Letter Sequence Approval |
|---|
|
|
MONTHYEARML23272A2602023-09-29029 September 2023
Terrapower, LLC, Transmittal of Topical Report, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Revision 0
Project stage: Request
ML23352A2732023-12-18018 December 2023
NRR E-mail Capture - (External_Sender) Proposed Revised Schedule Terrapower TR (DBA) Methodology for In-Vessel Events Without Radiological Release (L-2023-TOP-0050)
Project stage: Other
ML24064A1952024-03-0505 March 2024
Public - Audit Plan - Terrapower - Design Basis Accident Methodology for In-Vessel Events Without Radiological Release - L-2023-TOP-0050
Project stage: Other
ML24145A0562024-05-22022 May 2024
Email - RAI Dates - Revised Schedule - Terrapower TR - (DBA) Methodology for In-Vessel Events Without Radiological Release (L-2023-TOP-0050)
Project stage: RAI
ML24326A3712024-11-26026 November 2024
Email: Request for Withholding from Public Disclosure - Terrapower, LLC Topical Report, NAT-9390, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Rev. 2,
Project stage: Other
ML24326A3702024-11-26026 November 2024
NRC Form 897: Request for Withholding from Public Disclosure - Terrapower, LLC Topical Report, NAT-9390, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Rev. 2
Project stage: Other
ML24255A0142024-11-27027 November 2024
Letter - Terrapower, LLC - Summary Report on the Regulatory Audit of Topical Report, TP-LIC-RPT-0004, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release Topical Report, Revision 0
Project stage: Other
ML24255A0172024-11-27027 November 2024
Enclosure (Public) - Terrapower, LLC - Summary Report on the Regulatory Audit of Topical Report, TP-LIC-RPT-0004, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release Topical Report, Revision 0
Project stage: Other
ML24358A2472024-12-23023 December 2024
Public - Terrapower, LLC - Draft Safety Evaluation for Natrium Topical Report NAT-9390, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Revision 2
Project stage: Draft Other
ML24274A3502024-12-23023 December 2024
Email - Terrapower, LLC - Draft Safety Evaluation (Public) of Topical Report, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Revision 2
Project stage: Draft Approval
ML25106A0432025-04-17017 April 2025
Public - Enclosure - Terrapower, LLC - Final Safety Evaluation of Topical Report NAT-9390, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Rev 2
Project stage: Approval
ML25106A0402025-04-17017 April 2025
Terrapower, LLC - Final Safety Evaluation of Topical Report NAT-9390, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release, Rev. 2
Project stage: Approval
ML25213A0342025-08-14014 August 2025
Email: Request for Withholding Proprietary Information from Public Disclosure - Terrapower, LLC, NAT-9390-A, Revision 2, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release
Project stage: Other
ML25212A0602025-08-14014 August 2025
Completed NRC Form 896 for -A Version Verification of Terrapower, LLC Topical Report NAT-9390, Revision 2, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release
Project stage: Other
ML25213A0332025-08-14014 August 2025
NRC 897: Request for Withholding Proprietary Information from Public Disclosure - Terrapower, LLC, NAT-9390-A, Revision 2, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release
Project stage: Other
ML25212A0612025-08-15015 August 2025
Email NRC Form 896, Terrapower, LLC Topical Report NAT-9390, Revision 2, Design Basis Accident Methodology for In-Vessel Events Without Radiological Release
Project stage: Other
2024-12-23
[Table View] |
Text
April 17, 2025 George Wilson Vice President, Regulatory Affairs TerraPower, LLC 15800 Northup Way Bellevue, WA 98008
SUBJECT:
TERRAPOWER, LLC - FINAL SAFETY EVALUATION OF NAT-9390, DESIGN BASIS ACCIDENT METHODOLOGY FOR IN-VESSEL EVENTS WITHOUT RADIOLOGICAL RELEASE, REVISION 2 (EPID NO. L-2023-TOP-0050)
Dear George Wilson:
By letter dated September 29, 2023, TerraPower, LLC, (TerraPower) submitted Topical Report (TR)
TP-LIC-RPT-0004, Design Basis Accident Methodology for In-Vessel Events without Radiological Release, Revision 0 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23272A260), which summarizes the approach taken to satisfy the guidance outlined in Regulatory Guide (RG) 1.203, Evaluation Model Development and Assessment Process (EMDAP),
for in-vessel design basis accident (DBA) events without radiological release in the Natrium reactor.
On October 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) staff determined that the TR provided sufficient information for the NRC staff to begin its detailed technical review (ML23303A168).
On March 5, 2024, the NRC staff transmitted an audit plan to TerraPower (ML24064A195) and subsequently conducted an audit of materials related to the TR from March 25, 2024, to June 27, 2024. The NRC staff issued the audit summary dated November 27, 2024 (ML24255A017). On October 11, 2024, TerraPower submitted a revision of the TR (ML24295A202), which was renumbered from TP-LIC-RPT-0004 to NAT-9390, to clarify portions of the TR as discussed in the audit summary.
The enclosed final Safety Evaluation (SE) is being provided to TerraPower, because the NRC staff has found NAT-9390, Revision 2, acceptable for referencing in licensing actions to the extent specified and under the limitations and conditions delineated in the TR and the SE. The final SE defines the basis for the NRC staffs acceptance of the TR.
The NRC staff requests that TerraPower submit to NRC staff 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 Roel Brusselmans at (301) 415-0829 or via email at Roel.Brusselmans@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: ML25106A038 Letter: ML25106A040 Public
Enclosure:
ML25106A043 Non-Public Enclosure (Proprietary - ECI): ML25106A042 OFFICE NRR/DANU/UTB2:TR NRR/DANU/UTB2:BC NRR/DANU/UAL1:PM NAME RAnzalone CdeMessieres RBrusselmans DATE 3/21/2025 4/9/2025 4/10/2025 OFFICE NRR/DANU/UAL1:LA OGC - NLO NRR/DANU/UAL1:BC NAME DGreene JEzzell JBorromeo DATE 4/14/2025 4/17/2025 4/17/2025