Document: NRC Regulatory Guide
Document ID: 22ccfd5e-c5d8-4615-a02c-32369aa9f533
Document Type: regulatory_guide
Title: Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1930/ML19308B636.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.200
CFR Part: 
CFR Title: 

Content:
ppendix B, Page B-4 Table B-1. Staff Position on ASME/ANS RA-S Case 1, “Case for ASME/ANS RA-Sb-2013 Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment of Nuclear Power Plant Applications,” Technical and Peer Review Requirements of a Level 1, Seismic PRA for the At-Power Operating Mode Index No Issue Position Resolution seismic hazard analysis (PSHA), which may directly incorporate site response analyses, is used to assess horizontal ground motions at the site.” It does not seem appropriate to highlight a specific aspect of the PSHA, particularly in such an ambiguous manner. General comments on the SHA Technical Element The Code Case proposes definitions for the terms primary hazard and Secondary hazard. However, the Code Case only uses the term primary hazard in the definition of the term secondary hazard, which may not prompt a need to define the term primary hazard. The primary hazard described by the objectives in Section 5- 2.1 seems to be the vibratory ground motion. However, in many instances, but not all, the text refers to secondary hazards from vibratory ground motions. It is unclear whether there is a difference between the way vibratory ground motion is referred to in primary and secondary hazards or if these are intended to be synonymous. Consideration should be given to whether the definition be made more precise to the hazards, Clarification • Ensure consistent use of the term secondary hazards with the definition. • To the extent possible express which secondary seismic hazards are included or, alternatively, which are not. DG-1362, Appendix B, Page B-5 Table B-1. Staff Position on ASME/ANS RA-S Case 1, “Case for ASME/ANS RA-Sb-2013 Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment of Nuclear Power Plant Applications,” Technical and Peer Review Requirements of a Level 1, Seismic PRA for the At-Power Operating Mode Index No Issue Position Resolution primary or secondary, that