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:
Part 10 of the standard. However, it should be noted, that consistent with the Commission-endorsed phased PRA Quality Initiative, all risk contributors that cannot be shown as insignificant, should be assessed using a PRA (as defined in regulatory position C.1) to support risk-informed licensing actions. DG-1362, Appendix B, Page B-1 APPENDIX B NRC REGULATORY POSITION ON THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) AND THE AMERICAN NUCLEAR SOCIETY (ANS) RA-S CASE 1 Introduction The American Society of Mechanical Engineers (ASME) and the American Nuclear Society (ANS) have published 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” (Ref. 23), which is a proposed alternative set of requirements related to requirements for a seismic probabilistic risk assessment (PRA) in Part 5 of ASME/ANS RA-Sa-2009 (Ref. 21). The standard states that it “sets forth requirements for probabilistic risk assessments (PRAs) used to support risk-informed decision for commercial nuclear power plants and describes a method for applying these requirements for specific applications.” The U. S. Nuclear Regulatory Commission (NRC) staff has reviewed ASME/ANS RA-S Case 1 against the relevant characteristics and attributes for an acceptable PRA as discussed in regulatory positions C.1 and C.2 of Section C in this RG. The staff’s position on each requirement (referred to in the standard as a requirement, a high-level requirement, or a supporting requirement) in ASME/ANS RA-S Case 1 is categorized as “no objection,” “no objection with clarification,” or “no objection subject to the following qualification,” and defined as follows: • No objection. The staff has no objection to the requirement. • No objection with clarification. The staff has no objection to the requirement. However, certain requirements, as written, are either unclear or ambiguous,