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:
nal hazard PRA typically uses as its starting point the internal-events PRA model to which must be added a number of structures, systems, and components (SSCs) not included in the model but that could fail due to the external hazard and new failure modes caused by the external hazard for SSCs already present in the model. Both the part of the internal-events model dealing with CDF and the part dealing with LERF are used as starting points. Eliminated Subsections 5-1.4 and 5-1.5 -------------------- No objection -------------------- Eliminated Subsection 5-1.6 The Part 5 Code Case does not include the language from Section 5- 1.6 in ASME/ANS RA- Sb- 2013, which discussed the usage of generic fragility information. Section 5-1.6 in ASME/ANS RA-Sb- 2013 indicates that “(a) Analysts should apply caution in the use of generic fragilities and provide justification that the generic fragilities are applicable, and (b) Peer reviews should focus on the use of generic fragilities to ensure that their use is appropriate Clarification Include in the NMA language on the use of generic fragility information as in Section 5-1.6 in ASME/ANS RA-Sb-2013 as follows: (a) Analysts should apply caution in the use of generic fragilities and provide justification that the generic fragilities are applicable, and (b) Peer reviews should focus on the use of generic fragilities to ensure that their use is appropriate and justified. DG-1362, Appendix B, Page B-3 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 and justified. “ These statements are important because they appropriately identify the scope of interest with respect to generic fragility for both the analysts and the peer reviewers. Section 5-2