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:
ntial for an energetic electrical fault to damage adjacent equipment, cables, or cabinets important to safety. Rooms containing electrical cabinets important to safety should be provided with areawide automatic fire detection, automatic fire suppression, and manual fire suppression capability. Electrical cabinets containing a quantity of combustible materials (e.g., cabling) sufficient to propagate a fire outside the cabinet of fire origin should be provided with in-cabinet automatic fire detection. 4.1.4 Heating, Ventilation, and Air Conditioning Design Suitable design of the ventilation systems can limit the consequences of a fire by preventing the spread of the products of combustion to other fire areas. It is important that means be provided to ventilate, exhaust, or isolate the fire area as required and that consideration be given to the consequences of ventilation system failure caused by the fire, resulting in a loss of control for ventilating, exhausting, or isolating a given fire area. Special protection for ventilation power and control cables may be necessary. The power supply and controls for mechanical ventilation systems should be run outside the fire area served by the system where practical. Release of smoke and gases containing radioactive materials to the environment should be monitored in accordance with emergency plans as described in RG 1.101, “Emergency Planning and Preparedness for Nuclear Power Reactors” (Ref. 101). Any ventilation system designed to exhaust potentially radioactive smoke or gases should be evaluated to ensure that inadvertent operation or single failures will not violate the radiologically controlled areas of the plant design. This should include containment functions for protecting the public and maintaining habitability for 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