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:
r operations personnel. Fresh air supply intakes to areas containing equipment or systems important to safety should be located away from the exhaust air outlets and smoke vents of other fire areas to minimize the possibility of contaminating the intake air with the products of combustion. DG-1359, Page 64 Where total-flooding gaseous fire suppression systems are used, area intake and exhaust ventilation dampers should be controlled in accordance with NFPA 12, NFPA 12A, or NFPA 2001 to maintain the necessary gas concentration (see also Regulatory Position 3.3.2 of this guide). 4.1.4.1 Combustibility of Filter Media Filters for particulate and gaseous effluents may be fabricated of combustible media (e.g., HEPA and charcoal filters). The ignition and burning of these filters may result in a direct release of radioactive material to the environment or may provide an unfiltered pathway upon failure of the filter. Filter combustion may spread fire to other areas. Engineered safety feature filters should be protected in accordance with the guidelines of RG 1.52, “Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Post-Accident Engineered-Safety-Feature Atmosphere Cleanup System Light-Water-Cooled Nuclear Power Plants” (Ref. 102). Any filter that includes combustible materials and is a potential exposure fire hazard that may affect components important to safety should be protected as determined by the fire hazards analysis. 4.1.4.2 Smoke Control and Removal Smoke from fires can be toxic and corrosive and may obscure visibility for emergency egress and access to plant areas. Smoke control and removal may be necessary to support manual suppression activities and safe-shutdown operations. The installation of automatic suppression systems to limit smoke and heat generation should be considered. Smoke and corrosive gases should generally be discharged directly outside to an area that will not affect plant areas important to safety. The