ML25317A745
| ML25317A745 | |
| Person / Time | |
|---|---|
| Site: | Nuclear Energy Institute |
| Issue date: | 10/03/2025 |
| From: | Anderson V Nuclear Energy Institute |
| To: | Office of Administration |
| References | |
| NRC-2025-0098, 90FR36454 00003 | |
| Download: ML25317A745 (1) | |
Text
PUBLIC SUBMISSION As of: 11/13/25, 2:42 PM Received: October 03, 2025 Status: Pending_Post Tracking No. mga-wbak-twot Comments Due: October 03, 2025 Submission Type: Web Docket: NRC-2025-0098 Level 3 Probabilistic Risk Assessment Project Documentation (Volume 8)
Comment On: NRC-2025-0098-0001 Level 3 Probabilistic Risk Assessment Project Documentation (Volume 8)
Document: NRC-2025-0098-DRAFT-0003 Comment on FR Doc # 2025-14701 Submitter Information Organization:Nuclear Energy Institute General Comment See attached file(s)
Attachments 10-03-25_NEI Comments on NRC Draft Report on the Level 3 PRA Project Docket ID NRC-2025-0098 11/13/25, 2:42 PM NRC-2025-0098-DRAFT-0003.html file:///C:/Users/BHB1/Downloads/NRC-2025-0098-DRAFT-0003.html 1/1 SUNI Review Complete Template=ADM-013 E-RIDS=ADM-03 ADD: Alan Kuritzky, Latonia Enos-Sylla, Susan Cooper, Mary Neely Comment (3)
Publication Date:
8/4/2025 Citation: 90 FR 36454
Victoria K. Anderson Technical Advisor Engineering and Risk Phone: 202.739.8101 Email: vka@nei.org October 3, 2025 Office of Administration Mail Stop: TWFN A60M U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Attn: Program Management, Announcements, and Editing Staff
Subject:
Industry Comments on NRC Draft Report on the Level 3 Probabilistic Risk Assessment (PRA)
Project; Volume 8: Integrated Site Risk, All Hazards, Level 1, Level 2, and Level 3 PRA, Docket ID NRC-2025-0098 Project Number: 689 Submitted via regulations.gov
Dear Program Management,
Announcements, and Editing Staff, On August 4, 2025, the U.S. Nuclear Regulatory Commission (NRC) issued a notice in the Federal Register soliciting comments on the subject draft report. The Nuclear Energy Institute (NEI)1 is pleased to provide comments on this draft report on behalf of the nuclear energy industry.
NEI previously provided comments on a draft of the Level 3 Probabilistic Risk Assessment (PRA) Project Volume 4, Overview of Reactor, At-Power, Level 1, 2, and 3 PRAs for Internal Fires, Seismic Events, and High Winds, on October 19, 2023, on the Level 3 PRA Project Volume 7, Dry Cask Storage PRA on September 17, 2024, and on Volume 6a: Spent Fuel Pool Level 1 and Level 2 PRA, and Volume 6b:
Spent Fuel Pool Level 3 PRA, on August 28, 2025. In those each of these letters, NEI suggested that NRC should reconsider the value of the Level 3 PRA Project after over a decade of resource devotion with minimal developed insights relevant to nuclear safety. The comments specifically noted that substantial uncertainties remain in the Level 3 PRA portion of the study and that there does not yet appear to be any insight to be gained from spending multiple years developing a Level 3 PRA for an operating reactor, and neither industry nor NRC resources should be invested in full-scope Level 3 PRAs for the operating fleet.
NEIs perspective on the relative value of the Level 3 PRA Project remains unchanged, and NEI again suggests that the NRC should strongly consider sunsetting the project absent identification of clear 1 The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.
Office of Administration October 3, 2025 Page 2 Nuclear Energy Institute regulatory applicability or benefit to public safety and security. Such clear regulatory applicability has not been identified, and NEI continues to suggest that this work no longer be pursued by NRC.
Additionally, NEI has several observations about the draft Volume 8 report specifically, and suggests that the report demonstrates that a realistic full multi-unit PRA is currently not feasible, and that it likely offers no additional insights beyond those identified via a systemic engineering evaluation of the site. NEI encourages the NRC to consider these perspectives in any future actions or plans regarding the Level 3 PRA Project, or multi-unit PRA work.
The study highlighted that, for a site with minimal dependencies, multi-unit risk is an order or magnitude, or more, lower than single-unit risk. Precise quantification of this risk via a full PRA model is not a valuable use of resources for sites with minimal dependencies, including the current operating fleet. Given this, multi-unit PRA should not be pursued for the operating fleet.
The key insights from the results of the multi-unit PRA - the domination of seismic risk and loss of offsite power events, in addition to the influence of shared components - were known in advance of the development of the model. The process of identifying inter-unit dependencies provided the insights for supporting decision-making, without the need for explicit modeling or quantification.
This further reinforces that multi-unit PRA should not be pursued for the operating fleet, and should not be required for new reactors.
The completion of the multi-unit PRA described in the report required multiple conservative assumptions and simplifications, demonstrating that the current models and methods do not support effective, realistic multi-unit PRA development. For example, due to lack of availability of specific data, generic coupling factors were used. Simplifications to address computational challenges rendered the approach impractical for sites with more than two units, illustrating that the current state of PRA technology only supports multi-unit PRA development via conservative assumptions. The resources required to develop realistic methods is not worth the limited risk insights gained from the resulting analysis. This again underscores that the pursuit of multi-unit PRA for the operating fleet is not appropriate.
Thank you for the opportunity to provide industrys views on these draft reports. If you have any questions or require additional information, please do not hesitate to contact me.
Sincerely, Victoria K. Anderson, Technical Advisor Engineering and Risk C:
Alan Kuritzky, RES Latonia Enos-Sylla, RES