Features, Events, and Processes: Disruptive Events REV 02, ICN 00

ANL-WIS-MD-000005 

November 2004 


1. PURPOSE 
The purpose of this analysis report is to evaluate and document the inclusion or exclusion of the 
disruptive events features, events, and processes (FEPs) with respect to modeling used to support 
the total system performance assessment for license application (TSPA-LA). A screening 
decision, either Included or Excluded, is given for each FEP, along with the technical basis 
for screening decisions. This information is required by the U.S. Nuclear Regulatory 
Commission (NRC) at 10 CFR 63.114 (d), (e), and (f) [DIRS 156605]. 
The FEPs addressed in this report deal with both seismic and igneous disruptive events, such as 
fault displacements through the repository and an igneous intrusion into the repository. For 
included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how 
the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion 
from TSPA-LA (i.e., why the FEP is excluded). Previous versions of this report were developed 
to support the total system performance assessments (TSPA) for various prior repository designs. 
This revision addresses the repository design for the license application (LA). 
1.1 PLANNING 
Documentation requirements for this analysis report are described in the technical work plan 
(TWP) titled Development of Seismic Design Inputs, Preparation of Seismic Topical Reports, 
and Evaluation of Disruptive Events Features, Events, and Processes (BSC 2004 
[DIRS 169886]). The only deviations from the work plan are that 10 CFR 63.114 (c) 
[DIRS 156605] (consideration of alternative conceptual models) and YMRP (NRC 2003 
[DIRS 163274]) acceptance criteria 2.2.1.2.2.3 (3) and (4) (probability model support and 
parameters) were found to be not applicable to this document. Consideration of alternative 
conceptual models and probability model support and parameters are appropriately described in 
the supporting models and other inputs to this report. Any changes in the assigned disruptive 
events FEP list for TSPA-LA that result in proposed additions or deletions to the FEP list are 
further described in Section 6.1.1. 
1.2 SCOPE 
The scope of this report is to describe, evaluate, and document screening decisions and technical 
bases for the disruptive events FEPs for TSPA-LA. For FEPs that are included in the TSPA-LA, 
this analysis report provides a TSPA-LA disposition, which is a consolidated summary of how 
the FEP has been included and addressed in the TSPA-LA model, based on the various 
supporting technical analysis reports and model reports that describe the inclusion of the FEP. 
This report also provides references to the specific supporting technical analysis reports that 
provide more detailed discussions of the included FEPs. For FEPs that are excluded from the 
TSPA-LA, this analysis report provides a screening argument that identifies the basis for the 
screening decision (i.e., low probability, low consequence, or by regulation) and discusses the 
technical basis that supports that decision. This report also provides appropriate references to 
project and non-project information that supports the exclusion. 

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In cases where a FEP covers multiple technical areas and is shared with other FEP reports, this 
analysis report provides only a partial technical basis for the screening decision as it relates to 
disruptive events concerns. The full technical basis for these shared FEPs is addressed, 
collectively, by all of the sharing FEP analysis reports. This information is provided in 
Section 6.2 and subsequent sections and subsections. 
An overview of the Yucca Mountain Project (YMP) FEP analysis and scenario development 
process is available in The Development of the Total System Performance Assessment License 
Application Features, Events, and Processes (BSC 2004 [DIRS 168706]), which describes the 
TSPA-LA FEP identification and screening process. As part of that process, the TSPA-LA FEP 
list (DTN: MO0407SEPFEPLA.000 [DIRS 170760]) was developed. This DTN was used as an 
initial input to the disruptive events FEP analysis. The list of disruptive events TSPA-LA FEPs, 
presented in Table 1-1, was derived from DTN: MO0407SEPFEPLA.000 [DIRS 170760] with 
subsequent modifications to the FEP list, FEP names, and/or FEP descriptions. These 
modifications are documented in the FEP History File in the FEP database (BSC 2004 
[DIRS 168706], Table 6-2) and will be incorporated into a subsequent revision of the TSPA-LA 
FEP List (see Section 7). Table 1-1 also includes the designation of shared FEPs. 
Direct inputs supporting the screening decisions are listed in Section 4. Indirect inputs 
supporting the screening decisions are provided in Section 6.1. The individual FEP discussions 
providing identification (FEP number, name, and description) and screening (screening decision, 
screening argument or TSPA disposition) information are in Section 6.2. 
1.3 SCIENTIFIC ANALYSIS LIMITATIONS AND USE 
The intended use of this analysis report is to provide FEP screening information for a 
project-specific FEP database, and to promote traceability and transparency for both included 
and excluded disruptive events FEPs. This analysis report is intended for use as the 
documentation for inclusion or exclusion of disruptive events FEPs within or from the TSPA-LA 
model. The following limitations apply to this analysis report: 
 Because this analysis report cites other reports and controlled documents as direct input, 
the limitations of this analysis report inherently include any limitations or constraints 
described in the cited reports or controlled documents. 
 In cases where FEPs are shared, the scope of this analysis report is limited to the 
disruptive events aspect of the FEP. The full technical basis for these shared FEPs is 
addressed, collectively, by all of the sharing FEP analysis reports. 
 For screening purposes, this analysis report generally uses mean values of probabilities, 
mean amplitude of events, or mean value of consequences (e.g., mean time to waste 
package degradation) as a basis for reaching an include/exclude decision. Mean values 
are determined based on the range of possible values. 

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 The results of the FEP screening presented in this report are specific to the repository 
design and processes for the YMP available at the time of the TSPA-LA. Changes in 
direct inputs listed in Section 4.1, in baseline conditions used for this evaluation or in 
other subsurface conditions, will need to be evaluated to determine whether the changes 
are within the limits stated in the FEP evaluations. Engineering and design changes are 
subject to evaluation to determine whether there are any adverse impacts to safety, as 
codified at 10 CFR 63.73 and in Subparts F and G [DIRS 156605] (see also the 
requirements at 10 CFR 63.44). 
Table 1-1. Disruptive Events FEPs for TSPA-LA 
FEP Number FEP Name 
Addressed in 
Section 
Sharing FEP 
Analysis Model 
Report 
Seismic - Related FEPs: 
1.2.01.01.0A Tectonic activity-large scale 6.2.1.1 (None) 
1.2.02.03.0A Fault displacement damages EBS components 6.2.1.2 (EBS) 
1.2.03.02.0A Seismic ground motion damages EBS components 6.2.1.3 (EBS) 
1.2.03.02.0B Seismic-induced rockfall damages EBS components 6.2.1.4 (EBS) 
1.2.03.02.0C Seismic-induced drift collapse damages EBS 
components 
6.2.1.5 (EBS) 
1.2.03.02.0D Seismic-induced drift collapse alters in-drift 
thermohydrology 
6.2.1.6 (EBS) 
1.2.03.03.0A Seismicity associated with igneous activity 6.2.1.7 (None) 
1.2.10.01.0A Hydrologic response to seismic activity 6.2.1.8 (UZ, SZ) 
2.2.06.01.0A Seismic activity changes porosity and permeability 
of rock 
6.2.1.9 (UZ, SZ) 
2.2.06.02.0A Seismic activity changes porosity and permeability 
of faults 
6.2.1.10 (UZ, SZ) 
2.2.06.02.0B Seismic activity changes porosity and permeability of 
fractures 
6.2.1.11 (UZ, SZ) 
2.2.06.03.0A Seismic activity alters perched water zones 6.2.1.12 (UZ) 
Igneous-Related FEPs: 
1.2.04.02.0A Igneous activity changes rock properties 6.2.2.1 (UZ, SZ) 
1.2.04.03.0A Igneous intrusion into repository 6.2.2.2 (None) 
1.2.04.04.0A Igneous intrusion interacts with EBS components 6.2.2.3 (None) 
1.2.04.04.0B* Chemical effects of magma and magmatic volatiles 6.2.2.4 (None) 
1.2.04.05.0A Magma or pyroclastic base surge transports waste 6.2.2.5 (None) 
1.2.04.06.0A Eruptive conduit to surface intersects repository 6.2.2.6 (None) 
1.2.04.07.0A Ashfall 6.2.2.7 (BIO) 
1.2.04.07.0C Ash redistribution via soil and sediment transport 6.2.2.8 (None) 
1.2.10.02.0A Hydrologic response to igneous activity 6.2.2.9 (UZ, SZ) 
NOTE: FEPs = features, events, and processes; BIO = Biosphere; SZ = Saturated Zone; 
UZ = Unsaturated Zone; EBS = Engineered Barrier System. 
* New FEP described in this report. 

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2. QUALITY ASSURANCE 
Development of this analysis report and the supporting analyses are subject to the Office of 
Civilian Radioactive Waste Management quality assurance program as identified in the 
Development of Seismic Design Inputs, Preparation of Seismic Topical Reports, and Evaluation 
of Disruptive Events Features, Events, and Processes (BSC 2004 [DIRS 169886], Section 8.1). 
This report contributes to the analysis and modeling used to support performance assessment. 
The disruptive events FEPs documented in this report involve the investigations of items or 
barriers on the Q-List (BSC 2004 [DIRS 168361]), and have the potential to affect the 
calculation of the performance of the natural barriers and various engineered barrier system 
(EBS) components included on the Q-List. However, the disruptive events FEPs themselves do 
not qualify as Q-List items. The evaluations and conclusions do not directly impact engineered 
features important to safety, as defined in AP-2.22Q, Classification Analyses and Maintenance 
of the Q-List. 
Approved QA procedures identified in the TWP (BSC 2004 [DIRS 169886], Section 4.1) have 
been used to conduct and document the activities described in this analysis report, and the 
documentation has been prepared according to AP-SIII.9Q, Scientific Analyses, and in 
accordance with related procedures and guidance documents as outlined in the TWP. The TWP 
also identifies applicable controls for the electronic management of data (BSC 2004 
[DIRS 169886], Section 8.1) during the analysis and documentation activities. 

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3. USE OF SOFTWARE 
This analysis report uses no computational software; therefore, this analysis is not subject to 
software controls. The analyses and arguments presented in this report are based on guidance 
and regulatory requirements, on results of analyses presented and documented in other analysis 
reports, or on other technical literature. Software and models used in the supporting documents 
are cited in this analysis report for traceability and transparency purposes, but were not used in 
its development. 
This analysis report was developed using only commercial, off-the-shelf software. Microsoft 
Word 2000, used for word processing, is exempt from qualification requirements in accordance 
with LP-SI.11Q, Software Management. 

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4. INPUTS 
AP-3.15Q, Managing Technical Product Inputs categorizes technical product input usage as 
either direct or indirect input. Direct input is used to develop the results or conclusions in a 
technical product. Indirect input is used to provide additional information that is not used in the 
development of results or conclusions. Direct inputs are addressed in this Section. Indirect 
inputs are addressed in Section 6.1.3. 
Section 4.1 identifies all direct inputs used in this FEP analysis report. The direct inputs were 
obtained from controlled source documents and other appropriate sources in accordance with 
AP-3.15Q, Managing Technical Product Inputs. Section 4.2 identifies the FEP screening criteria 
described in 10 CFR Part 63 [DIRS 156605], along with the regulatory-derived FEP screening 
criteria. Section 4.3 identifies applicable codes and standards. 
4.1 DIRECT INPUTS 
The LA FEP List (DTN: MO0407SEPFEPLA.000 [DIRS 170760]) was used as a direct input to 
provide the initial list of disruptive events FEPs for screening in this analysis report. The LA 
FEP List identifies a FEP or a set of sharing FEP analysis reports for each FEP. Subsequent 
additions to or changes from that FEP list (numbers, names, or descriptions) are reflected in the 
information provided in Section 6.2 and can be traced through the FEP History File in the FEP 
database (BSC 2004 [DIRS 168706], Table 6-2). Appendix A lists direct inputs used for the FEP 
screening analysis for both included and excluded FEPs. Non-project direct inputs have been 
qualified for intended use in Appendix C and in a data qualification report prepared per 
AP-S.III.2Q, as described in Section 6.1.4. 
The regulations at 10 CFR Part 63 [DIRS 156605] also provide direct inputs to the FEP 
screening process. By specifying characteristics, concepts, and definitions, the regulations serve 
as de facto inputs used for screening FEPs. For additional information on regulatory definitions, 
and an elucidation of the regulatory concepts pertaining to the reference biosphere, geologic 
setting, reasonably maximally exposed individual (RMEI), and human intrusion, the reader is 
referred to The Development of the Total System Performance Assessment-License Application 
Features, Events, and Processes (BSC 2004 [DIRS 168706], Section 4.1.3), which is an indirect 
input to this document. For the disruptive events FEPs, the inputs of particular interest include 
the relationship of the geologic setting to the reference biosphere, and the location of the 
reasonably maximally exposed individual (RMEI). Specific direct inputs from the regulations 
addressing these concepts are listed in Table 4-1. 

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Table 4-1. Direct Input from Regulations Used for the Disruptive Events FEP Screening 
Source 
Input 
Category Direct Use In Description 
10 CFR 63.2 Established 
Fact 
6.2.2.9 Regulatory definition for reference biosphere 
10 CFR 63.302 Established 
Fact 
6.2.2.2 
6.2.2.3 
6.2.2.5 
6.2.2.6 
6.2.2.7 
6.2.2.8 
Regulatory definitions for accessible 
environment and controlled area 
10 CFR 63.312 Established 
Fact 
6.2.2.2 
6.2.2.3 
6.2.2.5 
6.2.2.6 
6.2.2.7 
6.2.2.8 
Regulatory characteristics of the RMEI 
Source: 10 CFR Part 63 [DIRS 156605]. 
DOE = U.S. Department of Energy. 
The definitions and concepts discussed in The Development of the Total System Performance 
Assessment-License Application Features, Events, and Processes (BSC 2004 [DIRS 168706], 
Section 4.1.3.3) indicate that the RMEI is located no closer than 18 km to the south in the 
direction of groundwater flow and above the highest concentration of radionuclides in the plume 
of contamination (in accordance with 10 CFR 63.312 (a), (b), (c), (d), and (e) [DIRS 156605]), 
and that the limit of the controlled area is no greater than 5 km from the repository in any other 
direction (as specified at 10 CFR 63.302 [DIRS 156605]). The location of the RMEI and the 
associated distance from the repository are of primary interest in evaluating potential exposure 
risk due to potential releases at the repository. The location of the RMEI is also important for 
determining exposure and is part of the technical basis for included FEPs. The location and 
characteristics of the RMEI for the nominal scenario class are also used for the disruptive 
scenario classes. 
The reference biosphere must be consistent with present knowledge of conditions in the region, 
and changes in the biosphere (other than climate) from conditions at the time of license 
application submittal should not be projected (BSC 2004 [DIRS 168706], Section 4.1.3.2; 
10 CFR 63.305(a), (b) [DIRS 156605]). The geologic setting (geology, hydrology, and climate) 
may evolve based upon cautious but reasonable assumptions, consistent with present knowledge 
of factors that could affect the system in the next 10,000 years (BSC 2004 [DIRS 168706], 
Section 4.1.3.2). 
By NRCs juxtaposition of the geologic and hydrologic factors within the subsection addressing 
required characteristics of the reference biosphere, it is inferred that the listed regulatory 
constraint of changes in the reference biosphere may also be applicable to conditions that may 

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occur at Yucca Mountain. This approach agrees with the statement at 10 CFR 63.102(i) 
[DIRS 156605] that: 
Characteristics of the reference biosphere and the reasonably maximally exposed 
individual are to be based on current human behavior and biospheric conditions in 
the region, as described in 63.305 and 63.312 [DIRS 156605]. 
4.2 CRITERIA 
This section addresses the criteria relevant to the FEP screening process. These criteria stem 
from the applicable regulations at 10 CFR Part 63 [DIRS 156605], as identified in the Project 
Requirements Document (PRD) (Canori and Leitner 2003 [DIRS 166275]). These criteria find 
expression as specific acceptance criteria presented by the NRC in the Yucca Mountain Review 
Plan, Final Report (YMRP) (NRC 2003 [DIRS 163274], Sections 2.2.1.2.1.3 and 2.2.1.2.2.3). 
The correlation of the regulations and YMRP acceptance criteria are shown in Table 4-2. These 
criteria are also listed in section 3 of the TWP (BSC 2004 [DIRS 169886]). Readers should note 
that since this analysis report summarizes and reports the results of supporting analysis reports 
and other information, discussions of representativeness of results are not appropriate here, and 
are not included. 
4.2.1 Projects Requirements Document 
The PRD (Canori and Leitner 2003 [DIRS 166275]) documents and categorizes the regulatory 
requirements and other project requirements and provides a cross-reference to the various YMP 
organizations that are responsible for ensuring that the criteria have been addressed in the license 
application. The regulatory requirements include criteria relevant to performance assessment 
activities, in general, and to FEP-related activities as they pertain to performance assessment, in 
particular. Table 4-2 provides a crosswalk between the regulatory requirements, the PRD, and 
the acceptance criteria provided in the YMRP (NUREG-1804, NRC 2003 [DIRS 163274], 
Sections 2.2.1.2.1.3 and 2.2.1.2.2.3). 
Table 4-2. Relationships of Regulations to the YMRP Acceptance Criteria 
10 CFR Part 63 
[DIRS 156605] 
Canori and Leitner 2003 
[DIRS 166275] 
Description of the 
Applicable Regulatory 
Requirement or 
Acceptance Criterion Regulatory Citation 
Associated 
PRD 
Associated 
Criteria 
in the YMRP 
[DIRS 163274] 
General Requirements and Scope Pertinent to FEP Screening 
Include data related to 
geology, hydrology, and 
geochemistry (including 
disruptive processes and 
events). 
63.114(a) 
PRD-002/ 
T-015 
2.2.1.2.1.3 
Acceptance 
Criterion 1 
Include information on the 
design of the engineered 
barrier system used to 
define parameters and 
conceptual models. 
63.114(a) 
PRD-002/ 
T-015 
2.2.1.2.1.3 
Acceptance 
Criterion 1 

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Table 4-2. Relationships of Regulations to the YMRP Acceptance Criteria (Continued) 
10 CFR Part 63 
[DIRS 156605] 
Canori and Leitner 2003 
[DIRS 166275] 
Description of the 
Applicable Regulatory 
Requirement or 
Acceptance Criterion Regulatory Citation 
Associated 
PRD 
Associated 
Criteria 
in the YMRP 
[DIRS 163274] 
General Requirements and Scope Pertinent to FEP Screening 
Account for uncertainties 
and variabilities in 
parameter values and 
provide the technical basis 
for parameter ranges, 
probability distributions, or 
bounding values. 
63.114(b) 
PRD-002/ 
T-015 
2.2.1.2.2.3 
Acceptance 
Criteria 
2 and 5 
FEP Screening Criteria 
Provide the justification 
and technical basis for 
excluding FEPs 
specifically excluded by 
regulation. 
Not Applicable Not Applicable 
2.2.1.2.1.3 
Acceptance 
Criterion 2 
Provide the technical basis 
for either inclusion or 
exclusion of FEPs. 
Provide the justification 
and technical basis for 
those excluded based on 
probability. 
63.114(d) 
63.342 
PRD-002/ 
T-015 
PRD-002/ 
T-034 
2.2.1.2.1.3 
Acceptance 
Criterion 2 
2.2.1.2.2.3 
Acceptance 
Criteria 
1 and 2 
Provide the technical basis 
for either inclusion or 
exclusion of FEPs. 
Provide the justification 
and the technical basis for 
FEPs excluded based on 
lack of significant change 
in resulting radiological 
exposure or release to the 
accessible environment. 
63.114 
(e and f) 
63.342 
PRD-002/ 
T-015 
PRD-002/ 
T-034 
2.2.1.2.1.3 
Acceptance 
Criterion 2 
2.2.1.2.2.3 
Acceptance 
Criteria 
1 and 2 
4.2.2 Yucca Mountain Review Plan 
The NRC will be reviewing the license application. The basis of the review is described in the 
YMRP (NRC 2003 [DIRS 163274], Section 2.2.1.2), and the bases for acceptance are stated as 
acceptance criteria. In Table 4-2, YMRP acceptance criteria are correlated to the corresponding 
regulations as they pertain to FEP-related criteria. 
The cited YMRP (NRC 2003 [DIRS 163274]) criteria are provided in Table 4-3. The YMRP 
acceptance criteria for FEP screening echo the regulatory screening criteria of low probability 
and low consequence, but also allow for exclusion of a FEP if the process is specifically 
excluded by the regulations (see Section 4.2.3). 

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Table 4-3. Relevant YMRP Acceptance Criteria 
YMRP Section 
Acceptance 
Criterion Description 
1. The Identification 
of a List of FEPs Is 
Adequate 
The safety analysis report contains a complete list of FEPs related to 
the geologic setting or the degradation, deterioration, or alteration of 
engineered barriers (including those processes that would affect the 
performance of natural barriers) that have the potential to influence 
repository performance. The list is consistent with the site 
characterization data. The comprehensive features, events, and 
processes list includes, but is not limited to, potentially disruptive 
events related to igneous activity (extrusive and intrusive); seismic 
shaking (high-frequency-low magnitude, and rare large-magnitude 
events); tectonic evolution (slip on existing faults and formation of 
new faults); climatic change (change to pluvial conditions); and 
criticality. 
The DOE has identified all FEPs related to either the geologic setting 
or to the degradation, deterioration, or alteration of engineered 
barriers (including those processes that would affect the performance 
of natural barriers) that have been excluded. 
The DOE has provided justification for those FEPs that have been 
excluded. An acceptable justification for excluding FEPs is that either 
the FEP is specifically excluded by regulation; probability of the FEP 
(generally an event) falls below the regulatory criterion; or omission of 
the feature, and process does not significantly change the magnitude 
and time of the resulting radiological exposures to the reasonably 
maximally exposed individual, or radionuclide releases to the 
accessible environment. 
Scenario Analysis 
and Event 
Probability: 
Scenario Analysis 
(from Section 
2.2.1.2.1.3 
NUREG-1804 
[DIRS 163274]) 
2. Screening of the 
Initial List of FEPs Is 
Appropriate 
The DOE has provided an adequate technical basis for each FEP, 
excluded from the performance assessment, to support the 
conclusion that either the FEP is specifically excluded by regulation; 
the probability of the FEP falls below the regulatory criterion; or 
omission of the FEP does not significantly change the magnitude and 
time of the resulting radiological exposures to the reasonably 
maximally exposed individual, or radionuclide releases to the 
accessible environment. 
Events or event classes are defined without ambiguity and used 
consistently in probability models, such that probabilities for each 
event or event class are estimated separately. 
1. Events are 
Adequately Defined 
Probabilities of intrusive and extrusive igneous events are calculated 
separately. Definitions of faulting and earthquakes are derived from 
the historical record, paleoseismic studies, or geological analyses. 
Criticality events are calculated separately by location. 
2. Probability 
Estimates for Future 
Events Are Supported 
by Appropriate 
Technical Bases 
Probabilities for future natural events are based on past patterns of 
the natural events in the Yucca Mountain region, considering the 
likely future conditions and interactions of the natural and engineered 
repository system. These probability estimates have specifically 
included igneous events, faulting and seismic events, and criticality 
events. 
Scenario Analysis 
and Event 
Probability: 
Identification of 
Events with 
Probability Greater 
than 10-8 per Year 
(from Section 
2.2.1.2.2.3 
NUREG-1804 
[DIRS 163274]) 
5. Uncertainty in 
Event Probability is 
Adequately Evaluated 
Probability values appropriately reflect uncertainties. Specifically: 
a. The DOE provides a technical basis for probability values used, 
and the values account for the uncertainty in the probability 
estimates. 
b. The uncertainty for reported probability values adequately reflects 
the influence of parameter uncertainty on the range of model results 
(i.e., precision) and the model uncertainty, as it affects the timing and 
magnitude of past events (i.e., accuracy). 

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4.2.3 FEPs Screening Criteria 
The criteria for determining low probability, low consequence, or regulation exclusions are 
described below. 
Low Probability 
The low-probability criterion is stated in 10 CFR 63.114(d) [DIRS 156605]: 
Consider only events that have at least one chance in 10,000 of occurring over 
10,000 years. 
And low-probability criterion is supported by 10 CFR 63.342 [DIRS 156605]: 
The U.S. Department of Energys (DOE) performance assessments shall not 
include consideration of very unlikely features, events, or processes, i.e., those 
that are estimated to have less than one chance in 10,000 of occurring within 
10,000 years of disposal. The DOE assessments for the human-intrusion and 
groundwater protection standards shall not include consideration of unlikely 
features, events, and processes, or sequences of events and processes, i.e., those 
that are estimated to have less than one chance in 10 and at least one chance in 
10,000 of occurring within 10,000 years of disposal. 
As noted in Assumption 5.1, the low-probability criterion for very unlikely events corresponds to 
an annual-exceedance probability of 10.8. The criterion for unlikely events corresponds to an 
annual-exceedance probability of 10.5 to 10.8. 
Low Consequence 
The low consequence criterion is stated in 10 CFR 63.114 (e) and (f) [DIRS 156605]: 
(e) Provide the technical basis for either inclusion or exclusion of specific features, 
events, and processes in the performance assessment. Specific features, events, 
and processes must be evaluated in detail if the magnitude and time of the 
resulting radiological exposures to the reasonably maximally exposed individual, 
or radionuclide releases to the accessible environment, would be significantly 
changed by their omission. 
(f) Provide the technical basis for either inclusion or exclusion of degradation, 
deterioration, or alteration processes of engineered barriers in the performance 
assessment, including those processes that would adversely affect the 
performance of natural barriers. Degradation, deterioration, or alteration 
processes of engineered barriers must be evaluated in detail if the magnitude and 
time of the resulting radiological exposures to the reasonably maximally exposed 
individual, or radionuclide releases to the accessible environment, would be 
significantly changed by their omission. 

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And low consequence criterion is supported by 10 CFR 63.342 [DIRS 156605]: 
DOE performance assessments need not evaluate the impacts resulting from any 
features, events, and processes or sequences of events and processes with a higher 
chance of occurrence if the results of the performance assessments would not be 
changed significantly. 
Some FEPs have a beneficial effect on the TSPA, as opposed to an adverse effect. As identified 
in 10 CFR 63.102(j) [DIRS 156605], the concept of a performance assessment includes that: 
The features, events, and processes considered in the performance assessment 
should represent a wide range of both beneficial and potentially adverse effects on 
performance (e.g., beneficial effects of radionuclide sorption; potentially adverse 
effects of fracture flow or a criticality event). Those features, events, and 
processes expected to materially affect compliance with 10 CFR 63.113(b) or be 
potentially adverse to performance are included, while events (event classes or 
scenario classes) that are very unlikely (less than one chance in 10,000 over 
10,000 years) can be excluded from the analysis.  
The Yucca Mountain Review Plan, Final Report (NRC 2003 [DIRS 163274], Section 2.2.1), 
states that: 
In many regulatory applications, a conservative approach can be used to decrease 
the need to collect additional information or to justify a simplified modeling 
approach. Conservative estimates for the dose to the reasonably maximally 
exposed individual may be used to demonstrate that the proposed repository 
meets U.S. Nuclear Regulatory Commission regulations and provides adequate 
protection of public health and safety. The total system performance assessment 
is a complex analysis with many parameters, and the U.S. Department of Energy 
may use conservative assumptions to simplify its approaches and data collection 
needs. However, a technical basis that supports the selection of models and 
parameter ranges or distributions must be provided. 
On the basis of these statements, those FEPs that are demonstrated to have only beneficial effects 
on the radiological exposures to the reasonably maximally exposed individual or radionuclide 
releases to the accessible environment can be excluded on the basis of low consequence because 
they have no adverse effects on performance. 
By Regulation 
The Yucca Mountain Review Plan, Final Report (NRC 2003 [DIRS 163274], Section 2.2.1.2.1.3, 
Acceptance Criterion 2) allows for exclusion of a FEP if the process is specifically excluded by 
the regulations. The report states: 
The DOE has provided justification for those FEPs that have been excluded. An 
acceptable justification for excluding FEPs is that either the FEP is specifically 
excluded by regulation; probability of the FEP (generally an event) falls below the 
regulatory criterion; or omission of the feature and process does not significantly 

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change the magnitude and time of the resulting radiological exposures to the 
reasonably maximally exposed individual, or radionuclide releases to the 
accessible environment. 
4.3 CODES, STANDARDS, AND REGULATIONS 
No standards, regulations, or code requirements other than those cited in Sections 4.1 and 4.2 
apply to this document. 

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5. ASSUMPTIONS 
This section addresses assumptions used in the FEP screening for the disruptive events FEPs. 
Assumption 5.1: For naturally occurring FEPs, it is assumed that regulations expressed as a 
probability criterion can also be expressed as an annual-exceedance probability, which is 
defined as the probability that a specified value (such as for ground motions or fault 
displacement) will be exceeded during one year. More specifically, a stated 
probability-screening criterion of one chance in 10,000 in 10,000 years (10-4/104 yr) is assumed 
equivalent to a 10-8 annual-exceedance probability. Likewise, the probability criterion of one 
chance in 10 in 10,000 years (10-1/104 yr), as used in assessments of human intrusion and 
groundwater protection standards, is assumed equivalent to a 10-5 annual-exceedance probability. 
JustificationThe definition of annual exceedance probability and the following justification for 
this assumption is taken from Characterize Framework for Seismicity and Structural 
Deformation at Yucca Mountain, Nevada (BSC 2004 [DIRS 168030], Glossary). 
The assumption of equivalence of annual-exceedance probability is appropriate. This 
assumption satisfies the definition of a Poisson distribution as a mathematical model of the 
number of outcomes obtained in a suitable interval of time and space, that has its mean equal to 
its variance1 This definition is inferred to mean that naturally occurring, infrequent, and 
independent events can be represented as stochastic processes in which distinct events occur in 
such a way that the number of events occurring in a given period of time depends only on the 
length of the time period. The use of this assumption is justified in Characterize Framework for 
Seismicity and Structural Deformation at Yucca Mountain, Nevada (BSC 2004 [DIRS 168030], 
Section 6.4.2), which indicates that the underlying assumption in all probabilistic hazard 
analyses is that the behavior of the earth is generally Poissonian or random. 
Although there may be cases where sufficient data and information exist to depart from this 
assumption, the Poissonian model is generally an effective representation of nature and it 
represents a compromise between the complexity of natural processes, availability of 
information, and the sensitivity of results of engineering relevance. Consequently, for geologic 
processes that occur over long time spans, assuming annual equivalence over a 10,000-year 
period (a relatively short time span for geologic-related events) is reasonable and consistent with 
the basis of probabilistic hazard analyses. Therefore, no further confirmation is required. 
UseThis assumption is used throughout Section 6.2 of this report, either implicitly or explicitly, 
for each of the disruptive events FEPs that cite to an annualized probability or 
annual-exceedance frequency. 
Assumption 5.2: It is assumed that potential naturally occurring events, but perhaps of different 
magnitude, have occurred at least once in the past within the geologic record. This assumption is 
the basis for determining the factors that could affect the Yucca Mountain disposal system over 
the next 10,000 years. 
1 Merriam-Websters Collegiate Dictionary, 10th ed., s.v. Poisson distribution. 

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JustificationThis assumption is justified because it is consistent with the regulations used as 
direct input. At 10 CFR 63.305(c) [DIRS 156605], DOE is directed to vary factors related to the 
geology, hydrology, and climate based upon cautious, but reasonable assumptions consistent with 
present knowledge of factors that could affect the Yucca Mountain disposal system over the next 
10,000 years. 
The implication of this assumption is that any discernible impacts or processes related to past 
events on the site setting are reflected in the present knowledge of natural processes that form the 
basis of the TSPA. If the subject FEP phenomena are not reflected or discernible in the data 
used to describe past settings, then they are either of low consequence or of low probability and 
can be excluded from consideration. Because it is consistent with the regulations, no further 
confirmation is necessary. 
UseThis assumption is used throughout. It is particularly germane to FEPs related to processes 
or phenomena that, speculatively, could affect future states of the system, but for which the 
magnitude and/or coupling to the effect on the repository is not well defined, or for which 
consequences in present time are known to be minor. 
These types of events are known to occur. However, the effects of the phenomenon or the 
effects associated with varying magnitudes of the event type and probabilities are not well 
documented (e.g., effects of a supernova); the form of the coupling process is not well defined 
(e.g., changes in the earth's magnetic field), or the phenomenon has been shown to have no 
impact or insignificant impact at the present time (e.g., earth tides). 
Assumption 5.3It is assumed that the repository will be constructed, operated, and closed 
according to the regulatory requirements applicable to the construction operation and closure 
period. Deviations from design will be detected and corrected. 
Justification: Inherent in the FEPs evaluation approach is the assumption that the repository 
will be constructed, operated, and closed according to the design used as the basis for the FEP 
screening and in accordance with NRC license requirements. This assumption is inherent in 
performance evaluation of any engineering project, and design verification and performance 
confirmation are required as part of the construction and operation processes. Therefore, no 
further confirmation of the assumption is required. 
Engineering and design changes are subject to evaluation to determine if there are any adverse 
impacts to safety as codified at 10 CFR 63.73 and in Subparts F and G [DIRS 156605]. See also 
the requirements at 10 CFR 63.32, 10 CFR 63.44, and 10 CFR 63.131 [DIRS 156605]. 
These requirements call for periodic updates and special reports regarding: 
 Progress of construction 
 Any data about the site obtained during construction and not within the predicted limits 
on which the facility design was based 

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 Any deficiencies in design and construction that could adversely affect safety at any 
future time if uncorrected 
 Results of research and development programs being conducted to resolve safety 
questions. 
Use: Any changes in direct inputs listed in Section 4.1, in baseline conditions used for this 
evaluation, or in other subsurface conditions will need to be evaluated to determine if the 
changes are within the limits stated in the FEP evaluations. This assumption is used in all FEPs 
that depend on the size of the repository footprint, orientation of the drifts, or other design 
features such as backfilled connecting drifts, for example 1.2.02.03.0A (Fault displacement 
damages EBS components) and 1.2.04.04.0A (Igneous intrusion interacts with EBS 
components).

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6. ANALYSES 
The following sections discuss the disruptive events FEP analyses. Section 6.1 of this analysis 
report discusses the methods and approach used for the FEP screening. Section 6.2 provides the 
screening documentation. 
6.1 METHODS AND APPROACH 
The identification and screening of a comprehensive list of FEPs potentially relevant to the 
postclosure performance of the Yucca Mountain repository is an ongoing, iterative process based 
on site-specific information, design, and regulations. FEP analysis uses the following 
definitions, as taken from the Yucca Mountain Review Plan, Final Report (NRC 2003 
[DIRS 163274], Glossary): 
feature An object, structure, or condition that has a potential to affect disposal system 
performance. 
event A natural or human-caused phenomenon that has a potential to affect disposal 
system performance and that occurs during an interval that is short compared to 
the period of performance. 
process A natural or human-caused phenomenon that has a potential to affect disposal 
system performance and that operates during all or a significant part of the period 
of performance. 
FEP analysis for TSPA-LA is described in The Development of the Total System Performance 
Assessment-License Application Features, Events, and Processes (BSC 2004 [DIRS 168706]). It 
is also summarized in the following subsections. 
6.1.1 FEP Identification 
The first step of FEP analysis is FEP identification and classification, which addresses 
Acceptance Criterion 1 of the Yucca Mountain Review Plan, Final Report (NRC 2003 
[DIRS 163274], Section 2.2.1.2.1.3). The TSPA-LA FEP identification and classification 
process is described in The Development of the Total System Performance Assessment-License 
Application Features, Events, and Processes (BSC 2004 [DIRS 168706], Section 3). This 
process produced a version of the LA FEP List (DTN: MO0407SEPFEPLA.000 
[DIRS 170760]), which is used as initial input in this disruptive events FEP analysis. 
Subsequent modifications to the FEP list from the information shown in 
DTN: MO0407SEPFEPLA.000 [DIRS 170760], aside from editorial corrections to FEP 
descriptions, are discussed later in this section. All subsequent modifications are also 
documented in the FEP History File in the FEP database (BSC 2004 [DIRS 168706], Table 6-2). 
As part of the TSPA-LA FEP identification process, a new FEP to evaluate the chemical effects 
of magma and magmatic volatiles is described in this report for the igneous scenario. The new 
FEP (1.2.04.04.0B) titled Chemical effects of magma and magmatic volatiles, is evaluated in 
Section 6.2.2.4 of this report. Consequently, this analysis report addresses 21 FEPs that are 
identified as disruptive events FEPs for TSPA-LA. 

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6.1.2 Feature, Event, and Process Screening Process 
The second step of FEP analysis is FEP screening, which addresses Acceptance Criterion 2 of 
the Yucca Mountain Review Plan, Final Report (NRC 2003 [DIRS 163274], Section 2.2.1.2.1.3). 
The TSPA-LA FEP screening process is described in The Development of the Total System 
Performance Assessment-License Application Features, Events, and Processes (BSC 2004 
[DIRS 168706], Section 4). 
For FEP screening, each FEP is screened against the specified exclusion criteria (see 
Section 4.2.3) summarized in the three following FEP screening statements: 
 FEPs having less than one chance in 10,000 of occurring over 10,000 years may be 
excluded (screened out) from the TSPA on the basis of low probability (as per 
10 CFR 63.114(d) and 63.342 [DIRS 156605]). 
 FEPs, whose omission would not significantly change the magnitude and time of the 
resulting radiological exposures to the RMEI, or radionuclide releases to the accessible 
environment, may be excluded (screened out) from the TSPA on the basis of low 
consequence (as per 10 CFR 63.114 (e) and (f) [DIRS 156605]). 
 FEPs that are inconsistent with the characteristics, concepts, and definitions specified in 
10 CFR Part 63 [DIRS 156605] may be excluded (screened out) from the TSPA by 
regulation. 
A FEP need only satisfy one of the exclusion screening criteria to be excluded from TSPA. 
A FEP that does not satisfy any of the exclusion screening criteria must be included (screened in) 
in the TSPA-LA model. 
This analysis report documents the screening decisions for the disruptive events FEPs. In cases 
where a FEP covers multiple technical areas and is shared with other FEP analysis reports, this 
analysis report provides only a partial technical basis for the screening decision as it relates to 
disruptive events issues. The full technical basis for these shared FEPs is addressed, collectively, 
by all of the sharing FEP analysis reports. 
For postclosure evaluation of fault-displacement (Section 6.2.1.2; FEP 1.2.02.03.0A) and seismic 
FEPs requiring ground motion inputs (e.g., Section 6.2.1.3; 1.2.03.02.0A), the FEP screening 
statements are applied based on the mean value of the event at an annual-exceedance probability 
of 10-8 (BSC 2004 [DIRS 169183], Table 4-1 and Table 6.1-1). For the total system 
performance assessment for site recommendation, the DOE elected to use median hazard curves 
to screen seismic FEPs, considering the median curve representative of the hazards central 
tendency at an annual-exceedance frequency lower than approximately 10-6. However, NRC 
reviewers suggested that using the median hazard for FEP screening is inconsistent with 
established NRC practice for use of probabilistic seismic hazard analyses (PSHA) in risk 
assessment. Consequently, the DOE has implemented an alternative approach for TSPA-LA that 
uses the mean values. The decision to use this alternative approach is documented in Williams 
(2001 [DIRS 161728]). 

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The use of the mean value from the hazard curve is particularly pertinent to the following FEPs: 
1.2.02.03.0A Fault displacement damages EBS components (Section 6.2.1.2) 
1.2.03.02.0A Seismic ground motion damages EBS components (Section 6.2.1.3) 
1.2.03.02.0B Seismic-induced rockfall damages EBS components (Section 6.2.1.4) 
1.2.03.02.0C Seismic-induced drift collapse damages EBS components (Section 6.2.1.5) 
1.2.03.02.0D Seismic-induced drift collapse alters in-drift thermohydrology 
(Section 6.2.1.6). 
Documentation of the screening for each FEP is provided in Section 6.2. The following 
standardized format is used: 
Section 6.2.X.X FEP Name (FEP Number) 
FEP Description: This field describes the nature and scope of the FEP under consideration. 
Screening DecisionIdentifies the screening decision using one of the following descriptions: 
 Included 
 ExcludedLow Probability 
 ExcludedLow Consequence 
 ExcludedBy Regulation 
In a few cases, a FEP may be excluded by a combination of two criteria (e.g., low probability 
and low consequence). 
Screening ArgumentThis field is used only for excluded FEPs. It provides the discussion for 
why a FEP has been excluded from TSPA-LA. 
TSPA DispositionThis field is used only for included FEPs. It provides the consolidated 
discussion of how a FEP has been included in TSPA-LA, making reference to more detailed 
documentation in other supporting technical analysis reports, as applicable. 
Supporting ReportsThis field is only used for included FEPs. It provides the list of supporting 
technical analysis reports that identified the FEP as an included FEP and contain information 
relevant to the implementation of the FEP within the TSPA-LA model. This list of supporting 
technical analysis reports provides traceability of the FEP through the document hierarchy. For 
excluded FEPs it is indicated as Not Applicable. 
6.1.3 Supporting Analysis Reports and Indirect Inputs 
Table 6-1 lists the supporting reports, defined in Section 6.1.2, that have been cited for all 
included igneous and seismic FEPs. The data sources, product outputs, and references used for 
the FEP evaluations are also cited within each of the individual FEP discussions. The direct 
inputs for each FEP are documented in Section 4, per YMP procedural requirements and 
guidance. 

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Table 6-1. Supporting Reports for Included FEPs 
DIRS Number Supporting Report 
169183 Seismic Consequence Abstraction 
168030 Characterize Framework for Seismicity and Structural Deformation at Yucca Mountain, Nevada 
170027 Development of Earthquake Ground Motion Input for Preclosure Seismic Design and 
Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, Nevada 
169753 Mechanical Assessment of the Drip Shield Subject to Vibratory Motion and Dynamic and Static 
Rock Loading 
170063 Mechanical Assessment of the Waste Package Subject to Vibratory Ground Motion 
166107 Drift Degradation Analysis 
169565 Multiscale Thermohydrologic Model 
169131 Abstraction of Drift Seepage 
169980 Characterize Eruptive Processes at Yucca Mountain, Nevada 
169989 Characterize Framework for Igneous Activity at Yucca Mountain, Nevada 
170028 Dike/Drift Interactions 
170001 Number of Waste Packages Hit by Igneous Intrusion 
170026 Atmospheric Dispersal and Deposition of Tephra from a Potential Volcanic Eruption at Yucca 
Mountain, Nevada 
Other project and external source documents are cited as needed in individual FEPs to amplify 
the discussions, but are corroborative or referential in nature. Appendix B provides the list of 
supporting document sources that are cited as indirect sources to seismic and igneous related 
FEPs. 
6.1.4 Qualification of Unqualified Direct Inputs 
Direct Inputs are listed in Appendix A and any unqualified data are identified by footnotes to the 
direct inputs table or otherwise identified as being qualified by procedure. These inputs are 
qualified for use in a separate report Qualification of Igneous Inputs to Disruptive Events 
Features, Events, and Processes (BSC 2004 [DIRS 171999]), qualified per AP-SIII.2Q, 
Qualification of Unqualified Data. The data are from Crowe et al. 1986 ([DIRS 101532]), which 
is used as direct input in Section 6.2.2.5, FEP 1.2.04.05.0A (Magma or pyroclastic base surge 
transports waste). Some of the data summarized in Crowe et al. 1986 ([DIRS 101532]) were 
collected under the Nevada Nuclear Waste Storage Investigation project in the early 1980s. 
These data were not subject to a quality assurance program that was compliant with 10 CFR 60, 
Subpart G. The qualification status of Crowe et al. 1986 ([DIRS 101532]) is indicated in the 
DIRS database and Appendix A, Table A-1. Appendix C documents justification of additional 
unqualified data obtained from an outside source for intended use per the requirements of 
AP-SIII.9Q. 

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6.1.5 Assumptions and Simplifications 
For included FEPs, the TSPA-LA dispositions may include statements regarding assumptions 
made to implement the FEP within the TSPA-LA model. Such statements are descriptive of the 
manner in which the FEP has been included and are not used as the basis of the screening 
decision to include the FEP with the TSPA-LA model. 
Because the individual FEPs are specific in nature, any discussion of applicable mathematical 
formulations, equations, algorithms, numerical methods, or idealizations or simplifications are 
provided within the individual FEP discussions in Section 6.2. 
6.1.6 Intended Use and Limitations 
The intended use of this analysis report is to provide FEP screening information for a 
Project-specific FEP database and to promote traceability and transparency regarding FEP 
screening. This analysis report is intended to be used as the documentation for the FEP database 
described in The Development of the Total System Performance Assessment-License Application 
Features, Events, and Processes (BSC 2004 [DIRS 168706]). For included FEPs, this document 
summarizes and consolidates the method of implementation of the FEP in TSPA-LA in the form 
of TSPA-LA disposition statements, based on more detailed implementation information in the 
listed supporting technical analysis reports. For excluded FEPs, this document provides the 
technical basis for exclusion in the form of screening arguments. 
Inherent in this evaluation approach is the limitation that the repository will be constructed, 
operated, and closed according to the design used as the basis for the FEP screening and in 
accordance with NRC license requirements. This limitation is inherent in performance 
evaluation of any engineering project, and design verification and performance confirmation are 
required as part of the construction and operation processes. The results of the FEP screening 
presented in this report are specific to the repository design evaluated in this analysis report for 
TSPA-LA. 
Any changes in direct inputs listed in Section 4.1, in baseline conditions used for this evaluation, 
or in other subsurface conditions will need to be evaluated to determine if the changes are within 
the limits stated in the FEP evaluations. Engineering and design changes are subject to 
evaluation to determine if there are any adverse impacts to safety as codified at 10 CFR 63.73 
and in 10 CFR 63 Subparts F and G [DIRS 156605]. See also the requirements at 10 CFR 63.44 
and 10 CFR 63.131 ([DIRS 156605]). 
As discussed in sections 1.3, 4.2, and 7, this report summarizes the results of supporting analysis 
reports and other information. There is no testing or modeling associated with the development 
of this report, no new information is developed or presented, and no calculations or analyses are 
preformed within this document. Therefore, consistent with Section 2.3 of the TWP (BSC 2004 
[DIRS 169886]), the procedural requirements of AP-SIII.9Q, Attachment 2, Section 6, 
concerning items such as uncertainties, alternate scientific approaches, and alternate 
software/computational methods are not applicable to this document. They have been addressed 
in the input documents. 

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6.2 DISRUPTIVE EVENTS FEATURE, EVENT, AND PROCESS SCREENING AND 
ANALYSIS 
This report addresses the 21 disruptive events FEPs that are identified for TSPA-LA 
consideration. Section 6.2.1 addresses the FEPs classified and assigned as seismic-related FEPs, 
and Section 6.2.2 addresses the FEPs classified and assigned as igneous-related FEPs. For all 
FEPs that have been evaluated as included, the discussion of the FEP will provide a brief 
summary of the basis for inclusion and a description of the manner by which the included FEP is 
incorporated in the TSPA-LA. For all FEPs that have been evaluated as excluded, the discussion 
of the FEP will provide the basis for exclusion. In those cases where a FEP is shared with 
another discipline, a cross-reference will be made to the appropriate FEP subsystem where all the 
discussions for each FEP will be collected. These subsystems include the engineered barrier 
system (EBS), unsaturated zone (UZ), and saturated zone (SZ). 
6.2.1 Seismic-Related FEPs 
The following subsections provide the screening decision and related discussions for the 
seismic-related FEPs: 
1.2.01.01.0A Tectonic activity-large scale (Section 6.2.1.1) 
1.2.02.03.0A Fault displacement damages EBS components (Section 6.2.1.2) 
1.2.03.02.0A Seismic ground motion damages EBS components (Section 6.2.1.3) 
1.2.03.02.0B Seismic-induced rockfall damages EBS components (Section 6.2.1.4) 
1.2.03.02.0C Seismic-induced drift collapse damages EBS components (Section 6.2.1.5) 
1.2.03.02.0D Seismic-induced drift collapse alters in-drift thermohydrology 
(Section 6.2.1.6) 
1.2.03.03.0A Seismicity associated with igneous activity (Section 6.2.1.7) 
1.2.10.01.0A Hydrologic response to seismic activity (Section 6.2.1.8) 
2.2.06.01.0A Seismic activity changes porosity and permeability of rock (Section 6.2.1.9) 
2.2.06.02.0A Seismic activity changes porosity and permeability of faults (Section 6.2.1.10) 
2.2.06.02.0B Seismic activity changes porosity and permeability of fractures 
(Section 6.2.1.11) 
2.2.06.03.0A Seismic activity alters perched water zones (Section 6.2.1.12). 

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6.2.1.1 Tectonic Activity-Large Scale (1.2.01.01.0A) 
FEP Description: Large-scale tectonic activity, such as regional uplift, subsidence, 
folding, mountain building, or other processes related to plate 
movements, could affect repository performance by altering the 
physical and thermohydrologic properties of the geosphere. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: Global or plate-scale tectonics drives tectonism at the regional 
scale, and regional scale features, such as the Walker Lane, are 
expressed at the site scale as faults, folds, and similar features. Site 
scale features, events and processes related to tectonic activity, 
such as volcanism, faulting, seismicity, and fracturing, are 
evaluated as separate FEPs. 
Large-scale tectonic activity is interpreted for this FEP to refer to tectonism that is expressed at a 
regional scale (1:250,000 to 1:500,000 or even less) and that has the potential to produce broad 
uplift, subsidence, folding, faulting, and geothermal effects. These changes, if they were to 
occur at a sufficient rate, could potentially impact UZ and SZ flow and transport properties 
during the repository performance period (10,000 years), thereby affecting dose and radionuclide 
release to the accessible environment. The basis for exclusion of large-scale tectonic activity is 
two-fold. First, rates of tectonic activity in the vicinity of Yucca Mountain are low, and if they 
were to occur uniformly across the region, no impacts are anticipated. For example, if all of the 
Southern Great Basin is gradually and uniformly uplifted a few meters over the next 
10,000 years, there is no conceivable affect on radionuclide release from the repository. Second, 
it is explicitly recognized that large-scale tectonic activity can manifest itself locally, such as by 
displacement on a fault near the repository. These types of site-scale FEPs are treated as 
separate FEPs to ensure that their potential impacts are adequately evaluated. This two-fold 
approach ensures that all aspects of the large-scale tectonic activity FEP are appropriately 
addressed. 
In the paragraphs that follow, documentation is provided for the low rate of tectonic activity in 
the vicinity of Yucca Mountain and several scenarios are discussed that support the screening 
decision for Exclusion of this FEP. In addition, cross-references are made to discussions of 
related FEPs, where appropriate. 
Low Rates of Tectonic ActivityYucca Mountain lies within the Southern Great Basin of the 
Basin and Range tectonic province and is located on the south flank of a large Miocene caldera 
complex. Structurally, the mountain is dominated by subparallel fault blocks that trend to the 
north and dip to the east. The blocks of ash-flow tuff are bounded by typical Basin and Range 
style, high-angle, generally west-dipping, normal and oblique faults that formed by rapid 
east-west extension during the waning phases of Miocene volcanism (BSC 2004 [DIRS 169989], 
Sections 6.1.1.1 and 6.4.1.1). The Miocene is defined as 23.8 Ma to 5.3 Ma. Secondary 
intrablock faults are common. Yucca Mountain is also within the Walker Lane, a 100-km-wide 
structural belt along the western edge of the Basin and Range province. The Walker Lane is 
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faults that accommodated much of the early extension in this region. At a more local scale, 
Yucca Mountain is within the Crater Flat Domain, and is located just east of the Crater Flat 
basin. The peak phase of tectonism took place during the middle Miocene, and the region has 
since experienced declining strain rates. 
During the period of peak tectonism (approximately 11.6 to 12.7 Ma), the western part of Crater 
Flat basin subsided due to the basin extending from 18 to 40 percent in 1.1 million years or less. 
After 11.6 Ma, the rate of extension in the basin declined in a roughly exponential manner. The 
late Quaternary rate of extension is less than 1 percent of the initial rate (Fridrich et al. 1998 
[DIRS 164051], pp. 1 and 13) and may be as low as 0.1 to 0.2 percent per million years (Fridrich 
et al. 1998 [DIRS 164051], pp. 19 and 20). The pattern of Quaternary deformation mimics the 
pattern of middle Miocene activity; however (as just discussed), at substantially lower rates 
(Fridrich et al. 1998 [DIRS 164051], pp. 1 and 2). Even during the Quaternary, the rate of 
subsidence appears to have diminished consistently over the last several million years and the 
locus of subsidence due to the waning extension has migrated west of Yucca Mountain (inferred 
from Fridrich 1999 [DIRS 118942], p. 189; Dixon et al. 1995 [DIRS 102793], p. 765). Although 
Crater Flat basin remains technically active, it is now in an advanced state of decline according 
to Fridrich et al. (1998 [DIRS 164051], p. 2). 
As described in Characterize Framework for Seismicity and Structural Deformation at Yucca 
Mountain, Nevada (BSC 2004 [DIRS 168030], Section 6.3.1), tectonically, the Basin and Range 
is currently experiencing extensional strain at a low to moderate rate with low to moderate 
historical seismicity. Support for this statement comes from several sources. Fridrich (1999 
[DIRS 118942], p. 190) indicates that across the southern part of the Crater Flat Basin, the 
northwest-southeast lengthening is approximately 0.1 m per thousand years. He also states that 
the late Quaternary extension rate is approximately one-half as great across central Yucca 
Mountain, and an order of magnitude lower across northern Yucca Mountain. Savage et al. 
(1999 [DIRS 118952]) present an evaluation of the rate of strain accumulation at Yucca 
Mountain, Nevada, for the period from 1983 to 1998. They also address alternative 
interpretations indicating higher strain-accumulation rates presented by Wernicke et al. (1998 
[DIRS 103485]). The contemporary strain-accumulation rate in the Yucca Mountain area is very 
slow (less than 2 mm/yr) (Savage et al. 1999 [DIRS 118952], p. 17627). Reported as principal 
strain accumulation rate of 2 +/ 12 nanostrain/year at N87W +/ 12 and 22 +/ 12 
nanostrain/year at N03E +/ 12, this strain accumulation is consistent with the paleoseismic 
slip rates calculated from Quaternary fault-displacement studies. Fault slip rates considered most 
probable at Yucca Mountain range from 0.0010.03 mm/yr, excluding the Stagecoach fault, 
which may locally measure 0.05 mm/yr (BSC 2004 [DIRS 168030], Table 6). The slip rate 
range represents the Solitario Canyon and Bow Ridge faults, which, as discussed in 
Section 6.2.1.2 (FEP 1.2.02.03.0A), are considered the block-bounding faults with the most 
potential to affect the repository. 
Since uncertainties in strain rates are reflected at the site scale in uncertainties in recurrence and 
slip rates, uncertainty in the tectonic strain rate is implicitly evaluated through the consideration 
of multiple tectonic models and through uncertainties in the recurrence rates (CRWMS M&O 
1998 [DIRS 103731], Sections 7.1.1, 8.1.3, and Appendix E). The resulting hazard curves are 
used to evaluate FEPs specific to those issues. 

