Compensatory and Alternative Regulatory MEasures for Nuclear Power Plant FIRE Protection (CARMEN-FIRE) (NUREG/CR-7135, BNL-NUREG-104309-2014)

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Publication Information

Manuscript Completed: June 2015
Date Published:
August 2015

Prepared by:
K. Sullivan
Brookhaven National Laboratory
Nuclear Science and Technology Department
P.O. Box 5000
Upton, NY 11973

F. Gonzalez, NRC Project Manager

Prepared for:
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

NRC Job N6760

Availability Notice


Each commercial nuclear power plant (NPP) operating in the United States has a comprehensive Fire Protection Program (FPP) that the U.S. Nuclear Regulatory Commission (NRC) has reviewed and approved.1 The purpose of the FPP is to prevent the occurrence of fire, and minimize radioactive releases to the environment in the unlikely event that a significant fire was to occur. To achieve these objectives, the FPP integrates plant design and operating features (i.e., structures, systems, components, personnel- and administrative-controls) that assure defense-in-depth protection of the public's health and safety. This means that the FPP includes measures directed at reducing the likelihood of fires and explosions, rapidly detecting and suppressing those fires that do occur, and ensuring the capability to achieve and maintain safe shutdown conditions should there be a serious fire.

Over the lifetime of a plant, certain elements of the FPP may be found to be in a degraded or otherwise nonconforming condition (i.e., impaired). To maintain conformance to the defense-in-depth safety concept, an adequate level of fire safety must be maintained whenever a fire protection feature is disabled or impaired. Hence, a key element of the approved FPP is ensuring that appropriate actions are taken promptly to mitigate the effects of such impairments until permanent corrective actions can be completed. The objective of these interim fire-safety enhancements, called "compensatory measures," is to provide reasonable assurance that any degradation in fire safety caused by an impairment will be appropriately compensated until permanent corrective actions are completed.

Employing compensatory measures, on a short-term basis, is an integral part of NRC-approved fire protection programs. For most generic impairments, such as a blocked sprinkler head or a damaged fire hose station, the appropriate measures will be specified in the approved FPP. In certain unique, plant-specific cases, however, the measures specified in the FPP may not assure an appropriate level of fire safety. When such unique circumstances are encountered, it is expected that an appropriate alternate measure would be implemented. Depending on the plant-specific circumstances, alternate compensatory measures may be fairly straightforward, such as a procedural enhancement, or more complex, such as installing one or more of the technologically advanced fire protection features described in Appendix B of this report.

This report is intended to serve an information resource related to interim compensatory measures. This report documents the history of compensatory measures, and details the NRC's regulatory framework established to ensure they are appropriately implemented and maintained. This report also explores technologies that did not exist when the current plants were licensed, such as video-based detection systems, temporary penetration seals, and portable suppression systems that, under certain conditions, may offer an effective alternative to the measures specified in a plant's approved fire protection program.

1 As defined by the NRC in 10 CFR 50.48 and the Generic Letter 81–12, an approved Fire Protection Program includes the fire protection and post-fire safe shutdown systems necessary to satisfy the NRC's guidelines and requirements; administrative and technical controls; the fire brigade and the fire protectionrelated technical staff; and other related plant features which have been described by the licensee in the FSAR, fire hazards analysis, responses to staff requests for additional information, comparisons of plant designs to applicable NRC fire protection guidelines and requirements, and descriptions of the methodology for assuring safe plant shutdown following a fire.

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