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:
I. The design considerations for shorting switches outlined in Appendix I to NEI 00-01, Revision 4, provide an acceptable methodology for shorting switch applications when applied in conjunction with this RG. 5.4 Alternative and Dedicated Shutdown Capability 5.4.1 General Guidelines Appendix R to 10 CFR Part 50 defines “alternative shutdown capability” as being provided by rerouting, relocating, or modifying existing systems, whereas “dedicated shutdown” is defined as being provided by installing new structures and systems for the function of post-fire shutdown. Since post-fire repairs cannot be credited for achieving and maintaining hot shutdown, the licensee should implement the DG-1359, Page 85 required rerouting, relocating, or modifying of the existing system for alternative shutdown capability in existing plants when the need for additional alternative shutdown capability is identified. Where alternative or dedicated shutdown capability is required, the licensee should provide fixed fire suppression and detection for the fire area or zone containing the redundant success paths (detection and suppression are not necessarily required for the area or zone containing the alternative or dedicated shutdown system except where required by the fire hazards analysis). The safe-shutdown analysis should demonstrate that alternative or dedicated shutdown systems and components, including electrical circuits, necessary to achieve and maintain hot shutdown are free of fire damage and capable of performing the necessary safe-shutdown functions or are prevented from causing actions that prevent safe shutdown. The alternative or dedicated shutdown capability for specific fire areas may be unique for each such area, or it may be one combination of systems for all such 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