Document: NUREG-0800
Document ID: e32f0820-4e33-476e-aa36-4ca8c2c64af0
Document Type: srp
Title: Use of Probabilistic Risk Assessment in Plant-Specific, Risk-Informed Decisionmaking:
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0119/ML011940192.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.0
CFR Part: 
CFR Title: 

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dundancy; * significantly changes operations that affect the likelihood of undiscovered failures; SRP 19-Dl 0 significantly affects the basis for successful safety function; or * could create "special circumstances" under which compliance with existing regulations may not produce the intended or expected level of safety and plant operation may pose an undue risk to public health and safety. Non-risk-informed license amendment requests judged to have the potential to significantly affect risk would be referred for a more detailed risk evaluation as part of the license amendment review. Review Guidance and Procedures For license amendment requests referred for a risk review, the reviewers should assess the requested changes, and the need for and the effectiveness of any compensatory measures that might be warranted .)ecause of risk considerations, by evaluating the changes relative to the safety principles anid integrated decisionmaking process defined in Regulatory Guide (RG) 1.174. The risk acceptance guidelines (Sections 2.2.4 and 2.2.5 of RG 1.174) describe acceptable levels of risk increase as a function of total core damage frequency (CDF) and large early release frequency (LERF) and the manner in which the acceptance guidelines should be applied in the review and decisionmaking process. Reviewers should note that the guidelines serve as a point of reference for gauging risk impact but are not legally binding requirements. For non-risk-informed license amendment requests, the preliminary assessment would be qualitative, with a decision based on engineering judgment, since quantitative risk information would not generally be presented in submittals that are not risk informed. If "special circumstances" are believed to exist, the reviewers will explore in more detail the underlying engineering issues contributing to the risk concern, and the potential risk significance of the license amendment request. The staff should inform and engage the licensee as early as