US Dept. of Energy |
Office of International
Nuclear Safety and Cooperation
1000 Independence Ave S.W.
Washington, DC 20585
Nuclear power plants must be able to shut down safely in the
event of fire. Current U.S. fire safety procedures for nuclear plants are
the result of a 1975 fire at the Tennessee Valley Authority's Browns Ferry
plant. The U.S. experience since 1975 has provided important insights to
help improve fire safety at Soviet-designed nuclear power plants.
International standards call for redundant
safety systems so that if a fire or explosion damages key equipment in one
area of a plant, similar equipment in another area can be used to shut
down safely and prevent core damage. Older models of RBMK and VVER plants
either are not equipped with these redundant safety systems or do not
provide adequate barriers between the systems. As a result, damage caused
by fire in a single zone could lead to severe core damage and the release
of radioactive materials.
In cooperation with Ukraine and Russia, the
U.S. Department of Energy has developed the Reactor Core Protection
Evaluation Methodology for Fires at Soviet-Designed Nuclear Power Plants.
The guidelines enable analysts to assess fire hazards and identify
cost-effective changes in procedures and equipment, including the
development of redundant safety systems. Pilot studies are underway at the Smolensk nuclear power plant in Russia and at the Zaporizhzhya nuclear power plant in Ukraine.
As part of the
studies, staff at the nuclear plants are working to:
- establish safe
shutdown performance goals
- collect data
- review original designs
and as-built plant drawings
- validate design information by physical
observation of plant conditions
- assess fire potential and fire effects
- analyze equipment performance and personnel capabilities
- evaluate safe shutdown capabilities in the event of fire in various
areas of a plant.
As part of the pilot studies, recommended
changes will be prioritized, so the most cost-effective measures can be
implemented first. Implementing these recommended changes should reduce
the risk of a large radioactive release in the event of a fire.
Development of the guidelines was supported by the U.S. Nuclear Regulatory
Commission and the U.S. commercial nuclear industry, with substantial
input from international experts in the United Kingdom, Austria, Sweden,
Finland, Germany, Belgium, Norway, and Italy. In addition to the studies,
fire protection equipment and technology are being provided to help ensure
safe shutdowns in fire emergencies. These include fire doors, penetration sealant and fire
resistant cable coating, sprinkler systems, fire detection and alarm systems, fire resistant floor coating material, and structural steel coating material.