Document: NUREG-0800
Document ID: 817bb0ad-6fd7-433e-aa2b-b4b3e1166f9c
Document Type: srp
Title: PROBABILISTIC RISK ASSESSMENT AND SEVERE ACCIDENT EVALUATION FOR
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0717/ML071700652.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.0
CFR Part: 
CFR Title: 

Content:
ions) from that review, disposition of those findings, and the relevance of that review to the technical adequacy of the current plant-specific PRA, (2) a discussion of the scope, level of detail, and technical adequacy needed to support 5 The issue of T-H uncertainties arises from the “passive” nature of safety-related systems used for accident mitigation. Passive safety systems rely on natural forces, such as gravity, to perform their functions. Such driving forces are small compared to those of pumped systems, and the uncertainty in their values, as predicted by a “best-estimate” T-H analysis, can be of comparable magnitude to the predicted values themselves. Therefore, some accident sequences with a frequency high enough to impact results, but which are not predicted to lead to core damage by a best-estimate T-H analysis, may actually lead to core damage when T-H uncertainties are considered in the PRA models. 19.0-10 Revision 2 - June 2007 the specific uses and risk-informed applications, (3) a discussion regarding the method used for determination of technical adequacy for pertinent PRA scope areas for which the NRC has not endorsed PRA standards (i.e., identify the guidance and good practices documents relied upon to determine the technical adequacy of the PRA), (4) a discussion on the use of and criteria for independent peer reviews, and (5) a discussion on the process for dispositioning independent peer review findings and maintaining or upgrading the PRA, as appropriate, to ensure that it reasonably reflects the as- designed, as-built, and as-operated plant, including the corrective action and feedback mechanisms involving the periodic evaluation of the PRA, consistent with its uses and risk-informed applications, on the basis of actual plant-specific equipment, train, and system performance and relevant industry operational experience. As noted in Element 1.1 of Table A-1 in Appendix A to Regulatory Guide 1.200, special emphasis should be placed