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ANL-WIS-MD-000005 REV 02 6-9 November 2004 
The present extensional-tectonic regime of the Yucca Mountain region does not promote 
significant tectonic uplift and mountain building. Based on the history of the Crater Flat Basin 
as presented in Characterize Framework for Seismicity and Structural Deformation at Yucca 
Mountain, Nevada (BSC 2004 [DIRS 168030]), and described briefly above, tectonic subsidence 
due to regional extension is a more likely scenario at Yucca Mountain than uplift. Subsidence 
will not perceptibly be advanced in the absence of significant slip along the block-bounding 
faults. Probable fault slip rates for block-bounding faults at Yucca Mountain (i.e., Solitario 
Canyon and Bow Ridge faults) are low, measuring at most 0.03 mm/yr (BSC 2004 
[DIRS 168030], Table 6). The probability of such movement is reflected in the hazard curves 
presented in the PSHA (CRWMS M&O 1998 [DIRS 103731]) and used in the specific FEP 
evaluations for ground motion and faulting, which have been included. Thus, there is no 
mechanism not already considered (i.e., seismic ground motion and fault displacement) 
stemming from an extensional terrain that would lead to increased exposure or increased release 
of radionuclides to the accessible environment. 
Physical Separation from Tectonically Active AreasTectonic activity at a regional scale 
typically is concentrated in zones or belts of ten, to hundreds of kilometers in width (Thatcher 
et al. 1999 [DIRS 119053], pp. 1714 to 1715) and persists for millions of years. The closest 
significant tectonic zones relevant to a discussion of Yucca Mountain include the eastern 
California shear zone, located west of the Funeral Mountains (west of Yucca Mountain), and the 
intermountain seismic belt, located generally north of 37N latitude (north of Yucca Mountain) 
(Savage et al. 1995 [DIRS 104553], p. 20263). These zones and belts are characterized by 
relatively high geodetic strain rates and recurrent earthquakes (Thatcher et al. 1999 
[DIRS 119053], pp. 1714 and 1715). In contrast, Yucca Mountain and its setting (i.e., the Crater 
Flat domain) have a lower geodetic strain rate (Savage et al. 1999 [DIRS 118952], p. 17627). 
The low geodetic strain rate (Savage et al. 1995 [DIRS 104553], p. 20263 and Figure 9), and low 
seismicity levels (e.g., Rogers et al. 1987 [DIRS 100176], p. 82) found in the Crater Flat domain 
suggest that the site area is located in a tectonic domain that may be isolated from the zones of 
high geodetic strain located to the west and to the north. 
Possible Impacts on Infiltration RatesLarge-scale tectonic activity is reflected at the site as 
regional scale features such as faults and folds, as well as topography. Changes to such features 
resulting from large-scale tectonic activity may have an affect on infiltration. Day et al. (1996 
[DIRS 124302], p. 2-7) observes deformation features in the hanging wall block associated with 
the Bow Ridge fault that suggest beds in the hanging wall block have been tilted and fractured 
associated with fault displacement. Future deformation in the hanging wall block will be low, 
not exceeding the strain associated with even the highest local fault slip rate (e.g., 0.05 mm/yr for 
the Stage Coach Road fault, which would amount to 0.5 m in 10,000 years). Therefore, 
deformation within the hanging wall block is not expected to be significant. It follows that any 
impact on infiltration due to future hanging wall deformation is considered negligible. 
Furthermore, the PSHA suggests the majority of future strain will be accommodated on 
block-bounding faults (see FEP 2.2.06.02.0B). This is corroborated by a critical tilting angle of 
approximately 25 (Fridrich et al. 1996 [DIRS 105086], pp. 2-21 and 2-22). Block faulting will 
occur before an increase in fold-limb dip (and associated fracturing in the hangwall block) 
becomes a significant factor in determining local percolation. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-10 November 2004 
The effects of fractures on percolation flux have also been evaluated in a sensitivity study 
(BSC 2004 [DIRS 170012], Appendix D). Minor changes in fractured rock will not significantly 
affect infiltration or groundwater flow because increased fracturing will not occur to a degree 
greater than, or no more significant than, other uncertainties related to infiltration (BSC 2004 
[DIRS 170012], Appendix D). That analysis also concluded that changes in fracture aperture 
confined to fault zones show virtually no effect on transport behavior. Furthermore, increased 
fracture aperture applied over the entire UZ domain results in effects that are no more significant 
than other uncertainties related to infiltration (BSC 2004 [DIRS 170012], Appendix D). 
Changes in porosity and permeability of faults, fractures, and the rock matrix are further 
addressed as specific FEPs. 
The low rates of tectonic activity discussed previously related to uplift and subsidence; also 
apply to changes in topography. Given low and declining rates of tectonic activity, topographic 
changes will also not impact infiltration rates. 
Possible Impacts on the Geothermal RegimeWith regard to the geothermal regime, Yucca 
Mountain is now located in an area of moderate heat flow in the Southern Great Basin and lies 
south of the regions of higher crustal heat flow in the northern part of the Great Basin 
(Lachenbruch and Sass 1978 [DIRS 142990], pp. 212 and 246). The advent of basaltic 
volcanism at about 11 Ma, as described by Crowe et al. (1995 [DIRS 100110], pp. 4-1 and 4-2), 
signaled the end of crustal-level magmatism near Yucca Mountain. The description indicates 
generation of small, discrete batches of basaltic magma at upper-mantle depths (45 to 60 km 
(28 to 36 mi)) that are capable of making their way quickly to the surface (Crowe et al. 1995 
[DIRS 100110], pp. 5-2 and 5-6). Only small volumes (less than 0.5 km3) of basaltic magma 
have been generated in the Yucca Mountain region during the Quaternary (Crowe et al. 1995 
[DIRS 100110], p. 5-5). 
For the existing geothermal gradient to change significantly, there would have to be a major 
change in the present tectonic setting (see Low Rates of Tectonic Activity above). For example, a 
large volume of magma emplaced high in the mid-to-upper crust at approximately 5 km in depth 
(inferred from Lachenbruch and Sass 1978 [DIRS 142990], pp. 224 and 244) could bring the 
Yucca Mountain area to a pre-eruptive state with attendant hot-spring activity. However, this 
example would require great extension rates and crustal mobility, a rapidly evolving mantle, and 
subcrustal conditions that involve either a mantle plume hot spot (Parsons et al. 1994 
[DIRS 106479], p. 83), or melting of a weakened subducting slab (inferred from Bohannon and 
Parsons 1995 [DIRS 101865], p. 957). A significant (i.e., potentially hazardous) increase in 
geothermal gradient associated with tectonic activity would probably require several million 
years of evolution of the tectonic setting. 
The present tectonic state of Yucca Mountain and the present source of basaltic-magma 
generation at depths around 45 to 60 km (Crowe et al. 1995 [DIRS 100110], p. 5-2 and 
Figure 5-1) are consistent with the present geothermal gradient. By way of corroboration, after a 
two-year study, scientists at the University of Nevada Las Vegas (UNLV) concluded that 
hydrothermal water has not invaded the rocks of Yucca Mountain in at least two million years 
(Wilson and Cline 2001 [DIRS 155426]). The study indicates that fluid inclusions within 
minerals found in roughly half of the 155 rock samples collected throughout Yucca Mountain for 
the study were formed at temperatures ranging from 113F to 141F (45C to 60C). Moreover, 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-11 November 2004 
calcite deposited in fractures and voids was not the result of deposition from the upwelling of 
geothermal water. The uranium-lead dating for the study indicates that the two-phase fluid 
inclusions are older than a minimum age of 1.9 million years. More precise age constraints on 
the two-phase fluid inclusions (based on associated dateable material) indicated that the 
two-phase fluid inclusions were older than 4.0 to 5.3 million years. The UNLV study concluded 
that mineral precipitation at the site has been stable for at least the last two to three million years 
and is consistent with formation from low temperature surficial fluids, rather than saturation of 
the site by upwelling hydrothermal fluids. 
The existing geothermal regime is currently addressed, and conditions sufficient to create or 
allow a significant change in the regional geothermal regime within the 10,000-year performance 
period are absent. Consequently, there is no feasible and additional geothermal regime-related 
mechanism considered capable of leading to an increased exposure or an increased release of 
radionuclides into the accessible environment. This aspect of the FEP, therefore, is excluded 
based on low consequence. 
Possible Impacts on Rates of VolcanismA tectonic-related increase in volcanism could 
potentially impact the performance of the repository. Details of igneous events as they relate to a 
proposed repository at Yucca Mountain are specifically addressed in Characterize Framework 
for Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989]). Furthermore, the 
Probabilistic Volcanic Hazard Assessment (PVHA) (CRWMS M&O 1996 [DIRS 100116]) 
documents the results of an expert elicitation project that provided the technical basis for 
assessing hazards related to volcanism. The use of tectonic models as they relate to volcanic 
hazard is summarized in the PVHA (CRWMS M&O 1996 [DIRS 100116]). The PVHA serves 
as the basis for estimates of future igneous intrusion probability. The PVHA method 
incorporated the possibility that volcanic events are clustered in time. The PVHA also 
incorporated the possible waning or waxing of volcanic activity in the region during the period 
of time the experts believed was relevant to hazard analysis (BSC 2004 [DIRS 169989], 
Section 6.3.1.3). Thus, there is no igneous-related mechanism that has not already been 
considered (i.e., increased igneous activity related to tectonic changes) that would lead to an 
increased exposure or an increased release of radionuclides into the accessible environment. 
Possible Impacts on Water LevelThe evaluation of this FEP included consideration of the 
change in the spatial relationship of the repository and the current water table due to a 
tectonic-related mechanism. If a significant change (rise) in the water table were to occur, there 
could be potential impacts on repository performance. The mechanisms for such changes to 
occur could involve rising of the water level; lowering of the repository; or a combination of the 
effects of the first two. This consequence is excluded due to the factors described in 
conditions 1, 2, and 3 below. 
(1) Rising of the water level. The vertical distance between the base of the repository and 
the saturated zone is approximately 300 m. Stuckless (1996 [DIRS 119051], pp. 98 
to 99) discusses excursions of the water table in Plio-Pleistocene time, and indicates 
that past water level elevations are estimated to have been a maximum of about 115 m 
higher than present levels. Stuckless further indicates that neither geologic evidence 
for these past elevations nor hydrologic flow models suggest that the rises in the water 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-12 November 2004 
table in response to climate changes, similar to those of the past 2 million years, would 
be sufficient to threaten the repository horizon in the future. 
These past water level elevations reflect the effects of wetter climates and perhaps 
greater strain rates than currently exist. Climate changes have been considered and 
are included in the TSPA-LA models. Changes in strain rates could, hypothetically, 
also cause an increase in water levels. However, the horizontal geodetic 
strain-accumulation rate in the Yucca Mountain region is currently low, at 
approximately less than 2 mm/yr (Savage et al. 1999 [DIRS 118952], p. 17627), with 
the strain reported as a nanostrain/yr rate. A change to a significantly higher rate 
would require major changes to the tectonic regime, which is a process requiring 
millions (not thousands) of years. Furthermore, regional strain patterns indicate 
waning effects of strain extension east of Death Valley (inferred from Fridrich 1999 
[DIRS 118942], p. 191) with relatively minimal changes in strain conditions. A rise 
in water level, or change in head, could also be related to sudden changes in the strain 
conditions due to an earthquake and could result in seismic pumping as reported in 
Gauthier et al. (1996 [DIRS 100447], pp. 163 to 164). This corroborative analysis 
was performed for the total system performance assessment for viability assessment 
(TSPA-VA) to simulate the timing, amplitude, and duration of water-table rise, and 
indicated a maximum and temporary rise of 50 m within an hour of a simulated 
seismic event (Gauthier et al. 1996 [DIRS 100447], p. 164). This mechanism is 
described more fully for FEP 1.2.10.01.0A (Hydrologic response to seismic activity) 
and has been excluded. Therefore, neither regional changes in tectonic strain rates, 
nor seismic events have the potential to raise the water level at Yucca Mountain the 
300 m needed to impact the repository during the 10,000-year performance period. 
(2) Lowering the repository: Under long-term extension, normal faulting has caused the 
faulted blocks of Yucca Mountain to subside into Crater Flat basin. However, the rate 
of subsidence is proportional to the paleoseismic slip rate, amounting to no more than 
0.3 m in 10,000 years or 30 m in a 1 million year period. As stated previously, 
probable fault slip rates for block-bounding faults are no more than 0.03 mm/yr 
(BSC 2004 [DIRS 168030], Table 6). This cumulative displacement is small 
compared to the distance separating the repository and the water table. Therefore, 
cumulative fault offset alone is insufficient to cause the water table to approach the 
repository level given current rates of fault movement at Yucca Mountain. 
(3) Combination of effects: Even if expected subsidence (0.3 m in 10,000 years) occurs, 
the accompanying water table rise would need to be on the order of 300 m for this FEP 
to be of any consequence. Based on geologic evidence as previously discussed, and as 
shown in the discussion regarding water table rise, the maximum increase in the water 
table (associated with climate change) would be no more than 115 m. So, the distance 
between the water level and the repository would decrease by no more than 
approximately 115.3 m. Therefore, the combined effects of a maximum water table 
rise and an expected subsidence of 0.3 m are insufficient to cause the water table to 
reach the repository level. Even if these two mechanisms were coupled with a seismic 
event (resulting in a temporary additional 50-m water table rise for a total of 165.3 m), 
the water table would still remain approximately 134.7 m below the repository level. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-13 November 2004 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.1.2 Fault Displacement Damages EBS Components (1.2.02.03.0A) 
FEP Description: Movement of a fault that intersects drifts within the repository may 
cause the EBS components to experience related movement or 
displacement. Repository performance may be degraded by such 
occurrences as tilting of components, component-to-component 
contact, or drip shield separation. Fault displacement could cause 
a failure as significant as shearing of drip shields and waste 
packages by virtue of the relative offset across the fault, or as 
extreme as exhumation of the waste to the surface. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: Faulting is considered to be a potentially disruptive process with 
effects that include sudden relative rock/soil displacements across 
a fault surface (i.e., fault displacement). These effects are 
potentially relevant to the integrity of the repository and are 
included in the TSPA-LA. The analysis model report supporting 
the Screening Decision contains a table of included FEPs with 
pointers to more detailed background information on this FEP 
(BSC 2004 [DIRS 169183], Table 6.2-1). Ground motions 
associated with fault displacements and rock fall are addressed 
under separate FEPs. 
The following technical basis for inclusion involves a comparison of the potential fault 
displacement occurring at a 10-8 annual frequency (see Assumption 5.1 in Section 5) to various 
elements of the repository design (i.e., waste package-to-drift wall spacing and set-back 
requirements). As discussed in Seismic Consequence Abstraction (BSC 2004 [DIRS 169183], 
Section 6.7.2), the potential for fault displacement damage from block-bounding and intra-block 
faults and features likely to exist within the repository is included in the TSPA-LA. Block 
bounding faults are implicitly included, while other faulting within the repository block are 
explicitly included. Fault displacement could impact waste packages through mechanical 
damage caused directly by the fault displacement (BSC 2004 [DIRS 169183], Section 6.7). 
The history of faulting and the nature of fault slip and its structural effects at Yucca Mountain 
are well known (CRWMS M&O 1998 [DIRS 103731]; Whitney 1996 [DIRS 100188]). In situ 
stress measurements indicate that faults at Yucca Mountain are at the yield state (Stock and 
Healey 1988 [DIRS 101022], p. 92; Stock et al. 1985 [DIRS 101027], p. 8705). The PSHA 
considers these factors and provides the results of the expert-elicitation process as it applies to 
probable fault displacements at Yucca Mountain. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-14 November 2004 
The PSHA (CRWMS M&O 1998 [DIRS 103731], Figures 8-2 to 8-14, p. 8-7) specifically 
examines displacements at specific points along block-bounding faults (Points 1 and 2), and 
intra-block faults (Points 3 through 6 and 9). The PSHA assessed features likely to be found 
within the repository (Points 7 and 8) with various preexisting conditions, including the 
occurrence of features within the intact rock (Points 7d and 8d). These points were chosen to 
represent the range of conditions that may be encountered near or within the repository. 
Table 6-2 provides the median and mean fault displacements for the 10-8 annual-exceedance 
probability. The mean values for fault displacements at annual-exceedance probabilities of less 
than 10-6 are increasingly skewed toward larger displacements relative to median values. 
Therefore, the mean values shown in Table 6-2 represent a conservative projection of potential 
fault displacements and are used for the evaluations discussed below. 
Table 6-2. Annualized Frequency of Exceedance and Displacements for Various Locations within the 
TSPA-LA Repository Footprint 
Location 
Median Displacement (cm) for 
Postclosure 
Mean Displacement (cm) 
for 
Postclosure 
Annual Frequency 
10-8 10-8 
1. Bow Ridge fault 200 600 
2. Solitario Canyon fault 300 >1000 
3. Drill Hole Wash fault 30 240 
4. Ghost Dance fault 59 160 
5. Sundance fault 9.9 ~145 
6. Unnamed fault west of Dune Wash 20 210 
7a. A hypothetical small fault with 2 m of offset, 
located about 100 m east of Solitario 
Canyon fault 
2.1 ~75 
7b. A hypothetical shear with 10 cm of offset, 
located about 100 m east of Solitario 
Canyon fault 
<0.1 9 
7c. A hypothetical fracture, located about 100 m 
east of Solitario Canyon fault (no cumulative 
displacement) 
<0.1 <1 
7d. Intact rock, located about 100 m east of 
Solitario Canyon fault <0.1 <0.1 
8a. A hypothetical small fault with 2 m of offset, 
located between the Solitario Canyon fault 
and the Ghost Dance fault 
2.1 ~75 
8b. A hypothetical shear with 10 cm of offset, 
located between the Solitario Canyon fault 
and the Ghost Dance fault 
<0.1 9 
8c. A hypothetical fracture, located between the 
Solitario Canyon fault and the Ghost Dance 
fault 
<0.1 <1 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-15 November 2004 
Table 6-2. Annualized Frequency of Exceedance and Displacements for Various Locations within the 
TSPA-LA Repository Footprint (Continued) 
Location 
Median Displacement (cm) for 
Postclosure 
Mean Displacement (cm) 
for 
Postclosure 
Annual Frequency 
10-8 10-8 
8d. Intact rock, located between the Solitario 
Canyon fault and the Ghost Dance fault <0.1 <0.1 
9 Midway Valley, fracture with no cumulative 
displacement 28 200 
Source: BSC 2004 [DIRS 169183], Table 6.7-5 and DTN: MO0401MWDRPSHA.000 [DIRS 166962], from files: 
/displ/tot_haz/s1.frac_mean.gz; /displ/tot_haz/s2.frac_mean.gz; ./displ/tot_haz/s3.frac_mean.gz; 
./displ/tot_haz/s4.frac_mean.gz; ./displ/tot_haz/s5.frac_mean.gz; ./displ/tot_haz/s6.frac_mean.gz; 
/displ/tot_haz/s7a.frac_mean.gz; /displ/tot_haz/s7b.frac_mean.gz; ./displ/tot_haz/s7c.frac_mean.gz; 
./displ/tot_haz/s7d.frac_mean.g; ./displ/tot_haz/s8a.frac_mean.gz; ./displ/tot_haz/s8b.frac_mean.gz; 
./displ/tot_haz/s8c.frac_mean.gz; ./displ/tot_haz/s8d.frac_mean.gz; ./displ/tot_haz/s9.frac_mean.gz. 
NOTE: Zero displacement at Sites 7d and 8d at >10-8 annual frequency is documented in 
DTN: MO0401MWDRPSHA.000 [DIRS 166962]. See also Probabilistic Seismic Hazard Analyses for Fault 
Displacement and Vibratory Ground Motion at Yucca Mountain, Nevada (CRWMS M&O 1998 
[DIRS 103731], Section 8.2.1). Some displacement information was scaled from figures presented in the 
PSHA (CRWMS M&O 1998 [DIRS 103731], Figures 8-2 to 8-14 and p. 8-7) and may be approximate. 
Mean values for 10-8 annual frequency were extrapolated from Probabilistic Seismic Hazard Analyses for 
Fault Displacement and Vibratory Ground Motion at Yucca Mountain, Nevada (CRWMS M&O 1998 
[DIRS 103731], Figure 8-3) for Site 2. 
Block-Bounding FaultsThe block-bounding faults include the Bow Ridge fault (Point 1) and the 
Solitario Canyon fault (Point 2). The Bow Ridge fault is located to the east of the waste 
emplacement area, whereas the Solitario Canyon fault parallels the western repository footprint 
boundary. At a 10-8 annual-exceedance probability (see Assumption 5.1), the estimated mean 
displacements are 6 m and greater than 10 m, respectively (Table 6-2). Both of these estimated 
mean displacements are greater than the nominal 5.5-m tunnel diameter planned for the 
emplacement drifts, so any engineered components present at the location of offset and 
displacement would be damaged. The Solitario Canyon fault and the Bow Ridge fault lie outside 
the emplacement area of the repository and require standoffs, as defined in the Underground 
Layout Configuration (BSC 2003 [DIRS 165572], Section 7.1.3). 
Intrablock Faults and other Features Likely to Be Found in the RepositoryThe Drill Hole Wash 
fault, Pagany Wash fault, and Sever Wash fault are northwest-trending parallel intra-block faults 
that intersect the emplacement drifts in the northeast section of the repository (CRWMS M&O 
1998 [DIRS 103731], Figure 4-9). Referring to Table 6-2, the fault displacement hazard for the 
Drill Hole Wash fault is assumed (BSC 2004 [DIRS 169183], Section 5.2) to apply to the Pagany 
Wash fault and Sever Wash fault for purposes of determining consequences of their intersection 
with emplacement drifts. The Sundance fault is also considered in the fault displacement 
consequence model. Fault displacements range from 240 cm (Drill Hole Wash fault) to 
approximately 145 cm (Sundance fault) for the mean annual frequency 10-8 per year (Table 6-2). 
The disposition of the Ghost Dance fault in the TSPA-LA is discussed below. 
Additionally, other displacement features that are likely to be found within the repository are 
represented in the PSHA using a fixed location within the repository, but with hypothetical 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-16 November 2004 
existing characteristics (Points 7 and 8). The PSHA (CRWMS M&O 1998 [DIRS 103731], 
Figures 8-8 to 8-13) addresses such features within the waste-emplacement area by assessing the 
probability of displacement along existing small faults, shears, and fractures, as represented in 
the PSHA for Points 7a, 7b, 7c, 8a, 8b, and 8c as explained in Table 6-2. The mean 10-8 
annual-exceedance probability for these small faults, shears, and fractures is 75 cm, 9 cm, and 
less than 1 cm, respectively. The PSHA (CRWMS M&O 1998 [DIRS 103731], p. 8-7) also 
examines the probability of displacement in the intact rock (Points 7d and 8d) at these 
hypothetical locations. The PSHA indicates that there is only a very unlikely probability (less 
than 10-8 annual-exceedance probability) that movement greater than 0.1 cm will occur in the 
intact rock. The potential for displacement in the intact rock is inferred to be analogous to the 
creation of new faults and fractures. 
The fault displacement analysis considers a range of displacement, ranging from a maximum of 
240 cm at the Drill Hole Wash fault and similarly oriented faults, down to less than 0.1 cm for 
intact rock (BSC 2004 [DIRS 169183], Table 6.7-5). To determine whether this range of 
displacements is significant to repository performance, the displacements are compared to the 
spatial gaps between various EBS components. This determination is dependent on whether the 
faulting occurs within a collapsed drift or an uncollapsed drift, which depends on the lithophysal 
or nonlithophysal character of the repository (BSC 2004 [DIRS 169183], Section 6.7.1 and 
6.7.2.1). 
The analysis concludes that no damage will occur to waste packages without tunnel collapse 
(BSC 2004 [DIRS 169183], Section 6.7.4 and 6.7.2.1). See FEPs 1.2.03.02.0B (Section 6.2.1.4) 
and 1.2.03.02.0C (Section 6.2.1.5) for a detailed discussion of seismic-induced drift degradation 
in lithophysal and nonlithophysal zones. For fault displacement, analyses find that known faults 
intersect emplacement drifts in lithophysal and nonlithophysal zones. For faulting at locations 
other than at known faults, analyses also conclude intersections occur in lithophysal and 
nonlithophysal zones (BSC 2004 [DIRS 169183], Section 6.7.2.2). Intersections are assumed to 
occur only in lithophysal zones because this is most restrictive in terms of clearance for the waste 
package and because the fraction of the overall repository in the lithophysal zone is 0.85, 
compared to 0.15 for nonlithophysal zones (BSC 2004 [DIRS 169183], Sections 6.7.2.1 and 
6.7.2.2). 
Depending on the type of waste package, maximum allowable displacement within a collapsed 
drift (lithophysal zone) ranges from 671 to 1,079 mm (BSC 2004 [DIRS 169183], Section 6.7.1 
and Table 6.7-8). Comparing these values to fault displacement from mean hazard curves 
(Table 6-2) provides the technical basis for the analysis. At the 10-6 annual exceedance 
frequency and less, the analysis concludes all boiling water reactor (BWR), pressurized water 
reactor (PWR), and naval spent nuclear fuel (naval) waste packages will survive a fault 
displacement event for Sites 7a and 8a in collapsed tunnels within lithophysal zones (BSC 2004 
[DIRS 169183], Section 6.7.4). The maximum fault displacement for Sites 7 and 8 is 75 cm 
(750 mm), less than the allowable fault displacement of 852 mm for the naval waste package 
group with drift collapse. Again, the same conclusion is valid for the BWR and PWR waste 
package designs with even greater margin. 
However, at mean annual exceedance frequencies between 10-7 per year and 10-8 per year, waste 
package failure may occur for any of the waste packages placed directly over four considered 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-17 November 2004 
faults: the Drillhole Wash, Pagany, Sever, and Sundance faults. The same condition applies to 
the high-level radioactive waste package group placed over faults characterized by location 7a 
and 8a. In these cases, the fault displacement values in Table 6-2 exceed the maximum 
allowable displacements for the binned waste types PWR, BWR, naval and high-level 
radioactive waste (BSC 2004 [DIRS 169183], Section 6.7.4). The potential for fault 
displacement to impact waste packages through mechanical damage is explicitly included in the 
TSPA-LA, as described below (i.e., Block-bounding faults and Intrablock Faults and other 
Features Likely to Be Found in the Repository). 
Consideration of Exhumation Due to Fault DisplacementThe FEP description also mentions the 
extreme case of fault displacements leading to waste exhumation. The depth of the repository 
below the surface is on the order of 200 m or greater (BSC 2004 [DIRS 164519]; BSC 2003 
[DIRS 165572]). The potential for exhumation due to fault movement is not credible given the 
low fault slip rates on block-bounding faults (i.e., Solitario Canyon and Bow Ridge). Likely 
fault slip rates for these faults are at most 0.03 mm/yr, or 0.3 m or less in 10,000 years 
(BSC 2004 [DIRS 168030], Table 6). Therefore, this aspect of the FEP is not considered further. 
Implementation in the TSPA-LAIn the TSPA-LA model, the seismic scenario class evaluates the 
impact on EBS components from vibratory ground motion, fault displacement, and ground 
motion-induced post-seismic changes to the in-drift environment. The FEP is shared with 
Engineered Barrier System Features, Events, and Processes, where TSPA-LA disposition is also 
described with more emphasis on degradation effects (BSC 2004 [DIRS 169898]). Details on 
the manner of TSPA-LA disposition of included components of the seismic scenario class in the 
TSPA-LA are addressed in the model reports Seismic Consequence Abstraction (BSC 2004 
[DIRS 169183]) and the Total System Performance Assessment (TSPA) Model for the License 
Application (BSC 2004 [DIRS 168504], Section 6.5). 
Block-bounding faultsThe Solitario Canyon and Bow Ridge block-bounding faults are not 
explicitly included in the TSPA-LA abstraction for mechanical disruption of EBS components 
from fault displacement. Standoffs are required for these faults and their location is outside the 
emplacement areas of the repository (BSC 2003 [DIRS 165572], Section 7.1.3). Potential 
displacements from these faults are implicitly included in the TSPA-LA because the repository 
design is the basis for the model configuration used in the TSPA-LA. For the Solitario Canyon 
and Bow Ridge block-bounding faults, the design basis for the TSPA-LA model configuration is 
based on project requirements, discussed below. 
A Type 1 fault is a repository design term that refers to faults or fault zones that are subject to 
displacement and could have an effect on repository performance. Underground Layout 
Configuration (BSC 2003 [DIRS 165572], Section 7.1.3) states that a standoff must be 
maintained from the closest edge of a repository opening to the main trace of any Type I fault 
zones. Furthermore, the preferred location of the repository is the proposed repository block as 
defined by block bounding faults. For the above faults, waste packages will not be placed closer 
than the standoff (60 m) to the main fault trace unless a specific site impact analysis is performed 
(BSC 2003 [DIRS 165572], Sections 7.1.3 and 7.3.1). In the event that the standoff from 
repository openings to a Type I fault is waived following a site impact analysis, a standoff must 
be maintained between Type I faults and any waste package. In such cases, the standoff from the 
edge of the Type I fault or fault zone is defined as 15 m (49 feet). 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-18 November 2004 
Intrablock Faults and other Features Likely to Be Found in the RepositoryThere are known 
faults that intersect the repository, including the traces of the Sever Wash fault, Drill Hole Wash 
fault, and Pagany Wash fault. Design requirements documents have not defined standoff 
requirements for these known intrablock faults or for small faults with less than 2 m of 
cumulative offset. For example, the Subsurface Facility Description Document (BSC 2004 
[DIRS 171676], Section 3.1.1.4.8.6) refers only to Standoff from Quaternary Faults with 
Potential for Significant Displacement. The document, Underground Layout Configuration 
(BSC 2003 [DIRS 165572], Section 7.1.3), only mentions the Solitario Canyon and Bow Ridge 
faults as Type I faults. Consequently, intrablock faults and features are explicitly implemented 
within the TSPA-LA as consequences from damage to waste packages from fault displacement 
(BSC 2004 [DIRS 169183], Sections 6.7.2.1 and 6.7.2.2). 
Two intrablock faults not included in the TSPA-LA are the Ghost Dance fault and the western 
splay of the Ghost Dance fault. The Ghost Dance fault parallels the repository outside the 
eastern boundary of the repository layout. The fault is not considered in the TSPA-LA because 
no waste packages lie on these faults (BSC 2004 [DIRS 169183], Section 6.7.3). Although the 
western splay off the Ghost Dance fault intersects the repository, waste package placement in 
this contingency area is uncertain. Consequently, the splay is not considered in the TSPA-LA 
(BSC 2004 [DIRS 169183], Section 6.7.2.1). 
As discussed previously in regard to faulting at locations other than at known faults, analyses 
have determined fault intersections occur within drifts in lithophysal zones and nonlithophysal 
zones. That analysis is based on a study that quantified the likelihood of such smaller faults to 
intersect the emplacement drifts (BSC 2004 [DIRS 169183], Section 6.7.2.2). The analysis 
assumed that the density of three known faults exposed in the underground can be extrapolated 
to the configuration of the emplacement drifts and repository footprint. The analyses concluded 
there are a total of 47 tunnels and 141 locations (47 times 3) where small faults intersect the 
emplacement drifts. Thus, faulting at locations other than known faults is explicitly considered 
within the fault displacement abstraction. 
The probability of a fault displacement event severe enough to cause waste package failure is a 
function of both the specific fault (different fault displacements for a given probability) as well 
as the specific waste package design (different allowable displacements) (BSC 2004 
[DIRS 169183], Section 6.7.4). To determine the probability associated with a fault 
displacement event severe enough to cause waste package damage, fault displacement hazard 
curves are used to tabulate the predicted fault displacement as a function of probability of the 
event and the resulting fault exceedance probabilities that would cause waste package failure 
(BSC 2004 [DIRS 169183], Section 6.7.4 and Table 6.7-9). As stated above, these results 
provide fault exceedance frequencies (per year) that also result in drift collapse in the lithophysal 
zone. 
Within the TSPA-LA, fault displacement impacts EBS components through mechanical damage 
to the waste packages. In this case, the lid welds have the potential to fracture, separating the lid 
from the package and potentially exposing the entire waste form to seepage and release 
(BSC 2004 [DIRS 169183], Section 6.7). Once radionuclides are released from the EBS, flow 
and transport in the unsaturated zone and the saturated zone are based on the same models and 
algorithms as for the nominal scenario class. One exception is that changes occur in the in-drift 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-19 November 2004 
environment, caused by drift collapse in the lithophysal zones of the repository (See 
FEP 1.2.03.02.0D, Section 6.2.1.6). Another exception is that if accelerated localized corrosion 
can occur, there is no flux splitting (diversion of seepage) on the drip shield. This determines the 
fraction of the liquid flux onto the waste package that can flow inside and contact the waste 
form. A sheared drip shield will allow all seepage to pass through it for TSPA-LA (BSC 2004 
[DIRS 169183], Section 6.7.5). This FEP, shared with EBS, emphasizes details of the 
mechanical damage abstraction. 
Consequences from fault displacement and vibratory ground motion are calculated 
simultaneously in each TSPA-LA realization as damage abstractions to the waste package and 
cladding (BSC 2004 [DIRS 168504], Section 6.5.2). The abstraction for fault displacement 
described within this FEP only considers impacts caused by displacement of the tunnel axis 
severe enough to cause shearing of a waste package at the location of the discontinuity 
(BSC 2004 [DIRS 169183], Section 6.7). Shearing is assumed to occur perpendicular to the 
tunnel axis with the displacement being purely vertical. The output of the fault displacement 
abstraction is the number of waste packages failed by fault displacement and the combined 
surface area from all waste packages exposed to waste form dissolution and release (BSC 2004 
[DIRS 168504], Section 6.5). The number of waste packages failed is based on look-up tables 
correlating annual exceedance probabilities for displacement between 2  10-7 and 2  10-8 per 
year and the expected number of waste package failures for four representative waste package 
groups (BSC 2004 [DIRS 169183], Sections 6.7.4 and 6.7.5). The four representative waste 
package groups abstracted into the TSPA-LA include pressurized PWR, BWR, naval spent 
nuclear fuel (naval), and high-level radioactive waste. 
The damaged area on a waste package caused by fault displacement is determined by sampling a 
uniform distribution with a lower bound of 0 m2 and an upper bound equal to the area of the 
waste package lid (BSC 2004 [DIRS 169183], Section 6.7.5). The upper limit of each waste 
package lid area uniform distribution is a reasonable estimate for a severely crimped waste 
package that loses its lid because of cracking in the welds holding the lid in place. The lower 
limit is a reasonable estimate for a waste package that is minimally damaged, either because fault 
displacement barely exceeds the available clearance, or because a minor shear occurs at a 
location that is far from the waste package lids. The resulting damage is assumed to allow 
advective flux into the waste package (if seepage is present) and allow advective and diffusive 
transport out of the waste package lid (BSC 2004 [DIRS 169183], Sections 6.7.5 and 6.9.2). 
When a waste package fails from fault displacement, the associated EBS drip shield and fuel rod 
cladding are also assumed to fail as barriers to flow and transport. A sheared drip shield will 
allow all seepage to pass through it; that is, the damaged area is taken as the total surface area of 
the drip shield, so there is no flux splitting (diversion of seepage) on the drip shield. Similarly, 
cladding becomes 100 percent perforated in response to a fault displacement that can shear a 
waste package (BSC 2004 [DIRS 169183], Sections 6.9.2 and 6.7.5). 
The fraction of the failed surface area as a function of waste package-type surface areas is used 
in the fault displacement abstraction (BSC 2004 [DIRS 169183], Section 6.9.2). The total failed 
area from a faulting event is the weighted sum of the damage to each waste package group 
(BSC 2004 [DIRS 168504], Section 6.5). Within TSPA-LA, fault-failed waste packages are 
further grouped into two bins: commercial spent nuclear fuel (CSNF), representing PWR, BWR, 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-20 November 2004 
and naval waste packages; and co-disposal waste packages, representing high level waste 
packages. The surface area fraction is determined in a .DLL and is assigned to special CSNF 
and co-disposal waste packages TSPA-LA containers analogous to the groups used to account 
for early waste package failures. These groups combine the EBS damage fraction from ground 
motion and fault displacement and account for different environmental conditions (e.g., dripping 
or dry) (BSC 2004 [DIRS 168504], Sections 6.5.1 and 6.5.2). 
Supporting Reports: Seismic Consequence Abstraction 
MDL-WIS-PA-000003 (BSC 2004 [DIRS 169183]) 
Characterize Framework for Seismicity and Structural 
Deformation at Yucca Mountain, Nevada 
ANL-CRW-GS-000003 (BSC 2004 [DIRS 168030]) 
6.2.1.3 Seismic Ground Motion Damages EBS Components (1.2.03.02.0A) 
FEP Description: Seismic activity that causes repeated vibration of the EBS 
components (drip shield, waste package, pallet, and invert) could 
result in severe disruption of the drip shields and waste packages, 
through vibration damage or through contact between EBS 
components. Such damaged mechanisms could lead to degraded 
performance. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: Ground motion associated with seismic activity has the potential to 
disrupt the integrity of components of the EBS or waste packages. 
These events could lead to impaired container performance and/or 
breaching, with subsequent radionuclide release. Seismic ground 
motion damage is included in the TSPA-LA using damage areas on 
EBS components based on vibratory ground motions at 5  10-4, 
10-4, 10-5, 10-6, and 10-7 per year levels. Analysis model reports 
supporting the Screening Decision contain tables of included FEPs 
with pointers to more detailed background information on this FEP 
(BSC 2004 [DIRS 169183], Table 6.2-1; BSC 2004 
[DIRS 166107], Table 6-50). 
The technical basis for inclusion of this FEP includes the ground motion hazard curves 
developed for the PSHA that were extended to address ground motion during the postclosure 
period as documented in DTN: MO03061E9PSHA1.000 [DIRS 163721]. The seismic time 
histories were developed starting with the results of the PSHA (CRWMS M&O 1998 
[DIRS 103731]), but taking into account the effect of the upper 300 m of rock and soil at the site 
(the site response). These repository-level inputs for postclosure seismic evaluations are 
presented in Development of Earthquake Ground Motion Input for Preclosure Seismic Design 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-21 November 2004 
and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, Nevada 
(BSC 2004 [DIRS 170027]). 
Site-specific ground motions for five levels of annual probability of exceedance, 5  10-4, 10-4, 
10-5, 10-6, and 10-7 per year, are used to assess the postclosure analyses of damage to EBS 
components from seismic ground motion, bounded by physically realistic limits (BSC 2004 
[DIRS 169183], Sections 6.1.3 and 6.4.4). Horizontal peak ground velocity (PGV) is calculated 
for these mean annual exceedance frequencies at a Point B within the emplacement drifts, as 
described in the PSHA. 
A horizontal PGV of 0.19 m/s corresponds to the 5  10-4 per year exceedance frequency, and a 
horizontal PGV of 0.384 m/s corresponds to the 10-4 per year exceedance frequency. The 
horizontal PGV value corresponding to the 10-5 per year point on the hazard curve is 1.05 m/s. 
The horizontal PGV value for the 10-6 per year ground motions is 2.44 m/s. The horizontal PGV 
value for the 10-7 per year ground motions is 5.35 m/s (BSC 2004 [DIRS 169183], Section 4.1). 
By way of explanation, the correspondence of 2.44 m/s with 10-6 per year on the mean hazard 
curve means that all ground motion events with PGV greater than 2.44 m/s occur with a mean 
annual frequency of 10-6 per year. 
In the model report, Seismic Consequence Abstraction (BSC 2004 [DIRS 169183]), damage 
from ground motion is evaluated for the waste package and cladding. Calculations of the waste 
package and cladding damage resulting from vibratory motion are summarized in Mechanical 
Assessment of the Waste Package Subject to Vibratory Motion (BSC 2004 [DIRS 170063]). This 
document summarizes the results of a series of individual calculations that estimate damage to 
the waste package and cladding as well as present model sensitivity studies. These supporting 
calculations include analysis of the waste package vibratory motion (BSC 2004 [DIRS 167083]), 
damage assessment of the 21-PWR waste package (BSC 2003 [DIRS 162293]), determination of 
acceleration and damage to cladding (BSC 2003 [DIRS 162602]), sensitivity studies of the 
21-PWR finite element model (BSC 2004 [DIRS 170844]), and additional sensitivity studies to 
variations in input ground motion parameters (BSC 2004 [DIRS 168385], and BSC 2004 
[DIRS 170843]). 
The model report, Seismic Consequences Abstraction (BSC 2004 [DIRS 169183]), also 
summarizes structural response calculations carried out to evaluate damage to drip shield from 
vibratory ground motion, which is documented in a separate calculation, Mechanical Assessment 
of the Drip Shield Subject to Vibratory Motion and Dynamic and Static Rock Loading 
(BSC 2004 [DIRS 169753]). This document summarizes the results of a series of individual 
calculations that address damage to the drip shield from vibratory motion (BSC 2003 
[DIRS 163425]), from rockfall impact (BSC 2004 [DIRS 168993]), and quasi-static pressure 
from rockfall rubble (BSC 2004 [DIRS 170791]). Mechanical Assessment of the Drip Shield 
Subject to Vibratory Motion and Dynamic and Static Rock Loading (BSC 2004 [DIRS 169753]) 
presents kinematic analyses of drip shield separation not presented in the supporting calculations. 
In general, the Seismic Consequence Abstraction model report (BSC 2004 [DIRS 169183]), 
Mechanical Assessment of the Waste Package Subject to Vibratory Motion (BSC 2004 
[DIRS 170063]), and Mechanical Assessment of the Drip Shield Subject to Vibratory Motion and 
Dynamic and Static Rock Loading (BSC 2004 [DIRS 169753]) and their supporting calculations 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-22 November 2004 
use structural response calculations for the waste package and drip shield as the basis for 
predicting failed areas for advective flow and transport. The criteria for failure are based on a 
residual stress threshold of between 80 percent and 90 percent of the yield strength for Alloy 22 
and 50 percent of the yield strength for Titanium Grade 7. 
Structural analyses for the waste package and drip shield performed at PGV values of 0.190 m/s 
and 0.384 m/s show no damage (BSC 2004 [DIRS 169183], Section 5.1). For less frequent 
ground motions (10-6 and 10-7) per year probabilities of annual recurrence), failed areas occur in 
response to impact of the waste package on the emplacement pallet and to end-to-end impacts of 
adjacent waste packages. Consequently, damage to the waste package is included in the seismic 
scenario class for TSPA-LA. Waste package damage results are fit to a uniform cumulative 
distribution function based on 15 structural response realizations at 2.44 m/s and 5.35 m/s PGV 
(BSC 2004 [DIRS 169183], Section 6.5.1.3). To address the potential for damage at 1.05 m/s 
(10-5 probability of annual recurrence), the TSPA-LA conservatively assumes 100 percent 
cladding damage, as described in the abstraction below (BSC 2004 [DIRS 169183], 
Section 6.5.7.2). 
Similar structural response calculations were also performed to assess response of the drip shield 
to ground motions (BSC 2004 [DIRS 169753]). The set of ground motion time histories used for 
these calculations is identical with that used for the analyses of seismic-induced rockfall and 
waste package structural response (BSC 2004 [DIRS 169183], Section 6.5.4.1). 
Idealized dynamic kinematic analyses of a large number of interlocked drip shields (20 or 50) 
subjected to selected ground motion time histories with PGV of 2.44 m/s and 5.35 m/sec were 
completed. The results of these analyses are summarized as follows (BSC 2004 [DIRS 169753, 
Section 5.3.3): 
 The drip shields do not separate in any of the analyzed cases, even assuming strong 
ground motion (i.e., 10-7 probability of annual recurrence), open emplacement-drifts, and 
small friction coefficients for the drip shield-invert contact. 
 Adding the effect of rubble, resulting from drift degradation or seismic rockfall, either 
on the top of the drip shield or as a frictional restraint acting on the sides of the drip 
shield, results in stabilization of the chain of interlocked drip shields, reducing the 
magnitudes of displacements and forces in the contacts between them. In all of these 
cases, there is no predicted drip shield separation. 
Although the analyses indicate drip shield separation is physically unlikely, even in an open drift, 
it is important to consider the timing and effects of seismic-induced drift collapse and rock fall 
and the potential for drip shield separation (BSC 2004 [DIRS 169753] and BSC 2004 
[DIRS 166107] Section 6.3 and 6.4). As indicated in the following discussions involving 
FEPs 1.2.03.02.0B (Seismic-induced rockfall) and 1.2.03.02.0C (Seismic-induced drift collapse), 
partial or complete seismic-induced drift collapse and rockfall will occur in nonlithophysal and 
lithophysal zones, respectively. More importantly, partial or complete seismic-induced rockfall 
and drift collapse will occur at or below the 2.44 m/s PGV level, associated with the 10-6 annual 
exceedance probability event. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-23 November 2004 
Therefore, drip shield separation is not further considered in TSPA-LA because: 
 Interlocked drip shields move in synchronous motion to the large-period seismic ground 
motions, even in an open drift 
 Ground motion amplitudes that are sufficient to cause drip shield separation are also 
large enough to partially or completely collapse drifts in the repository 
 Drift collapse occurs within the first second or two of the arrival of these large amplitude 
ground motions (BSC 2004 [DIRS 166107], Sections 6.3.1.6.1 and 6.4.2.2.2). 
In this situation, drift collapse provides restraints on the motion of the drip shields, preventing 
differential motion that could lead to separation (BSC 2004 [DIRS 169183], Section 6.5.5). See 
FEP 1.2.03.02.0C for a related discussion. 
The drip shield will be surrounded by rock particles before significant differential displacement 
of the drip shields can occur (BSC 2004 [DIRS 169183], Section 6.5.5). Rock particles 
surrounding the drip shield provide a normal and shear confinement to the sidewalls and crown 
of the drip shield. Frictional forces existing between the footings and the invert, as well as the 
rubble and the drip shield plates, will also inhibit movement (BSC 2004 [DIRS 169183], 
Section 6.5.5; BSC 2004 [DIRS 166107], Section 6.3 and 6.4). Thus, the drip shield is partly 
surrounded by rockfall whenever separation could potentially occur, and this rockfall can occur 
near the start of the ground motions, rendering separation physically unlikely even for extreme 
ground motions. These drip shield calculations are documented in Mechanical Assessment of the 
Drip Shield Subject to Vibratory Motion and Dynamic and Static Rock Loading (BSC 2004 
[DIRS 169753]). 
Damage to the cladding has been evaluated using structural response calculations for end-to-end 
impacts of adjacent waste packages to define the axial loads on fuel assemblies. These loads are 
compared to fuel rod failure criteria based on buckling for various fuel pin designs. Comparison 
of axial loads with the failure criteria indicates that cladding will not fail from the vibratory 
ground motion at the 5  10-4 per year level (0.384 m/s); but (similar to the waste package itself) 
most, if not all, fuel pins will fail under vibratory ground motions at the 10-6 per year and the 
10-7 per year levels. Since damage is predicted for strong vibratory ground motions, this FEP is 
included in the TSPA-LA (BSC 2004 [DIRS 169183], Section 6.5.7.2). 
Implementation in the TSPA-LAThe TSPA-LA model explicitly abstracts damage to EBS 
components resulting from vibratory ground motion. This FEP is shared with Engineered 
Barrier System Features, Events, and Processes, where TSPA-LA disposition is also described 
with more emphasis on degradation effects (BSC 2004 [DIRS 169898]). Details on the manner 
of TSPA-LA disposition of included components of the seismic scenario class in the TSPA-LA 
can be found addressed in the model reports Seismic Consequence Abstraction (BSC 2004 
[DIRS 169183]) and the Total System Performance Assessment (TSPA) Model for the License 
Application (BSC 2004 [DIRS 168504], Section 6.5). 
Within the TSPA-LA, the damaged area on a waste package is abstracted as a uniform 
distribution with a lower bound of 0 and an upper bound that is a linear function of PGV 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-24 November 2004 
(BSC 2004 [DIRS 169183], Section 6.9.2). The waste package damaged area is larger than the 
effective area susceptible to accelerated stress corrosion cracking (BSC 2004 [DIRS 169183], 
Section 6.3.2). The actual damaged area on the waste package is represented as a network of 
stress corrosion cracks. 
In the abstraction, PGV values are first sampled from a hazard curve. The hazard curve is 
represented within TSPA-LA as a 1-D lookup table for PGV values associated with mean annual 
exceedance frequencies between 10-4 and 10-8 per year. This range spans the response of the 
system, from no damage at 10-4 annual exceedance probability to the regulatory limit at 10-8 
annual exceedance probability per year (BSC 2004 [DIRS 169183], Section 6.9.1.1). The 
horizontal PGV value corresponding to the 10-4 annual exceedance probability point on the 
hazard curve is 0.384 m/s (BSC 2004 [DIRS 169183], Section 5.1). 
The value of PGV used for a particular realization results from applying a second uniform 
distribution used to bound unrealistic results, a uniform distribution defined as ranging from 
1.5 m/s and 5 m/s. The value of PGV is the minimum value obtained from a 1-D look-up table 
associated with mean annual exceedance frequencies between 10-4 and 10-8 per year or obtained 
using the bounding distribution (BSC 2004 [DIRS 169183], Section 6.9.1.2). 
The damage abstraction for a waste package is defined by a uniform distribution with a lower 
bound of 0 percent damaged area and an upper bound that is a linear function of PGV (BSC 2004 
[DIRS 169183], Section 6.9.2). The waste package damage abstraction is applied to all waste 
packages in the repository, excluding those packages that experience early time failures from 
manufacturing defects or from defects that occur during emplacement (BSC 2004 
[DIRS 169183], Section 6.5.1.3). The sampled value of the uniform distribution (for each 
realization) is converted into an effective area for flow and transport. 
Damage to cladding is explicitly implemented within the TSPA-LA. Cladding experiences 
complete failure (i.e., 100 percent of the cladding is perforated) at the time of the seismic event 
for ground motions with PGV amplitude of 1.05 m/s, or greater. As stated earlier, 1.05 m/s PGV 
corresponds to the 10-5 per year exceedance frequency (BSC 2004 [DIRS 169183], Section 4.1). 
The damage to the cladding is expressed as a percentage of perforated fuel rods (BSC 2004 
[DIRS 169183], Section 6.9.2). The TSPA abstraction for damage to the cladding is represented 
in the TSPA-LA as 1-D table lookup as a function of the value of PGV for a particular 
realization. 
Within the TSPA-LA, cladding damage is always zero for PGV values less than 0.55 m/s and 
always 100 percent for PGV values greater than 1.05 m/s. For values between 0.55 m/s and 
1.05 m/s, percent damage is estimated by linear interpolation on PGV (BSC 2004 
[DIRS 169183], Section 6.9.2). Within TSPA-LA, this damage is applied to all fuel assemblies, 
except for assemblies with initial clad damage or initial clad failures. There is no spatial 
variability in the damage because damage to the cladding occurs within all waste packages 
(BSC 2004 [DIRS 169183], Section 6.5.7.3). 
Within the TSPA-LA, the degree of ground motion damage is assumed to apply to all waste 
packages and CSNF cladding in the repository (BSC 2004 [DIRS 169183], Section 6.5.3, 6.5.7, 
and 6.9.2). Within the TSPA-LA, the surface area fraction is calculated assuming two CSNF and 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-25 November 2004 
co-disposal waste package containers analogous to the groups used to account for early waste 
package failures. These groups combine the EBS damage fraction from ground motion and fault 
displacement and account for different environmental conditions (e.g., dripping or dry) 
(BSC 2004 [DIRS 168504], Sections 6.5.1 and 6.5.2). 
Supporting Reports: Development of Earthquake Ground Motion Input for Preclosure 
Seismic Design and Postclosure Performance Assessment of a 
Geologic Repository at Yucca Mountain, Nevada 
MDL-MGR-GS-000003 (BSC 2004 [DIRS 170027]) 
Seismic Consequence Abstraction 
MDL-WIS-PA-000003 (BSC 2004 [DIRS 169183]) 
Mechanical Assessment of the Drip Shield Subject to Vibratory 
Motion and Dynamic and Static Rock Loading 
CAL-WIS-AC-000002 (BSC 2004 [DIRS 169753]) 
Mechanical Assessment of the Waste Package Subject to Vibratory 
Ground Motion 
CAL-WIS-AC-000001 (BSC 2004 [DIRS 170063]) 
Drift Degradation Analysis ANL-EBS-MD-000027 (BSC 2004 
[DIRS 166107]) 
6.2.1.4 Seismic-Induced Rockfall Damages EBS Components (1.2.03.02.0B) 
FEP Description: Seismic activity could produce jointed-rock motion and/or changes 
in rock stress leading to enhanced rockfall that could impact drip 
shields, waste packages, or other EBS components. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: Vibratory ground motions can cause failure of the host rock around 
emplacement drifts. This motion could result in damage to the drip 
shields through mechanical impact mechanisms and possibly the 
waste packages (if the drip shields fail) via increased seepage 
through a damaged or separated drip shield. Rockfall calculations 
indicate potential consequences of rockfall occur in both the 
lithophysal and nonlithophysal zones substantially below the 10-6 
annual probability of exceedance (PGV 2.44 m/s) (BSC 2004 
[DIRS 166107], Sections 6.3 and 6.4). Note that subsequent 
analyses summarized below indicate rockfall occurring as small 
rubble or large blocks will not compromise engineered barriers, 
and therefore this FEP is screened out on the basis of low 
consequence. 
The term, rockfall, as used in this discussion of the technical basis for inclusion of this FEP, is 
intended to mean the dislodging of relatively fewer and larger blocks of rock from the sides or 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-26 November 2004 
crown of an emplacement drift. In contrast, an en masse fall of rock fragments constitutes drift 
collapse for FEPs purposes. Seismic-induced drift collapse is addressed as FEP 1.2.03.02.0C in 
Section 6.2.1.5. Due to the different stratigraphic units that the emplacement drifts will transect, 
both lithophysal and nonlithophysal rock types are explicitly considered. The ground motion 
hazard curves developed for the PSHA were extended to address ground motion during the 
postclosure period as documented in DTN: MO03061E9PSHA1.000 [DIRS 163721]. The 
seismic time histories were developed starting with the results of the PSHA (CRWMS M&O 
1998 [DIRS 103731]), but taking into account the effect of the upper 300 m of rock and soil at 
the site (the site response). These repository-level inputs for postclosure seismic evaluations are 
presented in Development of Earthquake Ground Motion Input for Preclosure Seismic Design 
and Postclosure Performance Assessment of a Geologic Repository at Yucca Mountain, Nevada 
(BSC 2004 [DIRS 170027]). 
Site-specific ground motions for five levels of annual probability of exceedance, 5  10-4, 10-4, 
10-5, 10-6, and 10-7 per year, are used to assess the postclosure analyses of damage to EBS 
components from seismic ground motion, seismic-induced rockfall, as well seismic-induced drift 
collapse (BSC 2004 [DIRS 166107], Sections 6.3.1.2.1 and 6.4.2.2). 
In general, vibratory ground motions can cause failure of the host rock around the emplacement 
drifts. Two potential sources of damage to the drip shield from the en masse rockfall have been 
considered in the lithophysal zone. The first is damage from the individual rubblized rock 
fragments that fall onto and impact the drip shield and is emphasized in this FEP. The second 
potential source of damage in the lithophysal zone is the static load on the drip shield from 
rubble resulting from drift collapse. This second source of damage is emphasized in 
FEP 1.2.03.02.0C. 
This FEP also evaluates the mechanical response of the drip shield to impacts from large rock 
blocks in the nonlithophysal zone (BSC 2004 [DIRS 169183], Section 6.6.1 and 6.6.2). 
Geologic structure and rock strength define the failure mode in the nonlithophysal rock, resulting 
in a greater distribution of sizes of rock blocks. In lithophysal zones, the rock mass has lower 
compressive strength due to the presence of closely-spaced lithophysal void spaces that permeate 
the rock mass in addition to the ubiquitous, closely-spaced fracture network. The rubble 
resulting from failure is expected to be characteristically smaller in size relative to 
nonlithophysal zones due to the presence of these lithophysal voids. 
Impact damage to the Titanium Grade 7 plates of the drip shield may include tearing or denting 
of drip shield surface. Mechanical response calculations described in this FEP are used to 
determine the drip shield areas where the residual tensile stress exceeds the threshold value 
(50 percent of yield strength) for the Titanium Grade 7 drip shield surface (BSC 2004 
[DIRS 169183], Section 6.3.6). 
For 10-4 
per year ground motions, little damage is predicted in lithophysal zones, even in 
unsupported areas of a drift (BSC 2004 [DIRS 166107], Section 6.4.2.2). Fall of rock fragments 
in the lithophysal zone was also examined for less frequently occurring ground motions 
(i.e., 10-5, 10-6, and 10-7 per year probabilities of annual recurrence). Peak ground velocities of 
about 1.5 m/sec result in an approximate damage level below 5 m3 of falling rock fragments per 
meter of emplacement drift length. In practical terms, this damage level ranges from minor 

