WP Dry Remediation 
Cell overhead crane onto the DPC cutting/WP dry remediation cell 
floor during DPC transfer from the cask to the DPC cutting/WP dry 
remediation cell cutting machine base (Room 1097). 
DTF-DPCPRM-CC15A 
DTF-DPCPRM-CC15B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTFDPCPRM-
CC14. 
Preventive Design- 
Procedural 
Safety 
16.Drop of a loaded DPC from the DPC Cutting/WP Dry Remediation 
Cell overhead crane onto the cutting machine base during DPC 
transfer from the cask to the DPC cutting/WP dry remediation cell 
cutting machine base (Room 1097). 
DTF-DPCPRM-CC16A 
DTF-DPCPRM-CC16B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTFDPCPRM-
CC14. 
Preventive Design- 
Procedural 
Safety 
17.Drop or collision of a loaded DPC from the DPC Cutting/WP Dry 
Remediation Cell overhead crane onto or against a sharp object 
during DPC transfer from the cask to the DPC cutting/WP dry 
remediation cell cutting machine base (Room 1097). 
DTF-DPCPRM-CC17A 
DTF-DPCPRM-CC17B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTFDPCPRM-
CC14. 
Preventive Design- 
Procedural 
Safety 
18.Drop or collision of the lid-cutting machine onto or against the 
DPC during the lowering of the machine for the lid-cutting 
operation (Room 1097). 
DTF-DPCPRM-CC18 Beyond Category 2 A design requirement ensure that the mass, potential drop height, and other characteristics 
of the canister cutting machine are such that the dual-purpose canister lid prevents 
damage to the commercial SNF resulting in a potential radiological release should the 
cutting machine fall onto or make contact with the dual-purpose canister. 
Preventive Design 
19.Damage to one or more fuel assembly(ies) during lid-cutting 
operations or the DPC drainpipe cutting operation (Room 1097). 
DTF-DPCPRM-CC19 Beyond Category 2 A design requirement ensures that the canister cutting machine is designed to preclude a 
radiological release due to damage inflicted upon the DPC contents during the cutting 
process. 
Preventive Design 
20.Drop or collision of the DPC cutting machine onto or against the 
open (lidless) DPC during the removal of the machine after the lidcutting 
operation (Room 1097). 
DTF-DPCPRM-CC20 Beyond Category 2 An operational requirement ensures that the canister cutting machine is not suspended 
over the open dual-purpose canister after the lid is removed. 
Preventive Procedural 
Safety 
21.Drop or collision of the severed lid back onto or against the open 
DPC from the ceiling-mounted manipulator or overhead crane 
after the completion of the DPC lid-cutting (Room 1097). 
DTF-DPCPRM-CC21A 
DTF-DPCPRM-CC21B 
No drop 
Category 2 
(See GET-20) Design and operational requirements reduce the drop probability for cranes 
involved in handling waste forms and their associated containers.. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-112 April 2005 
Table III-22. Disposition of Internal Events That Occur Inside the Dry Transfer Facility Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 1100), Dual-purpose Canister Docking Room (Room 1101), and Dual-purpose Canister 
Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
22.Drop or collision of handling equipment (lid grapple, etc.) onto or 
against the unsealed (open) loaded DPC (Room 1097). 
DTF-DPCPRM-CC22A 
DTF-DPCPRM-CC22B 
No drop 
Category 2 
An operational requirement prohibits suspending a lid grapple above an open dual-purpose 
canister unless the lid is in place or is being lifted. 
If the lid is in place, then a design requirement ensures that a drop of handling equipment 
onto a dual-purpose canister with its severed lid in place does not initiate an event 
sequence. 
If the lid is being lifted, the potential event is analyzed as a lid-drop event. (see GET-20) 
Same disposition as Potential Event DTF-DPCPRM-CC21. 
Preventive Design- 
Procedural 
Safety 
23. Drop of an unsealed (open), loaded DPC from the overhead 
crane in the DPC cutting/WP dry remediation cell onto the floor 
during the transfer of the DPC from the DPC cutting machine base 
to the trolley that travels to the unloading port to the waste transfer 
cell (Room 1097). 
DTF-DPCPRM-CC23A 
DTF-DPCPRM-CC23B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTFDPCPRM-
CC14. 
Preventive Design- 
Procedural 
Safety 
24.Drop of an unsealed (open), loaded DPC from the overhead crane 
in the DPC cutting/WP dry remediation cell onto the trolley during 
the transfer of the DPC from the DPC cutting machine base to the 
trolley that travels to the unloading port to the waste transfer cell 
(Room 1097). 
DTF-DPCPRM-CC24A 
DTF-DPCPRM-CC24B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTFDPCPRM-
CC14. 
Preventive Design- 
Procedural 
Safety 
25.Drop or collision of an unsealed (open), loaded DPC from the 
overhead crane in the DPC cutting/WP dry remediation cell onto 
or against a sharp object during the transfer of the DPC from the 
DPC cutting machine base to the trolley that travels to the 
unloading port to the waste transfer cell (Room 1097). 
DTF-DPCPRM-CC25 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
26.Slapdown of an unsealed (open), loaded DPC following a drop 
from the overhead crane in the DPC cutting/WP dry remediation 
cell onto the edge of a trolley that travels to the unloading port to 
the waste transfer cell during the lift and transfer to the trolley 
(Room 1097). 
DTF-DPCPRM-CC26A 
DTF-DPCPRM-CC26B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event DTFDPCPRM-
CC14. 
Preventive Design- 
Procedural 
Safety 
27.Derailment of a trolley (that travels to the unloading port to the 
waste transfer cell) holding a loaded DPC (in an unsealed, 
opened state) in the DPC cutting/WP dry remediation cell, 
followed by a load tipover or fall (Room 1097). 
DTF-DPCPRM-CC27 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-CC3. Preventive Design 
28.Drop or collision of a SNF assembly from the spent fuel transfer 
machine back into or against the DPC being unloaded 
(Room 1097). 
DTF- DPCPRM-CC28A 
DTF- DPCPRM-CC28B 
DTF- DPCPRM-CC28C 
DTF- DPCPRM-CC28D 
DTF- DPCPRM-CC28E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Design and operational requirements for the spent fuel transfer machine (in 
the dry transfer areas) and fuel handling machine (in the pool) reduce the drop rate and 
collision probabilities for commercial SNF assembly transfers, including those in singleassembly 
canisters. Assemblies are assumed to breach when they are dropped or 
involved in a collision. HVAC system reliability requirements ensure availability of highefficiency 
particulate air filtration in the primary confinement areas of the DTF and FHF 
during a 4-h mission time without credit for backup electrical power. An operational 
requirement ensures that HVAC system is working properly before normal operations 
begin, that the HVAC system is monitored for proper operation during normal operations, 
and that normal operations are suspended if the HVAC system or offsite power becomes 
unavailable. 
Preventive- 
Mitigative 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-113 April 2005 
Table III-22. Disposition of Internal Events That Occur Inside the Dry Transfer Facility Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 1100), Dual-purpose Canister Docking Room (Room 1101), and Dual-purpose Canister 
Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
29.Drop or collision of a SNF assembly from the spent fuel transfer 
machine onto or against another SNF assembly or assemblies in 
the DPC being unloaded (Room 1097). 
DTF- DPCPRM-CC29A 
DTF- DPCPRM-CC29B 
DTF- DPCPRM-CC29C 
DTF- DPCPRM-CC29D 
DTF- DPCPRM-CC29E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DTF-DPCPRM-CC28. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
30.Impact due to horizontal movement of a SNF assembly by the 
spent fuel transfer machine before the assembly is fully lifted out 
of the DPC (Room 2048). 
DTF- DPCPRM-CC30A 
DTF- DPCPRM-CC30B 
DTF- DPCPRM-CC30C 
DTF- DPCPRM-CC30D 
DTF- DPCPRM-CC30E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DTF-DPCPRM-CC28. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
31.Drop or collision of a SNF assembly from the spent fuel transfer 
machine onto or against a sharp object (other than another SNF 
assembly) (Room 2048). 
DTF-DPCPRM-CC31 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-CC25. Preventive Design- 
Procedural 
Safety 
32.Drop and slapdown of an SNF assembly from the spent fuel 
transfer machine (due to impact with an edge of the DPC, the floor 
edge, a DPC internal baffle, etc.) during the SNF transfer from the 
DPC to a WP or staging rack (Room 2048). 
DTF- DPCPRM-CC32A 
DTF- DPCPRM-CC32B 
DTF- DPCPRM-CC32C 
DTF- DPCPRM-CC32D 
DTF- DPCPRM-CC32E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event DTF-DPCPRM-CC28. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperature (Rooms 1100, 1101, 1097, 
and 2048). 
DTF-DPCPRM-CCF1 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a cask-handling trolley 
(Rooms 1100, 1101, and 1097). 
DTF-DPCPRM-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the sampling and purging 
system or the cutting and removal of the DPC enclosure lid 
system and the ignition of hydrogen that may have accumulated in 
the canister (Room 1100). 
DTF-DPCPRM-EI2 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventive Procedural 
Safety 
3. DPC sampling and purging system (or other pneumatic or 
pressurized system) missile due to a fractured nozzle/valve 
stem/pneumatic device (Room 1100). 
DTF-DPCPRM-EI3 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with SNF handling equipment in the DPC 
preparation/dry remediation room, DPC docking room, the waste 
transfer cell, or the DPC cutting/WP dry remediation cell (including 
the overhead cranes, manipulators, the chipless cutting 
equipment, etc.) (Rooms 1100, 1101, 1097, and 2048). 
DTF-DPCPRM-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) associated with the caskhandling 
trolley (Rooms 1100, 1101, and 1097). 
DTF-DPCPRM-FT2 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-FT1. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-114 April 2005 
Table III-22. Disposition of Internal Events That Occur Inside the Dry Transfer Facility Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 1100), Dual-purpose Canister Docking Room (Room 1101), and Dual-purpose Canister 
Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Electrical fire associated with the trolley in the DPC cutting/WP dry 
remediation cell. (Room 1097). 
DTF-DPCPRM-FT3 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-FT1. Preventive Design- 
Procedural 
Safety 
4. Intact or non-intact SNF overheating due to a loss of cooling 
resulting in excessive temperature and possible zircaloy cladding 
(or other cladding) unzipping or cladding failure due to excessive 
hoop stresses (Rooms 1100, 1101, 1097, and 2048). 
DTF-DPCPRM-FT4 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
5. Thermal hazard (from decay heat) associated with vertical 
orientation of the cask holding the DPC (Rooms 1100, 1101, and 
1097). 
DTF-DPCPRM-FT5 Normal Operations Same disposition as Potential Event DTF-DPCPRM-CCF1 Mitigative Procedural 
Safety 
6. Transient combustible fire in the DPC preparation/dry remediation 
room, DPC docking room, the waste transfer cell, or the DPC 
cutting/WP dry remediation cell (Rooms 1100, 1101, 1097, and 
2048). 
DTF-DPCPRM-FT6 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1100, 1101, 1097, and 2048). 
DTF-DPCPRM-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Damage or rupture of the DPC sampling and purging system, 
leading to a release of canister internal gases and radioactive 
material (Room 1100). 
DTF-DPCPRM-R2 Normal Operations The sampling operation is conducted so that exposure of workers to radiation is managed 
as a normal-operations dose by procedures for monitoring radiation doses and assigning 
work, which ensure that workers do not receive excessive radiation doses. Although a 
rupture leading to a radiological release would be an off-normal occurrence, any release 
and related dose would be managed as part of routine radiation protection operations. 
Mitigative Procedural 
Safety 
3. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1100, 1101, 1097, and 2048). 
DTF-DPCPRM-R3 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
4. Thermal expansion of gases or other loss of confinement in an 
unsealed cask, leading to radiological release (Rooms 1101, 
1097, and 2048). 
DTF-DPCPRM-R4 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1100, 1101, 
1097, and 2048). 
DTF-DPCPRM-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a derailment of a trolley moving a 
transportation cask holding a sealed, loaded DPC and a 
rearrangement of the DPC contents followed by a load tipover or 
fall (Rooms 1100, 1101, and 1097). 
DTF-DPCPRM-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-115 April 2005 
Table III-22. Disposition of Internal Events That Occur Inside the Dry Transfer Facility Dual-purpose Canister Preparation-Cask Dry Remediation Room (Room 1100), Dual-purpose Canister Docking Room (Room 1101), and Dual-purpose Canister 
Cutting/Waste Package Dry Remediation Cell (Room 1097) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Criticality associated with a drop or slapdown of a sealed, loaded 
DPC from the DPC Cutting/WP Dry Remediation Cell overhead 
crane and a rearrangement of the DPC contents (Room 1097). 
DTF-DPCPRM-F2 Beyond Category 2 Same disposition as Potential Event DTF- DPCPRM-F1. Additionally, a design 
requirement ensures that dropping a DOE SNF canister within its design basis does not 
lead to a criticality. Demonstration of compliance for the staging rack must account for the 
most reactive configuration of DOE SNF canisters with credit for moderator control. Design 
and operational requirements ensure that moderator control is in effect. There is no 
potential for criticality of DOE HLW canisters. Criticality of a naval canister following a drop, 
or other impact event, has been evaluated to be Beyond Category 2 based upon 
probabilities of independent events required for criticality. 
Preventive Design 
3. Criticality associated with a drop or slapdown of an unsealed 
(open) loaded, or sealed (unopened) loaded DPC from DPC 
cutting area overhead crane and a rearrangement of the DPC 
contents (Room 1097). 
DTF-DPCPRM-F3 Beyond Category 2 Same disposition as Potential Event DTF- DPCPRM-F1. Preventive Design 
4. Criticality associated with a derailment of a trolley moving an 
unsealed (open) loaded DPC followed by a load tipover or fall and 
a rearrangement of the DPC contents (Rooms 1101 and 1097). 
DTF-DPCPRM-F4 Beyond Category 2 Same disposition as Potential Event DTF- DPCPRM-CC3. Preventive Design 
5. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine back into the DPC being unloaded 
and a rearrangement of the canister internals (Room 2048). 
DTF-DPCPRM-F5 Beyond Category 2 Same disposition as Potential Event DTF- DPCPRM-F1. Preventive Design 
6. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine and a rearrangement of the fuel rods 
that comprise the assembly due to impact (Room 2048). 
DTF-DPCPRM-F6 NA Results of criticality analyses ensure that drops, collisions, and other handling impacts of a 
commercial SNF assembly (allowing for rearrangement of fuel rods and without credit for 
burnup or moderator control) do not pose a criticality safety concern. 
NA NA 
7. Criticality associated with the drop of heavy equipment onto an 
unsealed (open) loaded, or sealed (unopened) loaded DPC and a 
rearrangement of the container internals (Rooms 1101 and 1097). 
DTF-DPCPRM-F7 Beyond Category 2 Same disposition as Potential Event DTF-DPCPRM-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical contamination flooding; DBGM = design basis ground motion; DPCPRM= dual purpose canister preparation remediation room; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FT = fire-thermal; 
GET = generalized event tree; HLW = high-level radioactive waste; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example DTF, the middle identifies an activity, room, or area, for example DPCPRM, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
Additional room(s) with potential events in this table: Room 1074 - Cask preparation room; Room 1109 - cask docking/dry remediation room; Room 2048 - Waste transfer cell. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-116 April 2005 
Table III-23. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Cask and Site-specific Cask Receipt): Entrance Vestibule (Room 1001) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category 
Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Railcar derailment, overturning, or collision involving a loaded 
cask followed by a load tipover or fall (Room 1001). 
FHF-EV-CC1 Beyond Category 2 Transportation casks with impact limiters are designed to withstand, without breaching, 
the bounding drops that could occur during cask handling at the repository. Consequently, 
a derailment, overturning or collision would not breach a transportation cask. 
Preventive Design 
2. Overturning or collision involving an LWT or an OWT holding a 
loaded cask (with impact limiters and personnel barrier installed) 
(Room 1001). 
FHF-EV-CC2 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC1. Preventive Design 
3. Collision of a railcar, an LWT, or OWT carrying a loaded cask 
(with impact limiters and personnel barrier installed) with the 
entrance vestibule doors (Room 1001). 
FHF-EV-CC3 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC1. Preventive Design 
4. The entrance vestibule doors close on a railcar, an LWT, or an 
OWT carrying a loaded cask (with impact limiters and personnel 
barrier installed) (Room 1001). 
FHF-EV-CC4 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC1. Preventive Design 
5. Collision of the gantry crane carrying a loaded MSC with the 
entrance vestibule doors (Room 1001). 
FHF-EV-CC5 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
6. The entrance vestibule doors close on the entrance vestibule 
gantry crane carrying a loaded MSC (Room 1001). 
FHF-EV-CC6 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
7. Collision of a mobile elevated platform with a loaded cask or the 
conveyance holding the cask during removal of personnel 
barriers and impact limiters or during survey activities 
(Room 1001). 
FHF-EV-CC7 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
8. Drop or collision of personnel barriers or impact limiters from the 
entrance vestibule gantry crane onto or against the loaded cask 
(Room 1001). 
FHF-EV-CC8 Beyond Category 2 Operational requirements for cask preparation and handling ensure that a drop of or 
collision involving equipment would not breach a transportation cask, transfer cask, or an 
MSC. 
Preventive Procedural 
Safety 
9. Collision between a forklift and a loaded cask on a railcar, an 
LWT, an OWT, or the conveyance holding the cask, prior to or 
after the removal of impact limiters and personnel barrier 
(Room 1001). 
FHF-EV-CC9 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC7. Preventive Procedural 
Safety 
10. Collision between a mobile elevating platform and a loaded cask 
on a railcar, an LWT, an OWT, or the conveyance holding the 
cask (Room 1001). 
FHF-EV-CC10 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC1. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-117 April 2005 
Table III-23. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Cask and Site-specific Cask Receipt): Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category 
Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
11. Collision between the entrance vestibule gantry crane carrying a 
loaded MSC and a forklift. (Room 1001). 
FHF-EV-CC11 Beyond Category 2 Same disposition as Potential Events FHF-EV-CC5 and FHF-EV-CC7. Preventive Design- 
Procedural 
Safety 
12. Collision between the entrance vestibule gantry crane carrying 
the loaded MSC and a mobile elevated platform (Room 1001). 
FHF-EV-CC12 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC11. Preventive Design- 
Procedural 
Safety 
13. Drop or collision of equipment from the entrance vestibule gantry 
crane (including handling equipment for personnel barriers, 
impact limiters, etc.) onto or against a loaded cask or loaded 
MSC. (Room 1001). 
FHF-EV-CC13 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC8. Preventive Procedural 
Safety 
14. Slapdown of a loaded cask onto a railcar, a truck trailer, or the 
floor during upending of the cask to the vertical orientation (after 
removal of the impact limiters and personnel barrier) 
(Room 1001). 
FHF-EV-CC14A 
FHF-EV-CC14B 
FHF-EV-CC14C 
FHF-EV-CC14D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact limiters 
and site-specific casks. Design and operational requirements limit the probability of 
exceeding the lift height. A design requirement limits speed for crane transfers such that a 
collision at the maximum speed could not breach an MSC, transportation cask, transfer 
cask, DPC, DOE or naval canister, or waste package involved in the transfer. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
15. Drop of a loaded cask in a horizontal position (such as the Hi 
Star) from the entrance vestibule gantry crane onto the floor or 
back onto the railcar or truck trailer during the transfer from a 
railcar or truck trailer to the tilting frame (Room 1001). 
FHF-EV-CC15A 
FHF-EV-CC15B 
FHF-EV-CC15C 
FHF-EV-CC15D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
16. Drop or collision of a loaded cask in a horizontal position (such 
as the Hi Star) from the entrance vestibule gantry crane onto or 
against a sharp object or the tilting frame during the transfer from 
a railcar or truck trailer to the tilting frame (Room 1001). 
FHF-EV-CC16 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventative Design- 
Procedural 
Safety 
17. Drop of a loaded cask from the entrance vestibule gantry crane 
onto the floor during the transfer from a railcar, truck trailer, or 
tilting frame to the pedestal on an import-export trolley 
(Room 1001). 
