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:
measurement strategies. Each of these principles should be considered in the risk-informed, integrated decisionmaking process, as illustrated in Figure 1. RG 1.174 gives additional guidance on the key principles applicable to all risk-informed applications. RG 1.175, Page 6 Figure 1. Principles of risk-informed integrated decisionmaking Four-Element Approach to Risk-Informed Decisionmaking for Inservice Testing RG 1.174 describes a four-element process for developing risk-informed regulatory changes. This approach, shown in Figure 2, illustrates the relationships among the elements. This approach is iterative rather than sequential. The discussion below provides an overview of this process specifically related to RI-IST programs. The order in which the elements are performed may vary or occur in parallel, depending on the particular application and the preference of the program developers. Figure 2. Principal elements of risk-informed, plant-specific decisionmaking Element 1: Define Proposed Changes to the Inservice Testing Program. The purpose of this element is to identify (1) the particular components that would be affected by the proposed changes in testing practices, including those currently in the IST program and possibly some that are not (if it is determined through new information and insights such as the PRA that these additional components are important in terms of plant risk) and (2) specific revisions to testing schedules and methods for the chosen components. Plant systems and functions that rely on the affected components should be identified. Regulatory Position C.1 gives a more detailed description of Element 1. Element 2: Perform Engineering Analysis. This element uses both deterministic engineering and PRA methods to help define the scope of the changes to the IST program and to evaluate the impact of the changes on the overall plant risk. Areas that are to be evaluated include the expected effect of the proposed RI-IST program on the design