Document: NRC Regulatory Guide
Document ID: 47b09be1-4bf8-45f9-a099-7fed871c09bd
Document Type: regulatory_guide
Title: Plant-Specific, Risk-Informed Decisionmaking: Inservice Testing (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2114/ML21140A055.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.175
CFR Part: 
CFR Title: 

Content:
this method, generic age-related failures can be identified while allowing immediate implementation for some components. For component groups that are insufficient in size to test one component every refueling outage, the implementation of the interval should be accomplished in a more gradual stepwise manner. The RI-IST program should justify the selected test frequency for LSSCs that are to be tested on a staggered basis. The licensee should perform the following: a. For components that will be tested in accordance with the test frequency and method requirements specified in the OM Code of Record for the current 120-month IST program interval or OM Code Cases approved in RG 1.192 as incorporated by reference in 10 CFR 50.55a, no specific implementation schedule needs to be provided to the NRC as part of the 10 CFR 50.55a(z)(1) alternative request. The licensee’s RI-IST program should document the test frequency and method. b. For components that will tested by other methods, the licensee’s 10 CFR 50.55a(z)(1) alternative request for the proposed RI-IST program should describe the test strategies (i.e., interval extension plan and test methodology). The licensee should increase the test interval for components in a stepwise manner (i.e., equal or successively smaller steps, not to exceed one refueling cycle per step). If no significant time-dependent failures occur, the interval can be gradually extended until the component is tested at the maximum proposed extended test interval. An acceptable approach is to group similar components and test them on a staggered basis. Guidance on grouping components appears in Position 2 of NRC Generic Letter 89-04, “Guidance on Developing Acceptable Inservice Testing Programs,” dated April 3, 1989 (Ref. 24), for check valves, and in Supplement 6 to NRC Generic Letter 89-10 and Section 3.5 of ASME Code Case OMN-1 (Ref. 25) for MOVs, as well as in other NRC-endorsed documents. 3.3 Performance Monitoring Performance