Document: NRC Regulatory Guide
Document ID: cde52d5a-adf9-49be-9d1f-59449dfca895
Document Type: regulatory_guide
Title: TRIAL - Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2123/ML21235A008.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.247
CFR Part: 
CFR Title: 

Content:
be met, as endorsed by the NRC with exceptions, for a PRA to be considered acceptable. These consensus standards include both technical and process-related requirements, such as those related to peer review and PRA configuration control. The PRA peer review process is used to determine whether a PRA meets the requirements in the national consensus PRA standard. One acceptable approach for a peer review of a PRA is to have qualified personnel follow an established, NRC-endorsed peer review process that documents the results and identifies both strengths and weaknesses of the PRA. Use of this RG in support of an application will reduce the need for an in-depth review of the PRA by NRC reviewers, allowing them to focus on key assumptions and areas identified by peer reviewers as being of concern and relevant to the application. The acceptability of a PRA is measured against the PRA scope, level of detail, conformance with the NRC regulatory positions in Section C of this RG, and representation of the modeled plant. The ASME/ANS NLWR PRA standard provides requirements for a comprehensive probabilistic radiological risk assessment that addresses all radiological sources, all hazards, all plant operating states (POSs), and all levels of analysis (e.g., from initiating event to radiological consequence) of PRA for NLWRs. This RG provides the staff endorsement of the ASME/ANS NLWR PRA standard. Appendix A to this RG documents the bases for the staff’s endorsement, with exceptions, of the technical requirements in the standard. The staff’s endorsement, for trial use, with exceptions, is based on its review of the requirements in the ASME/ANS NLWR PRA standard against the related regulatory positions in Section C of this RG. A PRA peer review process for NLWR PRAs was developed and documented in NEI 20-09, Revision 1, which provides guidance on how to perform a PRA peer review to meet the PRA peer review requirements in the ASME/ANS NLWR PRA standard. Regulatory Position