Transportation Cask Receipt and Return Facility Worker Dose Assessment Rev 00B, ICN 00

140-00C-CC00-00200-000-00B

February 2005 

 
1. PURPOSE 
The purpose of this design calculation is to estimate radiation doses received by personnel 
working in the Transportation Cask Receipt and Return Facility (TCRRF) of the repository 
including the personnel at the security gate and cask staging areas. This calculation is required 
to support the preclosure safety analysis (PCSA) to ensure that the predicted doses are within the 
regulatory limits prescribed by the U.S. Nuclear Regulatory Commission (NRC). 
The Cask Receipt and Return Facility receives NRC licensed transportation casks loaded with 
spent nuclear fuel (SNF) and high-level radioactive waste (HLW). The TCRRF operation starts 
with the receipt, inspection, and survey of the casks at the security gate and the staging areas, and 
proceeds to the process facilities. The transportation casks arrive at the site via rail cars or trucks 
under the guidance of the national transportation system. 
This calculation was developed by the Environmental and Nuclear Engineering organization and 
is intended solely for the use of Design and Engineering in work regarding facility design. 
Environmental and Nuclear Engineering personnel should be consulted before using this 
calculation for purposes other than those stated herein or for use by individuals other than 
authorized personnel in the Environmental and Nuclear Engineering organization. 
2. QUALITY ASSURANCE 
This document was prepared in accordance with AP-3.12Q, Design Calculations and Analyses. 
Since the results of this calculation are used to support Preclosure Safety Analysis relative to 
radiological safety of the TCRRF workers, this document is subject to the requirements of 
Quality Assurance Requirements and Description (DOE 2004 [DIRS 1 7 1 5391, Section 2.2.2). 
3. METHOD 
The dose assessment involves calculations of annual individual and collective doses to TCRRF 
workers. These occupational doses are defined as the total effective dose equivalent (TEDE) 
received by workers involved in TCRRF operations. The TEDE consists of the deep dose 
equivalent (DDE) from direct exposure (contained sources and airborne radionuclides), summed 
with the committed effective dose equivalent (CEDE) from inhalation of airborne radionuclides. 
The calculated doses are based on expected worker occupancy factors and exposure times, area 
radiation dose rates, distances to radiation sources, and the number of personnel involved in each 
operation. 
The TCRRF provides space, layout, and structures that support waste handling operations. The 
waste handling operations at TCRRF receive transportation casks at the site entrance. The cask 
is unloaded from the transportation carrier and integrated with the onsite cask-handling system 
within the TCRRF protective structure to support the throughput rates established for waste 
emplacement. The TCRRF also requires interface with other repository systems that perform or 
support waste handling systems. Work groups comprising the TCRRF personnel are 
transportation personnel (TP), cask operator (CO), health physicist (HP), gantrylcrane operator 
(GO), and security personnel (SP). TP duties include the movement of a full or empty 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
casklcarrier into and out of the transfer bay. CO and GO function together and their duties 
involve removal of personnel barrierslimpact limiters, cask transfers from carrier to site rail 
transport car (SRTC), and inspection. HP monitors radiation and contamination levels during 
cask receipt and transfer. SP provides security functions at the receiving station. A detail of 
process steps given in Table 1 is based on Cogema BFD Level 2 [DIRS 1689641. 
The dose assessments are performed by job function or worker groups using the time-distance 
inputs and dose rates estimated at various worker locations (see Table 1). 
Table 1. Transportation Cask Receipt and Return Facility Process Steps 
TCRRF Process Step I (min) I Worker Distance (m)'l Dose ate^ (mremlhr) 
CASK Staging Activities 
0.0 
0.1 
0.2 
0.3 
0.4 
I 1 0.6 l ~ a d tech escort I I I 
Open exterior door 0 
Move carrierlcask into transfer bay with 15 511.72 101.54 101.54 101.54 
prime mover 
Disconnect and move prime mover 0 
outside 
8 
Receive, inspect, and drive cask to 
transfer bay 
I 
Verify transportation document 
Inspect vehiclelcask for any damage 
Security vigilance 
Radiological survey 
1 0.5 l ~ r i v e to transfer bay 
Prepare crane for personnel barrier 15 101.54 101.54 511.72 
removal 
15 1 215.36 1 
Remove and stage personnel barrier 30 1 118.90 1 101.54 1 511.72 1 I I I 
65 
5 
10 
10 
10 
I I I I 
I 
-TP:' 
215.36 
1 2.3 Iprepare crane for impact limiters removal 1 15 1 101.54 1 101.54 1 511.72 1 
Remove and stage impact limiters 
Inspect cask for damage (visual) 
February 2005 
.\CO I HP,! 
, 
118.90 
I I 
2.6 
2.7 
2.8 
40 
15 
G O 
118.90 
Perform contamination and radiation 
survey on accessible areas 
Replace and secure impact limiters 
Prepare empty SRTC and position 
nearby 
* ' SP 
118.90 
118.90 
118.90 
I 
10 
30 
0 
101.54 
101.54 
511.72 
101.54 
101.54 
118.90 
118.90 
101.54 
101.54 
511.72 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
Table 1. Transportation Cask Receipt and Return Facility Process Steps (Continued) 
1 Expected 1 Durationa 
3.1 Prepare crane, load cask lifting yoke on 0 
crane hook. 