FHF-EV-CC17A 
FHF-EV-CC17B 
FHF-EV-CC17C 
FHF-EV-CC17D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
18. Drop of a loaded cask from the entrance vestibule gantry crane 
onto the pedestal on an import-export trolley during the transfer 
from a railcar, truck trailer, or tilting frame to the pedestal on an 
import-export trolley (Room 1001). 
FHF-EV-CC18A 
FHF-EV-CC18B 
FHF-EV-CC18C 
FHF-EV-CC18D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
19. Drop or collision of a loaded cask from the entrance vestibule 
gantry crane onto or against a sharp object during the transfer 
from a railcar, truck trailer, or tilting frame to the pedestal on an 
import-export trolley (Room 1001). 
FHF-EV-CC19 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC16. Preventative Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-118 April 2005 
Table III-23. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Cask and Site-specific Cask Receipt): Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category 
Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
20. Drop of a loaded MSC from the entrance vestibule gantry crane 
onto the floor during the transfer from the FHF pad to the 
pedestal on an import-export trolley (Room 1001). 
FHF-EV-CC20A 
FHF-EV-CC20B 
FHF-EV-CC20C 
FHF-EV-CC20D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
21. Drop of a loaded MSC from the entrance vestibule gantry crane 
onto the pedestal on an import-export trolley during the transfer 
from the FHF pad to the pedestal on an import-export trolley 
(Room 1001). 
FHF-EV-CC21A 
FHF-EV-CC21B 
FHF-EV-CC21C 
FHF-EV-CC21D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
22. Drop or collision of a loaded MSC from the entrance vestibule 
gantry crane onto or against a sharp object during the transfer 
from the FHF pad to the pedestal on an import-export trolley 
(Room 1001). 
FHF-EV-CC22 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC16. Preventative Design- 
Procedural 
Safety 
23. Slapdown of a loaded cask in the entrance vestibule due to offcenter 
cask lowering or drop onto the pedestal on an importexport 
trolley (Room 1001). 
FHF-EV-CC23A 
FHF-EV-CC23B 
FHF-EV-CC23C 
FHF-EV-CC23D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
24. Slapdown of a loaded MSC in the entrance vestibule due to offcenter 
MSC lowering or drop onto the pedestal or edge of the 
pedestal on an import-export trolley (Room 1001). 
FHF-EV-CC24A 
FHF-EV-CC24B 
FHF-EV-CC24C 
FHF-EV-CC24D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-01) Same disposition as Potential Event FHF-EV-CC14. Preventive Design- 
Procedural 
Safety 
25. Handling equipment drop onto a loaded cask or loaded MSC 
(Room 1001). 
FHF-EV-CC25 Beyond Category 2 Same disposition as Potential Event FHF-EV-CC8. Preventive Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures or during off-normal temperatures 
(e.g., during a failure of the cooling system) (Room 1001). 
FHF-EV-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed cask, therefore this event does not occur unless an 
event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible 
outcome of any event that exposes SNF to air. Consequence analyses account for the 
possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a forklift (Room 1001). FHF-EV-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-119 April 2005 
Table III-23. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Cask and Site-specific Cask Receipt): Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category 
Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1001). 
FHF-EV-EI2 Beyond Category 2 Same disposition as Potential Event FHF-EV-EI1. Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on the import-export 
trolley (Room 1001). 
FHF-EV-EI3 Beyond Category 2 Same disposition as Potential Event FHF-EV-EI1. Preventive Procedural 
Safety 
4. Hydrogen explosion involving batteries on a site prime mover 
(Room 1001). 
FHF-EV-EI4 Beyond Category 2 Same disposition as Potential Event FHF-EV-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the entrance vestibule gantry crane 
(Room 1001). 
FHF-EV-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
entrance vestibule electrical equipment (Room 1001). 
FHF-EV-FT2 Beyond Category 2 Same disposition as Potential Event FHF-EV-FT1. Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) involving a site prime mover 
pulling or pushing a conveyance holding a loaded cask 
(Room 1001). 
FHF-EV-FT3 Beyond Category 2 Same disposition as Potential Event FHF-EV-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) associated with the importexport 
trolley (Room 1001). 
FHF-EV-FT4 Beyond Category 2 Same disposition as Potential Event FHF-EV-FT1. Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with a forklift 
(Room 1001). 
FHF-EV-FT5 Beyond Category 2 Same disposition as Potential Event FHF-EV-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with the mobile 
elevated platform (Room 1001). 
FHF-EV-FT6 Beyond Category 2 Same disposition as Potential Event FHF-EV-FT1. Preventive Design- 
Procedural 
Safety 
7. Thermal hazard (from decay heat) associated with vertical 
orientation of a loaded cask (Room 1001). 
FHF-EV-FT7 Beyond Category 2 Transportation casks are designed to withstand normal conditions of transport (including 
high ambient temperatures and insolation) and hypothetical accident conditions (including 
fire). These conditions bound the thermal effect of orienting the cask vertically rather than 
horizontally. This potential event would not cause oxidation of SNF leading to exposure of 
individuals to radiation because the waste is contained in a sealed cask. 
Preventive Design 
8. Transient combustible fire in the entrance vestibule 
(Room 1001). 
FHF-EV-FT8 Beyond Category 2 Same disposition as Potential Event FHF-EV-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1001). 
FHF-EV-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction 
or other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1001). 
FHF-EV-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-120 April 2005 
Table III-23. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Cask and Site-specific Cask Receipt): Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category 
Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Radiation-induced damage to a facility SSC (Room 1001). FHF-EV-R3 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a railcar (holding a loaded cask ) 
derailment or collision followed by a load tipover or fall and 
rearrangement of the cask internals (Room 1001). 
FHF-EV-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with an overturning or collision involving an 
LWT or an OWT holding a loaded cask and rearrangement of 
cask internals (Room 1001). 
FHF-EV-F2 Beyond Category 2 Same disposition as Potential Event FHF-EV-F1. Preventive Design 
3. Criticality associated with a drop or slapdown of a cask and a 
rearrangement of the container internals (Room 1001). 
FHF-EV-F3 Beyond Category 2 Same disposition as Potential Event FHF-EV-F1. Preventive Design 
4. Criticality associated with a drop or slapdown of an MSC and a 
rearrangement of the container internals (Room 1001). 
FHF-EV-F4 Beyond Category 2 Same disposition as Potential Event FHF-EV-F1. Preventive Design 
5. Criticality associated with collision of the entrance vestibule 
gantry crane holding an MSC followed by a load drop or tipover 
and a rearrangement of the MSC internals (Room 1001). 
FHF-EV-F5 Beyond Category 2 Same disposition as Potential Event FHF-EV-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; EI = explosion-implosion; EV = entrance vestibule; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = generalized event tree; LWT = legal-weight truck; NA = not applicable; OWT = 
overweight truck; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF, the middle identifies an activity, room, or area, for example EV, and the suffix identifies the hazard category and 
event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-121 April 2005 
Table III-24. Disposition of Internal Events That Occur Inside the Fuel Handling Facility: Preparation Room (Room 1002) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision of a loaded cask or loaded MSC on a pedestal on the 
import-export trolley with the preparation room shield doors 
separating the FHF entrance vestibule from the preparation room 
(Room 1002). 
FHF-PR-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. The preparation room shield doors separating the FHF entrance 
vestibule from the preparation room close on a loaded cask or 
loaded MSC on a pedestal on the import-export trolley (Room 
1002). 
FHF-PR-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
3. Derailment of an import-export trolley holding a loaded cask or 
loaded MSC on a pedestal (with outer and/or inner lid bolted in 
place, if applicable) followed by a load tipover or fall (Room 1002). 
FHF-PR-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
4. Drop or collision of tools or equipment (including a lid-lifting 
fixture, lid bolts, etc.) onto or against a loaded cask or loaded 
MSC outer lid (if applicable) or a cask or MSC inner lid in the 
preparation room (Room 1002). 
FHF-PR-CC4 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, can not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
5. Collision of a mobile elevated platform with a loaded cask or 
loaded MSC during preparation activities on top of the cask or 
MSC (Room 1002). 
FHF-PR-CC5 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, mobile 
elevated platforms, and forklifts operated in the facility are not operated in a manner that 
could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
6. Drop of a cask or MSC outer lid onto the loaded cask or loaded 
MSC (if applicable) in the preparation room (Room 1002). 
FHF-PR-CC6A 
FHF-PR-CC6B 
FHF-PR-CC6C 
FHF-PR-CC6D 
FHF-PR-CC6E 
FHF-PR-CC6F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
7. Derailment of an import-export trolley holding a loaded cask or 
loaded MSC on a pedestal (with outer lid removed [if applicable] 
and inner lid unbolted but in place) followed by a load tipover or 
fall (Room 1002). 
FHF-PR-CC7 Beyond Category 2 Same disposition as Potential Event FHF-PR-CC3. Preventive Design 
8. Collision of an import-export trolley holding a loaded cask or 
loaded MSC on a pedestal (with outer lid removed [if applicable] 
and inner lid unbolted but in place) with shield doors separating 
the preparation room and the main transfer room (Room 1002). 
FHF-PR-CC8 Beyond Category 2 (See GET-22) Same disposition as Potential Event FHF-PR-CC1. Preventive Design 
9. Closure of the shield doors separating the preparation room and 
the main transfer room onto the import-export trolley holding a 
loaded cask or loaded MSC on a pedestal (with outer lid removed 
[if applicable] and inner lid unbolted but in place) (Room 1002). 
FHF-PR-CC9 Beyond Category 2 Same disposition as Potential Event FHF-PR-CC2. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-122 April 2005 
Table III-24. Disposition of Internal Events That Occur Inside the Fuel Handling Facility: Preparation Room (Room 1002) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1002). 
FHF-PR-CCF1 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Cask sampling and inerting system (or other pneumatic or 
pressurized system) missile due to a fractured nozzle/valve 
stem/pneumatic device (Room 1002). 
FHF-PR-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
2. Explosion hazard associated with the cask sampling and inerting 
system and the ignition of hydrogen that may have accumulated 
in the cask (Room 1002). 
FHF-PR-EI2 Beyond Category 2 Precautions taken during the cask sampling and purging process provide reasonable 
assurance that such hydrogen explosions would not occur. 
Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on the import-export 
trolley (Room 1002). 
FHF-PR-EI3 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
4. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1002). 
FHF-PR-EI4 Beyond Category 2 Same disposition as Potential Event FHF-PR-EI3. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with handling equipment or other 
preparation room equipment, including the main transfer room 
overhead crane (which can access the preparation room via an 
overhead hatch) (Room 1002). 
FHF-PR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) associated with the importexport 
trolley (Room 1002). 
FHF-PR-FT2 Beyond Category 2 Same disposition as Potential Event FHF-PR-FT1. Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) associated with the mobile 
elevated platform (Room 1002). 
FHF-PR-FT3 Beyond Category 2 Same disposition as Potential Event FHF-PR-FT1. Preventive Design- 
Procedural 
Safety 
4. Transient combustible fire in the preparation area (Room 1002). FHF-PR-FT4 Beyond Category 2 Same disposition as Potential Event FHF-PR-FT1 Preventive Design- 
Procedural 
Safety 
5. Thermal hazard (from decay heat) associated with vertical 
orientation of a loaded cask (Room 1002). 
FHF-PR-FT5 Normal Operations Same disposition as Potential Event FHF-PR-CCF1 Mitigative Procedural 
Safety 
6. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
(Room 1002). 
FHF-PR-FT6 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-123 April 2005 
Table III-24. Disposition of Internal Events That Occur Inside the Fuel Handling Facility: Preparation Room (Room 1002) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1002). 
FHF-PR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Damage or rupture of cask sampling and purging system, leading 
to a release of cask internal gases and radioactive material 
(Room 1002). 
FHF-PR-R2 Normal Operations The sampling operation is conducted so that exposure of workers to radiation is managed 
as a normal-operations dose by procedures for monitoring radiation doses and assigning 
work, which ensure that workers do not receive excessive radiation doses. Although a 
rupture leading to a radiological release would be an off-normal occurrence, any release 
and related dose would be managed as part of routine radiation protection operations. 
Mitigative Procedural 
Safety 
3. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Room 
1002). 
FHF-PR-R3 Normal Operations Any potential exposure of workers to radiation because of this event is managed as a 
normal-operations dose by procedures that ensure that workers do not receive excessive 
radiation doses. 
Mitigative Procedural 
Safety 
4. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1002). 
FHF-PR-R4 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Room 1002). FHF-PR-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a loaded cask or loaded MSC collision 
or trolley derailment followed by a load tipover or fall and a 
rearrangement of the cask internals (Room 1002). 
FHF-PR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; EI = explosion-implosion; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; HVAC = heating, ventilation, and air-conditioning; 
LWT = legal-weight truck; NA = not applicable; OWT = overweight truck; PR = preparation room; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF, the middle identifies an activity, room, or area, for example PR, and the suffix identifies the hazard category and 
event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-124 April 2005 
Table III-25. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Commercial Spent Nuclear Fuel Assembly Transfer): Main Transfer Room (Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel Transfer 
Room (Room 2001) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of the import-export trolley holding a loaded cask or 
loaded MSC on a pedestal (with inner lid in place, unbolted) 
followed by a load tipover or fall (Room 1003). 
FHF-MFTBR-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
2. Drop of a loaded cask or MSC (with inner lid in place, unbolted) 
onto the floor during the lift using the overhead bridge crane from 
the import-export trolley to the cask transfer trolley or MSC trolley, 
respectively (Room 1003). 
FHF-MFTBR-CC2A 
FHF-MFTBR-CC2B 
FHF-MFTBR-CC2C 
FHF-MFTBR-CC2D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact limiters 
and site-specific casks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. 
Preventive Design- 
Procedural 
Safety 
3. Drop of a loaded cask or MSC (with inner lid in place, unbolted) 
onto the trolley during the lift using the overhead bridge crane 
from the import-export trolley to the cask transfer trolley or MSC 
trolley, respectively (Room 1003). 
FHF-MFTBR-CC3A 
FHF-MFTBR-CC3B 
FHF-MFTBR-CC3C 
FHF-MFTBR-CC3D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MFTBR-CC2. Preventive Design- 
Procedural 
Safety 
4. Drop or collision of a loaded cask or MSC (with inner lid in place, 
unbolted) onto or against a sharp object during the lift using the 
overhead bridge crane from the import-export trolley to the cask 
transfer trolley or MSC trolley, respectively (Room 1003). 
FHF-MFTBR-CC4 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventative Design- 
Procedural 
Safety 
5. Slapdown of a loaded cask or MSC (with inner lid in place, 
unbolted) following a drop from the overhead bridge crane onto 
the edge of the pedestal, trolley, or other object during the transfer 
from the import-export trolley to the cask transfer trolley or MSC 
trolley, respectively (Room 1003). 
FHF-MFTBR-CC5A 
FHF-MFTBR-CC5B 
FHF-MFTBR-CC5C 
FHF-MFTBR-CC5D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MFTBR-CC2. Preventive Design- 
Procedural 
Safety 
6. Drop or collision of a docking ring onto or against a loaded cask or 
loaded MSC prior to entering the fuel transfer bay for unloading 
(Room 1003). 
FHF-MFTBR-CC6 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, do not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventative Procedural 
Safety 
7. Collision of a mobile elevated platform with a loaded cask or 
loaded MSC during docking ring installation activities associated 
with the cask or MSC prior to entering the fuel transfer bay for 
unloading (Room 1003). 
FHF-MFTBR-CC7 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventive Procedural 
Safety 
8. Drop or collision of a manipulator, handling equipment, or other 
miscellaneous equipment onto or against a loaded cask or loaded 
MSC prior to entering the fuel transfer bay for unloading (Room 
1003). 
FHF-MFTBR-CC8 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-CC6. Preventative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-125 April 2005 
Table III-25. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (commercial SNF Assembly Transfer): Main Transfer Room (Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel Transfer Room 
(Room 2001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
9. Derailment of the cask transfer trolley or MSC trolley holding a 
loaded cask or loaded MSC, respectively, on a pedestal (with 
inner lid in place, unbolted) followed by a load tipover or fall 
(Rooms 1003, 1004, 1005, and 1006). 
FHF-MFTBR-CC9 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-CC1. Preventive Design 
10. Collision of a trolley holding a loaded cask or loaded MSC on a 
pedestal (with outer lid removed [if applicable] and inner lid 
unbolted but in place) with the shield doors separating the main 
transfer room and the fuel transfer bay (Rooms 1003, 1004, 
1005, and 1006). 
FHF-MFTBR-CC10 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
11.Closure of the shield doors separating the main transfer room and 
the fuel transfer bay onto the trolley holding a loaded cask or 
loaded MSC on a pedestal (with outer lid removed [if applicable] 
and inner lid unbolted but in place) (Rooms 1003, 1004, 1005, and 
1006). 
FHF-MFTBR-CC11 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventive Design 
12.Drop or collision of [components associated with] a docking port 
into or against a cask or MSC (Rooms 1004, 1005, and 1006). 
FHF-MFTBR-CC12 Beyond Category 2 A design requirement ensures that a drop of or collision involving components associated 
with a docking port will not breach the lid of a cask or MSC situated at the docking port. 
Preventive Design 
13.Drop or collision of a docking port plug onto or against a cask lid 
or MSC lid (with outer lid removed [if applicable] and inner lid 
unbolted but in place) (Rooms 1004, 1005, and 1006). 
FHF-MFTBR-CC13 Beyond Category 2 Design requirements ensure that portions of a non-ITS SSC which, upon failure, could 
adversely interact with an ITS SSC and prevent its safety function from being performed 
are classified as ITS, redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC, or, for seismic interactions, designed to the same seismic DBGM as 
the ITS SSCs subjected to the potential unacceptable interaction. 
Preventive Design 
14.Drop of an inner lid onto a cask or MSC (with outer lid removed [if 
applicable]) (Rooms 1004, 1005, and 1006). 
FHF-MFTBR-CC14A 
FHF-MFTBR-CC14B 
FHF-MFTBR-CC14C 
FHF-MFTBR-CC14D 
FHF-MFTBR-CC14E 
FHF-MFTBR-CC14F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
15.Drop or collision of an SNF assembly from the spent fuel transfer 
machine back into or against a cask or MSC being unloaded 
(Room 2001). 
FHF-MFTBR-CC15A 
FHF-MFTBR-CC15B 
FHF-MFTBR-CC15C 
FHF-MFTBR-CC15D 
FHF-MFTBR-CC15E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Design and operational requirements for the spent fuel transfer machine (in 
the dry transfer areas) and fuel handling machine (in the pool) reduce the drop rate and 
collision probabilities for commercial SNF assembly transfers, including those in singleassembly 
canisters. Assemblies are assumed to breach when they are dropped or involved 
in a collision. HVAC system reliability requirements ensure availability of high-efficiency 
particulate air filtration in the primary confinement areas of the DTF and FHF during a 4-h 
mission time without credit for backup electrical power. An operational requirement 
ensures that HVAC system is working properly before normal operations begin, that the 
HVAC system is monitored for proper operation during normal operations, and that normal 
operations are suspended if the HVAC system or offsite power becomes unavailable. 
Preventive- 
Mitigative 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-126 April 2005 
Table III-25. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (commercial SNF Assembly Transfer): Main Transfer Room (Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel Transfer Room 
(Room 2001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
16.Drop or collision of an SNF assembly from the spent fuel transfer 
machine onto or against one or more SNF assembly(ies) in the 
cask or MSC being unloaded or onto one or more SNF 
assembly(ies) in the WP or MSC being loaded (Room 2001). 
FHF-MFTBR-CC16A 
FHF-MFTBR-CC16B 
FHF-MFTBR-CC16C 
FHF-MFTBR-CC16D 
FHF-MFTBR-CC16E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
17.. Impact due to horizontal movement of an SNF assembly by the 
spent fuel transfer machine before the assembly is completely 
removed from the cask or MSC (Room 2001). 
FHF-MFTBR-CC17A 
FHF-MFTBR-CC17B 
FHF-MFTBR-CC17C 
FHF-MFTBR-CC17D 
FHF-MFTBR-CC17E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
18.Drop of an SNF assembly from the spent fuel transfer machine 
onto the fuel transfer room floor (Room 2001). 
