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:
model used in the risk sensitivity study of Chapter 8 must be verified to be representative of the as-built, as- operated plant and the results of this study verified to be acceptable when compared to the RG 1.174 acceptance guidelines when the PRA model is changed or other new information is made available. This provision must be incorporated into the licensee’s corrective action and/or feedback processes implemented to comply with 10 CFR 50.69. NEI 00-04 states that a multi-disciplined station management review committee could take the place of the IDP to make the final determination on changes in SSC categorization after the completion of the categorization of all scheduled SSCs. The NRC staff does not agree with this allowance. Since the IDP is established to provide the full and balanced expertise in determining the final categorization of the SSCs that a licensee categorizes under 10 CFR 50.69, any proposed changes in SSC categories must also be reviewed and accepted by the IDP at the same level of rigor and depth applied to their initial categorization under 10 CFR 50.69. 25. Section 12 The documentation retention time suggested in NEI 00-04 is 5 years after completion of the categorization process or until the plant-specific PRA and, if necessary, SSC categorization is updated. Since this documentation provides the documentation of the methodology and results of the implementation of 10 CFR 50.69 in categorizing SSCs, may be phased in over many years, and may be re-initiated after some period of time after initially completing the process for some selected SSCs, the NRC concludes that this documentation must be retained for the life of the plant. 26. Section 13 The assessment of the impact of later SSC categorizations must encompass more than just the PRA results; this assessment must also address the potential impacts on the deterministic, traditional engineering (e.g., defense-in-depth), non-PRA type analyses (e.g., seismic margins), 15 and operating