3.2 Adjust universal lifting yoke to suit 5 118.90 101.54 511.72 
specific cask 
3.3 Mount lifting lugs on skid or trunnions on 15 118.90 101.54 511.72 
cask 
3.4 Engage lifting yoke with skid lifting lugs 5 101.54 101.54 511.72 
or cask trunnions -- -- 
3.5 Remove cask skid tie-downs 15 118.90 101.54 511.72 
I 1 3.6 l~ransfer casklskid from carrier to SRTC I 15 1 101.54 1 101.54 1 511.72 1 
3.7 Secure casklskid to SRTC 15 118.90 101.54 511.72 
3.8 Disengage cask lifting yoke 5 118.90 101.54 511.72 
3.9 Withdraw cask crane to staging area 0 
3.1 0 Retrieve personnel barrier and re-install 20 118.90 101.54 101.54 
on casklskid I - - - - - - - - I 
4.0 Transfer SRTCIcask from transfer bay to . 85 -I.!'> GO HP . GO -- SP 
$ ' bufferC h I + 
I I I 
4.1 Open transfer bay door(s) 0 
4.2 Retrieve carrier prime mover and SRTC 0 
tractor 
4.3 Connect prime mover and undock carrier 15 511.72 
and move out of transfer bay 
4.4 Close transfer bay external door 0 
4.5 Return empty carrier to rail or truck 15 
queuing yardlparking 
4.6 Retrieve SRTC tractor and connect to 15 511.72 
SRTC I 
4.7 Move SRTClcask to SRTC positioner 10 511.72 
4.8 Close transfer bay external door 0 
4.9 Move SRTC positionerlcask to align with 10 511.72 
desired staging location 
I 1 4.1 0 I ~etrieve SRTC tractor and move 1 10 1511.721 I I I ISRTCIC~S~ into desired staging location I 
I I I I I I I I I 1 4.1 1 l~isconnect tractor from SRTClcask I 0 I I I I I 
I 1 5.1 I ~etrieve SRTC tractor and connect to 1 15 1 511.72 1 I I I 
February 2005 
5.2 Move SRTCIcask from staging location 
onto SRTC positioner 
10 511.72 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
Table 1. ~rans~ortation Cask Receipt and Return Facility Process Steps (Continued) 
Distance (my1 Dose Rateb (mremlhr) 
NOTES: a Expected exposure time are based on anticipated values when compared to similar activities as reported 
in General Atomics 1993 [DIRS 1047761, Table 7.5-3. 
Dose rates are from Table 3, Column C 
'These steps are followed in reverse order to return empty cask to transfer bay. Return of empty cask is 
mainly performed in non-radiation area except in buffer area. Dose received in buffer area is assumed to 
be the same as if the cask is loaded for a conservative estimate. 
CHF: Canister Handling Facility 
4. DESIGN INPUTS 
This dose assessment calculates annual individual and collective doses received through process 
steps performed by the TCRRF workers. Design inputs include the list of process steps, 
exposure times, and source term dose rates as a function of distance to the worker. (Table 1) 
4.1 PROCESS STEPS TIME-DISTANCE INPUTS 
The five different work groups in the TCRRF perform duties that will require different exposure 
time at different distances from the transportation cask. Table 1 displays the process steps, and 
expected exposure times and distances of the TP, CO, HP, and GO worker types in the TCRRF 
and SP at the transporter receiving gate. Process steps are preliminary at this time, but it is 
intended that Table 1 is as detailed as possible about process steps in the TCRRF. Expected 
exposure distance and time for task completion in the TCRRF are based on anticipated values 
when compared to similar activities as reported in General Atomics 1993 [DIRS 1047761, Table 
7.5-3. 
4.2 EXTERNAL DOSE FROM TRANSPORTATION CASK 
4.2.1 Dose Rates as a Function of Distance for Universal Transport Cask 
Per Assumption 4.3.1, the dose rates received by TCRRF workers at various distances ffom a 
transportation cask are derived from the 2 m dose rates of the universal transport cask (NAC 
International 2002) and the radial dose distance factors are derived based on the methodology 
developed in BSC 2004 [DIRS 1717721, Attachment I. Per Table 1, workers are modeled to be 
at 1,2, 5, 10, and 15 m from the exterior surfaces of a loaded transportation cask. Dose rates at 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
these distances are estimated and described in Assumption 4.3.1. The average dose rates at the 
five distances are 8.9, 5.36, 1.72, 0.54, and 0.34 rnrem/hr, respectively. These dose rates are 
used in worker dose assessment of the TCRRF. 
Tables 2 and 3 summarize the TCRRF worker dose rates versus distance described in 
Assumption 4.3.1. 
Table 2. 2 rn Dose Rates (mrernlhr) of Universal Transport Cask 
I Radial [C] 9.6 10.00 (bounding) 
Dose Rate [A] 
- - 
Scaled Dose Rate [B] 
I I 
Top Axial [Dl 
Bottom Axial [El 
Source: Column [A]: From NAC International 2002 [DIRS 1646121, Table 5.1-1 
1 Weighted Average [F] 
Column [B] = Column [A] x 10.0 I 9.6. Scaled dose rate is discussed in Assumption 
4.3.1 
0.1 
1.3 
Row [F] = 0.5 x Row [C] + 0.25 x Row [Dl + 0.25 x Row [El (BSC 2004 
[DIRS 171 7721, Attachment I) 
0.10 
1.35 
5.15 
Table 3. Estimated Dose Rates for A Typical Rail Cask 
5.36 
4.2.2 External Dose from Contained Source 
Distance [A] 
I rn 
2rn 
5rn 
10 m 
15 rn 
20 rn 
The annual external dose from the contained source per individual worker is calculated as: 
where: 
Source: Column [A] from Col 1 of BSC 2004 [DIRS 171 7721, Table 1-5. 
