ML25037A006
| ML25037A006 | |
| Person / Time | |
|---|---|
| Site: | Kemmerer File:TerraPower icon.png |
| Issue date: | 02/06/2025 |
| From: | George Wilson TerraPower |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| TP-LIC-LET-0393 | |
| Download: ML25037A006 (1) | |
Text
15800 Northup Way, Bellevue, WA 98008 www.TerraPower.com P. +1 (425) 324-2888 F. +1 (425) 324-2889 February 06, 2025 TP-LIC-LET-0393 Docket Number 50-613 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk
Subject:
Transmittal of Responses to NRC's Request for Supplemental Information for Kemmerer Unit 1 Environmental Report TerraPower, LLC (TerraPower) on behalf of US SFR Owner, LLC (USO), a wholly owned subsidiary of TerraPower, submits this letter to provide responses to NRC's Request for Supplemental Information for Kemmerer Unit 1 Environmental Report. Enclosure 1 contains the non-proprietary responses to Environmental Audit questions ACC-1, ACC-2, FCRW-2, TR-1, and TR-4. The proprietary responses and the affidavit associated with withholding are contained in attachment 5 of TP-LIC-LET-0362 (ML24344A003).
This letter and enclosure make no new or revised regulatory commitments.
If you have any questions regarding this submittal, please contact Nick Kellenberger at nkellenberger@terrapower.com.
I declare under penalty of perjury that the foregoing is true and accurate.
Executed on February 06, 2025.
Sincerely, George Wilson Senior Vice President of Regulatory Affairs TerraPower, LLC
Enclosures:
- 1.
Responses to Supplemental Information ACC-1, ACC-2, FCRW-2, TR-1, cc:
Mallecia Sutton, NRC Josh Borromeo, NRC Patricia Vokoun, NMSS Daniel Barnhurst, NMSS Nathan Howard, DOE Jeff Ciocco, DOE and TR-4 (Non-Proprietary)
February 06, 2025 Page 2 of 2
TP-LIC-LET-0393 Page 1 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved Responses to Supplemental Information ACC-1, ACC-2, FCRW-2, TR-1, and TR-4 (Non-Proprietary)
ENCLOSURE 1
CORINV parameter (Indicated as being located in the ATMOS1.inp "les for RC-B-CB_19, RC-B-CB_20, RC-B-CB_21, and RCLB-1F_19) were provided as part of attachment 5 in the proprietary submittal (ML24344A003).
TP-LIC-LET-0393 Page 2 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved Recommended values from NUREG/CR-7270 are used, as appropriate. Tables 5, 6, and 7 show the MACCS input parameters and their bases for the ATMOS, EARLY, and CHRONC modules, respectively. The MACCS input and output "les are included in Appendix B of the calculation.
Source term information for RC-B-CB and RCLB-1F input into MACCS as related to the accidents, was provided as part of attachment 5 in the proprietary submittal (ML24344A003).
Natrium Document NAT-5119 which is the calculation for the environmental impacts of severe NUREG/CR-7270 NUREG/CR-7009 SAND2021-6924 for inputs that are speci"c to reactor design or site.
MACCS input and data uses the recommended values from the following documents except event sequences that have a mean frequency less than 5E-07/plant-year.
terms identi"ed in Table 5.11-20 are categorized as other quanti"ed events (OQEs). OQEs are sequences outside the bounds of LMP. The event sequences associated with the two source identi"able sources in the PSAR because the severe accident analysis considers event described in Chapter 3 of the PSAR. The information in Table 5.11-20 cannot be traced to The generation of severe accident analysis information follows the same methodology as TerraPower's Response:
with NUREG/CR-7270 and based on local environmental factors.
the staff needs to con"rm the use of recommended MACCS input data value in accordance provided in Table 5.11-20 cannot be traced to identi"able sources in the PSAR. Additionally, provided in Section 5.11.2, Table 5.11-20, and related material of the ER. The information Provide an SME to discuss the generation of the accident analysis information, such as that NRC Question:
NRC Question Number: ACC-1
TP-LIC-LET-0393 Page 3 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved The calculation used to estimate the maximum SAMA bene"t that can be achieved by eliminating the consequences of severe accidents was provided in attachment 5 of the proprietary submittal (ML24344A003).
TerraPower's Response:
for acceptability at the CP stage. Please note that as directed by the 1980 Commission Policy Statement on NPP accident considerations under NEPA (45 FR 40101), the ER submitted by applicants for construction permits on or after July 1, 1980 should include a discussion of the environmental risks associated with accidents.
application is based on preliminary design information that the safety review team is assessing analysis and SAMDAs. The staff needs to discuss this due to the PRA applied in the CP Provide an SME to discuss how LMP (e.g., NEI 18-04) was factored into the severe accident NRC Question:
NRC Question Number: ACC-2
TP-LIC-LET-0393 Page 4 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved Information Witheld Under 10 CFR 2.390 Information Witheld Under 10 CFR 2.390 (4)megawatt days/ MTU for Type 1 fuel, increasing to (( )) (a)(4) megawatt-days/MTU for Type 1B fuel. With higher burnup, the mass of spent fuel generated at Kemmerer 1 will be less than that considered in NUREG-2157, making the evaluation in NUREG-2157 bounding for Natrium. Full 1B transition will only be used as authorized through the License Amendment Request process after issuance of the Operational License. Transition to Fuel Type 1B is not anticipated until (( )) (a)(4).
