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:
detail, conformance with the NRC regulatory position in Section C of this RG, and representation of the modeled plant. This RG provides guidance to licensees on how to meet the regulatory positions in Section C for determining the acceptability of the base PRA used in support of a risk-informed regulatory activity. It also endorses, with staff exceptions and clarifications, the national consensus PRA standards, and industry guidance on how to perform a PRA peer review process. National consensus PRA standards have been developed by the ASME and ANS. In February 2009, ASME and ANS jointly issued ASME/ANS RA-Sa-2009, “Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications,” referred to hereafter as the ASME/ANS Level 1/LERF PRA standard. The ASME/ANS Level 1/LERF PRA standard is for an at-power, Level 1 and limited Level 2 PRA of internal and external hazards for LWRs. Appendix A of this RG provides the staff endorsement, with exceptions and clarifications, of the requirements in ASME/ANS RA-Sa-2009 and does not change the staff’s endorsement from RG 1.200, Revision 2. The staff’s endorsement, with exceptions and clarifications, is based on the staff’s review of the requirements in the ASME/ANS Level 1/LERF PRA standard against the related regulatory position in Section C of this RG. As stated above, because these PRA standards use the terms “requirement,” “require,” and other similar mandatory language, the staff’s endorsement, including staff exceptions and clarifications, mirrors this language. However, the use of this language in this RG is not intended to convey a regulatory requirement or suggest that these standards are the only way to meet the statutory and regulatory requirements. Additionally, in November 2017, ASME and ANS jointly issued 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