Column [B] from Col 7 of BSC 2004 [DIRS 1717721, Table 1-5. 
Column [B] row 6 interpolated distance factor between 10 and 20m 
Column [C]: 5.36* Col [B] 
Dose Distance Factor [B] 
1.66 
1 .OO 
0.32 
.0998 
.0633 
.0669 
DRI,g= External dose rate at location i per individual worker per worker group g 
(rnrem/hr). 
Dose Rate (mremlhr) [C] 
8.90 
5.36 
1.72 
0.53 
0.34 
0.144 
Ti = Duration of the exposure at location i, per cask operation (hrlcask). 
TC = Number of processed transportation casks per year (caskslyr). 
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Trans~ortation Cask Recei~t and Return Facilitv Worker Dose Assessment 
WS = Number of work shifts. (Assumption 4.3.2) 
4.2.3 Inhalation Dose from Airborne Source 
The volumetric flow rate of recycled air in the TCRRF is used as an input to determine the 
airborne radionuclide concentration. It is calculated as: 
where: 
V = Volumetric flow rate of air (m3/s). 
L = Length of TCRRF floor plan (m) (see Assumption 4.3.13). 
W = Width of TCRRF floor plan (m) (see Assumption 4.3.13). 
H = Truncated height of TCRRF (m) (see Assumption 4.3.13). 
A = Air change rate (hr") (see Assumption 4.3.9). 
F = Fraction of outside makeup air (see Assumption 4.3.9). 
U = Unit conversion factor from hr to s. 
Airborne radionuclide concentration is calculated as: 
where: 
Ci = Airborne concentration of respirable radionuclide i (ci/m3). 
SC = Maximum allowable radionuclide surface contamination (ci/m2) 
(see Assumption 4.3.10, note: dpm/cm2 is converted to cum2 using 4.5~10"). 
SA = Surface area of 6 casks (m2) (see Assumption 4.3.12). 
RR = Resuspension rate (hr-') (see Assumption 4.3.7). 
U = Unit conversion factor from hr to s. 
The CEDE can be calculated from the airborne radionuclide concentration by [DIRS 160582, 
NRC 2003, section 4, page 91: 
where: 
CEDEI = Committed effective dose equivalent of radionuclide i (mrem). 
B-Rate = Worker breathing rate, 3.33E-4 m3/s (10 CFR Part 20, Appendix B, Footnote 
to Table 1). 
T = Duration of exposure for routine release in a year (hr) (see Assumption 4.3.5). 
DCFi = Inhalation dose conversion factor for radionuclide i (Sv/Bq). 
UI = Unit conversion factor from s to hr. 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
u2 = Unit conversion factor from Sv/Bq to mredCi using 3.7~10"~. 
4.2.4 DDE and TEDE 
DDE is calculated as: 
DDEi = Deep dose equivalent of radionuclide i. 
T = Duration of exposure for routine release in a year (hr) (see Assumption 4.3.5). 
ACFi = Submersion dose conversion factor for radionuclide i (SV-m3mq-s). 
U1 = Unit conversion factor from s to hr. 
U2 = Unit conversion from SV-m3/Bq-s to mrem-m3/ci-s (using definitions Bq=2.7E- 
1 1 Ci, and Sv=100remxlE+3mrem/rem= lE+05mrem) is 3.7~1 0+15. 
Individual annual TEDE is calculated as [DIRS 160582, NRC 2003, section 4, page 101: 
where: 
TEDEi, = Individual work group member total effective dose equivalent for radionuclide 
i (mrem) (see Assumption 4.3.3). 
CEDEi = Committed effective dose equivalent for radionuclide i (mrem). 
DDEi = Deep dose equivalent for radionuclide i (mrem). 
Collective annual TEDE is calculated as: 
where: 
TEDEi,, = Collective total effective dose equivalent for radionuclide i (person-mrem). 
WG, = Total number of individual workers per work group g (see Assumption 4.3.3). 
4.3 ASSUMPTIONS 
4.3.1 Dose Rate and the Cask Model 
The dose rates in the immediate vicinity of the universal transport cask (Table 2) are used to 
estimate dose rates received by workers while processing a transportation cask in the TCRRF. It 
is assumed that the 2 m dose rates of the universal transport cask and the radial dose distance 
factor computed for the TN-32 cask (BSC 2004 [DIRS 1717721, Table 1-5) can be used to 
estimate dose rates received by workers at various distances fi-om the exterior surfaces of a 
transportation cask. The 2 m dose rates from the radial, top, and bottom surfaces of the universal 
transport cask are 9.6, 0.1, and 1.3 mrem/hr, respectively (Table 2). These dose rates are scaled 
up to 10.0, 0.1, and 1.35 mrem/hr so that the 10 mrem/hr at 2 m from the surface represents the 
bounding case for cask external radiation level limits specified by 10 CFR 71.47. 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
It is also assumed that the dose rate received by TCRRF workers at 2 m is the weighted average 
value of the bounding radial, top, and bottom dose rates, or (50%) (10.0) + (25%) (0.1) + (25%) 
(1.35) = 5.36 rnremthr (See Table 2). The dose rates for TCRRF workers at 1,5, 10 and 15m are 
then estimated using this 2 m dose rate and the radial dose distance factors derived fiom the TN- 
32 cask in Table 1-5 of BSC 2004 [DIRS 171 7721. 
