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: 

Content:
ld be important if common cause failures ,)- human dependencies are considered. c. Evaluation Findings Reviewers should verify that the information provided and review activities conducted support the following conclusions: * The change is appropriately modeled and is properly quantified. The licensee has satisfactorily established that conclusions are not adversely affected by truncation either because (i) the change in risk from the application was calculated by the requantification of the base model, or (ii) if model requantification was not performed, or if the application depended on the risk ranking of SSCs from a pre-solved cutset equation, the following apply: The truncar:ion criterion is sufficiently low to ensure stable results, that is, the magnitude of the CDF or release frequency will not change as a result of lower truncation limits, and the grouping of SSCs into risk categories will not be affected. SRP 19-A20 The components affected by the application are, for the most part, not truncated out of the model. In cases where they are, a qualitative assessment can demonstrate the reasons why they are unimportant to risk. A. 10 Modeling of Containment Response and Changes in Large Early Release Frequency a. Areas of Review The purpose of this section is to provide guidance for use in reviewing the licensee's evaluation of changes in LERF stemming from proposed changes to the plant's design or operations. In general, only a subset of CDF sequences will be affected by a change. Whether or not this subset contributes significantly to LERF depends on several plant-specific characteristics. This section focuses on the characteristics that strongly affect LERF, and identifies review approaches based on these characteristics. It also provides guidance to help reviewers identify the major items related to functional plant capability that directly affect the potential for large early release; to direct reviewers in establishing whether the proposed changes can