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:
those areas that cannot readily be quantified in the following: a. The licensee’s proposed RI-IST program should be supported by both a deterministic engineering analysis and a PRA analysis. b. The licensee’s RI-IST program submittal should be consistent with the guidance contained throughout this RG, specifically with the expectations listed in this section, or the submittal should justify why an alternative approach is acceptable. RG 1.175, Page 21 3. Element 3: Define Implementation and Monitoring Program Upon approval of an RI-IST program, the licensee should have in place an implementation schedule for testing all HSSCs and LSSCs identified in its program. This schedule should include test strategies and testing frequencies for HSSCs and LSSCs that are within the scope of the licensee’s IST program and components identified as HSSCs that are not currently in the IST program. 3.1 Inservice Testing Program Changes This section discusses the test strategy changes (i.e., component test frequency and methods changes) that licensees should make as part of an RI-IST program. The RI-IST program should identify components on which the test strategy (i.e., frequency, methods, or both) should be more focused as well as components for which the test strategy might be relaxed. The information contained in, and derived from, the PRA should be used to help construct the testing strategy for components. To the extent practicable, components with high safety significance should be tested in ways that are effective at detecting their risk-important failure modes and causes (e.g., ability to detect failure, to detect conditions that are precursors to failure, and predict end of service life). Components categorized as LSSC may be tested less rigorously than components categorized as HSSC (e.g., less frequent or informative tests). In some situations, an acceptable test strategy for components categorized as HSSC may be to conduct the existing approved OM Code IST test at