Rationale: The universal transport cask is designed to meet 10 CFR Part 71 licensing 
requirements for radioactive material transport packages (NAC International 2002 [DIRS 
1646121, Section 1.1 and Section 4.4.2. The radial dose distance factor computed for the TN-32 
cask (BSC 2004 [DIRS 1717721, Table 1-5) is representative of rail transportation casks such as 
the universal transport cask because they have similar exterior dimensions. 
Usage: This assumption is summarized in Tables 2 and 3. 
4.3.2 Number of Work Shifts in the T C W 
A minimum of five work shifts is assumed for the TCRRF personnel. 
Rationale: This minimum is deemed reasonable for a 24 hour, 7 days a week continuous 
TCRRF operations. 
Usage: This assumption is used in Equation 1 and sections 6.1 and 6.2.1. 
4.3.3 Number of Crew Members for the TCRRF 
One TCRRF crew is assumed to consist of 1 TP, 3 COs, 1 HP, 1 GO, and 2 SPs. 
Rationale: This assumption was based in part on the number of workers and tasks described in 
the GA-4 Cask Safety Analysis Report for Packaging (General Atomics 1998 [DIRS 1030421, 
Section 7) as well as the anticipated personnel needed to conduct the process step tasks detailed 
in Table 1. 
Usage: This assumption is used in worker dose calculations in Attachment I using Equation 7 
and Section 6.2.1. 
4.3.4 Approximate Worker Distances from the Transportation Cask 
The various worker locations throughout the TCRRF in terms of distances from the 
transportation cask (Table 1) are estimated fiom the approximate lengths of the reach tools used 
as well as the likely worker locations to perform the cask preparation operations in the TCRRF. 
Rationale: This assumption reflects the approximate worker locations for the required cask 
preparation operations in the TCRRF. 
Usage: This assumption as shown in Table 1 is used in the worker dose calculations in 
Attachment I using Equation 1. 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
4.3.5 Annual Number of Work Hours in the TCRRF 
The TCRRF worker is assumed to spend 2000 hrslyr inside the TCRRF for dose contributions 
from an airborne source. 
Rationale: This value for the airborne source bounds the number of hours a typical worker will 
spend inside the TCRRF during the year working a regular schedule. 
Usage: This assumption is used in worker dose calculations in Attachment I using Equations 4 
and 5 and Section 6.2. 
4.3.6 Exposure Times in the TCRRF 
The times under which the TCRRF workers are exposed to radiation while working in the 
TCRRF are as shown in Table 1. 
Rationale: This assumption is based on the times provided for each task associated with cask 
operations in the GA-9 cask final design report, and with the extensive experience of General 
Atomics in actual use of truck casks for shipments of gas-cooled reactor spent fuel and BWR 
control blades (General Atomics 1993 [DIRS 1047761, Table 7.5-3). Time estimates were also 
based on anticipated times to complete tasks performed by TCRRF personnel. 
Usage: This assumption was used in worker dose calculations in Attachment I using Equation 1. 
4.3.7 Cask Surface Contamination Resuspension Rate 
It is assumed that the resuspension rate from the transportation cask surface contamination is 
4 x 1 o - ~ Ihr. 
Rationale: This resuspension factor is the bounding value recommended for aerodynamic 
entrainment of powders from unyielding surfaces for indoors and outdoors exposed to ambient 
conditions following an event (DOE 1994 [DIRS 1037561, Section 5, p. 5-7). 
Usage: This assumption is used in worker dose calculations in Equation 3 and Section 6.2. 
4.3.8 Inhalation of Airborne Radionuclides 
It is assumed in the dose calculations that all released or suspended radioactive particles are 
respirable. 
Rationale: This assumption is appropriate because it yields the most conservative dose values. 
Usage: This assumption is used in worker dose calculations in Attachment I using Equation 3. 
4.3.9 Air Exchange Rate and Composition in the TCRRF 
The air change rate in the TCRFW area during normal operations is assumed to be four air 
changes per hour and ten percent of the air exchange is outside air makeup. 
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Trans~ortation Cask Recei~t and Return Facilitv Worker Dose Assessment 
Rationale: The ventilation rate for the TCRRF is based on a minimum of four air changes per 
hour (BSC 2004 [DIRS 1715991, Section 4.8.2.3.5). A minimum of ten percent of the air 
exchange is outside air makeup (BSC 2004 [DIRS 1715991, Section 4.8.2.3.4). 
Usage: This assumption is used in worker dose calculations (Attachment I) using Equation 2 
and Section 6.2. 
4.3.10 Identity of Airborne Radionuclides and the Cask Surface Area Contamination 
Limits 
The most significant radioactive isotope released is assumed to be Cobalt-60 (Co-60), and the 
surface contamination of the Co-60 on the transportation casks is assumed to be 220 dpmlcm2. 