FHF-MFTBR-CC18A 
FHF-MFTBR-CC18B 
FHF-MFTBR-CC18C 
FHF-MFTBR-CC18D 
FHF-MFTBR-CC18E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
19. Collision involving an SNF assembly suspended from the spent 
fuel transfer machine with wall-mounted equipment located in the 
fuel transfer room (Room 2001). 
FHF-MFTBR-CC19A 
FHF-MFTBR-CC19B 
FHF-MFTBR-CC19C 
FHF-MFTBR-CC19D 
FHF-MFTBR-CC19E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
20.Drop or collision of an SNF assembly from the spent fuel transfer 
machine onto or against a sharp object (Room 2001). 
FHF-MFTBR-CC20A 
FHF-MFTBR-CC20B 
FHF-MFTBR-CC20C 
FHF-MFTBR-CC20D 
FHF-MFTBR-CC20E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
21.Drop or collision of an SNF assembly from the spent fuel transfer 
machine into or against an empty WP or MSC being loaded 
(Room 2001). 
FHF-MFTBR-CC21A 
FHF-MFTBR-CC21B 
FHF-MFTBR-CC21C 
FHF-MFTBR-CC21D 
FHF-MFTBR-CC21E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
22.Drop and slapdown of an SNF assembly from the spent fuel 
transfer machine (due to impact with an edge of the cask, MSC, 
WP, floor edge, WP internal baffle, etc.) during the transfer from 
the cask or MSC to a WP or MSC (Room 2001). 
FHF-MFTBR-CC22A 
FHF-MFTBR-CC22B 
FHF-MFTBR-CC22C 
FHF-MFTBR-CC22D 
FHF-MFTBR-CC22E 
No collision 
Category 1 
Category 2 
Category 1 
Category 2 
(See GET-03) Same disposition as Potential Event FHF-MFTBR-CC15. Preventive- 
Mitigative 
Design- 
Procedural 
Safety 
23.Drop or collision of handling equipment into or against an open 
MSC or an open WP filled with commercial SNF assemblies 
(Room 2001). 
FHF-MFTBR-CC23A 
FHF-MFTBR-CC23B 
No drop or collision 
Category 2 
(See GET-04) Design and operational requirements reduce the probability of dropping 
handling equipment onto or against a SNF assembly energetically enough to breach the 
assembly. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-127 April 2005 
Table III-25. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (commercial SNF Assembly Transfer): Main Transfer Room (Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel Transfer Room 
(Room 2001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
24.Drop of a WP inner lid or MSC cask inner lid (as appropriate) from 
the fuel transfer room crane onto a loaded WP or loaded MSC 
(Room 2001). 
FHF-MFTBR-CC24A 
FHF-MFTBR-CC24B 
FHF-MFTBR-CC24C 
FHF-MFTBR-CC24D 
FHF-MFTBR-CC24E 
FHF-MFTBR-CC24F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Same disposition as Potential Event FHF-MFTBR-CC14. Preventive Design- 
Procedural 
Safety 
25.Drop or collision of a transfer port seal plug from the fuel transfer 
room crane onto or against the inner lid of a loaded WP or a 
loaded MSC (Room 2001). 
FHF-MFTBR-CC25 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-CCI3. Preventive Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1003, 1004, 1005, 
1006, and 2001). 
FHF-MFTBR-CCF1 Normal Operations Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion 1. Hydrogen explosion involving batteries on a cask transfer trolley 
or an MSC trolley (Rooms 1003, 1004, 1005, and 1006). 
FHF-MFTBR-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1003). 
FHF-MFTBR-EI2 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with SNF handling equipment or other 
electrically powered handling equipment in the main transfer 
room, the fuel transfer bays, or the fuel transfer room (including 
the overhead cranes and the spent fuel transfer machine) 
(Rooms 1003, 1004, 1005, 1006, and 2001). 
FHF-MFTBR-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) associated with an importexport 
trolley, a cask transfer trolley or an MSC trolley holding a 
filled or partially filled cask or MSC, respectively, with or without 
inner lid in place (but not sealed). (Rooms 1003, 1004, 1005, and 
1006). 
FHF-MFTBR-FT2 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-FT1. Preventive Design- 
Procedural 
Safety 
3. Electrical fire associated with a WP trolley holding a partially filled 
or filled WP, with or without inner lid in place (but not sealed). 
(Rooms 1003, 1004, and 1006). 
FHF-MFTBR-FT3 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-FT1. Preventive Design- 
Procedural 
Safety 
4. Fire/explosion (battery/electrical fire) associated with the mobile 
elevated platform (Room 1003). 
FHF-MFTBR-FT4 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-FT1. Preventive Design- 
Procedural 
Safety 
5. HEPA filter fire due to excessive radioactive decay within the filter 
bed (Room 1007) 
FHF-MFTBR-FT5 Beyond Category 2 Operation requirements ensure that the operating surface temperatures of high-efficiency 
particulate air (HEPA) filters is maintained such that they can not catch on fire under 
normal operation or in the event of a shutdown of the HVAC system. 
Preventive Procedural 
Safety 
6. Intact or non-intact SNF overheating due to a loss of cooling 
resulting in excessive temperature and possible zircaloy cladding 
(or other cladding) unzipping or cladding failure due to excessive 
hoop stresses (Rooms 1003, 1004, 1005, 1006, and 2001). 
FHF-MFTBR-FT6 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-128 April 2005 
Table III-25. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (commercial SNF Assembly Transfer): Main Transfer Room (Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel Transfer Room 
(Room 2001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
7. Thermal hazard (from decay heat) associated with a vertical 
orientation of a loaded cask (sealed/inerted or unsealed/noninerted) 
or loaded, unsealed/non-inerted WP (Rooms 1003, 1004, 
1005, 1006, and 2001). 
FHF-MFTBR-FT7 Normal Operations Same disposition as Potential Event FHF-MFTBR-CCF1. Mitigative Procedural 
Safety 
8. Transient combustible fire in the main transfer room, the fuel 
transfer bays, or the fuel transfer room (Rooms 1003, 1004, 1005, 
1006, and 2001). 
FHF-MFTBR-FT8 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1003, 1004, 1005, 1006, and 2001). 
FHF-MFTBR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Docking ring failure leads to a radiological release (Room 2001). FHF-MFTBR-R2 NA (no significant 
exposure) 
Same disposition as Potential Event FHF-MFTBR-R5. Mitigative Procedural 
Safety 
3. Radiological release due to installation of incorrect docking ring 
(Room 2001). 
FHF-MFTBR-R3 NA (no significant 
exposure) 
Same disposition as Potential Event FHF-MFTBR-R5. Mitigative Procedural 
Safety 
4. Thermal expansion of gases or other loss of confinement in an 
unsealed cask or MSC, leading to radiological release (Rooms 
1003, 1004, 1005, 1006, and 2001). 
FHF-MFTBR-R4 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Design- 
Procedural 
Safety 
5. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1003, 1004, 1005, 1006, and 2001). 
FHF-MFTBR-R5 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
6. Inadvertent opening of a fuel transfer bay door, leading to a 
worker exposure (Rooms 1003, 1004, and 1005). 
FHF-MFTBR-R6 Beyond Category 2 Design requirements and operating procedures ensure that event sequences initiated by 
actions that accidentally expose workers to radiation are not Category 1. 
Preventive Design- 
Procedural 
Safety 
7. Radiation-induced damage to a facility SSC (Rooms 1003, 1004, 
1005, 1006, and 2001) 
FHF-MFTBR-R7 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a drop or slapdown of a loaded, 
unsealed cask or MSC from the main transfer room overhead 
crane and a rearrangement of the container internals (Room 
1003). 
FHF-MFTBR-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with an import-export trolley, a cask transfer 
trolley, or an MSC trolley holding a loaded, unsealed cask or MSC 
(as applicable) derailment followed by a load tipover or fall and a 
rearrangement of the container internals (Rooms 1003, 1004, 
1005, and 1006). 
FHF-MFTBR-F2 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-F1. Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-129 April 2005 
Table III-25. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (commercial SNF Assembly Transfer): Main Transfer Room (Room 1003), Fuel Transfer Bay (Rooms 1004, 1005 and 1006), Fuel Transfer Room 
(Room 2001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine into a cask, MSC, or WP and a 
rearrangement of the cask, MSC, or WP internals (Room 2001). 
FHF-MFTBR-F3 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-F1. Additionally, a design requirement 
ensures that waste packages are designed to preclude criticality with credit for moderator 
control and without credit for burnup. Demonstration of compliance must account for the 
bowing of fuel rods or other rearrangement of fissile material that may occur due to a drop 
or other handling incident. Design and operational requirements ensure that moderator 
control is in effect. 
Preventive Design- 
Procedural 
Safety 
4. Criticality associated with a drop of an SNF assembly from the 
spent fuel transfer machine and a rearrangement of the fuel rods 
that comprise the assembly due to impact (Room 2001). 
FHF-MFTBR-F4 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-F3. Preventive Design- 
Procedural 
Safety 
5. Criticality associated with the drop of heavy equipment onto a 
loaded, open cask, MSC, or WP and a rearrangement of the 
container internals (Room 2001). 
FHF-MFTBR-F5 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-F3. Preventive Design- 
Procedural 
Safety 
6. Criticality associated with a misload of a WP or an MSC (Room 
2001). 
FHF-MFTBR-F6 Beyond Category 2 Same disposition as Potential Event FHF-MFTBR-F3. Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; DTF = dry transfer facility (DTF 1 and DTF 2); EI = explosion-implosion; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; MFTBR 
= main fuel transfer bay room; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF. If localized, the middle identifies an activity, room, or area, for example MFTBR, and the suffix identifies the 
hazard category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, 
for example A. 
Additional room(s) with potential events in this table: Room 1007  Remote HEPA filter room 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-130 April 2005 
Table III-26. Disposition Internal Events That Occur Inside the Fuel Handling Facility (Canister Transfer): Main Transfer Room (Room 1003) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Drop of a loaded cask (with inner lid in place, unbolted) from the 
main transfer room overhead crane onto the floor during the 
transfer from a pedestal on the import-export trolley to the cask 
transfer station (Room 1003). 
FHF-MTR-CC1A 
FHF-MTR-CC1B 
FHF-MTR-CC1C 
FHF-MTR-CC1D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact limiters 
and site-specific casks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. 
Preventive Design- 
Procedural 
Safety 
2. Drop or collision of a loaded cask (with inner lid in place, unbolted) 
from the main transfer room overhead crane onto or against a 
sharp object during the transfer from a pedestal on the importexport 
trolley to the cask transfer station (Room 1003). 
FHF-MTR-CC2 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventative Design- 
Procedural 
Safety 
3. Drop or collision of a loaded cask (with inner lid in place, unbolted) 
from the main transfer room overhead crane into or against the 
canister transfer station (Room 1003). 
FHF-MTR-CC3A 
FHF-MTR-CC3B 
FHF-MTR-CC3C 
FHF-MTR-CC3D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTR-CC1. For collisions, a 
design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
4. Slapdown of a loaded cask (with inner lid in place, unbolted) in the 
main transfer room due to a cask corner drop from the main 
transfer room overhead crane onto the edge of the pedestal or 
import-export trolley (Room 1003). 
FHF-MTR-CC4A 
FHF-MTR-CC4B 
FHF-MTR-CC4C 
FHF-MTR-CC4D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTR-CC1. Preventive Design- 
Procedural 
Safety 
5. Drop or collision of a loaded cask (with inner lid in place, unbolted) 
from the main transfer room overhead crane into or against the 
canister transfer station (Room 1003). 
FHF-MTR-CC5A 
FHF-MTR-CC5B 
FHF-MTR-CC5C 
FHF-MTR-CC5D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTR-CC1. For collisions, a design 
requirement limits speed for crane transfers such that a collision at the maximum speed 
could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval canister, 
or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
6. Slapdown of a loaded cask (with inner lid in place, unbolted) onto 
the floor, cask slapdown into the canister transfer station, or cask 
slapdown into a wall; all due to off-center cask lowering into the 
canister transfer station (Room 1003). 
FHF-MTR-CC6A 
FHF-MTR-CC6B 
FHF-MTR-CC6C 
FHF-MTR-CC6D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTR-CC1. Preventive Design- 
Procedural 
Safety 
7. Drop or collision of a manipulator, handling equipment, or other 
miscellaneous equipment onto or against a loaded cask (with 
inner lid in place, unbolted) prior to entering the canister transfer 
station for unloading (Room 1003). 
FHF-MTR-CC7 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, can not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-131 April 2005 
Table III-26. Disposition Internal Events That Occur Inside the Fuel Handling Facility (Canister Transfer): Main Transfer Room (Room 1003) (Continued) 
Disposition of a Potential Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Drop of a cask inner lid, as appropriate, from the main transfer 
room overhead crane into a loaded cask to be unloaded 
(Room 1003). 
FHF-MTR-CC8A 
FHF-MTR-CC8B 
FHF-MTR-CC8C 
FHF-MTR-CC8D 
FHF-MTR-CC8E 
FHF-MTR-CC8F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
9. Drop or collision of handling equipment into or against an open 
cask loaded with a DPC, a DOE HLW canister, a naval SNF 
canister, or a [standardized] DOE SNF canister (Room 1003). 
FHF-MTR-CC9A 
FHF-MTR-CC9B 
FHF-MTR-CC9C 
FHF-MTR-CC9D 
FHF-MTR-CC9E 
FHF-MTR-CC9F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) In this potential event, a drop has to occur to cause a collision because the 
equipment would be suspended above the canister. Design and operational requirements 
reduce the drop probability. An operational requirement ensures the establishment of a 
maximum lift height limit for handling equipment suspended above DOE SNF canisters. A 
design requirement ensures that the handling equipment is not capable of causing an event 
sequence due to a breach of a DOE SNF canister if dropped from within the lift-height limit. 
Design and operational requirements limit the probability of exceeding the lift height. 
Preventive Design- 
Procedural 
Safety 
10.Drop or collision of a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a naval SNF canister from the main transfer 
room overhead crane back into or against the cask being 
unloaded (Room 1003). 
FHF-MTR-CC10A 
FHF-MTR-CC10B 
FHF-MTR-CC10C 
FHF-MTR-CC10D 
FHF-MTR-CC10E 
FHF-MTR-CC10F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Design and operational requirements reduce the drop probability. A design 
requirement limits lift heights for DOE SNF canisters, DOE HLW canister, naval canisters, 
and DOE SNF multicanister overpacks. Design and operational requirements limit the 
probability of exceeding the lift height. Design requirements ensure that standardized DOE 
SNF canisters, would withstand without breach a drop of another standardized DOE SNF 
canister and that MCOs would withstand without breach a drop of another MCO dropped 
from within its lift-height limits. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. A design requirement ensures that a DOE SNF canister in a cask, WP, staging 
rack, or staging pit would withstand without breach the drop of a DOE HLW canister on top 
of the DOE SNF canister from within their lift height limits. Neither naval canisters nor 
MCOs are staged in staging racks. For collisions, a design requirement limits speed for 
crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
11.Impact due to horizontal movement of a naval SNF canister, a 
DPC, a DOE HLW canister, or a [standardized] DOE SNF canister 
with the main transfer room overhead crane before the canister is 
completely removed from the cask (Room 1003). 
FHF-MTR-CC11 Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force to 
breach a transportation cask, MSC, waste package, or canister as the result of attempts to 
overcome mechanical constraints. 
Preventive Design 
12. Drop and slapdown of a naval SNF canister, a DOE HLW canister 
or a [standardized] DOE SNF canister from the main transfer 
room overhead crane into the side of the canister transfer station 
(due to impact with an edge of the cask, MSC, WP, floor edge, 
WP or MSC internal baffle, etc.) during the transfer from the cask 
to a WP or MSC (as appropriate) (Room 1003). 
FHF-MTR-CC12A 
FHF-MTR-CC12B 
FHF-MTR-CC12C 
FHF-MTR-CC12D 
FHF-MTR-CC12E 
FHF-MTR-CC12F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event FHF-MTR-CC10. Preventive Design- 
Procedural 
Safety 
13.Drop and slapdown of a DPC from the main transfer room 
overhead crane into the side of the canister transfer station (due 
to impact with an edge of the cask, MSC, floor edge, MSC internal 
baffle, etc.) during the transfer from the cask to an MSC (Room 
1003). 
FHF-MTR-CC13A 
FHF-MTR-CC13B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Design and operational requirements reduce the 
drop probability. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-132 April 2005 
Table III-26. Disposition Internal Events That Occur Inside the Fuel Handling Facility (Canister Transfer): Main Transfer Room (Room 1003) (Continued) 
Disposition of a Potential Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
14.Drop or collision of a dual-purpose canister, a DOE HLW canister, 
a [standardized] DOE SNF canister, or a naval SNF canister from 
the main transfer room overhead crane onto or against a sharp 
object or edge in the canister transfer station (Room 1003). 
FHF-MTR-CC14 Beyond Category 2 Same disposition as Potential Event FHF-MTR-CC2. Preventive Design- 
Procedural 
Safety 
15.Drop of a DPC, a DOE HLW canister, a [standardized] DOE SNF 
canister, or a naval SNF canister from the main transfer room 
overhead crane onto the canister transfer station floor (Room 
1003). 
FHF-MTR-CC15A 
FHF-MTR-CC15B 
FHF-MTR-CC15C 
FHF-MTR-CC15D 
FHF-MTR-CC15E 
FHF-MTR-CC15F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event FHF-MTR-CC10. Preventive Design- 
Procedural 
Safety 
16.Drop or collision of a DOE HLW canister, a [standardized] DOE 
SNF canister, or a naval SNF canister from the main transfer 
room crane into or against an empty WP or empty MSC (Room 
1003). 
FHF-MTR-CC16A 
FHF-MTR-CC16B 
FHF-MTR-CC16C 
FHF-MTR-CC16D 
FHF-MTR-CC16E 
FHF-MTR-CC16F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05) Same disposition as Potential Event FHF-MTR-CC10. Preventive Design- 
Procedural 
Safety 
17.Drop or collision of a naval SNF canister from the main transfer 
room crane into or against an empty WP (Room 1003). 
FHF-MTR-CC17A 
FHF-MTR-CC17B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event FHF-MTRCC13. 
For collisions, a design requirement limits speed for crane transfers such that a 
collision at the maximum speed could not breach an MSC, transportation cask, transfer 
cask, DPC, DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
18.Drop or collision of a DPC from the main transfer room crane into 
or against an empty MSC (Room 1003). 
FHF-MTR-CC18A 
FHF-MTR-CC18B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event FHF-MTRCC17. 
Preventive Design- 
Procedural 
Safety 
19.Collision involving a DPC, a DOE HLW canister, a [standardized] 
DOE SNF canister, or a naval SNF canister and the canister 
transfer station (Room 1003). 
FHF-MTR-CC19 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
20.Drop or collision of a DOE HLW canister from the main transfer 
room overhead crane onto or against another DOE HLW canister 
or a [standardized] DOE SNF canister in a WP or in an MSC 
(Room 1003). 
FHF-MTR-CC20A 
FHF-MTR-CC20B 
No drop 
Category 2 
(See GET-05 Sequences A and B only) Same disposition as Potential Event FHF-MTRCC17. 
Preventive Design- 
Procedural 
Safety 
21.Drop or collision of a [standardized] DOE SNF canister from the 
main transfer room overhead crane onto or against a DOE HLW 
canister in a WP or in an MSC (Room 1003). 
FHF-MTR-CC21C 
FHF-MTR-CC21D 
FHF-MTR-CC21E 
FHF-MTR-CC21F 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-05 Sequences C to F only) Same disposition as Potential Event FHF-MTRCC10. 
Preventive Design- 
Procedural 
Safety 
22.Drop or collision of handling equipment into or against an open 
WP or MSC loaded with a DPC, DOE HLW canisters, and/or 
[standardized] DOE SNF canisters, and/or a naval SNF canister, 
as appropriate (Room 1003). 
