Document: NUREG-0800
Document ID: 0d034ca5-ee9b-43ca-a6d6-b08e537d605b
Document Type: srp
Title: Determining the Technical Adequacy of Probabilistic Risk
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0625/ML062510220.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.1
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sions with 7 respect to the uncertainties in the analysis. There are issues for which there is no consensus on analytical models or methods of analysis. Furthermore, PRAs are models, and in that sense the developers of those models rely on certain approximations to make the models manageable and on certain assumptions to address the uncertainties concerning the modeling of certain issues. This is recognized in regulatory guides such as Regulatory Guide 1.174, which give guidance on how to address the uncertainties by, for instance, performing appropriate sensitivity analyses. This aspect is expected to be addressed in the application-specific regulatory guides and associated SRP chapters. III.2.1 Determination That the PRA Model Is Current When using risk insights based on a PRA model, the PRA model must be up to date and represent the current plant configuration and operating practices. The reviewer should confirm that the licensee has a process for updating and maintaining the PRA model that is consistent with the staff position on the process in the ASME PRA standard. The reviewer should confirm that the PRA has been revised to reflect any significant changes in design or operational practices (including operating procedures), and that the data used to estimate the parameters are current. This may be achieved by reviewing the licensee's description of their updating process and ascertaining that the licensee has adequately addressed recent plant modifications and operational changes that could have a significant impact on the results of the specific application that are not reflected in the current PRA model. III.2.2 Assessment of the Technical Adequacy of the PRA Required by the Application The parts of the PRA required by the application are to be assessed for technical adequacy. Implementation of RG 1.200 should obviate the need for staff review of the base PRA for the risk scope for which a standard and a corresponding appendix to RG 1.200 exist. A staff