Rationale: Co-60 is assumed because any contamination on the exterior surface of the 
transportation cask is likely to come fiom the radioactive particulates suspended in the spent fuel 
pool water at the originating nuclear power plant. At the time of loading, most of the particulates 
in the pool are the long half-life corrosion products fiom SNF surfaces that might dislodge 
during SNF movement. The most prominent particulates are Co-60, Co-58, Iron-55, Iron-59, 
Manganese-54, Chromium-51, and Zinc-65 (NRC 2001 [DIRS 1577611, Section 4.7.2.3, 
p. 4-51). Of these products, Co-60 has the lowest derived air concentration of 1.OE-8 ci/m3 for 
class Y radioactive material (10 CFR Part 20, Column 3 of Table 1 of Appendix B) and the 
longest half-life of 5.27 years (Kocher 1981 [DIRS 1056221, p. 78). Also, all other particulate 
sources including fission products (e.g., Sr-90 and Cs-137) and actinides (alpha emitters) are at a 
minimum or insignificant, relative to Co-60 in terms of potential contamination levels. 
The contamination limits for exclusive-use shipments by rail or highway (i.e., vehicles dedicated 
solely to the transport of radioactive packages and are appropriately marked on the exterior "For 
Radioactive Materials Use Only"), may not exceed 10 times the limits for non-exclusive use 
shipments contained in Table 11, of 49 CFR 173.443 (Section 4.4.3), Contamination Control. 
The use of the maximum allowable removable surface contamination value during exclusive-use 
transport is appropriate because it is a bounding condition and will yield conservative dose 
values. 
Usage: These assumptions are used in worker dose calculation in Equation 3 and Section 6.2. 
4.3.11 Extent and Mobility of the Cask Surface Contamination 
Surface contamination is assumed to cover the entire external surface of the transportation cask, 
and all of the contamination is assumed to be removable and releasable to the atmosphere. 
Rationale: The amount of surface contamination assumed to be available for release to the 
atmosphere using the resuspension rate discussed in Assumption 4.3.7 is significantly higher 
than is anticipated for transportation casks to be handled at the TCRRF. This is because only a 
small portion, if any, of the cask's exterior would have any removable contamination due to the 
preventive measures used during underwater loading at the originating nuclear power plant. The 
originating nuclear power plant would decontaminate the exterior of the cask to the acceptable 
level prior to shipment. Surveying of the cask's exterior for contamination will also be 
performed upon the receipt of the cask at the TCRRF. Therefore, the amount of removable 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
contamination available hypothetically to become airborne under normal conditions in the 
TCRRF would be significantly less than the amount assumed. 
Usage: This assumption is used in worker dose calculations using Equation 3 and in section 6.2. 
4.3.12 Maximum Airborne Radioactivity in TCRRF 
Airborne radioactivity dose calculation is based on contamination on all six casks inside TCRRF. 
It assumed that all casks have surface contamination to the maximum allowable limit. The 
surface area of the cask is estimated to be 289 m2 (see Attachment I), which is representative of a 
universal multipurpose canister system cask of length 5.3 m and radius 1.18 m (NAC 
International 2002, Table 1.2-1). 
Rationale: This assumption is consistent with the design capacity of the TCRRF and 
incorporates conservatism to doses from the airborne source. 
Usage: This assumption is used in worker dose calculations using Equation 3. 
4.3.13 Affected Volume of the TCRRF 
A height of 20 ft (6.096 m), truncated from 43 ft, 9 in., length of 225 ft (68.580 m) (BSC 2004 
[172144]) and width of 131 ft (39.929 m) (BSC 2004 [168452]) are used in the calculation of the 
affected volume (m3) of the TCRRF. 
Rationale: This height reduction increases the Co-60 airborne concentration in the worker area; 
hence, yielding conservative doses from airborne radioactivity. 
Usage: This assumption is used in worker dose calculation in Equation 2. 
4.3.14 Annual Number of Casks Handled in the TCRRF 
The total number of transportation casks that will be shipped to the repository annually is 
assumed to be 507 (BSC 2003 [DIRS 1659901, Table 16). 
Rationale: This annual cask arrival represents a realistic and reasonable number of commercial 
transportation casks that the TCRRF will have to process. 
Usage: This assumption is used in Section 6 and Attachment I. 
4.3.15 Average Dose Rate Reduction Factor 
The average external dose rate from SNF cask received is one-fifth of the design-basis dose. 
Rationale: All transportation casks are required to meet the external radiation level limits 
specified by 10 CFR 71.47 (Section 4.4.2). The design basis PWR SNF characteristics at the 
repository are 4 percent initial enrichment, 60 GWdMTU burnup and 10 year cooling, (BSC 
2002 [161120], section 5.5.2) the average SNF characteristics are 4 percent enrichment, 48 
GWd/MTHM burnup, and cooled for 25 years (BSC 2004 [169061], Attachment IX). Dose rates 
based on the average SNF at the repository are more representative and appropriate for worker 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
dose assessment. Based on dose ratios derived in Dry Transfer Facility Worker Dose 
Assessment (BSC 2004 [171772], Table I-5), the dose rate reduction factor from design-basis 
SNF to the average SNF received at the repository is about 5. 
Usage: This assumption is used in Attachment I for dose calculations. 
4.4 REGULATIONS 
4.4.1 10 CFR 20.1201 
The regulation applicable to worker doses is contained in 10 CFR 20.1201, Occupational Dose 
Limits for Adults: 
(a) The licensee shall control the occupational dose to individual adults to the an 
annual limit of the TEDE being equal to 5 rems. 