FHF-MTR-CC22A 
FHF-MTR-CC22B 
FHF-MTR-CC22C 
FHF-MTR-CC22D 
FHF-MTR-CC22E 
FHF-MTR-CC22F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-06) Same disposition as Potential Event FHF-MTR-CC9. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-133 April 2005 
Table III-26. Disposition Internal Events That Occur Inside the Fuel Handling Facility (Canister Transfer): Main Transfer Room (Room 1003) (Continued) 
Disposition of a Potential Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
23.Drop of a WP inner lid or MSC cask inner lid, as appropriate, from 
the main transfer room overhead crane onto a filled (loaded) WP 
or loaded MSC (Room 1003). 
FHF-MTR-CC23A 
FHF-MTR-CC23B 
FHF-MTR-CC23C 
FHF-MTR-CC23D 
FHF-MTR-CC23E 
FHF-MTR-CC23F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Same disposition as Potential Event FHF-MTR-CC8. Preventive Design- 
Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Room 1003). 
FHF-MTRCCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is inside sealed canisters, therefore this event does not occur unless an event 
sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible 
outcome of any event that exposes SNF to air. Consequence analyses account for the 
possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Hydrogen explosion involving batteries on the import-export trolley 
(Room 1003). 
FHF-MTREI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1003). 
FHF-MTREI2 Beyond Category 2 Same disposition as Potential Event FHF-MTR-EI1. Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with SNF and HLW handling equipment 
in the main transfer room (including the overhead crane, 
manipulators, the movable platform/sleeve assembly, etc.) 
(Room 1003). 
FHF-MTRFT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) associated with the importexport 
trolley (Room 1003). 
FHF-MTRFT2 Beyond Category 2 Same disposition as Potential Event FHF-MTR-FT1. Preventive Design- 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) associated with the mobile 
elevated platform (Room 1003). 
FHF-MTRFT3 Beyond Category 2 Same disposition as Potential Event FHF-MTR-FT1. Preventive Design- 
Procedural 
Safety 
4. Thermal hazard (from decay heat) associated with vertical 
orientation of a loaded cask (with inner lid in place, unbolted) 
(Room 1003). 
FHF-MTR-FT4 NAAccounted for in 
consequence 
analyses, if applicable 
Same disposition as Potential Event FHF-MTR-CCF1. NA NA 
5. Overheating of a loaded cask, WP, or MSC due to a loss of 
cooling resulting in excessive temperature and possible damage 
to canister contents (Room 1003). 
FHF-MTRFT5 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
6. Transient combustible fire in the main transfer room (Room 1003). FHF-MTR-FT6 Beyond Category 2 Same disposition as Potential Event FHF-MTR-FT2. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Room 1003). 
FHF-MTRR1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-134 April 2005 
Table III-26. Disposition Internal Events That Occur Inside the Fuel Handling Facility (Canister Transfer): Main Transfer Room (Room 1003) (Continued) 
Disposition of a Potential Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Room 1003). 
FHF-MTR-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Thermal expansion of gases or other loss of confinement in an 
unsealed cask, leading to radiological release (Room 1003). 
FHF-MTR-R3 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
4. Inadvertent opening of the main transfer room shield door, leading 
to a worker exposure (Room 1003). 
FHF-MTR-R4 Beyond Category 2 Design requirements and operating procedures ensure that event sequences initiated by 
actions that accidentally expose workers to radiation are not Category 1. 
Preventive Design- 
Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Room 1003). FHF-MTR-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a drop or slapdown of a loaded cask or 
MSC from the main transfer room overhead crane and a 
rearrangement of the cask or MSC internals (Room 1003). 
FHF-MTRF1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a drop or slapdown of a DPC, a 
[standardized] DOE SNF canister, a naval SNF canister, or a DOE 
HLW canister and a rearrangement of canister internals 
(Room 1003). 
FHF-MTRF2 Beyond Category 2 Same disposition as Potential Event FHF-MTR-F1. Additionally, a design requirement 
ensures that dropping a DOE SNF canister within its design basis does not lead to a 
criticality. Demonstration of compliance for the staging rack must account for the most 
reactive configuration of DOE SNF canisters with credit for moderator control. Design and 
operational requirements ensure that moderator control is in effect. There is no potential for 
criticality of DOE HLW canisters. Criticality of a naval canister following a drop, or other 
impact event, has been evaluated to be Beyond Category 2 based upon probabilities of 
independent events required for criticality. 
Preventive Design- 
Procedural 
Safety 
3 Criticality associated with the drop of heavy equipment onto a 
loaded, open cask, MSC, or WP and a rearrangement of the 
container internals (Room 1003). 
FHF-MTR-F3 Beyond Category 2 Same disposition as Potential Event FHF-MTR-F1. Additionally, an unsealed waste 
package remains subcritical with credit for moderator control and without credit for burnup. 
Design and operational requirements ensure that moderator control is in effect. A design 
requirement ensures that sealed waste packages are designed such that drops, collisions, 
and other handling impacts within their design bases, allowing for rearrangement of the 
waste package internals and without credit for burnup, cannot lead to a nuclear criticality. 
Preventive Design- 
Procedural 
Safety 
4. Criticality associated with a misload of a WP or an MSC (Room 
1003). 
FHF-MTR-F4 Beyond Category 2 Same disposition as Potential Event FHF-MTR-F3. Preventive Design- 
Procedural 
Safety 
NOTES: BWR = boiling water reactor; CC = collision-crushing; CCF = chemical-contamination flooding; DBGM = design basis ground motion; DOE = U.S. Department of Energy; EI = explosion-implosion; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = 
generalized event tree; HLW = high-level radioactive waste; MTR = main transfer room; NA = not applicable; PWR = pressurized water reactor; R = radiation; SNF = spent nuclear fuel. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF, the middle identifies an activity, room, or area, for example MTR, and the suffix identifies the hazard category 
and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for example A. 
Additional room(s) with potential events in this table: Room 1007  Remote HEPA filter room 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-135 April 2005 
Table III-27. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Closure): Main Transfer Room (Room 1003), Waste Package Positioning Cell (Room 1013), Waste Package Closure Cell (Room 2006) 
Event Sequence 
Designator Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the trolley holding the loaded, unsealed WP, 
and the shield doors between the main transfer room and the WP 
positioning cell (Rooms 1003 and 1013). 
FHF-MTRWPCC-CC1 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design 
2. Shield doors between the main transfer room and the WP 
positioning cell close on the trolley holding the loaded, unsealed 
WP (Rooms 1003 and 1013). 
FHF-MTRWPCC-CC2 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventative Design 
3. Derailment of a trolley holding a loaded, unsealed WP followed by 
a load tipover or fall (Rooms 1003 and 1013). 
FHF-MTRWPCC-CC3 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventative Design 
4. Drop or collision of equipment from the main transfer room 
overhead crane, including a docking ring, lifting equipment, or a 
lifting fixture, onto or against a loaded, unsealed WP or WP inner 
lid (Room 1003). 
FHF-MTRWPCC-CC4 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventative Procedural 
Safety 
5. Drop or collision of an unsealed, loaded WP from the main transfer 
room overhead crane back into or against the canister transfer 
station (Room 1003). 
FHF-MTRWPCC-CC5A 
FHF-MTRWPCC-CC5B 
FHF-MTRWPCC-CC5C 
FHF-MTRWPCC-CC5D 
FHF-MTRWPCC-CC5E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Design and operational requirements reduce the drop probability. Design 
and operational requirements specify lift-height limits for unsealed waste packages 
whenever waste packages are transferred. If the limit can not be met, impact absorbers 
are provided. Design and operational requirements limit the probability of exceeding the 
lift-height limit. Canister design requirements and the reliability of fabrication processes 
limit the probability that a DOE SNF canister or DOE multicanister overpack is defective. 
For collisions, a design requirement limits speed for crane transfers such that a collision at 
the maximum speed could not breach an MSC, transportation cask, transfer cask, DPC, 
DOE or naval canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
6. Drop of an unsealed, loaded WP from the main transfer room 
overhead crane onto the main transfer room floor during the lift 
and transfer to the WP positioning cell pedestal and trolley (Room 
1003). 
FHF-MTRWPCC-CC6A 
FHF-MTRWPCC-CC6B 
FHF-MTRWPCC-CC6C 
FHF-MTRWPCC-CC6D 
FHF-MTRWPCC-CC6E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event FHF-MTRWPCC-CC5. Preventive Design- 
Procedural 
Safety 
7. Drop of an unsealed, loaded WP from the main transfer room 
overhead crane onto the pedestal on the WP positioning cell trolley 
during the lift and transfer to the WP positioning cell pedestal and 
trolley (Room 1003). 
FHF-MTRWPCC-CC7A 
FHF-MTRWPCC-CC7B 
FHF-MTRWPCC-CC7C 
FHF-MTRWPCC-CC7D 
FHF-MTRWPCC-CC7E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event FHF-MTRWPCC-CC5. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-136 April 2005 
Table III-27. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Closure): Main Transfer Room (Room 1003), Waste Package Positioning Cell (Room 1013), Waste Package Closure Cell (Room 
2006) (Continued) 
Event Sequence 
Designator Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Drop or collision of an unsealed, loaded WP from the main transfer 
room overhead crane onto or against a sharp object during the lift 
and transfer to the WP positioning cell pedestal and trolley (Room 
1003). 
FHF-MTRWPCC-CC8 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventive Design- 
Procedural 
Safety 
9. Slapdown of a loaded, unsealed WP onto the floor, into a wall, or 
into nearby equipment following a drop from the main transfer 
room overhead crane onto the edge of the trolley, pedestal, or 
other equipment during the lift and transfer to the WP positioning 
cell pedestal and trolley (Room 1003). 
FHF-MTRWPCC-CC9A 
FHF-MTRWPCC-CC9B 
FHF-MTRWPCC-CC9C 
FHF-MTRWPCC-CC9D 
FHF-MTRWPCC-CC9E 
No drop 
Category 2 
No waste form breach 
Beyond Category 2 
Beyond Category 2 
(See GET-07) Same disposition as Potential Event FHF-MTRWPCC-CC5. Preventive Design- 
Procedural 
Safety 
10. Lid drop onto a WP from the lid placement fixture equipment 
during the welding process (Room 1013). 
FHF-MTRWPCC-CC10A 
FHF-MTRWPCC-CC10B 
FHF-MTRWPCC-CC10C 
FHF-MTRWPCC-CC10D 
FHF-MTRWPCC-CC10E 
FHF-MTRWPCC-CC10F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, 
transfer cask, site-specific cask, or waste package to ensure that a lid drop onto a DOE 
canister within that breaches the canister is a beyond Category 2 event sequence. Design 
and operational requirements limit the probability of exceeding the lift height. Canister 
design requirements and the reliability of fabrication processes limit the probability that a 
DOE SNF canister or DOE multicanister overpack is defective. 
Preventive Design- 
Procedural 
Safety 
11. Equipment drop onto a WP during the welding process (Room 
1013). 
FHF-MTRWPCC-CC11 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-CC4. Preventative Procedural 
Safety 
12. Drop or collision of equipment from the main transfer room 
overhead crane onto or against a loaded, sealed WP positioned 
on a pedestal on a trolley (Room 1003). 
FHF-MTRWPCC-CC12 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-CC4. Preventative Procedural 
Safety 
13. Collision involving a trolley holding the loaded, sealed WP and the 
shield doors between the WP positioning cell and the main 
transfer room (Rooms 1003 and 1013). 
FHF-MTRWPCC-CC13 Beyond Category 2 (See GET-22) Same disposition as Potential Event FHF-MTRWPCC-CC1. Preventative Design 
14. Shield doors between the WP positioning cell and the main 
transfer room close on the trolley holding the loaded, sealed WP 
(Rooms 1003 and 1013). 
FHF-MTRWPCC-CC14 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-CC2. Preventative Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1003, 1013, and 2006). 
FHF-MTRWPCC-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAOxidation of the fuel matrix is a possible outcome of any event that exposes SNF to 
air. Consequence analyses account for the possibility of oxidation, as applicable. 
Oxidation of failed commercial SNF is expected as a part of normal operations whenever 
commercial SNF is exposed to air. Any resulting potential exposure of workers to radiation 
is managed as a normal-operations dose by procedures that ensure that workers do not 
receive excessive radiation doses. 
NA 
Mitigative 
NA 
Procedural 
Safety 
Explosion-Implosion 1. Explosion hazard associated with the WP purging and inerting 
system and the ignition of hydrogen that may have accumulated in 
the WP (Room 1013). 
FHF-MTRWPCC-EI1 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-137 April 2005 
Table III-27. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Closure): Main Transfer Room (Room 1003), Waste Package Positioning Cell (Room 1013), Waste Package Closure Cell (Room 
2006) (Continued) 
Event Sequence 
Designator Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. WP inerting system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Room 1013). 
FHF-MTRWPCC-EI2 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on the WP closure transfer 
trolley. (Rooms 1003 and 1013). 
FHF-MTRWPCC-EI3 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with handling equipment or other 
electrically powered equipment in the WP closure cell and the WP 
positioning cell, including the overhead cranes and welding 
subsystem in the WP closure cell (Rooms 1003, 1013, and 2006). 
FHF-MTRWPCC-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire hazard associated with the WP transfer trolley 
holding a loaded, unsealed WP or a WP closure transfer trolley 
holding a loaded, unsealed or sealed WP (Rooms 1003 and 1013). 
FHF-MTRWPCC-FT2 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-FT1. Preventive Design- 
Procedural 
Safety 
3. Intact or non-intact SNF overheating or damage to canister 
contents due to a loss of cooling resulting in excessive 
temperature and possible zircaloy cladding (or other cladding) 
unzipping or cladding failure due to excessive hoop stresses 
(Rooms 1003, 1013, and 2006). 
FHF-MTRWPCC-FT3 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
4. Canister/fuel damage by burn-through during welding process/heat 
damage (Room 1013). 
FHF-MTRWPCC-FT4 NA Burn-through of the inner lid is not possible with the gas tungsten arc welding process used 
for the closure welds. 
NA NA 
5. Thermal hazard/canister contents overheating/SNF assemblies 
overheating in a WP during the welding process resulting in 
excessive cladding temperature and possible zircaloy cladding (or 
other cladding) unzipping (Room 1013). 
FHF-MTRWPCC-FT5 NA Overheating of the waste package contents due to welding is not possible using the gas 
tungsten arc welding process which used for the closure welds. 
NA NA 
6. Transient combustible fire in the WP closure cell and the WP 
positioning cell (Room 1013). 
FHF-MTRWPCC-FT6 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1003, 1013, and 2006). 
FHF-MTRWPCC-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Glovebox leak leads to a radiological release (Room 2008). FHF-MTRWPCC-R2 Normal Operations Potential exposure of workers to radiation from a glovebox leak is managed as a normaloperations 
dose by routine procedures that ensure that workers do not receive excessive 
radiation doses. 
Mitigative Procedural 
Safety 
3. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1003, 1013, and 2006). 
FHF-MTRWPCC-R3 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-138 April 2005 
Table III-27. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Closure): Main Transfer Room (Room 1003), Waste Package Positioning Cell (Room 1013), Waste Package Closure Cell (Room 
2006) (Continued) 
Event Sequence 
Designator Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
4. Inadvertent opening of a transfer bay shield door or the WP 
positioning cell shield door, leading to a worker exposure 
(Rooms 1003 and 1013). 
FHF-MTRWPCC-R4 Beyond Category 2 Design requirements and operating procedures ensure that event sequences initiated by 
actions that accidentally expose workers to radiation are not Category 1. 
Preventive Design- 
Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1003, 1013, 
and 2006). 
FHF-MTRWPCC-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley holding a sealed or unsealed 
WP derailment followed by a load tipover or fall and rearrangement 
of the container internals (Rooms 1003 and 1013). 
FHF-MTRWPCC-F1 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-CC3. Preventive Design 
2. Criticality associated with a drop or slapdown of a loaded, 
unsealed WP from the main transfer room overhead crane and a 
rearrangement of the container internals (Room 1003). 
FHF-MTRWPCC-F2 Beyond Category 2 A design requirement ensures that an unsealed WP that is dropped onto an essentially 
unyielding surface from within its lift-height limits would not spill its contents. A design 
requirement ensures that waste packages are designed to preclude criticality with credit for 
moderator control and without credit for burnup. Demonstration of compliance must 
account for the bowing of fuel rods or other rearrangement of fissile material that may occur 
due to a drop or other handling incident. Design and operational requirements ensure that 
moderator control is in effect. 
Preventive Design- 
Procedural 
Safety 
3. Criticality associated with the drop of heavy equipment onto a 
loaded, unsealed WP and a rearrangement of the container 
internals (Rooms 1003 and 1013). 
FHF-MTRWPCC-F3 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPCC-F2. Preventive Design- 
Procedural 
Safety 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; CHF = Canister Handling Facility; DTF = dry transfer facility (DTF 1 and DTF 2); DOE = U.S. Department of Energy; EI = explosion-implosion; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = 
generalized event tree; HLW = high-level radioactive waste; MTRWPCC = main transfer room waste package closure cell; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF, the middle identifies an activity, room, or area, for example MTRWPCC, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-139 April 2005 
Table III-28. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Loadout): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a trolley holding a loaded, sealed WP followed by a 
load tipover or fall (Room 1003). 
FHF-MTRWPLO-CC1 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventative Design 
2. Drop of a loaded, sealed WP from a main transfer room overhead 
crane onto the floor during transfer from the trolley to the survey 
area or from the survey area to the tilting machine (Room 1003). 
FHF-MTRWPLO-CC2A 
FHF-MTRWPLO-CC2B 
FHF-MTRWPLO-CC2C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Design and operational requirements reduce the drop probability. 
Design and operational requirements limit the lift height of waste packages in horizontal 
and vertical orientations. Design requirements ensure that waste packages withstand 
without breaching drops and tipovers within their lift height limits. Design and operational 
requirements limit the probability of exceeding the lift height. 
Preventive Design- 
Procedural 
Safety 
3. Drop or collision of a loaded, sealed WP from a main transfer 
room overhead crane onto or against a sharp object (including the 
tilting machine) during transfer from the trolley to the survey area 
or from the survey area to the tilting machine (Room 1003). 
FHF-MTRWPLO-CC3 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventative Design- 
Procedural 
Safety 
4. Slapdown of a loaded, sealed WP from a main transfer room 
overhead crane to the cell floor during transfer from the trolley to 
the survey area due to drop from the overhead crane onto the 
edge of the pedestal on the trolley, the edge of the trolley, or 
another object on the floor (Room 1003). 
FHF-MTRWPLO-CC4 No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event FHF-MTRWPLO-CC2. Preventive Design- 
Procedural 
Safety 
5. Slapdown (either forward into the WP turntable or backward onto 
the floor) of a loaded, sealed waste package in the tilting machine 
from a main transfer room overhead crane during the lowering of 
the WP to the horizontal position on the pallet previously placed 
on the WP turntable (Room 1003). 
FHF-MTRWPLO-CC5 No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event FHF-MTRWPLO-CC2. Additionally, a 
design requirement prevents backward slapdowns associated with the tilting machine for 
waste packages. 
Preventive Design- 
Procedural 
Safety 
6. Collision of the tilting machine against a loaded, sealed WP on a 
pallet on the WP turntable (Room 1003). 
FHF-MTRWPLO-CC6 Beyond Category 2 Design and operational requirements ensure that an impact or collision between the 
trunnion collar removal machine, WP turntable, or WP tilting machine and a WP will not 
breach the WP or cause it to fall off the emplacement pallet. 
Preventative Design- 
Procedural 
Safety 
7. Drop or collision of a lifting collar from a main transfer room 
overhead crane onto or against a loaded, sealed waste package 
after removal of the collar from the WP collar removal machine 
(Room 1003). 
FHF-MTRWPLO-CC7 Beyond Category 2 Operational requirements establish lift-height limits for handling equipment and other 
equipment associated with the WP, including lifting collars (or trunnion collars), yokes, 
docking rings, and WP-closure equipment. The lift-height limits ensure that the handling 
equipment can not breach a sealed WP if dropped onto or collided into the WP from within 
the lift-height limit. Furthermore, the lift-height limits ensure that a drop of equipment from 
within the lift-height limit can not initiate an event sequence if the WP inner lid is in place, 
but unsealed. An operational requirement ensures that the inner lid, once set in place, is 
not removed from the WP except in a remediation situation. 