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ANL-WIS-MD-000005 REV 02 6-27 November 2004 
spalling, to damage characterized by rock particles filling the invert along the sides of the drip 
shield. Peak ground velocities from approximately 1.5 to 2 m/sec result in approximate damage 
levels from 5 to 15 m3 of falling rock fragments per meter of emplacement drift length. In 
practical terms, this damage level is characterized by rock particles covering the sides of the drip 
shield to approximately the height of the drip shield. Rock particles may also cover the top of 
the drip shield. Peak ground velocities in excess of about 2.0 m/sec result in damage levels 
above 15 m3 of falling rock fragments per meter of emplacement drift length. Complete collapse 
of the tunnel is modeled to occur at about the 10-6 hazard level (BSC 2004 [DIRS 166107], 
Section 6.4.2.2.2). 
As stated, rock fragments associated with the lithophysal zone that contact the drip shield are 
estimated to be relatively small. Fragments have particle sizes on the order of centimeters to 
decimeters (BSC 2004 [DIRS 169183], Section 6.6.2.1). The Seismic Consequence Abstraction 
(BSC 2004 [DIRS 169183], Section 6.6.1.2) provides an example of the low consequence that 
these small fragments have upon impact with the drip shield. Consider a fragment that (for 
simplicity) is a cube 0.1 m on a side. The volume of this fragment is 0.001 m3 
and its mass is 
approximately 2 kg (0.0023 MT), assuming a tuff density of approximately 2,000 kg/m3. The 
terminal velocity of this fragment is 7.7 m/s, for a 3-m drop under gravitational acceleration and 
the associated kinetic energy is 59 Joules. The seismic abstraction model report (BSC 2004 
[DIRS 169183], Table 6.6-2, Section 6.6.1.2) shows that a fragment with similar kinetic energy 
does not produce a failed area on the surface of the drip shield. Consequently, expected rock 
fragment masses (e.g., 0.0023 MT) associated with the lithophysal zone do not damage drip 
shields. Damage to the drip shield from falling rock fragments in the lithophysal zone is 
neglected for TSPA-LA on these bases. 
Potential drip shield damage from rockfall impact in the nonlithophysal rock types were also 
analyzed. Results indicate that vibratory ground motions have the potential to produce larger 
rock blocks that free-fall at gravitational velocities (calculations of impact energy account for the 
relative velocity of the drip shield and rock block during a seismic event). Relatively few blocks 
dislodge at the 5  10-4 per year ground motion level (BSC 2004 [DIRS 169183], Section 6.6.1), 
but numerous rock blocks dislodge for the 10-6 per year and the 10-7 per year ground motion 
levels. Rock blocks have the potential to deform the drip shield, resulting in accelerated stress 
corrosion cracking in areas that exceed the residual stress threshold for Titanium Grade 7 
(BSC 2004 [DIRS 169183], Section 6.3.1 and 6.6.1). Such blocks also have the potential to 
result in immediate puncture or tearing of the drip shield if the localized strain exceeds the 
ultimate tensile strain limits for the 15 mm thick Titanium Grade 7 surface sheets. 
The Drift Degradation model report (BSC 2004 [DIRS 166107], Section 6.3) provides a detailed 
description of the nonlithophysal rockfall calculations performed with the 3DEC, 
three-dimensional discontinuum computer program. Results for the preclosure hazard level of 
10-4 annual probability of exceedance ground motion indicate a total of 535 blocks per km of 
drift length (BSC 2004 [DIRS 166107], Section 6.3.1.6.1, Tables 6-26 and 6-27). For 10-5
, 10-6, 
and 10-7 
per year ground motions, results indicate 1,414 blocks, 2,238 blocks, and 3079 blocks 
per km of emplacement drift length. Median rock sizes range in weight from 0.10 to 0.15 MT. 
Nonlithophysal rock blocks are generally larger than rock fragments in the lithophysal zone and 
drift profiles show more localized areas of rock failure (BSC 2004 [DIRS 166107], 
Sections 6.3.4 and 8.1). In general, in nonlithophysal rock, rockfall volumes are sufficient to 

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ANL-WIS-MD-000005 REV 02 6-28 November 2004 
accumulate rock blocks adjacent to the drip shield; however, seismic shaking is not predicted to 
result in complete collapse of the drift (BSC [DIRS 169183], Section 6.8.3). 
Structural response calculations of damage to the drip shield from the impact of individual rock 
blocks incorporate the potential for corrosion to degrade the drip shield over the first 20,000 years 
after repository closure. The thickness of the drip shield plates is assumed to be reduced by 2 mm 
(BSC 2004 [DIRS 169183], Section 6.6.1.2). Calculations assume mechanical properties of the 
drip shield materials at 150C to represent the potential degradation in moduli and strength if a 
seismic hazard occurs during the initial thermal pulse after repository closure. The calculations 
model six representative rock blocks, ranging in weight from 0.11 MT to 14.5 MT2. Rock block 
kinetic energies generated by ground motions with PGV between 2.44 m/s and 5.35 m/s vary 
depending on weight and relative velocities of the drip shield and the falling rock block. 
These blocks impact the drip shield from three different angles: vertically downward onto the top 
of the drip shield, at a 60 angle (with the horizontal) onto the transition region between the top 
and side of the drip shield, and horizontally into the side wall. The model assumes that the 
blocks impact the drip shield edge-on (perpendicular) to maximize damage potential. A key 
result from this suite of calculations is that the maximum vertical displacement in the drip shield 
components takes place in the longitudinal stiffener. This result occurs in response to the 
vertical impact of the 11.5 MT rock block, which has the highest kinetic energy at impact. The 
drip shield does not buckle or collapse from this impact. It follows that the drip shield continues 
to provide a mechanical barrier against rockfall for the waste package and cladding. 
Because the damaged areas remain physically intact, the most likely damage mechanism 
affecting the Titanium Grade 7 plates of the drip shield is accelerated stress corrosion cracking 
(BSC 2004 [DIRS 169183], Section 6.5.4). The deformed or dented region consists of 
individual, but complex, branching cracks with high surface roughness and tortuosity. This 
physical morphology has little potential for advective flux through the cracks because of infilling 
of narrow apertures with corrosion products. A calculation of the expected rate of crack 
plugging due to evaporation-induced precipitation of calcite has been performed for a pore water 
of typical composition dripping onto a drip shield. Cracks are sealed within a few hundred years 
when water is allowed to flow through the cracks at the expected (very low) rate for thin film 
flow. After a crack is plugged with precipitates, the magnitude of the liquid flux through the 
crack will become insignificant for two reasons. First is the lack of a significant pressure head or 
gradient to drive liquid through the crack. Second is high tortuosity and roughness of the crack 
geometry. Damage to the drip shield from rockfall is neglected for TSPA-LA on these bases 
(BSC 2004 [DIRS 169183], Section 6.5.4). 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
2 The Drift Degradation Analysis (BSC 2004 [DIRS 166107]) shows that in the nonlithophysal rock at the 10-6 
annual exceedance probability, the median dislodged rock block mass is 0.13 MT with a standard deviation of 1.3 
MT, a median relative impact velocity of 2.97 m/sec and a median impact energy of 576 joules. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-29 November 2004 
6.2.1.5 Seismic-induced Drift Collapse Damages EBS Components (1.2.03.02.0C) 
FEP Description: Seismic activity could produce jointed-rock motion and/or changes 
in rock stress leading to enhanced drift collapse that could impact 
drip shields, waste packages, or other EBS components. Possible 
effects include both dynamic and static loading. 
Screening Decision: Excluded - Low Consequence 
Screening Argument: The potential consequences of seismic-induced drift collapse 
require two preceding factors: (1) that drift collapse occurs, 
and (2) that the weight of the resulting collapsed rock 
rubble is sufficient to cause structural failure of the drip 
shields. Drift degradation analysis covered in the following 
discussion, indicates that drift collapse in lithophysal units can 
occur. Note that subsequent analyses summarized below show that 
drift collapse in lithophysal units will not affect the structural 
integrity of the drip shield. Analyses subsequent to the drift 
degradation analysis also indicate that complete drift collapse in 
nonlithophysal units is expected under seismic or time-dependent 
degradation but is not of concern. 
The term drift collapse, as used in this discussion of the technical basis for exclusion of this 
FEP, is intended to mean an en masse fall of rock fragments into an emplacement drift. In 
contrast, a rockfall is the dislodging of relatively fewer and larger blocks of rock from the 
sides or crown of an emplacement drift. Seismic-induced rockfall is addressed as 
FEP 1.2.03.02.0B in Section 6.2.1.4. Due to the different stratigraphic units that the 
emplacement drifts will transect, both lithophysal and nonlithophysal rock types are explicitly 
considered. The ground motion hazard curves developed for the PSHA were extended to address 
ground motion during the postclosure period as documented in DTN: MO03061E9PSHA1.000 
[DIRS 163721]. The seismic time histories were developed starting with the results of the PSHA 
(CRWMS M&O 1998 [DIRS 103731]), but taking into account the effect of the upper 300 m of 
rock and soil at the site (the site response). These repository-level inputs for postclosure seismic 
evaluations are presented in Development of Earthquake Ground Motion Input for Preclosure 
Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca 
Mountain, Nevada (BSC 2004 [DIRS 170027]). 
Site-specific ground motions for five levels of annual probability of exceedance, 5 x 10-4, 10-4, 
10-5, 10-6, and 10-7 per year, are used to assess the postclosure analyses of damage to EBS 
components from seismic ground motion, seismically-induced rockfall, as well 
seismically-induced drift collapse (BSC 2004 [DIRS 166107], Sections 6.3.1.2.1 and 6.4.2.2). 
This FEP addresses rockfall as in FEP 1.2.03.02.0B, but the emphasis is on the static load on the 
drip shield caused by drift collapse within lithophysal zones. As discussed in FEP, 1.2.03.02.0B, 
seismic-induced rockfall volumes in nonlithophysal rock, while sufficient to accumulate rock 
blocks adjacent to the drip shield, is not expected to result in complete collapse of the drift. 

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ANL-WIS-MD-000005 REV 02 6-30 November 2004 
As concluded in FEP 1.2.03.02.0B, at the higher hazard levels (e.g., greater than 10-5 per year), 
the response of lithophysal zones to higher ground motion ranges from minor spalling, to filling 
the invert along the sides of the drip shield or coverage of the top of the drip shield. Within 
lithophysal zones, rock fragments that contact the drip shield are relatively small, and are 
governed by the inherent, closely-spaced ubiquitous fracture network and lithophysae spacing. 
Fragments have particle sizes on the order of centimeters to decimeters (BSC 2004 
[DIRS 169183], Section 6.6.2.1). As discussed in FEP 1.2.03.02.0B, the impact of rock particles 
in lithophysal zones has no effect on the integrity of the drip shields. However, the accumulation 
of rock particles, up to and including drift collapse, in the lithophysal zones can also impose a 
quasi-static load on the drip shield from the weight of the rubble that fills the drifts as a result of 
one or more collapse events. 
Rubble loads to the drip shield were estimated from collapse simulations using a discontinuum 
numerical model (BSC 2004 [DIRS 166107], Section 6.4.2.5). Six realizations of the collapse 
response and loading to the drip shield structure were conducted and used as input to a 
three-dimensional finite element structural analysis of the drip shield (BSC 2004 [DIRS 166107], 
Section 6.4.2.5, Figure 6-174; BSC 2004 [DIRS 169753], Section 5.4.3). These analyses 
indicate that the drip shield is structurally stable under loads predicted from all scenarios of drift 
collapse. Further analyses were performed to provide an approximate estimate of the safety 
margin against collapse. These analyses involved increasing the density of the rock rubble, 
thereby progressively increasing the vertical and lateral loading applied to the drip shield. These 
calculations found that the drip shield eventually undergoes excessive deformation (without 
sudden collapse) due to formation of a plastic hinge on the supporting leg beams. The average 
vertical load that results in this excessive plastic deformation is approximately 3.25 times the 
average vertical pressure from the six collapse realizations described above (BSC 2004 
[DIRS 169753], Section 5.4.3). Since the drip shield is stable for reasonably-expected collapsed 
rubble pressures, and since an additional safety margin of several times exists, the effect of drift 
collapse in lithophysal zones and associated static load is screened from the TSPA-LA on the 
basis of low consequence. 
While the static load is screened from the TSPA-LA, the cumulative effect of seismic-induced 
drift collapse will have an effect on drip shield separation. As discussed in the response to 
FEP 1.2.03.02.0A (Seismic ground motion damages EBS components), drip shield separation 
resulting from vibratory motion is not likely to result in any consequence in an open drift as a 
result of synchronicity of motion of the interlocked drip shields. However, kinematic analyses 
presented in Mechanical Assessment of the Drip Shield Subject to Vibratory Motion and 
Dynamic and Static Rock Loading (BSC 2004 ([DIRS 169753], Section 5.3.3) show that the 
weight or frictional resistance of rubble against the drip shield completely prevents separation, 
even at ground motions representative of annual exceedance frequency of 10-7 per year, or 
5.35 m/sec PGV level. 
Ground motion amplitudes sufficient to separate drip shields are large enough to partially or 
completely collapse drifts in both lithophysal and nonlithophysal zones of the repository 
(BSC 2004 [DIRS 169183], Section 6.5.4). In addition, given that smaller seismic events with a 
probability rate of 10-5 per year are more likely to occur than extreme events, smaller events will 
contribute to the buildup of rock fragments around the drip shield before an extreme event 
occurs. Since multiple higher probability (e.g., 10-5 per year) events are more likely than single 

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ANL-WIS-MD-000005 REV 02 6-31 November 2004 
lower probability (e.g., 10-7 per year) events, it is reasonable to assume that significant rubble 
would exist in the drift to confine the drip shield prior to the occurrence of an event that would 
result in drip shield displacement (BSC 2004 [DIRS 169753]). The presence of even small 
frictional or gravitational loads has been shown to restrain the relative motion between adjacent 
drip shields (BSC [DIRS 169183], Section 6.5.4). Large blocks or small fragments around the 
drip shields cause sufficient frictional loads on the sides of the drip shield to pin the drip shield in 
place. See FEP 1.2.03.02.0A for further discussion. 
The Drift Degradation model report (BSC 2004 [DIRS 166107], Section 6.3) provides a detailed 
description of the nonlithophysal rockfall calculations with the 3DEC three-dimensional 
discontinuum computer program. As stated in FEP 1.2.03.02.0B, numerous rock blocks may 
dislodge for the 10-6 per year and the 10-7 per year ground motion levels. For 10-5
, 10-6, and 
10-7 
per year ground motions, results indicate 1,414 blocks, 2,238 blocks, and 3,079 blocks per 
km of emplacement drift length (BSC 2004 [DIRS 166107], Section 6.3.1.6.1, Tables 6-26 and 
6-27). These larger postclosure ground motions in nonlithophysal zones are characterized by 
localized areas of rock failure, in some cases sufficient to cover the drip shield (BSC 2004 
[DIRS 166107], Section 8.1). However, as stated, seismic-induced rockfall in nonlithophysal 
rock is not expected to result in complete collapse of the drift. Due to this consideration and the 
larger size of rock blocks, calculations have emphasized the impact of the size and kinetic energy 
of these larger blocks on the integrity of the drip shield, rather than the effect of static load 
(BSC 2004 [DIRS 166107], Section 6.6.1). 
Structural response calculations of damage to the drip shield from the impact of individual rock 
blocks model six representative rock blocks, ranging in weight from 0.11 MT to 14.5 MT3 
(BSC 2004 [DIRS 169183], Section 6.6.1.2). Rock block kinetic energies generated by ground 
motions with PGV between 2.44 m/s and 5.35 m/s vary depending on weight and relative motion 
of the drip shield. As described in FEP 1.2.03.02.0B, a key result from this suite of calculations 
is that the drip shield does not buckle or collapse from this impact. It follows that the drip shield 
continues to provide a mechanical barrier against rockfall for the waste package and cladding. 
Consequently, the affect of drift collapse within nonlithophysal zones is considered low 
consequence and is not included in the TSPA-LA. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.1.6 Seismic-Induced Drift Collapse Alters In-Drift Thermohydrology (1.2.03.02.0D) 
FEP Description: Seismic activity could produce jointed-rock motion and/or changes 
in rock stress leading to enhanced drift collapse and/or rubble infill 
throughout part or all of the drifts. Drift collapse could impact 
3 The Drift Degradation Analysis (BSC 2004 [DIRS 166107]) shows that in the nonlithophysal rock at the 10-6 
annual exceedance probability, the median dislodged rock block mass is 0.13 MT with a standard deviation of 1.3 
MT, a median relative impact velocity of 2.97 m/sec and a median impact energy of 576 joules. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-32 November 2004 
flow pathways and condensation within the EBS, mechanisms for 
water contact with EBS components, and thermal properties within 
the EBS. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: The potential consequences of drift collapse require two factors: 
(1) that drift collapse occurs, and (2) that the volume or 
amount of collapse is sufficient to change the drift profile such 
that seepage into the drift and thermal properties are significantly 
affected. Changes to the seepage and in-drift thermohydrology due 
to seismic-induced changes in the drift profile are included in the 
TSPA-LA. Analysis model reports supporting the Screening 
Decision contain tables of included FEPs with pointers to more 
detailed background information on this FEP (BSC 2004 
[DIRS 169183], Table 6.2-1; BSC 2004 [DIRS 166107], 
Table 650). 
The term drift collapse, as used in this discussion of the technical basis for inclusion of this 
FEP, is intended to mean an en masse fall of rock fragments into an emplacement drift. In 
contrast, a rockfall is the dislodging of relatively fewer and larger blocks of rock from the 
sides or crown of an emplacement drift. Seismic-induced rockfall is addressed as 
FEP 1.2.03.02.0B in Section 6.2.1.4. Site-specific ground motions for five levels of annual 
probability of exceedance, 5  10-4, 10-4, 10-5, 10-6, and 10-7 per year are used to assess the 
postclosure analyses of damage to EBS components from seismic ground motion, as well as 
rockfall and drift collapse (BSC 2004 [DIRS 166107], Sections 6.3.1.2.1 and 6.4.2.2). 
The ground motion hazard curves developed for the PSHA were extended to address ground 
motion during the postclosure period as documented in DTN: MO03061E9PSHA1.000 
[DIRS 163721]. The seismic time histories were developed starting with the results of the PSHA 
(CRWMS M&O 1998 [DIRS 103731]), but taking into account the effect of the upper 300 m of 
rock and soil at the site (the site response). These repository-level inputs for postclosure seismic 
evaluations are presented in Development of Earthquake Ground Motion Input for Preclosure 
Seismic Design and Postclosure Performance Assessment of a Geologic Repository at Yucca 
Mountain, Nevada (BSC 2004 [DIRS 170027]). 
The Drift Degradation Analysis (BSC 2004 [DIRS 166107]) evaluated rockfall and drift-collapse 
effects related to seismic-induced ground motion. As discussed in FEP 1.2.03.02.0C 
(Seismic-induced drift collapse damages EBS components), lithophysal and nonlithophysal rock 
units have two fundamentally different failure modes under seismic loading. The collapse of 
drifts from high amplitude ground motion in the lithophysal zones can fill the drifts with rubble, 
potentially altering the hydrologic and thermal environment around the EBS components. This 
FEP is therefore included, and changes to in-drift thermohydrology associated with drift collapse 
are addressed in the TSPA-LA. 

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ANL-WIS-MD-000005 REV 02 6-33 November 2004 
In lithophysal areas with compete drift collapse, the shape of the drift is altered and the drift is 
filled with a rubble, resulting in the potential process-level changes in and around the engineered 
barrier system. Anticipated post-seismic changes in the local in-drift environment include 
(BSC 2004 [DIRS 169183], Section 6.8): 
 Increase in seepage mainly because of the larger size and the different shape of 
collapsed drifts (e.g., BSC 2004 [DIRS 169131], Section 6.3.1) 
 Increase in temperatures of the drip shield and waste package because rubble provides 
an insulating blanket on top of the drip shield 
 Increase in localized corrosion, and increase in dissolution rates of CSNF and high-level 
radioactive waste glass with increasing temperature. 
Seepage estimates have been made for collapsed drift profiles in lithophysal rocks provided in 
DTN: MO0306MWDDPPDR.000 [DIRS 164736], which were determined from analyses 
summarized in BSC 2004 ([DIRS 166107], Appendix R). The seepage estimates also take into 
account the increased rock mass permeability in the periphery of the collapsed drift as well the 
reduced capillary strength of the drift due to the presence of rubble. Even though a collapsed 
drift may lead to significantly different seepage behavior, capillary barrier effects still give rise 
to considerable flow diversion at the interface between the solid rock and the rubble-filled drift. 
The worst-case (largest collapsed diameter) drift profile predicted by the drift collapse analyses 
(BSC 2004 [DIRS 166107]) of 11-m diameter circular profile was selected for the collapsed 
lithophysal drifts. This drift profile results in more seepage due to: 
 The total amount of percolation flux arriving at the drift increases with the horizontal 
drift size (footprint) 
 Flow diversion is less effective for a larger drift. 
Systematic seepage simulations were conducted for the collapsed drift case using a full set of 
parametric variations of rock mass parameters, including capillary strength and percolation flux 
(BSC 2004 [DIRS 169131], Section 6.4.2.4). 
The effects of local rockfall in nonlithophysal zones and related drift shape changes are rather 
small (BSC 2004 [DIRS 169131], Section 6.4.2.4.2). There is no explicit change in the seepage 
abstraction in the nonlithophysal zones because rockfall is localized and because there is limited 
impact on the shape and size of the drift profile (BSC 2004 [DIRS 166107], Section 6.3.1). In 
the nonlithophysal zones, some rockfall and relatively minor changes to drift profiles occur as a 
result of seismic events with 2.44 and 5.35 m/s PGV levels. Seepage analyses using the 
degraded drift profiles from the 75th percentile and greatest-degradation cases of the rockfall 
analyses were performed (BSC 2004 [DIRS 169131] Section 6.4.2.4). These analyses show that 
the impact of drift shape change due to moderate drift degradation representative of the 
nonlithophysal rock results in negligible differences to the non-degraded, circular drift. Except 
for local wedge-type rockfall, the drifts in nonlithophysal units remain intact openings with the 
horizontal extent essentially unchanged. Consequently, there is no explicit change in the seepage 
flux into the emplacement drifts in the nonlithophysal zones after a seismic event (BSC 2004 

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ANL-WIS-MD-000005 REV 02 6-34 November 2004 
[DIRS 169183], Section 6.8.1). The seepage abstraction does include an implicit enhancement 
factor for limited collapse of the emplacement drifts in nonlithophysal zones. The nominal 
seepage abstraction currently includes an enhancement factor of 20% to account for uncertainties 
related to local rockfall in the nonlithophysal units, and this enhancement factor is deemed 
adequate to address the impact of local rockfall related to seismic events (BSC 2004 
[DIRS 169131], Section 6.5.1.5). The seepage response determined for the nominal, circular 
drift profile is used in the seismic scenario for emplacement drifts in the nonlithophysal rocks 
(BSC 2004 [DIRS 169131], Section 6.4.2.4). 
Implementation in the TSPA-LAIn the TSPA-LA model, the seismic scenario class evaluates the 
impact on EBS components from vibratory ground motion, fault displacement, and ground 
motion-induced drift collapse. The FEP is shared with Engineered Barrier System Features, 
Events, and Processes, where TSPA disposition is also described with more emphasis on 
degradation effects (BSC 2004 [DIRS 169898]). Details on the manner of TSPA-LA disposition 
of included components of the seismic scenario class in the TSPA-LA are addressed in the model 
reports, Seismic Consequence Abstraction (BSC 2004 [DIRS 169183]) and the Total System 
Performance Assessment (TSPA) Model for the License Application (BSC 2004 [DIRS 168504], 
Section 6.5). 
As suggested above, seismically-modified seepage in lithophysal zones is explicitly included in 
the TSPA-LA abstraction. Seismically modified seepage is explicitly included by modifying the 
seepage flux in lithophysal zones following seismic-induced drift collapse (BSC 2004 
[DIRS 169183], Section 6.9.2). For purposes of TSPA implementation of the seepage 
abstraction, drift collapse is assumed to occur at all ground motions with a PGV greater than 
0.384 m/s. As indicated above, the 10-6 hazard level (PGV of 2.0 m/s) is considered a more 
reasonable threshold for drift collapse in the lithophysal zones (BSC 2004 [DIRS 169183], 
Section 6.8.1). Modified seepage is determined by using degraded drift seepage response 
surfaces in the form of look-up tables as a function of seepage-relevant parameters for 
lithophysal rock units (BSC 2004 [DIRS 169183], Section 6.8.1). The seepage simulations 
referred to above are the technical basis for the seepage look-up tables. 
In addition to switching to the seepage table for collapsed drifts, a temperature constraint is also 
applied to the seepage flux after drift collapse in the lithophysal zones. Specifically, the seepage 
onto the waste package is set to zero for the period of above-boiling temperatures by using a 
100C threshold temperature. This constraint implies that seepage can enter the drift and be 
diverted through the rubble to the invert beneath the waste package, but cannot contact the waste 
package surface until the waste package surface temperature drops below 100C. This threshold 
temperature is based on a sensitivity study of seepage arrival times at the drip shield crown for a 
collapsed drift that is filled with rubble (BSC 2004 [DIRS 169183], Section 6.8.1). This study 
considers rubble with high and low values of thermal conductivity and seepage magnitudes that 
vary between 100 liters/year/WP and 10,000 liters/year/WP. The temperature threshold of 
100C is a reasonable upper bound to the ranges of waste package temperature that significantly 
delay the arrival of seepage at the drip shield crown. In nonlithophysal zones, the temperature 
constraint on seepage is the same as that used for intact drifts, wherein seepage does not enter the 
emplacement drifts until the drift wall temperature drops below 100C (BSC 2004 
[DIRS 169183], Section 6.8.1). 

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ANL-WIS-MD-000005 REV 02 6-35 November 2004 
Temperature and relative humidity affecting the waste packages after drift collapse in the 
lithophysal zones is implemented in TSPA at all ground motions with a PGV greater than 
0.384 m/s (BSC 2004 [DIRS 169183], Section 6.9.2, number 14). The temperature and relative 
humidity of the waste package after drift collapse are defined by the calculations with the 
multiscale thermohydrologic model (BSC 2004 [DIRS 169183], Section 6.8.3). These 
calculations predict the changes in temperature and relative humidity for eight different waste 
package emplacement configurations using bounding (high or low) values for the thermal 
conductivity of the rubble surrounding the drip shield. These configurations are intended to 
define the temperature and relative humidity changes, which are then applied to the CSNF and 
co-disposal waste package groups used in TSPA-LA (BSC 2004 [DIRS 169183], Section 6.9.2). 
The fraction of waste packages affected is output from a TSPA-LA .DLL (BSC 2004 
[DIRS 168504], Section 6.5.1.3). Within the TSPA-LA, additional TSPA submodels address 
attendant effects on degradation processes and flow and transport within the engineered barrier 
system (BSC 2004 [DIRS 169183], Sections 6.8 and 6.9.2). 
Supporting Reports: Development of Earthquake Ground Motion Input for Preclosure 
Seismic Design and Postclosure Performance Assessment of a 
Geologic Repository at Yucca Mountain, Nevada 
MDL-MGR-GS-000003 (BSC 2004 [DIRS 170027]) 
Drift Degradation Analysis 
ANL-EBS-MD-000027 (BSC 2004 [DIRS 166107]) 
Seismic Consequence Abstraction 
MDL-WIS-PA-000003 (BSC 2004 [DIRS 169183]) 
Multiscale Thermohydrologic Model 
ANL-EBS-MD-00049 (BSC 2004 [DIRS 169565]) 
Abstraction of Drift Seepage 
MDL-NBS-HS-000019 (BSC 2004 [DIRS 169131]) 
6.2.1.7 Seismicity Associated with Igneous Activity (1.2.03.03.0A) 
FEP Description: Seismicity associated with future igneous activity in the Yucca 
Mountain region may affect repository performance. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: Seismicity associated with igneous activity was either specifically 
considered, or was considered within the background evaluation of 
ground motion by expert elicitation teams in developing 
probabilistic ground motion hazards. Because the effects are 
included in the hazard curves used to evaluate seismic-induced 
damage, igneous related seismicity is implicitly included in the 
TSPA-LA. Analysis model reports supporting the Screening 

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ANL-WIS-MD-000005 REV 02 6-36 November 2004 
Decision contain tables of included FEPs with pointers to more 
detailed background information on this FEP (BSC 2004 
[DIRS 170027], Table 6.4-2; BSC 2004 [DIRS 166107], 
Table 6-50). 
The technical basis for inclusion of this FEP is that ground motion associated with igneous 
activity has the potential to disrupt the integrity of the EBS and waste package components. 
Repeated vibration of a container and/or container impact with other repository elements could 
potentially cause the container to be damaged (See FEP 1.2.03.02.0A). These events could lead 
to decreased performance and to radionuclide release. However, as will be discussed below, all 
seismic inputs developed to support postclosure seismic analyses account for the igneous 
component of the seismic hazard during the occurrence of a seismic event. 
At Yucca Mountain, earthquakes associated with igneous activity would be related to basaltic 
intrusion and volcanism. Volcanic eruption is commonly preceded and accompanied by swarms 
of earthquakes that indicate progressive rock-strength failure as magma migrates to the earths 
surface, as reported in a study by Smith et al. (1998 [DIRS 118967], p. 158). That study 
specifically mentions that magma intrusion into the seismogenic crust tends to supplant large 
tectonic earthquakes with swarms of low to moderate magnitude earthquakes. Smith et al. (1998 
[DIRS 118967], Table 1) summarize published accounts of observed seismicity that is clearly 
associated with dike intrusion and indicate that dike-induced earthquakes in volcanic rift zones 
worldwide have a mean maximum magnitude of 3.8  0.8, and are generally less than 
magnitude 5. In the analysis report, Characterize Eruptive Processes at Yucca Mountain Nevada 
(BSC 2004 [DIRS 169980], Section 6.3.1.3), the dike length distribution used by the PVHA 
experts is used as a proxy for surface-fault lengths to calculate maximum magnitudes of 
dike-induced earthquakes. Calculations indicated maximum magnitudes of 4.8, 5.8, and 6.2. An 
analysis of the ground motion associated with the range of maximum magnitude earthquakes 
assessed for basalt dike intrusions is presented in Development of Earthquake Ground Motion 
Input for Preclosure Seismic Design and Postclosure Performance Assessment of a Geologic 
Repository at Yucca Mountain, Nevada (BSC 2004 [DIRS 170027], Section 6.5). 
As stated in Characterize Framework for Seismicity and Structural Deformation at Yucca 
Mountain, Nevada (BSC 2004 [DIRS 168030], Section 6.4.4), the PSHA was computed by 
integrating recurrence curves for earthquakes of Mw 5.0 and greater. It is established practice 
that smaller earthquakes produce no damage to well-engineered structures. Seismicity related to 
volcanic processes, particularly basaltic volcanoes and dike injection, was explicitly modeled in 
the volcanic source zones by two of the six expert teams working on the PSHA (as summarized 
in BSC 2004 [DIRS 168030], Table 5). The maximum magnitudes assigned by the two expert 
teams put greater weight on magnitudes from 5.4 and 5.8, which is consistent with the range of 
maximum earthquake magnitudes calculated based on dike length distributions (BSC 2004 
[DIRS 169980], Section 6.3.1.3). The other PSHA expert teams presumed that the low 
magnitude and frequency of igneous-related seismicity was accounted for by the areal source 
zone evaluation used for the PSHA. 
Seismicity associated with igneous activity is implicitly included in TSPA because seismicity 
associated with igneous activity is included in the PSHA results (through volcanic source zones 
or areal source zones). Consequently, all seismic inputs developed to support postclosure 

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ANL-WIS-MD-000005 REV 02 6-37 November 2004 
seismic analyses account for the igneous component of the seismic hazard during the occurrence 
of a seismic event. It is therefore inappropriate to represent igneous-related seismicity in the 
TSPA-LA by a parameter or submodel independent of the PSHA results. The range in 
magnitude of dike-induced earthquakes considered does not represent a separate, credible 
damage mechanism that could contribute to enhanced failure potential of intact waste packages 
during the 10,000-year performance period. Waste package damage due to a related igneous 
intrusion is addressed separately in FEP 1.2.04.04.0A (Igneous intrusion interacts with EBS 
components). 
Supporting Reports: Characterize Eruptive Processes at Yucca Mountain, Nevada 
ANL-MGR-GS-000002 (BSC 2004 [DIRS 169980]) 
Characterize Framework for Seismicity and Structural 
Deformation at Yucca Mountain, Nevada 
ANL-CRW-GS-000003 (BSC 2004 [DIRS 168030]) 
Development of Earthquake Ground Motion Input for Preclosure 
Seismic Design and Postclosure Performance Assessment of a 
Geologic Repository at Yucca Mountain, Nevada 
MDL-MGR-GS-000003 (BSC 2004 [DIRS 170027]) 
6.2.1.8 Hydrologic Response to Seismic Activity (1.2.10.01.0A) 
FEP Description: Seismic activity, associated with fault movement, may create new 
or enhanced flow pathways and/or connections between 
stratigraphic units, or it may change the stress (and therefore fluid 
pressure) within the rock. These responses have the potential to 
significantly change the surface and groundwater flow directions, 
water level, water chemistry, and temperature. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: This FEP specifically addresses the effects of seismic activity on 
UZ and SZ flow and transport at the mountain scale, and addresses 
the possibility of a water-table rise in response to seismic activity 
(e.g., seismic pumping). However, the changes in flow properties 
are insignificant at the mountain scale and the potential for a rise in 
water level is both transient in nature and insignificant with regard 
to reaching the repository level. The FEP is therefore, excluded. 
The technical basis for exclusion of this FEP is discussed in the following paragraphs. It is 
recognized that seismic activity can cause changes in rock stresses. The change in the state of 
stress, in turn, has the potential to affect the groundwater flow and the transport properties of the 
UZ and/or SZ, and possibly flow through the emplacement drifts. Changes in flow through the 
drifts have the potential to increase degradation of EBS components and waste packages, leading 
to a release of radionuclides. Flow change is addressed separately in FEP 1.2.03.02.0D 
(Seismic-induced drift collapse alters in-drift thermal-hydrology) in Section 6.2.1.6. 

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The effects of seismic activity in the UZ could result in changes to the hydrologic characteristics 
of fractures, as expressed through the UZ model parameter of fracture aperture. The effects of 
fracture systems changes due to seismic activity on mountain-scale flow and radionuclide 
transport have been investigated using a sensitivity approach (BSC 2004 [DIRS 170012], 
Appendix D). The effects of fracture aperture changes are examined because several fracture 
properties (permeability, capillary pressure, and porosity) are functions of fracture aperture. The 
results indicate that changes in fracture aperture confined to fault zones show virtually no effect 
on transport behavior in the UZ and increased fracture aperture applied over the entire UZ 
domain results in effects that are no more significant than other uncertainties related to 
infiltration (BSC 2004 [DIRS 170012], Appendix D). 
Earthquakes can cause changes in groundwater levels, sometimes at distances far removed from 
the epicenter. Gauthier et al. (1996 [DIRS 100447], p. 164) evaluated water level responses to 
normal, listric, and strike-slip faulting. This sensitivity study indicated that, for Yucca Mountain, 
the greatest strain-induced changes in water-table elevation (approximately 50 m) occur with 
strike-slip faults. Such changes, if permanent, would have the potential to alter 
groundwater-flow directions, but the fluctuation is transient. The mechanisms for affecting 
water chemistry and temperature are undefined, but they are presumed linked to a change in 
groundwater levels and associated changes in geochemical conditions. However, as noted, 
water-level changes usually are transient, although the reversion to pre-earthquake levels may 
require several months. 
Three seismic events in 1992 provide estimates of water level fluctuations occurring in response 
to earthquakes. These include the magnitude 7.5 earthquake at Landers, California, occurring on 
June 28th, 1992, followed a few hours later by the magnitude 6.6 earthquake at Big Bear Lake, 
California (OBrien 1993 [DIRS 101276]). These earthquakes were regional, located about 
293 km and 296 km, respectively, away from Yucca Mountain. A third magnitude 5.6 
earthquake occurred June 29, 1992, about 23 km from Yucca Mountain at Little Skull Mountain. 
The 1992 data from the groundwater monitoring wells are listed in DTN: GS930108312312.003 
[DIRS 171974] documenting the earthquake-induced fluctuations in water level. The Landers 
earthquake caused about a 90 cm water level fluctuation at well USW H-5. The following Big 
Bear Lake earthquake caused a 20 cm water level fluctuation. The response of well USW H-3 to 
the Landers earthquake involved a brief water level spike followed by 20 cm decrease, returning 
to near normal levels within several hours. The response of wells USW H-5 and USW H-6 to 
the magnitude 5.6 Little Skull Mountain earthquake was 40 and 20 cm, respectively. The water 
level decreased about 50 cm at well UE-25 P#1 over three days following the earthquake. 
Based on the data in DTN: GS930108312312.003, these earthquakes produced mostly 
short-term water level fluctuations on the order of tens of centimeters. Many other wells showed 
no response or smaller fluctuations on the order of hours (OBrien 1993 [DIRS 101276]). For 
perspective it is noted that the repository would be located approximately 300 m above the 
current water table. This suggests that earthquake-induced water level fluctuations can be 
considered negligible relative to the scale of the total system performance assessment. 
Perspectives on seismic pumping and water-level changes are discussed in the Final 
Environmental Impact Statement (DOE 2002 [DIRS 155970], p. 3-59), which cites the work by a 

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panel of the National Research Council (1992 [DIRS 105162]). The panel reviewed an 
alternative conceptual model that predicted large changes in water levels and concluded that it 
was infeasible. The panel went on to state that seismic pumping would, at most elevate the water 
levels a few tens of meters. 
By way of corroboration, Gauthier et al. (1996 [DIRS 100447], pp. 163 to 164) analyzed the 
potential effects of seismic activity on contaminant transport in the SZ due to changes in 
water-table elevation. Their simulations for TSPA-VA of the timing, amplitude, and duration of 
water-table rise indicated a maximum rise of 50 m within an hour of a simulated seismic event. 
The simulated system returned to steady-state conditions within six months. Gauthier et al. 
(1996 [DIRS 100447], pp. 163 to 164) conclude that: 
In general, seismically induced water-table excursions caused by poroelastic 
coupling would not influence the models presently being used to determine 
long-term performance of a repository at Yucca Mountain; therefore, we excluded 
them from the total-system simulations. 
Given the changes in water levels following discrete seismic events as reported by the U.S. 
Geological Survey (OBrien 1993 [DIRS 101276]), it would appear that the conclusion by 
Gauthier et al. (1996 [DIRS 100447]) remains valid. 
Sensitivity modeling indicates that changes to faults and fracture properties due to changes in 
stress and strain are inconsequential to groundwater flow at the mountain scale. Therefore, the 
FEP is excluded from the TSPA-LA based on low consequence. Additionally, because 
water-table changes caused by seismic activity do not reach the repository level and are transient, 
groundwater flow and radionuclide transport are not significantly affected. The hydrologic 
response to seismic activity, therefore, does not provide a mechanism to significantly affect dose. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.1.9 Seismic Activity Changes Porosity and Permeability of Rock (2.2.06.01.0A) 
FEP Description: Seismic activity (fault displacement or vibratory ground motion) 
has a potential to change rock stresses and result in strains that 
affect flow properties in rock outside the excavation-disturbed 
zone. It could result in strains that alter the permeability in the 
rock matrix. These effects may decrease the transport times for 
potentially released radionuclides. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: Future seismic activity could redistribute strain within the system. 
Redistribution of strain could increase the aperture of some 
existing fractures, open new fractures, or close some existing 
fractures, as presumed by Gauthier et al. (1996 [DIRS 100447], 
p. 163). Given the extensive fracture network at Yucca Mountain 

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and the low rates of seismic/tectonic activity, the rock matrix is 
largely unaffected by strain redistribution. 
This FEP, 2.2.06.01.0A (Seismic activity changes porosity and permeability of rock), and two 
closely related FEPs, 2.2.06.02.0A (Seismic activity changes porosity and permeability of faults) 
and 2.2.06.02.0B (Seismic activity changes porosity and permeability of fractures), are all 
excluded based on low consequence. For the FEPs that address faults and fractures, there are 
analyses that are directly applicable, but for this FEP that concerns the rock matrix, the technical 
basis for exclusion relies in part on an approximation developed for a thermal modeling report 
(BSC 2004 [DIRS 169864]) and in part, on a reasoned logic argument, rather than on specific 
analyses. 
The effects of stress changes on flow in the UZ have been investigated by BSC (2004 
[DIRS 169864]). In this model, the effects of thermal stress are evaluated in terms of changes to 
rock fracture properties, but not rock matrix. This modeling approach is based on the 
approximation that the effects of changes to the rock matrix porosity and permeability caused by 
changes in rock stress are negligible compared with changes to the fracture porosity and 
permeability (BSC 2004 [DIRS 170012], Section 6.7.5). The basis for this approximation is that 
the fracture aperture is sensitive to mechanical strain due to the small porosity of the fracture 
continuum. The matrix, on the other hand, has much greater porosity than the fractures in 
general, and its properties are not expected to be as sensitive to mechanical strain. This 
approximation is reasonable given the fact that fracture porosity is much less than matrix 
porosity at Yucca Mountain. This insensitivity to mechanical strain should be true for other 
sources of mechanical stress, such as seismic activity. In addition, at the scale of the 
emplacement drifts, the hydrological system is much more affected by the fracture network 
rather than the fairly impermeable matrix. Therefore, changes to the rock matrix characteristics 
due to seismic activity are excluded from TSPA-LA on the basis of low consequence. 
This reasoned argument relies on the discussion in FEP 1.2.01.01.08 (Tectonic 
activity-large-scale). The tectonic setting at Yucca Mountain is extensional, the strain rates are 
low and there is an extensive fracture network in the rock mass. Moreover, it is well known that 
seismic activity can cause movement along fractures in the rock mass. Given the extensive 
fracture network in the rock mass, and the relatively high strength of the matrix material, it is 
expected that the strain introduced by seismic activity will be accommodated by deformation of, 
and slip along fractures. In addition, damage of the matrix material due to seismic loading would 
be manifest in the form of inter-lithophysal tensile fractures that coalesce to form observable 
shear fractures with offset. The exposed lithophysal rocks in the Exploratory Studies Facility 
and the Enhanced Characterization of the Repository Block (ECRB) Cross-Drift; however, show 
no fracturing of this type. Observed fracturing is consistent with the typical cooling-fracture 
related history. Thus, the rocks provide evidence that the matrix material is largely unaffected 
by redistribution of strain introduced by seismic activity. As discussed in FEP 2.2.06.02.0B, the 
results of the PSHA are used to infer that the reactivation of existing fractures is a more likely 
event than the development of new fractures given current geologic conditions and the existing 
stress field. 
Some faults at Yucca Mountain have a strike-slip component of movement and if the fault plane 
is curved or irregular, local areas of compression can be created, even though the overall setting 

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is extensional. The most likely response of the rock mass to these local compressional 
conditions will be the closing of existing fractures, but in certain cases some strain could be 
transferred to the rock matrix causing a local decrease in porosity and permeability. These 
changes, if they occur, would be confined to the fault zones so their impact on flow and transport 
at the mountain scale would be negligible. Therefore, this FEP is excluded based on low 
consequence. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.1.10 Seismic Activity Changes Porosity and Permeability of Faults (2.2.06.02.0A) 
FEP Description: Seismic activity (fault displacement or vibratory ground motion) 
has a potential to produce jointed-rock motion and change stress 
and strains that alter the permeability along faults. This could 
result in reactivation of pre-existing faults or generation of 
significant new faults, which could significantly change the flow 
and transport paths, alter or short-circuit the flow paths and flow 
distributions close to the repository, and/or create new pathways 
through the repository. These effects may decrease the transport 
times for potentially released radionuclides. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: Future seismic activity could redistribute strain within the system. 
Redistribution of strain could open new fractures and close some 
existing fractures, as presumed by Gauthier et al. (1996 
[DIRS 100447], p. 163). It is likely that much of this redistribution 
would occur within the fault zones. 
The technical basis for exclusion of this FEP includes a sensitivity analysis of changes to fracture 
apertures in fault zones in the UZ. As discussed in the following paragraphs, this study 
demonstrated that the consequence of this FEP in the UZ would be negligible and no more 
significant that other uncertainties related to infiltration in the UZ. Furthermore, regardless of the 
strain distribution, the net effect of seismic activity in the SZ is the temporary rise and/or decline in 
water levels associated with seismic events as addressed in FEP 1.2.10.01.0A (Hydrologic 
response to seismic activity). That FEP was excluded based on low consequence of a temporary 
water level rise (or decline) on the order of a few tens of meters. 
Relationships between Faults and FracturesFaulting and fracturing have been studied in 
considerable detail at Yucca Mountain. Two conclusions from a study by Sweetkind et al. (1997 
[DIRS 100183], pp. 67 to 71) suggest that faulting and fracturing are spatially related. First, 
spatial relationships based on the results of underground mapping of faults have led to the 
definition and description of zones of influence around faults based on the observation that 
fracture frequency generally increases as faults are approached. Mapping results show that 
widths of zones of influence are in general quite narrow, ranging from less than 1 m to about 7 m 
from the faults. The second conclusion is that the width of the zone of influence in the 

