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:
nce in RG 1.174 in several staff regulatory positions. Additionally, the staff revised this guide to (1) adopt the term “PRA acceptability,” and related phrasing variants, instead of terms such as “PRA quality,” “PRA technical adequacy,” and “technical adequacy” to describe the appropriateness of the PRA used to support risk-informed licensing submittals; (2) update Regulatory Position C.2.2.3, “Evaluation of Risk Impact,” of this RG to be consistent with Section C.2.3 in RG 1.174, which provides specific considerations with respect to determining the acceptability of the PRA used in risk-informed decisionmaking; and (3) incorporate guidance related to the OM Code for the inservice testing of pumps and valves at commercial nuclear power plants. Background Both the NRC and the nuclear industry recognize that PRA has evolved to the point that it can be used increasingly as a tool in regulatory decisionmaking. After the publication of its policy statement on the increased use of PRA in nuclear regulatory activities, titled “Use of Probabilistic Risk Assessment Methods in Nuclear Activities: Final Policy Statement” (Ref. 11), the Commission directed the NRC staff to develop a regulatory framework that incorporated risk insights. The staff articulated that framework in SECY-95-280, “Framework for Applying Probabilistic Risk Analysis in Reactor Regulation,” November 27, 1995 (Ref. 12). This RG, which addresses IST of pumps and valves, and its companion regulatory documents implement, in part, the Commission’s policy statement and the staff’s framework by allowing risk insights to be incorporated into the operation of nuclear power plants. Licensees may submit requests to use RI-IST programs as alternatives to existing IST programs under 10 CFR 50.55a(z)(1). The Commission’s policy statement on PRA encourages greater use of this analysis technique to improve safety decisionmaking and regulatory efficiency. In response to the policy