Preventative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-140 April 2005 
Table III-28. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Loadout): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Collision or impact of the lifting collar removal machine and a 
loaded, sealed WP placed on a pallet positioned on the WP 
turntable (Room 1003). 
FHF-MTRWPLO-CC8 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC6. Preventive Design- 
Procedural 
Safety 
9. Drop of a loaded, sealed WP and pallet from a main transfer room 
overhead crane onto the floor during transfer of the WP and pallet 
from the WP turntable to the WP transporter bedplate 
(Room 1003). 
FHF-MTRWPLO-CC9A 
FHF-MTRWPLO-CC9B 
FHF-MTRWPLO-CC9C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event FHF-MTRWPLO-CC2. Preventive Design- 
Procedural 
Safety 
10.Drop of a loaded, sealed WP and pallet from a main transfer room 
overhead crane onto the WP transporter bedplate during transfer 
of the WP and pallet from the WP turntable to the WP transporter 
bedplate (Room 1003). 
FHF-MTRWPLO-CC10A 
FHF-MTRWPLO-CC10B 
FHF-MTRWPLO-CC10C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event FHF-MTRWPLO-CC2. Preventive Design- 
Procedural 
Safety 
11.Drop or collision of a loaded, sealed WP on a pallet from a main 
transfer room overhead crane onto or against a sharp object 
during transfer of the WP and pallet from the WP turntable to the 
WP transporter bedplate (Room 1003). 
FHF-MTRWPLO-CC11A 
FHF-MTRWPLO-CC11B 
FHF-MTRWPLO-CC11C 
No drop 
No breach 
Beyond Category 2 
(See GET-08) Same disposition as Potential Event FHF-MTRWPLO-CC2. For collisions, 
a design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design- 
Procedural 
Safety 
12.Equipment drop or collision (including lifting yokes) onto or against 
a loaded, sealed WP in the WP transporter load area (including 
the process to move the WP from the trolley to the WP 
transporter) (Room 1003). 
FHF-MTRWPLO-CC12 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC7. Preventative Procedural 
Safety 
13.Collision involving a WP transporter (holding the sealed WP on a 
pallet) and the doors between the main transfer room and the 
preparation room (Rooms 1002 and 1003). 
FHF-MTRWPLO-CC13 Beyond Category 2 A design requirement ensures that the WP transporter transports the WP in a manner such 
that if a collision or derailment (excluding tipover) occurs, the WP impact energy would be 
low enough to preclude a WP breach. A design requirement ensures that the WP 
transporter transports the WP in a manner such that if a collision or derailment leading to a 
transporter tipover occurs, the WP impact energy would be low enough to preclude a WP 
breach. 
Preventive Design 
14.The doors between the main transfer room and the preparation 
room close on the WP transporter (holding the sealed WP on a 
pallet) (Rooms 1002 and 1003). 
FHF-MTRWPLO-CC14 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventative Design 
15.Collision involving a WP transporter (holding a sealed WP on a 
pallet) and the shield doors between the preparation room and the 
entrance vestibule (Rooms 1001 and 1002). 
FHF-MTRWPLO-CC15 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC13. Preventative Design 
16.Shield doors between the preparation room and the entrance 
vestibule close on the WP transporter (holding the sealed WP on 
a pallet) (Rooms 1001 and 1002). 
FHF-MTRWPLO-CC16 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC14. Preventative Design 
17.Collision involving a WP transporter (holding a sealed WP on a 
pallet) and the doors between the entrance vestibule and the 
ambient air (outside) (Room 1001). 
FHF-MTRWPLO-CC17 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC13. Preventative Design 
18.Doors between the entrance vestibule and the ambient air 
(outside) close on the WP transporter (holding the sealed WP on 
a pallet) (Room 1001). 
FHF-MTRWPLO-CC18 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC14. Preventative Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-141 April 2005 
Table III-28. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Loadout): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
19.Derailment or collision of a WP transporter (holding the sealed 
WP on a pallet) in the main transfer room, preparation room, or 
entrance vestibule followed by a load tipover or fall (Rooms 1001, 
1002, and 1003). 
FHF-MTRWPLO-CC19 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC13. Preventative Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1001, 1002, and 1003). 
FHF-MTRWPLO-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed waste package, therefore this event does not occur 
unless an event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a 
possible outcome of any event that exposes SNF to air. Consequence analyses account 
for the possibility of oxidation, as applicable. 
NA NA 
Explosion-Implosion 1. Hydraulic system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Room 1003). 
FHF-MTRWPLO-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on a trolley (Room 1003). FHF-MTRWPLO-EI2 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the equipment in the WP transporter 
load area of the main transfer room, including the WP collar 
removal machine, the tilting machine, and the WP turntable 
(Rooms 1001, 1002, and 1003). 
FHF-MTRWPLO-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with the main transfer room overhead 
crane (Room 1003). 
FHF-MTRWPLO-FT2 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-FT1. Preventive Design- 
Procedural 
Safety 
3. Electrical fire associated with equipment on the WP transporter, 
including motors to extend the WP transporter bedplate (Rooms 
1001, 1002, and 1003). 
FHF-MTRWPLO-FT3 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-FT1. Preventive Design- 
Procedural 
Safety 
4. Electrical fire associated with the WP transporter locomotive 
(Rooms 1001 and 1002). 
FHF-MTRWPLO-FT4 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-FT1. Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with the WP 
closure transfer trolley (Room 1003). 
FHF-MTRWPLO-FT5 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-FT1. Preventive Design- 
Procedural 
Safety 
6. Transient combustible fire in the main transfer room, preparation 
room, or the entrance vestibule (Rooms 1001, 1002, and 1003). 
FHF-MTRWPLO-FT6 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1001, 1002, and 1003). 
FHF-MTRWPLO-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-142 April 2005 
Table III-28. Disposition of Internal Events That Occur Inside the Fuel Handling Facility (Waste Package Loadout): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1001, 1002, and 1003). 
FHF-MTRWPLO-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
3. Inadvertent opening of the main transfer room shield door, leading 
to a worker exposure (Rooms 1002 and 1003). 
FHF-MTRWPLO-R3 Beyond Category 2 Design requirements and operating procedures ensure that event sequences initiated by 
actions that accidentally expose workers to radiation are not Category 1. 
Preventive Design- 
Procedural 
Safety 
4. Inadvertent opening of the WP transporter shielded enclosure 
doors, leading to a worker exposure (Room 1001). 
FHF-MTRWPLO-R4 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-R3. Preventive Design- 
Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1001, 1002, 
and 1003). 
FHF-MTRWPLO-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a trolley holding a sealed WP derailment 
followed by a load tipover or fall and rearrangement of the WP 
internals (Room 1003). 
FHF-MTRWPLO-F1 Beyond Category 2 Same disposition as Potential Event FHF-MTRWPLO-CC1. Preventive Design 
2. Criticality associated with a drop, slapdown, or collision of a 
sealed WP and a rearrangement of the container internals 
(Room 1003). 
FHF-MTRWPLO-F2 Beyond Category 2 A design requirement ensures that sealed waste packages are designed such that drops, 
collisions, and other handling impacts within their design bases, allowing for rearrangement 
of waste package internals and without credit for burnup, cannot lead to a nuclear criticality. 
Preventive Design 
3. Criticality associated with a WP transporter derailment followed by 
a load tipover or fall and rearrangement of the WP internals 
(Room 1003). 
FHF-MTRWPLO-F3 Beyond Category 2 Same disposition as Potential Events FHF-MTRWPLO-F2 and FHF-MTRWPLO-CC13. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; EI = explosion-implosion; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; MTRWPLO = main transfer room waste package 
loadout; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF. If localized, the middle identifies an activity, room, or area, for example MTRWPLO, and the suffix identifies the 
hazard category and event number, for example CC1. When an event sequence has been evaluated in a GET, that tree is identified in the Disposition of Event column. The specific event tree sequence is noted by the last letter in the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-143 April 2005 
Table III-29. Disposition of Internal Events That Occur Inside the FHF (Loaded Site-specific Cask Removal): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Impact due to horizontal movement of a loaded MSC by the main 
transfer room overhead crane before it is fully removed from the 
canister transfer station (Room 1003). 
FHF-MTRWLOM-CC1 Beyond Category 2 A design requirement ensures that cranes are not capable of exerting sufficient force to 
breach a transportation cask, MSC, waste package, or canister as the result of attempts to 
overcome mechanical constraints. 
Preventative Design 
2. Collision of a loaded MSC from the main transfer room overhead 
crane with the canister transfer station (Room 1003). 
FHF-MTRWLOM-CC2 Beyond Category 2 A design requirement limits speed for crane transfers such that a collision at the maximum 
speed could not breach an MSC, transportation cask, transfer cask, DPC, DOE or naval 
canister, or waste package involved in the transfer. 
Preventive Design 
3. Drop of an MSC inner or outer lid (as applicable) from the fuel 
transfer room overhead crane onto the loaded MSC in the fuel 
transfer bay or main transfer room (as applicable) (Room 1003). 
FHF-MTRWLOM-CC3A 
FHF-MTRWLOM-CC3B 
FHF-MTRWLOM-CC3C 
FHF-MTRWLOM-CC3D 
FHF-MTRWLOM-CC3E 
FHF-MTRWLOM-CC3F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(Bounded by GET-02) Design and operational requirements reduce the drop probability. 
Operational requirements limit the lift height of the inner lid of a transportation cask, sitespecific 
cask, or waste package to ensure that a lid drop onto a DOE SNF canister or DOE 
SNF multicanister overpack in a waste package, transportation cask, or site-specific cask 
that breaches the canister is a beyond Category 2 event sequence. Design and 
operational requirements limit the probability of exceeding the lift height. Canister design 
requirements and the reliability of fabrication processes limit the probability that a DOE 
SNF canister or DOE multicanister overpack is defective. Operational requirements will 
establish permissible lift heights to ensure that a drop of a cask outer lid onto the inner lid 
of a loaded DOE SNF transportation cask or MSC will not breach a DOE SNF canister 
inside. 
Preventative Design- 
Procedural 
Safety 
4. Drop or collision of the transfer port plug from the fuel transfer 
room overhead crane onto or against the inner lid or outer lid of a 
loaded MSC (as applicable) in the fuel transfer bay (Room 1003). 
FHF-MTRWLOM-CC4 Beyond Category 2 Design requirements ensure that portions of a non-ITS SSC which, upon failure, could 
adversely interact with an ITS SSC and prevent its safety function from being performed 
are classified as ITS, redesigned to eliminate the potential unacceptable interaction with 
the identified ITS SSC, or, for seismic interactions, designed to the same seismic DBGM as 
the ITS SSCs subjected to the potential unacceptable interaction. 
Preventative Design 
5. Drop of an MSC inner or outer lid (as applicable) from the main 
transfer room overhead crane onto the loaded MSC in the canister 
transfer station (Room 1003). 
FHF-MTRWLOM-CC5A 
FHF-MTRWLOM-CC5B 
FHF-MTRWLOM-CC5C 
FHF-MTRWLOM-CC5D 
FHF-MTRWLOM-CC5E 
FHF-MTRWLOM-CC5F 
No drop 
Category 2 
No drop 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-02) Same disposition as Potential Event FHF-MTRWLOM-CC3. Preventive Design- 
Procedural 
Safety 
6. Collision of a mobile elevated platform with a loaded MSC during 
docking ring removal activities associated with the MSC (Room 
1003). 
FHF-MTRWLOM-CC6 Beyond Category 2 Operational requirements ensure that the portable platforms, access platforms, 
mobile elevated platforms, and forklifts operated in the facility are not operated in a manner 
that could breach or overturn a loaded transportation cask or site-specific cask. 
Preventative Procedural 
Safety 
7. Collision of a trolley holding a loaded MSC on a pedestal with the 
shield doors separating the fuel transfer bay and the main transfer 
room (Room 1003). 
FHF-MTRWLOM-CC7 Beyond Category 2 (See GET-22) A design requirement limits the speed of trolley movements such that a 
collision at the speed limit would not cause the trolley to drop its load. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-144 April 2005 
Table III-29. Disposition of Internal Events That Occur Inside the FHF (Loaded Site-specific Cask Removal): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
8. Closure of the shield doors separating the fuel transfer bay and 
the main transfer room onto the trolley holding a loaded MSC on a 
pedestal (Room 1003). 
FHF-MTRWLOM-CC8 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventative Design 
9. Drop or collision of tools or equipment (including the outer lidlifting 
fixture, inner lid-lifting fixture [as applicable], lid bolts, etc.) 
onto or against a MSC inner lid or outer lid (as applicable) during 
the MSC sealing process (Room 1003). 
FHF-MTRWLOM-CC9 Beyond Category 2 An operational requirement limits lift heights for tools and equipment associated with 
transportation cask, transfer cask, MSC, and DPC handling and preparation to the 
minimum necessary for operational purposes. The operational requirement ensures that 
tools and equipment, including handling equipment, if dropped from the height limit, can not 
initiate an event sequence if dropped onto or collided against (1) a transportation cask or 
site-specific cask with its outer lid removed and its inner lid in place but unbolted, (2) an 
exposed sealed dual-purpose canister, or (3) a dual-purpose canister with its severed lid in 
place. 
Preventive Procedural 
Safety 
10.Derailment of a trolley serving a fuel transfer bay or the importexport 
trolley holding a loaded MSC on a pedestal followed by a 
load tipover or fall (Room 1003). 
FHF-MTRWLOM-CC10 Beyond Category 2 A design requirement ensures that loaded transfer trolleys do not derail or drop their loads. 
Design requirements apply to trolleys for casks, waste packages, site-specific casks, and 
dual-purpose canisters. 
Preventive Design 
11.Drop of a loaded MSC from the main transfer room overhead 
crane onto the floor during the MSC transfer from a pedestal 
staged on a trolley serving the fuel transfer bay or from the 
canister transfer station to the import-export trolley and pedestal 
(Room 1003). 
FHF-MTRWLOM-CC11A 
FHF-MTRWLOM-CC11B 
FHF-MTRWLOM-CC11C 
FHF-MTRWLOM-CC11D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Design and operational requirements reduce the drop probability. Design 
requirements limit the lift height for transportation and transfer casks without impact limiters 
and site-specific casks. Design and operational requirements limit the probability of 
exceeding the lift height. Canister design requirements and the reliability of fabrication 
processes limit the probability that a DOE SNF canister or DOE multicanister overpack is 
defective. 
Preventive Design- 
Procedural 
Safety 
12.Drop of a loaded MSC from the main transfer room overhead 
crane onto the pedestal on a trolley during the MSC transfer from 
a pedestal staged on a transfer trolley serving the fuel transfer bay 
or from the canister transfer station to the import-export trolley and 
pedestal (Room 1003). 
FHF-MTRWLOM-CC12A 
FHF-MTRWLOM-CC12B 
FHF-MTRWLOM-CC12C 
FHF-MTRWLOM-CC12D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTRWLOM-CC11. Preventive Design- 
Procedural 
Safety 
13.Drop or collision of a loaded MSC from the main transfer room 
overhead crane onto or against a sharp object during the transfer 
from a pedestal staged on a transfer trolley serving the fuel 
transfer bay or from the canister transfer station to the importexport 
trolley and pedestal (Room 1003). 
FHF-MTRWLOM-CC13 Beyond Category 2 Design and operational requirements ensure that surfaces in the load paths through which 
WPs, DOE SNF canisters, naval canisters, DPCs, transportation casks, transfer casks, or 
MSCs are transferred by crane are kept free of structures, such as posts and curbs, that 
could puncture a container in case of a drop. An operational requirement ensures that the 
load paths are kept free of movable puncture hazards. A design requirement limits speed 
for crane transfers such that a collision at the maximum speed could not breach an MSC, 
transportation cask, transfer cask, DPC, DOE or naval canister, or waste package involved 
in the transfer. 
Preventative Design- 
Procedural 
Safety 
14.Slapdown of a loaded MSC following a drop from onto the edge of 
the pedestal or trolley or other object during the transfer from a 
pedestal staged on a transfer trolley serving the fuel transfer bay 
or from the canister transfer station to the import-export trolley and 
pedestal (Room 1003). 
FHF-MTRWLOM-CC14A 
FHF-MTRWLOM-CC14B 
FHF-MTRWLOM-CC14C 
FHF-MTRWLOM-CC14D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTRWLOM-CC11. Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-145 April 2005 
Table III-29. Disposition of Internal Events That Occur Inside the FHF (Loaded Site-specific Cask Removal): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
15.Slapdown of a loaded MSC onto the floor, into a wall, or into 
nearby equipment following a drop from the main transfer room 
overhead crane onto the edge of the import-export trolley, 
pedestal, or other equipment during the lift and transfer of the 
MSC from the canister transfer station to the import-export trolley 
(Room 1002). 
FHF-MTRWLOM-CC15A 
FHF-MTRWLOM-CC15B 
FHF-MTRWLOM-CC15C 
FHF-MTRWLOM-CC15D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTRWLOM-CC11. Preventive Design- 
Procedural 
Safety 
16.Collision of the import-export trolley holding a loaded MSC on a 
pedestal with the shield doors separating the main transfer room 
and the preparation room or the preparation room and the 
entrance vestibule (Rooms 1002 and 1003). 
FHF-MTRWLOM-CC16 Beyond Category 2 (See GET-22) Same disposition as Potential Event FHF-MTRWLOM-CC7. Preventative Design 
17.Closure of the shield doors separating main transfer room and the 
preparation room or the preparation room and the entrance 
vestibule onto the import-export trolley holding a loaded MSC on a 
pedestal (Rooms 1002 and 1003). 
FHF-MTRWLOM-CC17 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-CC8. Preventative Design 
18.Drop or collision of equipment in the preparation room onto or 
against a loaded MSC on a pedestal on an import-export trolley 
(Room 1002). 
FHF-MTRWLOM-CC18 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-CC9. Preventive Procedural 
Safety 
19.Drop of a loaded MSC from the entrance vestibule gantry crane 
onto the floor during the lifting of the loaded MSC off of the 
pedestal on the import-export trolley (Room 1001). 
FHF-MTRWLOM-CC19A 
FHF-MTRWLOM-CC19B 
FHF-MTRWLOM-CC19C 
FHF-MTRWLOM-CC19D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTRWLOM-CC11. Preventive Design- 
Procedural 
Safety 
20.Drop or collision of a loaded MSC from the entrance vestibule 
gantry crane onto or against a sharp object during the lifting of the 
loaded MSC off of the pedestal on the import-export trolley. 
(Room 1001). 
FHF-MTRWLOM-CC20 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-CC13. Preventative Design- 
Procedural 
Safety 
21.Slapdown of a loaded, sealed MSC following a drop from the 
entrance vestibule gantry crane onto the edge of the pedestal, 
edge of the import-export trolley, or other equipment during the 
lifting of the loaded MSC off of the pedestal on the import-export 
trolley (Room 1001). 
FHF-MTRWLOM-CC21A 
FHF-MTRWLOM-CC21B 
FHF-MTRWLOM-CC21C 
FHF-MTRWLOM-CC21D 
Category 2 
No breach 
Beyond Category 2 
Beyond Category 2 
(See GET-01) Same disposition as Potential Event FHF-MTRWLOM-CC11. Preventive Design- 
Procedural 
Safety 
22.Collision of the entrance vestibule gantry crane, holding a loaded 
MSC, with a forklift, mobile elevated platform, or other object in 
the entrance vestibule (Room 1001). 
FHF-MTRWLOM-CC22 Beyond Category 2 Same disposition as Potential Events FHF-MTRWLOM-CC2 and FHF-MTRWLOM-CC6. Preventative Design- 
Procedural 
Safety 
23.Collision of the entrance vestibule gantry crane holding a loaded 
MSC with the entrance vestibule doors (Room 1001). 
FHF-MTRWLOM-CC23 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-CC2. Preventative Design 
24.The entrance vestibule doors close on the entrance vestibule 
gantry crane holding a loaded MSC (Room 1001). 
