Document: NUREG-0800
Document ID: 7916b088-fb90-4163-84fe-027bd315bcc5
Document Type: srp
Title: REVIEW OF RISK INFORMATION USED TO SUPPORT PERMANENT PLANT-
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0717/ML071700658.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.2
CFR Part: 
CFR Title: 

Content:
ing evaluations and probabilistic information. Regulatory Guide 1.174, Section 2.2 describes the specific evaluations that the licensee is expected to perform. The scope and quality of the engineering analyses conducted to justify a proposed change should be appropriate for the nature and 19.2-8 June 2007 scope of that change. Regulatory Guide 1.174, Section 3 describes the various types of traditional engineering and probabilistic information that should be included in submittals. The results of this element should be reviewed to determine if the submittal satisfies the following principles for risk-informed decisionmaking: the proposed change meets current regulations (unless the change is explicitly related to a requested exemption or rule change); the defense-in-depth philosophy is maintained; sufficient safety margins are maintained; and proposed increases in core damage frequency and/or risk (if any) are small and are consistent with the intent of the Commission’s Safety Goal Policy Statement (51 FR 28044). III.2.1 Evaluation of Defense-in-Depth Attributes and Safety Margins Reviewers should assess the licensee’s engineering evaluations to confirm that the principles identified in Subsection II of this SRP section are not compromised. These evaluations should include not only the traditional design basis accident (DBA) analyses, but also evaluations of the defense-in-depth attributes of the plant, safety margins, and risk assessments performed to obtain risk insights and to quantify the impact of the proposed change. III.2.1.1 Defense in Depth Defense in depth is defined as a philosophy that ensures that successive measures are incorporated into the design and operating practices for nuclear plants to compensate for potential failures in protection and safety measures. In risk-informed regulation, the intent is to ensure that the defense-in-depth philosophy is maintained, not to prevent changes in the way defense in depth is achieved. The defense-in-depth