Document: NUREG-0800
Document ID: ac43f632-9db1-4857-9f56-bfba45965456
Document Type: srp
Title: * These are modifications to a plant’s design, operations, or other activities that require NRC approval. These modifica
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0232/ML023250195.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19
CFR Part: 
CFR Title: 

Content:
firm basis for the criteria is created at the first plant and when the licensee shows that plant-specific features do not invalidate the comparison. On an application-specific basis, reviewers should determine whether the definition of the system success criteria will be affected by the application-specific elements or by the elements in the same minimal cutset or accident scenario as the application-specific element. Reviewers should ensure that the success criteria are not so optimistic that they underestimate the required number of components (i.e., overestimate the size of the minimal cutset). c. Evaluation Findings In cases where conclusions are sensitive to the mission success criteria, the staff’s safety evaluation report should contain findings equivalent to the following: A technical basis has been established for the mission success criteria used in the analysis. Analytical elements of the technical basis have received an appropriate level of configuration control and quality assurance. Where comparison with analogous criteria from other plants is possible, this comparison has been justified. A.6 Use of Appropriate Data a. Areas of Review In risk-informed applications, it is important that the licensee use appropriate SSC failure data. While plant-specific data is preferred, for plants with little operating history the only choice might be the use of generic data. Furthermore, when the impact of the change is being modeled as a modification of parameter values, sufficient plant-specific data may not exist to support the modification. The data-related issues are summarized as follows: (a) if the impact of the SRP 19-A12 application is to be modeled as a change in parameter values associated with basic events representing modes of unavailability of certain SSCs, these changes should be reasonable and should be supported by technical arguments including plant-specific and generic operational information (when available) and (b) the impact of the change