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:
oors"). Where gas suppression systems are installed, the drains should be provided with adequate seals or the gas suppression system should be sized to compensate for the loss of the suppression agent through the drains. Drains in areas containing combustible liquids should *have provisions for preventing the spread of the fire throughout the drain system. Water drainage from areas that may contain radioactiv- ity should be collected, sampled, and analyzed before discharge to the environment. (10) Floors, walls, and ceilings separating fire areas should have a minimum fire rating of three hours. Openings through fire barriers around conduit or piping should be sealed or closed to provide a fire resistance rating at least equal to that required of tt• barrier itself. Door openings should be protected with equivalently rated doors, frames, and hardware that have been tested and approved by a nationally recognized laboratory. Such doors should be normally closed and delay-alarmed with alarm and annunciation in the control room, locked closed, or equipped with automatic self-closing devices using magnetic hold-open devices that are activ- ated by smoke or rate-of-rise heat detectors protecting both sides of the opening. The status of doors equipped with magnetic hold-open devices should be indicated in the control room. Fire barrier openings for ventilation systems should be protected by a "fire door damper" havi~ng a rating equivalent to that required of the barrier (see NFPA 80, "Fire Doors and Windows"). Flexible air duct coupling in ventilation and filter systems should be noncombustible. (11) Personnel access routes and escape routes should be provided for each fire area. Stairwells outside primary containment serving as escape routes, access routes for firefighting, or access routes to areas containing equipment necessary for safeshutdown should be enclosed in masonry or concrete towers with a minimum fire rating of two hours and self-closing Class B fire doors.