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:
2. Relationship of Regulatory Guide 1.200 to other risk-informed guidance Regulatory guides addressing specific applications, such as RG 1.201, allow for the use of PRAs that are not full-scope (e.g., they may not include contributions from external initiating events or LPSD modes of operation). Those RGs do, however, state that the missing PRA scope items are to be addressed in some way, such as using bounding analyses to justify excluding missing PRA scope items, or by limiting the scope of the application. This RG does not address non-PRA approaches such as bounding analyses; rather, this guide only addresses PRA approaches. Instead, NUREG-1855 provides guidance on how to perform acceptable bounding analyses and on limiting the scope of the application. Application-specific RGs have been and continue to be developed to provide guidance on the use of PRA information. For example, RG 1.174 and the related guidance in Section 19.2 of the NRC Standard Review Plan (SRP) provide general guidance on applications that address risk-informed changes to the licensing basis. Although RG 1.174 is written in the context of one regulatory activity specific to operating reactors (license amendments), its underlying philosophy and principles are applicable to a broad spectrum of reactor regulatory activities that use RG 1.200 for determining the acceptability of the base PRA. Key aspects of RG 1.174 and Section 19.2 of the NRC SRP include the following: • A description of a risk-informed integrated decision-making process that characterizes how risk information is used and, more specifically, it clarifies that such information is one element of the decision-making process. That is, decisions “are expected to be reached in an integrated fashion, considering traditional engineering and risk information, and may be based on qualitative factors as well as quantitative analyses and information.” • The recognition that the PRA developed to support regulatory decisions (i.e., as