Document: NRC Regulatory Guide
Document ID: 2459a562-8984-421c-8058-d096dbb9617c
Document Type: regulatory_guide
Title: Guidelines for Categorizing Structures, Systems, and Components in Nuclear Power Plants According to Their Safety Significance
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0314/ML031430373.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.201
CFR Part: 
CFR Title: 

Content:
RA types of analyses, such as a margins-type study, used in the categorization process. The licensees must explicitly address and document in their plant-specific submittal to the NRC, the adequacy of these non-PRA types of analyses and ensure that they appropriately reflect the as- built, as-operated plant and that any new information (e.g., new seismic hazard information, cable routing credited in fire analysis) does not invalidate their results. 7. Section 4 The NRC has not yet formally endorsed ASME Code Case N-658. The NRC staff review of the ASME Code Cases is expected to be completed prior to promulgating 10 CFR 50.69. The NRC staff notes that staff positions on the ASME Code Cases are provided in regulatory guides referenced in 10 CFR 50.55a. If and when endorsed by the NRC, the ASME risk-informed Code Cases on categorization and treatment will satisfy the applicable portions of the proposed 10 CFR 50.69. However, at this time, the licensee cannot assume that using this method will be acceptable to the NRC. NEI 00-04 does not provide a description of a methodology for categorization that addresses the passive pressure boundary (i.e., pressure retention capability) for the purpose of exempting SSCs from special treatment requirements in sufficient detail for the staff to endorse. Therefore, the endorsement of NEI 00-04 does not adopt any method to categorize the safety significance of the passive pressure boundary of SSCs. Until such a methodology is endorsed by the NRC, to support the categorization of SSCs, the licensee is required to describe in their plant-specific submittal requesting to implement 10 CFR 50.69, their methodology for addressing the passive pressure boundary of SSCs. 8. Section 5 The first decision block in Figure 5-1 refers to prevention or mitigation of core damage. To be consistent with the intent of the safety significance categorization process, this first decision block should be broader in scope and include the prevention or