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immediate vicinity of a fault generally correlates with the amount of cumulative fault offset. 
Therefore, faults having the largest potential future displacement are the most likely to influence 
the repository block. Faults having tens of meters of cumulative offset (e.g., faults at 
Exploratory Studies Facility Stations 11+20, 67+88, and 70+58) have zones of influence that can 
range up to 10 m wide. Intrablock faults having very small amounts of cumulative offset (1 m to 
5 m) have zones of influence that are 1 to 2 m wide. 
The presence of gouge and brecciated zones only in close proximity to fault planes suggests that 
much of the strain will be mechanically dissipated within or near the fault planes. For instance, 
in the Solitario Canyon fault zone in the ECRB Cross-Drift, the total displacement is 
approximately 260 m, but the gouge and brecciated zones are limited to less than 20 m from the 
main fault trace (Mongano et al. 1999 [DIRS 149850], pp. 59 to 65). As exposed during as-built 
mapping, the clast-supported breccia is observed between Station 25+80 and 25+99.15. 
Similarly, the Dune Wash fault exposed in the Exploratory Studies Facility exhibits a cumulative 
offset of 65 m, but the zone of increased fracture frequency in the vicinity of the fault is only 6 to 
7 m wide (Sweetkind et al. 1997 [DIRS 100183], Table 21). A third example is the Sundance 
fault in the ECRB Cross Drift. The Sundance fault has a presumed, though indeterminate, 
displacement of several meters. However, the footwall rock is intact at a distance of only 10 cm 
from the fault plane. The hanging wall of the Sundance fault is slightly more fractured, having 
an intensely fractured zone about 1-m thick (Mongano et al. 1999 [DIRS 149850], pp. 52 to 54). 
Potential for the Development of New FaultsAnother aspect of faulting that could be important 
to repository performance is the formation of new faults. Section 6.2.1.2 and Table 6-1 provide a 
discussion of probabilistic fault displacements. With regard to the formation of new faults, the 
PSHA (CRWMS M&O 1998 [DIRS 103731], p. 8-7; DTN: MO0401MWDRPSHA.000 
[DIRS 166962], referring to intact rock at Points 7d and 8d) indicates that mean displacements in 
the intact rock are less than 0.1 cm for a 10-8 annual-exceedance probability (see Assumption 5.1 
in Section 5). The development of significant new faults and fractures is inferred from the 
PSHA to be unlikely and is, therefore, not further considered within this FEP. 
Potential for the Reactivation of Existing FaultsMany of the existing faults at Yucca Mountain 
are favorably oriented for movement in the current stress field and any large potential future 
displacements are expected to occur along the existing block-bounding faults. The largest mean 
predicted displacement at 10-8 annual exceedance probability is associated with the Solitario 
Canyon fault and the mean displacement is estimated to be on the order of 10 m. The median 
predicted displacement is calculated to be on the order of only a few meters. (See 
FEP 1.2.02.03.0A, Fault displacement damages EBS components, for a table of estimated 
displacements). The effects of this range of displacements are addressed by the range of aperture 
conditions assessed in a sensitivity study, as discussed in the following paragraphs. 
Analysis of Fracture Aperture Changes in Fault Zones in the UZThe effects of changes to 
fracture systems in the UZ fault zones have been investigated (BSC 2004 [DIRS 170012], 
Appendix D). A sensitivity study was performed with the nominal UZ three-dimensional flow 
model using several conservative approaches that together provided bounding cases for 
determining whether changes in fractures will significantly impact repository performance. The 
analysis was performed using a dual-permeability active-fracture flow model and was based on 

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fracture apertures changes that could result from changes in strain conditions or other factors. 
Given a change in fracture aperture, other fracture hydrologic properties (permeability, capillary 
pressure, and porosity) were estimated using theoretical models (BSC 2004 [DIRS 170012], 
Appendix D). The sensitivity study (BSC 2004 [DIRS 170012], Appendix D) included two 
bounding cases: that changes in fracture properties occur over the entire UZ domain (fault zones 
and fractured rock), or that the effects of fault displacement are limited to fracture-property 
changes in fault zones, which is directly applicable to this FEP. These modeling cases were 
chosen to bound a presumed range of fracture-aperture changes resulting from fault movement. 
No direct observations for Yucca Mountain relate stress caused by fault displacement to strain 
and the resultant changes in fracture aperture (BSC 2004 [DIRS 170012], Appendix D). The 
bounding cases were used to simulate a response beyond that of the expected geologic response. 
The second bounding case (effects of fault displacement limited to fault zones) is important to 
this discussion and is justified based on conclusions by Sweetkind et al. (1997 [DIRS 100183], 
pp. 67 to 71) and field observations by Mongano et al. (1999 [DIRS 149850]), described above. 
A potential conservatism for the sensitivity analysis lies in the estimated fracture aperture for the 
bounding case. A maximum ten-fold increase in fracture aperture is selected as the models 
upper-bound value and was justified in BSC (2004 [DIRS 170012], Appendix D). The 
justification cites distance-strain relationships derived from models for a 1-m displacement along 
a strike-slip fault at Yucca Mountain, and for a 1-m displacement on a theoretical normal fault. 
The changes in fracture apertures for the sensitivity analysis were derived presuming a 10-m 
fault movement along the Solitario Canyon fault and multiplying the strains cited in the 
justification for the 1-m faults. The 10-m displacement corresponds to the projected mean value 
for the Solitario Canyon fault at 10-8 annual frequency (see Assumption 5.1 in Section 5) and 
serves as the basis for FEPs screening. The potential for conservatism is mentioned primarily 
because the presumed 10-m displacement, although a mean value, is greater than the 
probabilistically determined (median and 85th fractile) and observed fault displacements. The 
results of the PSHA (CRWMS M&O 1998 [DIRS 103731], Figure 8-3) indicate that, for the 
Solitario Canyon fault, there is a large uncertainty range in the potential displacements from 3 m 
(the median value) to approximately 9 m (the 85th fractile value) at the 10-8 annual-exceedance 
probability. By contrast, the maximum measured single-event Quaternary displacement 
(i.e., during the past 1.6 million years) on the Solitario Canyon fault is only 1.3 m (Ramelli et al. 
1996 [DIRS 101106], Table 4.7.3). 
The results of the sensitivity study have shown that fracture aperture changes confined to fault 
zones resulted in virtually no effect on transport behavior in the UZ (BSC 2004 [DIRS 170012], 
Appendix D). Because transport is not significantly affected by fracture aperture changes in 
fault zones, changes in the stress state of fractures in faults do not provide a mechanism to 
significantly affect dose. Because dose is not significantly affected, the effects of faults and 
changes on the transport-properties of faults in the UZ are excluded based on low consequence. 
Evaluation of Changes in Fault Zones in the SZThe primary response of regional water levels to 
seismic events, as discussed in FEP 1.2.10.01.0A, is a transient change (increase or decline) in 
the water table. The SZ model (Saturated Zone Flow and Transport Model Abstraction 
(BSC 2004 [DIRS 170042], Section 6.5.2) uses the flowing intervals concept, which is based on 
site data and indicates that only some of the fractures within the saturated zone contribute to the 
flow. Additionally, the SZ model implicitly includes fracture zones (faults) in the nominal case 

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by considering the horizontal anisotropy in permeability located in the fractured volcanic units 
downgradient of the repository with the SZ model producing 200 flow fields. The SZ model 
(BSC 2004 [DIRS 170042], Section 6.5.2) does not explicitly address changes to fracture or fault 
properties due to changes in stress. However, because of the existing uncertainty considerations 
for the flow field and because of the conservative choices for flowing-interval spacing used for 
the analysis, the effect of increasing or decreasing matrix and fracture porosity and permeability, 
and/or the creation of new fractures in the SZ, would be of no significance to flow and transport 
characteristics. Because SZ flow characteristics are not significantly changed, dose is not 
significantly changed and this aspect of the FEP is excluded based on low consequence. 
By way of corroboration, an early analysis of the effect of a fault on flow in the SZ was 
conducted and documented in Chapter 10 of the TSPA-VA (CRWMS M&O 1998 
[DIRS 100369], Section 10.5.3). The analysis suggested that there would be negligible impact 
on performance, even though fault hydraulic conductivities were varied over five orders of 
magnitude for the modeling effort. 
Also, by way of corroboration, Gauthier et al. (1996 [DIRS 100447], pp. 163 to 164) analyzed 
the potential effects of seismic activity on contaminant transport in the SZ due to changes in 
water-table elevation based on TSPA-VA modeling. Their analysis indicates that the greatest 
strain-induced changes in water-table elevation occur with strike-slip faults. Simulations of the 
timing, amplitude, and duration of a water-table rise indicate a maximum rise of 50 m within an 
hour of a simulated event. The simulated system returns to steady-state conditions within six 
months. Gauthier et al. (1996 [DIRS 100447], pp. 163 and 164) concluded that: 
In general, seismically induced water-table excursions caused by poroelastic 
coupling would not influence the models presently being used to determine 
long-term performance of a repository at Yucca Mountain; therefore, we excluded 
them from the total-system simulations. 
Given the response of regional water levels to seismic events, as discussed in FEP 1.2.10.01.0A, 
the conclusion by Gauthier for TSPA-VA still appears valid for the current analysis. 
In summary, effects in the UZ could result in changes to the hydrologic characteristics of 
fractures, as expressed through the parameter of fracture aperture. The effects of changes to 
fracture systems due to geologic effects on mountain-scale flow and radionuclide transport have 
been investigated using a sensitivity approach (BSC 2004 [DIRS 170012], Appendix D). The 
results indicate that changes in fracture aperture confined to fault zones show virtually no effect 
on transport behavior in the UZ, and increased fracture aperture applied over the entire UZ 
domain results in effects that are no more significant than other uncertainties related to 
infiltration (BSC 2004 [DIRS 170012], Appendix D). Effects in the SZ would not impact dose 
and would be transient. Therefore, this FEP is of low consequence and is excluded from the 
TSPA-LA. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 

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6.2.1.11 Seismic Activity Changes Porosity and Permeability of Fractures (2.2.06.02.0B) 
FEP Description: Seismic activity (fault displacement or vibratory ground motion) 
has a potential to change stress and strains that alter the 
permeability along fractures. This could result in reactivation of 
pre-existing fractures or generation of new fractures, which could 
significantly change the flow and transport paths, alter or 
short-circuit the flow paths and flow distributions close to the 
repository, and/or create new pathways through the repository. 
These effects may decrease the transport times for potentially 
released radionuclides. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: The tectonic strain rate controlling the seismic and fault 
displacement events leading to small-scale displacements was 
evaluated as an uncertain parameter in the PSHA, and the 
uncertainty in the tectonic rate is, thereby, reflected in the PSHA 
results (see the FEP 1.2.01.01.0A Tectonic activity-large scale). A 
sensitivity analysis, discussed below, was performed and 
demonstrated that the consequence would be negligible. 
The technical basis for exclusion of this FEP includes a sensitivity analysis of changes to fracture 
apertures applied over the entire UZ domain. As discussed in the following paragraphs, this 
study demonstrated that the consequence of this FEP would be no more significant than other 
uncertainties related to infiltration in the UZ (BSC 2004 [DIRS 170012], Appendix D) and this 
FEP can therefore be excluded. Furthermore, regardless of the strain distribution, the net effect of 
seismic activity in the SZ is the temporary rise and/or decline in water levels associated with 
seismic events as addressed in FEP 1.2.10.01.0A (Hydrologic response to seismic activity). That 
FEP was excluded based on low consequence of a temporary water level rise (or decline) on the 
order of a few tens of meters. 
Potential for Fracture Reactivation or the Development of New FracturesAlthough an analysis 
of the reactivation of existing fractures, or the creation of new fractures, was not the primary 
purpose of the study, the PSHA (CRWMS M&O 1998 [DIRS 103731], p. 8-7) does examine the 
probability of movement along existing fractures, both with displacement and with no 
measurable cumulative displacement (reactivation), and the development of small-scale 
displacements in the intact rock (new fractures). The results are used to infer that the 
reactivation of existing fractures is a more likely event than the development of new fractures 
given current geologic conditions and the existing stress field. This inference concerning small 
displacement probabilities relates in part, on the definition of fractures. 
According to the NRC (1999 [DIRS 135621], p. 55), fractures are characterized by motion 
perpendicular to the fracture walls (extension fractures), by motion parallel to the fracture walls 
(shear fractures), or by very small displacement normal to their surfaces and little or no 
displacement parallel to their surfaces (joints). The range of displacements extends upward to 
amplitudes that characterize faults, which typically originate as shear fractures capable of 

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fracturing across discontinuities. According to Bates and Jackson (1987 [DIRS 164050], p. 257), 
the term fracture is a general term for any break in a rock, whether or not it causes 
displacement, due to mechanical failure by stress. Fracture includes cracks, joints, and faults. 
Consequently, fractures involve a range from small cracks with no displacement, up to and 
including, features with considerable displacement that are typically called faults. 
As explained in FEP 1.2.02.03.0A, the PSHA (CRWMS M&O 1998 [DIRS 103731]) examined 
displacements at specific points along faults, including hypothetical points representing existing 
small faults, shears, and fractures (Points 7 and 8). Referring to intact rock, or condition (d) at 
hypothetical Points 7 and 8 within the repository block, the PSHA (CRWMS M&O 1998 
[DIRS 103731], p. 8-7) indicates that the probability of a movement (i.e., minimal displacement 
of less than 0.1 cm) developing in the intact rock (a new fracture) has a less than 10-8 
annual-exceedance probability (see Assumption 5.1 in Section 5). The PSHA (CRWMS M&O 
1998 [DIRS 103731], Figures 8-10 and 8-13 for points 7c and 8c) also indicates that fractures 
within the current repository area having no measured displacements can be expected to 
experience on the order of 0.1 to 1 cm of displacement (reactivation) at the 10-8 
annual-exceedance probability. The PSHA indicates that at the same 10-8 annual-exceedance 
probability, existing fractures with 10 cm of offset, small hypothetical faults with 2 m of offset, 
intra-block faults, and block-bounding faults have progressively larger amounts of potential 
offset (See Table 6-1). By inference, this means that the PSHA anticipates that the vast majority, 
if not all, future strain would be accommodated on existing faults and fractures with the largest 
structures (block-bounding faults) experiencing the largest changes. Also by inference from the 
PSHA, the development of new fractures due to seismic activity and associated fault 
displacement is inferred to be both of low probability and of low consequence given the existing 
extensive fracture network. In other words, given the current network of small to large 
displacement fractures with varying apertures and other characteristics, the very unlikely 
development of a few more very small displacement (less than 0.1 cm) fractures in presently 
intact rock is not going to noticeably affect flow or transport. The interpretation from the PSHA 
that movement along existing fractures is more likely than the development of new fractures is 
directly supported by field observations and consideration of the geologic history of Yucca 
Mountain. 
Strain is more likely to affect existing features, rather than to create new fractures. Field 
observations indicate that the rock at Yucca Mountain is highly fractured and that existing 
fractures and joints have been subject to reactivation (BSC 2004 [DIRS 166107]). Evidence for 
reactivation of joints includes the presence of thin breccia zones along cooling joints and 
observable slip lineations along joint surfaces (Sweetkind et al. 1996 [DIRS 106957]). Cooling 
joints, formed originally as tensional openings, have only normal displacement, not shear. 
However, thin selvages of tectonic breccia are locally present along the trace of cooling joints, 
indicating later slip. Based on these field observations, the fracture network appears to act as a 
significant pre-existing weakness in the rock mass that can accommodate extensional strain 
through distributed slip along many reactivated joints. Coupled with the results of the PSHA for 
movement in the intact rock, it appears that changes in strain are more likely to be 
accommodated along existing fractures, rather than the initiation new fractures. Therefore, 
consideration of new fractures is excluded for this FEP. 

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Analysis of Changes to Fractures in the UZThe effects of changes to fracture systems in the UZ 
and to fault zones in the UZ have been investigated using a sensitivity approach (Fault 
Displacement Effects on Transport in the Unsaturated BSC (2004 [DIRS 170012], Appendix D). 
The sensitivity study was performed with the nominal UZ three-dimensional flow model using 
several conservative approaches that, together, provide bounding cases for determining whether 
changes in fractures would significantly impact repository performance. The analysis was 
performed using a dual-permeability active-fracture flow model and was based on the fracture 
aperture changes resulting from changes in strain conditions or other factors. Given a change in 
fracture aperture, other fracture hydrologic properties (permeability, capillary pressure, and 
porosity) were estimated using theoretical models. 
The sensitivity study (BSC 2004 [DIRS 170012], Appendix D) included two bounding cases: 
(1) that changes in fracture properties occur over the entire UZ domain (fault zones and fractured 
rock), which is directly applicable to this FEP; or (2) that the effects of fault displacement are 
limited to fracture-property changes in fault zones (See FEP 2.2.06.02.0A Seismic activity 
changes porosity and permeability of faults). These were modeling cases chosen to bound a 
presumed range of fracture-aperture changes resulting from seismic activity and fault movement. 
There are no direct observations for Yucca Mountain that relate stress caused by fault 
displacement to strain and resultant changes in fracture aperture. The bounding cases were used 
to simulate a response beyond that of the expected geologic response. 
The results of the sensitivity study (BSC 2004 [DIRS 170012], Appendix D) have shown that 
changes in fracture aperture confined to fault zones resulted in virtually no effect on transport 
behavior in the UZ and that increased fracture aperture applied over the entire UZ domain results 
in effects that are no more significant than other uncertainties related to infiltration (BSC 2004 
[DIRS 170012], Appendix D). Changes in fracture aperture are inferred to be equivalent to 
reactivation of existing fractures for purposes of this FEP. 
Because neither flow nor transport is significantly affected by reactivation of fractures that 
causes a change in fracture aperture, dose is not significantly affected. Therefore, for the UZ, 
this FEP is excluded based on low consequence. 
Evaluation of Changes in Fractures in the SZThe primary response of regional water levels to 
seismic events, as discussed in FEP 1.2.10.01.0A, is a transient change (increase or decline) in 
the water table. The SZ model (Saturated Zone Flow and Transport Model Abstraction 
(BSC 2004 [DIRS 170042], Section 6.5.2) uses the flowing intervals concept. The flowing 
interval concept, based on site data, indicates that only some of the fractures within the saturated 
zone contribute to the flow. Additionally, the SZ model implicitly includes fracture zones in the 
nominal case by considering the horizontal anisotropy in permeability located in the fractured 
volcanic units downgradient of the repository, with the SZ model producing 200 flow fields. 
The SZ model (BSC 2004 [DIRS 170042], Section 6.5.2) does not explicitly address changes to 
fracture properties due to changes in stress. However, because of the existing uncertainty 
considerations for the flow field, and because of the conservative choices for flowing-interval 
spacing used for the analysis, the effect of increasing or decreasing matrix and fracture porosity 
and permeability, and/or the creation of new fractures in the SZ would be of no significance to 
flow and transport characteristics. Because SZ flow characteristics are not significantly changed, 

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dose is not significantly changed and this aspect of the FEP is excluded based on low 
consequence. 
By way of corroboration, an early analysis of the effect of a fault on flow in the SZ was 
conducted and documented in Chapter 10 of the TSPA-VA (CRWMS M&O 1998 
[DIRS 100369], Section 10.5.3). The analysis suggested that there would be negligible impact 
on performance, even though fault (fracture) hydraulic conductivities were varied over five 
orders of magnitude for the modeling effort. 
Also, by way of corroboration, Gauthier et al. (1996 [DIRS 100447], pp. 163 to 164) analyzed 
the potential effects of seismic activity on contaminant transport in the SZ due to changes in 
water-table elevation based on TSPA-VA modeling. Their analysis indicates that the greatest 
strain-induced changes in water table elevation occur with strike-slip faults. Simulations of the 
timing, amplitude, and duration of a water-table rise indicate a maximum rise of 50 m within an 
hour of a simulated event. The simulated system returns to steady-state conditions within six 
months. Gauthier et al. (1996 [DIRS 100447], pp. 163 and 164) concluded that: 
In general, seismically induced water-table excursions caused by poroelastic 
coupling would not influence the models presently being used to determine 
long-term performance of a repository at Yucca Mountain; therefore, we excluded 
them from the total-system simulations. 
Given the response of regional water levels to seismic events, as discussed in FEP 1.2.10.01.0A, 
the conclusion by Gauthier for TSPA-VA still appears valid for the current analysis. 
In summary, effects in the UZ could result in changes to the hydrologic characteristics of 
fractures, as expressed through the parameter of fracture aperture. The effects of changes to 
fracture systems due to geologic effects on mountain-scale flow and radionuclide transport have 
been investigated using a sensitivity approach (BSC 2004 [DIRS 170012], Appendix D). The 
results indicate that changes in fracture aperture confined to fault zones show virtually no effect 
on transport behavior in the UZ. Furthermore, increased fracture aperture applied over the entire 
UZ domain results in effects that are no more significant than other uncertainties related to 
infiltration (BSC 2004 [DIRS 170012], Appendix D). Effects in the SZ would not impact dose 
and would be transient. Therefore, this FEP is of low consequence and is excluded from the 
TSPA-LA. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.1.12 Seismic Activity Alters Perched Water Zones (2.2.06.03.0A) 
FEP Description: Strain caused by stress changes from tectonic or seismic events 
could alter the rock permeabilities that allow formation and 
persistence of perched-water zones. 

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Screening Decision: Excluded - Low Consequence. 
Screening Argument: Based on a volumetric argument, the release of perched water 
would have no significant consequence on exposure or release of 
radionuclides to the accessible environment and therefore this FEP 
is excluded on the basis of low consequence. 
A change in stress due to seismic activity has the potential to result in strains that affect 
groundwater flow and transport properties, leading to increased or decreased dose. It 
appears possible that a change in stress could adequately seal a zone so that perched water 
develops. Hypothetically, such changes have the potential to result in a relatively sharp pulse of 
radionuclides if radionuclide-containing perched water is allowed to drain. This FEP is analyzed 
using the volume of known perched water bodies below the repository and comparing this 
volume to the volume of the water flux entering the repository footprint. Perched water zones 
below the elevation of the repository have been found in site characterization boreholes 
(BSC 2004 [DIRS 170012], Section 6.7.8). 
The UZ flow model shows that the volume of perched water in the high-permeability fracture 
domain below the repository only ranges from about 466 m3 to 1,190 m3 (BSC 2004 
[DIRS 170012], Section 6.8.8). This smaller volume in the high permeability fractures may be 
compared with the water flux entering the repository footprint (i.e., the average infiltration rate 
times the area of the repository footprint). The annual infiltration volume ranges from 2,000 to 
192,000 m3/yr. As shown in Appendix A (BSC 2004 [DIRS 170012]), the perched water volume 
is seen to represent about 0.006 to 0.2 years of water flux. Thus, the perched water volume in 
high-permeability fractures that is subject to rapid drainage is small compared to the water flux 
through the repository horizon for one year. Even if released instantaneously by a seismic event, 
the release of perched water would have no significant consequence on exposure or release of 
radionuclides to the accessible environment. Therefore, this FEP is excluded from the 
TSPA-LA based on low consequence. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.2 Igneous-Related FEPs 
The following subsections provide the screening decision and technical basis for inclusion and 
exclusion of the following igneous-related FEPs. 
1.2.04.02.0A Igneous activity changes rock properties (Section 6.2.2.1) 
1.2.04.03.0A Igneous intrusion into repository (Section 6.2.2.2) 
1.2.04.04.0A Igneous intrusion interacts with EBS components (Section 6.2.2.3) 
1.2.04.04.0B Chemical effects of magma and magmatic volatiles (Section 6.2.2.4) 
1.2.04.05.0A Magma or pyroclastic base surge transports waste (Section 6.2.2.5) 
1.2.04.06.0A Eruptive conduit to surface intersects repository (Section 6.2.2.6) 
1.2.04.07.0A Ashfall (Section 6.2.2.7) 
1.2.04.07.0C Ash redistribution via soil and sediment transport (Section 6.2.2.8) 
1.2.10.02.0A Hydrologic response to igneous activity (Section 6.2.2.9) 

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6.2.2.1 Igneous Activity Changes Rock Properties (1.2.04.02.0A) 
FEP Description: Igneous activity near the underground facility may cause extreme 
changes in rock stress and the thermal regime, and may lead to 
rock deformation, including activation, creation, and sealing of 
faults and fractures. This may cause changes in the rock 
hydrologic and mineralogic properties. Permeabilities of dikes and 
sills and the heated regions immediately around them can differ 
from those of country rock. Mineral alterations can also change 
the chemical response of the host rock to contaminants. 
Screening Decision: Excluded - Low Consequence 
Screening Argument: With regard to extreme changes in hydrologic properties, sills and 
dikes initially intrude into the country rock as molten material and 
then cool. Cooling joints are formed and resulting permeabilities 
may be greater than, equivalent to, or less than the surrounding 
country rock. However, the scale of these effects is limited to a 
few meters around the dike and changes in properties are therefore 
of low consequence. 
The technical basis for exclusion of this FEP relies in part on studies of analogue sites in the 
Yucca Mountain Region. In addition, analyses of igneous activity and analyses of the effects of 
fault displacement on the UZ are utilized. This FEP is concerned with post-intrusion effects on 
rock properties; impacts from the igneous intrusion process itself are addressed in 
FEP 1.2.04.03.0A. 
Limited Zone of Influence Around Igneous Intrusions -- An appropriate analogue for 
understanding the components of a potential future igneous event at Yucca Mountain is the 
Paiute Ridge intrusive/extrusive center (Byers and Barnes 1967 [DIRS 101859]) on the 
northeastern margin of the Nevada Test Site. The Paiute Ridge center is a small-volume 
Miocene volcanic center comparable in volume and composition to Quaternary volcanoes near 
Yucca Mountain (BSC 2004 [DIRS 169989], Section 6.3.2.1). Paleomagnetic, geochronologic, 
and geochemical data indicate that the entire intrusive/extrusive complex formed during a brief 
magmatic pulse and, thus, represents a single volcanic event. The vents and associated dike 
system formed within a north-northwest-trending extensional graben and there are excellent 
exposures at a variety of system depths, including remnants of surface lava flows, volcanic 
conduits, and dikes and sills intruded into tuff country rock at depths of up to 300 m. There is 
evidence of shallow structural control of dike emplacement at Paiute Ridge, including dike 
emplacement along fault planes (Byers and Barnes 1967 [DIRS 101859]). Dike lengths at Paiute 
Ridge range from less than 1 km to 5 km, which is comparable to the range estimated for 
post-Miocene volcanism near Yucca Mountain. 

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Carter Krogh and Valentine (1996 [DIRS 160928], pp. 7 and 8) described the margins of the 
Paiute Ridge (PR) dike complex and the interaction of dikes and faults. The description is as 
follows: 
PR dike contains ubiquitous near-vertical joints that result in a pervasive platy 
texture with plates parallel to the dike-host contact. Conversely, with the 
exception of local cooling joints in fused wall rock (extending 10-20 cm into the 
wall rock, perpendicular to the dike margin), joints are never visible in the host 
rock along the length of the dike. The contact between basalt and the tuff host 
rock is consistently smooth and shows no brecciation. Along strike at this 
contact, the tuff host rock is fused or welded to varying degrees: in places the tuff 
is completely welded and forms black vitrophyre that grades rapidly away from 
the contact, over a distance of ca 20-100 cm, into nonwelded tuff that is 
apparently unaffected by the dike. In other places the tuff is only partly welded at 
the contact and black fiamme are elongated parallel to the contact. We infer that 
this contact welding is the combined result of heat from the dike and 
compressive stress exerted by the flowing magma on the wall rocks. Welded host 
rock commonly contains vesicles that are elongated vertically and parallel to the 
margin. In some places, welded tuff coats the basalt and displays rills or elongate 
smooth ridges (flutes). Most rills plunge nearly vertically, however, a 
sub-horizontal rill is present in the central part of the dike. At the dike tip, 
exposed at Slanted Buttes, scoria patches crop out near the dike-host contact. 
The two eastern dikes, M and E  show geometries and textures similar to those 
of PR; however, M dike is much shorter and does not feed a sill, and E dike was 
emplaced closest to the paleosurface and feeds two sills. M dike  visibly 
occupies a normal fault, oriented N40 W, 61 E,  Its host rocks are only 
Tertiary tuffs, which show no brecciation or jointing near the dike contact  
Texture within the dike is characterized by a vertical platy fabric that parallels the 
dike margins. E dike is the eastern-most dike studied within the graben. Near the 
neck, the dike visibly occupies a NNW-trending, steeply E-dipping normal fault 
that displaces bedded tuffs 3.5 m and does not cut the dike The texture of 
E dike is characterized by the pervasive vertical platy fabric common to M and 
PR dikes. Adjacent host tuffs are not jointed nor brecciated, except for local 
vertical jointing of the Rainier Mesa tuff, which is intruded by the dike at its 
shallowest level. The contact of the dike and host tuff is preserved in places and 
varies from partly to completely welded in the same manner as described above 
for the PR dike. Where complete welding has occurred, vesicles are vertical and 
parallel the dike margin. Contact welding of the host tuffs formed oblate fiamme 
that parallel the dike-host contact. Visible thermal effects on the wall rocks 
disappear within 1 m of the dike margin. 
This analogue study suggests that zones of change in rock properties (i.e., formation of 
vitrophyres and/or various degrees of welding of the host rock and formation of fiamme, which 
are flattened glassy inclusions) are limited to between a few tens of centimeters to, at most, a 
meter perpendicular to the dike. Also, features such as the platy texture along the dike margins 
and vesicles in the welded tuff, are oriented parallel to the dike margins. 

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Potential Effects on PermeabilityThe following discussion on the potential for an intrusion to 
impact permeability includes an evaluation of the orientation of a possible future dike, since 
orientation could affect the consequences of an intrusion. Most researchers conclude that when 
ascending dikes enter the shallow upper crust, their location and orientation is influenced by the 
orientation of the local stress field and the presence of faults that may locally control alignment. 
The evidence cited for this conclusion, in addition to the interaction of faults and dikes at the 
Paiute Ridge center described above, includes several northeast-oriented vent alignments in the 
Yucca Mountain region and the association of eruptive centers with known or inferred faults 
(CRWMS M&O 1996 [DIRS 100116], Appendix E, p. AM-4); Connor et al. 1996 
[DIRS 135969], p. 78). 
The results of the PVHA are summarized in the analysis report Characterize Framework for Igneous 
Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989]), which presents probability 
distributions for the length and orientation of possible future volcanic dikes near the repository. 
The aggregate dike-length distribution derived from the PVHA has a mean value of 4.0 km, and 
the most commonly assigned dike orientation centers on N30E (BSC 2004 [DIRS 169989], 
Section 6.3.2). The anisotropic transmissivity observed in the SZ in the Yucca Mountain region 
has a maximum principal transmissivity direction of approximately N15E (BSC 2004 
[DIRS 170042], Section 6.5.2.10), which is generally consistent with the fault and fracture 
orientations. A corroborative analysis by Ferrill et al. (1999 [DIRS 118941], p. 1) indicated a 
N30E orientation. A north-to-northeast orientation parallels or sub-parallels the faults and 
fractures active in the present-day in situ stress field. Dike features that may form in the future, 
such as the platy texture and welded surfaces that could affect permeability, will parallel the dike 
orientation and will likely be aligned in a north-to-northeast orientation. 
This parallel to subparallel orientation of dikes and maximum principal transmissivity, coupled 
with the expected limited affected volume of material around the dikes, indicates that dikes, even 
if differing in permeability, will not significantly affect groundwater flow patterns at the 
mountain scale. By way of corroboration, an early analysis of the effect of a dike on flow in the 
SZ was conducted and documented in Chapter 10 of the TSPA-VA (CRWMS M&O 1998 
[DIRS 100369], Section 10.4.4). The corroborative analysis suggested that there would be 
negligible impact for a dike oriented north to northeast. The analysis included a variety of dike 
lengths and locations respective to the repository area. Additionally, the occurrence of such a 
change is conditional on a low probability event of an igneous intrusion. 
The report Synthesis of Volcanism Studies for the Yucca Mountain Site Characterization Project 
(CRWMS M&O 1998 [DIRS 105347], p. 5-56) mentions the possibility of perched water 
forming near low-permeability intrusive bodies, and a concern regarding the potential for a dike 
to provide a barrier to flow and/or cause impoundments. Because of the parallel to subparallel 
orientation of dikes with the existing orientation of the anisotropic maximum horizontal 
permeability in the SZ, a dike would not form a barrier or impoundment that would have any 
significant effect on flow in the SZ. In the UZ, the primary direction of groundwater flow is 
vertically downward through the fractures. Because the joints on a dike margin would be near 
vertical, the formation of a significant perched water zone would be dependent on the formation 
of a sill. The potential impact of sill formation is addressed in the FEP 1.2.04.03.0A (Igneous 
intrusion into repository). The formation of a perched water zone is addressed in the 

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FEP 2.2.07.07.0A (Perched water develops). Drainage from a perched water zone is addressed 
in FEP 2.2.06.03.0A (Seismic activity alters perched water zone). 
Potential Effects on Faults and FracturesChange in fault and fracture properties due to igneous 
activity (i.e., activation, creation, and sealing of faults and fractures) is judged to be of negligible 
impact on three bases. First, the orientation of the faults and fractures (and possible future dikes) 
is generally parallel-to-subparallel to the maximum principal transmissivity in the SZ, so 
alteration of the faults or fractures is considered to have minimal effect as discussed previously. 
Additionally, the effect of changes in aperture (i.e., the mathematical equivalent of sealing or 
reactivation) have been examined (BSC 2004 [DIRS 170012], Appendix D) and found to have 
negligible impact on transport; changes in fault properties were excluded from further 
consideration in TSPA-LA on that basis. Lastly, the potential for volcanic-generated seismic 
events was considered within the context of the PSHA and included implicitly in the 
probabilistic assessment of seismic ground motion hazards (see FEP 1.2.03.03.0A, Seismicity 
associated with igneous activity). The PSHA seismic source characterization was also used as 
the basis for the approach to estimating probabilistic fault displacements. Thus, displacements 
from igneous events have been implicitly included in evaluation of probabilistic fault 
displacement (i.e., reactivation and creation of new faults) and further consideration is 
unwarranted. 
Potential Effects on MineralogyWith regard to mineral alterations changing the chemical 
response of the host rock to contaminants, it is possible that the thermal and geochemical 
influence of igneous activity could affect the rock mineralogy surrounding the igneous intrusion. 
However, mineral alterations around igneous intrusions at natural-analogue sites are generally 
confined to relatively thin zones (CRWMS M&O 1998 [DIRS 105347], pp. 5-41 and 5-57). In 
particular, natural-analogue studies in similar host rocks at the Nevada Test Site show that 
alteration is limited to a zone less than 10 m away from the intrusion/host rock contact (CRWMS 
M&O 1998 [DIRS 105347], pp. 5-41 and 5-71). Synthesis of Volcanism Studies for the Yucca 
Mountain Site Characterization Project (CRWMS M&O 1998 [DIRS 105347], p. 5-42) further 
states, Based on natural-analogue sites, there is no indication for extensive hydrothermal 
circulation and alteration, brecciation and deformation related to magmatic intrusion, and vapor 
phase recrystallization during the magmatic intrusion into the vitric and zeolitized tuffs. 
Because the alteration zone around dikes is limited to the immediate proximity of the dike, and 
the mineralogical changes are not adverse, then (at the scale of the repository) the changes in 
mineralogy would be of low consequence. 
SummaryIn summary, each concern posed in the FEP description has been evaluated based on 
site data and analyses or natural analogues. The subparallel orientation of potential future dikes 
to transmissivity, coupled with the expected limited affected volume indicate that dikes, even if 
differing in permeability, will not significantly affect groundwater flow patterns. Because the 
joints on the dike margin are near vertical, the formation of a perched water zone would be 
dependent on the formation of a sill. Furthermore, natural-analogue studies show that mineral 
alteration is limited to a zone less than 10 m away from the contact at the Nevada Test Site 
natural-analogue site, and alteration would not form minerals that would have adverse impacts 
on radionuclide transport. Consequently, changes in rock properties due to igneous activity do 
not provide a mechanism to significantly affect exposure or release of radionuclides to the 

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accessible environment. Therefore, the FEP is excluded from the TSPA-LA based on low 
consequence. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.2.2 Igneous Intrusion into Repository (1.2.04.03.0A) 
FEP Description: Magma from an igneous intrusion may flow into the drifts and 
extend over a large portion of the repository site, forming a sill, 
dike, or dike swarm, depending on the stress conditions. This 
intrusion could involve multiple drifts. The sill could be limited to 
the drifts or a continuous sill could form along the plane of the 
repository, bridging between adjacent drifts. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: The primary focus of this FEP is magmatic intrusion directly into 
the repository. The following FEP discussion addresses the 
potential for such an intrusion and the resulting in-drift conditions 
and waste package damage, which are included within the 
TSPA-LA. Analysis model reports supporting the Screening 
Decision contain tables of included FEPs with pointers to more 
detailed background information on this FEP (BSC 2004 
[DIRS 169989], Table 6-1; BSC 2004 [DIRS 169980], Table 6-1; 
BSC 2004 [DIRS 170028], Table 6-1]). Related FEPs discuss 
changes in hydrology and rock properties. 
The technical basis for inclusion of this FEP is based on the results of Characterize Framework for 
Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989], Table 6-21), which 
indicates that the computed mean annual frequency of intersection of the LA repository footprint 
by a dike is 1.7  10-8 (see Assumption 5.1 in Section 5). The computed 5th and 95th percentiles 
of the uncertainty distribution for frequency of intersection are 7.4  10-10 and 5.5  10-8, 
respectively. Because of the low mean probability and the probability distribution, as 
determined in the PVHA (CRWMS M&O 1996 [DIRS 100116]), multiple independent events 
are not further addressed in TSPA. The PVHA presented a slightly lower annualized mean 
probability of 1.5  10-8, but this was obtained using a somewhat different and smaller repository 
footprint (CRWMS M&O 1996 [DIRS 100116], p. 4-10). 
Igneous intrusion into the repository (i.e., igneous activity), as indicated in the FEP description, 
has the potential to affect both the geochemical and hydrologic characteristics of the site (see 
FEPs 1.2.04.02.0A and 1.2.10.02.0A for discussions of rock properties and hydrologic impacts, 
respectively) and, due to extreme changes in the in-drift environment, could damage EBS 

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ANL-WIS-MD-000005 REV 02 6-55 November 2004 
components and the waste packages. This damage could result in the release of radionuclides 
and affect the radiological exposure of the RMEI. 
Because the probability of igneous intrusion is greater than the FEP screening probability 
threshold and because waste package damage cannot be constrained due to the thermal, 
mechanical, and geochemical environment associated with an intrusion into an emplacement 
drift, igneous intrusion into the repository is included within the TSPA-LA. The environmental 
conditions and their effect on waste packages are discussed in the FEP 1.2.04.04.0A (Igneous 
intrusion interacts with EBS components). 
The TSPA-LA approach for incorporating igneous intrusion is outlined in Total System 
Performance Assessment-License Application Method and Approach (BSC 2003 [DIRS 166296], 
Section 8.1.2) and Total System Performance Assessment (TSPA) Model for the License 
Application (BSC 2004 [DIRS 168504], Section 6.4). The two igneous events (with individual 
probabilities and consequences) modeled by the TSPA-LA are: 
 An igneous intrusion groundwater transport modeling case featuring the ascent of a 
basaltic dike or dike system (i.e., a set, or swarm of multiple dikes comprising a single 
intrusive event) to the repository level where it intersects drifts (this FEP) 
 A volcanic eruption modeling case featuring the development of one or more volcanoes 
within the repository footprint, each with a conduit that may intersect waste packages 
(FEP 1.2.04.06.0A). 
As a consequence of the first event, which is non-eruptive, waste from breached packages may 
provide a source of radionuclides when groundwater moves through the damaged packages at 
some time in the future (igneous intrusion groundwater transport modeling case). The potential 
consequence of the second event (volcanic eruption modeling case) is that waste packages 
entrained within a conduit may be breached, releasing radionuclides in an erupting ash plume 
where they can be dispersed downwind to the RMEI. The location of the RMEI is 
approximately 18 km south of the repository, as defined in 10 CFR 63.312 and 10 CFR 63.302 
[DIRS 156605]. 
For the igneous intrusion groundwater transport modeling case, all waste packages in intersected 
drifts are assumed to provide no further protection and waste is available for release through 
groundwater flow and transport process. The analysis report, Characterize Eruptive Processes at 
Yucca Mountain, Nevada (BSC 2004 [DIRS 169980], Section 6) presents information about 
volcanic systems and the parameters that can be used to model their behavior. In particular, that 
report addresses the geometry of volcanic feeder systems, which is of primary importance in 
predicting how much of a repository would be affected by an intrusion. The factors of concern 
include the probability of the event occurring and the number of drifts and waste packages 
affected by the igneous intrusion. The particular form of the intrusion (a dike, dike swarm or 
sill) is of lesser concern. As described below, the model for igneous intrusion allows for the 
intrusion of multiple drifts and damage to the waste packages within each of the intruded drifts. 

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ANL-WIS-MD-000005 REV 02 6-56 November 2004 
The manner in which the igneous intrusion is incorporated into the TSPA-LA igneous intrusion 
groundwater transport modeling case includes (BSC 2003 [DIRS 166296], Section 5.2): 
 The timing of the igneous intrusion during the 10,000year modeling period 
 Assessment of the number of waste packages hit in an igneous intrusion. 
The TSPA-LA Model for the igneous intrusion modeling case considers a single igneous 
intrusion event per realization. The time of the igneous intrusion is selected from a log-uniform 
distribution of possible event times with the minimum equal to the end of the first time step and 
the maximum equal to the end of the simulation period (BSC 2004 [DIRS 168504], 
Section 6.4.1.1). 
For each TSPA realization, a cumulative distribution function (CDF) is sampled to determine the 
number of impacted waste packages to use as the source term. The CDF is based on a series of 
3000 realizations of dike swarm configurations that could intersect the repository (BSC 2004 
[DIRS 170001], Section 6.3). Computationally, an average CDF for the numbers of waste 
packages hit is obtained by overlaying the 3,000 dike swarm configurations onto the repository 
layout geometry and summing up the number of drifts intersected for each realization. The CDF 
is based on the TSPA-LA assumption that all waste packages in an intersected drift are 
compromised. The CDF is also based on a magma bulkhead analyses that concludes magma is 
contained within an intersected drift (BSC 2004 [DIRS 170001], Section 6.3). The FEP 
Igneous intrusion interacts with EBS components (1.2.04.04.0A) provides additional detail on 
post-intrusion affects, including behavior of the waste package. 
Neither the TSPA-LA nor the supporting models provide results for an initial eruption of 
pyroclastic magma into the drifts. In this way, the models implicitly define the manner in which 
igneous intrusion into the repository (by effusive flow) is included in the TSPA-LA model; that 
is, by defining the maximum length of all intersected drifts that are involved in the direct flow 
path and totaling the number of waste packages in those drifts. 
Supporting Reports: Characterize Framework for Igneous Activity at Yucca Mountain, Nevada 
ANL-MGR-GS-000001 (BSC 2004 [DIRS 169989]) 
Characterize Eruptive Processes at Yucca Mountain, Nevada 
ANL-MGR-GS-000002 (BSC 2004 [DIRS 169980]) 
Dike/Drift Interactions 
MDL-MGR-GS-000005 (BSC 2004 [DIRS 170028]) 
6.2.2.3 Igneous Intrusion Interacts with EBS Components (1.2.04.04.0A) 
FEP Description: An igneous intrusion in the form of a dike may occur through the 
repository, intersecting the repository drifts, resulting in magma, 
pyroclastics, and volcanic gases entering the drift and interacting 
with the EBS components (drip shields, waste packages, pallet, and 
invert). This could lead to accelerated drip shield and waste 
package failure (e.g., attack by magmatic volatiles, damage by 

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ANL-WIS-MD-000005 REV 02 6-57 November 2004 
flowing or fragmented magma, thermal effects) and dissolution or 
volatilization of waste. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: The primary focus of this FEP is interactions between the 
intrusion, the waste, and the waste packages. These interaction 
are included in the TSPA-LA because magma could interact with 
the elements of the EBS and the waste packages could be impaired 
due to perturbations of the drift environment, thereby resulting in 
damage to the waste packages and mobilization of waste. Analysis 
model reports supporting the Screening Decision contain tables of 
included FEPs with pointers to more detailed background 
information on this FEP (BSC 2004 [DIRS 169980], Table 6-1; 
BSC 2004 [DIRS 170028], Table 6-1; BSC 2004 [DIRS 170001], 
Table 6-1). 
The technical basis for inclusion of this FEP is based on the results of Characterize Framework for 
Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989], Table 6-21), which 
indicates that the computed mean annual frequency of intersection of the LA repository footprint 
by a dike is 1.7  10-8 (see Assumption 5.1 in Section 5). The computed 5th and 95th percentiles 
of the uncertainty distribution for frequency of intersection are 7.4  10-10 and 5.5  10-8, 
respectively. The PVHA (CRWMS M&O 1996 [DIRS 100116], p. 4-10) presented a lower 
annualized mean probability of 1.5  10-8, but this was obtained using a somewhat different and 
smaller repository footprint. 
Igneous intrusion into the repository (i.e., igneous activity), as indicated in the description for 
FEP 1.2.04.03.0A, has the potential to affect both the geochemical and hydrologic characteristics 
of the site (see FEPs 1.2.04.02.0A and 1.2.10.02.0A for discussions of rock properties and hydrologic 
impacts respectively). Due to extreme changes in the in-drift environment, igneous intrusion could 
damage EBS components and the waste packages. This damage could result in the release of 
radionuclides and affect the radiological exposure of the RMEI. 
Because the probability of igneous intrusion is greater than the FEP screening probability 
threshold and because waste package damage cannot be constrained due to the thermal, 
mechanical, and geochemical environment associated with an intrusion into an emplacement 
drift, igneous intrusion interacts with EBS components is included within the TSPA-LA; and the 
environmental conditions and their effect on waste packages are discussed in this FEP. 
Transport of radionuclides by groundwater from waste entrained in basalt after seepage has been 
re-established is considered under FEP 1.2.04.04.0B (Chemical effects of magma and magmatic 
volatiles). 
The TSPA-LA approach for incorporating igneous intrusion is outlined in Total System 
Performance Assessment-License Application Method and Approach (BSC 2003 [DIRS 166296], 
Section 8.1.2) and Total System Performance Assessment (TSPA) Model for the License 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-58 November 2004 
Application (BSC 2004 [DIRS 168504], Section 6.4). The two igneous events (with individual 
probabilities and consequences) being modeled by the TSPA-LA are: 
 An igneous intrusion groundwater transport modeling case featuring the ascent of a 
basaltic dike or dike system (i.e., a set or swarm of multiple dikes comprising a single 
intrusive event) to repository level where it intersects drifts 
 A volcanic eruption modeling case featuring the development of one or more volcanoes 
within the repository footprint, each with a conduit that may intersect waste packages. 
As a consequence of the first event, which is non-eruptive, waste from breached packages may 
provide a source of radionuclides when groundwater moves through the damaged packages at 
some time in the future (igneous intrusion groundwater transport modeling case). The potential 
consequence of the second event (volcanic eruption modeling case) is that waste packages 
entrained within a conduit may be breached, releasing radionuclides in an erupting ash plume 
where they can be dispersed downwind to the RMEI. The location of the RMEI is defined as 
being approximately 18 km south of the repository (10 CFR 63.312 and 10 CFR 63.302 
[DIRS 156605]). Regardless of whether there is an eruption or not, any igneous event that 
intersects the repository will result in magmatic materials interacting with EBS components, 
either directly in Zone 1 (intersected emplacement drifts) or possibly indirectly in Zone 2 
(emplacement drifts that are not intersected). In the following paragraphs, the potential 
consequences of a possible future igneous intrusion are constrained as a result of analyses of the 
interaction of the drift and other EBS components with magma effusively flowing into an 
intersected drift. Neither the TSPA-LA nor the supporting models provide results for a 
pyroclastic magma. The models implicitly define the manner in which igneous intrusion into the 
repository (by effusive flow) is included in the TSPA-LA model-that is, by defining the 
maximum length of all intersected drifts that are involved in the direct flow path and totaling the 
number of waste packages in those drifts. 
The model report, Dike/Drift Interactions (BSC 2004 [DIRS 170028], Section 6), provides 
conclusions related to various factors influencing post-intrusion environmental conditions within 
the drifts. The outputs of the model indicate that the entire length of an intersected drift has the 
potential to be filled with magmatic materials (BSC 2004 [DIRS 170028], Section 6.4). Several 
lines of evidence suggest that an igneous intrusion will compromise the structural integrity of 
waste packages exposed to magma. The temperature of the intruding magma will be at, or near 
the thermal limitations of the waste package materials. Also, during the course of magma 
cooling, waste packages and canisters and assemblies may be subject to corrosion (BSC 2004 
[DIRS 170028], Section 6.4.8.1). The evaluation of potential damage mechanisms supports the 
TSPA-LA assumption that waste packages in Zone 1 (intersected) drifts will provide no 
protection for the contained waste. 
Relative to the volatilization or dissolution of the potentially exposed waste form in Zone 1 
drifts, Dike/Drift Interactions (BSC 2004 ([DIRS 170028], Section 6.8.8.3) provides information 
that indicates that spent commercial nuclear fuel, which is a ceramic composed of UO2, will not 
melt or volatilize in a basalt magma. The melting temperature of the ceramic ranges from 
approximately 2600C to 2800C, while the temperature of the magma is over a thousand 
degrees less (up to approximately 1169C). Therefore, melting or volatilization of spent fuel 

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does not need to be considered further. However, when waste packages and fuel claddings are 
damaged, the fuel pellets may be assimilated into cooling basalt magma. As temperatures 
decrease after magma emplacement, UO2 is expected to fragment, which increases the surface 
area of the waste (BSC 2004 ([DIRS 170028], Section 6.4.8.3). Under this scenario, two types 
of processes are expected: chemical interaction between waste forms and the magma, and 
chemical interaction between the waste forms and the metal of waste package materials and 
cladding. Dike/Drift Interactions (BSC 2004 ([DIRS 170028], Section 6.4.8.3) indicates that 
uranium metal may form as well as various U-Zr alloys. In addition, radionuclides in the waste 
could be incorporated into crystallizing silicate mineral phases or form higher oxide phases. The 
thermodynamic stability of secondary phases likely to form in cooling basalt is poorly known 
and it is difficult to predict which phases, if any, might form. Fission products (cesium, 
technetium, etc.) may also be incorporated into new mineral phases, with the size and charge of 
fission-product ions exerting primary control as to the resulting minerals that might contain 
them. Thus, there is great uncertainty as to which phases and minerals are likely to 
accommodate the suite of radionuclides in spent-fuel. 
As stated in Dike/Drift Interactions (BSC 2004 ([DIRS 170028], Section 6.4.8.3), a significant 
fraction of waste packages within the repository will contain radionuclides in a glass matrix. 
Assuming glass waste is contained within waste packages, glass would be expected to re-melt 
and re-solidify as the drift is intruded and then cools. Less certain, however, are possible 
interactions between exposed and partially degraded glass waste and basalt magma. Given the 
low melting temperature of glass waste and the large difference in composition between glass 
waste and basalt magma, some reaction between them would be inevitable. The interaction 
might result in the rimming of olivine crystals with pyroxene or the crystallization of pyroxene, 
rather than olivine in regions of the cooling drift that are rich in glass. Much like spent fuel, 
however, there remains considerable uncertainty as to the exact nature of materials that may 
form through glass-magma interactions (BSC 2004 [DIRS 170028], Section 6.4.8.3). 
As summarized in BSC 2004 ([DIRS 170028], Section 6.8.6), although the range of possible 
secondary mineral phases that may form cannot presently be constrained, they are nonetheless 
expected to comprise silicate and oxide minerals, rather than salts. As oxide and silicate 
minerals tend to have slow dissolution rates compared to salts, significantly enhanced dissolution 
rates of minerals due to reaction of waste with basalt magma within drifts is not anticipated and 
is not considered further. 
The potential for damage to waste packages and waste forms in Zone 2 from heat and migrating 
gas, is also examined in Dike/Drift Interactions (BSC 2004 [DIRS 170028], Section 6.6). That 
modeling effort leads to a conclusion that the properties of the host rock and the presence of 
filled keyways at the ends of the emplacement drifts preclude damage in non-intersected drifts 
from heat and gas migration from intersected drifts. The fractured and porous rock, as well as 
the crushed tuff used to fill the perimeter drifts, does represent a possible path for gas flow 
resulting from magma. However, the results described below indicate that this is not a concern. 
Relative to heat effects, if a drift was quickly and entirely filled with basaltic magma at a 
temperature of approximately 1150C, the tuff surrounding the drift would begin to heat up as 
the magma cooled. With magma cooling and solidification, the temperature profile through the 
drift and surrounding rock would be expected to decrease with time. The temperature 

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ANL-WIS-MD-000005 REV 02 6-60 November 2004 
distribution for magma filling a Zone 1 emplacement drift can be estimated using an idealized 
model of one-dimensional unsteady heat conduction in a cylinder. Simulations show that initial 
temperatures for host rock near the drift are high and attenuate rapidly into the surrounding tuff 
(BSC 2004 [DIRS 170028], Figures 6-98 and 6-99). Outside the drift, peak temperatures are 
always less than magmatic temperatures and are not reached until sufficient time has passed to 
accommodate conductive heating of the wall rock. For example, the peak temperature at a 10-m 
radius is less than boiling and is attained only after one year from the time of intrusion. The 
temperature reaches near ambient conditions of approximately 30C at drift center in 
approximately 30 years (BSC 2004 [DIRS 170028], Figures 6-98 and 6-99). The analysis also 
shows that the maximum temperature rise in an adjacent, unaffected drift (Zone 2) is small (less 
than 10C) because the host rock provides an effective thermal barrier to the impacts of heat 
transfer from magmatic intrusion. Therefore, heat effects in Zone 2 drifts are not a concern and 
are not considered further. 
Relative to magmatic gas movement between drifts, gases that are exsolved from the cooling 
basalt would enter the wall rock and migrate away from the intruded Zone 1 drifts. The 
following discussion describes the effects on waste packages in Zone 2 of gases migrating from 
Zone 1 drifts. 
Simulations of gas flow between drifts were conducted (BSC 2004 [DIRS 170028], 
Sections 6.6.5.2) and results indicated that after 6 months (BSC 2004 [DIRS 170028], 
Figure 6-89) relatively high CO2 and SO2 concentrations occur well outside the intruded drift, 
with localized high HCl and HF concentrations close to the drift. After 1 year, the regions of 
high CO2 and SO2 concentrations have continued to migrate slowly outward, with a small 
decline in their maximum concentrations. In contrast, gas phase HCl and HF relative 
concentrations have decreased dramatically to values below 10-9 as a result of cooling and 
dissolution into fracture condensate and matrix pore water. Over an extended period (500 years), 
CO2 concentrations slowly decline toward the ambient value of approximately 10-3 (volume 
fraction) from the initial volcanic gas composition of approximately 0.14 with no noticeable 
effect on the adjacent Zone 2 drift. SO2 concentrations decline much more slowly as a result of 
its lower solubility and smaller diffusivity, with concentrations on the order of 1 ppmv, reaching 
the Zone 2 drift after 500 years (BSC 2004 [DIRS 170028], Figure 6-91). This simulation 
assumes that there is no longer any waste-generated heat output from the Zone 2 drift (that would 
result in a less penetrable boiling/condensation zone) and that there is no air flow through the 
drift to dilute the gas. Although gas-phase SO2 concentrations for this simulation are elevated 
relative to the background, no impacts are anticipated for Zone 2 waste packages. 
A separate simulation was done to evaluate gas transport through the filled keyway at the drift 
turnout (BSC 2004 [DIRS 170028], Section 6.6.5.3). The simulation considers a volcanic gas 
consisting of only water vapor, CO2, and SO2. The volcanic gas temperature is fixed to 300C, 
and the pressure is at the ambient value of approximately 88 kPa. This model considers a 
horizontal region (about 5.5 m in width) filled with crushed tuff extending from the drift wall to 
the right boundary of the model. The fill material is given the same porosity (0.545) as the invert 
fill. 
Simulation results (BSC 2004 [DIRS 170028], Section 6.6.5.3) indicate that gas transport is 
more rapid through this material, reaching the model boundary 40.5 m away in less than 

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ANL-WIS-MD-000005 REV 02 6-61 November 2004 
1.5 months. Temperatures are depressed in this filled zone relative to that in the rock because of 
the low thermal conductivity of this mostly gas-filled porous material and the lack of a 
significant advective component out of the drift, which would result in higher temperatures and 
faster gas migration. As the gas migrates through the filled connecting drifts and into a 
neighboring emplacement drift, the volcanic gas will be diluted by air, and as the gas source 
from the magma declines over time, the extent of dilution by air will increase. The crushed tuff 
filling the connecting drifts would likely have some initial water content and, therefore, 
retardation of the gas would likely be somewhat greater than the case modeled (BSC 2004 
[DIRS 170028], Section 6.6.6). Therefore, it is concluded that the combination of dilution of the 
magmatic gas by air and retardation of the gas by moisture in the filled keyway material is 
expected to result in no damage to waste packages in Zone 2 drifts. Only waste packages in 
Zone 1 emplacement drifts can contribute to dose. 
In the event of an igneous intrusion, intersected drifts will fill with magma and compromise 
waste packages in that drift. The possibility for magma to flow between drifts is assessed in a 
calculation (BSC 2004 [DIRS 171070]). The calculation assessed the sealing efficiency of a 
filled keyway at the drift turnout, the key being composed of a sand fill emplaced in a v-shaped 
roof keyway (plug). The calculations include numerical simulations performed with the 
computer code, FLAC. It was assumed in this study that magma entered the chamber formed at 
the backside of the plug under 6-8 MPa pressure. Two arguments based on mechanical and 
fluid-thermal considerations were used to assess the efficiency of the plug. The first argument, 
based on plug compressibility and plastic flow, evaluates the extent of closure occurring in the 
gap on the front side and the gap inside the access main behind the plug under mechanical 
pressure of the magma in the chamber. The second argument relies on the maximum distance 
that magma can infiltrate through the sandfill before its temperature reaches the effective 
solidification temperature due to partial crystallization. It was found that the distance magma 
can infiltrate before it freezes is only a fraction of the length of the gap closure. Therefore, 
magma filling a drift resulting from intersection with an igneous dike (Zone 1) will not be able to 
reach and compromise other waste packages in non-intersected drifts (Zone 2). 
The analysis provided in Number of Waste Packages Hit by Igneous Intrusion (BSC 2004 
[DIRS 170001]) uses repository design information and outputs from the analysis reports 
Characterize Framework for Igneous Activity at Yucca Mountain, Nevada (BSC 2004 
[DIRS 169989]), and Characterize Eruptive Processes at Yucca Mountain, Nevada (BSC 2004 
[DIRS 169980]) to calculate the number of waste packages exposed to Zone 1 (intersected drifts) 
magmatic environments. The analysis uses spreadsheet calculation operations to evaluate 
geometric relationships between dike intersection area and conduit geometry and the number of 
waste packages impacted by dikes and conduits. 
The number of waste packages hit analysis results (BSC 2004 [DIRS 170001], Section 6.3.4]) 
include CDFs for the number of waste packages impacted in an igneous intrusion scenario and in 
an eruptive release scenario. These CDFs are used directly and explicitly in the TSPA-LA model 
to determine the source term for the igneous event scenarios. Because the CDFs are dependent 
on the underlying inputs, the underlying inputs and related FEPs are considered implicitly 
included in the TSPA-LA model. 

