Document: NRC Regulatory Guide
Document ID: 8e45dce1-e1e7-4415-b1dd-7e2a610e545b
Document Type: regulatory_guide
Title: Fire Protection for Nuclear Power Plants (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2023/ML20231A835.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.189
CFR Part: 
CFR Title: 

Content:
areas. In either case, the alternative shutdown capability should be independent of the specific fire areas and should accommodate post-fire conditions when offsite power is available and when offsite power is not available for 72 hours. The licensee should provide procedures to implement the alternative or dedicated shutdown capability, as described in Regulatory Position 5.5 of this guide. The licensee should consider one spurious actuation or signal to occur before control of the plant is achieved through the alternative or dedicated shutdown system for fires in areas that require alternate or dedicated shutdown. After the operators transfer control from the control room to the alternative or dedicated shutdown system, single or multiple spurious actuations that could occur in the fire-affected area should be considered, in accordance with the plant’s approved FPP. The approach outlined in Appendix D to NEI 00-01, Revision 4, provides an acceptable methodology for evaluating alternative and dedicated shutdown, when applied in conjunction with this RG. In addition, the second paragraph of Appendix G to NEI 00-01, Revision 4, provides information on the analysis of multiple spurious actuations for alternative and dedicated shutdown systems. 5.4.2 Loss of Offsite Power/Station Blackout In evaluating the ability to accomplish safe-shutdown after fires, the licensee should consider whether offsite power will be available. However, the licensee need not consider loss of offsite power for a fire in nonalternative or nondedicated shutdown areas, if it can show that offsite power cannot be lost because of a fire in that area. As described in Regulatory Position 5.4.1 of this guide, alternative shutdown capability should accommodate post-fire conditions when offsite power is available and conditions when offsite power is not available for 72 hours. In an evaluation of safe-shutdown circuits, the availability of uninterrupted power (i.e., offsite power remains available)