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:
the applicable regulations in 10 CFR Part 50 and 10 CFR Part 52. However, these PRA standards do not address how to meet the requirements for an acceptable PRA. Because the joint ASME and ANS national consensus PRA standards use the term “requirement,” “require,” and other similar mandatory language, the staff’s endorsement, including its exceptions, mirrors this language. The use of this language in this RG does not mean that compliance with this RG is mandatory or is the only way to meet the statutory and regulatory requirements, or that these requirements would be applied to licensees absent their adoption and consistent with Management Directive 8.4, “Management of Backfitting, Forward Fitting, Issue Finality and Information Requests” (Ref. 41). Regulatory Position C.2.1 of this RG provides the staff position on the use of a national consensus PRA standard to meet Regulatory Position C.1. To demonstrate acceptability of the PRA for this purpose, a peer review is important for determining whether the underlying purpose of requirements in the national consensus PRA standard are met, as endorsed by the NRC with exceptions, so that it can be demonstrated that the PRA model conforms to Regulatory Position C.1. Regulatory Position C.2.2 presents the staff position on the use of PRA peer reviews to this effect, including staff endorsement with RG 1.247, Page 55 exceptions, of related industry PRA peer review guidance. When the peer review accounts for Regulatory Position C.2.2 and the PRA is assessed against a national consensus PRA standard consistent with Regulatory Positions C.1 and C.2.1, including staff exceptions, this represents an acceptable peer review process. The NRC staff considers the PRA acceptable for supporting the application based on the results of the peer review, resolution of the Facts and Observations (F&Os), and how the PRA conforms to the requirements in the national consensus PRA standards. Use of the ASME/ANS NLWR PRA standard