4.4.2 10 CFR Part 71.47 
0.1 mSv/h (10 mremlh) at any point 2 meters (80 in.) from the outer lateral surfaces of the 
vehicle (excluding the top and underside of the vehicle); or in the case of a flat-bed style vehicle, 
at any point 2 m (6.6 feet) from the vertical planes projected by the outer edges of the vehicle 
(excluding the top and underside of the vehicle); 
4.4.3 49 CFR 173.443 
Non-fixed (removable) contamination limits: 
a) Less than or equal to 220 dpm/ cm2 averaged over 300 cm2 j3-y 
b) Less than or equal to 22 dpml cm2 averaged over 300 cm2 a 
4.5 CRITERIA 
ALARA design goals (BSC 2004 [DIRS 1715991, Section 4.9.3.3) for occupational workers 
ensure that both individual and collective annual doses are maintained at ALARA levels during 
normal operations and as a result of Category 1 event sequences. The following ALARA design 
goals are established for the design process. 
"The ALARA design goal for individual radiation worker doses is to minimize 
the number of individuals that have the potential of receiving more than 
500 mremlyr total effective dose equivalent (TEDE). That goal is 10% of the 
annual TEDE limit in 10 CFR 20.1201, and includes both internal and external 
exposures." 
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Transportation Cask Receipt and Return Facility Worker Dose Assessment 
5. USE OF SOFTWARE 
Microsoft Excel 97 (spreadsheet program) is used to perform simple calculations. User-defined 
formulas, input, and results are documented in sufficient detail in Section 6 and Attachment I to 
allow for independent duplication of the various computations without recourse to the originator. 
This software is exempt from the requirements of LP-SI. 1 1Q-BSC, Software Management. 
6. CALCULATIONS 
6.1 WORKER DOSE FROM CONTAINED SOURCE 
Using the equations and assumptions of Section 4, external dose is calculated by worker group in 
Attachment I. The five worker groups (TP, CO, HP, GO, and SP) in the TCRRF perform job 
functions requiring different time intervals and distances from the shipping casks. Table 4 
summarizes external dose per cask processed and annual dose for each member of a worker 
group. Total expected time duration per cask for the governing process step is the summation of 
its subprocess step times (Table 1). Total dose per cask are based on distance for each 
subprocess step (Table 1) and are read from Table 3 then summed together for each governing 
process step. Equation 1 is used to determine the annual dose from the contained source. 
Table 4. Summary of TCRRF Worker Dose Due To Direct Exposure by Group 
6.2 WORKER DOSE FROM AIRBORNE SOURCE 
Worker Group (1) 
Transportation Personnel (TP) 
Cask Operator (CO) 
Health Physicist Technician (HP) 
Gantry Operator (GO) 
Security personnel (SP) 
Table 5 is a listing of numerical values and their sources calculated or used in Attachment I using 
the equations of Sections 4.2.3 and 4.2.4 to calculate CEDE and airborne source contribution to 
the DDE. 
February 2005 
NOTES: (1) TCRRF Worker Group from section 3. 
(2): Calculated in Attachment I using Excel spread sheet program based on 10 mremlhr dose 
rate limit at 2 m radial distance (Table 2) 
(3) = (2) x 507 (Assumption 4.3.14) 15 (Assumption 4.3.2) 
Bounding External 
Dose per Cask 
(mremlcas k) (2) 
2.6 
6.1 
1.1 
1.3 
0.3 
Annual Average External 
Individual Dose 
(mremlyr) (3) 
260 
620 
110 
130 
30 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
Table 5. Numerical Values used for Airborne CEDE and DDE Calculation 
Parameter 
Airborne concentration of Co-60 
Inhalation Co-60 dose conversion 
factor 
Air immersion Co-60 dose 
conversion factor 
Maximum allowable Co-60 surface 
contamination 
Surface area of 6 casks 
Resusupension rate 
Volume of TCRRF 
Fraction of outside air makeup 
Air exchange rate 
Volumetric flow rate 
Worker breathing rate 
Final Units 
ci/m3 
mremlCi 
Value 
5.95E-13 
1.10E+08 
5.37E+02 
9.91 E-07 
289 
4.00E-05 
16693 
0.1 
4 
1.85 
3.33E-04 
Duration of exposure (hrs) 
Source 
Calculated with Eq. 3 
ICRP 1995 [DIRS 172721],Tables B.1,C.l. 
2000 
Eckerrnan 1993 [DIRS 1076841, Table 111-1 
Assumption 4.3.10 
Attachment I 
Assumption 4.3.7 
Assumption 4.3.13 
Assumption 4.3.9 
Assumption 4.3.9 
Calculated with Eq. 2 
(20,000 mllmin): 10 CFR Part 20. Appendix 
B 
6.2.1 Worker TEDE 
Annual TEDE per individual worker determined from Equation 6 is 260, 620, 110, 130, and 
30 rnrem for TP, CO, HP, GO, and SP, respectively. TEDE from airborne source is insignificant 
when compared to dose received from direct exposure from contained sources and therefore is 
deemed negligible. All calculations of external dose, CEDE, and DDE using the equations of 
Section 4 are detailed in Attachment I. 
Collective annual TEDE from Equation 7 is 1.3, 9.2, 0.55, 0.66, and 0.3 person-rem for TP, CO, 
HP, GO, and SP, respectively. The sum of these collective annual TEDEs is 12 person-rem. 