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ANL-WIS-MD-000005 REV 02 6-62 November 2004 
From the above discussion, interactions of the intrusion with Zone 1 are implemented within the 
TSPA-LA. These interactions are incorporated into the TSPA-LA as assumptions or parameters 
as follows: 
 Assumptions underlying the igneous intrusion groundwater transport modeling case 
involving the waste package and waste form 
 Parameters related to resumption of seepage following cooling of the drift after the 
magmatic intrusion. 
Within the TSPA-LA, no credit is taken for any partial protection that residual elements of the 
waste package shells and the encapsulating basalt might provide (BSC 2004 [DIRS 170028], 
Section 6.4.8.1). Waste form solubilities from the nominal case are used to evaluate radionuclide 
transport for the igneous intrusion groundwater transport case. 
Within TSPA-LA, lookup tables are used to model magma temperature as a function of time for 
the center of the cooling magma body. These look-up tables determine when seepage is 
reestablished, exposing the encased waste form to seepage flux. The abstraction considers the 
temperature of the waste form for a period of 100 years following intrusion. The decline in 
temperature of the waste form and magma body is related to the temperature due to waste heat 
alone at 25C, 50C, 100C, 150C, and 200C. Each waste form starting temperature represents 
a different thermal evolution (BSC 2004 [DIRS 168504], Section 6.4.1.1.2). 
Early in the cooling history, the temperatures for times between zero and the length of the 
TSPA-LA time step (10 years) are sampled uniformly. The temperatures for times greater than 
the TSPA-LA time step, but less than 100 years are taken directly from the look-up tables 
(BSC 2004 [DIRS 168504], Section 6.4.1.3). 
Temperatures are used in the EBS multi-scale thermal model to determine the waste and invert 
relative humidity, invert saturation, and invert liquid flux for each waste package type in each 
percolation subregion after an igneous intrusion (BSC 2004 [DIRS 168504], Section 6.4.1.3). 
After 100 years, all TSPA-LA model variables, including temperatures, revert back to the 
nominal scenario thermal-hydrologic abstraction values (BSC 2004 [DIRS 168504], 
Section 6.4.1.1.2). 
Following resumption of seepage, the abstraction used for the TSPA-LA model will use typical 
seepage flux from the crown, as justified in Dike/Drift Interactions (BSC 2004 [DIRS 170028], 
Section 5.4.1). FEP 1.2.04.04.0B describes the TSPA method used to simulate basalt-seepage 
water reactions within the drift for the igneous intrusion groundwater transport model. With 
regard to the volcanic eruption modeling case, the model report Atmospheric Dispersal and 
Deposition of Tephra from a Potential Volcanic Eruption at Yucca Mountain, Nevada 
(BSC 2004 [DIRS 170026]) provides the analysis of a potential eruption through the repository. 
FEPs 1.2.04.06.0A (Eruptive conduit to surface intersects repository) and 1.2.04.07.0A (Ashfall) 
describe how eruption scenarios are incorporated into the TSPA-LA. 

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ANL-WIS-MD-000005 REV 02 6-63 November 2004 
Supporting Reports: Characterize Eruptive Processes at Yucca Mountain, Nevada 
ANL-MGR-GS-000002 (BSC 2004 [DIRS 169980]) 
Dike/Drift Interactions 
MDL-MGR-GS-000005 (BSC 2004 [DIRS 170028]) 
Number of Waste Packages Hit by Igneous Intrusion 
ANL-MGR-GS-000003 (BSC 2004 [DIRS 170001]) 
6.2.2.4 Chemical Effects of Magma and Magmatic Volatiles (1.2.04.04.0B) 
FEP Description: An igneous intrusion into the repository may be accompanied by 
the release of magmatic volatiles. The volatiles may affect in-drift 
chemistry (potentially leading to increased waste package 
corrosion), or may be absorbed by the host rock, where they could 
change the chemistry of the water seeping back into the drift 
following the intrusive event. Seepage water chemistry following 
magma cooling could also be affected by flowing through and 
interacting with the intruded basalt. 
Screening Decision: Included 
Screening Argument: Not applicable 
TSPA Disposition: This FEP is concerned with both magmatic volatiles and their 
effect of water chemistry, and the basaltic magma that may fill one 
or more repository drifts and its effect on water chemistry. 
Analyses discussed below indicate that magmatic volatiles are not 
a concern and do not need to be considered further, while changes 
in water chemistry due to interaction with the basalt are included in 
the TSPA-LA. Analysis model reports supporting the Screening 
Decision contain tables of included FEPs with pointers to more 
detailed background information on that FEP (BSC 2004 
[DIRS 170028], Table 6-1). 
Relative to the potential impact of magmatic volatiles on water chemistry, magmatic volatile 
release may lead to zones of low pH in regions adjacent to potential igneous intrusions 
(BSC 2004 [DIRS 170028], Section 6.6). The high solubility of acidic volatiles indicates that the 
formation of low-pH fluids near the boiling point isotherm around Zone 1 drifts is likely. These 
low-pH fluids should be neutralized by hydrolysis reactions with feldspar and other minerals. 
The following equation (BSC 2004 [DIRS 170028], Eq. 6-112) clearly shows that hydrogen ions 
are consumed in hydrolysis reactions, leading to the neutralization of acidity. 
2NaAlSi3O8 (albite) + 2H+ + 9H2O . Al2Si2O5(OH)4 (kaolinite) + 4H4SiO4 + 2Na+ (Eq.6-1) 
Therefore, chemically aggressive fluids could exist near intruded drifts for some period 
following intrusion until the fluids are neutralized by natural processes. During the first year or 
two, temperatures at the edge of the drift remain above 100 C preventing seepage into the drift 

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ANL-WIS-MD-000005 REV 02 6-64 November 2004 
(BSC 2004 [DIRS 170028] Figure 6-88). Simulations suggest that the zone of decreased pH 
extends into the wall rock only a relative short distance, perhaps 20 or 25 m. Between one and 
five years, the narrow zone of decreased pH (approximately pH 7) is evident in simulations 
(BSC 2004 [DIRS 170028], Figure 6-93). These minor changes in pH indicate low impact to 
water chemistry. 
This analysis indicating low impact is supported by the arguments presented in 
FEP 1.2.04.02.0A (Igneous activity changes rock properties), which was excluded based on low 
consequence. In that FEP, natural analogue studies at Paiute Ridge (Carter Krogh and Valentine 
1996 [DIRS 160928], pp. 7 and 8) demonstrated that the zone of alteration around an igneous 
intrusion was generally limited to 1 m or less from the intrusive contact. Therefore, any impacts 
on water chemistry will be limited in both time and space, so this aspect of the FEP is not 
considered further. 
Migration of magmatic volatiles between drifts is addressed in FEP 1.2.04.04.0A (Igneous 
intrusion interacts with EBS components). Analyses presented there demonstrate that migration 
of magmatic volatiles to Zone 2 drifts (non-intersected drifts) is not a concern and does not need 
to be considered further (BSC 2004 [DIRS 170028], Section 6.6). Refer to FEP 1.2.04.04.0A for 
a complete discussion of this issue. 
Assuming that an igneous intrusion occurs and the magma subsequently cools to ambient 
conditions, seepage water is expected to flow through and react with the basalt in the intruded 
emplacement drifts. The chemical interaction of the seepage water chemistry with the 
mineralogy of basalt is included in the TSPA-LA as described below. 
The technical basis for inclusion of this process is based upon EQ3/6 software simulations 
involving interaction of seepage water with the basalt and the resulting hydrochemistry 
(BSC 2004 [DIRS 170028], Section 6.8). The EQ3/6 software package analyzes groundwater 
chemistry data, calculates chemical species and solubility limits, and determines the state of 
equilibrium for reaction of water and basalt to alter the pH of percolating water. 
Modeling of dissolution rates using EQ6 is based on a hypothetical 1-m block of basalt. The 
dissolution rates for basaltic minerals are derived from literature. The composition and flow rate 
of the water percolating through the basalt block are modeled using the EQ3-equilibrated Bin 8 
seepage water used in supporting calculations and analysis for the nominal case seepage 
abstraction. The water composition used in waterbasalt interaction sensitivity cases also 
includes Bin 11 seepage water and J-13 well water. These two water types represent seepage 
waters that are respectively, (1) more concentrated and (2) more dilute than the Bin 8 seepage 
water runs. Multiple calculations were based upon varied seepage rates, fCO2 values, matrix 
saturations, and mineral surface areas (BSC 2004 [DIRS 170028], Section 6.8). 
The water chemistry parameters required for use in TSPA are temporal values for pH and ionic 
strength. The temporal variation of pH and ionic strength, along with corresponding uncertainty 
in the form of maximum and minimum values are implemented in the TSPA-LA in look-up 
tables. The look-up tables present minimum and maximum parameter values for pH and ionic 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-65 November 2004 
strength as a function of time at and log (fCO2/bar) = -2, -2.5, -3, -3.5 and -4. The time intervals 
are defined in the TSPA-LA as follows (BSC 2004 [DIRS 170028], Section 6.8.4, Table 6-25): 
x = 25 years 
25> x = 250 years 
250 > x = 2500 years 
2500 > x = 20000 years 
The minimum and maximum of the time-weighted averages from the EQ3/6 calculations are 
consistent with the large time steps used in the TSPA-LA igneous intrusion groundwater 
transport model (BSC 2004 [DIRS 170028], Section 6.4.8.1). The two most important 
parameters affecting the solubility of radioelements include pH and fCO2. To use the solubility 
look-up table in Dissolved Concentration Limits of Radioactive Elements (BSC 2004 
[DIRS 169425]), a constant value for these parameters is used for any time interval (BSC 2004 
[DIRS 170028], Section 6.8.4.1). 
In some instances, TSPA-LA may need pH and ionic strength values for a range of parameters 
that are outside the range of values presented in the look-up tables. Such parameters include flux 
and log fCO2. For flux rates less than 50 mm/year, the look-up tables are used directly. For flux 
rates greater than 50 mm/year, a flux rate of 50 mm/year is used in the TSPA-LA. At this point, 
the pH and ionic strength of the water (equilibrated with atmospheric gas levels) percolating into 
the basalt block equals the pH and the ionic strength of the water leaving the basalt block. 
Results show that for flux rates above 50 mm/year, little or no reaction occurs (BSC 2004 
[DIRS 170028], Section 6.8.3). Convergence difficulties arise in EQ6 calculations carried out at 
high pH and low CO2 levels. Consequently, for TSPA-LA calculations where the log fCO2 is 
between -.4 MPa and -.5 MPa, the parameters for log fCO2 of -.4 MPa are used (BSC 2004 
[DIRS 170028], Section 6.8.3). 
Supporting Reports: Dike/Drift Interactions 
MDL-MGR-GS-000005 (BSC 2004 [DIRS 170028]) 
6.2.2.5 Magma or Pyroclastic Base Surge Transports Waste (1.2.04.05.0A) 
FEP Description: As a result of an igneous intrusion, extrusive processes may result 
in a pyroclastic density flow, base surge, dike apron, effusive lava 
flows, and/or development of a volcanic vent at land surface. 
Some of the waste (entrained, dissolved, or volatized) could then 
be transported away from the repository. Of most concern is 
transport directly along the land surface to the RMEI. 
Screening Decision: Excluded - Low Consequence. 
Screening Argument: This FEP is focused on near-surface eruption-related phenomena 
and on magmatic-related transport of entrained wastes. 

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ANL-WIS-MD-000005 REV 02 6-66 November 2004 
Hydrovolcanic phenomena also are addressed under this FEP. Due 
to the distance to the RMEI, and the low probability of a maar 
crater extending to the repository depth and exhuming waste, 
hydrovolcanic phenomena have been excluded based on low 
consequence. Incorporation and transport directly to the receptor 
biosphere by an ash plume and/or subsequent reworking of the 
deposited ash following an eruptive event is addressed separately 
in FEP 1.02.04.07.0A (Ashfall) and its companion 
FEP 1.02.04.07.0C (Ash redistribution via soil and sediment 
transport). 
The technical basis for exclusion for this FEP is presented in the following paragraphs. This 
basis relies in part on the definitions and concepts associated with the terms, accessible 
environment, controlled area and RMEI. These definitions and concepts indicate that the 
RMEI is located no closer to the repository than 18 km to the south (which is in the direction of 
groundwater flow) and over a contaminated groundwater plume, and that the limit of the 
controlled area is no greater than 5 km from the repository in any other direction (10 CFR 63.312 
and 10 CFR 63.302 [DIRS 156605]). In order for flowing lava or a pyroclastic base surge 
(potentially with entrained waste contained in them) to be of consequence to the accessible 
environment or the RMEI, it would have to travel across the land surface a distance of 5 to 
18 km. In contrast to these distances, Quaternary volcanoes in the vicinity of Yucca Mountain 
are small volume (approximately 0.1 km3 or less), and typically consist of a single main scoria 
cone surrounded by a small field of aa lava flows that extend approximately 1 km from the 
scoria cone (Characterize Framework for Igneous Activity at Yucca Mountain, Nevada, 
BSC 2004 [DIRS 169989], Section 6.2). Consequently, it is not credible to presume that 
extruded basalts with entrained wastes will extend beyond the controlled area, or to the RMEI 
located 18 km south of the repository. Pyroclastic surge deposits are also of limited geographic 
extent as will be described below. 
Pyroclastic deposits consist of a wide range of materials, transport mechanisms, and depositional 
environments. Pyroclastic eruptive mechanisms associated with Strombolian eruptions may 
result in transport of pyroclastic tephra (e.g., lapilli and ash) to distances sufficient to reach the 
RMEI. This aspect of an eruptive scenario has been included and is addressed separately in 
FEP 1.02.04.07.0A (Ashfall), and its companion FEP 1.02.04.07.0C (Ash redistribution via soil 
and sediment transport); they are not discussed further in this section. 
Of particular interest for this FEP are hydrovolcanic deposits or pyroclastic surge deposits. 
Hydrovolcanic deposits consisting mostly of ash are the result of density currents (surges) that 
leave distinctive thin (=1 cm) planar beds and cross-beds. Pyroclastic surge deposits at Lathrop 
Wells volcano have been observed and are inferred to represent hydrovolcanic eruptions during 
various stages of the evolution of the basalt center. A detailed description of hydrovolcanic 
deposits at an elevation of 863.8 m (2,834 ft), located 0.7 km northwest of the summit of Lathrop 
Wells volcano is provided in Characterize Eruptive Processes at Yucca Mountain, Nevada 
(BSC 2004 [DIRS 169980], Appendix C.3.3). Within the area flanked by the cinder cone and 
the protruding ridge of Miocene tuff there is a transition southward over a distance of 
approximately 400 m from thousands of thin beds of hydrovolcanic facies, to hundreds, and 
eventually to one or two resistant ash beds sandwiched between coarse lapilli beds. 

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ANL-WIS-MD-000005 REV 02 6-67 November 2004 
Observations in trenches immediately southwest of the cone also indicate a southward thinning 
hydrovolcanic sequence. BSC (2004 [DIRS 169980], Appendix C.3.3) notes that the field 
relations suggest that this limited deposit resulted from a ground-hugging sector blast (surge) 
directed to the northwest. Because the unit slopes approximately 8 degrees back toward the cone 
and projects to beneath the cone base, the exact relations are covered, but there are currently no 
field data indicating a concentric hydrovolcanic facies tuff ring (Wohletz 1986 [DIRS 140956], 
p. 262), such as might result from a large hydrovolcanic event. Also at the Lathrop Wells 
volcano, about 6-m below the south summit at an elevation of 954 m (3,130 ft), there is a 40-cm 
thick, well-sorted, finely bedded, cross-bedded ash and coarse ash deposit. This deposit appears 
to be the result of a brief hydrovolcanic event late in the cone-building history (BSC 2004 
[DIRS 169980], Appendix C.2.1). Crowe et al. (1986 [DIRS 101532], pp. 32 to 34) identified 
similar features in pyroclastic surge deposits at the southern and middle centers of the basalts of 
Nye Canyon. The Nye Canyon features were on the scale of 1 km or less. 
Given the lateral scale of the observed hydrovolcanic deposits (on the order of 1 km or less), it is 
not credible to presume that pyroclastic surges with entrained wastes will reach from the vent to 
the RMEI located 18 km south or to the controlled area boundaries at no greater than 5 km from 
the repository in other directions. 
A related concern is the possibility that a large steam explosion could occur, such that a large 
phreatic or a phreatomagmatic crater (maar) might form. Such a process could directly excavate 
waste and disperse it over a large area of the surrounding surface. Hydrovolcanic activity 
requires that rising magma encounter water in an aquifer(s) or a shallow water body at the 
ground surface (BSC 2004 [DIRS 169980], Section 6.1.3.2; Fisher and Schmincke 1984 
[DIRS 162806], pp. 231 to 264; Wohletz and Heiken 1992 [DIRS 105544], pp. 85 to 154). The 
resulting steam explosion finely fragments the magma and produces large amounts of kinetic 
energy. If the encounter occurs below the ground surface, the host rocks are fragmented and are 
incorporated in the eruption products, which are elevated in lithic clast content. For a large, 
disruptive steam explosion to occur, magma must come in rapid contact with a large volume of 
water at a shallow depth. Confining pressures must be sufficiently low to permit the formation 
of steam and to allow disruption of the surrounding rock as the steam violently expands. 
Crowe et al. (1986 [DIRS 101532], p. 47) suggest that a limited area of contact, such as a dike 
projecting through a thin (less than 10 m) aquifer, does not allow development of explosive 
instability, whereas contact with a standing body of water or thick (greater than 30 m) horizon of 
water-saturated rock permits water to vaporize at explosive rates. They also suggest that 
magma/water mixing and explosion associated with maars, tuff rings, and tuff cones generally 
occur at depths less than 200 m, which corresponds to a confining pressure of 5 MPa or less, but 
also acknowledge that deeper aquifers contribute to hydroexplosions as well. They note, 
however, that deep interaction at confining pressures above the critical point of water probably 
involves a different set of explosive mechanisms. 
Crowe et al. (1986 [DIRS 101532], Figure 19) present a plot of the relative frequency of crater 
depth for hydrovolcanic craters, maars, and tuff rings. The plot is positively skewed with a mean 
of 91 + 67 m, and the maximum crater depth is approximately 365 m. Crowe et al. (1986 
[DIRS 101532], pp. 58 to 59) conclude that, exhumation of a repository by explosive cratering 
associated with water/magma interaction is unlikely.the depth of burial of a repository at 
Yucca Mountain exceeds the crater depth of the largest known hydrovolcanic craters. 

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ANL-WIS-MD-000005 REV 02 6-68 November 2004 
However, this conclusion was based on a previously proposed repository depth of 380 m. The 
maximum overburden thickness of the currently planned TSPA-LA repository is approximately 
450 m (BSC 2003 [DIRS 166183], Section 4.2.1). The minimum depth to the TSPA-LA 
repository is 215 m (BSC 2004 [DIRS 164519]). The relative frequency of occurrence of 
hydrovolcanic craters greater than 215 m deep is less than approximately 10 to 15 percent 
(Crowe et al. 1986 [DIRS 101532], Figure 19). Note that the hydrovolcanic event is conditional 
on a geologic and hydrologic setting conducive to the occurrence of a hydrovolcanic event. 
Consequently, the net probability of occurrence of a 215-m hydrovolcanic crater associated with 
intrusion of the repository falls below the FEPs screening probability threshold. This assertion is 
based on: (1) a probability of 10 to 15 percent for a hydrovolcanic eruption resulting in a crater 
depth of 215 m or greater, (2) an assumed independence of a hydrovolcanic explosion from a 
dike intrusion into the repository, and (3) a calculated value of 1.3  10-8 for the mean 
probability of an eruptive center forming within the repository footprint (BSC 2004 
[DIRS 169989], Table 6-21). 
In addition to the low probability of occurrence of a very large (greater than 215-m deep) 
hydrovolcanic explosion, the distribution of existing hydrovolcanic deposits in the Yucca 
Mountain region is limited to a radius on the order of 1 km or less from the vent, which is 
insufficient to reach the controlled area boundary, and the TSPA-LA includes a volcanic eruption 
modeling case that distributes ash to the location of the RMEI. Consequently, transport by a 
hydrovolcanic cratering event as a separate modeling case can be excluded from the TSPA-LA 
based on low consequence. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 
6.2.2.6 Eruptive Conduit to Surface Intersects Repository (1.2.04.06.0A) 
FEP Description: As a result of an igneous intrusion, one or more volcanic vents 
may form at land surface. The conduit(s) supplying the vent(s) 
could pass through the repository, interacting with and entraining 
waste. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: FEP 1.2.04.06.0A (Eruptive conduit to surface intersects repository) 
is included in the TSPA-LA and is addressed through the modeling 
of an eruptive event. Consequences of an igneous intrusion 
through the repository and a resulting eruptive event are explicitly 
included in the TSPA-LA through the resulting ashfall, and the 
consequences are appropriately weighted by the probability of 
occurrence of the event. Analysis model reports supporting the 
Screening Decision contain tables of included FEPs with pointers 
to more detailed background information on this FEP (BSC 2004 

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ANL-WIS-MD-000005 REV 02 6-69 November 2004 
[DIRS 169980], Table 6-1; BSC 2004 [DIRS 170001], Table 6-1; 
BSC 2004 [DIRS 170026], Table 6-1; BSC 2004 [DIRS 169989], 
Table 6-1). 
The technical basis for inclusion of this FEP relies on the results of Characterize Framework for 
Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989]). Characterize 
Framework for Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989], 
Table 6-21) indicates that the annualized frequency of one or more eruptive centers occurring 
within the repository footprint as a result of an igneous intrusion is 1.3  10-8, which is greater 
than the low probability threshold for FEPs screening (see Assumption 5.1 in Section 5). 
Additionally, the lateral extent of an ashfall from such an event is sufficient to reach the location 
of the RMEI, so the FEP has been included. 
The TSPA-LA approach for addressing igneous intrusion is outlined in Total System 
Performance Assessment-License Application Method and Approach (BSC 2003 [DIRS 166296], 
Section 8.1.2) and Total System Performance Assessment (TSPA) Model for the License 
Application (BSC 2004 [DIRS 168504], Section 6.4). The two igneous events (with individual 
probabilities and consequences) modeled by the TSPA-LA are: 
 An igneous intrusion groundwater transport modeling case featuring the ascent of a 
basaltic dike or dike system (i.e., a set or swarm of multiple dikes comprising a single 
intrusive event) to the repository level where it intersects drifts (FEP 1.2.04.03.0A) 
 A volcanic eruption modeling case featuring the development of one or more volcanoes 
within the repository footprint, each with a conduit that may intersect waste packages 
(this FEP). 
As a consequence of the first event, which is non-eruptive, waste from breached packages may 
provide a source of radionuclides when groundwater moves through the damaged packages at 
some time in the future (igneous intrusion groundwater transport modeling case). The potential 
consequence of the second event (volcanic eruption modeling case) is that waste packages 
entrained within a conduit may be breached, releasing radionuclides in an erupting ash plume 
where they can be dispersed downwind to the RMEI. The location of the RMEI is assumed to be 
approximately 18 km south of the repository (10 CFR 63.312 and 10 CFR 63.302 
[DIRS 156605]). 
Properties and characteristics of the modeled basaltic eruption are described in Characterize 
Eruptive Processes at Yucca Mountain, Nevada (BSC 2004 [DIRS 169980], Section 6). The 
eruption characteristics used in the TSPA-LA model are based on the observed characteristics of 
past basaltic eruptions in the Yucca Mountain region and other analogous eruptions. For the 
volcanic eruption modeling case, a dike rises to the repository level, intersects one or more drifts 
in the repository, and proceeds vertically toward the surface. After lava in the dike encounters 
the ground surface, a fissure eruption develops, which proceeds to focus on one or more eruption 
sites as initial conduits are established. Conduits then develop from the surface downward. 
Conduits within the repository footprint are presumed in the TSPA-LA to be located randomly 
along intersecting dikes. It is presumed that where conduits intersect drifts, the waste packages 
in the intersected areas no longer provide any protection for the waste, which is then entrained in 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-70 November 2004 
a pyroclastic eruption. The model report, Atmospheric Dispersal and Deposition of Tephra from 
a Potential Volcanic Eruption at Yucca Mountain, Nevada provides the basis for assuming the 
erupted waste materials are finely divided particles amenable for airborne transport (BSC 2004 
[DIRS 170026], Section 6.5.2.16). 
Other eruptive scenarios have been considered. The model report, Dike/Drift Interactions 
(BSC 2004 [DIRS 170028]), provides conclusions related to various conceptual models for 
magma flow in drifts and on to the land surface, including consideration of the dog-leg 
scenario. The dog-leg scenario involves magma flow from the point of the dike/drift 
intersection to the end of the drift, where an eruptive conduit continues to the land surface. With 
regard to the dog-leg, the model report states in Section 6.4.5 (BSC 2004 [DIRS 170028]), as 
follows: 
 In the case of effusive flow, magma will continue along the trajectory of 
the original dike after intruding the drift complex. In the unlikely event 
that an existing joint at the drift periphery is invaded by magma, the flow 
will be interrupted by magma freezing long before it is able to reach the 
surface. 
 In the very unlikely event that magma encounters a pond of water in the 
drift, and that the mixing of magma and water is thorough enough to 
warrant a hydrovolcanic explosion next to an existing joint, a limited 
amount of magma is likely to vent to the surface. However, the volume of 
magma involved would be small (about 100 m3), and the new secondary 
dike would freeze as soon as the pressure from the explosion levels out. 
 The Woods et al. (2002 [DIRS 163662]) model of magma expansion into 
a drift greatly overestimates the violence of the encounter. Use of realistic 
initial conditions would preclude the formation of a shock wave for all but 
the most rapid magma ascent rates, while realistic boundary conditions 
would greatly reduce a shock wave, should any occur. In addition, the 
thermal aspects of the propagation of a thin secondary dike (i.e., magma 
freezing) were overlooked. 
Consequently, the dog-leg alternative conceptual model is not considered credible and is not 
further considered in the TSPA-LA. 
The Total System Performance Assessment (TSPA) Model for the License Application 
implements the eruptive model and its impact on the RMEI through the model for airborne 
transport (Section 6.4). For the volcanic eruption modeling case, a CDF is sampled to calculate 
the number of waste packages hit by eruptive conduits in a TSPA realization (BSC 2004 
[DIRS 170001] Section 6.4; BSC 2004 [DIRS 168504], Section 6.4). The CDF is based on a 
relationship between conduit areas and the fraction of the repository area occupied by waste 
packages. This relationship was used in conjunction with a distribution incorporating the 
variability in eruptive conduit diameters and the number of eruptive conduits that could intersect 
the repository. The CDF is used directly by the TSPA-LA for the volcanic eruption modeling 
case featuring the development of one or more volcanoes above the repository with one or more 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-71 November 2004 
conduits that intersect waste packages. The CDF provides the mass of waste available for 
incorporation with ash particles, which is required as an input for the ASHPLUME_DLL_LA 
V2.0 within the TSPA LA (BSC 2004 [DIRS 170026], Section 1.0 and 6.5.2). 
The mass of waste to be included in the eruptive event is calculated based on the proportion of 
CSNF to co-disposal waste packages in the repository and a sampled parameter that selects the 
number of waste packages affected by the eruptive event (BSC 2004 [DIRS 168504], 
Section 6.4.2.3). The CDF is explicitly implemented within TSPA-LA. Because the CDF is 
dependent on the underlying inputs, the underlying inputs and related FEPs are considered 
implicitly included in the TSPA-LA model. In addition to the mass of waste that might be 
included in an eruptive event, the particle sizes of the waste are important to subsequent eruption 
and dispersal calculations. Dispersal and Deposition of Tephra from a Potential Volcanic 
Eruption at Yucca Mountain, Nevada (BSC 2004 [DIRS 170026] Appendix H, Table H-2) 
indicates that mean particle size diameters vary from 0.002 cm for unaltered fuel to 0.0002 cm 
for corroded fuel. 
Once entrained and erupted, atmospheric transport of ash and radionuclides is modeled directly 
in TSPA-LA using the ASHPLUME_DLL_LA V2.0 as identified and discussed in Section 8.1 of 
BSC (2004 [DIRS 170026]). The ASHPLUME_DLL_LA V2.0 code implemented in the 
TSPA-LA is the same as the stand-alone ASHPLUME V2.0 code. In this FEP, 
ASHPLUME_DLL_LA V2.0 is used when discussing TSPA-LA implementation, and involves 
running multiple realizations with different sampled parameter inputs. The term, ASHPLUME 
model, is used when discussing generic features of the ASHPLUME V2.0 code for atmospheric 
dispersal and subsequent deposition of ash on the land surface from a potential volcanic eruption. 
Sections 6.5.1 and 6.5.2 of BSC (2004 [DIRS 170026]) describe the mathematical model and 
parameter inputs, respectively, used in the ASHPLUME model to calculate ash-and-waste 
dispersal in the wind. The TSPA-LA model stochastically samples the number of waste 
packages hit and the parameters used as input in each single ASHPLUME_DLL_LA V2.0 
realization. The ASHPLUME_DLL_LA V2.0 code is executed from within the TSPA_LA 
GoldSim model and ASHPLUME results are calculated and post-processed within GoldSim 
(BSC 2004 [DIRS 170026], Section 1.0). Consequently, the processes defined by the 
ASHPLUME mathematical model are considered as explicitly included in the TSPA-LA. 
In brief, for the volcanic eruption modeling case, the TSPA-LA model presumes that a 
hypothetical violent Strombolian eruption occurs vertically through a section of the repository, 
entraining radionuclide-bearing wastes in an ash plume. ASHPLUME_DLL_LA V2.0 is used 
within the TSPA GoldSim code to estimate radionuclide concentrations in contaminated ash 
falling on the ground surface at the location of the RMEI approximately 18 km south of the 
repository. The consequence (dose) of a volcanic eruption event at any given time is the sum of 
all of the probability-weighted consequences from all of the events that could have previously 
occurred. Within TSPA-LA, biosphere dose conversion factors calculated for the volcanic 
eruption modeling cases are used to calculate doses. This calculation is implemented within 
TSPA-LA by having the same volcanic eruption event occur at each time-step, 
probability-weighting the consequences, and then summing consequences from all time steps. 
The summation of events at a given time step is done within the GoldSim SoilExp_LA DLL as 
part of the source-term-multiplier calculations (BSC 2004 [DIRS 168504], Section 6.4.2.3). 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-72 November 2004 
Supporting Reports: Characterize Eruptive Processes at Yucca Mountain, Nevada, 
ANL-MGR-GS-000002 (BSC 2004 [DIRS 169980]) 
Number of Waste Packages Hit by Igneous Intrusion, 
ANL-MGR-GS-000003 (BSC 2004 [DIRS 170001]) 
Atmospheric Dispersal and Deposition of Tephra from a Potential 
Volcanic Eruption at Yucca Mountain, Nevada, 
MDL-MGR-GS-000002 (BSC 2004 [DIRS 170026]) 
Characterize Framework for Igneous Activity at Yucca Mountain, 
Nevada, ANL-MGR-GS-000001 (BSC 2004 [DIRS 169989]) 
6.2.2.7 Ashfall (1.2.04.07.0A) 
FEP Description: Finely divided waste particles may be carried up a volcanic vent 
and deposited on the land surface from an ash cloud. 
Screening Decision: Included 
Screening Argument: Not applicable. 
TSPA Disposition: Ashfall is included in the TSPA-LA and is addressed through the 
modeling of an eruptive event coupled with airborne transport and 
ash deposition. Consequences of the resulting ashfall are explicitly 
included in the TSPA-LA, and are appropriately weighted by the 
probability of occurrence of the event. Analysis model reports 
supporting the Screening Decision contain tables of included FEPs 
with pointers to more detailed background information on this FEP 
(BSC 2004 [DIRS 169980], Table 6-1; BSC 2004 [DIRS 170026], 
Table 6-1). 
The technical basis for inclusion of this FEP relies on the results of Characterize Framework for 
Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989]). Characterize 
Framework for Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989], 
Table 6-21) indicates that the annualized frequency of one or more eruptive centers occurring 
within the repository footprint as a result of an igneous intrusion is 1.3  10-8, which is slightly 
greater than the low probability threshold for FEPs screening (see Assumption 5.1 in Section 5). 
Additionally, the lateral extent of an ashfall from such an event is sufficient to reach the location 
of the RMEI, so the FEP has been included. 
The overall TSPA-LA approach for addressing igneous intrusion is outlined in Total System 
Performance Assessment-License Application Method and Approach (BSC 2003 [DIRS 166296], 
Section 8.1.2) and Total System Performance Assessment (TSPA) Model for the License 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-73 November 2004 
Application (BSC 2004 [DIRS 168504], Section 6.4). The two igneous events (with individual 
probabilities and consequences) modeled by the TSPA-LA are: 
 An igneous intrusion groundwater transport modeling case featuring the ascent of a 
basaltic dike or dike system (i.e., a set or swarm of multiple dikes comprising a single 
intrusive event) to the repository level where it intersects drifts (FEP 1.2.04.03.0A) 
 A volcanic eruption modeling case featuring the development of one or more volcanoes 
within the repository footprint, each with a conduit that may intersect waste packages 
(FEP 1.2.04.06.0A). 
As a consequence of the first event, which is non-eruptive, waste from breached packages may 
provide a source of radionuclides when groundwater moves through the damaged packages at 
some time in the future (igneous intrusion groundwater transport modeling case). The potential 
consequence of the second event (volcanic eruption modeling case) is that waste packages 
entrained within a conduit may be breached, releasing radionuclides in an erupting ash plume 
where they can be dispersed downwind to the RMEI. The location of the RMEI is assumed to be 
approximately 18 km south of the repository (10 CFR 63.312 and 10 CFR 63.302 
[DIRS 156605]). The Total System Performance Assessment (TSPA) Model for the License 
Application implements this airborne pathway and assesses its impact on the RMEI (BSC 2004 
[DIRS 168504], Section 6.4). The conceptual model for the eruptive process is discussed under 
FEP 1.2.04.06.0A (Eruptive conduit to surface intersects repository). The following discussion 
is focused on the eruption of an ash-waste mixture into the atmosphere and subsequent transport 
and deposition. 
The analysis report, Characterize Eruptive Processes at Yucca Mountain, Nevada (BSC 2004 
[DIRS 169980]) is based on the observed characteristics of past basaltic eruptions in the Yucca 
Mountain region and other analogous eruptions. This analysis report includes the results of field 
investigations dealing with physical volcanology and ash and tephra distribution and includes the 
conceptual models for eruptive processes. This information is used to develop parameter value 
distributions appropriate for analysis of the consequences of volcanic eruptions through a 
proposed repository at Yucca Mountain, Nevada. The parameters developed (BSC 2004 
[DIRS 169980], Table 7-1) and related to this FEP include the following: 
 Eruptive power 
 Eruption duration for formation of an entire volcano 
 Duration of a single explosive phase constituting a violent Strombolian eruptive phase 
 Tephra fall or ash volume 
 Mean particle size erupted during violent Strombolian phases 
 Standard deviation of particle size distribution for a given mean 
 Clast characteristics 
 Density of erupted particles 
 Tephra deposit density. 
The results of the analysis report (BSC 2004 [DIRS 169980]) do not directly feed to the 
TSPA-LA model. Some results provide recommended inputs to the report, Atmospheric 
Dispersal and Deposition of Tephra from a Potential Volcanic Eruption at Yucca Mountain, 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-74 November 2004 
Nevada (BSC 2004 [DIRS 170026], Table 6-3). Many other outputs in Table 7-1 (BSC 2004 
[DIRS 169980]) support analyses resulting in parameter distributions that indirectly or directly 
feed the TSPA-LA (e.g., conduit diameter and waste packages hit CDF) or support the 
conceptual model implemented in the TSPA-LA (e.g., magma chemistry) (BSC 2004 
[DIRS 169980]). Thus, these inputs are implicitly included in the TSPA-LA model. 
The model report, Atmospheric Dispersal and Deposition of Tephra from a Potential Volcanic 
Eruption at Yucca Mountain, Nevada (BSC 2004 [DIRS 170026], Table 6-3), lists parameters 
used to implement this FEP within the TSPA-LA. Those parameters developed within the 
analysis report, Characterize Eruptive Processes at Yucca Mountain, Nevada (BSC 2004 
[DIRS 169980]), include: 
 Mean ash particle diameter 
 Ash particle diameter standard deviation for particle size distribution 
 Ash particle shape factor 
 Ash particle density at minimum, and a maximum, particle size 
 Log ash particle size for ash particle density at minimum, and at maximum, particle 
density 
 Eruptive power and eruption duration. 
The technical basis for parameters developed within the Atmospheric Dispersal and Deposition 
of Tephra from a Potential Volcanic Eruption at Yucca Mountain, Nevada (BSC 2004 
[DIRS 170026]) model report include, but are not limited to, the following (BSC 2004 
[DIRS 170026], Section 6.5.2): 
 Column diffusion constant, which affects the distribution of particles within the ash 
column 
 Waste incorporation ratio, a mathematical construct used to transport a density-corrected 
combined ash and fuel particle 
 Waste particle size (min, max, mode) 
 Maximum particle diameter for transport 
 Wind speed and wind direction, based on site-specific data collected over the 
appropriate range of ash column height 
 Initial rise velocity of plume 
 Eddy diffusivity constant, with the simplification made that particle diffusion time 
equals particle fall time. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-75 November 2004 
Atmospheric transport of the ash-waste mixture is modeled directly in TSPA-LA using the 
ASHPLUME_DLL_LA V2.0, as identified and discussed in Section 8.1 of BSC (2004 
[DIRS 170026]). The ASHPLUME_DLL_LA V2.0 code implemented in the TSPA-LA is the 
same as the stand-alone ASHPLUME V2.0 code. In this FEP, ASHPLUME_DLL_LA V2.0 is 
used when discussing TSPA implementation. The TSPA-LA model stochastically samples 
different parameters used as inputs for different ASHPLUME_DLL_LA V2.0 realizations. The 
term, ASHPLUME model, is used when discussing generic features of the ASHPLUME V2.0 
model for atmospheric dispersal and subsequent deposition of ash on the land surface from a 
potential volcanic eruption. 
In brief, for the volcanic eruption modeling case, the TSPA-LA model presumes that a 
hypothetical violent Strombolian eruption occurs vertically through a section of the repository, 
entraining radionuclide-bearing wastes in an ash plume. ASHPLUME_DLL_LA V2.0 models 
dispersal and deposition of the contaminated ash downwind on the ground surface. The 
ASHPLUME_DLL_LA V2.0 is used within the TSPA-LA model to estimate radionuclide 
concentrations in contaminated ash falling at the location of the RMEI, approximately 18 km 
south of the repository. 
The ASHPLUME_DLL_LA V2.0 code is executed from within the TSPA-LA GoldSim model 
and ASHPLUME results are calculated and post-processed within GoldSim. The wind speed 
and direction that result in atmospheric transport of the erupted material are represented in 
ASHPLUME_DLL_LA V2.0 within the TSPA-LA in terms of cumulative distribution 
(BSC 2004 [DIRS 170026], Section 6.5.2). These cumulative distribution functions are specified 
for 1 km height increments between 0 km and 13 km above the mountain. 
Sections 6.5.1 and 6.5.2 of BSC (2004 [DIRS 170026]) describe the mathematical model and 
parameter inputs, respectively, used in the ASHPLUME model to calculate ash-and-waste 
dispersal in the wind. The TSPA-LA model stochastically samples the number of waste 
packages hit and the parameters used as input in each single ASHPLUME_DLL_LA V2.0 
realization. The ASHPLUME model specifically addresses the issues of waste incorporation 
into the volcanic ash, the extent of the ash plume into the atmosphere, the atmospheric transport 
of the ash and entrained waste, and the thickness of ash deposits in the vicinity of the RMEI. 
GoldSim first samples the inputs that are probability distributions and then passes this input to 
the ASHPLUME_DLL_LA V2.0. The ASHPLUME_DLL_LA V2.0 code then calculates the 
waste and ash deposition results (g/cm2) at the RMEI location. The TSPA-LA model then 
converts the waste deposition at the RMEI location back to the masses of the individual 
radionuclide species and allows for radioactive decay (BSC 2004 [DIRS 168504], Section 6.4.2). 
The ASHPLUME model and supporting parameters are explicitly included in the TSPA-LA 
model. 
Supporting Reports: Characterize Eruptive Processes at Yucca Mountain, Nevada 
ANL-MGR-GS-000002 (BSC 2004 [DIRS 169980]) 
Atmospheric Dispersal and Deposition of Tephra from a Potential 
Volcanic Eruption at Yucca Mountain, Nevada 
MDL-MGR-GS-000002 (BSC 2004 [DIRS 170026]) 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-76 November 2004 
6.2.2.8 Ash Redistribution via Soil and Sediment Transport (1.2.04.07.0C) 
FEP Description: Following deposition of contaminated ash on the surface, ash 
deposits may be redistributed on the surface via eolian and fluvial 
processes. 
Screening Decision: Included 
Screening Argument: Not Applicable 
TSPA Disposition: Ashfall events and processes are directly addressed in Atmospheric 
Dispersal and Deposition of Tephra from a Potential Volcanic 
Eruption at Yucca Mountain, Nevada (BSC 2004 [DIRS 170026]). 
The TSPA-LA includes consideration of exposure from 
redistributed ash. Analysis model reports supporting the Screening 
Decision contain tables of included FEPs with pointers to more 
detailed background information on this FEP (BSC 2004 
[DIRS 170026], Table 6-1; BSC 2004 [DIRS 169980], Table 6-1). 
The technical basis for inclusion of this FEP relies on the results of Characterize Framework for 
Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989]). Characterize 
Framework for Igneous Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989], 
Table 6-1) indicates that the annualized frequency of one or more eruptive centers occurring 
within the repository footprint as a result of an igneous intrusion is 1.3  10-8 (see 
Assumption 5.1 in Section 5), which is slightly greater than the low probability threshold for 
FEPs screening. Additionally, the lateral extent of an ashfall from such an event is sufficient to 
reach the location of the RMEI. Ash that falls at the location of the RMEI and between that 
location and the eruptive vent, is subject to redistribution on the surface by eolian and fluvial 
processes. In other words, tephra that did not originally fall at the RMEI location could be 
redistributed to the RMEI location by sedimentary processes, therefore this FEP has been 
included. 
For the volcanic eruption modeling case, the TSPA-LA presumes that a hypothetical violent 
Strombolian eruption occurs through a section of the repository, entraining radionuclide-bearing 
wastes in an ash plume that disperses downwind and deposits contaminated ash on the ground 
surface (BSC 2004 [DIRS 170026], Section 6.5). Using the ASHPLUME_DLL_LA V2.0 code, 
the TSPA-LA model estimates radionuclide concentrations in contaminated ash falling at the 
location of the RMEI, approximately 18 km south of the repository (10 CFR 63.312 and 
10 CFR 63.302 [DIRS 156605]). 
The ASHPLUME_DLL_LA V2.0 code implemented in the TSPA-LA is the same as the 
stand-alone ASHPLUME V2.0 code. In this FEP, ASHPLUME_DLL_LA V2.0 is used when 
discussing TSPA implementation, which involves multiple realizations with different sampled 
parameter inputs. The term ASHPLUME model is used when referring to the results of a 
separate 100-realization model study that is used in the redistribution abstraction, and refers to 
used of mean primary and geometric mean concentrations (see Table 6-3). 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-77 November 2004 
After deposition of the tephra sheet, the tephra and waste are available for redistribution by 
fluvial and eolian processes that could erode, transport, mix, and redeposit the tephra (BSC 2004 
[DIRS 170026], Section 8.1). The ash redistribution calculations for a probability-weighted 
volcanic event are performed within TSPA-LA using the SoilExp_LA DLL (BSC 2003 
[DIRS 166296], Section 2.1). The TSPA-LA approach for calculating exposure through the use 
of volcanic-specific biosphere dose conversion factors is outlined in Total System Performance 
Assessment-License Application Method and Approach (BSC 2003 [DIRS 166296], 
Section 8.1.2). Total System Performance Assessment (TSPA) Model for the License Application 
calculates dose from exposure due to inhalation, ingestion, and external exposure and its impact 
on the RMEI (BSC 2004 [DIRS 168504], Section 6.4.2.3). To determine dose, biosphere dose 
conversion factors are applied as developed according to the biosphere model component. 
Within TSPA-LA, there are two possible outcomes of an eruption through the repository and the 
subsequent redistribution of the ash: 
 Outcome 1 addresses primary ash fall on the RMEI location and local redistribution of 
the ash 
 Outcome 2 addresses primary ash fall in the upper Fortymile Wash drainage basin and 
subsequent redistribution of that ash to the location of the RMEI. 
The Soil_Exp DLL implements Table 6-3 below as the abstraction within the TSPA-LA 
(BSC 2004 [DIRS 168504], Sections 6.4.2.3). 
In Outcome 1, direct deposition of ash and waste occurs in the vicinity of the RMEI and 
represents the greatest degree of exposure from an eruptive process (BSC 2004 [DIRS 170026], 
Sections 6.3.2 and 6.6.3). All other mechanisms (e.g., eolian or fluvial processes) allow for 
mixing and dilution of the ash and waste through distance and with time. Presumably, a volume 
of transported sediment with a diluted ash component would have less impact on the RMEI than 
would a primary ash fall that fell directly on the RMEI (BSC 2004 [DIRS 170026], 
Section 5.1.3). 
In Outcome 2, direct deposition of ash and waste occurs in the upper Fortymile Wash drainage 
basin, outside the vicinity of the RMEI. Tephra sheet deposition may occur in any direction, 
depending on the sampled wind direction. However, other tephra-sheet orientations either 
eliminate ash from reaching the RMEI location, or reduce the available volume of ash to be 
redistributed to the RMEI location (BSC 2004 [DIRS 170026], Sections 5.1.3 and 6.3.2). For the 
TSPA-LA, the tephra sheet is assumed to be deposited within the Fortymile Wash drainage basin 
(consistent with prevailing southwesterly winds), making ash available upstream from the RMEI 
location in all realizations. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-78 November 2004 
Both Outcomes 1 and 2, presented in Table 6-3, explicitly consider two different geomorphic 
areas that respond differently to ash fall and redistribution (BSC 2004 [DIRS 170026], 
Sections 6.7.2.3 and 6.7.2.4): 
 On interchannel divides, the dominant geomorphic process is presumed to be erosion, 
resulting in ash removal 
 Within the channels, sediment transport processes will move contaminated ash through 
the region in response to storm events. 
In Outcome 1, on interchannel divides, ash-layer (tephra) thickness and areal waste concentration 
is calculated by ASHPLUME_DLL_LA V2.0 in the TSPA_LA model. Ash removal is assumed 
to occur at a rate uniformly distributed between 0.02 to 0.04 cm/yr. After ash removal, residual 
contamination is assumed to remain within a 9-cm contaminated soil layer beneath the initial 
ash, as explained in Table 6-3. In Outcome 2, where deposition would occur away from the 
RMEI, areal waste concentration on interchannel divides is derived from the separate 
ASHPLUME model results, discussed above, with wind direction fixed southward (see 
Table 6-3). Possible contamination by eolian processes or major flood events is approximated 
by a 1 to 2 cm (uniform distribution) layer with 1/100th of the initial mean primary waste 
concentration derived from the separate ASHPLUME calculation. The layer is assumed to 
remain indefinitely. 
Table 6-3. Ash Redistribution Factors for the TSPA Model 
Interchannel Divide Distributary Channels 
AREAL 
WEIGHT 0.82 0.18 
Outcome 1 
Primary 
tephra (ash 
fall) in the 
vicinity of 
the RMEI 
location. 
Initial Ash-layer (tephra) thickness 
calculated by ASHPLUME_DLL_LA in the 
TSPA model. 
Initial waste areal concentration calculated 
in TSPA for the ash layer at the location of 
the RMEI. 
Ash removal 
At a rate uniformly distributed between 
0.02 to 0.04 cm/yr. 
Residual 
9-cm contaminated soil layer beneath 
initial ash. Volumetric concentration of the 
waste (as specified in Table 6-5 from 
BSC 2004 [DIRS 170026]) in this layer 
decreases linearly from the initial value 
calculated in the ash to 1/100th of that 
value at 9 cm. This layer is removed at the 
same rate as the initial ash layer, 
consistent with 137Cs observations. The 
linear volumetric concentration decrease is 
conservative with respect to the 
exponential decrease observed for 137Cs. 
Below the 9-cm layer is an additional 1 to 2 
cm (uniform distribution) layer with 1/100th 
of the initial volumetric concentration. 
Assumed to remain indefinitely. 
Represents infiltration from initial ash layer 
before removal. 
Initial condition 
Initial ash-layer thickness: uniform distribution from 1 to 
15 cm, or the initial ash layer thickness calculated for the 
divide areas in the TSPA model, whichever is greater. 
Initial waste concentration: mean primary waste 
concentration (as specified in Table 6-5 from BSC 2004 
[DIRS 170026]), except for realizations in which the ash 
thickness calculated in the TSPA is greater than the 
thickness sampled from the 1 to 15 cm uniform 
distribution; in those cases, use the waste volumetric 
concentration calculated in TSPA for the ash layer at the 
location of the RMEI. 
Ash removal 
Volumetric concentration of waste in the ash layer 
decreases linearly from its initial volumetric concentration 
to 1/100th of its initial volumetric concentration within a 
time period uniformly distributed between 100 and 1,000 
years. This decrease in volumetric concentration 
represents dilution during removal and replacement of 
the initial sediment. 
Residual outcome 
After removal of the initial volumetric concentration, a 
layer with the same initial thickness but with 1/100th of 
the initial volumetric concentration is assumed to remain 
indefinitely. 
This residual layer represents lower levels of 
contamination that may be brought down the wash or 
exposed from underlying soil. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-79 November 2004 
Table 6-3. Ash Redistribution Factors for the TSPA Model (Continued) 
Interchannel Divide Distributary Channels 
AREAL WEIGHT 0.82 0.18 
Outcome 2 
No primary tephra fall 
on, or near the RMEI 
location. Primary 
tephra deposition in 
upper Fortymile Wash 
drainage basin. 
Possible contamination by eolian 
processes or major flood events is 
approximated by a 1 to 2 cm 
(uniform distribution) layer with 
1/100th of the initial mean primary 
waste concentration (as specified in 
Table 6-5 from BSC 2004 
[DIRS 170026]), from the 18-km 
ASHPLUME calculations and is 
assumed to remain indefinitely. 
Initial condition 
Initial ash-layer thickness: uniform distribution from 
1 to 15 cm. 
Initial waste concentration: geometric mean 18-km 
ASHPLUME volumetric concentration. 
Ash removal 
Volumetric concentration of waste in the ash layer 
decreases linearly from its initial volumetric 
concentration to 1/100th of its initial volumetric 
concentration within a time period uniformly 
distributed between 100 and 1,000 years. This 
decrease in volumetric concentration represents 
dilution during removal and replacement of the 
initial sediment. 
Residual outcome 
After removal of the initial volumetric concentration, 
a layer with the same initial thickness, but with 
1/100th of the initial volumetric concentration is 
assumed to remain indefinitely. 
This residual layer represents lower levels of 
contamination that may be brought down the wash 
or exposed from underlying soil. 
Source: BSC 2004 [DIRS 170026], Section 6.7.2.2 and Table 6-5. 
Within distributary channels, Outcomes 1 and 2 are treated similarly. The initial ash-layer 
thickness is derived from a uniform distribution from 1 to 15 cm. The initial areal ash 
concentrations are generally derived from the separate ASHPLUME model results with wind 
direction fixed southward, as described above and in Table 6-3. The volumetric concentration of 
waste in the ash layer decreases linearly from its initial volumetric concentration to 1/100th of its 
initial volumetric concentration within a time period uniformly distributed between 100 and 
1,000 years. Eventually, within the channels, the watershed would be depleted of contaminated 
ash, but the duration for this process is unknown. Mixing processes will also dilute the ash with 
uncontaminated sediment, but existing data are insufficient to quantify that dilution. Given these 
uncertainties, the TSPA-LA assumes a layer to remain indefinitely with the sampled initial 
thickness but with 1/100th of the initial volumetric concentration derived from the separate 
ASHPLUME calculation (BSC 2004 [DIRS 170026], Sections 1.3.2 and 6.7.2.4). 
The analysis and model reports Characterize Eruptive Processes at Yucca Mountain, Nevada 
(BSC 2004 [DIRS 169980], Section 6.5) and Atmospheric Dispersal and Deposition of Tephra 
from a Potential Volcanic Eruption at Yucca Mountain, Nevada (BSC 2004 [DIRS 170026]) 
include the results of field investigations and present the detailed conceptual and technical basis 
for the ash redistribution model that is then abstracted as described here and implemented within 
TSPA-LA. 
The TSPA-LA model performs calculations for the ash redistribution model based on the results 
of an ASHPLUME_DLL_LA V2.0 calculation for a particular realization (see Section 6.2.2.7). 
The SoilExp_LA DLL within GoldSim defines such parameters as mean ash and waste 
concentrations; percentage of the initial volumetric concentration, which remains indefinitely in 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-80 November 2004 
the soil; areal weight fraction of the interchannel divides and the distributary channels; ash 
removal rate; initial and residual ash thicknesses; ash removal time; and biosphere model 
component inputs (BSC 2004 [DIRS 166296], Section 2.1; BSC 2004 [DIRS 170026], 
Section 6.7.2; BSC 2004 [DIRS 168504], Section 6.4.2.3). SoilExp_LA performs redistribution 
calculations for each TSPA Model time step within a realization with the probability-weighted 
consequence equaling the sum of all time steps in each realization (see Section 6.2.2.6). 
Supporting Reports: Characterize Eruptive Processes at Yucca Mountain, Nevada 
ANL-MGR-GS-000002 (BSC 2004 [DIRS 169980]) 
Atmospheric Dispersal and Deposition of Tephra from a Potential 
Volcanic Eruption at Yucca Mountain, Nevada 
MDL-MGR-GS-000002 (BSC 2004 [DIRS 170026]) 
6.2.2.9 Hydrologic Response to Igneous Activity (1.2.10.02.0A) 
FEP Description: Igneous activity includes magmatic intrusions, which may alter 
groundwater flow pathways, and thermal effects that may heat up 
groundwater and rock. Igneous activity may change the 
groundwater flow directions, water level, water chemistry, and 
temperature. Eruptive and extrusive phases may change the 
topography, surface drainage patterns, and surface soil conditions. 
This may affect infiltration rates and locations. 
Screening Decision: Excluded - Low Consequence 
Screening Argument: Igneous intrusion into the repository (i.e., igneous activity) could 
potentially alter the hydrologic characteristics of the site and thereby 
affect flow-and-transport characteristics and release to the 
accessible environment and exposure. However, the orientation of 
the dikes and the limited scale of a few meters indicate that the 
hydrologic response would be of low consequence. 
The technical basis for exclusion of this FEP relies on a variety of information including 
observed phenomena at analogue sites, analysis of effects on ground water flow pathways, and 
information on thermal effects on rock properties. These are discussed in the following 
paragraphs. The reader should keep in mind that not all the studies discussed here were 
preformed for the purpose of assessing igneous impacts on hydrology, and in several instances 
inferences are drawn. For example, if thermal effects, as indicated by mineralogic changes, are 
confined to a narrow zone around an intruded dike, it is inferred that any resulting changes in 
water chemistry and permeability are also confined to that narrow zone. 
Observed Phenomena at Analogue SitesAn appropriate analogue for understanding the 
characteristics of a volcanic event at Yucca Mountain is the Paiute Ridge intrusive/extrusive 
center (Byers and Barnes 1967 [DIRS 101859]) on the northeastern margin of the Nevada Test 
Site. The Paiute Ridge center is a small-volume Miocene volcanic center comparable in volume 
and composition to Quaternary volcanoes near Yucca Mountain (BSC 2004 [DIRS 169989], 
Section 6.3.2.1). Paleomagnetic, geochronologic, and geochemical data indicate that the entire 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-81 November 2004 
intrusive/extrusive complex formed during a brief magmatic pulse and thus represents a single 
volcanic event. The vents and associated dike system formed within a north-northwest-trending 
extensional graben and there are excellent exposures of a variety of system depths. This includes 
remnants of surface lava flows, volcanic conduits, and dikes and sills intruded into tuff country 
rock at depths of up to 300 m. There is evidence of shallow structural control of dike 
emplacement at Paiute Ridge, including dike emplacement along fault planes (Byers and Barnes 
1967 [DIRS 101859]). Dike lengths at Paiute Ridge range from less than 1 km to 5 km, 
comparable to the range estimated for post-Miocene volcanism near Yucca Mountain. 
Carter Krogh and Valentine (1996 [DIRS 160928], pp. 7 and 8) described the margins of the 
Paiute Ridge (PR) dike complex as follows: 
PR dike contains ubiquitous near-vertical joints that result in a pervasive platy 
texture with plates parallel to the dike-host contact. Conversely, with the 
exception of local cooling joints in fused wall rock (extending 10 cm to 20 cm 
into the wall rock, perpendicular to the dike margin), joints are never visible in the 
host rock along the length of the dike. The contact between basalt and the tuff 
host rock is consistently smooth and shows no brecciation. Along strike at this 
contact, the tuff host rock is fused or welded to varying degrees: in places the tuff 
is completely welded and forms black vitrophyre that grades rapidly away from 
the contact, over a distance of ca 20 cm to 100 cm, into nonwelded tuff that is 
apparently unaffected by the dike. In other places the tuff is only partly welded at 
the contact and black fiamme are elongated parallel to the contact. We infer that 
this contact welding is the combined result of heat from the dike and 
compressive stress exerted by the flowing magma on the wall rocks. Welded host 
rock commonly contains vesicles that are elongated vertically and parallel to the 
margin. In some places, welded tuff coats the basalt and displays rills or elongate 
smooth ridges (flutes). Most rills plunge nearly vertically, however, a 
sub-horizontal rill is present in the central part of the dike. At the dike tip, 
exposed at Slanted Buttes, scoria patches crop out near the dike-host contact. 
The two eastern dikes, M and E  show geometries and textures similar to those 
of PR; however, M dike is much shorter and does not feed a sill, and E dike was 
emplaced closest to the paleosurface and feeds two sills. M dike  visibly 
occupies a normal fault, oriented N40 W, 61 E,  Its host rocks are only 
Tertiary tuffs, which show no brecciation or jointing near the dike contact  
Texture within the dike is characterized by a vertical platy fabric that parallels the 
dike margins. E dike is the eastern-most dike studied within the graben. Near the 
neck, the dike visibly occupies a NNW-trending, steeply E-dipping normal fault 
that displaces bedded tuffs 3.5 m and does not cut the dike The texture of 
E dike is characterized by the pervasive vertical platy fabric common to M and 
PR dikes. Adjacent host tuffs are not jointed nor brecciated, except for local 
vertical jointing of the Rainier Mesa tuff, which is intruded by the dike at its 
shallowest level. The contact of the dike and host tuff is preserved in places and 
varies from partly to completely welded in the same manner as described above 
for the PR dike. Where complete welding has occurred, vesicles are vertical and 
parallel the dike margin. Contact welding of the host tuffs formed oblate fiamme 

