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:
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 NLWR PRA standard. In addition to the guidance in NEI 20-09, Revision 1, the ASME/ANS NLWR PRA standard also presents the general requirements for a peer review to determine whether the PRA methodology and its implementation meet the technical requirements in the standard. The NLWR PRA standard, as endorsed by the NRC with exceptions, includes requirements for establishment of a peer review process, PRA peer review team qualifications, and documentation. The NRC staff reviewed NEI 20-09, Revision 1, to determine whether the peer review process described therein is acceptable for establishing the acceptability of a PRA. For the reasons given below, the staff finds that the guidance in NEI 20-09, Revision 1, is acceptable in that regard and endorses NEI 20-09, Revision 1, without exception. The ASME/ANS NLWR PRA standard contains requirements for the performance of an acceptable peer review process. The staff reviewed the requirements and takes no exceptions to them. The process described in NEI 20-09, Revision 1, is considered to be acceptable for a peer review performed for a PRA representing any stage of a plant’s life cycle, recognizing the varying level of detail in the PRA to account for effects such as the certainty of the design and the availability of plant-specific data. The peer review process endorsed in this section can accommodate any scope of PRA peer review, as defined by the user, including a focused-scope peer review for a PRA upgrade. The following are important aspects of NEI 20-09 the staff considered when evaluating the guidance document for endorsement. As part of an application, an applicant or licensee should describe the measures it has taken to ensure that the design-specific or plant-specific PRA is acceptable for its intended use. The