Letter Sequence Approval |
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EPID:L-2024-TOP-0005, Transmittal of Terrapower, LLC Topical Report, Reactor Seismic Isolation System Qualification Topical Report, Revision 0 (Open) |
Results
Other: ML24163A003, ML24297A138, ML24297A140, ML24313A101, ML25206A270, ML25206A271, ML25316A009, ML25318A769, ML25318B192, ML25321A277, ML25321A282
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MONTHYEARML24068A2122024-03-0808 March 2024
Transmittal of Terrapower, LLC Topical Report, Reactor Seismic Isolation System Qualification Topical Report, Revision 0
Project stage: Request
ML24095A1532024-04-0404 April 2024
NRR E-mail Capture - Acceptance Review Comanche Peak Request to Revise Technical Specifications to Adopt TSTF-591, Revise Risk Informed Completion Time (RICT) Program (EPID 2024-LLA-0023)
Project stage: Acceptance Review
ML24163A0032024-06-24024 June 2024
Terrapower - Audit Plan - Instrumentation and Control Architecture and Design Basis Topical Report
Project stage: Other
ML24297A1382024-10-22022 October 2024
Public - Terrapower, LLC - Audit Plan for Topical Report: Reactor Seismic Isolation System Qualification, Revision 0 (Cac/Epid No. 000431/L-2024-TOP-0005)
Project stage: Other
ML24297A1402024-10-24024 October 2024
Email - Terrapower, LLC - Audit Plan for Topical Report: Reactor Seismic Isolation System Qualification, Revision 0 (Cac/Epid No. 000431/L-2024-TOP-0005)
Project stage: Other
ML24313A1012024-11-13013 November 2024
SLRA Supplemental Environmental Audit Plan
Project stage: Other
ML25206A2712025-07-25025 July 2025
Email: Request for Withholding Proprietary Information from Public Disclosure - Terrapower, LLC, NAT-8922 Reactor Seismic Isolation System Qualification Topical Report, Revision 2
Project stage: Other
ML25206A2702025-07-25025 July 2025
NRC 897: Request for Withholding Proprietary Information from Public Disclosure - Terrapower, LLC, NAT-8922 Reactor Seismic Isolation System Qualification Topical Report, Revision 2
Project stage: Other
ML25202A0682025-09-0909 September 2025
Terrapower, LLC - Draft Safety Evaluation for NAT-8922 Reactor Seismic Isolation System Qualification Topical Report, Revision 2
Project stage: Draft Approval
ML25296A2272025-10-24024 October 2025
Letter - Terrapower, LLC - Final Safety Evaluation for NAT-8922 Reactor Seismic Isolation System Qualification Topical Report, Revision 2
Project stage: Approval
ML25296A2292025-10-24024 October 2025
Enclosure - Terrapower, LLC - Final Safety Evaluation for NAT-8922 Reactor Seismic Isolation System Qualification Topical Report, Revision 2
Project stage: Approval
ML25316A0092025-11-12012 November 2025
Submittal of Approved Terrapower, LLC, Reactor Seismic Isolation System Qualification Topical Report
Project stage: Other
ML25321A2772025-11-17017 November 2025
Email - Request for Withholding Proprietary Information from Public Disclosure - Terrapower, LLC NAT-8922-A, Reactor Seismic Isolation System Qualification, Revision 2
Project stage: Other
ML25321A2822025-11-17017 November 2025
NRC Form 897 - Request for Withholding Proprietary Information from Public Disclosure - Terrapower, LLC NAT-8922-A, Reactor Seismic Isolation System Qualification, Revision 2
Project stage: Other
ML25318A7692025-11-17017 November 2025
NRC 896 - a Topical Report Verification of Terrapower, LLC Reactor Seismic Isolation System Qualification, NAT-8922?A, Revision 2
Project stage: Other
ML25318B1922025-11-17017 November 2025
Email - a Topical Report Verification of Terrapower, LLC Reactor Seismic Isolation System Qualification, NAT-8922?A, Revision 2
Project stage: Other
2024-06-24
[Table View] |
Text
October 24, 2025 George Wilson Senior Vice President, Regulatory Affairs TerraPower, LLC 15800 Northup Way Bellevue, WA 98008
SUBJECT:
TERRAPOWER, LLC - FINAL SAFETY EVALUATION FOR NAT-8922 "REACTOR SEISMIC ISOLATION SYSTEM QUALIFICATION TOPICAL REPORT," REVISION 2 (EPID NO. L-2024-TOP-0005)
Dear George Wilson:
By letter dated March 8, 2024, TerraPower, LLC (TerraPower) submitted topical report (TR)
NAT-8922, Reactor Seismic Isolation System Qualification Topical Report, Revision 0 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24068A212) to the U.S.
Nuclear Regulatory Commission (NRC) staff. The TR provides an overview and description of the seismic isolation system qualification methodology for the Natrium reactor design. On April 17, 2024, the NRC staff found that the material presented in the TR provides technical information in sufficient detail to enable the NRC staff to conduct a detailed technical review (ML24101A200). On October 22, 2024, the NRC staff issued an audit plan to TerraPower (ML24297A136) and subsequently conducted an audit of materials related to the TR from November 8, 2024, to June 11, 2025. On June 30, 2025, the NRC staff issued the audit summary (ML25202A050). On July 10, 2025, TerraPower submitted a revision of the TR (ML25195A156), which superseded the prior TR submission.
The enclosed final safety evaluation (SE) is being provided to TerraPower, because the NRC staff found NAT-8922, Revision 2, acceptable for referencing the licensing actions to the extent specified and under the limitations and conditions delineated in the TR. The final SE defines the basis for the NRC staffs acceptance of the TR.
The NRC staff requests that TerraPower publish an approved version of this TR within 3 months of receipt of this letter. The approved version should incorporate this letter and the enclosed SE after the title page. The approved version should include a -A (designating approved) following the TR identification symbol.
If you have any questions, please contact Stephanie Devlin-Gill at (301) 415-5301 or via email at Stephanie.Devlin-Gill@nrc.gov.
Sincerely,
/RA/
Joshua Borromeo, Chief Advanced Reactor Licensing Branch 1 Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation Project No.: 99902100
Enclosure:
As stated cc: TerraPower Natrium via GovDelivery
Pkg: ML25296A226 Letter: ML25296A227 Enclosure (Public): ML25296A229 Enclosure (Non-Public): ML25296A228 OFFICE NRR/DANU/UTB2:BC NRR/DANU/UAL1:PM NRR/DANU/UAL1:LA NAME CdeMessieres (GOberson for)
SDevlin-Gill DGreene DATE 06/18/2025 10/23/2025 06/30/2025 OFFICE NRR/DANU/UAL1:BC NAME JBorromeo DATE 10/24/2025