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ANL-WIS-MD-000005 REV 02 6-82 November 2004 
that parallel the dike-host contact. Visible thermal effects on the wall rocks 
disappear within 1-m of the dike margin. 
This description suggests that zones of change in rock properties (i.e., formation of vitrophyres 
and/or various degrees of welding of the host rock and formation of fiamme, which are flattened 
glassy inclusions) are limited to between a few tens of centimeters, to at most a meter 
perpendicular to the dike. Other features such as the platy texture along the dike margins and 
vesicles in the welded tuff are oriented parallel to the dike margins. This orientation suggests 
that the primary direction of increased or decreased permeability (if any) is parallel with the dike 
margins. 
Effects on Groundwater Flow PathwaysThe following discussion on the potential for an 
intrusion to effect groundwater flow pathways includes an evaluation of the orientation of a 
possible future dike because orientation could affect the consequences of an intrusion. Most 
researchers conclude that after ascending dikes enter the shallow upper crust, their location and 
orientation are influenced by the orientation of the local stress field and the presence of faults 
that may locally control alignment. The evidence cited for this conclusion, in addition to the 
interaction of faults and dikes at the Paiute Ridge center described above, includes several 
northeast-oriented vent alignments in the Yucca Mountain region and the association of eruptive 
centers with known or inferred faults (CRWMS M&O 1996 [DIRS 100116], Appendix E, 
p. AM-4; Connor et al. 1996 [DIRS 135969], p. 78). 
The results of the PVHA are summarized in the analysis report Characterize Framework for Igneous 
Activity at Yucca Mountain, Nevada (BSC 2004 [DIRS 169989]), which presents probability 
distributions for the length and orientation of possible future volcanic dikes near the repository. 
The aggregate dike-length distribution derived from the PVHA has a mean value of 4.0 km, and 
the most commonly assigned dike orientation centers on N30E (BSC 2004 [DIRS 169989], 
Section 6.3.2). The anisotropic transmissivity observed in the SZ in the Yucca Mountain region 
has a maximum principal transmissivity direction of approximately N15E (BSC 2004 
[DIRS 170042], Section 6.5.2.10), which is generally consistent with the fault and fracture 
orientations. A corroborative analysis by Ferrill et al. (1999 [DIRS 118941], p. 1) indicated a 
N30E orientation. A north-to-northeast orientation parallels or sub-parallels the faults and 
fractures active in the present-day in situ stress field. Dike features that may form in the future, 
such as the platy texture and welded surfaces that could affect the permeability, will parallel the 
dike orientation, and will likely be aligned in a north-to-northeast orientation. 
This parallel to subparallel orientation of dikes and maximum principal transmissivity, coupled 
with the expected limited affected volume of material around the dikes, indicates that dikes, even 
if differing in permeability, will not significantly affect groundwater flow patterns at the 
mountain scale. By way of corroboration, an early analysis of the effect of a dike on flow in the 
SZ was conducted and documented in Chapter 10 of the TSPA-VA (CRWMS M&O 1998 
[DIRS 100369], Section 10.4.4). The corroborative analysis suggested that there would be 
negligible impact for a dike oriented north to northeast. The analysis included a variety of dike 
lengths and locations respective to the repository area. Additionally, the occurrence of such a 
change is conditional on a low probability event of an igneous intrusion. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-83 November 2004 
The report Synthesis of Volcanism Studies for the Yucca Mountain Site Characterization Project 
(CRWMS M&O 1998 [DIRS 105347], p. 5-56) mentions the possibility of perched water 
forming near low-permeability intrusive bodies and a concern regarding the potential for a dike 
to provide a barrier to flow and/or cause impoundments. Because of the parallel, to subparallel 
orientation of dikes with the existing orientation of the anisotropic maximum horizontal 
permeability in the SZ, a dike would not form a barrier or impoundment that would have any 
significant effect on flow in the SZ. By way of corroborative information, for a dike initially 
intruding into the SZ, Rojstaczer (1991 [DIRS 163416], Abstract) indicates a possible rise in the 
water table of only a few tens of meters. In the UZ, the primary direction of groundwater flow is 
vertically downward through the fractures. Because the joints on a dike margin would be 
near-vertical, the formation of a significant perched water zone would be dependant on the 
formation of a sill. The potential impact of sill formation is addressed in the FEP 1.2.04.03.0A 
(Igneous intrusion into repository). The formation of a perched water zone is addressed in the 
FEP 2.2.07.07.0A (Perched water develops). Drainage from a perched water zone is addressed 
in FEP 2.2.06.03.0A (Seismic activity alters perched water zone). 
Relative to groundwater flow paths that might be impacted in or near the repository as a result of 
post-intrusion in-drift conditions, the TSPA-LA addresses these potential conditions through the 
assumption that the permeability of any contact metamorphic aureole surrounding the intruded 
drifts is as great as that of the bulk host rock (see BSC 2004 [DIRS 170028], Section 5.4.1). The 
basalt is assumed to fracture during cooling so that it provides no barrier to flow from the 
formation. Therefore, the seepage abstraction changes, in the case of an igneous event, because 
there is probably no capillary barrier to seepage in basalt-filled drifts (BSC 2004 [DIRS 169131], 
Section 6.5.1.7). After post-intrusive magma cooling, seepage water is expected to flow through 
the contact metamorphic aureole and react with the basalt in the intruded emplacement drifts. 
The geochemical interactions of the seepage water and rock and the resulting hydrochemistry are 
addressed in FEP 1.2.04.04.0B in Section 6.2.2.4 of this report. 
Potential Thermal and Geochemical EffectsWith regard to possible geochemical changes and 
based on studies of natural-analogue sites, Synthesis of Volcanism Studies for the Yucca 
Mountain Site Characterization Project (CRWMS M&O 1998 [DIRS 105347], pp. 5-1 and 5-2) 
states that for shallow, small-volume basaltic intrusions, the chemical and mineralogical studies 
of host tuffs indicate that alteration is limited to within a few tens of meters of the intrusion. 
More specifically, from a study of the Paiute Ridge analogue site, there is no indication of 
extensive hydrothermal circulation and alteration, brecciation, and deformation related to 
magmatic intrusion, or vapor-phase recrystallization during the magmatic intrusions into the 
vitric and zeolitized tuffs (CRWMS M&O 1998 [DIRS 105347], p. 5-42). The analogue studies 
show that alteration is quite limited and is typically only found within 5 to 10 m of intrusions 
(CRWMS M&O 1998 [DIRS 105347], p. 5-41). At the Paiute Ridge center, low-temperature 
secondary minerals persist near the contact with intrusions (CRWMS M&O 1998 
[DIRS 105347], p. 5-46). This persistence suggests that little destruction of pre-existing sorptive 
minerals is expected. Given the limited area of alteration and the consequent change of rock 
properties around the intrusion, the effect of alteration is minimal and alteration does not provide 
a mechanism to significantly change the dose. Therefore, this aspect of this FEP is excluded 
from the TSPA-LA based on low consequence. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 6-84 November 2004 
Potential for Development of a Hydrothermal SystemSynthesis of Volcanism Studies for the 
Yucca Mountain Site Characterization Project (CRWMS M&O 1998 [DIRS 105347], p. 5-86) 
considered the effects of hydrothermal systems (the heating up of groundwater and rock) 
resulting from igneous intrusions. Findings from the Paiute Ridge analogue site indicate that, 
the occurrence of clinoptilolite and opal also suggests that thermal transfer into the adjacent 
country rock was minimal (CRWMS M&O 1998 [DIRS 105347], p. 5-57). Findings from the 
Grants Ridge analogue site in New Mexico suggest the absence of a hydrothermal system at that 
location (CRWMS M&O 1998 [DIRS 105347], p. 5-74). Further, the study concluded that, an 
intrusion at Yucca Mountain would not result in large amounts of hydrothermally driven mass 
transfer (CRWMS M&O 1998 [DIRS 105347], p. 5-74). Consequently, the development of 
hydrothermal systems from igneous activity is excluded from the TSPA-LA based on low 
consequence due to their limited size relative to the repository footprint. 
Potential Topographic and Surface Effects Following an EruptionThere is a potential for 
igneous activity (primarily via eruption or effusive flow) to change surface topography, and 
subsequently affect drainage and infiltration. The effects could hypothetically result in 
temporary damming of a drainage intersected by a lava flow at the surface or from the sloughing 
of ash or soil materials from hill slopes into drainages. The steep topographic gradients at Yucca 
Mountain above the repository and the limited extent of effusive flow from small-scale 
volcanoes, such as Lathrop Wells, would limit the consequences of any such topographic 
changes. The net result through time would likely resemble something akin to the Lathrop Wells 
volcano, where drainage patterns readjust and re-equilibrate to match the change in conditions, 
resulting in relocation of the drainage. This, rather than any significant ponding or increased 
infiltration effects. Therefore the topographic aspect of the FEP is excluded based on low 
consequence. FEP 1.2.04.07.0C (Section 6.2.2.8) discusses assumptions regarding infiltration of 
radionuclides into underlying soil following ashfall and subsequent redistribution. 
SummaryThe parallel orientation of potential future dikes with the direction of maximum 
transmissivity in the SZ, coupled with the limited volume of the dike and adjacent affected rock, 
indicates that dikes (even if differing in permeability from the host rock) will not significantly 
affect groundwater-flow patterns or water levels. Because there would be no significant change 
to the flow system, hydrologic response to igneous activity does not provide a mechanism for 
significantly changing dose. Given the limited area of any thermal or geochemical alteration, 
and the consequent change of rock properties around an intrusion, the effect of alteration would 
be minimal and alteration would not provide a mechanism to significantly change the dose. The 
potential development of a hydrothermal system from igneous activity is not likely based on 
analogue studies and would be of low consequence due to its limited size relative to the 
repository footprint. Any possible changes to topography and soils from extrusive activity are 
also of low consequence. Consequently, the FEP Hydrologic response to igneous activity is 
excluded from the TSPA-LA based on low consequence. 
TSPA Disposition: Not Applicable 
Supporting Reports: Not Applicable 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 7-1 November 2004 
7. CONCLUSIONS 
Table 7-1 summarizes the disruptive events FEP-screening decisions and the basis for the 
decisions. This analysis report may be affected by technical product input information that 
requires confirmation. Any changes to the document that are required because of completing the 
confirmation activities will be reflected in subsequent revisions. The quality status of the 
technical product input may be confirmed by review of the FEP database. 
Table 7-1. Summary of Disruptive Events FEP Screening Decisions 
TSPA-LA FEP 
Number TSPA-LA FEP Name 
Screening Decision 
and Basis 
Section Where 
Addressed 
1.2.01.01.0A Tectonic activity-large scale Excluded - Low 
Consequence 
6.2.1.1 
1.2.02.03.0A Fault displacement damages EBS components Included 6.2.1.2 
1.2.03.02.0A Seismic ground motion damages EBS components Included 6.2.1.3 
1.2.03.02.0B Seismic-induced rockfall damages EBS components Excluded - Low 
Consequence 
6.2.1.4 
1.2.03.02.0C Seismic-induced drift collapse damages EBS components Excluded - Low 
Consequence 
6.2.1.5 
1.2.03.02.0D Seismic-induced drift collapse alters in-drift 
thermohydrology 
Included 6.2.1.6 
1.2.03.03.0A Seismicity associated with igneous activity Included 6.2.1.7 
1.2.04.02.0A Igneous activity changes rock properties Excluded - Low 
Consequence 
6.2.2.1 
1.2.04.03.0A Igneous intrusion into repository Included 6.2.2.2 
1.2.04.04.0A Igneous intrusion interacts with EBS components Included 6.2.2.3 
1.2.04.04.0B Chemical effects of magma and magmatic volatiles Included 6.2.2.4 
1.2.04.05.0A Magma or pyroclastic base surge transports waste Excluded - Low 
Consequence 
6.2.2.5 
1.2.04.06.0A Eruptive conduit to surface intersects repository Included 6.2.2.6 
1.2.04.07.0A Ashfall Included 6.2.2.7 
1.2.04.07.0C Ash redistribution via soil and sediment transport Included 6.2.2.8 
1.2.10.01.0A Hydrologic response to seismic activity Excluded - Low 
Consequence 
6.2.1.8 
1.2.10.02.0A Hydrologic response to igneous activity Excluded - Low 
Consequence 
6.2.2.9 
2.2.06.01.0A Seismic activity changes porosity and permeability of rock Excluded - Low 
Consequence 
6.2.1.9 
2.2.06.02.0A Seismic activity changes porosity and permeability of faults Excluded - Low 
Consequence 
6.2.1.10 
2.2.06.02.0B Seismic activity changes porosity and permeability of 
fractures 
Excluded - Low 
Consequence 
6.2.1.11 
2.2.06.03.0A Seismic activity alters perched water zones Excluded - Low 
Consequence 
6.2.1.12 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 7-2 November 2004 
The conclusions from this document (FEP Screening Decision, TSPA Disposition for included 
FEPs, or Screening Argument for excluded FEPs) along with any modifications to the FEP list, 
FEP names, and/or FEP descriptions will be incorporated in the Yucca Mountain TSPA-LA FEP 
database. Because this is the only subsequent use for the conclusions of this report, there are no 
restrictions on this use. Any uncertainties or limitations are generally related to input documents 
and repository design and have been previously described in Section 1.3. 
The FEP database will contain all Yucca Mountain FEPs considered for TSPA-LA with FEP 
number, name, description, and relevant FEP analysis reports where the documentation of the 
screening of specific FEPs is summarized. The FEP database will also contain screening 
decisions (Include or Exclude), screening arguments, and TSPA dispositions quoted from this 
and all other FEP analysis reports. 
All FEP information, including the 21 disruptive events FEPs considered in this report, will be 
submitted to the Technical Data Management System by the Yucca Mountain FEP database team 
as a final LA FEP list represented by a Data Tracking Number (DTN). Documentation of the 
FEP database is given in The Development of the Total System Performance Assessment License 
Application Features, Events, and Processes (BSC 2004 [DIRS 168706]). These final data will 
be qualified as technical product output within the above document. The final LA FEP list DTN 
will supersede all of the previous DTNs. 
Section 4.2.2 listed the relevant YMRP review criteria that apply to this report. Table 7-2 lists 
how this report addresses these criteria. 
Table 7-2. YMRP Acceptance Criteria Addressed in AMR 
YMRP 
Section 
Acceptance 
Criterion Description 
How Addressed in this 
Analysis Report 
1. The 
Identification of 
a List of FEPs 
Is Adequate 
The safety analysis report contains a complete list 
of FEPs related to the geologic setting or the 
degradation, deterioration, or alteration of 
engineered barriers (including those processes that 
would affect the performance of natural barriers) 
that have the potential to influence repository 
performance. The list is consistent with the site 
characterization data. The comprehensive 
features, events, and processes list includes, but is 
not limited to, potentially disruptive events related 
to igneous activity (extrusive and intrusive); seismic 
shaking (high-frequency-low magnitude, and rare 
large-magnitude events); tectonic evolution (slip on 
existing faults and formation of new faults); climatic 
change (change to pluvial conditions); and 
criticality. 
The list of disruptive 
events FEPs is provided in 
Section 1.2 (Table 1-1), 
and FEP descriptions are 
provided in Section 6.2. 
See Section 6.1.1 of this 
analysis report for a 
description and origin of 
the disruptive events FEP 
list and descriptions. 
Scenario 
Analysis and 
Event 
Probability: 
Scenario 
Analysis 
(from 
Section 
2.2.1.2.1.3 
NUREG- 
1804 
[DIRS 16327 
4]) 2. Screening 
of the Initial 
List of FEPs Is 
Appropriate 
The DOE has identified all FEPs related to either 
the geologic setting or to the degradation, 
deterioration, or alteration of engineered barriers 
(including those processes that would affect the 
performance of natural barriers) that have been 
excluded. 
See Table 7-1 for a list of 
excluded disruptive events 
FEPs. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 7-3 November 2004 
Table 7-2. YMRP Acceptance Criteria Addressed in AMR (Continued) 
YMRP 
Section 
Acceptance 
Criterion Description 
How Addressed in this 
Analysis Report 
The DOE has provided justification for those FEPs 
that have been excluded. An acceptable 
justification for excluding FEPs is that either the 
FEP is specifically excluded by regulation; 
probability of the FEP (generally an event) falls 
below the regulatory criterion; or omission of the 
feature, and process does not significantly change 
the magnitude and time of the resulting radiological 
exposures to the reasonably maximally exposed 
individual, or radionuclide releases to the 
accessible environment. 
See the method and 
approach discussion 
provided in Section 6.1.2 
and the individual 
justification (by regulation, 
low probability, low 
consequence) for 
excluding FEPs. The 
justification is also 
included in Table 7-1. 
The DOE has provided an adequate technical 
basis for each FEP, excluded from the 
performance assessment, to support the 
conclusion that either the FEP is specifically 
excluded by regulation; the probability of the FEP 
falls below the regulatory criterion; or omission of 
the FEP does not significantly change the 
magnitude and time of the resulting radiological 
exposures to the reasonably maximally exposed 
individual, or radionuclide releases to the 
accessible environment. 
See Section 6.2 for 
discussion of the individual 
FEP screening arguments 
and supporting technical 
bases. 
Events or event classes are defined without 
ambiguity and used consistently in probability 
models, such that probabilities for each event or 
event class are estimated separately. 
See the FEP disposition 
and screening argument 
provided for each FEP in 
Section 6.2. 
1. Events are 
Adequately 
Defined 
Probabilities of intrusive and extrusive igneous 
events are calculated separately. Definitions of 
faulting and earthquakes are derived from the 
historical record, paleoseismic studies, or 
geological analyses. Criticality events are 
calculated separately by location. 
See the FEP disposition 
and screening argument 
provided for each FEP in 
Section 6.2. 
Scenario 
Analysis and 
Event 
Probability: 
Identification 
of Events 
with 
Probability 
Greater than 
10-8 per Year 
(from Section 
2.2.1.2.2.3 
NUREG- 
1804 
[DIRS 16327 
4]) 
2. Probability 
Estimates for 
Future Events 
Are Supported 
by Appropriate 
Technical 
Bases 
Probabilities for future natural events are based on 
past patterns of the natural events in the Yucca 
Mountain region, considering the likely future 
conditions and interactions of the natural and 
engineered repository system. These probability 
estimates have specifically included igneous 
events, faulting and seismic events, and criticality 
events. 
See the FEP disposition 
and screening argument 
provided for each FEP in 
Section 6.2. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 7-4 November 2004 
Table 7-2. YMRP Acceptance Criteria Addressed in AMR (Continued) 
YMRP 
Section 
Acceptance 
Criterion Description 
How Addressed in this 
Analysis Report 
5. Uncertainty 
in Event 
Probability is 
Adequately 
Evaluated 
Probability values appropriately reflect 
uncertainties. Specifically: 
a. The DOE provides a technical basis for 
probability values used, and the values account for 
the uncertainty in the probability estimates. 
b. The uncertainty for reported probability values 
adequately reflects the influence of parameter 
uncertainty on the range of model results (i.e., 
precision) and the model uncertainty, as it affects 
the timing and magnitude of past events (i.e., 
accuracy). 
The technical basis and 
discussion of uncertainties 
used for exclusion of FEPs 
are discussed in the 
screening arguments of 
Section 6.2 for the 
individual FEPs. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 8-1 November 2004 
8. INPUTS AND REFERENCES 
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166107 

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for the Yucca Mountain Site Characterization Project. LA-12908-MS. Los Alamos, 
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100110 

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ANL-WIS-MD-000005 REV 02 8-5 November 2004 
Crowe, B.M.; Wohletz, K.H.; Vaniman, D.T.; Gladney, E.; and Bower, N. 1986. 
Status of Volcanic Hazard Studies for the Nevada Nuclear Waste Storage 
Investigations. LA-9325-MS. Volume II. Los Alamos, New Mexico: Los Alamos 
National Laboratory. ACC: NNA.19890501.0157. 
101532 
CRWMS M&O 1996. Probabilistic Volcanic Hazard Analysis for Yucca Mountain, 
Nevada. BA0000000-01717-2200-00082 REV 0. Las Vegas, Nevada: CRWMS 
M&O. ACC: MOL.19971201.0221. 
100116 
CRWMS M&O 1998. Disruptive Events. Chapter 10 of Total System 
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Document. B00000000-01717-4301-00010 REV 01. Las Vegas, Nevada: CRWMS 
M&O. ACC: MOL.19981008.0010. 
100369 
CRWMS M&O 1998. Probabilistic Seismic Hazard Analyses for Fault 
Displacement and Vibratory Ground Motion at Yucca Mountain, Nevada. Milestone 
SP32IM3, September 23, 1998. Three volumes. Las Vegas, Nevada: CRWMS 
M&O. ACC: MOL.19981207.0393. 
103731 
CRWMS M&O 1998. Synthesis of Volcanism Studies for the Yucca Mountain Site 
Characterization Project. Deliverable 3781MR1. Las Vegas, Nevada: CRWMS 
M&O. ACC: MOL.19990511.0400. 
105347 
Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Dickerson, R.P.; and Keefer, W.R. 1996. 
Structural Geology of the Central Block of Yucca Mountain. Chapter 2-I of 
Seismotectonic Framework and Characterization of Faulting at Yucca Mountain, 
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Dixon, T.H.; Robaudo, S.; Lee, J.; and Reheis, M.C. 1995. Constraints on 
Present-Day Basin and Range Deformation from Space Geodesy. Tectonics, 14, 
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Ferrill, D.A.; Winterle, J.; Wittmeyer, G.; Sims, D.; Colton, S.; Armstrong, A.; and 
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Fisher, R.V. and Schmincke, H.-U. 1984. Pyroclastic Rocks. New York, 
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Lachenbruch, A.H. and Sass, J.H. 1978. Models of an Extending Lithosphere and 
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Mongano, G.S.; Singleton, W.L.; Moyer, T.C.; Beason, S.C.; Eatman, G.L.W.; 
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ACC: MOL.20000324.0614. 
149850 
National Research Council. 1992. Ground Water at Yucca Mountain, How High 
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105162 
NRC (U.S. Nuclear Regulatory Commission) 1999. Issue Resolution Status Report 
Key Technical Issue: Structural Deformation and Seismicity. Rev. 2. Washington, 
D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.19991214.0623. 
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163274 
O'Brien, G.M. 1993. Earthquake-Induced Water-Level Fluctuations at Yucca 
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Parsons, T.; Thompson, G.A.; and Sleep, N.H. 1994. Mantle Plume Influence on 
the Neogene Uplift and Extension of the U.S. Western Cordillera? Geology, 22, 
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Ramelli, A.R.; Oswald, J.A.; Vadurro, G.; Menges, C.M.; and Paces, J.B. 1996. 
Quaternary Faulting on the Solitario Canyon Fault. Chapter 4.7 of Seismotectonic 
Framework and Characterization of Faulting at Yucca Mountain, Nevada. Whitney, 
J.W., ed. Milestone 3GSH100M. Denver, Colorado: U.S. Geological Survey. 
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Rogers, A.M.; Harmsen, S.C.; and Meremonte, M.E. 1987. Evaluation of the 
Seismicity of the Southern Great Basin and Its Relationship to the Tectonic 
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Rojstaczer, S. 1991. Elastic Deformation as a Second Order Influence on 
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104553 
Savage, J.C.; Svarc, J.L.; and Prescott, W.H. 1999. Strain Accumulation at Yucca 
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May 13-15, 1997. Miscellaneous Publication 98-2, 155-166. Salt Lake City, Utah: 
Utah Geological Survey. TIC: 246749. 
118967 
Stock, J.M. and Healy, J.H. 1988. Stress Field at Yucca Mountain, Nevada. 
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Disposal Site at Yucca Mountain, Southern Nevada. Carr, M.D. and Yount, J.C., 
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Stock, J.M.; Healy, J.H.; Hickman, S.H.; and Zoback, M.D. 1985. Hydraulic 
Fracturing Stress Measurements at Yucca Mountain, Nevada, and Relationship to the 
Regional Stress Field. Journal of Geophysical Research, 90, (B10), 8691-8706. 
Washington, D.C.: American Geophysical Union. TIC: 219009. 
101027 
Stuckless, J.S. 1996. Current Status of Paleohydrologic Studies at Yucca Mountain 
and Vicinity, Nevada. High Level Radioactive Waste Management, Proceedings of 
the Seventh Annual International Conference, Las Vegas, Nevada, April 29-May 3, 
1996. Pages 98-101. La Grange Park, Illinois: American Nuclear Society. 
TIC: 226494. 
119051 
Sweetkind, D.S.; Barr, D.L.; Polacsek, D.K.; and Anna, L.O. 1997. Administrative 
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Nevada. Milestone SPG32M3. [Las Vegas, Nevada]: U.S. Geological Survey. 
ACC: MOL.19971017.0726. 
100183 
Sweetkind, D.S.; Potter, C.J.; and Verbeek, E.R. 1996. Interaction Between Faults 
and the Fracture Network at Yucca Mountain, Nevada. Eos Transactions, S266. 
Washington, D.C.: American Geophysical Union. TIC: 236789. 
106957 
Thatcher, W.; Foulger, G.R.; Julian, B.R.; Svarc, J.; Quilty, E.; and Bawden, G.W. 
1999. Present-Day Deformation Across the Basin and Range Province, Western 
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119053 
Wernicke, B.; Davis, J.L.; Bennett, R.A.; Elosegui, P.; Abolins, M.J.; Brady, R.J.; 
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103485 
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MOL.19970129.0043; MOL.19970129.0044; MOL.19970129.0045; 
MOL.19970129.0046; MOL.19970129.0047; MOL.19970129.0048; 
MOL.19970129.0049; MOL.19970129.0050; MOL.19970129.0051; 
MOL.19970129.0052; MOL.19970129.0053; MOL.19970129.0054; 
MOL.19970129.0055; MOL.19970129.0056; MOL.19970129.0057; 
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161728 