FHF-MTRWLOM-CC24 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-CC8. Preventative Design 
Chemical Contamination- 
Flooding 
1 Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-CCF1 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed cask, therefore this event does not occur unless an 
event sequence leads to exposure of SNF to air. Oxidation of the fuel matrix is a possible 
outcome of any event that exposes SNF to air. Consequence analyses account for the 
possibility of oxidation, as applicable. 
NA NA
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-146 April 2005 
Table III-29. Disposition of Internal Events That Occur Inside the FHF (Loaded Site-specific Cask Removal): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Explosion-Implosion 1. MSC inerting system (or other pneumatic or pressurized system) 
missile due to a fractured nozzle/valve stem/pneumatic device 
(Room 1003). 
FHF-MTRWLOM-EI1 Beyond Category 2 An operational requirement ensures that pressurized systems that could generate missiles, 
energetic enough to penetrate a transportation cask with or without impact limiters, a 
transfer cask, a DOE canister, a naval SNF canister, a dual-purpose canister, the inner lid 
of a transportation cask, a site-specific cask, a waste package, or the inner lid of a sitespecific 
cask or waste package are not present in areas where potentially vulnerable items 
may be exposed. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on the import-export trolley 
(Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-EI2 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
3. Hydrogen explosion involving batteries on a mobile elevated 
platform (Room 1003). 
FHF-MTRWLOM-EI3 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-EI2. Preventive Procedural 
Safety 
4. Explosion hazard associated with the cask purging system and 
the ignition of hydrogen that may have accumulated in the cask 
prior to MSC purging and inerting (Room 1003). 
FHF-MTRWLOM-EI4 Beyond Category 2 Operational requirements ensure that precautions taken during the cask sampling and 
purging process provide reasonable assurance that such hydrogen explosions would not 
occur. 
Preventative Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the main transfer room overhead 
cranes and the entrance vestibule gantry crane (Rooms 1001, 
1002, and 1003). 
FHF-MTRWLOM-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Electrical fire associated with handling equipment or other 
equipment located in the main transfer room, the preparation 
room, or the entrance vestibule (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-FT2 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-FT1. Preventive Design- 
Procedural 
Safety 
3. Transient combustible fire in the main transfer room, preparation 
room, or the entrance vestibule (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-FT3 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-FT1. Preventive Design- 
Procedural 
Safety 
4. Intact or non-intact SNF overheating due to a loss of cooling 
resulting in excessive temperature and possible zircaloy cladding 
(or other cladding) unzipping or cladding failure due to excessive 
hoop stresses (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-FT4 Beyond Category 2 If ventilation is lost in areas where DOE or naval canisters are handled, no radiological 
release occurs from the canisters because containment within the canisters is maintained. 
Design and operational requirements ensure that the thermal response of areas where 
CSNF assemblies are handled or staged to a loss of HVAC would not cause radiological 
releases in excess of those considered in the consequence analysis for normal operations. 
Preventive Design- 
Procedural 
Safety 
5. Fire/explosion (battery/electrical fire) associated with the importexport 
trolley or MSC trolley (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-FT5 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-FT1. Preventive Design- 
Procedural 
Safety 
6. Fire/explosion (battery/electrical fire) associated with the mobile 
elevated platform (Room 1003). 
FHF-MTRWLOM-FT6 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-FT1. Preventive Design- 
Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-147 April 2005 
Table III-29. Disposition of Internal Events That Occur Inside the FHF (Loaded Site-specific Cask Removal): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Damage or rupture of cask inerting system leading to a release of 
cask internal gases (Room 1003). 
FHF-MTRWLOM-R2 Normal Operations Although a rupture leading to a radiological release would be an off-normal occurrence, any 
release and related dose would be managed as part of routine radiation protection 
operations. Potential exposure of workers to radiation as a result of this event is managed 
as a normal-operations dose by procedures that ensure that workers do not receive 
excessive radiation doses. 
Mitigative Procedural 
Safety 
3. Expansion of gasses in the MSC, leading to radiological release 
(Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-R3 Normal Operations Thermal expansion of gases is to be expected as a part of normal operations. 
Any resulting potential exposure of workers to radiation is managed as a normal-operations 
dose by procedures that ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
4. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-R4 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (Rooms 1001, 1002, 
and 1003). 
FHF-MTRWLOM-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
Fissile 1. Criticality associated with a MSC trolley collision or trolley 
derailment followed by a load tipover or fall and a rearrangement 
of the MSC internals (Rooms 1001, 1002, and 1003). 
FHF-MTRWLOM-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. 
Preventive Design 
2. Criticality associated with a drop or slapdown of a loaded MSC 
from an overhead crane and a rearrangement of cask internals 
(Room 1003). 
FHF-MTRWLOM-F2 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-F1. Preventive Design 
3. Criticality associated with the drop of heavy equipment onto an 
unsealed MSC and a rearrangement of the container internals 
(Room 1003). 
FHF-MTRWLOM-F3 Beyond Category 2 Same disposition as Potential Event FHF-MTRWLOM-F1. Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; EI = explosion-implosion; F = fissile; FHF = Fuel Handling Facility; FT = fire-thermal; GET = generalized event tree; HLW = high-level radioactive waste; MTRWLOM = main transfer room waste loadout sitespecific 
cask; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SRTC = site rail transfer cart. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF, the middle identifies an activity, room, or area, for example MTRWLOM, and the suffix identifies the hazard 
category and event number, for example CC1. When an event sequence has been evaluated in a GET, the GET number is identified in the Disposition of Event column; the GET sequence alpha character is shown at the end of the Event Sequence Designator, for 
example A. 
GETs are discussed in Sections 6.3.1.1 to 6.3.1.24. 
]
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-148 April 2005 
Table III-30. Disposition Internal Events That Occur Inside the Fuel Handling Facility (Empty Site-specific Cask Removal): Main Transfer Room (Room 1003), Preparation Room (Room 1002), Entrance Vestibule (Room 1001) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category 
Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing No potential events identified. 
Chemical Contamination- 
Flooding 
No potential events identified. 
Explosion-Implosion No potential events identified. 
Fire-Thermal No potential events identified. 
Radiation 1. Radiation exposure of a facility worker and/or the offsite public 
(Rooms 1001, 1002, and 1003). 
FHF-EMR-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Loss of confinement zone due to ventilation system malfunction or 
other breach of a confinement barrier leading to a release of 
airborne radiation (Rooms 1001, 1002, and 1003). 
FHF-EMR-R2 NA (no significant 
exposure) 
Operating procedures ensure that a loss of confinement during otherwise normal 
operations does not cause individuals to be exposed to significant amounts of radioactivity. 
Mitigative Procedural 
Safety 
Fissile No potential events identified. 
NOTES: EMR = empty site-specific cask removal; FHF = Fuel Handling Facility; NA = not applicable; R = radiation. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example FHF, the middle identifies an activity, room, or area, for example EMR, and the suffix identifies the hazard category 
and event number, for example CC1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-149 April 2005 
Table III-31. Disposition of Internal Events That Occur During Waste Package Subsurface Transport and Emplacement 
Disposition of Event 
Generic Event Category Potential Event 
Potential Event 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Collision involving the transport locomotive and the WP transporter 
(holding the sealed WP on a pallet) during coupling, prior to 
entering the North Portal (GA). 
SS-TE-CC1 Beyond Category 2 A design requirement ensures that the WP transporter transports the WP in a manner such 
that if a collision or derailment (excluding tipover) occurs, the WP impact energy would be 
low enough to preclude a WP breach. Also, a design requirement ensures that the 
restraints used to immobilize the bedplate inside the shielded compartment of the 
transporter, and the mechanism for locking the doors of the shielded compartment 
withstand a collision or derailment (including tipover) of the transporter without resulting in 
a Category 1 or Category 2 event sequence. A design requirement ensure that the WP 
transporter transports the WP in a manner such that if a collision or derailment leading to a 
transporter tipover occurs, the WP impact energy would be low enough to preclude a WP 
breach. 
Preventative Design 
2. Derailment of a WP transporter outdoors, prior to entering the north 
ramp, followed by a load tipover or fall (GA). 
SS-TE-CC2 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Preventative Design 
3. Derailment of a WP transporter while on the north ramp, in a main 
drift, or in an emplacement drift turnout, after passing through the 
North Portal, followed by a load tipover or fall (GA). 
SS-TE-CC3 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Preventative Design 
4. Runaway of a loaded WP transporter while proceeding down the 
north ramp (GA). 
SS-TE-CC4 Beyond Category 2 A design requirement ensures the WP transporter has design features with reliability goals 
to make the transporter runaway event beyond Category 2. 
Preventative Design 
5. Collision involving a WP transporter (holding a sealed WP on a 
pallet) and other stationary or moving equipment (GA). 
SS-TE-CC5 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Additionally, an operational requirement 
ensures that vehicle crossings of the railway are controlled to ensure that the potential for 
collisions between vehicles and the waste package transporter carrying a loaded waste 
package is minimized. 
Preventative Design- 
Procedural 
Safety 
6. Derailment of a WP transporter at the turnout drift switch, followed 
by a load tipover or fall (GA). 
SS-TE-CC6 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Preventative Design 
7. Collision involving a WP transporter (holding the sealed WP on a 
pallet) and the emplacement access doors (GA). 
SS-TE-CC7 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Preventative Design 
8. Emplacement access doors close on the WP transporter (holding 
the sealed WP on a pallet) (GA). 
SS-TE-CC8 Beyond Category 2 A design requirement ensures that closure of airlock doors, shield doors, and other 
applicable doors on a transfer trolley, site-rail transfer cart (SRTC), MSC transporter, WP 
transporter, would not cause a tipover of the conveyance or cause the conveyance to drop 
its load. A design requirement ensures that closure of airlock doors, shield doors, and 
other applicable doors on a transportation cask, transfer cask, or MSC suspended from an 
overhead crane would not cause the crane to drop its load. 
Preventative Design 
9. Rockfall onto a WP transporter while in the subsurface (GA). SS-TE-CC9 Beyond Category 2 Credible rockfall scenarios are evaluated and found that no damage to the transporters 
shielded compartment occurs in a manner sufficient to jeopardize the structural integrity of 
the waste package. Therefore, a rockfall does not result in a Category 1 or Category 2 
event sequence. 
Preventative Design 
10. Collision involving a WP transporter (holding the sealed WP on a 
pallet) and the emplacement transfer dock (while entering the 
dock) (GA). 
SS-TE-CC10 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Preventative Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-150 April 2005 
Table III-31. Disposition of Internal Events That Occur During Waste Package Subsurface Transport and Emplacement (Continued) 
Disposition of Event 
Generic Event Category Potential Event 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
11.WP transporter doors close on the WP on a pallet (GA). SS-TE-CC11 Beyond Category 2 A design requirement ensures that movement of the transporter shielded enclosure doors 
will not breach the waste package or cause it to fall from the bedplate of the transporter. 
Preventative Design 
12.WP rolls or slides out of a WP transporter on the surface 
(outdoors), in a ramp, in a main drift, or at the entrance of the 
emplacement drift (GA). 
SS-TE-CC12 Beyond Category 2 Same disposition as Potential Event SS-TE-CC1. Also, a design requirement ensures that 
spurious or operator-induced opening of the waste package shielded compartment followed 
by a bedplate rollout is precluded when the transporter is in motion. 
Preventative Design 
13.WP and pallet drop from a WP emplacement gantry (GA). SS-TE-CC13A 
SS-TE-CC13B 
SS-TE-CC13C 
No collision 
No breach 
Beyond Category 2 
(See GET-24) Design and operational requirements on the WP Emplacement Gantry 
reduce the drop probability. Design and operational requirements establish lift-height limits 
for WPs in horizontal orientation on the emplacement pallet. Design and operational 
requirements for the WP Emplacement Gantry limit the conditional probability of exceeding 
the WP lift height. 
Preventative Design- 
Procedural 
Safety 
14. Derailment of a WP emplacement gantry holding a WP on a 
pallet, followed by a load drop (drop of the WP and pallet) (GA). 
SS-TE-CC14A 
SS-TE-CC13B 
SS-TE-CC13C 
No collision 
No breach 
Beyond Category 2 
(see GET-24) Same disposition as Potential Event SS-TE-CC13. Preventative Design- 
Procedural 
Safety 
15.WP emplacement gantry carrying a WP collides with another WP 
in the drift (GA). 
SS-TE-CC15 Beyond Category 2 A design requirement ensures that the WP Emplacement Gantry is limited in speed such 
that it could not cause a waste-package breach in case of a collision. 
Preventative Design 
16.WP emplacement gantry carrying a WP travels to the end of the 
drift and drops off the end of the rails, falling to the ground below 
(GA). 
SS-TE-CC16 Beyond Category 2 A design requirement ensures that the WP Emplacement Gantry, carrying a WP, is not 
capable of running off the end of the emplacement drift or transfer dock rails.. 
Preventative Design 
17.WP emplacement gantry holding a WP on a pallet rolls off the 
emplacement transfer dock and either falls onto the drift rails (or 
surrounding ground) or impacts the WP transporter (if the 
transporter has not been moved) (GA). 
SS-TE-CC17A 
SS-TE-CC13B 
SS-TE-CC13C 
No collision 
No breach 
Beyond Category 2 
(See GET-24) Same disposition as Potential Event SS-TE-CC13. Preventative Design- 
Procedural 
Safety 
18.Empty WP emplacement gantry rolls off the emplacement transfer 
dock and falls onto the WP transporter, impacting the WP on the 
pallet on the extended bedplate (GA). 
SS-TE-CC18 Beyond Category 2 Design and operational requirements ensure that if the gantry falls onto the transporter and 
impacts the waste package, it does not cause the waste package to be breached. 
Preventative Design- 
Procedural 
Safety 
19. Collision of a WP emplacement gantry, holding a WP, on a pallet 
with a fallen rock, fallen ground support, or other object, followed 
by a load drop (drop of the WP and pallet) (GA). 
SS-TE-CC19 Beyond Category 2 Same disposition as Potential Event SS-TE-CC15. Preventative Design 
20. Rockfall onto a WP (GA). SS-TE-CC20 Beyond Category 2 In the emplacement drifts, credible rockfall scenarios do not damage the waste package 
in a manner sufficient as to jeopardize its structural integrity. Therefore, rockfalls do not 
initiate a Category 1 or Category 2 event sequence. 
Preventative Design 
21. Rockfall onto a WP emplacement gantry holding a WP on a pallet 
(GA). 
SS-TE-CC21 Beyond Category 2 Same disposition as Potential Event SS-TE-CC20. Preventative Design 
22. Ground support drop onto a WP (GA). SS-TE-CC22 Beyond Category 2 The consequences of failed ground support components falling on the waste package 
would not be more severe than those resulting from credible rockfall scenarios, which do 
not damage the waste package in a manner sufficient to jeopardize its structural integrity. 
The event does not initiate a Category 1 or Category 2 event sequence. 
Preventative Design 
23. Ground support drop onto a WP emplacement gantry holding a 
WP on a pallet (GA). 
SS-TE-CC23 Beyond Category 2 Same disposition as Potential Event SS-TE-CC22. Preventative Design 
24.Runaway WP transporter in an access main and a collision with 
the barrier isolating the development side of the repository from 
the emplacement side of the repository (GA). 
SS-TE-CC24 Beyond Category 2 Same disposition as Potential Event SS-TE-CC4. Preventative Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-151 April 2005 
Table III-31. Disposition of Internal Events That Occur During Waste Package Subsurface Transport and Emplacement (Continued) 
Disposition of Event 
Generic Event Category Potential Event 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Chemical Contamination- 
Flooding 
1. Flooding from a water pipe break originating on the development 
side of the repository (GA). 
SS-TE-CCF1 Beyond Category 2 Operational requirements ensure that construction operations are sufficiently isolated from 
surface and subsurface repository operations to preclude interactions with waste receipt, 
handling, emplacement, or retrieval operations. 
Preventative Procedural 
Safety 
2. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures or during off-normal conditions, 
(e.g., during a failure of the emplacement ventilation subsystem) 
(GA). 
SS-TE-CCF2 NAAccounted for in 
consequence 
analyses, if applicable 
NASNF is contained inside a sealed waste package, therefore this event does not occur 
unless an event sequence leads to exposure of SNF to air. There are no Category 1 or 
Category 2 event sequences underground. 
NA NA 
Explosion-Implosion 1. Hydrogen explosion involving batteries on the transport 
locomotive (GA). 
SS-TE-EI1 Beyond Category 2 Operational controls pertaining to batteries for powering heavy equipment ensure the 
generation or accumulation of enough hydrogen gas to cause an explosion that could 
breach a transportation cask, site-specific cask, or waste package is prevented. 
Preventive Procedural 
Safety 
2. Hydrogen explosion involving batteries on the WP emplacement 
gantry (GA). 
SS-TE-EI2 Beyond Category 2 Same disposition as Potential Event SS-TE-EI1. Preventative Procedural 
Safety 
Fire-Thermal 1. Electrical fire associated with the transport locomotive (GA). SS-TE-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventative Design 
Procedural 
Safety 
2. Fire/explosion (battery/electrical fire) associated with the transport 
locomotive (GA). 
SS-TE-FT2 Beyond Category 2 Same disposition as Potential Event SS-TE-FT1. Preventative Design 
Procedural 
Safety 
3. Fire/explosion (battery/electrical fire) associated with the WP 
emplacement gantry (GA). 
SS-TE-FT3 Beyond Category 2 Same disposition as Potential Event SS-TE-FT1. Preventative Design 
Procedural 
Safety 
4. Electrical fire associated with equipment on the WP transporter, 
including motors to extend the WP transporter bedplate (GA). 
SS-TE-FT4 Beyond Category 2 Same disposition as Potential Event SS-TE-FT1. Preventative Design 
Procedural 
Safety 
5. Electrical fire associated with the WP emplacement gantry or 
other subsurface equipment (GA). 
SS-TE-FT5 Beyond Category 2 Same disposition as Potential Event SS-TE-FT1. Preventative Design 
Procedural 
Safety 
6. WP overheating in the WP transporter due to solar insolation 
while stalled or stopped outdoors during transit from a surface 
facility to the subsurface facility (GA). 
SS-TE-FT6 Beyond Category 2 Results of calculations evaluating the maximum temperature of the waste package show 
that the waste package does not lose its structural integrity due to solar insolation while 
stalled or stopped outdoors. This event does not initiate a Category 1 or Category 2 event 
sequence. 
Preventative Design 
7. Extended loss of the subsurface ventilation system (GA). SS-TE-FT7 Beyond Category 2 The thermal effects of a loss of emplacement-drift ventilation have been examined and this 
event does not initiate a Category 1 or Category 2 event sequence as a result of a loss of 
ventilation. 
Preventative Design 
Radiation 1. Radiation exposure of a facility worker and/or the offsite 
public (GA). 
SS-TE-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
2. Early WP failure while in the subsurface during the preclosure 
period and a resultant release of radioactive material (GA). 
SS-TE-R2 Beyond Category 2 No significant degradation of a defective waste package takes place during the 100-year 
preclosure period. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-152 April 2005 
Table III-31. Disposition of Internal Events That Occur During Waste Package Subsurface Transport and Emplacement (Continued) 
Disposition of Event 
Generic Event Category Potential Event 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Release of activated air and dust to the environment (GA). SS-TE-R3 Normal Operations Activated air and dust are continuously released into the environment by the subsurface 
ventilation system and are a part of normal operations. Resulting exposure of workers to 
radiation is managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation 
doses. 
Mitigative Procedural 
Safety 
4. Inadvertent opening of the WP transporter shielded enclosure 
doors, leading to a worker exposure (GA). 
SS-TE-R4 Beyond Category 2 Design and operational requirements ensure that exposure of workers due to inadvertent 
actuation of shield doors or pit protective covers is not Category 1. 
Preventive Design- 
Procedural 
Safety 
5. Radiation-induced damage to a facility SSC (GA). SS-TE-R5 NA Radiation-induced damage to a facility SSC is not a separate event for the purposes of 
categorization. 
NA NA 
6. Inadvertent opening of the emplacement access doors leading to 
a worker exposure (GA). 
