ML24262A010

Comment (1) of Victoria K. Anderson on Level 3 Probabilistic Risk Assessment Project Documentation (Volume 7)

ML24262A010
Person / Time
Site:	Nuclear Energy Institute
Issue date:	09/17/2024
From:	Anderson V Nuclear Energy Institute
To:	Office of Administration
References
NRC-2024-0116, 89FR58805 00001
Download: ML24262A010 (1)

Text

9/18/24, 7:01 AM blob:https://www.fdms.gov/10128407-9e67-41a7-b68a-1e924175be0d SUNSI Review Complete As of: 9/18/24, 7:01 AM Template=ADM-013Received: September 17, 2024 E-RIDS=ADM-03 PUBLIC SUBMISSIONADD: Alan Kuritzky, Status: Pending_Post Sietze Rotton, Brian Tracking No. m16-s9mi-hx3t Wagner, Mary Neely Comments Due: September 17, 2024 Comment (1) Submission Type: Web Publication Date:

7/19/2024 Docket: NRC-2024-0116 Citation 89 FR 58805 Level 3 Probabilistic Risk Assessment Project Documentation (Volume 7)

Comment On: NRC-2024-0116-0001 Level 3 Probabilistic Risk Assessment Project Documentation (Volume 7)

Document: NRC-2024-0116-DRAFT-0001 Comment on FR Doc # 2024-15251

Submitter Information

Email: smp@nei.org Organization: Nuclear Energy Institute

General Comment

See attached file(s)

Attachments

09-17-24_NEI Comments on NRC Draft Report on the Level 3 PRA Project

blob:https://www.fdms.gov/10128407-9e67-41a7-b68a-1e924175be0d 1/1 Victoria K. Anderson Phone: 202.739.8101 Technical Advisor Email: vka @nei.org Engineering and Risk

September 17, 2024

Office of Administration Mail Stop: TWFN - 7 - 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 7: Dry Cask Storage PRA, Docket ID NRC-2024- 0116

Project Number: 689

Submitted via regulations.gov

Dear Program Management,

Announcements, and Editing Staff,

On July 8, 2024, 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 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. In those comments, 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

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 Nuclear Energy Institute September 17, 2024 Page 2

consider sunsetting the project absent identification of clear regulatory applicability or benefit to public safety and security.

Additionally, NEI has several observations about the draft Volume 7 report specifically. NEI encourages the NRC to consider these perspectives, and the attached detailed comments, in any future actions or plans regarding the Level 3 PRA Project.

• This report reinforced that for dry cask storage operations, PRA is not a particularly useful tool beyond providing a demonstration that the associated risks are very low. In this study, no new failure sequences were identified, and no event sequences were found to be more significant that previous analyses revealed. The study confirms that the risks are extremely low and demonstrate that there is little value in attempting to apply PRA for risk-informed decision making beyond the understanding that the risks are negligible in comparison to regulatory standards

• Volume 7 showed substantial uncertainties in the results, with the 95th and 5th percentile occasionally spanning several orders of magnitude. For example, the Probability of Failure from the Post Accident Exhaust and HVAC System spans four orders of magnitude between the 95th and 5th percentile (from 3E-7 to 2E-3). Section 3.7 of the report acknowledges this, stating that model uncertainty represents a limitation of the results. These uncertainties may be significant, especially given the results of low risk from dry cask storageOne issue with the analysis is the lack of DCS specific data which is identified as one of the main sources of model uncertainty in the overall study. This indicates that Dry Cask PRA methods are not sufficiently advanced to support regulatory application, and are of little practical use.

• The conclusions of the report reinforce that dry cask operations are extremely low risk. Section 3.8 specifically states that regardless of the consequence metric used, the risk from DCS operations is very low. This is driven both by low frequencies of release and low source terms. Expending resources on quantifying these risks in detail offers little additional insight on dry cask operations, and should not be pursued by either the NRC or the industry.

Thank you for the opportunity to provide industrys views on this draft report. If you have any questions or require additional information, please do not hesitate to contact m e.

Sincerely,

Victoria K. Anderson, Technical Advisor Engineering and Risk

C: Alan Kuritzky, RES Jonathan Evans, RES