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:
n the licensee’s RI-IST program. The RI-IST program description should summarize all testing to be performed on a group of components (e.g., MOV testing in response to NRC Generic Letter 96-05). The licensee’s RI-IST program plan should delineate the specific testing to be done on each component (or group of components). 3.2 Implementation Program The applicable OM Code generally requires that safety-related components within the program scope, as defined in the current OM Code, be tested on a specific frequency regardless of safety significance. The RI-IST program if authorized in accordance with 10 CFR 50.55a(z)(1) will allow the extension of certain component testing intervals and modification of certain component testing methods based on the determination of individual component importance. The implementation of the program will involve scheduling test intervals based on the results of probabilistic analysis and deterministic evaluation of each individual component. The RI-IST program should distinguish between HSSCs and LSSCs for testing intervals. All components in the RI-IST program should be individually specified in the 10 CFR 50.55a(z)(1) alternative request with their testing methods and intervals. The RI-IST program, as well as the implementing and test procedures should appropriately reference plant corrective action and feedback programs to ensure that testing failures are reevaluated for possible adjustment to the component’s grouping and test strategy. It may be acceptable to implement RI-IST programs on a phased approach. Subsequent to the authorization of an RI-IST program, the licensee implements interval extensions for LSSCs, and this may take place on a component, train, or system level. However, the NRC will generally not authorize immediately adjusting the test intervals of LSSCs to the maximum proposed test interval. Normally, test interval increases will be done stepwise, with gradual extensions permitted, consistent with cumulative