Table 6 summarizes the above dose calculations. 
February 2005 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
Table 6. Average Dose for the TCRRF Workers 
NOTES: aCalculated in Attachment I. 
(4) = (2) + (3) 
(5): Assumption 4.3.3 
(6): Assumption 4.3.2 
(7): (4) x (5) x (6) / 1000 (remlmrem). 
Worker 
(1 ) 
TP 
CO 
HP 
GO 
SP 
Total 
7. RESULTS 
Individual and collective doses to the TCRRF worker are estimated using the methodology 
described in Section 3, process steps listed in Section 4.1, equations described in Section 4.2, 
assumptions defined in Section 4.3, the software described in Section 5, and the calculations 
performed in Section 6 and Attachment I. Appropriate and conservative input data and 
assumptions support the parameters used in the dose calculations. The outputs are reasonable 
compared to the inputs and the results are suitable for the intended use 
Cask 
External TEDE 
(mremlyr) 
(2)= 
2.6E+02 
6.2E+02 
1 .I E+02 
1.3E+02 
3.OE+01 
-- 
Annual average TEDE per individual worker is 270, 620, 110, 130, and 30 mrem for TP, COY 
HP, GO, and SP respectively (Table 6, Column 4). Higher CO doses for process in TCRRF are 
attributed to their process steps, which have the closest distance proximity to the transportation 
cask when compared to the other worker groups (Table 1). An ALARA design and operations 
review would recommend ways to reduce the dose to all worker types. Certain other activities at 
the facility, such as returning the empty transporter to parking areas will expose TP to low levels 
of radiation in the area. These doses, however, would be small compared to the direct exposure 
from handling loaded casks due to the fact that shipping casks do not contain radioactive 
components and no maintenance is anticipated. TCRRF worker dose assessed in this report is 
conservative since it based on rail shipment that results in higher doses compared to that based 
on truck shipment. The maximum overall shipment of 507 used in this calculation includes 
about 113 truck shipment, and no credit is taken to the reduced dose rate corresponding to truck 
casks. Annual TEDE (0.91 mrem) from exposure to airborne source is insignificant when 
compared to doses received from direct exposure to contained sources and therefore is deemed 
negligible. 
7.1 COMPARISON WITH REGULATORY LIMITS 
Airborne 
Exposure TEDE 
(mremlyr) 
(3)= 
4.6E-01 
4.6E-01 
4.6E-01 
4.6E-01 
-- 
-- 
All annual individual doses, predominantly due to direct exposure, calculated in Section 6 are a 
factor of 8 or more times lower than NRC regulatory limit of 5 rem/yr TEDE (Section 4.4.1). 
140-00C-CC00-00200-000-00B 23 February 2005 
Total TEDE 
(mremlyr) 
(4) 
2.7E+02 
6.2E+02 
1.1 E+02 
1.3E+02 
3.OE+01 
-- 
Number of 
Workers 
per Shift 
(5) 
1 
3 
1 
1 
2 
-- 
Number of 
Crews 
(6) 
5 
5 
5 
5 
5 
Collective TEDE 
(person-rem)lyr 
(7) 
1.3E+00 
9.2E+00 
5.5E-01 
6.6E-01 
3.OE-01 
1.2E+01 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
7.2 COMPARISON WITH ALARA GOAL 
All annual individual doses calculated in Section 6 are lower for all the work groups except that 
it is slightly higher for COs than ALARA design goal of 500 mrernlyr TEDE (Section 4.5). 
8. REFERENCES 
8.1 DOCUMENTS CITED 
BSC (Bechtel SAIC Company).2002. Subsurface Shielding Source Term 
Speczjkation Calculation. 000-00C-WERO-00100-000-00A. Las Vegas, Nevada: 
Bechtel SAIC Company. ACC: MOL.2002 12 16.0076.0001 
BSC (Bechtel SAIC Company) 2003. 2002 Waste Stream Projections Report. TDRCRW-
SE-000022 REV 01. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: DOC.2003 1020.0002. 
BSC (Bechtel SAIC Company).2004. Dry Transfer Facility Worker Dose Assessment. 
1 10-00C-CD00-00 100-000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040923.0001 
BSC (Bechtel SAIC Company) 2004. Transp Cask ReceiptIReturn Non-Nuclear 
Receipt facilities General Arrangement Equipment Platforms Plan B. 140-P10-Whs0- 
00107-000-OOA, Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20040413.0038. 
BSC (Bechtel SAIC Company) 2004. Transp Cask ReceiptIRetum Non-Nuclear 
Receipt facilities General Arrangement Sections H, J, K.. 140-P10-WHSO-00113- 
000-OOA, Las Vegas, Nevada: Bechtel SAIC Company. ACC: ENG.20041006.0009. 
BSC 2004. PWR Source Term Generation and Evaluation. 000-00C-MGRO-00100- 
000-00B. Las Vegas, Nevada: Bechtel SAIC Company. ACC: ENG.20040524.0007. 
DOE (U.S. Department of Energy) 1994. Analysis of Experimental Data. Volume 1 
of Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor 
Nuclear Facilities. DOE-HDBK-3010-94. Washington, D.C.: U.S. Department of 
Energy. TIC: 233366. 
DOE (U.S. Department of Energy) 2004. Quality Assurance Requirements and 
Description. DOEIRW-0333P, Rev. 16. Washington, D.C.: U.S. Department of 
Energy, Office of Civilian Radioactive Waste Management. 