SS-TE-R6 Beyond Category 2 Same disposition as Potential Event SS-TE-R4. Preventive Design- 
Procedural 
Safety 
Fissile 1. Criticality associated with a drop or collision of a WP and a 
rearrangement of the container internals (GA). 
SS-TE-F1 Beyond Category 2 A design requirement ensures that sealed waste packages are designed so that drops, 
collisions, and other handling impacts, within their design bases cannot lead to a nuclear 
criticality, allowing for rearrangement of waste package internals, proximity of the waste 
package and without credit for burnup. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; EI = explosion-implosion; FT = fire-thermal; GA = general area; GET = generalized event tree; NA = not applicable; R = radiation; SNF = spent nuclear fuel; SS = subsurface; TE = transport and 
emplacement. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example SS. If localized, the middle identifies an activity, room, or area, for example TE, and the suffix identifies the hazard 
category and event number, for example CC1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-153 April 2005 
Table III-32. Disposition of Internal Events That Occur During Subsurface Construction 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing No potential events identified. 
Chemical Contamination- 
Flooding 
1. Flooding from a pipe break originating on the development side of 
the repository. 
SUBC-GA-CCF1 Beyond Category 2 Operational requirements ensure that construction operations are sufficiently isolated from 
surface and subsurface repository operations to preclude interactions with waste receipt, 
handling, emplacement, or retrieval operations. 
Preventive Procedural 
Safety 
Explosion-Implosion No potential events identified. 
Fire-Thermal 1. Diesel fuel fire/explosion associated with subsurface 
development equipment resulting in damage to the subsurface 
isolation barriers. 
SUBC-GA-FT1 Beyond Category 2 Same disposition as Potential Event SUBC-GA-CCF1. Preventive Procedural 
Safety 
2. Electrical fire associated with subsurface development equipment 
or other equipment resulting in damage to the subsurface 
isolation barriers. 
SUBC-GA-FT2 Beyond Category 2 Same disposition as Potential Event SUBC-GA-CCF1. Preventive Procedural 
Safety 
3. Transient combustible fire in the development side of the 
subsurface facilities resulting in damage to the subsurface 
isolation barriers. 
SUBC-GA-FT3 Beyond Category 2 Same disposition as Potential Event SUBC-GA-CCF1. Preventive Procedural 
Safety 
Radiation No potential events identified. 
Fissile No potential events identified. 
NOTES: CCF = chemical-contamination flooding; FT = fire-thermal; SUBC = subsurface construction. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example SUBC, the middle identifies an activity, room, or area, for example GA, and the suffix identifies the hazard category 
and event number, for example CCF1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-154 April 2005 
Table III-33. Disposition of Internal Events That Occur During Surface Construction 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Impacts on a loaded transportation cask, a loaded MSC, or a 
loaded WP as a result of construction operations (GA). 
SC-GA-CC1 Beyond Category 2 Operational requirements ensure that construction operations are sufficiently isolated from 
surface and subsurface repository operations to preclude proximity interactions with waste 
receipt, handling, emplacement, or retrieval operations. 
Preventative Procedural 
Safety 
Chemical Contamination- 
Flooding 
No potential events identified. 
Explosion-Implosion No potential events identified 
Fire-Thermal 1. Diesel fuel fire/explosion associated with construction 
equipment (GA). 
SC-GA-FT1 Beyond Category 2 Same disposition as Potential Event SC-GA-CC1. Preventive Procedural 
Safety 
2. Electrical fire associated with construction equipment or other 
equipment (GA). 
SC-GA-FT2 Beyond Category 2 Same disposition as Potential Event SC-GA-CC1. Preventive Procedural 
Safety 
3. Transient combustible fire (GA). SC-GA-FT3 Beyond Category 2 Same disposition as Potential Event SC-GA-CC1. Preventive Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker and/or the offsite 
public (GA). 
SC-GA-R1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
Fissile 1. Criticality associated with an impact on a loaded transportation 
cask, a loaded MSC, or a loaded WP and a rearrangement of the 
container internals (GA). 
SC-GA-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure that transportation casks, 
transfer casks, MSCs, and dual-purpose canisters (DPCs) are designed to ensure nuclear 
criticality safety with optimum moderation and most-reactive waste forms. Criticality safety 
will be maintained despite geometric rearrangements due to a drop or other handling 
incident. A design requirement ensures that sealed waste packages are designed such 
that drops, collisions, and other handling impacts within their design bases, allowing for 
rearrangement of cask internals, proximity of other sealed waste packages and without 
credit for burnup, cannot lead to a nuclear criticality. 
Preventive Design 
NOTES: CC = collision-crushing; F = fissile; FT = fire-thermal; GA = general area; HLW = high-level radioactive waste; NA = not applicable; R = radiation; SC = surface construction; SNF = spent nuclear fuel. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example SC, the middle identifies an activity, room, or area, for example GA, and the suffix identifies the hazard category and 
event number, for example CC1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-155 April 2005 
Table III-34. Disposition of Internal Events That Occur During Subsurface Drip Shield Installation 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Derailment of a drip shield emplacement gantry carrying a drip 
shield, followed by a load drop (drop of the drip shield); the drip 
shield and/or the gantry impacts a WP or several WPs. 
SS-DS-CC1 Beyond Category 2 The designs of the drip shield and its emplacement gantry ensure that it is not physically 
possible for the drip shield or drip-shield emplacement gantry to contact the waste package 
during installation. 
Preventive Design 
2. Drip shield emplacement gantry carrying a drip shield collides with 
a WP or WPs due to gantry failure. 
SS-DS-CC2 Beyond Category 2 Same disposition as Potential Event SS-DS-CC1. Preventive Design 
3. Collision of a drip shield emplacement gantry, holding a drip 
shield, with a fallen rock, fallen ground support, or other object, 
followed by a load drop (drop of the drip shield) onto a WP or 
WPs. 
SS-DS-CC3 Beyond Category 2 Same disposition as Potential Event SS-DS-CC1. Preventive Design 
4. Rockfall onto a drip shield emplacement gantry carrying a drip 
shield, leading to gantry damage or failure and impact of the rock 
or drip shield with a WP. 
SS-DS-CC4 Beyond Category 2 Same disposition as Potential Event SS-TE-CC20. Rockfall scenarios do not initiate a 
Category 1 or Category 2 event sequence. 
Preventive Design 
5. Rockfall onto a WP. SS-DS-CC5 Beyond Category 2 Same disposition as Potential Event SS-DS-CC4. Preventive Design 
6. Ground support drop onto a WP. SS-DS-CC6 Beyond Category 2 Same disposition as Potential Event SS-TE-CC22. The event does not initiate a Category 
1 or Category 2 event sequence. 
Preventive Design 
7. Ground support drop onto a drip shield emplacement gantry 
carrying a drip shield, leading to gantry damage or failure and 
impact of the ground support or drip shield with a WP. 
SS-DS-CC7 Beyond Category 2 Same disposition as Potential Event SS-DS-CC6. Preventive Design 
Chemical Contamination- 
Flooding 
1. Non-intact SNF oxidation or oxidation of damaged SNF and 
degradation due to exposure to a non-inerted environment at 
normal operating temperatures or during off-normal conditions 
(e.g., during a failure of the emplacement ventilation subsystem.) 
SS-DS-CCF1 NA SNF is contained inside a sealed waste package, therefore SNF is not exposed to air and 
this event does not occur. 
NA NA 
Explosion-Implosion No potential events identified 
Fire-Thermal 1. Electrical fire associated with the drip shield emplacement gantry 
or other subsurface equipment. 
SS-DS-FT1 Beyond Category 2 Design and operational requirements ensure control of the presence and amount of 
combustibles in the different areas of the repository to preclude any Category 1 or 
Category 2 event sequences potentially initiated by a fire. 
Preventive Design- 
Procedural 
Safety 
2. Loss of the subsurface ventilation system. SS-DS-FT2 Beyond Category 2 The thermal effects of a loss of emplacement-drift ventilation have been examined and this 
event does not initiate a Category 1 or Category 2 event sequence as a result of a loss of 
ventilation. 
Preventive Design 
Radiation 1. Early WP failure while in the subsurface during the preclosure 
period and a resultant release of radioactive material. 
SS-DS-R1 Beyond Category 2 No significant degradation of a defective waste package takes place during the 100-year 
preclosure period. 
Preventive Design 
2. Release of activated air and dust to the environment. SS-DS-R2 Normal Operations Activated air and dust are continuously released into the environment by the subsurface 
ventilation system and is a part of normal operations. Resulting exposure of workers to 
radiation is managed as a normal-operations dose by procedures for monitoring radiation 
doses and assigning work, which ensure that workers do not receive excessive radiation 
doses. 
Mitigative Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-156 April 2005 
Table III-34. Disposition of Internal Events That Occur During Subsurface Drip Shield Installation (Continued) 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Fissile 1. Criticality associated with an impact or collision with a WP and a 
rearrangement of the container internals. 
SS-DS-F1 Beyond Category 2 A design requirement ensures that sealed waste packages are designed such that drops, 
collisions, and other handling impacts within their design bases, allowing for rearrangement 
of waste package internals, proximity of other sealed waste packages and without credit for 
burnup, cannot lead to a nuclear criticality. 
Preventive Design 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; DS = drip shield; F = fissile; FT = fire-thermal; NA = not applicable; R = radiation; SS = subsurface; SNF = spent nuclear fuel. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building/facility, for example SS, the middle identifies an activity, room, or area, for example DS, and the suffix identifies the hazard category and 
event number, for example CC1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-157 April 2005 
Table III-35. Disposition of Internal Events That Occur During Disposal of Low-Level Radioactive Waste 
Disposition of Event 
Generic Event Category Potential Event (Room or Area) 
Event Sequence 
Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Drop of a heavy load onto a tank, piping, or a container containing 
liquid or solid radioactive waste (GA). 
LLW-GA-CC1 Normal Operations Minor radioactive releases are expected as a part of normal operations. Any resulting 
potential exposure of workers to radiation is managed as a normal-operations dose by 
procedures for monitoring radiation doses and assigning work, which ensure that workers 
do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
2. Drop of a container or drum containing solid low level radioactive 
waste (LLW) (GA). 
LLW-GA-CC2 Normal Operations Same disposition as Potential Event LLW-GA-CC1. Mitigative Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Drop of a container or drum containing liquid LLW (GA). LLW-GA-CCF1 Normal Operations Same disposition as Potential Event LLW-GA-CC1. Mitigative Procedural 
Safety 
2. Release of radioactive gas from the gas filtration systems or 
cavity gas sampling systems, WP evacuating and inerting 
systems, cask evacuating and inerting systems, or the system 
involved with the cooling of casks prior to immersion in the DTF 
remediation area pool (GA). 
LLW-GA-CCF2 Normal Operations Minor release of gases from these operations is to be expected as a part of normal 
operations. Any resulting potential exposure of workers to radiation is managed as a 
normal-operations dose by procedures for monitoring radiation doses and assigning work, 
which ensure that workers do not receive excessive radiation doses. 
Mitigative Procedural 
Safety 
Explosion-Implosion No potential events identified. 
Fire-Thermal 1. Transient combustible fire in areas where dry, flammable low level 
radioactive waste is stored (GA). 
LLW-GAFT1 Beyond Category 2 Operational requirements provide a control program ensuring that any fire that may occur 
in areas where low level radioactive waste forms are stored will not be of intensity, 
duration, or magnitude to initiate an event sequence. 
Preventive Procedural 
Safety 
Radiation 1. Radiation exposure of a facility worker (GA). LLW-GAR1 NAAccounted for in 
consequence 
analyses, if applicable 
Normal Operations 
NAPotential exposure of workers or the public to radiation is a hazard for the event 
sequences considered in this analysis. Consequence analyses evaluate this hazard for 
Category 1 and Category 2 event sequences, as applicable. 
Some exposure to radiation is expected as a part of normal facility operations. Exposures 
are managed by design features and procedures that ensure that workers or the public do 
not receive excessive radiation doses. 
NA 
Mitigative 
NA 
Design- 
Procedural 
Safety 
Fissile No potential events identified. 
NOTES: CC = collision-crushing; CCF = chemical-contamination flooding; FT = fire-thermal; GA = general area; LLW = low-level radioactive waste processing area; NA = not applicable; R = radiation. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example LLW, the middle identifies an activity, room, or area, for example GA, and the suffix identifies the hazard category and 
event number, for example CC1.
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-158 April 2005 
Table III-36. Disposition of Internal Events That Occur in the Spent Nuclear Fuel Aging System: Vertical Aging Systems 
Disposition of Event 
Generic Event Type Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Failure of the site-specific cask transporter during transfer of a 
vertical cask and the vertical cask drops resulting in damage to 
the aging system (AP, RW, and SF). 
SNFAS-VAS-CC1 Beyond Category 2 Design requirements ensure that site-specific casks can withstand a drop from the 
maximum handling height of a site-specific cask transporter/horizontal transfer cask trailer 
without breach. A design requirement limits site-specific cask/horizontal transfer cask 
maximum potential drop height. 
Preventive Design 
2. Failure of the site-specific cask transporter during transfer of a 
vertical cask and the site-specific cask transporter tips over 
resulting in damage to the aging system (AP, RW, and SF). 
SNFAS-VAS-CC2 Beyond Category 2 Design requirements preclude tip-over during transfer by ensuring that transfer equipment 
design precludes failure modes that could result in tip-over under design basis load 
handling conditions. 
Preventive Design 
3. Failure of the roadway surface during transfer of a vertical cask 
results in a site-specific cask transporter tip-over and damage to 
aging system (RW). 
SNFAS-VAS-CC3 Beyond Category 2 Design requirements preclude tip-over during transfer by ensuring minimum tip-over 
resistance/stability standards are maintained consistent with roadway design. 
Preventive Design 
4. Misdirection of the site-specific cask transporter off edge of 
roadway/pad surface during transfer of a vertical cask causing 
damaged in a tip-over event (AP and RW). 
SNFAS-VAS-CC4 Beyond Category 2 Design requirements limit the size, mass, maximum speed and motive force of vehicles to 
limit potential damage caused by collisions from initiating an event sequence. Design 
requirements ensure reliable means to stop and maintain stability. 
Preventive Design 
5. Collision of the site-specific cask transporter with vehicles or 
equipment staged or moving along transfer route causing direct 
damage, a cask drop, or tip-over event (AP and RW). 
SNFAS-VAS-CC5 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-CC4. Preventive Design 
6. Collision of the site-specific cask transporter with aging cask or 
module staged on aging pad causing direct damage, a cask drop, 
or tip-over event (AP). 
SNFAS-VAS-CC6 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-CC4. Preventive Design 
7. Collision of the site-specific cask transporter following mechanical 
failure that results in runaway and the site-specific cask 
transporter rolls down inclined roadway and collides with fixed 
object or tips over (RW). 
SNFAS-VAS-CC7 Beyond Category 2 Design requirements ensure reliable means to stop and maintain stability such that no 
Category 1 or Category 2 event sequence occurs. 
Preventive Design 
8. Misdirection of the site-specific cask transporter off of the edge 
of the aging pad resulting in a tip-over and damage to aging 
cask (AP). 
SNFAS-VAS-CC8 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-CC4. Preventive Design 
9. Collision of the aging pad maintenance/surveillance vehicle with 
an aging cask or module staged on aging pad during 
maintenance/ surveillance activity on aging pad causing direct 
damage to an aging cask, or tip-over event (AP). 
SNFAS-VAS-CC9 Beyond Category 2 Operational requirements limit aging pad maintenance/surveillance vehicle maximum 
speed and motive force to limit potential damage caused by collisions involving such 
vehicles from initiating an event sequence. 
Preventive Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Chemical spill following collision of the site-specific cask 
transporter with a staged cask system, a SSC, or a site vehicle 
causing an acid spill (i.e., batteries). Acid or other chloride 
containing chemical contact with aging system surface results in 
damage to the aging system (e.g., stainless steel stress corrosion 
cracking). Collisions with other vehicles (security vehicles, etc.) or 
a structure, system, or component could also initiate the same 
event sequence (AP, RW, and SF). 
SNFAS-VAS-CCF1 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-CC4. Additionally, operational 
requirements restrict staging or operation of vehicles along the transfer route or on aging 
pad during transfer operations. Operational requirements implement spill prevention and 
cleanup procedures. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-159 April 2005 
Table III-36. Disposition of Internal Events That Occur in the Spent Nuclear Fuel Aging System: Vertical Aging Systems (Continued) 
Disposition of Event 
Generic Event Type Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
2. Chemical spill following collision an aging pad maintenancesurveillance 
vehicle with a cask system, a structure, system, or 
component, or a site vehicle causing an acid spill (i.e., batteries). 
Acid or other liquid chemical contact with aging system surface 
results in damage to the aging system (e.g., stainless steel stress 
corrosion cracking) (AP). 
SNFAS-VAS-CCF2 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-CC9. Additionally, operational 
requirements implement spill prevention and cleanup procedures. 
Operational requirements limit the presence of combustible and flammable materials 
stored near or used by the SNF aging system structures, systems, or components, 
including those along the transfer route. 
Preventive Procedural 
Safety 
Explosion-Implosion 1. Explosion and/or fire following collision of the site-specific cask 
transporter with a staged cask system, a structure, system, or 
component, or a site vehicle causing a volatile fuel or hydraulic 
fluid spill, or hydrogen release (i.e., batteries). Collisions with 
other vehicles (security vehicles, etc.) or a structure, system, or 
component could also initiate the same event sequence (AP, RW, 
and SF). 
SNFAS-VAS-EI1 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-CC4. Additionally, design 
requirements ensure casks are capable of withstanding limited hydrogen explosions or 
fires involving batteries or limited quantities of fuel without loss of cask function. 
Operational requirements limit the presence of combustible and flammable materials 
stored near or used by the SNF aging system structures, systems, and components, 
including those along the transfer route. 
Preventive Design- 
Procedural 
Safety 
2. Explosion and/or fire following collision of an aging pad 
maintenance/surveillance vehicle with aging cask or module 
causing a volatile fuel or hydraulic fluid spill, or hydrogen release 
(i.e., batteries) (AP). 
SNFAS-VAS-EI2 Beyond Category 2 Operational requirements limit aging pad maintenance/surveillance vehicle maximum 
speed and motive force to limit potential damage caused by collisions involving such 
vehicles from initiating an event sequence. Design requirements ensure casks are capable 
of withstanding limited hydrogen explosions or fires involving batteries or limited quantities 
of fuel without loss of cask function. Operational requirements limit the presence of 
combustible and flammable materials stored near or used by the SNF aging system 
structures, systems, and components, including those along the transfer route. 
Preventive Design- 
Procedural 
Safety 
3. Explosion and/or fire due to welding or cutting activity for cask 
system specific operation (i.e., seismic restraint, vent bird screen, 
radiation shield, or security feature installation-removal) or 
maintenance activity requiring welding/cutting ignites volatile fuel 
or combustibles in the area (AP). 
SNFAS-VAS-EI3 Beyond Category 2 Operational requirements ensure walk-downs are conducted and explosive materials are 
removed from the area prior to initiating welding activities and require safety training as 
part of welder qualification program. 
Preventive Procedural 
Safety 
4. Explosion and/or fire due to gas cylinder drop, crush, or tip over 
during cask system specific operation (i.e., seismic restraint, vent 
bird screen, radiation shield, or security feature installationremoval) 
or maintenance activity requiring welding/cutting (AP). 
SNFAS-VAS-EI4 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-EI3. Additionally, operational 
requirements ensure welding gas cylinders are properly secured and protected from 
damage when located near SNF aging system structures, systems, and components 
containing SNF or HLW. 
Preventive Procedural 
Safety 
Fire-Thermal 1. Transient combustible fire from flammable liquids or combustible 
materials staged on or near the aging pad ignited by unspecified 
ignition source and burn (AP, RW, and SF). 
SNFAS-VAS-FT1 Beyond Category 2 Operational requirements limit the presence of combustible and flammable materials 
stored near or used by the SNF Aging System SSCs, including along the transfer route. 
This ensures that the intensity, duration and magnitude of any fire will not be significant 
enough to initiate a damaged aging cask event sequence. 
