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:
that the models reflect the as-designed, as-to-be-built, as-to-be-operated plant, or the as-built and as-operated plant. Additionally, the peer reviewers perform independent walkdowns, if possible, to confirm PRA inputs, especially for external hazard PRAs. Assumptions are also reviewed to determine whether they are appropriate and to assess their impact on the PRA results and insights. The PRA results are checked for fidelity with the model structure and for consistency with the results from PRAs for similar plants, if available. Finally, the peer review process also examines the procedures or guidelines established for upgrading and updating the PRA to reflect changes in plant design, operation, or experience. The peer review team qualifications are important for determining the credibility, independence, and acceptability of the team members. To avoid any perception of a technical conflict of interest, the members of the peer review team should be prohibited from peer reviewing any portion of the PRA on which they have performed or supervised efforts. Each member of the team should have technical expertise in the PRA elements they review, including experience in the specific methods used to develop elements of the PRA. Each member of the peer review team should be knowledgeable about the peer review process, including the desired characteristics and attributes used to assess the acceptability of the PRA. The staff recognizes that when an applicant conducts a peer review or seeks an independent assessment of the acceptability of PRAs performed during the preoperational stage, the independent review team will likely not have specific and detailed knowledge of all aspects of the design, but members should be familiar with the general design and operating philosophy based on the design and operating guidance available for that stage of the plant life cycle. Chapter 4 of NEI 20-09, Revision 1, and Section 6.2 of the ASME/ANS NLWR PRA standard provide specific