Document: NUREG-0800
Document ID: 4e1d86bd-74a5-4678-8bc0-ffce3ba28ea0
Document Type: srp
Title: RISK-INFORMED INSERVICE TESTING
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0428/ML042880272.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.7
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CFR Title: 

Content:
relief from provisions of NRC approved Codes. The licensee should have included in the RI-IST program submittal the necessary exemption requests, technical specification amendment requests, and relief requests necessary to implement their RI-IST program. 5. Scope, Level of Detail, and Quality of the PRA for 1ST Application The quality of a PRA required for RI-IST is commensurate with the role the PRA plays in the determination of test strategies. The licensee's submittal should document how this quality is assured. In addition, the submittal should document why the PRA quality, level of detail, and scope are appropriate for the analysis, and how the integrated decision process compensates for potential limitations in this quality, level of detail or scope. 6. Categorization of Components The identification of components as potential candidates for changes in IST intervals or test methods should be done using PRA importance measures to classify components into high and low risk contributors. The results from this importance analysis should be one of the inputs to the licensee's integrated decision-making process to help determine the safety significance of the IST components. In addition to the determination of risk importance contribution for input to the licensee's integrated decision-making process, the determination of potential risk contribution from components by PRA importance determination is useful for the following reasons: * When performed with a series of sensitivity evaluations, the PRA importance determination can identify potential risk outliers by identifying components which could dominate risk for various plant configurations and operational modes, PRA model assumptions, and data and model uncertainties. * Importance categorization can provide a useful means to identify improvements to current IST practices during the risk-informed application process by identifying components that are high risk contributors which may benefit from more frequent