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
CFR Part: 
CFR Title: 

Content:
schedule established for testing all high and low safety significant components identified in its RI-IST program. The staff should verify that the plan contains test strategies (i.e., frequencies and methods) for high and low safety significant components that are within the scope of the licensee's RI-IST program, including those components identified as HSSCs that are not currently in the IST program. The licensee's RI-IST program should not allow the immediate increase of the test interval of all low safety significant components (LSSCs) to their maximum. Instead, a step-wise approach should be employed. One step-wise method to extend the test interval for LSSCs is to group similar components based on component type, size, manufacturer, model, and service condition and staggering the testing of the components in a group over an extended interval. Initially, it would be desirable to test at least one component in each group every refueling outage. For component groups which are insufficient in size to test one component every refueling outage, the implementation of the interval extension should be accomplished in a step-wise manner. Components whose test interval is to be extended via staggering should be identified along with their staggered frequency over the test interval. Components should also be identified that are to have their test frequency extended using some other step-wise approach. The final test interval of these components should also be noted in the submittal. 2. Performance Monitoring of IST Component Performance monitoring in RI-IST programs refers to the monitoring of inservice test data for components within the scope of the RI-IST program including both HSSC and LSSC. The purpose of performance monitoring in a RI-IST program is twofold. First, the performance monitoring should help confirm that no unexpected failure mechanisms that are related to the revised test strategy become important enough to alter the failure rates assumed in the