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:
ve of the PRA element. HLRs are defined in general terms, should be met regardless of the CC, and accommodate different approaches. SRs are defined for each HLR and are the minimum requirements needed to satisfy the HLR. Consequently, a determination of whether an HLR is met is based on whether the associated SRs are met. Whether every SR is needed for an HLR RG 1.247, Page 56 depends on the application and is determined by the related process requirements. If any SRs are determined to be inapplicable, justification for such a conclusion should be documented and peer reviewed. All SRs related to new developed methods (NDMs) should be evaluated during peer reviews of NDMs. If different requirements are used, other than those in an established national consensus PRA standard, then it should be demonstrated how these different requirements are reasonable and acceptable for assessing and establishing what an acceptable PRA should include, as well as what acceptable processes should include. It should also be demonstrated how the different requirements meet the regulatory positions in Section C of this RG. C.2.2 Industry Peer Review Program A peer review of the PRA is performed to determine whether the requirements established in the national consensus PRA standard, as endorsed by the NRC with exceptions, have been met. An acceptable peer review approach is one that follows an established process and is done by qualified personnel, documents the results, and identifies both strengths and weaknesses of the PRA. The ASME/ANS NLWR PRA standard requires a peer review to be performed on the PRA model, any PRA upgrades, and the use of any NDMs. A peer review methodology (i.e., process) is documented in the industry-developed peer review guidance documents. This section of the RG endorses on a trial basis the process for performing PRA peer reviews provided in NEI 20-09, Revision 1, as one acceptable approach for determining whether a PRA meets the requirements in the ASME/ANS