Document: NRC Regulatory Guide
Document ID: 80776ca5-a83d-4667-9a94-0bffa1befa91
Document Type: regulatory_guide
Title: Fire Protection Guidelines for Nuclear Power Plants (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1221/ML12216A013.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.120
CFR Part: 
CFR Title: 

Content:
location where fixed or transient combustibles could jeopardize safety- related equipment. To accomplish this, hydrants should be Installed approximately every 250 feet on the yard main system. A hose house equipped with hose and combination nozzle and other auxiliary equipment recommended in NFPA 24, "Outside Protection," should be provided as needed, but at least every 1,000 feet. Alternatively, mobile means '6df providing hose and associated equipment, such as hose carts or trucks, may be used. When provided, such mobile equipment should be equivalent to the equipment supplied by three hose houses. Threads compatible with those used by local fire departments should be provided on all hydrants, hose couplings, and standpipe risers. 1.120-15 c. Water Sprinkler and Hose Standpipe Systems (1) Sprinkler systems and manual hose station standpipes should have connections to the plant underground water main so that no single active failure or crack in a moderate-energy line can impair both the primary and backup fire suppression systems. Alternatively, headers fed from each end are permitted inside buildings to supply both sprinkler and standpipe systems, provided steel piping and fittings meeting the requirements of ANSI B31.1, "Power Piping," are tsed for the headers up to and including the first valve supplying the sprinkler systems where such headers are part of the seismically analyzed hose standpipe system. When provided, such headers are considered an extension of the yard main system. Hose standpipe and automatic water suppression systems serving a single fire area should have independent connections to the yard main systems. Each sprinkler and standpipe system should be equipped with OS&Y flputside screw and yoke) gate valve or other approved shutoff valve and waterflow alarm. Safety-related equip- ment that does not itself require sprinkler water fire protection but is subject to unacceptable damage if wet by sprinkler water discharge should be protected by