Document: NUREG-0800
Document ID: 32179098-f78d-4852-9c29-1e5e3abb2705
Document Type: srp
Title: RISK-INFORMED DECISION MAKING:  TECHNICAL SPECIFICATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380228.pdf
Revision Date: 2023-06
Chapter: 16
Section ID: 16.1
CFR Part: 
CFR Title: 

Content:
age (i.e., most of the TS systems modeled in a PRA other than the containment systems), Level I evaluations are needed. For containment systems, Level 2 evaluations are likely to be needed at least to the point of assessing containment structural performance 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" (Reference 19). The key areas for review of PRA considerations are addressed in the following subsections. The review of the PRA scope in evaluating a TS change 16.1-16 Revision 1 - March 2007 should ensure that the guidance of RG 1.177, Position 2.3.2, is followed. (c) Modeling Level of Detail. The review of the PRA level of detail in a TS change evaluation should ensure that the guidance of RG 1.177, Position 2.3.3.1, is followed. (d) Modeling of Initiating Events. The review of PRA initiating event modeling in a TS change evaluation should ensure that the guidance of RG 1.177, Position 2.3.3.2, is followed. (e) Screening Criteria and Truncation Limits. The review of the PRA screening criteria and truncation limits a TS change evaluation should ensure that the guidance of RG 1.177, Positions 2.3.3.3 and 2.3.3.4, is followed. (f) Assumptions in Applying PRA for TS Changes. The review of the assumptions in the PRA application to a TS change should ensure that the guidance of RG 1.177, Position 2.3.4, is followed. (g) Sensitivity and Uncertainty Analyses. The review of any sensitivity and uncertainty analyses in a TS change evaluation should ensure that the guidance of RG 1.177, Position 2.3.5, is followed. 3. Define Implementation and Monitoring Program A. Three Tiered Implementation Approach. As described in subsection IlI.2.B of this SRP section, the staff expects the licensee to use a three-tiered approach in