Document: NRC Regulatory Guide
Document ID: 22ccfd5e-c5d8-4615-a02c-32369aa9f533
Document Type: regulatory_guide
Title: Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1930/ML19308B636.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.200
CFR Part: 
CFR Title: 

Content:
,” provides a set of technical requirements for Section 1-6 of the ASME/ANS Level 1/LERF PRA standard. NRC endorsement of this document is provided in regulatory position C.2.2.3 and C.2.2.4 of this RG. After an NDM has been successfully peer reviewed, the NDM’s implementation into a plant- specific PRA is an upgrade and would need an implementation peer review, which would follow the guidance in regulatory position C.2.2.2.1. The Glossary to this RG provides a definition for the term NDM and other related terms. Appendix C provides additional discussion about the characteristics and attributes of an NDM. An acceptable approach to performing a peer review for an NDM is the guidance in NEI 17-07, Revision 2. In particular, NEI 17-07, Revision 2, states, in part, that, if an NDM is deemed not technically acceptable in the NDM peer review report, or if one or more finding-level Facts and Observations (F&Os) on the NDM remain open, a licensee may not use it in a PRA supporting risk-informed licensing applications. If open F&Os from an NDM peer review cannot be successfully closed via an NRC- endorsed peer review process, the NDM may be submitted to the NRC to determine the acceptability of the NDM. Submitted applications that use NDMs with open F&Os related to the NDM will be subject to review by the NRC to determine acceptability of the NDM, its implementation in the PRA, and its potential impact on the application. The peer review of an NDM should meet certain requirements specific to that type of peer review. An acceptable set of requirements against which the adequacy of an NDM can be assessed is provided in PWROG-19027-NP, Revision 1. Section 5.2 of PWROG-19027-NP, Revision 1, describes features to be added to a peer review report of a plant PRA that uses NDMs and the public availability of NDM peer review reports. Section 5.3 of PWROG-19027-NP, Revision 1, provides the potential outcomes of a peer review of an NDM with respect to whether an NDM is able to