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Repository at Yucca Mountain, Nevada. Readily available. 
155605 
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ACC: DOC.20041005.0008. 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 8-10 November 2004 
8.3 SOURCE DATA, LISTED BY DATA TRACKING NUMBER 
GS930108312312.003. Earthquake-Induced Water-Level Fluctuations at Yucca 
Mountain, Nevada, June, 1992. Submittal date: 01/21/1993. 
171974 
MO03061E9PSHA1.000. Spectral Acceleration and Velocity Hazard Curves 
Extended to 1E-9 Based on the Results of the PSHA for Yucca Mountain. Submittal 
date: 06/09/2003. 
163721 
MO0306MWDDPPDR.000. Drift Profile Prediction and Degraded Rock Mass 
Characteristics. Submittal date: 06/18/2003. 
164736 
MO0401MWDRPSHA.000. Results of the Yucca Mountain Probabilistic Seismic 
Hazard Analysis (PSHA). Submittal date: 01/21/2004. 
166962 
MO0407SEPFEPLA.000. LA FEP List. Submittal date: 07/20/2004. 170760 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 November 2004 
APPENDIX A 
LIST OF DIRECT INPUTS FOR INCLUDED AND EXCLUDED FEPS 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 November 2004 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-1 November 2004 
APPENDIX A 
LIST OF DIRECT INPUTS FOR INCLUDED AND EXCLUDED FEPS 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
CRWMS M&O 1996. Probabilistic 
Volcanic Hazard Analysis for Yucca 
Mountain, Nevada. BA0000000- 
01717-2200-00082 REV 0. 
Las Vegas, Nevada: CRWMS M&O. 
ACC: MOL.19971201.0221. 
100116 
Entire Sections 
6.2.1.1, C2.4 
Probabilistic Volcanic Hazard 
Assessment (PVHA) - technical 
basis for assessing hazards 
related to volcanism 
Data 
p. 4-10 Sections 
6.2.2.2, 
6.2.2.3 
Value of mean and percentile 
probability of dike intersections for 
PVHA 
Data 
Appendix E, p. 
AM-4 
Sections 
6.2.2.1, 
6.2.2.9 
Factors affecting drift orientation 
and vent alignment 
Data 
* Crowe, B.M.; Wohletz, K.H.; 
Vaniman, D.T.; Gladney, E.; and 
Bower, N. 1986. Status of Volcanic 
Hazard Studies for the Nevada 
Nuclear Waste Storage 
Investigations. LA-9325-MS. Volume 
II. Los Alamos, New Mexico: Los 
Alamos National Laboratory. 
ACC: NNA.19890501.0157. 
101532 
Entire Section 6.1.4 Used as direct input in Section 
6.2.2.5 for FEP 1.2.04.05.0A 
Data 
(qualified 
per APSIII.
2Q*) 
pp. 58-59 Section 
6.2.2.5 
Conclusion that exhumation of a 
repository by explosive cratering 
associated with water/magma 
interaction is unlikely; the depth of 
burial of a repository at Yucca 
Mountain exceeds the crater 
depth of the largest known 
hydrovolcanic craters. 
(Statement made on previously 
proposed repository depth of 380 
meters.) 
Data 
(qualified 
per APSIII.
2Q*) 
pp. 32-34 Section 
6.2.2.5 
Nye Canyon hydrovolcanic facies 
are on the scale of 1 km or less 
Data 
(qualified 
per APSIII.
2Q*) 
p. 47 Section 
6.2.2.5 
Listing of conditions conducive to 
hydrovolcanic feature formation 
Data 
(qualified 
per APSIII.
2Q*) 
Figure 19 Section 
6.2.2.5 
Plot of the relative frequency of 
crater depth for hydrovolcanic 
craters, maars, and tuff rings. The 
relative frequency of occurrence 
of hydrovolcanic craters greater 
than 215 meters deep is less than 
approximately 10 to 15 percent. 
Data 
(qualified 
per APSIII.
2Q*) 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-2 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
CRWMS M&O 1998. Probabilistic 
Seismic Hazard Analyses for Fault 
Displacement and Vibratory Ground 
Motion at Yucca Mountain, Nevada. 
Milestone SP32IM3, September 23, 
1998. Three volumes. Las Vegas, 
Nevada: CRWMS M&O. 
ACC: MOL.19981207.0393. 
103731 
Figure 8-5 Table 6-2 Annual frequency values Data 
Figure 4-9 Section 
6.2.1.2 
The Drill Hole Wash fault, Pagany 
Wash fault, and Sever Wash fault 
are northwest-trending parallel 
intra-block faults that intersect the 
emplacement drifts in the northeast 
section of the repository. 
Data 
Entire Sections 
6.2.1.1, 
6.2.1.2, 
6.2.1.3, 
6.2.1.4, 
6.2.1.5, 
6.2.1.6, 
6.2.1.11 
General cite to document providing 
results of expert elicitation on 
ground motion and fault 
displacement - source of ground 
motion and fault displacement 
data; and to support character of 
extensional tectonics 
Data 
p. 8-7 Sections 
6.2.1.2, 
6.2.1.10, 
6.2.1.11 
Results of expert elicitation for 
points 7d and 8d for intact rock - 
inference that new fractures will 
not affect porosity and permeability 
of fractures; reactivation of existing 
fractures is a more likely event 
than the development of new 
fractures. 
Data 
Figure 8-3 Table 6-2; 
Section 
6.2.1.10 
Fault displacement hazards for 
block-bounding faults 
Data 
Figures 8.2 
through 8.14; 
p. 8-7 
Section 
6.2.1.1; 
Table 6-2 
Fault displacement and other 
displacement hazards for 
intrablock faults and features likely 
to be found within the repository 
Data 
Figures 8.8 
through 8.13 
Section 
6.2.1.2 
Displacement hazard for features 
within the waste emplacement 
area 
Data 
Figures 8.10 
and 8.13 (for 
points 7c and 
8c) 
Section 
6.2.1.11 
Displacement hazards for fractures 
with no existing displacement 
Data 
Section 8.2.1 Table 6-2 General section reference of 
figures showing fault displacement 
hazard curves 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-3 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
Section 7.1.1 
and 8.1.3 and 
Appendix E 
Section 
6.2.1.1 
Discussions of the treatment of 
various types of uncertainty, 
specifically those related to rates, 
and summary of expert elicitations 
by team. 
Data 
National Research Council. 1992. 
Ground Water at Yucca Mountain, 
How High Can It Rise? Final Report 
of the Panel on Coupled 
Hydrologic/Tectonic/Hydrothermal 
Systems at Yucca Mountain. 
Washington, D.C.: National Academy 
Press. TIC: 204931. 
105162 
Entire Section C1 External source qualified for 
intended use 
Data 
(qualified for 
intended 
use  see 
Appendix C) 
Entire Section 
6.2.1.8 
Evaluation of seismic pumping 
hypothesis. 
Data 
CRWMS M&O 1998. Synthesis of 
Volcanism Studies for the Yucca 
Mountain Site Characterization 
Project. Deliverable 3781MR1. 
Las Vegas, Nevada: CRWMS M&O. 
ACC: MOL.19990511.0400. 
105347 
p. 5-42 Sections 
6.2.2.1, 
6.2.2.9 
Based on natural-analogue sites, 
there is no indication for extensive 
hydrothermal circulation and 
alteration, brecciation and 
deformation related to magmatic 
intrusion, and vapor phase 
recrystallization during the 
magmatic intrusion into the vitric 
and zeolitized tuffs. 
Data 
p. 5-56 Sections 
6.2.2.1, 
6.2.2.9 
Possibility of formation of perched 
water formation due to dike 
structure 
Data 
p. 5-41 and p. 
5-57 
Section 
6.2.2.1 
Mineral alterations around igneous 
intrusions at natural-analogue sites 
are generally confined to relatively 
thin zones. 
Data 
pp. 5-41, 5-72 Section 
6.2.2.1 
Natural-analogue studies in similar 
host rocks at the Nevada Test Site 
show that alteration is limited to a 
zone less than 10 meters away 
from the intrusion/host rock 
contact. 
Data 
pp. 5-1 and 5- 
2 
Section 
6.2.2.9 
Chemical and mineralogical 
studies of host tuffs indicated that, 
for shallow, small-volume basaltic 
intrusions, alteration is limited to 
within a few tens of meters of the 
intrusion itself. 
Data 
p. 5-46 Section 
6.2.2.9 
At the Paiute Ridge center, lowtemperature 
secondary minerals 
persist near the contact with 
intrusions. 
Data 
p. 5-86 Section 
6.2.2.9 
Consideration of the effects of 
hydrothermal systems (the heating 
up of groundwater and rock) 
resulting from igneous intrusions 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-4 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
p. 5-57 Section 
6.2.2.9 
Findings from the Paiute Ridge 
analogue site indicate that the 
occurrence of clinoptilolite and opal 
also suggests that thermal transfer 
into the adjacent country rock was 
minimal. 
Data 
p. 5-74 Section 
6.2.2.9 
Findings from the Grants Ridge 
site suggest the absence of a 
hydrothermal system, except for 
localized recrystallization of 
volcanic glass within the contact 
zone and leads to the conclusion 
that an intrusion at Yucca 
Mountain would not result in large 
amounts of hydrothermally driven 
mass transfer. 
Data 
p. 5-41 Section 
6.2.2.9 
The analogue studies show that 
alteration is quite limited, typically 
only found within 5 to 10 m of 
intrusions. 
Data 
10 CFR 63. Energy: Disposal of High- 
Level Radioactive Wastes in a 
Geologic Repository at Yucca 
Mountain, Nevada. Readily available. 
156605 
Section 114 
(d), (e), and (f) 
Section 1 The inclusion or exclusion of 
disruptive events FEPs with 
respect to modeling used to 
support the TSPA-LA is required. 
Established 
fact 
Section 73; 
Subparts F 
and G; also 
see 
requirements 
in Sections 
32, 44, and 
131 
Sections 
1.3, 6.1.6; 
Assumption 
5.3 
Engineering and design changes 
are subject to evaluation to 
determine whether there are any 
adverse impacts to safety. 
Established 
fact 
Entire Sections 
4.1, 4.2, 4.3, 
6.1.2 
The regulations provide direct 
inputs to the FEPs screening 
process. 
Established 
fact 
Section 2 Table 4-1 Regulatory definition for reference 
biosphere is given. 
Established 
fact 
Section 302 Table 4-1 Regulatory definitions for 
accessible environment and 
controlled area are given. 
Established 
fact 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-5 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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from 
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Use In Description 
Input 
Category 
Sections 
305(a),(b) 
Section 4.1; 
Table 4-1 
The reference biosphere must be 
consistent with present knowledge 
of conditions in the region, and 
changes in the biosphere (other 
than climate) from conditions at the 
time of license application 
submittal should not be projected. 
Established 
fact 
Section 305(c) Table 4-1; 
Assumption 
5.2 
Regulatory requirement given that 
the DOE vary factors based upon 
cautious, but reasonable, 
assumptions consistent with 
present knowledge of factors that 
could affect Yucca Mountain over 
the next 10,000 years. 
Established 
fact 
Section 312 Table 4-1 Regulatory characteristics of the 
RMEI are given. 
Established 
fact 
Section 
312(a), (b), 
(c), (d), and 
(e) 
Section 4.1 The location of the RMEI is defined 
specifically. 
Established 
fact 
Section 302 Sections 
4.1, 6.2.2.5 
Definition of the limit of the 
controlled area from the repository 
in directions other than south (i.e., 
south in the direction of 
groundwater flow referred to in 
Section 312). 
Established 
fact 
Sections 
102(i), 305, 
and 312 
Section 4.1 Characteristics of the reference 
biosphere and the RMEI are to be 
based on current human behavior 
and biospheric conditions in the 
region. 
Established 
fact 
Section 
114(a), (b), 
(d), (e), and 
(f); Section 
342 
Table 4-2 Applicable regulatory requirements 
pertinent to FEPs screening 
Established 
fact 
Section 114(d) Sections 
4.2.3, 6.1.2 
The low-probability criterion is 
stated. 
Established 
fact 
Section 342 Sections 
4.2.3, 6.1.2 
The low-probability criterion is 
supported. 
Established 
fact 
Section 114(e) 
and (f) 
Sections 
4.2.3, 6.1.2 
The low-consequence criterion is 
stated. 
Established 
fact 
Section 342 Section 
4.2.3 
The low-consequence criterion is 
supported. 
Established 
fact 
Section 102(j) Section 
4.2.3 
The concept of a performance 
assessment is given. 
Established 
fact 
Section 113(b) Section 
4.2.3 
Included in the concept of a 
performance assessment are 
those FEPs expected to materially 
affect compliance with what is 
stated in Section 113(b). 
Established 
fact 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-6 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
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Use In Description 
Input 
Category 
Entire Sections 4, 
6.2.2.2, 
6.2.2.3, 
6.2.2.5, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
Code of Federal Regulation rules 
governing the licensing of the U.S. 
Department of Energy to receive 
and possess source, special 
nuclear, and by-product material at 
a geologic repository operations 
area sited, constructed, or 
operated at Yucca Mountain, 
Nevada, in accordance with the 
Nuclear Waste Policy Act of 1982, 
as amended, and the Energy 
Policy Act of 1992. 
Established 
fact 
Sections 312 
and 302 
Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.5, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
The location of the RMEI is 
approximately 18 km south of the 
repository. 
Established 
fact 
BSC (Bechtel SAIC Company) 2003. 
21-PWR Waste Package Side and 
End Impacts. 000-00C-DSU0-01000- 
000-00B. Las Vegas, Nevada: 
Bechtel SAIC Company. 
ACC: ENG.20030227.0067. 
162293 
Entire Section 
6.2.1.3 
Damage to waste package and 
cladding supporting calculations 
include damage assessment of the 
21-PWR waste package. 
Data 
BSC (Bechtel SAIC Company) 2003. 
Maximum Accelerations on the Fuel 
Assemblies of a 21-PWR Waste 
Package During End Impacts. 000- 
00C-DSU0-01100-000-00A. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
ACC: ENG.20030327.0002. 
162602 
Entire Section 
6.2.1.3 
Damage to waste package and 
cladding calculations include 
determination of acceleration and 
damage to cladding package. 
Data 
BSC (Bechtel SAIC Company) 2003. 
Structural Calculations of Drip Shield 
Exposed to Vibratory Ground Motion. 
000-00C-PEC0-00100-000-00A. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
ACC: ENG.20030618.0009. 
163425 
Entire Section 
6.2.1.3 
Calculations that address damage 
to the drip shield from vibratory 
motion 
Data 
MO03061E9PSHA1.000. Spectral 
Acceleration and Velocity Hazard 
Curves Extended to 1E-9 Based on 
the Results of the PSHA for Yucca 
Mountain. Submittal date: 
06/09/2003. 
163721 
Entire Sections 
6.2.1.3, 
6.2.1.4, 
6.2.1.5, 
6.2.1.6 
Ground motion input data used in 
supporting analysis report 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-7 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
D&E / PA/C IED Subsurface 
Facilities. 800-IED-WIS0-00101-000- 
00A. Las Vegas, Nevada: Bechtel 
SAIC Company. 
ACC: ENG.20040309.0026. 
164519 
Entire Sections 
6.2.1.2, 
6.2.2.5 
The minimum depth of the 
currently planned TSPA-LA 
repository is 215 meters. 
Data 
MO0306MWDDPPDR.000. Drift 
Profile Prediction and Degraded Rock 
Mass Characteristics. Submittal date: 
06/18/2003. 
164736 
Entire Section 
6.2.1.6 
Seepage estimates made for 
collapsed drift profiles in 
lithophysal rocks 
Data 
BSC (Bechtel SAIC Company) 2003. 
Underground Layout Configuration. 
800-P0C-MGR0-00100-000-00E. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
ACC: ENG.20031002.0007. 
165572 
Sections 
7.1.3, 7.3.1 
Section 
6.2.1.2 
A standoff must be maintained 
from the closest edge of a 
repository opening to the main 
trace of any Type I fault zones. 
The preference location of the 
repository should be in the 
proposed repository block as 
defined by block bounding faults. 
Data 
Section 7.1.3 Section 
6.2.1.2 
The only Type I faults that would 
be required to have standoffs are 
the Solitario and Bow Ridge faults. 
Data 
Entire Section 
6.2.1.2 
Consideration of Exhumation due 
to Fault Displacement versus 
depth of repository 
Data 
BSC (Bechtel SAIC Company) 2004. 
Drift Degradation Analysis. ANL-EBSMD-
000027, Rev. 03. Las Vegas, 
Nevada: Bechtel SAIC Company. 
166107 
Section 
6.3.1.6.1; 
Tables 6-26, 
6-27 
Section 
6.2.1.4 
Results for the preclosure hazard 
level of 1 x 10-4 annual probability 
of exceedance ground motion 
indicate a total of 535 blocks per 
km of drift length. 
Data 
Entire Section 
6.2.1.11 
Field observations indicate that the 
rock at Yucca Mountain is highly 
fractured and that existing 
fractures and joints have been 
subject to reactivation. 
Data 
Sections 
6.3.1.6.1, 
6.4.2.2.2 
Section 
6.2.1.3 
Drift collapse occurs within the first 
second or two of the arrival of large 
amplitude ground motions. 
Data 
Sections 
6.3.4, 8.1 
Section 
6.2.1.4 
Nonlithophysal rock blocks are 
generally larger than rock 
fragments in the lithophysal zone, 
and drift profiles show more 
localized areas of rock failure. 
Data 
Sections 
6.3.1.2.1, 
6.4.2.2 
Sections 
6.2.1.4, 
6.2.1.5, 
6.2.1.6 
Site-specific ground motions for 
five levels of annual probability of 
exceedance are used to assess 
the postclosure seismically 
induced rock fall and seismicinduced 
drift collapse 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-8 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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from 
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Input 
Category 
Section 
6.4.2.2 
Sections 
6.2.1.4, 
6.2.1.6 
For 10-4 per year ground motions, 
little damage is predicted in 
lithophysal zones, even in 
unsupported areas of the drift 
Data 
Section 
6.4.2.2.2 
Section 
6.2.1.4 
Peak ground velocities in excess of 
about 2.0 m/sec result in damage 
levels above 15 m3 of rockfall per 
meter of emplacement drift length. 
This damage level is characterized 
by complete collapse of the tunnel 
at about the 10-6 hazard level 
Data 
Section 
6.4.2.5; Figure 
6-174 
Section 
6.2.1.5 
Rubble loads to the drip shield 
were estimated from collapse 
simulations using a discontinuum 
numerical model, and a threedimensional 
finite element 
structural analysis of the drip shield 
was undertaken. 
Data 
Entire Sections 
6.2.1.3, 
6.2.1.6; 
Table 6-1 
General reference to technical 
product addressing specifics of 
rockfall and drift collapse 
Data 
Table 6-50 Sections 
6.2.1.3, 
6.2.1.6, 
6.2.1.7 
General basis for inclusion Data 
Section 1.1 Section 
6.2.1.6 
The nonlithophysal rocks also 
comprise only 15 percent of the 
emplacement area 
Data 
Section 
6.4.2.2 
Section 
6.2.1.6 
Damage evaluations for lithophysal 
rockfall and drift collapse at 5 x10-4 
and at 10-6 ground motions. Drifts 
in the lithophysal zones collapse 
under the 10-6 per year (and by 
inference the larger, 10-7 per year) 
vibratory ground motions 
Data 
Sections 6.3 
and 6.4 
Section 
6.2.1.3, 
6.2.1.4, 
6.2.1.5 
Detailed description of the 
nonlithophysal rockfall calculations 
with the 3-DEC computer program 
(6.3 rockfall) and results 
summarized. Basis for argument 
that drift collapse occurs before 
drip separation occurs. 
Data 
Sections 6.3 
and 6.4 
Section 
6.2.1.4 
Rockfall occurs in both lithophysal 
and nonlithophysal zones 
substantially below the 10-6 annual 
probability of exceedance (PGV 
2.44 m/s) 
Data 
Section 
6.4.2.2 
Section 
6.2.1.6 
Drift collapse in nonlithophysal 
zones. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-9 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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from 
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Direct 
Use In Description 
Input 
Category 
Section 
6.3.1.6.1; 
Tables 6-26, 
6-27 
Section 
6.2.1.5 
For 10-5,10-6, and 10-7 per year 
ground motions, results indicate 
1,414 blocks, 2,238 blocks and 
3079 blocks per km of 
emplacement drift length, 
respectively, may move. 
Data 
Section 8.1 Section 
6.2.1.5 
Larger postclosure ground motions 
in nonlithophysal zones are 
characterized by localized areas of 
rock failure, in some cases 
sufficient to cover the drip shield. 
Data 
Section 6.6.1 Section 
6.2.1.5 
Due to the larger size of rock 
blocks, calculations have 
emphasized the impact of the size 
and kinetic energy of these larger 
blocks on the integrity of the drip 
shield, rather than the static load 
associated with lithophysal rubble. 
Data 
Appendix R Section 
6.2.1.6 
Seepage estimates made for 
collapsed drift profiles in 
lithophysal rocks provided in 
DTN: MO0306MWDDPPDR.000 
determined from analyses 
Data 
Entire Section 
6.2.1.6 
The worst-case (largest collapsed 
diameter) drift profile predicted by 
the drift-collapse analyses 
Data 
Section 6.3.1 Section 
6.2.1.6 
There is no explicit change in the 
seepage abstraction in the 
nonlithophysal zones because 
rockfall is localized and because 
there is limited impact on the 
shape and size of the drift profile. 
Data 
BSC (Bechtel SAIC Company) 2003. 
Scoping Analysis on Sensitivity and 
Uncertainty of Emplacement Drift 
Stability. 800-K0C-TEG0-00600-000- 
000. Las Vegas, Nevada: Bechtel 
SAIC Company. 
ACC: ENG.20031125.0002. 
166183 
Section 4.2.1 Section 
6.2.2.5 
The maximum overburden 
thickness of the currently planned 
TSPA-LA repository is 
approximately 450 meters. 
Data 
MO0401MWDRPSHA.000. Results of 
the Yucca Mountain Probabilistic 
Seismic Hazard Analysis (PSHA). 
Submittal date: 01/21/2004. 
166962 
Fault 
displacement 
values 
Table 6-2 Probabilistic fault displacement 
data for nine selected points in or 
near Yucca Mountain 
Data 
Fault 
displacement 
values 
Section 
6.2.1.10 
Results of the PSHA - data source 
for fault displacements and ground 
motions 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-10 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
Structural Calculations of Waste 
Package Exposed to Vibratory 
Ground Motion. 000-00C-WIS0- 
01400-000-00A. Las Vegas, Nevada: 
Bechtel SAIC Company. 
ACC: ENG.20040217.0008. 
167083 
Entire Section 
6.2.1.3 
Damage to waste package and 
cladding supporting calculations 
include analysis of the waste 
package vibratory motion. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Characterize Framework for 
Seismicity and Structural Deformation 
at Yucca Mountain, Nevada. ANLCRW-
GS-000003 REV 00 [Errata 
001]. Las Vegas, Nevada: Bechtel 
SAIC Company. 
ACC: MOL.20000510.0175; 
DOC.20040223.0007. 
168030 
Entire Sections 
6.2.1.2, 
6.2.1.7; 
Table 6-1 
General reference to analyses as 
supporting AMR. 
Data 
Entire Section 
6.2.1.2 
Supporting report for Fault 
Displacement Damages EBS 
Components FEP. 
Data 
Glossary and 
Section 6.4.2 
Assumption 
5.1 
Definition of annual exceedance 
probability 
Data 
Section 6.3.1 Sections 
6.2.1.1 
Extensional strain rate is low to 
moderate, with low to moderate 
seismicity. Experiencing declining 
strain rate. Time of peak tectonism 
was 12.7 to 11.6 million years ago. 
Data 
Table 6 Section 
6.2.1.2 
Fault slip rates at Yucca Mountain. Data 
Table 6 Section 
6.2.1.1 
Relevant fault-slip rates are in the 
range of 0.001 - 0.03 mm/year. 
Data 
Table 5 Section 
6.2.1.7 
Volcanic source zones 
considerations by expert teams 
Data 
Section 6.4.4 Section 
6.2.1.7 
PSHA method Data 
BSC (Bechtel SAIC Company) 2004. 
Additional Structural Calculations of 
Waste Package Exposed to Vibratory 
Ground Motion. 000-00C-WIS0- 
01700-000-00A. Las Vegas, Nevada: 
Bechtel SAIC Company. 
ACC: ENG.20040318.0011. 
168385 
Entire Section 
6.2.1.3 
Sensitivity studies conducted on 
variations in input ground motion 
parameters. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Total System Performance 
Assessment (TSPA) Model/Analysis 
for the License Application. MDLWIS-
PA-000004, Rev. 00. Las Vegas, 
Nevada: Bechtel SAIC Company. 
168504 
Section 
6.5.1.3 
Section 
6.2.1.6 
The fraction of waste packages 
affected is output from a TSPA-LA 
DLL 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-11 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Section 6.5 Sections 
6.2.1.2, 
6.2.1.3, 
6.2.1.6 
General reference to disposition of 
included components of the 
seismic scenario class in the 
TPSA-LA. 
Data 
Section 6.5.2 Section 
6.2.1.2 
Consequences from fault 
displacement and vibratory ground 
motion are calculated 
simultaneously in each TSPA-LA 
realization as damage 
abstractions. 
Data 
Section 6.5 Section 
6.2.1.2 
Output of fault displacement 
abstraction is number of waste 
packages failed by fault 
displacement and the combined 
surface area from all waste 
packages exposed to waste form 
dissolution and release. 
Data 
Section 6.5 Section 
6.2.1.2 
The total failed area from a faulting 
event is the weighted sum of the 
damage to each waste package 
group. 
Data 
Sections 
6.5.1, 6.5.2 
Sections 
6.2.1.2, 
6.2.1.3 
Fault-failed waste packages are 
further grouped into two bins: 
commercial spent nuclear fuel 
(CSNF) and co-disposal waste 
packages (CDSP), representing 
PWR, BWR and Naval waste 
packages and high level waste 
packages, respectively. These 
groups combine the EBS damage 
fraction from ground motion and 
fault displacement and account for 
different environmental conditions 
(e.g. dripping or dry). 
Data 
Entire Sections 
6.2.2.2, 
6.2.2.4, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8; 
Table 6-1 
General reference to the document 
as a supporting report for included 
FEP 
Data 
Section 6.4 Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.4, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
General reference to disposition of 
included components of the 
igneous scenario class in the 
TSPA-LA. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-12 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Section 
6.4.1.1 
Section 
6.2.2.2 
The time of the igneous intrusion is 
selected from a log-uniform 
distribution of possible event times 
with the minimum equal to the end 
of the first time step and the 
maximum equal to the end of the 
simulation period. 
Data 
Sections 
6.4.1.3 and 
6.4.1.1.2 
Section 
6.2.2.3 
Lookup tables are used to model 
magma temperature as a function 
of time to determine when seepage 
is reestablished. After 100 years, 
all TSPA-LA model variables, 
including temperatures, revert back 
to the nominal scenario TH 
abstraction values. 
Data 
Section 
6.4.2.3 
Section 
6.2.2.6 
The mass of waste to be included 
in the eruptive event is calculated 
based on the proportion of CSNF 
to CDSP waste packages in the 
repository and a sampled 
parameter that selects the number 
of waste packages affected by the 
eruptive event. The summation of 
events at a given time step is done 
within the GoldSim SoilExp_LA 
DLL as part of the source term 
multiplier calculations. 
Data 
Section 6.4.2 Section 
6.2.2.7 
The ASHPLUME code calculates 
the waste and ash deposition 
results (g/cm) at the RMEI location. 
The TSPA-LA model then converts 
the waste deposition at the RMEI 
location back to the masses of the 
individual radionuclide species and 
allows for radioactive decay. 
Data 
Section 
6.4.2.3 
Section 
6.2.2.8 
Ash redistribution calculations for a 
probabiltiy-weighted volcanic event 
are performed within TSPA-LA 
using the SoilExp_LA DLL. 
Data 
Section 
6.4.2.3 
Section 
6.2.2.8 
The TSPA model for the LA 
calculates dose from exposure due 
to inhalation, ingestion, and 
external exposure and its impact 
on the RMEI. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Drip Shield Structural Response to 
Rock Fall. 000-00C-SSE0-00300- 
000-00A. Las Vegas, Nevada: 
Bechtel SAIC Company. 
ACC: ENG.20040405.0019. 
168993 
Entire Section 
6.2.1.3 
Calculations that address damage 
to the drip shield from rockfall 
impact 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-13 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
Abstraction of Drift Seepage. MDLNBS-
HS-000019, Rev. 01. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
169131 
Entire Table 6-1 Supporting report for included FEP Data 
Section 
6.5.1.7 
Section 
6.2.2.9 
The seepage abstraction changes 
in the case of an igneous event 
because there is probably no 
capillary barrier to seepage in 
basalt-filled drifts. 
Data 
Section 6.3.1 Section 
6.2.1.6 
Anticipated post-seismic changes 
in the local in-drift environment 
include an increase in seepage 
mainly because of the larger size 
and the different shape of 
collapsed drifts. 
Data 
Section 
6.4.2.4 
Section 
6.2.1.6 
Systematic seepage simulations 
were conducted for the collapsed 
drift case using a full set of 
parametric variations of rock mass 
parameters, including capillary 
strength and percolation flux. 
Seepage analyses using the 
degraded drift profiles from the 
75th percentile and greatestdegradation 
cases of the rockfall 
analyses were performed. The 
seepage response determined for 
the nominal, circular drift profile is 
used in the seismic scenario for 
emplacement drifts in the 
nonlithophysal rocks. 
Data 
Section 
6.4.2.4.2 
Section 
6.2.1.6 
The effects of local rockfall in 
nonlithophysal zones and related 
drift- shape changes are small. 
Data 
Section 
6.5.1.5 
Section 
6.2.1.6 
The nominal seepage abstraction 
currently includes an enhancement 
factor of 20% to account for 
uncertainties related to local 
rockfall in the nonlithophysal units, 
and this enhancement factor is 
deemed adequate to address the 
impact of local rockfall related to 
seismic events. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Seismic Consequence Abstraction. 
MDL-WIS-PA-000003, Rev. 01. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
169183 
Sections 
6.6.1, 6.6.24 
Section 
6.2.1.4 
Impact energy for single and 
multiple rock blocks and related 
damage (lithophysal) and impact 
energy nonlithophysal (rockfall and 
drift collapse) 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-14 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Section 6.5.4 Section 
6.2.1.4 
Since the damaged areas remain 
physically intact, the most likely 
damage mechanism affecting the 
Titanium Grade 7 plates of the drip 
shield is accelerated stress 
corrosion cracking. Damage to the 
drip shield from rockfall is 
neglected for TSPA-LA 
Data 
Section 
6.6.1.2; 
Table 6.6-2 
Section 
6.2.1.4 
Example of the low consequence 
that these small fragments have 
upon impact with the drip shield 
shows that a lithophysal rock 
fragment kinetic energy does not 
produce a failed area on the 
surface of the drip shield 
(lithophysal) 
Data 
Table 6.2-1 Sections 
6.2.1.2, 
6.2.1.3, 
6.2.1.6 
General reference to basis for 
inclusion 
Data 
Entire Sections 
6.2.1.2, 
6.2.1.3, 
6.2.1.6; 
Table 6-1 
General reference as supporting 
document for included FEP 
Data 
Section 6.7.4 Section 
6.2.1.2 
At mean annual exceedance 
frequencies between 10-7 and 10-8 
per year, waste package failure 
may occur for any of the waste 
packages placed directly over 
certain identified locations. The 
probability of a fault displacement 
event severe enough to cause 
waste package failure is a function 
of both the specific fault (different 
fault displacements for a given 
probability) as well as the specific 
waste package design (different 
allowable displacements). 
Data 
Sections 6.7, 
6.7.2 
Section 
6.2.1.2 
Fault displacement along blockbounding 
and intra-block faults and 
features could impact waste 
packages mechanical damage 
caused by the fault displacement 
Data 
Section 
6.6.1.2 
Sections 
6.2.1.4, 
6.2.1.5 
Impact energy for single and 
multiple rock blocks and related 
damage (lithophysal) and impact 
energy and stress corrosion 
cracking in nonlithophysal (rockfall) 
Data 
Section 
6.6.2.1 
Sections 
6.2.1.4, 
6.2.1.5 
Lithophysal rock fragments have 
particle sizes on the order of 
centimeters to decimeters. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-15 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Category 
Sections 
6.7.5, 6.9.2 
Section 
6.2.1.2 
Uniform distribution sampled to 
develop abstraction for waste 
packages hit, assumes lower bond 
of 0 m2 and an upper bond equal to 
the area of the waste package lid. 
Allows advective and diffusive 
transport out of the waste package 
lid. 
Data 
Section 6.9.2 Sections 
6.2.1.2, 
6.2.1.6 
Fraction of failed surface area as a 
function of waste-package-type 
surface areas used in fault 
displacement abstraction. 
Seismically modified seepage is 
explicitly included by modifying the 
seepage flux in lithophysal zones 
following seismic-induced drift 
collapse. 
Data 
Section 5.1 Section 
6.2.1.3 
No damage to waste package and 
drip shield with horizontal peak 
ground velocities (PGV) of 0.190 
m/s and 0.384 m/s 
Data 
Sections 
6.7.4, 6.7.5 
Section 
6.2.1.2 
Number of waste packages failed 
based on correlation between 
displacement exceedance 
probabilities and expected number 
of failures for representative waste 
packages. 
Data 
Section 6.5 Section 
6.2.1.2 
Total failed area from faulting 
event is weighed sum of damage 
to waste package groups. 
Data 
Section 
6.5.4.1 
Section 
6.2.1.3 
Set of ground-motion time histories 
identical with that used for 
analyses of seismic rock fall and 
waste package structural 
response. 
Data 
Section 
6.5.7.2 
Section 
6.2.1.3 
Most, if not all, fuel pins will fail 
under vibratory ground motions at 
the 10-6 per year and the 10-7 per 
year levels. 
Data 
Section 6.7.5 Section 
6.2.1.2 
A sheared drip shield will allow all 
seepage to pass through it for 
TSPA-LA. 
Data 
Section 6.3.2 Section 
6.2.1.3 
Waste package damaged area 
larger than effective area 
susceptible to accelerated stress 
corrosion cracking. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-16 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Category 
Sections 
6.9.1.1, 5.1 
Section 
6.2.1.3 
Response range assumed 10-4 and 
10-8 1/yr spans the response of the 
system, from no damage at 10-4 
per year to the regulatory limit at 
10-8 per year. Horizontal PGV 
value corresponding to the 10-4 per 
year point on the hazard curve is 
0.0384 m/s 
Data 
Section 5.2 Section 
6.2.1.2 
Fault displacement hazard for Drill 
Hole Wash fault assumed to apply 
to Pagany Wash fault and Sever 
Wash fault. 
Data 
Sections 
6.7.1, 6.7.2.1, 
6.7.4; Tables 
6.7-5, 6.7-8 
Section 
6.2.1.2 
Maximum allowable (vertical) fault 
displacement compared to 
clearance between waste package 
and the drip shield. Comparison of 
clearances considers waste 
package group and collapsed or 
uncollapsed drifts 
Data 
Section 6.7.4 Section 
6.2.1.2 
Analysis concludes no damage will 
occur to waste package without 
tunnel collapse. 
Data 
Sections 
6.6.1.2 and 
6.3.6 
Section 
6.2.1.4 
Damage to the drip shield from 
impact of individual rock blocks is 
determined by structural response 
calculations. Damage calculations 
to drip shield areas use - residual 
stress exceeds the threshold value 
(50 percent of yield strength) for 
Titanium Grade 7 
Data 
Sections 6.3.1 
and 6.6.1 
Section 
6.2.1.4 
Rock blocks have the potential to 
result in immediate puncture or 
tearing of the drip shield if the 
localized strain exceeds the 
ultimate tensile strain 
Data 
Section 6.7.4 Section 
6.2.1.2 
Fault displacement values in 
Table 6-2 exceed the maximum 
allowable displacements for the 
binned waste types PWR, BWR, 
Naval and high-level radioactive 
waste 
Data 
Section 6.7 Section 
6.2.1.2 
Fault displacement consequences 
also includes pathway for seepage 
to contact the waste packages 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-17 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Section 6.7 Section 
6.2.1.2 
Shearing is assumed to occur 
perpendicular to the tunnel axis 
with the displacement being purely 
vertical 
Data 
Section 
6.9.1.2 
Section 
6.2.1.3 
PGVh is the 1D look-up table 
associated with mean annual 
exceedance frequencies between 
10-4 and 10-8 1/yr and PGV is the 
bounding PGV distribution used to 
calibrate results 
Data 
Sections 
6.5.1.3, 6.9.2 
Section 
6.2.1.3 
Damage to the waste package is 
applied to all waste packages in 
the repository. The damage 
abstraction for a waste package is 
defined by a uniform distribution 
with a lower bound of 0 percent 
damaged area and an upper 
bound that is a linear function of 
PGV. 
Data 
Sections 
6.5.3, 6.5.7, 
and 6.9.2 
Section 
6.2.1.3 
Within the TSPA-LA, the degree of 
ground motion damage is assumed 
to apply to all waste packages and 
CSNF cladding in the repository 
Data 
Section 
6.5.7.3 
Section 
6.2.1.3 
There is no spatial variability in the 
damage because damage to the 
cladding occurs within all waste 
packages 
Data 
Section 6.7.4; 
Table 6.7-9 
Section 
6.2.1.2 
Fault displacement hazard curves 
are used to tabulate the predicted 
fault displacement as a function of 
probability of the event and the 
resulting fault exceedance 
probabilities that would cause 
waste package failure. 
Data 
Section 6.8 Section 
6.2.1.6 
Post-seismic changes in the local 
in-drift environment in these zones 
are implemented in TSPA-LA 
Data 
Section 6.8.1 Section 
6.2.1.6 
Abstraction modifies seepage flux 
in lithophysal zones. The 10-6 
hazard level (PGV of 2.0 m/s) is 
considered a more reasonable 
threshold for drift collapse in the 
lithophysal zones. 
Data 
Sections 
6.7.2.1 and 
6.7.2.2 
Section 
6.2.1.2 
Intrablock faults and features are 
explicitly implemented within the 
TSPA-LA as consequences from 
damage to waste packages from 
fault displacement. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-18 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Category 
Section 
6.7.2.1 
Section 
6.2.1.2 
The western splay off the Ghost 
Dance fault intersects the 
repository in a contingency area; 
however, waste package 
placement there is uncertain and is 
also not considered in the analysis. 
Data 
Sections 6.7.5 
and 6.9.2 
Section 
6.2.1.2 
Cladding becomes 100 percent 
perforated in response to a fault 
displacement that can shear a 
waste package. 
Data 
Table 6.7-5 Table 6-2 Mean displacement values Data 
Section 4.1 Section 
6.2.1.3 
PGV of 2.44 m/s corresponds to 
the 10-6 per year exceedance 
frequency. PGV of 5.35 m/s 
corresponds to the 10-7 per year 
exceedance frequency 
Data 
Section 
6.5.7.2 
Section 
6.2.1.3 
To address the potential for 
damage at 1.05 m/s (10-5), the 
TSPA-LA conservatively assumes 
cladding damage 
Data 
Section 6.5.5 Section 
6.2.1.3 
Drip shield separation is excluded 
from TSPA-LA because (1) ground 
motion amplitudes that are 
sufficient to cause drip shield 
separation are also large enough 
to partially or completely collapse 
drifts in the repository, and (2) 
rockfall occurs within the first 
second or two of the arrival of 
these large amplitude ground 
motion. In this situation, rockfall 
provides restraints on the motion of 
the drip shields, preventing 
differential motion that could lead 
to separation 
Data 
Entire Section 
6.2.1.3 
Used structural response 
calculations for the waste package 
and drip shield as the basis for 
predicting failed areas for 
advective flow and transport 
Data 
Section 6.8.1 Section 
6.2.1.6 
Modified seepage is determined by 
using degraded drift seepage 
response surfaces in the form of 
look-up tables for lithophysal rock 
units 
Data 
Sections 6.8, 
6.9.2 
Section 
6.2.1.6 
Within the TSPA-LA, additional 
TSPA submodels address 
attendant effects on engineered 
barrier system flow 
Data 
Section 6.7.3 Section 
6.2.1.2 
Ghost Dance fault not considered 
in TSPA. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-19 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Input 
Category 
Section 
6.7.2.2 
Section 
6.2.1.2 
For faulting at locations other than 
at known faults, studies determine 
that 119.85 small fault 
intersections occur within drifts in 
lithophysal zones and 21.15 small 
fault intersections occur within 
drifts in nonlithophysal zones. This 
analysis is based on a study that 
quantified the likelihood of such 
smaller faults to intersect the 
emplacement drifts. 
Data 
Section 6.8.3 Section 
6.2.1.5 
In general, in nonlithophysal rock, 
rockfall volumes are sufficient to 
accumulate rock blocks adjacent to 
the drip shield; however, seismic 
shaking is not predicted to result in 
complete collapse of the drift. 
Data 
Section 6.5.4 Section 
6.2.1.5 
Ground motion amplitudes 
sufficient to separate drip shields 
are large enough to partially or 
completely collapse drifts in both 
lithophysal or nonlithophysal zones 
of the repository. The presence of 
even small frictional or gravitational 
loads has been shown to restrain 
the relative motion between 
adjacent drip shields. 
Data 
Sections 
6.1.3, 6.4.4 
Section 
6.2.1.3 
Site-specific ground motions used 
to assess postclosure analyses of 
damage to EBS components. 
Data 
Tables 4-1, 
6.1-1 
Section 
6.1.2 
For postclosure evaluation of faultdisplacement 
and seismic FEPs 
requiring ground motion inputs, the 
FEP screening statements are 
applied based on the mean value 
of the event at an annualexceedance 
probability of 10-8. 
Data 
Section 
6.6.1.2 
Section 
6.2.1.5 
Structural response calculations of 
damage to the drip shield from the 
impact of individual rock blocks 
model six representative rock 
blocks, ranging in weight from 0.11 
MT to 14.5 MT. 
Data 
Section 6.8.1 Section 
6.2.1.6 
There is no explicit change in the 
seepage flux into the emplacement 
drifts in nonlithophysal zones. 
Data 
Section 6.8.1 Section 
6.2.1.6 
A threshold temperature of 100 
degrees C is based on a sensitivity 
study of seepage arrival times at 
the drip shield crown for a 
collapsed drift that is filled with 
rubble. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-20 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Input 
Category 
Section 6.9.2, 
Number 14 
Section 
6.2.1.6 
Temperature and relative humidity 
affecting the waste packages after 
drift collapse in the lithophysal 
zones is implemented in TSPA at 
all ground motions with a PGV 
greater than 0.384 m/s. 
Data 
Section 6.8.3 Section 
6.2.1.6 
The temperature and relative 
humidity of the waste package 
after drift collapse are defined by 
the calculations with the multiscale 
thermohydrologic model. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Dissolved Concentration Limits of 
Radioactive Elements. ANL-WIS-MD- 
000010, Rev. 03. Las Vegas, 
Nevada: Bechtel SAIC Company. 
169425 
Entire Section 
6.2.2.4 
Use the solubility look-up table in 
TSPA implementation. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Multiscale Thermohydrologic Model. 
ANL-EBS-MD-000049, Rev. 02. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
169565 
Entire Section 
6.2.1.6; 
Table 6-1 
Supporting document for included 
FEP 
Data 
BSC (Bechtel SAIC Company) 2004. 
Mechanical Assessment of the Drip 
Shield Subject to Vibratory Motion 
and Dynamic and Static Rock 
Loading. CAL-WIS-AC-000002 REV 
00. Las Vegas, Nevada: Bechtel 
SAIC Company. 
169753 
Entire Section 
6.2.1.3 
Calculations of the waste package 
and cladding damage resulting 
from vibratory motion are 
summarized; used structural 
response calculations for the waste 
package and drip shield as the 
basis for predicting failed areas for 
advective flow and transport. 
Consideration of the timing and 
effects of seismic-induced drift 
collapse and rock fall to potential 
drip shield separation is done. 
Data 
Entire Section 
6.2.1.3; 
Table 6-1 
Supporting report for included 
FEP. 
Data 
Entire Section 
6.2.1.5 
Higher probability (e.g., 10- 5) 
events are more likely than single, 
lower probability (e.g., 10-7) events, 
suggesting drift will be filled prior to 
an extreme, more unlikely seismic 
event. Significant rubble is 
expected in the drift to confine the 
drip shield prior to the occurrence 
of an extreme event that would 
result in drip shield displacement. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-21 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Category 
Entire Section 
6.2.1.3 
Damage to drip shield from 
vibratory ground motion is 
determined by structural response 
calculations that consider seismicinduced 
rockfall and seismicinduced 
drift collapse. 
Data 
Section 5.3.3 Sections 
6.2.1.3, 
6.2.1.5 
Idealized dynamic kinematic 
analyses of a large number of 
interlocked drip shields subjected 
to selected ground motion time 
histories with PGV of 2.44 m/s and 
5.35 m/sec were completed. These 
analyses show that the weight or 
frictional resistance of rubble 
against the drip shield completely 
prevents separation, even at 
ground motions representative of 
annual exceedance frequency of 
1x10-7 per year, or 5.35 m/sec 
PGV level. 
Data 
Entire Section 
6.2.1.3 
Calculations of the waste package 
and cladding damage resulting 
from vibratory motion are 
summarized; used structural 
response calculations for the waste 
package and drip shield as the 
basis for predicting failed areas for 
advective flow and transport. 
Consideration of the timing and 
effects of seismic-induced drift 
collapse and rock fall to potential 
drip shield separation is done. 
Data 
Section 5.4.3 Section 
6.2.1.5 
Six realizations of the collapse 
response and loading to the drip 
shield structure were conducted 
and used as input to a threedimensional 
finite element 
structural analysis of the drip 
shield. 
Data 
Section 5.4.3 Section 
6.2.1.5 
The average vertical load that 
results in excessive plastic 
deformation is approximately 3.25 
times the average vertical pressure 
from the six collapse realizations 
described above. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Drift Scale THM Model. MDL-NBSHS-
000017, Rev. 01. Las Vegas, 
Nevada: Bechtel SAIC Company. 
169864 
Entire Section 
6.2.1.9 
The effects of thermal stress are 
evaluated in terms of changes to 
rock fracture properties, but not 
rock matrix, implicitly recognizing 
the negligible impact of stressinduced 
changes on rock matrix. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-22 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
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from 
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Direct 
Use In Description 
Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
Engineered Barrier System Features, 
Events, and Processes. ANL-WISPA-
000002, Rev. 03. Las Vegas, 
Nevada: Bechtel SAIC Company. 
169898 
Entire Sections 
6.2.1.2, 
6.2.1.3, 
6.2.1.6 
Fault displacement - shared FEP 
seismic consequence fault 
displacement and ground motion. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Characterize Eruptive Processes at 
Yucca Mountain, Nevada. ANL-MGRGS-
000002, Rev. 02. Las Vegas, 
Nevada: Bechtel SAIC Company. 
169980 
Table 7-1 Section 
6.2.2.7 
Summary of parameters and 
distributions for the analysis 
Data 
Table 6-1 Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
General reference to justification 
for inclusion of FEP 
Data 
Entire Sections 
6.2.1.7, 
6.2.2.2, 
6.2.2.3, 
6.2.2.5, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8; 
Table 6-1 
General reference to the analysis 
as a supporting document for 
included FEP 
Data 
Section 6.5 Sections 
6.2.2.7, 
6.2.2.8 
Includes the results of field 
investigations and presents the 
detailed conceptual and technical 
basis for the ash redistribution 
model 
Data 
Section 6 Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6, 
6.2.2.7 
General reference to analyses and 
field observations pertinent to 
basaltic eruptions, and to 
properties and characteristics of 
basaltic magma 
Data 
Section 
6.3.1.3 
Section 
6.2.1.7 
Dike length distribution used by the 
PVHA used as a proxy for surfacefault 
lengths to calculate maximum 
magnitudes of dike-induced 
earthquakes 
Data 
Appendix 
C3.3 
Section 
6.2.2.5 
A detailed description of 
hydrovolcanic or pyroclastic surge 
deposits at the Lathrop Wells 
volcano. 
Data 
Entire Section 
6.2.2.3 
General reference that output is 
used to assess the number of 
waste packages exposed to Zone 
1 (intersected drifts) magmatic 
environment 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-23 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Input 
Category 
Section 
6.1.3.2 
Section 
6.2.2.5 
Definition of hydrovolcanic eruption 
process 
Data 
Appendix 
C2.1 
Section 
6.2.2.5 
Evidence of a brief hydrovolcanic 
event late in the cone-building 
history of Lathrop Wells volcano 
Data 
BSC (Bechtel SAIC Company) 2004. 
Characterize Framework for Igneous 
Activity at Yucca Mountain, Nevada. 
ANL-MGR-GS-000001, Rev. 02. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
169989 
Section 6.3.2 Sections 
6.2.2.1, 
6.2.2.9 
The aggregate dike-length 
distribution derived from the PVHA 
has a mean value of 4.0 km, and 
the most commonly assigned dike 
orientation centers on N30E. 
Data 
Sections 
6.1.1.1, 
6.4.1.1 
Section 
6.2.1.1 
Description of fault blocks and their 
formation in Yucca Mountain 
region. 
Data 
Table 6-1 Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6 
Direct input source for inclusion of 
FEP 1.2.04.03.0A. 
Data 
Entire Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6, 
6.2.2.8; 
Table 6-1 
General reference as basis for 
inclusion of FEP as supporting 
analysis report. 
Data 
Entire Sections 
6.2.1.1, 
6.2.2.1, 
6.2.2.3, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8, 
6.2.2.9 
General reference to the analysis 
report, which presents probability 
distributions for length and 
orientation of dikes. 
Data 
Table 6-21 Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.5, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
Probability of igneous intrusion and 
probability of eruptive center 
forming within the repository 
footprint 
Data 
Section 6.2 Sections 
6.2.2.1 and 
6.2.2.9 
Probabilistic distribution of dikes 
and Paiute Ridge 
Data 
Section 
6.3.2.1 
Sections 
6.2.2.1 and 
6.2.2.9 
Paiute Ridge as natural analogue 
to assess change in rock 
properties 
Data 
Section 6.2 Section 
6.2.2.5 
Extent and volume of lava flows 
from the surrounding Quaternary 
basaltic volcanoes 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-24 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Section 
6.3.1.3 
Section 
6.2.1.1 
PVHA experts incorporated the 
possibility that volcanic events are 
clustered in time or to describe the 
possible waning or waxing of 
volcanic activity in the region 
Data 
BSC (Bechtel SAIC Company) 2004. 
Number of Waste Packages Hit by 
Igneous Intrusion. ANL-MGR-GS- 
000003, Rev. 01. Las Vegas, 
Nevada: Bechtel SAIC Company. 
170001 
Section 6.4 Section 
6.2.2.6 
For the volcanic eruption modeling 
case, a CDF is sampled to 
calculate the number of waste 
packages hit by eruptive conduits 
in a TSPA realization. 
Data 
Section 6.3.4 Section 
6.2.2.3 
The number of waste packages hit 
analysis results include CDFs for 
the number of waste packages 
impacted in an igneous intrusion 
scenario and in an eruptive release 
scenario. 
Data 
Table 6-1 Sections 
6.2.2.3, 
6.2.2.6 
Table of included FEPS in the 
document: basis for inclusion. 
Data 
Entire Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6; 
Table 6-1 
General reference to the analysis 
as supporting the included FEP. 
Data 
Section 6.3 Section 
6.2.2.2 
For each TSPA realization, a CDF 
is sampled to determine the 
number of destroyed waste 
packages to use as the source 
term. The CDF is based on a 
series of 3000 realizations of dike 
swarm configurations that could 
intersect the repository, a TSPALA 
assumption that all waste 
packages in an intersected drift are 
compromised, and on a magma 
bulkhead analysis that concludes 
that magma is contained within an 
intersected drift. 
Data 
Entire Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6 
General reference to the analysis 
of number of waste package hit by 
igneous intrusion or eruptive event. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-25 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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from 
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Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
Features, Events, and Processes in 
UZ Flow and Transport. ANL-NBSMD-
000001, Rev. 03. Las Vegas, 
Nevada: Bechtel SAIC Company. 
170012 
Appendix D Sections 
6.2.1.1, 
6.2.1.8, 
6.2.1.10, 
6.2.1.11, 
6.2.2.1 
Effect of increased fracture 
aperture on percolation flux on UZ 
domain scale is negligible 
compared to infiltration uncertainty. 
The results also show that fracture 
aperture changed confined to fault 
zones result in virtually no effect on 
transport behavior in the UZ. 
Changes in fault and fracture 
properties due to igneous activity 
(i.e., activation, creation, and 
sealing of faults and fractures) are 
also judged to be of negligible 
impact. 
Data 
Section 6.8.8 Section 
6.2.1.12 
The UZ flow model shows that the 
volume of perched water in the 
high-permeability fracture domain 
below the repository only ranges 
from about 466 m3 to 1,190 m3. 
Data 
Section 6.7.5 Section 
6.2.1.9 
Changes to the rock matrix 
porosity and permeability caused 
by changes in rock stress are 
negligible compared with changes 
to the fracture porosity and 
permeability 
Data 
Section 6.7.8 Section 
6.2.1.12 
Perched water zones below the 
elevation of the repository have 
been found in site characterization 
boreholes. 
Data 
Appendix A Section 
6.2.1.12 
Perched water zone volume 
calculation. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Atmospheric Dispersal and 
Deposition of Tephra from a Potential 
Volcanic Eruption at Yucca Mountain, 
Nevada. MDL-MGR-GS-000002, 
Rev. 01. Las Vegas, Nevada: Bechtel 
SAIC Company. 
170026 
Sections 1.0 
and 6.5.2 
Section 
6.2.2.6 
A CDF provides the mass of waste 
available for incorporation with ash 
particles, which is required as an 
input for the ASHPLUME_DLL_LA 
software within the TSPA LA. 
Data 
Sections 
6.3.2, 6.6.3 
Section 
6.2.2.8 
A hypothetical direct deposition of 
ash and waste in the vicinity of the 
RMEI, and local redistribution of 
that waste, presumably represents 
the greatest degree of exposure 
from an eruptive process. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-26 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
Section 6.5 Section 
6.2.2.8 
For the volcanic eruption modeling 
case, the TSPA-LA presumes that 
a hypothetical violent Strombolian 
eruption occurs through a section 
of the repository, entraining 
radionuclide-bearing wastes in an 
ash plume that disperses 
downwind and deposits 
contaminated ash on the ground 
surface. 
Data 
Section 6.7.2 Section 
6.2.2.8 
Parameters used by SoilExp_LA 
DLL within GoldSim 
Data 
Sections 
6.3.2, 6.6.3 
Section 
6.2.2.8 
A hypothetical direct deposition of 
ash and waste in the vicinity of the 
RMEI, and local redistribution of 
that waste, presumably represents 
the greatest degree of exposure 
from an eruptive process 
Data 
Section 5.1.3 Section 
6.2.2.8 
For Outcome 1 (discussed in Table 
6-3) - A volume of transported 
sediment with a diluted ash 
component would have less impact 
on the RMEI than would a primary 
ashfall that fell directly on the 
RMEI. 
Data 
Sections 
5.1.3, 6.3.2 
Section 
6.2.2.8 
For Outcome 2 (discussed in 
Table 6-3) - Direct deposition of 
ash and waste occurs outside the 
vicinity of the RMEI. Deposition 
may occur in any direction, 
depending on the sampled wind 
direction. Other tephra-sheet 
orientations either eliminate ash 
from reaching the RMEI location, 
or reduce the available volume of 
ash to be redistributed to the RMEI 
location. 
Data 
Sections 
1.3.2, 6.7.2.4 
Section 
6.2.2.8 
Given uncertainties, the TSPA-LA 
assumes an ash layer to remain 
indefinitely with the sampled initial 
thickness but with 1/100th of the 
initial volumetric concentration 
derived from the separate 
ASHPLUME calculation. 
Data 
Table H-2 Section 
6.2.2.6 
Mean particle size diameters of 
waste vary from 0.002 cm for 
unaltered fuel to 0.0002 cm for 
corroded fuel. 
Data 
Sections 6.5.1 
and 6.5.2 
Sections 
6.2.2.6, 
6.2.2.7 
The mathematical model and 
parameter inputs used in the 
ASHPLUME model to calculate 
ash-and-waste dispersal in the 
wind. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-27 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
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Direct 
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Input 
Category 
Section 
6.5.2.16 
Section 
6.2.2.6 
Technical basis for assuming 
erupted materials are finely divided 
particles amenable for airborne 
transport 
Data 
Table 6-1 Sections 
6.2.2.6, 
6.2.2.7, 
6.2.2.8; 
Table 6-1 
Reference for inclusion as FEP Data 
Entire Sections 
6.2.2.3, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
General reference to models and 
analyses addressing transport of 
waste in volcanic ash 
Data 
Table 6-3 Section 
6.2.2.7 
Parameters used to implement 
FEP 1.2.04.07.0A within the TSPALA 
Data 
Section 6.5.2 Section 
6.2.2.7 
Technical basis for parameters 
developed within the ASHPLUME 
model report 
Data 
Sections 
1.3.2, 6.6 
Section 
6.2.2.8 
Conceptual model for redistribution Data 
Section 
6.7.2.2; 
Table 6-5 
Table 6-3 Ash redistribution factors for the 
TSPA model. 
Data 
Sections 
6.7.2.3 and 
6.7.2.4 
Section 
6.2.2.8 
Redistribution conceptual model, 
including landforms, interchannel 
divide areas (82%), and 
distributary channels (18%) used in 
TSPA-LA redistribution abstraction 
are discussed. Also, discussed are 
two different geomorphic settings 
areas and how they respond 
differently to ash fall and 
redistribution. 
Data 
Section 8.1 Sections 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
Reference to discussion regarding 
use of ASHPLUME model 
Data 
BSC (Bechtel SAIC Company) 2004. 
Development of Earthquake Ground 
Motion Input for Preclosure Seismic 
Design and Postclosure Performance 
Assessment of a Geologic Repository 
at Yucca Mountain, NV. MDL-MGRGS-
000003, Rev. 01. Las Vegas, 
Nevada: Bechtel SAIC Company. 
170027 
Table 6.4-2 Section 
6.2.1.7 
Supporting model report 
documenting decision to include 
the FEP and providing TSPA 
disposition information 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-28 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
Entire Sections 
6.2.1.3, 
6.2.1.4, 
6.2.1.5, 
6.2.1.6; 
Table 6-1 
General reference to document 
providing ground motion input 
analysis 
Data 
Section 6.5 Section 
6.2.1.7 
An analysis of the ground motion 
associated with the range of 
maximum magnitude earthquakes 
assessed for basalt dike intrusions 
is presented. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Dike/Drift Interactions. MDL-MGRGS-
000005, Rev. 01. Las Vegas, 
Nevada: Bechtel SAIC Company. 
170028 
Section 6.8.6 Section 
6.2.2.3 
As oxide and silicate minerals tend 
to have slow dissolution rates 
compared to salts, significantly 
enhanced dissolution rates of 
minerals due to reaction of waste 
with basalt magma within drifts is 
not anticipated, and is not 
considered further. 
Data 
Section 
6.5.5.1 and 
Figure 6-93 
Section 
6.2.2.4 
Simulations suggest only a brief 
and minimal decrease in pH 
around the drift in the liquid phase 
at about one year. 
Data 
Section 6.6 Section 
6.2.2.4 
Relative to the potential impact of 
magmatic volatiles on water 
chemistry, magmatic volatile 
release may lead to zones of low 
pH in regions adjacent to potential 
igneous intrusions. 
Data 
Equation 6-95 Equation 6- 
1 
Shows that hydrogen ions are 
consumed in hydrolysis reactions, 
leading to the neutralization of 
acidity. 
Data 
Figure 6-88 Section 
6.2.2.4 
During the first year or two 
following intrusion, temperatures at 
the edge of the drift remain above 
100 degrees C, which prevents 
seepage into the drift. 
Data 
Figure 6-93 Section 
6.2.2.4 
Between one and five years 
following intrusion, the narrow 
zone of decreased pH is not 
evident in simulations. 
Data 
Section 6.6 Section 
6.2.2.4 
Analyses demonstrate that 
migration of magmatic volatiles to 
Zone 2 drifts (non-intersected 
drifts) is not a concern. 
Data 
Entire Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.4, 
6.2.2.5, 
6.2.2.6 
General reference to the dike/drift 
interaction models and analyses 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-29 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
Section 6.4.5 Section 
6.2.2.6 
Discussion of the treatment of the 
dog-leg scenario 
Data 
Section 6 Section 
6.2.2.3 
Potential migration of heat and gas 
between Zone 1 (intersected drifts) 
and Zone 2 (non intersected drifts) 
Data 
Table 6-1 Section 
6.2.2.2, 
6.2.2.3, 
6.2.2.4; 
Table 6-1 
General reference for inclusion or 
as a supporting document 
Data 
Section 6 Section 
6.2.2.3 
Factors influencing post-intrusion 
environmental conditions within the 
drifts 
Data 
Section 6.4 Section 
6.2.2.3 
The outputs of the model indicate 
that the entire length of an 
intersected drift has the potential to 
be filled with magmatic materials. 
Data 
Section 6.4.9 Section 
6.2.2.3 
During the course of magma 
cooling, waste packages and 
canisters /assemblies may be 
subject to corrosion. Within the 
TSPA-LA, no credit is taken for any 
partial protection that residual 
elements of the waste package 
shells and the encapsulating basalt 
might provide. 
Data 
Figures 6-88 
and 6-89 
Section 
6.2.2.3 
Figures show temperatures 
associated with igneous intrusion 
attenuate rapidly into tuff 
surrounding the drift. 
Data 
Sections 
6.6.5.1 and 
6.6.5.2 
Section 
6.2.2.3 
Simulations of gas flow show no 
impacts are anticipated for Zone 2 
waste packages. 
Data 
Figure 6-86 Section 
6.2.2.3 
Initially high CO2 and SO2 
concentrations migrate well outside 
drifts as magmatic volatiles 
Data 
Sections 
6.6.5.3 and 
6.6.6 
Section 
6.2.2.3 
Separate calculation to evaluate 
gas flow through backfill keyway 
indicates migration occurs, but 
combination of dilution of 
magmatic gases by air (in adjacent 
drift) and retardation of gas by 
moisture in pore space in backfill 
keyway indicates no damage to 
waste packages in Zone 2 
Data 
Section 
6.4.8.3 
Section 
6.2.2.3 
As temperatures decrease after 
magma emplacement, UO2 is 
expected to fragment, which 
increases the surface area of the 
waste. 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-30 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
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from 
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Direct 
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Input 
Category 
Section 6.8 Section 
6.2.2.4 
Seepage reaction with cooled 
basalt and hydrochemistry using 
the software package EQ3/6 
Data 
Section 6.8.4 Section 
6.2.2.4 
TSPA look-up tables for seepage 
composition  time intervals are 
defined in the TSPA-LA. 
Data 
Section 6.8.3 Section 
6.2.2.4 
Minimum and maximum of the 
time-weighted averages from the 
EQ3/6 calculations are consistent 
with the large time steps used in 
the TSPA-LA igneous intrusion 
groundwater transport model. 
Data 
Section 5.4.1 Sections 
6.2.2.3, 
6.2.2.9 
Following resumption of seepage, 
the abstraction used for the TSPA 
LA model will use typical seepage 
flux from the crown. The 
permeability of any contact 
metamorphic aureole surrounding 
the intruded drifts is as great as 
that of the bulk host rock. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Saturated Zone Flow and Transport 
Model Abstraction. MDL-NBS-HS- 
000021, Rev. 02. Las Vegas, 
Nevada: Bechtel SAIC Company. 
170042 
Section 6.5.2 Sections 
6.2.1.10, 
6.2.1.11 
General reference to flowing 
interval method used to address 
fracture effects in the SZ modeling 
Data 
Section 
6.5.2.10 
Sections 
6.2.2.1, 
6.2.2.9 
Direction of anisotropic maximum 
transmissivity may be N15 degrees 
E. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Mechanical Assessment of the Waste 
Package Subject to Vibratory Ground 
Motion. CAL-WIS-AC-000001 REV 
00A. Las Vegas, Nevada: Bechtel 
SAIC Company. 
170063 
Entire Section 
6.2.1.3; 
Table 6-1 
Used structural response 
calculations for the waste package 
and drip shield as the basis for 
predicting failed areas for 
advective flow and transport. A 
supporting document for inclusion 
of a FEP. 
Data 
MO0407SEPFEPLA.000. LA FEP 
List. Submittal date: 07/20/2004. 
170760 
S04311_001 Sections 1, 
1.2, 4.1, 
6.1.1 
Features, events, and processes 
applicable to the Yucca Mountain 
Project as revised for the License 
Application phase. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Structural Stability of a Drip Shield 
Under Quasi-Static Pressure. 000- 
00C-SSE0-00500-000-00A. 
Las Vegas, Nevada: Bechtel SAIC 
Company. 
ACC: ENG.20040830.0032. 
170791 
Entire Section 
6.2.1.3 
Calculations that address damage 
to the drip shield from quasi-static 
pressure from rockfall rubble 
Data 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-31 November 2004 
Table A-1. Table of Direct Inputs for Included and Excluded Features, Events, and Processes 
(Continued) 
Document Source 
Citation 
from 
Source 
Direct 
Use In Description 
Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
Alternative Damaged Area Evaluation 
for Waste Package Exposed to 
Vibratory Ground Motion. 000-00CWIS0-
01900-000-00A. Las Vegas, 
Nevada: Bechtel SAIC Company. 
ACC: ENG.20040420.0010. 
170843 
Entire Section 
6.2.1.3 
Sensitivity studies conducted on 
variations in input ground motion 
parameters. 
Data 
BSC (Bechtel SAIC Company) 2004. 
21-PWR Waste Package End 
Impacts - A Mesh Study. 000-00CWIS0-
02100-000-00A. Las Vegas, 
Nevada: Bechtel SAIC Company. 
ACC: ENG.20040617.0005. 
170844 
Entire Section 
6.2.1.3 
Damage to waste package and 
cladding calculations include 
sensitivity studies of the 21-PWR 
finite element model. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Magma Bulkhead Analysis. 800-K0CSSP0-
00100-000-00A. Las Vegas, 
Nevada: Bechtel SAIC Company. 
171070 
Entire Section 
6.2.2.3 
The possibility for magma flow to 
flow between drifts is assessed in 
a calculation. 
Data 
BSC (Bechtel SAIC Company) 2004. 
Subsurface Facility Description 
Document. 800-3YD-SS00-00100- 
000-000. Las Vegas, Nevada: 
Bechtel SAIC Company. 
ACC: ENG.20040915.0008. 
171676 
Section 
3.1.1.4.8.6 
Section 
6.2.1.2 
Standoff from Quaternary faults 
with potential for significant 
displacement requirement 
Data 
GS930108312312.003. Earthquake- 
Induced Water-Level Fluctuations at 
Yucca Mountain, Nevada, June, 
1992. Submittal date: 01/21/1993. 
171974 
Entire Section 
6.2.1.8 
Data from the groundwater 
monitoring wells document the 
1992 earthquake-induced 
fluctuations in water level. 
Data 
* Qualification of Igneous Inputs to Features, Events, and Processes: Disruptive Events (BSC 2004 [DIRS 171999]). 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 A-32 November 2004 
INTENTIONALLY LEFT BLANK 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 November 2004 
APPENDIX B 
LIST OF INDIRECT INPUTS FOR INCLUDED AND EXCLUDED FEPS 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 November 2004 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-1 November 2004 
APPENDIX B 
LIST OF INDIRECT INPUTS FOR INCLUDED AND EXCLUDED FEPS 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Crowe, B.; Perry, F.; Geissman, J.; 
McFadden, L.; Wells, S.; Murrell, M.; 
Poths, J.; Valentine, G.A.; Bowker, L.; 
and Finnegan, K. 1995. Status of 
Volcanism Studies for the Yucca 
Mountain Site Characterization Project. 
LA-12908-MS. Los Alamos, New 
Mexico: Los Alamos National 
Laboratory. 
ACC: HQO.19951115.0017. 
100110 
p. 5-5 Section 
6.2.1.1 
In the Yucca Mountain region, 
there has been episodic, smallvolume 
generation of basaltic 
magma, with <0.5 km3 volume 
generated during Quaternary. This 
is consistent with a waning tectonic 
setting. 
Indirect 
Input 
p. 5-2 and 
Figure 5-1 
Section 
6.2.1.1 
Basaltic magma generated from 
sources at depths ranging from 45 
km to approximately 60 km. 
Indirect 
Input 
pp. 4-1, 4-2 Section 
6.2.1.1 
Significance of advent of basaltic 
magmatism in the Yucca Mountain 
Regions in relation to decline and 
end of crustal-level magmatism 
and indicative of waning tectonic 
source 
Indirect 
Input 
pp. 5-2, 5-6 Section 
6.2.1.1 
Once basaltic magma is 
segregated, it must move rapidly to 
the surface to avoid solidification 
Indirect 
Input 
Rogers, A.M.; Harmsen, S.C.; and 
Meremonte, M.E. 1987. Evaluation of 
the Seismicity of the Southern Great 
Basin and Its Relationship to the 
Tectonic Framework of the Region. 
Open-File Report 87-408. Denver, 
Colorado: U.S. Geological Survey. 
ACC: HQX.19880315.0004. 
100176 
p. 82 Section 
6.2.1.1 
Low strain rate in vicinity of Yucca 
Mountain 
Indirect 
Input 
Sweetkind, D.S.; Barr, D.L.; Polacsek, 
D.K.; and Anna, L.O. 1997. 
Administrative Report: Integrated 
Fracture Data in Support of Process 
Models, Yucca Mountain, Nevada. 
Milestone SPG32M3. [Las Vegas, 
Nevada]: U.S. Geological Survey. 
ACC: MOL.19971017.0726. 
100183 
Table 21 Section 
6.2.1.10 
Strain exhibited by faults is 
constrained to relatively narrow 
fault zones (Dune Wash, 
Sundance). 
Indirect 
Input 
pp. 67 to 71 Section 
6.2.1.10 
Conclusions for spatial 
relationships of faulting and 
fracturing 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-2 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Whitney, J.W., ed. 1996. 
Seismotectonic Framework and 
Characterization of Faulting at Yucca 
Mountain, Nevada. Milestone 
3GSH100M. Denver, Colorado: U.S. 
Geological Survey. 
ACC: MOL.19970129.0041; 
MOL.19970129.0042; 
MOL.19970129.0043; 
MOL.19970129.0044; 
MOL.19970129.0045; 
MOL.19970129.0046; 
MOL.19970129.0047; 
MOL.19970129.0048; 
MOL.19970129.0049; 
MOL.19970129.0050; 
MOL.19970129.0051; 
MOL.19970129.0052; 
MOL.19970129.0053; 
MOL.19970129.0054; 
MOL.19970129.0055; 
MOL.19970129.0056; 
MOL.19970129.0057; 
MOL.19970129.0058; 
MOL.19970129.0059; 
MOL.19970129.0060; 
MOL.19970129.0061; 
MOL.19970129.0062. 
100188 
Entire Section 
6.2.1.2 
Extensive fault characterization at 
YM 
Indirect 
Input 
CRWMS M&O 1998. Disruptive 
Events. Chapter 10 of Total System 
Performance Assessment-Viability 
Assessment (TSPA-VA) Analyses 
Technical Basis Document. 
B00000000-01717-4301-00010 REV 
01. Las Vegas, Nevada: CRWMS 
M&O. ACC: MOL.19981008.0010. 
100369 
Section 10.4.4 Sections 
6.2.2.1, 
6.2.2.9 
An early analysis of the effect of a 
dike on flow in the SZ was 
conducted and documented. 
Indirect 
Input 
Section 10.5.3 Sections 
6.2.1.10, 
6.2.1.11 
Corroboration of negligible impact 
on performance from change of 
fault properties for TSPA-VA SZ 
flow models 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-3 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Gauthier, J.H.; Wilson, M.L.; Borns, 
D.J.; and Arnold, B.W. 1996. Impacts 
of Seismic Activity on Long-Term 
Repository Performance at Yucca 
Mountain. Proceedings of the Topical 
Meeting on Methods of Seismic 
Hazards Evaluation, Focus 95, 
September 18-20, 1995, Las Vegas, 
Nevada. Pages 159-168. La Grange 
Park, Illinois: American Nuclear 
Society. TIC: 232628. 
100447 
p. 163 Sections 
6.2.1.9, 
6.2.1.10 
Redistribution of strain could open 
new fractures and close some 
existing fractures 
Indirect 
Input 
pp. 163 - 164 Sections 
6.2.1.1, 
6.2.1.8, 
6.2.1.10, 
6.2.1.11 
Seismically induced water table 
excursions (seismic pumping) 
caused by poroelastic coupling 
would not influence the models 
used for TSPA-VA. 
Indirect 
Input 
p. 164 Section 
6.2.1.1 
Maximum water-table rise was 50 
m within 1 hr of simulated seismic 
event. 
Indirect 
Input 
p. 164 6.2.1.8 Greatest strain-induced changes in 
water table elevation associated 
with strike-slip faults. 
Indirect 
Input 
Stock, J.M. and Healy, J.H. 1988. 
Stress Field at Yucca Mountain, 
Nevada. Chapter 6 of Geologic and 
Hydrologic Investigations of a Potential 
Nuclear Waste Disposal Site at Yucca 
Mountain, Southern Nevada. Carr, M.D. 
and Yount, J.C., eds. Bulletin 1790. 
Denver, Colorado: U.S. Geological 
Survey. TIC: 203085. 
101022 
p. 92 Section 
6.2.1.2 
General reference for source of in 
situ measurements, in support of 
assertion that faults at YM are 
weak and at the point of failure 
Indirect 
Input 
Stock, J.M.; Healy, J.H.; Hickman, S.H.; 
and Zoback, M.D. 1985. Hydraulic 
Fracturing Stress Measurements at 
Yucca Mountain, Nevada, and 
Relationship to the Regional Stress 
Field. Journal of Geophysical 
Research, 90, (B10), 8691-8706. 
Washington, D.C.: American 
Geophysical Union. TIC: 219009. 
101027 
p. 8705 Section 
6.2.1.2 
Pre-existing faults likely to slip 
under increased stress loads 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-4 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Ramelli, A.R.; Oswald, J.A.; Vadurro, 
G.; Menges, C.M.; and Paces, J.B. 
1996. Quaternary Faulting on the 
Solitario Canyon Fault. Chapter 4.7 of 
Seismotectonic Framework and 
Characterization of Faulting at Yucca 
Mountain, Nevada. Whitney, J.W., ed. 
Milestone 3GSH100M. Denver, 
Colorado: U.S. Geological Survey. 
TIC: 237980. 
ACC: MOL.19970129.0041. 
101106 
Table 4.7.3 Section 
6.2.1.10 
Mid to late Quaternary offsets, the 
largest may be as much as 130 
cm, occurred at 70-80 Ka 
Indirect 
Input 
OBrien, G.M. 1993. Earthquake- 
Induced Water-Level Fluctuations at 
Yucca Mountain, Nevada, June 1992. 
Open-File Report 93-73. Denver, 
Colorado: U.S. Geological Survey. 
ACC: NNA.19930326.0022. 
101276 
Entire Section 
6.2.1.8 
Earthquake-induced water level 
changes at YM. 
Indirect 
Input 
Byers, F.M., Jr. and Barnes, H. 1967. 
Geologic Map of the Paiute Ridge 
Quadrangle, Nye and Lincoln Counties, 
Nevada. Map GQ-577. Washington, 
D.C.: U.S. Geological Survey. 
ACC: HQS.19880517.1104. 
101859 
Entire Sections 
6.2.2.1, 
6.2.2.9 
Descriptions of Paiute Ridge dike 
complex and use as analogue 
Indirect 
Input 
Bohannon, R.G. and Parsons, T. 1995. 
Tectonic Implications of Post-30 Ma 
Pacific and North American Relative 
Plate Motions. Geological Society of 
America Bulletin, 107, (8), 937-959. 
Boulder, Colorado: Geological Society 
of America. TIC: 233033. 
101865 
p. 957 Section 
6.2.1.1 
Reference for conditions resulting 
in rapid change of geothermal 
gradient and a weakened 
subducting slab 
Indirect 
Input 
Dixon, T.H.; Robaudo, S.; Lee, J.; and 
Reheis, M.C. 1995. Constraints on 
Present-Day Basin and Range 
Deformation from Space Geodesy. 
Tectonics, 14, (4), 755-772. 
Washington, D.C.: American 
Geophysical Union. TIC: 234271. 
102793 
p. 765 Section 
6.2.1.1 
Locus of tectonic activity has 
moved west of YM. 
Indirect 
Input 
Wernicke, B.; Davis, J.L.; Bennett, 
R.A.; Elosegui, P.; Abolins, M.J.; Brady, 
R.J.; House, M.A.; Niemi, N.A.; and 
Snow, J.K. 1998. Anomalous Strain 
Accumulation in the Yucca Mountain 
Area, Nevada. Science, 279, 2096- 
2100. New York, New York: American 
Association for the Advancement of 
Science. TIC: 235956. 
103485 
Entire Section 
6.2.1.1 
Summary of strain-rate data in the 
Yucca Mountain area 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-5 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Savage, J.C.; Lisowski, M.; Svarc, J.L.; 
and Gross, W.K. 1995. Strain 
Accumulation Across the Central 
Nevada Seismic Zone, 1973-1994. 
Journal of Geophysical Research, 100, 
(B10), 20,257 to 20,269. Washington, 
D.C.: American Geophysical Union. 
TIC: 236811. 
104553 
p. 20263 Section 
6.2.1.1 
Central Nevada Seismic Zone 
(now referred to as part of the 
Intermountain seismic belt) located 
generally north of 37N 
Indirect 
Input 
p. 20263, 
Figure 9 
Section 
6.2.1.1 
YM and its setting have a lower 
strain rate than adjacent seismic 
belts 
Indirect 
Input 
Fridrich, C.J.; Whitney, J.W.; Hudson, 
M.R.; Keefer, W.R.; and Crowe, B.M. 
1996. Space-Time Patterns of 
Extension, Vertical-Axis Rotation, and 
Volcanism in the Crater Flat Basin. 
Chapter 2.II of Seismotectonic 
Framework and Characterization of 
Faulting at Yucca Mountain, Nevada. 
Whitney, J.W., ed. Milestone 
3GSH100M. Denver, Colorado: U.S. 
Geological Survey. TIC: 237980. 
ACC: MOL.19970129.0041. 
105086 
pp. 2-21, 2-22 Section 
6.2.1.1 
Corroboration of PSHA view that 
the majority of future strain will be 
accommodated on block-bounding 
faults by a critical tilting angle of 
approximately 25. 
Indirect 
Input 
Wohletz, K. and Heiken, G. 1992. 
Volcanology and Geothermal Energy. 
Berkeley, California: University of 
California Press. TIC: 241603. 
105544 
pp. 85-154 Section 
6.2.2.5 
Description of a hydrovolcanic 
event 
Indirect 
Input 
Parsons, T.; Thompson, G.A.; and 
Sleep, N.H. 1994. Mantle Plume 
Influence on the Neogene Uplift and 
Extension of the U.S. Western 
Cordillera? Geology, 22, 83-86. 
Boulder, Colorado: Geological Society 
of America. TIC: 233034. 
106479 
p. 83 Section 
6.2.1.1 
General reference - description of 
conditions needed to create a rapid 
change in geothermal gradient - 
hot spot 
Indirect 
Input 
Sweetkind, D.S.; Potter, C.J.; and 
Verbeek, E.R. 1996. Interaction 
Between Faults and the Fracture 
Network at Yucca Mountain, Nevada. 
Eos Transactions, S266. Washington, 
D.C.: American Geophysical Union. 
TIC: 236789. 
106957 
Entire Section 
6.2.1.11 
Observations regarding evidence 
for reactivation of joints 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-6 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Ferrill, D.A.; Winterle, J.; Wittmeyer, G.; 
Sims, D.; Colton, S.; Armstrong, A.; and 
Morris, A.P. 1999. Stressed Rock 
Strains Groundwater at Yucca 
Mountain, Nevada. GSA Today, 9, (5), 
1-8. Boulder, Colorado: Geological 
Society of America. TIC: 246229. 
118941 
p. 1 Section 
6.2.2.1, 
6.2.2.9 
Fault and fracture orientation and 
direction of anisotropic maximum 
transmissivity. 
Indirect 
Input 
Fridrich, C.J. 1999. Tectonic Evolution 
of the Crater Flat Basin, Yucca 
Mountain Region, Nevada. Chapter 7 
of Cenozoic Basins of the Death Valley 
Region. Wright, L.A. and Troxel, B.W., 
eds. Special Paper 333. Boulder, 
Colorado: Geological Society of 
America. TIC: 248054. 
118942 
p. 191 Section 
6.2.1.1 
Activity at regional scale evolving 
westward through episodes of 
activity. 
Indirect 
Input 
p. 189 Section 
6.2.1.1 
Locus of tectonic activity has 
moved west of Yucca Mountain. 
Indirect 
Input 
p. 190 Section 
6.2.1.1 
Reference for information on 
lengthening rate for Crater Flat 
Basin and its relation to other parts 
of Yucca Mountain vicinity. 
Indirect 
Input 
Savage, J.C.; Svarc, J.L.; and Prescott, 
W.H. 1999. Strain Accumulation at 
Yucca Mountain, Nevada, 1983-1998. 
Journal of Geophysical Research, 104, 
(B8), 17627-17631. Washington, D.C.: 
American Geophysical Union. 
TIC: 245645. 
118952 
p. 17627 Section 
6.2.1.1 
YM and its setting (Crater Flat 
domain) have a low strain rate (< 2 
mm/yr) 
Indirect 
Input 
Entire Sections 
6.2.1.1; 
6.2.1.11 
General reference - strain 
accumulation rates 
Indirect 
Input 
Smith, R.P.; Jackson, S.M.; and 
Hackett, W.R. 1998. Magma Intrusion 
and Seismic-Hazards Assessment in 
the Basin and Range Province. 
Proceedings Volume, Basin and Range 
Province (BRP) Seismic-Hazards 
Summit, Reno, Nevada, May 13-15, 
1997. Miscellaneous Publication 98-2, 
155-166. Salt Lake City, Utah: Utah 
Geological Survey. TIC: 246749. 
118967 
p. 158 Section 
6.2.1.7 
Eruption/intrusion commonly 
preceded by swarms of lowmagnitude 
earthquakes around 
and above the propagating dike 
Indirect 
Input 
Table 1 Section 
6.2.1.7 
Maximum magnitude of 
volcanogenic earthquake due to 
dike intrusion is generally less than 
5.0 with a mean of 3.8 +/- 0.8 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-7 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
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Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Stuckless, J.S. 1996. Current Status of 
Paleohydrologic Studies at Yucca 
Mountain and Vicinity, Nevada. High 
Level Radioactive Waste Management, 
Proceedings of the Seventh Annual 
International Conference, Las Vegas, 
Nevada, April 29-May 3, 1996. 98-101. 
La Grange Park, Illinois: American 
Nuclear Society. TIC: 226494. 
119051 
pp. 98 - 99 Section 
6.2.1.1 
Excursions of the water table in 
Plio-Pliestocene time is estimated 
to be about 115 m or less 
Indirect 
Input 
Thatcher, W.; Foulger, G.R.; Julian, 
B.R.; Svarc, J.; Quilty, E.; and Bawden, 
G.W. 1999. Present-Day Deformation 
Across the Basin and Range Province, 
Western United States. Science, 283, 
(5408), 1714-1718. Washington, D.C.: 
American Association for the 
Advancement of Science. 
TIC: 246227. 
119053 
pp. 1714 and 
1715 
Section 
6.2.1.1 
Tectonic activity at regional scale 
is typically concentrated in zones 
or belts tens to 100s kms wide 
Indirect 
Input 
pp. 1714 and 
1715 
Section 
6.2.1.1 
Seismic belts characterized by 
high geodetic strain rates and 
recurrent earthquakes 
Indirect 
Input 
Day, W.C.; Potter, C.J.; Sweetkind, 
D.S.; Dickerson, R.P.; and Keefer, 
W.R. 1996. Structural Geology of the 
Central Block of Yucca Mountain. 
Chapter 2-I of Seismotectonic 
Framework and Characterization of 
Faulting at Yucca Mountain, Nevada. 
Whitney, J.W., ed. Milestone 
3GSH100M. Denver, Colorado: U.S. 
Geological Survey. TIC: 237980. 
ACC: MOL.19970129.0041. 
124302 
p. 2-7 Section 
6.2.1.1 
For Bow Ridge fault flattening 
foliations in faulted tuffs dip steeply 
to east (20-30 degrees) into the 
graben(s) relative to beds further to 
the west in the unfaulted areas 
(which dip 8 to 15 degrees). 
Indirect 
Input 
NRC (U.S. Nuclear Regulatory 
Commission) 1999. Issue Resolution 
Status Report Key Technical Issue: 
Structural Deformation and Seismicity. 
Rev. 2. Washington, D.C.: U.S. Nuclear 
Regulatory Commission. 
ACC: MOL.19991214.0623. 
135621 
p. 55 Section 
6.2.1.11 
NRC description of fracturing Indirect 
Input 
Connor, C.B.; Stamatakos, J.; Ferrill, 
D.; Hill, B.E.; Magsino, S.B.L.; La 
Femina, P.; and Martin, R.H. 1996. 
Integrating Structural Models into 
Probabilistic Volcanic Hazard Analyses: 
An Example from Yucca Mountain, 
NV. Abstracts with Programs - 
Geological Society of America, 28, (7), 
A-192. Boulder, Colorado: Geological 
Society of America. TIC: 247409. 
135969 
p. 78 Sections 
6.2.2.1, 
6.2.2.9 
Factors affecting dike orientation 
and vent alignment 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-8 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Wohletz, K.H. 1986. Explosive 
Magma-Water Interactions: 
Thermodynamics, Explosion 
Mechanisms, and Field Studies. 
Bulletin of Volcanology, 48, 245-264. 
Berlin, Germany: Springer-Verlag. 
TIC: 225183. 
140956 
p. 262 Section 
6.2.2.5 
At the Lathrop Wells volcano, there 
are currently no field data 
indicating a concentric 
hydrovolcanic facies tuff ring 
Indirect 
Input 
Lachenbruch, A.H. and Sass, J.H. 
1978. Models of an Extending 
Lithosphere and Heat Flow in the Basin 
and Range Province. Chapter 9 of 
Cenozoic Tectonics and Regional 
Geophysics of the Western Cordillera. 
Smith, R.B. and Eaton, G.P., eds. 
Memoir 152. Pages 209-250. Boulder, 
Colorado: Geological Society of 
America. TIC: 225059. 
142990 
pp. 212 and 
246 
Section 
6.2.1.1 
YM lies south of regions of 
relatively high crustal heat flow in 
the Great Basin that are thought to 
indicate latent tectonism. 
Indirect 
Input 
pp. 224 and 
244 
Section 
6.2.1.1 
Geothermal gradient could be 
steepened by large volume of 
magma emplaced in the mid to 
upper crust (approximately 5 km). 
Indirect 
Input 
Mongano, G.S.; Singleton, W.L.; 
Moyer, T.C.; Beason, S.C.; Eatman, 
G.L.W.; Albin, A.L.; and Lung, R.C. 
1999. Geology of the ECRB Cross Drift 
- Exploratory Studies Facility, Yucca 
Mountain Project, Yucca Mountain, 
Nevada. [Deliverable SPG42GM3]. 
Denver, Colorado: U.S. Geological 
Survey. ACC: MOL.20000324.0614. 
149850 
Entire Section 
6.2.1.10 
Observations of width of brecciated 
zones and fracture frequencies in 
vicinity of faults. 
Indirect 
Input 
pp. 59-65 Section 
6.2.1.10 
In the Solitario Canyon fault zone 
in the ECRB Cross Drift, the total 
displacement is approximately 260 
m, but the gouge and brecciated 
zones are limited to less than 20 m 
from the main fault trace. 
Indirect 
Input 
pp. 52-54 Section 
6.2.1.10 
The Sundance fault has a 
presumed, though indeterminate, 
displacement of several meters. 
However, the footwall rock is intact 
at a distance of only 10 cm from 
the fault plane. The hanging wall of 
the Sundance fault is slightly more 
fractured, having an intensely 
fractured zone about 1-m thick. 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-9 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Wilson, S.F. and Cline, J.S. 2001. 
Paragenesis, Temperature and Timing 
of Secondary Minerals at Yucca 
Mountain. Back to the Future - 
Managing the Back End of the Nuclear 
Fuel Cycle to Create a More Secure 
Energy Future, Proceedings of the 9th 
International High-Level Radioactive 
Waste Management Conference 
(IHLRWM), Las Vegas, Nevada, April 
29-May 3, 2001. La Grange Park, 
Illinois: American Nuclear Society. 
TIC: 247873. 
155426 
Entire Section 
6.2.1.1 
Results of a two-year study at 
UNLV concluded that hydrothermal 
water has not invaded Yucca 
Mountain in the last 2 m.y 
Indirect 
Input 
DOE (U.S. Department of Energy) 
2002. Final Environmental Impact 
Statement for a Geologic Repository for 
the Disposal of Spent Nuclear Fuel and 
High-Level Radioactive Waste at Yucca 
Mountain, Nye County, Nevada. 
DOE/EIS-0250. Washington, D.C.: U.S. 
Department of Energy, Office of Civilian 
Radioactive Waste Management. 
ACC: MOL.20020524.0314; 
MOL.20020524.0315; 
MOL.20020524.0316; 
MOL.20020524.0317; 
MOL.20020524.0318; 
MOL.20020524.0319; 
MOL.20020524.0320. 
155970 
p. 3-59 Sections 
6.2.1.8, C1.1 
Results of National Research 
Council consideration of seismic 
pumping phenomenon 
Indirect 
Input 
Carter Krogh, K.E. and Valentine, G.A. 
1996. Structural Control on Basaltic 
Dike and Sill Emplacement, Paiute 
Ridge Mafic Intrusion Complex, 
Southern Nevada. LA-13157-MS. Los 
Alamos, New Mexico: Los Alamos 
National Laboratories. 
ACC: MOL.20030828.0138. 
160928 
pp. 7 and 8 Sections 
6.2.2.1, 
6.2.2.4, 
6.2.2.9, C2.2 
Description of dikes and dike 
margins of the Paiute Ridge dike 
complex. 
Indirect 
Input 
Williams, N.H. 2001. Contract No. DEAC08-
01RW12101 - KTI Deliverable to 
NRC - October 2001. Letter from N.H. 
Williams (BSC) to S.J. Brocoum 
(DOE/YMSCO), October 16, 2001, 
1012010135, LTS:cdg, with enclosures. 
ACC: MOL.20020206.0018. 
161728 
Entire Section 6.1.2 Statement of DOE intent to use 
mean, rather than median values, 
for DE FEP screening 
Indirect 
Input 
Fisher, R.V. and Schmincke, H.-U. 
1984. Pyroclastic Rocks. New York, 
New York: Springer-Verlag. 
TIC: 223562. 
162806 
pp. 231-264 Section 
6.2.2.5 
Description of a hydrovolcanic 
event 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-10 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
NRC (U.S. Nuclear Regulatory 
Commission) 2003. Yucca Mountain 
Review Plan, Final Report. NUREG- 
1804, Rev. 2. Washington, D.C.: U.S. 
Nuclear Regulatory Commission, Office 
of Nuclear Material Safety and 
Safeguards. TIC: 254568. 
163274 
Section 
2.2.1.2.1.3, 
criterion 2 
Section 4.2.3 Allows for exclusion of a FEP is the 
process is specifically excluded by 
the regulations. 
Indirect 
Input 
Glossary Section 6.1 Definitions used by FEPs analysis. Indirect 
Input 
Section 2.2.1 Section 4.2.3 Technical basis for simplified 
approaches to a complex analysis. 
Indirect 
Input 
Section 
2.2.1.2 
Section 4.2.2 The basis of the NRC license 
application review is given. 
Indirect 
Input 
Sections 
2.2.1.2.1.3 
and 
2.2.1.2.2.3 
Sections 4.2, 
4.2.1; Table 7- 
2 
Pertinent sections of NRC Yucca 
Mountain Review Plan that pertain 
to FEPs requirements as related to 
scenario development and analysis 
Indirect 
Input 
Section 
2.2.1.2.1.3, 
criteria 1 and 
2; Section 
2.2.1.2.2.3, 
criteria 1, 2, 
and 5 
Tables 4-2, 4- 
3; Sections 
6.1.1; 6.1.2 
NRC acceptance criteria for FEPs Indirect 
Input 
Rojstaczer, S. 1991. Elastic 
Deformation as a Second Order 
Influence on Groundwater Flow in 
Areas of Crustal Unrest. Eos 
Transactions (Supplement), 72, (17), 
[N/A]. [Washington, D.C.]: American 
Geophysical Union. TIC: 216706. 
163416 
Abstract Section 
6.2.2.9 
For a dike initially intruding into the 
SZ, a possible rise in the water 
table of only a few tens of meters 
is indicated. 
Indirect 
Input 
Woods, A.W.; Sparks, S.; Bokhove, O.; 
LeJeune, A-M.; Conner, C.B.; and Hill, 
B.E. 2002. Modeling Magma-Drift 
Interaction at the Proposed High-Level 
Radioactive Waste Repository at Yucca 
Mountain, Nevada, USA. Geophysical 
Research Letters, 29, (13), 19-1 
through 19-4. [Washington, D.C.]: 
American Geophysical Union. 
TIC: 254467. 
163662 
Entire Sections 
6.2.2.6 
Reference for the dog-leg 
alternative conceptual model 
Indirect 
Input 
Bates, R.L. and Jackson, J.A., eds. 
1987. Glossary of Geology. 3rd Edition. 
Alexandria, Virginia: American 
Geological Institute. TIC: 8832. 
164050 
p. 257 Section 
6.2.1.11 
Definition of fracture Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-11 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Fridrich, C.J.; Whitney, J.W.; Hudson, 
M.R.; and Crowe, B.M. 1998. Space- 
Time Patterns of Late Cenozoic 
Extension, Vertical-Axis Rotation, and 
Volcanism in the Crater Flat Basin, 
Southwest Nevada. Open-File Report 
98-461. Denver, Colorado: U.S. 
Geological Survey. 
ACC: MOL.19981014.0299. 
164051 
pp. 1 and 2 Section 
6.2.1.1 
Rate of tectonism has decreased 
greatly since late Miocene. 
Indirect 
Input 
pp. 1, 2, 13, 
19, 20 
Section 
6.2.1.1 
Rates of extension through time. Indirect 
Input 
Canori, G.F. and Leitner, M.M. 2003. 
Project Requirements Document. TERMGR-
MD-000001 REV 02. Las Vegas, 
Nevada: Bechtel SAIC Company. 
ACC: DOC.20031222.0006. 
166275 
PRD-002/ T- 
015 and PRD- 
002/T-034 
Table 4-2 Project requirements applicable to 
FEPs screening and analysis 
Indirect 
Input 
Entire Sections 4.2, 
4.2.1 
General reference to project 
requirements document 
Indirect 
Input 
BSC (Bechtel SAIC Company) 2003. 
Total System Performance 
Assessment-License Application 
Methods and Approach. TDR-WIS-PA- 
000006 REV 00 ICN 01. Las Vegas, 
Nevada: Bechtel SAIC Company. 
ACC: DOC.20031215.0001. 
166296 
Section 2.1 Section 
6.2.2.8 
The ash redistribution calculations 
for a probability weighted volcanic 
event are performed within TSPALA 
using the SoilExp_LA DLL. 
Indirect 
Input 
Section 8.1.2 Sections 
6.2.2.2, 
6.2.2.3, 
6.2.2.6, 
6.2.2.7, 
6.2.2.8 
Outline of TSPA-LA approach for 
the igneous eruptive and 
groundwater models 
Indirect 
Input 
Section 5.2 Section 
6.2.2.2 
The manner in which the igneous 
intrusion is incorporated into the 
TSPA-LA igneous intrusion 
groundwater transport modeling 
case is discussed. 
Indirect 
Input 
BSC (Bechtel SAIC Company) 2004. 
Q-List. 000-30R-MGR0-00500-000-000 
REV 00. Las Vegas, Nevada: Bechtel 
SAIC Company. 
ACC: ENG.20040721.0007. 
168361 
Entire Section 2 The disruptive events FEPs 
documented in this report involve 
the investigations of items or 
barriers on the Q-list. 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-12 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
BSC (Bechtel SAIC Company) 2004. 
The Development of the Total System 
Performance Assessment-License 
Application Features, Events, and 
Processes. TDR-WIS-MD-000003, 
Rev. 01. Las Vegas, Nevada: Bechtel 
SAIC Company. 
168706 
Entire Sections 1.2, 
6.1, 6.1.6, 7 
Describes the TSPA-LA FEP 
identification and screening 
process that led to the 
development of the LA FEP list 
Indirect 
Input 
Section 3 Section 6.1.1 The TSPA-LA FEP identification 
classification process is described. 
Indirect 
Input 
Section 4 Section 6.1.2 The TSPA-LA FEP screening 
process is described. 
Indirect 
Input 
Section 
4.1.3.3 
Section 4.1 Definitions and concepts (e.g., 
RMEI is located no closer than 18 
km to the south in the direction of 
groundwater flow and over a 
contaminated groundwater plume). 
Indirect 
Input 
Section 
4.1.3.2 
Section 4.1 Requirements (e.g., the reference 
biosphere must be consistent with 
present knowledge of conditions in 
the region, and changes in the 
biosphere [other than climate] from 
conditions at the time of license 
application submittal should not be 
projected. Also, the geologic 
setting [geology, hydrology, and 
climate] may evolve based upon 
cautious but reasonable 
assumptions, consistent with 
present knowledge of factors that 
could affect the system in the next 
10,000 years). 
Indirect 
Input 
Section 4.1.3 Section 4.1 Regulatory definitions and 
elucidation of the regulatory 
concepts pertaining to the 
reference biosphere, geologic 
setting, REMI, and human intrusion 
are explained in detail. 
Indirect 
Input 
Table 6-2 Section 4.1 Subsequent additions to or 
changes from that FEP list 
(numbers, names, or descriptions) 
are reflected in Section 6.2 and 
can be traced through the FEP 
History File in the FEP database. 
Indirect 
Input 
BSC (Bechtel SAIC Company) 2004. 
Development of Seismic Inputs, 
Preparation of Seismic Topical Reports, 
and Evaluation of Disruptive Events 
Features, Events, and Processes. 
TWP-MGR-GS-000001 REV 03 ICN 
01. Las Vegas, Nevada: Bechtel SAIC 
Company. ACC: DOC.20040601.0001. 
169886 
Section 8.1 Section 2, 
Section 4.2 
Applicable controls for the 
electronic management of data 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-13 November 2004 
Table B-1. Table of Indirect Inputs for Included and Excluded Features, Events, and Processes (Continued) 
Document Source 
Citation 
from 
Source 
Direct Use 
In Description 
Input 
Category 
Entire Section 1.1 General reference to the 
controlling planning document 
Indirect 
Input 
Sections 4.1, 
8.1 
Section 2 Applicable QA procedures Indirect 
Input 
BSC (Bechtel SAIC Company) 2004. 
Engineered Barrier System Features, 
Events, and Processes. ANL-WIS-PA- 
000002, Rev. 03. Las Vegas, Nevada: 
Bechtel SAIC Company. 
169898 
Entire Sections 
6.2.1.2, 
6.2.1.3, 
6.2.1.6 
Fault displacement - shared FEP 
seismic consequence fault 
displacement and ground motion. 
Indirect 
Input 
BSC (Bechtel SAIC Company). 
Qualification of Igneous Inputs to 
Features, Events, and Processes: 
Disruptive Events. TDR-WIS-PA- 
000013 REV 00. Las Vegas, Nevada: 
Bechtel SAIC Company. 171999 
Entire Section 6.1.4 Qualification of extent of volcanic 
surge deposits. 
Indirect 
Input 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 B-14 November 2004 
INTENTIONALLY LEFT BLANK 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 November 2004 
APPENDIX C 
QUALIFICATION OF EXTERNAL SOURCES 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 November 2004 

