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:
the PRA is maintained and upgraded, as needed, to ensure that it represents the as-designed, as-to-be-built, or as-to-be-operated plant or the as-built and as-operated plant, depending on where it is being used in the stages of plant licensing and consistent with the available plant information. In the most general sense, an application is a documented analysis based in part or in whole on a design or plant-specific PRA that is used to assist in decision-making with regard to the design, licensing, procurement, construction, operation, or maintenance of a nuclear power plant. In the context of regulatory activities, an application includes the use of PRA results to support decisions related to any regulated activity, regardless of whether the NRC or the applicant or licensee is making the decision. Therefore, a process for developing, maintaining, and upgrading an acceptable PRA is established. This process involves identifying and using plant information to develop and modify the PRA, including changes to the plant that necessitate changes to the PRA. The applicant or licensee will consider the cumulative impact of any changes to the plant and PRA model, as needed, on the results of the PRA and on any applications thereof being performed or considered between any periodic update of the PRA. Changes that would impact risk-informed decisions are addressed in the context of the application or implemented prior to the application. The process is performed such that the plant information identified and used in the PRA reflects the as-designed, as-to-be-built, or as-to-be-operated plant or the as-built and as-operated plant, as appropriate for the stage of licensing for which the PRA is being used and is as realistic as possible in assessing the risk. The information sources include the applicable design, operation, maintenance, and engineering characteristics of the plant. For those SSCs and human actions used in the development of the PRA, the following information is