Preventive Procedural 
Safety 
2. Malfunction of vent temperature monitoring system results in loss 
of indication or inaccurate monitoring data being observed and 
interpreted by surveillance personnel. Inaccurate monitoring data 
results in a misloaded aging system not being detected and 
damage to contained SNF clad or HLW packaging barriers (AP). 
SNFAS-VAS-FT2 Beyond Category 2 Operational surveillance requirements for monitoring inlet and outlet vent temperature alert 
operators to monitoring system anomaly and initiate corrective actions. 
Preventive Procedural 
Safety 
3. Incorrect use or improper installation of inlet and/or outlet vent 
screens results in inadequate ventilation air flow through aging 
system and damage to contained SNF clad or HLW packaging 
barriers (AP). 
SNFAS-VAS-FT3 Beyond Category 2 Operational requirements provide administrative controls on aging system hardware 
configuration management and require training of aging system workers on specific tasks 
and checking of work performed to minimize potential for installation errors. 
Operational surveillance requirements for monitoring inlet and outlet vent temperature alert 
operators to monitoring system anomaly and initiate corrective actions. 
Preventive Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-160 April 2005 
Table III-36. Disposition of Internal Events That Occur in the Spent Nuclear Fuel Aging System: Vertical Aging Systems (Continued) 
Disposition of Event 
Generic Event Type Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
4. Incorrect installation or defective vent temperature monitoring 
system component(s) results in inaccurate monitoring data being 
observed and interpreted by surveillance personnel. Inaccurate 
monitoring data results in a misloaded aging system not being 
detected and damage to contained SNF clad or HLW packaging 
barriers (AP). 
SNFAS-VAS-FT4 Beyond Category 2 Same disposition as Potential Event SNFAS-VAS-FT3. Additionally, operational 
requirements include start-up testing and calibration of newly installed instrumentation 
required to monitor thermal heat transfer performance of aging casks. 
Preventive Procedural 
Safety 
Radiation 1. Incorrect or malfunctioning confinement barrier monitoring system 
component(s) on bolted closure aging system results in inaccurate 
monitoring data being observed and interpreted by surveillance 
personnel. Inaccurate monitoring data results in a defective aging 
system seal not being detected and unmonitored radiological 
releases to occur (AP). 
SNFAS-VAS-R1 Beyond Category 2 Operational requirements provide administrative controls on aging system hardware 
configuration management and require training of aging system workers on specific tasks 
and checking of work performed to minimize potential for installation errors. Operational 
requirements include start-up testing and calibration of newly installed instrumentation 
required to monitor confinement system performance of bolted closure aging casks. 
Operational surveillance requirements for monitoring confinement systems alert operators 
to monitoring system anomaly and initiate corrective actions. 
Preventive Procedural 
Safety 
2. Malfunction of confinement monitoring system results in loss of 
indication or inaccurate monitoring data being observed and 
interpreted by surveillance personnel. Inaccurate monitoring data 
results in a defective aging system seal not being detected and 
unmonitored radiological releases to occur (AP). 
SNFAS-VAS-R2 Beyond Category 2 Operational surveillance requirements for monitoring confinement systems alert operators 
to monitoring system anomaly and initiate corrective actions. 
Preventive Procedural 
Safety 
3. Failure of primary confinement boundary seal welds for welded 
closure cask systems caused by mechanical loads on system 
(from thermal stress, cask drop, or some other hazard) (AP). 
SNFAS-VAS-R3 Beyond Category 2 Design requirements ensure welded closure casks/canister confinement system design 
precludes loss of confinement during life cycle operations and events following closure. 
Operational requirements minimize the potential for mechanical damage to the SNF aging 
system structure, system, or component cask closure systems. 
Preventive Design- 
Procedural 
Safety 
4. Failure of primary inner lid confinement boundary o-ring seals for 
bolted closure cask systems caused by mechanical damage to the 
closure system (from cask drop or some other hazard) (AP). 
SNFAS-VAS-R4 Beyond Category 2 Design requirements ensures the bolted closure casks design protects seals from damage 
during life cycle operations and events following closure to maintain its primary 
confinement boundary function. Operational requirements minimize the potential for 
mechanical damage to the SNF aging system structure, system, or component cask 
closure systems. 
Preventive Design- 
Procedural 
Safety 
Fissile 1. Criticality associated with a collision or drop of a site-specific cask 
and a rearrangement of the cask internals (AP, RW, and SF). 
SNFAS-VAS-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure criticality safety in 
transportation casks, transfer casks, site-specific casks, and dual-purpose canisters even 
with most reactive credible configuration of fissile material and with optimal moderation. 
Preventive Design 
NOTES: AP = aging pad 17A to 17J; CC = collision-crushing; CCF = chemical contamination flooding; EI = explosion-implosion; F = fissile; FT = fire-thermal; HLW = high-level radioactive waste; R = radiation; RW = roadway to and from the aging pads; SF = surface facilities 
delivering or receiving aging casks; SNF = spent nuclear fuel; SNFAS = spent nuclear fuel aging system; VAS = vertical cask aging systems. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies a building or facility, for example SNFAS, the middle identifies an activity, room, or area, for example VAS, and the suffix identifies the hazard category 
and event number, for example CC1. 
Source: Cogema 2004 [DIRS 171793]
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-161 April 2005 
Table III-37. Disposition of Internal Events That Occur in the SNF Aging System: Horizontal Aging Systems 
Disposition of Event 
Generic Event Type Potential Event (Room or Area) 
Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety, or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
Collision-Crushing 1. Failure of the horizontal transfer cask transfer trailer/tractor 
during transfer of a horizontal transfer cask and the horizontal 
transfer cask drops resulting in damage to the aging system (AP, 
RW, and SF). 
SNFAS-HAS-CC1 Beyond Category 2 Design requirements ensure that site-specific casks can withstand a drop from the 
maximum handling height of a site-specific cask transporter/horizontal transfer cask trailer 
without breach. A design requirement limits site-specific cask/horizontal transfer cask 
maximum potential drop height. 
Preventive Design 
2. Failure of the horizontal transfer cask transfer trailer/tractor during 
transfer of a horizontal transfer cask and the horizontal transfer 
cask transfer trailer/tractor tips over resulting in damage to the 
aging system (AP, RW, and SF). 
SNFAS-HAS-CC2 Beyond Category 2 Design requirements preclude tip-over during transfer by ensuring that transfer equipment 
design precludes failure modes that could result in tip-over under design basis load 
handling conditions. 
Preventive Design 
3. Failure of the Roadway surface during transfer of a horizontal 
transfer cask results in a horizontal transfer cask transfer 
trailer/tractor tip-over and damage to aging system (RW). 
SNFAS-HAS-CC3 Beyond Category 2 Design requirements preclude tip-over during transfer by ensuring minimum tip-over 
resistance/stability standards are maintained consistent with roadway design. 
Preventive Design 
4. Misdirection of the horizontal transfer cask transfer trailer/tractor 
off edge of roadway/pad surface during transfer of a vertical cask 
causing damaged in a tip-over event (AP and RW). 
SNFAS-HAS-CC4 Beyond Category 2 Design requirements limit the size, mass, maximum speed and motive force of vehicles to 
limit potential damage caused by collisions from initiating an event sequence. Design 
requirements ensure reliable means to stop and maintain stability. 
Preventive Design 
5. Collision of the horizontal transfer cask transfer trailer/tractor with 
vehicles or equipment staged or moving along transfer route 
causing direct damage, a cask drop, or tip-over event (AP 
and RW). 
SNFAS-HAS-CC5 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC4. Preventive Design 
6. Collision of the horizontal transfer cask transfer trailer/tractor with 
aging cask or module staged on aging pad causing direct 
damage, a cask drop, or tip-over event (AP). 
SNFAS-HAS-CC6 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC4. Preventive Design 
7. Collision of the horizontal transfer cask transfer trailer/tractor 
following mechanical failure or tow attachment failure that results 
in horizontal transfer cask transfer trailer runaway and the trailer 
rolls down inclined roadway and collides with fixed object or tips 
over (RW). 
SNFAS-HAS-CC7 Beyond Category 2 Design requirements ensure reliable means to stop and maintain stability such that no 
Category 1 or Category 2 event sequence occurs. 
Preventive Design 
8. Misdirection of the horizontal transfer cask transfer trailer/tractor 
off of the edge of the aging pad resulting in a tip-over and damage 
to aging cask (AP). 
SNFAS-HAS-CC8 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC4. Preventive Design 
9. Collision of the aging pad maintenance/surveillance vehicle with 
an aging cask or module staged on aging pad during 
maintenance/ surveillance activity on aging pad causing direct 
damage to an aging cask, or tip-over event (AP). 
SNFAS-HAS-CC9 Beyond Category 2 Operational requirements limit aging pad maintenance/surveillance vehicle maximum 
speed and motive force to limit potential damage caused by collisions involving such 
vehicles from initiating an event sequence. 
Preventive Procedural 
Safety 
10.Collision of the cask tractor with aging cask transporter to be 
towed that causes the horizontal transfer cask tractor to collide 
with aging cask during attachment procedure causing resulting in 
direct damage or tip-over event that damages dual-purpose 
canister (AP and SF). 
SNFAS-HAS-CC10 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC4 Preventive Design 
11.Drop of horizontal transfer cask ram access cover plate during 
removal or installation from a mobile crane onto the horizontal 
transfer cask (without impact limiters) causing damage (AP). 
SNFAS-HAS-CC11 Beyond Category 2 Design requirements ensure that a horizontal transfer cask can withstand a drop of heavy 
objects handled during transfer operations, such as an access cover plate, from the 
maximum handling height without adverse effects. 
Preventive Design
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-162 April 2005 
Table III-37. Disposition of Internal Events That Occur in the SNF Aging System: Horizontal Aging Systems (Continued) 
Disposition of a Potential Event 
Generic Hazard Type Potential Event (Room or Area) 
Potential Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
12.Drop of the horizontal aging module shield door from a mobile 
crane during removal or installation onto the horizontal transfer 
cask (without impact limiters), horizontal aging module, or directly 
onto dual-purpose canister during ram transfer operations causing 
damage (AP). 
SNFAS-HAS-CC12 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC11. Preventive Design 
13. Misalignment or interference of a cask/canister during horizontal 
transfer operation causes dual-purpose canister to jam prior to full 
insertion into a horizontal aging module. Hydraulic ram exerts 
excessive force on misaligned/jammed dual-purpose canister 
causing damage to the dual-purpose canister (AP). 
SNFAS-HAS-CC13 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC14. Additionally, operational 
requirements ensure pre-transfer inspections of empty modules and transfer cask/dualpurpose 
canister interface to prevent interference caused by damaged structures, systems, 
and components or foreign material. 
Preventive Design- 
Procedural 
Safety 
14.Excessive force exerted on the dual-purpose canister by the 
hydraulic ram following full insertion of dual-purpose canister 
resulting in damage to the dual-purpose canister (AP). 
SNFAS-HAS-CC14 Beyond Category 2 Design requirements ensure hydraulic ram can not fail or be operated in a manner that can 
cause dual-purpose canister breach through excess force or ram over-travel. 
Design requirements ensure horizontal dual-purpose canister has sufficient structural 
design margin to withstand maximum ram force events. 
Preventive Design 
15.Damage to dual-purpose canister following a seismic event due to 
incorrect component(s) and/or material used or improper 
installation (e.g., not installed) of seismic restraint (AP). 
SNFAS-HAS-CC15 Beyond Category 2 Operational requirements provide administrative controls on aging system hardware 
configuration management. Operational requirements ensure training of aging system 
workers on specific tasks and checking of work performed to minimize potential for 
installation errors. 
Preventive Procedural 
Safety 
Chemical Contamination- 
Flooding 
1. Chemical spill following collision of the cask tractor with a staged 
cask system, a structure, system, or component, or site vehicle 
causing an acid spill (i.e., batteries). Acid or other chloride 
containing chemical contact with aging system surface results in 
damage to the aging system (e.g., stainless steel stress corrosion 
cracking). Collisions with other vehicles (security vehicles, etc.) or 
a structure, system, or component could also initiate the same 
event sequence (AP, RW, and SF). 
SNFAS-HAS-CCF1 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC4. Additionally, operational 
requirements restrict staging or operation of vehicles along the transfer route or on aging 
pad during transfer operations. Operational requirements develop and implement spill 
prevention and cleanup procedures. 
Preventive Design- 
Procedural 
Safety 
2. Chemical spill following collision an aging pad 
maintenance/surveillance vehicle with a cask system, a structure, 
system, or component, or a site vehicle causing an acid spill (i.e., 
batteries). Acid or other liquid chemical contact with aging system 
surface results in damage to the aging system (e.g., stainless 
steel stress corrosion cracking) (AP). 
SNFAS-HAS-CCF2 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC9. Additionally, operational 
requirements implement spill prevention and cleanup procedures. 
Operational requirements limit the presence of combustible and flammable materials 
stored near or used by the SNF aging system structures, systems, and components, 
including those along the transfer route. 
Preventive Procedural 
Safety 
Explosion-Implosion 1. Explosion-fire following collision of the horizontal transfer cask 
transfer trailer/tractor and/or cask tractor with a staged cask 
system, a structure, system, or component, or a site vehicle 
causing a volatile fuel or hydraulic fluid spill, or hydrogen release 
(i.e., batteries). Collisions with other vehicles (security vehicles, 
etc.) or structure, system, or component could also initiate the 
same event sequence (AP, RW, and SF). 
SNFAS-HAS-EI1 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-CC4. Additionally, design requirements 
ensure capability of withstanding limited hydrogen explosions or fires involving batteries or 
limited quantities of fuel without loss of cask function. Operational requirements limit the 
presence of combustible and flammable materials stored near or used by the SNF aging 
system structures, systems, and components, including those along the transfer route. 
Preventive Design- 
Procedural 
Safety 
2. Explosion and/or fire following collision of an aging pad 
maintenance/surveillance vehicle with aging cask or module 
causing a volatile fuel or hydraulic fluid spill, or hydrogen release 
(i.e., batteries) (AP). 
SNFAS-HAS-EI2 Beyond Category 2 Operational requirements limit aging pad maintenance/surveillance vehicle maximum 
speed and motive force to limit potential damage caused by collisions involving such 
vehicles from initiating an event sequence. Design requirements ensure casks are capable 
of withstanding limited hydrogen explosions or fires involving batteries or limited quantities 
of fuel without loss of cask function. Operational requirements limit the presence of 
combustible and flammable materials stored near or used by the SNF aging system 
structures, systems, and components, including those along the transfer route. 
Preventive Design- 
Procedural 
Safety
Categorization of Event Sequences for License Application 
000-00C-MGR0-00800-000-00B III-163 April 2005 
Table III-37. Disposition of Internal Events That Occur in the SNF Aging System: Horizontal Aging Systems (Continued) 
Disposition of a Potential Event 
Generic Hazard Type Potential Event (Room or Area) 
Potential Event 
Sequence Designator 
Event Sequence 
Category Design, Procedural Safety or Operational Requirement 
Preventive 
or Mitigative 
Requirement 
Design or 
Procedural 
Safety Control 
3. Explosion and/or fire due to welding or cutting activity for cask 
system specific operation (i.e., seismic restraint, vent bird screen, 
radiation shield, or security feature installation-removal) or 
maintenance activity requiring welding/cutting ignites volatile fuel 
or combustibles in the area (AP). 
SNFAS-HAS-EI3 Beyond Category 2 Operational requirements ensure walk-downs are conducted and the potentially explosive 
materials are removed from the area prior to initiating welding activities and require safety 
training as part of welder qualification program. 
Preventive Procedural 
Safety 
4. Explosion and/or fire due to gas cylinder drop, crush, or tip over 
during cask system specific operation (i.e., seismic restraint, vent 
bird screen, radiation shield, or security feature installationremoval) 
or maintenance activity requiring welding/cutting (AP). 
SNFAS-HAS-EI4 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-EI3. Additionally, operational 
requirements ensure welding gas cylinders are properly secured and protected from 
damage when located near SNF aging system structures, systems, and components 
containing SNF or HLW. 
Preventive Procedural 
Safety 
5. Explosion and/or fire due to release and ignition of hydraulic ram 
hydraulic fluid is ignited that damages the aging system (AP). 
SNFAS-HAS-EI5 Beyond Category 2 Same disposition as Potential Event SNFAS-HAS-FT1. Preventive Procedural 
Safety 
Fire-Thermal 1. Transient combustible fire from flammable liquids or combustible 
materials staged on or near the aging pad ignited by unspecified 
ignition source and burn (AP, RW, and SF). 
SNFAS-HAS-FT1 Beyond Category 2 Operational requirements limit the presence of combustible and flammable materials 
stored near or used by the SNF Aging System SSCs, including along the transfer route. 
This ensures that the intensity, duration and magnitude of any fire will not be significant 
enough to initiate a damaged aging cask event sequence. 
Preventive Procedural 
Safety 
2. Malfunction of vent temperature monitoring system results in loss 
of indication or inaccurate monitoring data being observed and 
interpreted by surveillance personnel. Inaccurate monitoring data 
results in a misloaded aging system not being detected and 
damage to contained SNF clad or HLW packaging barriers (AP). 
SNFAS-HAS-FT2 Beyond Category 2 Operational surveillance requirements for monitoring inlet and outlet vent temperature alert 
operators to monitoring system anomaly and initiate corrective actions. 
Preventive Procedural 
Safety 
4. Incorrect installation or defective vent temperature monitoring 
system component(s) results in inaccurate monitoring data being 
observed and interpreted by surveillance personnel. Inaccurate 
monitoring data results in a misloaded aging system not being 
detected and damage to contained SNF clad or HLW packaging 
barriers (AP). 
SNFAS-HAS-FT3 Beyond Category 2 Operational requirements provide administrative controls on aging system hardware 
configuration management and require training of aging system workers on specific tasks 
and checking of work performed to minimize potential for installation errors. Operational 
surveillance requirements for monitoring inlet and outlet vent temperature alert operators to 
monitoring system anomaly and initiate corrective actions. Operational requirements 
include start-up testing and calibration of newly installed instrumentation required to 
monitor thermal heat transfer performance of aging casks. 
Preventive Procedural 
Safety 
Radiation 1. Release of radioactive contamination present inside horizontal 
transfer cask following removal of horizontal transfer cask ram 
closure plate or top closure lid (AP). 
SNFAS-HAS-R1 Beyond Category 2 Operational requirements provide for sampling horizontal transfer cask/dual-purpose 
canister inter-space for contamination at the Transportation Cask Receipt/Return Facility 
prior to transfer to the SNF aging system. 
Preventive Procedural 
Safety 
2. Failure of primary confinement boundary seal welds for welded 
closure cask systems caused by mechanical loads on system 
(from thermal stress, cask drop, or some other hazard) (AP). 
SNFAS-HAS-R2 Beyond Category 2 Design requirements ensure welded closure casks/canister confinement system design 
precludes loss of confinement during life cycle operations and events following closure. 
Operational requirements minimize the potential for mechanical damage to the SNF aging 
system structure, system, or component cask closure systems. 
Preventive Design- 
Procedural 
Safety 
Fissile 1. Criticality associated with a collision or drop of a horizontal 
transfer cask and a rearrangement of the cask internals (AP, RW, 
and SF). 
SNFAS-HAS-F1 Beyond Category 2 Design requirements and waste acceptance criteria ensure criticality safety in 
transportation casks, transfer casks, site-specific casks, and dual-purpose canisters even 
with most reactive credible configuration of fissile material and with optimal moderation. 
Preventive Design 
NOTES: AP = aging pad 17A to 17J; CC = collision-crushing; CCF = chemical contamination flooding; EI = explosion-implosion; F = fissile; FT = fire-thermal; HAS = horizontal cask aging system; R = radiation; RW = roadway to and from aging pads; SF = surface facilities delivering 
or receiving aging casks; SNF = spent nuclear fuel; SNFAS = spent nuclear fuel aging system. 
The Event Sequence Designator is a unique event sequence index for each event in this table. The prefix identifies the building or facility, for example SNFAS, the middle identifies an activity, room, or area, for example HAS, and the suffix identifies the hazard category 
and event number, for example CC1. 
Source: Cogema 2004 [DIRS 171793]