MTU), whereas the average burnup for Natrium fuel is anticipated to be (( )) (a) assessment in NUREG-2157 is based on low-burnup fuel (less than 45,000 megawatt days/
signi"cantly different from those for LWR fuels evaluated in NUREG-2157. Also, the impact handling, storage, and management of spent fuel analyzed will apply to Kemmerer Unit 1. This is because the degradation rates of the storage systems for the Natrium fuel will not be Although advanced nuclear reactors were not directly included in the evaluation documented in NUREG-2157, it is reasonable to assume that the conclusions made regarding the safe TerraPower's Response:
commercial use in the United States at the time of publication.
reactors is not within the scope of the analysis in NUREG-2157 because that technology was in analysis of spent fuel storage impacts, however spent fuel generated by liquid metal fast a water-based environment). The ER Section 6.1.2.6.2 relies on NUREG-2157 as a bounding Please provide an SME to discuss the onsite storage of radiological wastes and spent fuel (e.g.,
NRC Question:
NRC Question Number: FCRW-2
TP-LIC-LET-0393 Page 5 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved Information Witheld Under 10 CFR 2.390 Information Witheld Under 10 CFR 2.390 the condition is not met.
metric ton uranium for Type 1 fuel and ((
)) (a)(4) megawatt-days per metric ton uranium for Type 1B fuel, which exceeds the 33,000 megawatt-days per metric ton of uranium limit; thus, Average burnup in the Natrium fuel is anticipated to be ((
)) (a)(4) megawatt-days per TerraPower's Response:
commitment to 90 days has been met, the ER does not specify the expected burnup of spent fuel. Please provide an estimate of the potential.
assembly is shipped until at least 90 days after it is discharged from the reactor. While the reactor does not exceed 33,000 megawatt-days per metric ton, and no irradiated fuel 10 CFR 51.52 (a)(3) states that The average level of irradiation of the irradiated fuel from the NRC Question:
NRC Question Number: TR-1
TP-LIC-LET-0393 Page 6 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved Kemmerer Unit 1 Environmental Report sections describing number of shipments of fuel and waste.
6.2.2 Number of Shipments and Normalization of Shipments.
The number of annual shipments at Kemmerer is normalized to the reference reactor and adjusted for the quantity limit per shipment:
The number of shipments is scaled to the reference reactor at 880 megawatts-electric.
Total number of shipments of unirradiated fuel is based on a 40-year plant life and is equal to the sum of the initial shipment and 39 annual reload shipments.
The number of shipments of irradiated fuel is based on a shipment cask capacity of 0.5 metric tons of uranium per shipment.
The number of shipments of radwaste is based on a shipment capacity of 2.34 cubic meters (82.6 cubic feet) per shipment.
Once the number of shipments in each category has been determined, it is scaled to the power level of the reference reactor to facilitate a direct comparison of the impacts with those presented in Table S-4. Dividing the reference reactor power of 880 megawatts-electric by the Natrium reactors minimum power of 319 megawatts-electric and its capacity factor of 92.5 percent yields a normalization factor of approximately 3.0.
6.2.2.1 Number of Shipments of Unirradiated Fuel Based on the initial core load and the subsequent reloads of Type 1 and Type 1B fuels, as shown in Table 6.2-1, the average annual shipment of unirradiated fuel over 40 years is approximately 27 assemblies. Global Nuclear Fuels - Americas, LLC estimates that a shipping container will accommodate two assemblies per package and 10 packages per shipment. This equates to an annual average of 1.4 shipments, which scales to 4.1 shipments when normalized to the power level of the reference reactor.
6.2.2.2 Number of Shipments of Irradiated fuel The average annual shipment of irradiated fuel over 40 years is approximately 23 assemblies.
Applying the RG 4.2 limit of 0.5 metric tons of uranium per shipment yields an annual average of 4.0 shipments, which scales to 12 shipments when normalized to the power level of the reference reactor.
direct use in RADTRAN.
appendices of the PDF "le. These "les are also provided separately as text "les to facilitate the proprietary submittal (ML24344A003). The RADTRAN input "les are shown in the TerraPower's Response:
The calculation for the environmental impacts of transportation was provided in attachment 5 of applied in the transportation analysis of ER Section 6.2 and related calculations.
Provide a knowledgeable expert to discuss the number of shipments of fuel and waste NRC Question:
NRC Question Number: TR-4
TP-LIC-LET-0393 Page 7 of 7 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009054 Copyright © 2025 TerraPower, LLC. All Rights Reserved meters). Applying the RG 4.2 limit of 2.34 cubic meters (82.6 cubic feet) per shipment yields an annual average of approximately 25 shipments, which scales to approximately 75 shipments when normalized to the power level of the reference reactor.
The average annual shipment of radwaste over 40 years is 2,070 cubic feet (58.6 cubic 6.2.2.3 Number of Shipments of Radwaste