Document: NUREG-0800
Document ID: 7f6b0af0-d79e-4704-9eac-aa03109a7731
Document Type: srp
Title: RISK-INFORMED DECISIONMAKING: TECHNICAL SPECIFICATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0425/ML042520260.pdf
Revision Date: 2023-06
Chapter: 16
Section ID: 16.1
CFR Part: 
CFR Title: 

Content:
of operation will not be required for TS change applications. As a minimum, for systems used to prevent core damage (i.e., most of the TS systems modeled in a PRA other than the containment systems), Level I evaluations should be performed. For containment systems, Level 2 evaluations are likely to be needed at least to the point of assessing containment structural performance in order to estimate the LERF. When only a Level I PRA is available but additional Level 2 information is desirable, one acceptable method for approximating the needed information is proposed in NUREG/CR-6595, "An Approach for Estimating the Frequencies of Various Containment Failure Modes and Bypass Events" (Ref. 19). The key areas for review of PRA considerations are discussed in the following sections. The review of the scope of the PRA used in evaluating a TS change should ensure that the guidance contained in Regulatory Position 2.3.2 of Regulatory Guide 1.177 is followed. c) Modeling Level of Detail The review of the level of detail of the PRA used in evaluating a TS change should ensure that the guidance contained in Regulatory Position 2.3.3.1 of Regulatory Guide 1.177 is met. d) Modeling of Initiating Events The review of initiating event modeling of the PRA used in evaluating a TS change should ensure that the guidance contained in Regulatory Position 2.3.3.2 of Regulatory Guide 1.177 is met. \- Rev. 0 - August 1998 SRP 16.1-18 e) Screening Criteria and Truncation Limits The review of the PRA screening criteria and truncation limits used in evaluating a TS change should ensure that the guidance contained in Regulatory Positions 2.3.3.3 and 2.3.3.4 of Regulatory Guide 1 .177 is met. f) Assumptions in Applying PRA for TS Changes The review of the assumptions in applying the PRA to a TS change should ensure that the guidance contained in Regulatory Position 2.3.4 of Regulatory Guide 1.177 is met. g) Sensitivity and Uncertainty Analyses The review of any sensitivity and uncertainty