ACC: DOC.20040907.0002. 
BSC(Bechte1 SAIC Company. 2004). Project Design Criteria Document. 000-3DRMGRO-
00100-000-003. Las Vegas, Nevada: Bechtel SAIC Company. ACC: 
ENG.20041124.0001. 
140-00C-CC00-00200-000-00B 24 February 2005 

Transportation Cask Receipt and Return Facilitv Worker Dose Assessment 
Cogema. 2004. Cask Receipt and Return System Block Flow Diagram Level 2 YMPC0115-
0502, Rev. H. Las Vegas, Nevada: Cogema. ACC:ENG.20041214.0003 
Eckerrnan, K.F. and Ryman, J.C. 1993. External Exposure to Radionuclides in Air, 
Water, and Soil, Exposure-to-Dose CoefJicients for General Application, Based on 
the 1987 Federal Radiation Protection Guidance. EPA 402-R-93-08 1. Federal 
Guidance Report No. 12. Washington, D.C. : U.S. Environmental Protection Agency, 
Office of Radiation and Indoor Air. TIC: 225472. 
General Atomics. 1993. GA-9 Legal Weight Truck From-Reactor Spent Fuel Shipping 
Cask, Final Design Report. 91035410. San Diego, California: General Atomics. 
ACC: NNA. 199405 13.0214. 
General Atomics. 1998. GA-4 Legal Weight Truck Spent Fuel Shipping Cask, Safety 
Analysis Report for Packaging (SAW). 910469/H. Two volumes. San Diego, 
California: General Atomics. TIC: 245137. 
ICRP (International Commission on Radiological Protection) 1995. Dose CoefJicients 
for Intakes of Radionuclides by Workers, Replacement of ICRP Publication 61. 
Volume 24, No. 4 of Annals of the ICRP. ICRP Publication 68. Tarrytown, New 
York: Pergamon. TIC: 235867. 
Kocher, D.C. 198 1. Radioactive Decay Data Tables, A Handbook of Decay Data for 
Application to Radiation Dosimetry and Radiological Assessments. DOEITIC- 1 1026. 
Washington, D.C.: U.S. Department of Energy. TIC: 228074. 
NAC International. 2002. Safety Analysis Report for the UMS@ Universal Transport 
Cask. UMST-02E. EA790-SAR-001. Docket No. 71-9270. Volume 1. Norcross, 
Georgia: NAC International. TIC: 254855. 
NRC (U.S. Nuclear Regulatory Commission) 2001. Final Environmental Impact 
Statement for the Construction and Operation of an Independent Spent Fuel Storage 
Installation on the Reservation of the Skull Valley Band of Goshute Indians and the 
Related Transportation Facility in Tooele County, Utah. NUREG- 17 14. Two 
volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission, Office of Nuclear 
Material Safety and Safeguards. TIC: 253836. 
NRC (U.S. Nuclear Regulatory Commission) 2003. "Interim Staff Guidance - 5, 
Revision 1. Confinement Evaluation." ISG-5, Rev 1. Washington, D.C.: U.S. Nuclear 
Regulatory Commission. Accessed January 24,2003. ACC: MOL.20030124.0247. 
http:l/www.ncr.gov/reading-ddoc-collectionslisg/spent-~el.html 
8.2 CODES, STANDARDS, REGULATIONS AND PROCEDURES 
104787 10 CFR 20. Energy: Standards for Protection Against Radiation. Readily available. 
1 6 1 8 1 7 10 CFR 20.120 1. Energy: Standards for Protection Against Radiation, Occupational 
Dose Limits for Adults. Readily available. 
140-00C-CC00-00200-000-00B 25 February 2005 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
167540 10 CFR 71.47.2001. Energy: External Radiation Standards for all Packages. Readily 
available. 
165690 49 CFR 173.443. Transportation: Contamination Control. Readily available. 
168413 AP-3.12Q, Rev. 2, ICN 2. Design Calculations and Analyses. Washington, D.C.: U.S. 
Department of Energy, Office of Civilian Radioactive Waste Management. ACC: 
DOC.200403 18.0002. 
171923 LP-SI.l 1Q-BSC, Rev. 0, ICN 1. Software Management. Washington, D.C.: U.S. 
Department of Energy, Office of Civilian Radioactive Waste Management. ACC: 
DOC.20041005.0008. 
February 2005 

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INTENTIONALLY LEFT BLANK 
February 2005 

Transportation Cask Receipt and Return Facility Worker Dose Assessment 
February 2005 

Transportation Cask Receipt and Return Facilitv Worker Dose Assessment 
ATTACHMENT I 
LISTING OF ELECTRONIC FILE IN CD CONTAINING WORKER 
DOSE CALCULATIONS 
The electronic file (Microsoft Excel workbook) of TCRRF worker dose calculations is provided 
on a compact disk as Attachment I. The worksheet file name and properties on the compact disk 
are listed in Table 1-1. 
Table 1-1. Worksheet Name and Properties in the Attachment I Compact Disk 
The above listed file has been saved on a CD-ROM disk that is included as an attachment to this 
document. 
Worksheet Name 
TCRRF ATT-Rev-B 2-15-05.xls 
February 2005 
Description 
TCRRF Worker Dose 
Assessment 
File Size (Bytes) 
79872 
Date 
February 15,2005 
Time 
8:11 AM