Fire Protection for Operating Nuclear Power Plants and Decommissioning Reactors (NUREG/BR-0522, Revision 1)

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Publication Information

Date Published: December 2022

Office of Nuclear Reactor Regulation 
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001


Fires are a potential hazard at most large industrial facilities, including nuclear power plants. Fires are expected to occur over the plant’s life and are treated as operational events rather than as design-basis accidents.

Flammable materials at nuclear power plants differ from those at conventional power generation facilities, fossil-fuel power plants (coal steam, oil or gas steam, combined cycles, and gas-fired simple-cycle combustion turbines), and many other industrial plants. A nuclear power plant does not have a constant flow of fuel (e.g., coal or oil) as the hazard. However, it may have similar fire hazards, such as grouped electrical cables and lubricating products.

The U.S. Nuclear Regulatory Commission (NRC) requires all operating commercial nuclear power plants and decommissioning power reactors to have a fire protection program. The goal for operating reactors is to minimize fire damage to structures, systems, and components important to safety and prevent a fire from causing a radiological release that adversely affects the public, environment, or plant personnel. This is to ensure the ability to safely shut down the reactor and to ensure it can maintain a safely shutdown condition. An operating reactor’s fire protection program helps establish the basis for a similar program for the decommissioning phase. Its goal is to provide an appropriate level of defense-in-depth protection against the threat of fires.

The primary objectives of fire protection programs at U.S. operating commercial nuclear power plants are to minimize the probability of occurrence and the consequences of fire. Meeting these objectives through compliance with NRC fire protection regulations provides reasonable assurance, that a fire will not prevent the necessary safe-shutdown functions from being performed, and that radioactive releases to the environment in the event of a fire will be minimized. Defense-in-depth for fire protection involves a comprehensive program of administrative controls and physical fire protection features that ensure the protection of structures, systems, and components necessary to prevent or mitigate release of radioactive materials. This combination of elements reduces both the probability and consequences of fire events, and it ensures that if one fire protection element fails, other parts of the fire protection program will adequately compensate, thereby minimizing the risks to the public, environment, and plant personnel.

Title 10 of the Code of Federal Regulations (10 CFR) 50.48, “Fire protection,” establishes detailed requirements for fire protection programs at commercial nuclear power plants. These programs include measures related to fire prevention, automatic detection, suppression, and response, as well as personnel administrative requirements and the protection of safety--related structures, systems, and components in the event of a fire. The regulation in 10 CFR 50.48(a) requires each operating nuclear power plant to have a fire protection plan that satisfies General Design Criterion 3, “Fire protection,” of Appendix A, “General Design Criteria for Nuclear Power Plants,” to 10 CFR Part 50, “Domestic licensing of production and utilization facilities.” Under 10 CFR 50.48(f), a nuclear power plant licensee that has certified the permanent cessation of operations and the removal of fuel from the reactor vessel under 10 CFR 50.82(a)(1) must maintain a fire protection program to address the potential for fires that could cause the release or spread of radioactive materials (i.e., result in a radiological hazard).

Page Last Reviewed/Updated Monday, December 19, 2022