Features, Events, and Processes: Disruptive Events 
ANL-WIS-MD-000005 REV 02 C-1 November 2004 
APPENDIX C 
QUALIFICATION OF EXTERNAL SOURCES 
Per AP-SIII.9Q, Scientific Analyses, this appendix documents the justification of the following 
reference identified as direct input in this report (see Appendix A, Table A-1). The National 
Research Council (1992 [DIRS 105162) is identified as unqualified data from an outside source. 
These data are qualified in this appendix for intended use per criteria in AP-SIII.9Q 
(Section 5.2.1 l). 
NATIONAL RESEARCH COUNCIL 1992 
ReferenceNational Research Council. 1992. Ground Water at Yucca Mountain, How High 
Can It Rise? Final Report of the Panel on Coupled Hydrologic/Tectonic/Hydrothermal 
Systems at Yucca Mountain. Washington, D.C.: National Academy Press. TIC: 204931. 
DIRS: 105162]. 
Description of UseThe National Research Council (1992 [DIRS 105162]) reference provides 
the basis for excluding the FEP related to potential water level rise due to seismic pumping. 
Alternative perspectives on seismic pumping and water-level changes are discussed in the Final 
Environmental Impact Statement (DOE 2002, p. 3-59 [DIRS 155970]), which cites the work by 
the National Research Council. The panel reviewed the alternative conceptual model and 
concluded that it was infeasible. 
Extent to which the Data Demonstrate the Properties of InterestSeismic pumping and 
water-level changes are discussed in a report prepared by the Panel on Coupled 
Hydrologic/Tectonic/Hydrothermal Systems at Yucca Mountain, commissioned by the National 
Research Council (NRC). The panel reviewed an alternative conceptual model that predicted 
large changes in water level, and concluded that it was infeasible. The panel went on to state that 
seismic pumping would at most elevate the water-levels a few tens of meters (Ground Water at 
Yucca Mountain: How High Can It Rise? Page 7). 
Qualifications of Personnel or Organizations Generating DataThe project that is the subject 
of this report was approved by the Governing board of the National Research Council, whose 
members are drawn from the councils of the National Academy of Sciences, the National 
Academy of Engineering, and the Institute of Medicine. The members of the committee 
responsible for the report were chosen for their special competences and with regard for 
appropriate balance. This report has been reviewed by a group other than the authors according 
to procedures approved by a Report Review Committee consisting of members of the National 
Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. 
Panel On Coupled Processes At Yucca Mountain: 
C. Barry Raleigh, University Of Hawaii, Chairman 
George A. Thompson, Stanford University, Vice-Chairman 
William F. Brace, Massachusetts Institute Of Technology (Ret.) 
Barry H. G. Brady, Dowell-Schlumberger 
John D. Bredehoeft, U. S. Geological Survey 
Raymond M. Burke, Humboldt State University 

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Robert O. Fournier, U. S. Geological Survey 
Sabodh K. Garg, S-Cubed 
George M. Hornberger, University Of Virginia 
Robin K. Mcguire, Risk Engineering, Inc. 
Amos M. Nur, Stanford University 
H. J. Ramey, Stanford University 
Edwin W. Roedder, Harvard University 
Douglas Rumble, Geophysical Laboratory, Carnegie Institution Of Washington 
W. Geoffrey Spaulding, Dames & Moore 
Brian P. Wernicke, California Institute Of Technology 
Mary Lou Zoback, U. S. Geological Survey 
Reliability of Data SourceThe report was published by the National Academies Press (NAP). 
The National Academies Press was created by the National Academies to publish the reports 
issued by the National Academy of Sciences, the National Academy of Engineering, the Institute 
of Medicine, and the National Research Council, all operating under a charter granted by the 
Congress of the United States. NAP publishes over 200 books a year on a wide range of topics 
in science, engineering, and health, capturing the most authoritative views on important issues in 
science and health policy. The institutions represented by NAP are unique because they attract 
the nation's leading experts in every field to serve on their blue ribbon panels and committees. 
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of 
distinguished scholars engaged in scientific and engineering research and dedicated to the 
furtherance of science and technology and to their use for the general welfare. Upon the 
authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that 
requires it to advise the federal government on scientific and technical matters. 
The National Research Council was organized by the National Academy of Sciences in 1916 to 
associate the broad community of science and technology with the Academy's purposes of 
furthering knowledge and of advising the federal government. Functioning in accordance with 
general policies determined by the Academy, the Council has become the principal operating 
agency of both the National Academy of Sciences and the National Academy of Engineering in 
providing services to the government, the public, and the scientific and engineering 
communities. The Council is administered jointly by both Academies and the Institute of 
Medicine. 

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APPENDIX D 
GLOSSARY 

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APPENDIX D 
GLOSSARY 
annual exceedance probabilityThe probability that a specified value (such as for ground 
motions or fault displacement) will be exceeded during one year. 
apertureThe gap between two walls or faces of a fracture. 
ash flowA density current, generally a hot mixture of volcanic gases and tephra that travels 
across the ground surface. The solid materials contained in a typical ash flow are generally 
unsorted and ordinarily include volcanic dust, pumice, scoria, and blocks in addition to ash. 
ash fallAirborne ash that falls from an eruption cloud, and the resulting deposit. 
asperityA measure of the roughness of the area of contact between two surfaces of a fracture. 
background earthquakeAn earthquake that does not produce ground breakage, hence is not 
associated with a known fault. Such earthquakes are considered to be random in time and space. 
In the Great Basin, background earthquakes have magnitudes of less than 6.0. 
basaltA dark-colored, fine-grained volcanic or intrusive rock (dike or sill intrusion) consisting 
chiefly of calcic plagioclase, pyroxene, and olivine. 
base levelThe theoretical lowest level toward which erosion progresses, considered practically 
as the level below which a stream cannot erode its bed. 
blind faultA fault that dies out in bedrock and is not exposed at earths surface. 
block faultingSegmentation of the crust into block-like masses by systematic normal faulting. 
caldera complexAn assemblage of extrusive and intrusive rocks and associated structures 
generated by explosive and effusive volcanism that comprise a number of genetically related 
overlapping or adjacent or proximal calderas. 
calicheA calcareous soil component typically forming friable to hard, off-white, crudely 
layered to finely laminated intervals near the surface of stony desert soils; several cm or more 
thick. Old, thick caliche intervals (calcretes) have the texture and hardness of concrete 
aggregate. 
colluvial slopeA hill slope mantled with loose, heterogeneous soil and rock fragments that are 
the result of weathering and accumulation by creep and unchanneled snow melt or runoff. 
conduitThe vertical or subvertical, essentially cylindrical, tube that brings magmatic material to 
land surface. Conduit is the appropriate term regarding the subsurface, and PA conceptual 
models emphasize the interactions that occur at the intersection of a conduit with the repository. 
Crater Flat tectonic domainA tectonic domain is a block of the Earths crust bounded by 
major faults or zones of complex shear and deformation. A domain features a history and styles 

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of deformation that distinguish it from adjacent areas of the crust. The Crater Flat domain 
includes Yucca Mountain and is characterized by normal faulting into the Crater Flat basin 
which lies immediately to the west of Yucca Mountain. 
debris flowA moving mass of rock fragments and mud, comprised mostly of fragments larger 
than sand size; water-mobilized colluvium; also the deposit of such a flow. 
detachment faultingA style of normal faulting wherein large, extensional displacement occurs 
on a fault plane that dips less than 30. In places, the lower plates (footwalls) of detachment 
faults have been uplifted from mid-crustal depths, implying that detachment is accompanied by 
significant isostatic uplift or uplift by magmatic inflation. 
dikeA tabular intrusion of magma that is at a high angle to layering in the intruded strata 
(i.e., vertical or subvertical at Yucca Mountain). 
dike systemOne or more dikes that are closely related in space and time. Dike systems may 
include multiple dikes that share a common magmatic source with a single volcano. This 
definition does not preclude the possibility that a dike system may feed more than one volcano. 
dip-slip faultingFaulting in which the hanging wall moves down the dip of the fault plane. 
Normal faulting has slip directly along the dip normal to the strike of the fault; oblique faulting 
has a component of slip parallel to the fault strike (i.e., some lateral displacement). 
disruptive FEPAn Included FEP that has a probability of occurrence during the period of 
performance less than 1.0 (but greater than the cutoff of 10-4/104 year). 
disruptive event scenario classThe scenario class, or set of related scenarios classes, that 
describes the behavior of the system if perturbed by disruptive events. The disruptive scenario 
classes contain all disruptive FEPs that have been retained for analysis. 
eruptive event (with respect to repository performance)The formation of a volcano that 
includes at least one subsurface conduit that intersects a drift containing waste packages. 
eventA natural or human-caused phenomenon that has the potential to affect disposal-system 
performance and that occurs during an interval that is short compared to the period of 
performance. 
Excluded FEPA FEP that is identified by the FEP screening process as not requiring modeling 
in the quantitative TSPA. 
expected FEPAn Included FEP that, for the purposes of the TSPA, is presumed to occur with a 
probability equal to 1.0 during the period of performance. 
extrusive event (with respect to repository performance)Synonymous with eruptive event. 
faultingProcess of fracture and attendant slip along a fracture plane or recurrent slip along such 
a plane. 

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fault strandA fault segment expressed as a continuous intersection with the earths surface, as 
indicated by a scarp, scarp line, or series of exposed displacement features, all having the same 
style of offset. A fault strand is generally taken to connote a relatively short fault segment or 
splay that is one of a series of many faults that together form the principal fault zone. The 
zone is usually not straight and well developed, and faults may bifurcate or anastomose or step 
over from one fault to another. Slip can be transferred across many strands. 
featureAn object, structure, or condition that has a potential to affect disposal-system 
performance. 
flowing intervalA fracture or fractured zone that transmits flow in the SZ. 
foldingBending in strata. Formation of folds expressed by geometric features that include fold 
limbs, fold axes, and axial planes. Large or systematic compressive and drag folds are results of 
tectonic activity. 
fractureA brittle crack in rock. Groups of fractures in more or less regular orientation and 
spacing are termed joints. Fractures form by bending (shear joints) or tension or principal stress 
reduction (extension joints). Cooling joints are formed by tension exerted by contraction as an 
intrusive or extrusive volcanic rock cools. 
futureA single, deterministic representation of the future state of the system. An essentially 
infinite set of futures can be imagined for any system. 
geodetic strain rateRegional strain rate determined at the earths surface by repeated 
measurement of displacements of precisely located landmarks (monuments) embedded in the 
deforming medium. 
geologic settingThe geologic, hydrologic, and geochemical systems of the region in which a 
geologic repository is or may be located. 
geothermal gradientThe rate of increase of temperature with depth in the earth 
heat flowThe amount of heat energy leaving the earths crust, measured in Heat Flow Units 
(HFU) or calories/m2/sec. 
hydrovolcanic eruptionVery energetic explosive eruptions triggered by the rapid mixing of 
ground or surface water with rising magma eruptions. Rather than formation of scoria cones by 
ballistic deposition, tephra and lithic clasts are deposited as fallout and pyroclastic density 
currents leaving surge deposits and typically forming wide, shallow tuff rings. 
igneous activityAny process associated with the generation, movement, emplacement, or 
cooling of molten rock within the earth or on the earths surface. 
Included FEPA FEP that is identified by the FEP screening process as requiring analysis in the 
quantitative TSPA. 

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intrusive event (with respect to repository performance)An igneous structure (such as a dike, 
dike system, or other magmatic body in the subsurface) that intersects the repository footprint at 
the repository elevation. 
key blockCritical blocks formed in the rock mass surrounding an excavation (by the 
intersection of three or more planes of structural discontinuity). These blocks are capable of 
displacement so that they are likely to move into the drift opening unless restraint is provided. 
lithophysaeA subrounded cavity from about one to several cm in diameter formed in silicic 
volcanic rocks (e.g., welded tuff) by gas bubbles evolved during cooling; lithophysae are 
typically lined or largely filled with finely crystalline or cryptocrystalline rinds of secondary, 
vapor-phase minerals. 
maarA low-relief, broad volcanic crater formed by shallow explosive eruptions. The 
explosions are usually caused by the heating and boiling of groundwater resulting from magma 
invading the groundwater table. 
magmaPartially or completely molten rock within the earths crust or mantle. 
magmatic inflationUplift of the crust caused by intrusion of subjacent magma, which can 
occur due to large-volume batholithic melts, dike swarms, or lower crustal magmatic 
underplating. 
mantleThe zone of the earth below the crust and above the core, typified by high seismic 
velocity and dense iron- and magnesium-rich silicate mineral components. 
mantle plumeA large mass of molten mantle material rising up from the lower mantle into the 
base of the crust by the process of convection and buoyancy. Mantle plumes are typically 
hundreds of km in area. 
MioceneEpoch of the Tertiary Period between 24 Ma and 5 Ma. 
modeling caseA well-defined, connected sequence of FEPs that can be thought of as an outline 
of a future condition of the repository system. Modeling cases can be undisturbed, in which case 
the performance would be the expected, or nominal, behavior for the system. Modeling cases 
can also be disturbed, if altered by disruptive events such as human intrusion or natural 
phenomena such as volcanism, seismicity, or nuclear criticality. 
nominal scenario classThe scenario class, or set of related scenarios classes, that describes the 
expected or nominal behavior of the system as perturbed only by the presence of the repository. 
The nominal scenario class contains all expected FEPs that have been retained for analysis. 
nonwelded unitA volcanic ash, or tuff, that is crumbly or easily excavated because the 
component glass shards did not weld together during compaction of relatively cool ash or ash 
having relatively sparse glass content. 
paleoseismic slipThe amount of fault slip indicated by buried offset strata; individual 
paleoearthquakes are indicated by discrete amounts of offset. 

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percolation flowFlow of groundwater through small, interconnected rock or soil pores. 
playaA dried lake bed. Playas have, typically, a flat, salty surface that forms the low part of a 
confined desert basin. 
PleistoceneThe epoch of the Quaternary Period from about 1.6 Ma to 10 Ka. 
Plio-PleistoceneCombined duration of the Pliocene and Pleistocene epochs of the Cenozoic 
era, from 10 Ka to 5 Ma. 
potentiometric surfaceA notional surface representing the total head of groundwater as 
defined by the level at which such water stands in a well. The water table is a particular type of 
potentiometric surface pertaining to an unconfined aquifer in which the surface is in equilibrium 
with atmospheric pressure. 
processA natural or human-caused phenomenon that has the potential to affect disposal-system 
performance and that operates during all or a significant part of the period of performance. 
pumiceHighly vesicular or frothy siliceous glass formed during volcanic eruption; typically a 
pale gray color. 
pumiceousHaving observable pumice content. 
pyroclasticPertaining to clastic rock material formed by volcanic explosion or aerial expulsion 
from a volcanic vent. 
QuaternaryThe period of the Cenozoic Era from 1.6 Ma to present includes the Pleistocene 
and Holocene Epochs. 
reference biosphereThe description of the environment inhabited by the reasonably maximum 
exposed individual (RMEI). The reference biosphere comprises the set of specific biotic and 
abiotic characteristics of the environment, including but not necessarily limited to, climate, 
topography, soils, flora, fauna, and human activities. 
regional slopeThe surface defined by the elevations of resistant peaks in a given area; it 
approximates the surface formed by uplift prior to erosional incision. 
regional subsidenceBroad depression of the earths surface resulting from tectonic activity 
such as extension, crustal cooling, or deep crustal or mantle flow. 
regional upliftBroad elevation of the earths surface resulting from tectonic activity such as 
compression or igneous intrusion. 
rockburstA sudden and often violent failure of masses of rocks in quarries, tunnels, or mines. 
It is an uncontrolled disruption of rock associated with a violent release of energy additional to 
that derived from falling rock fragments. 

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scenario classA set of related modeling cases that share sufficient similarities that they can 
usefully be aggregated for the purposes of screening or analysis. The number and breadth of 
scenario classes depends on the resolution at which modeling cases have been defined. Coarsely 
defined modeling cases result in fewer, broad scenario classes, whereas narrowly defined 
modeling cases result in many narrow scenario classes. Scenario classes (and modeling cases) 
should be aggregated at the coarsest level at which a technically sound argument can be made, 
while still maintaining adequate detail for the purposes of analysis. 
seismic activityThe recurrence and distribution of earthquakes associated with a specified 
seismic source. 
seismicityThe capacity of a fault, group of faults, or region of the crust to generate earthquakes, 
as determined by instrumental or paleoseismic history; the relative rate at which earthquakes 
recur (syn. seismic activity). 
springlineThe imaginary line at which an arch, vault, or drift begins to curve; for circular 
cross-sections, this corresponds to the vertical mid-point along the drift wall. 
strain rateThe rate at which a unit of length is shortened or lengthened under a stress load, 
usually given in terms of inverse seconds. Strain rate is often expressed in units of mm/yr where 
an actual length difference rather than a ratio is calculated. 
strandSee fault strand. 
stream gradientAngle between inclination of a stream channel bed and the horizontal 
measured in direction of flow (i.e., the slope of a stream). 
subducting slabA section of oceanic (basaltic) crust in process of being drawn down into the 
upper mantle by tectonic forces as crustal plates interact. 
tectonic activityThe dynamic manifestation of stress loads generated within the earths crust 
(e.g., igneous intrusion, earthquakes, uplift). 
tectonic deformationThe suite of geological structures generated by body stresses exerted 
within the earths crust; such structures range in scale from microscopic (e.g., mylonite fabric) to 
regional (e.g., overthrust belts). Also, the process by which such structures together is formed. 
tectonic extensionStretching or extension of the crust as a result of deep-seated tectonic stress, 
such as back-arc spreading. 
tectonic processThe dynamic evolution of structure generated through the buildup and 
relaxation of regional stress. 
tectonismAll movement of the crust produced by tectonic processes, including mountain 
building (orogeny), regional uplift and subsidence; the general expression of tectonic process 
through time and space. 

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tephraA collective term used for all pyroclastic material, regardless of size, shape, or origin, 
ejected during an explosive volcanic eruption. Originally applied exclusively to fallout ejecta, 
but now also applies to pyroclastic flow deposits. 
terrain reliefFor some defined area of the earths surface, it is the measure of difference 
between the lowest local elevation and the highest local elevation. 
topographyThe physical features of a district or region, such as are represented on maps, taken 
collectively; especially the relief and contour of the land. 
Type I faultFaults or fault zones that are subject to displacement and are of sufficient length 
and location that they may affect repository design or performance. 
ventThe intersection of a conduit with land surface. Volcanoes may have more than one vent. 
violent strombolian eruptionvolcanic eruptions with violent blasts that project voluminous 
showers of scoria and bombs to heights of hundreds or thousands of feet, accompanied by a 
dense black ash cloud. Violent strombolian eruptions are characterized by vertical eruption of a 
high-speed jet of a gas-clast mixture. 
volcanic activityThe suite of events and processes associated with extrusion of molten rock, 
such as eruption, lava emission, or cone formation comprising the subaerial components of 
igneous activity. 
volcanic eventThe formation of a volcano (with one or more vents) resulting from the ascent of 
basaltic magma through the crust as a dike or system of dikes. 
volcanoA geologic feature that includes an edifice of magmatic material erupted on the land 
surface, a conduit that feeds the eruption, and a dike that feeds the conduit. 
water tableThe surface of unconfined groundwater at which the pressure is equal to that of the 
atmosphere. 
welded unitA volcanic ash, or tuff, that is strongly indurated because hot glass shards were 
partially melted together (welded) during compaction of the ash bed while the ash was still hot. 

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