Daniel Frumkin
Senior Fire Protection Engineer
The NRC’s fire protection staff and graphic artists have worked together to create a new
introduction
to our website’s fire protection pages. The illustrations for the
“Prevention,” “Suppression” and “Safe Shutdown” tabs highlight the
details in each area of fire protection.
Prevention
is a combination of training, NRC inspections and procedures to keep
potential fire starters such as welding under control. U.S. reactors
have improved their prevention efforts over time. In 1985 they reported
22 significant fires. By the late 1990s, even though more reactors were
running, the annual reporting numbers had fallen by more than half. In
2011 U.S. plants reported only six significant fires – less than one
fire for every 10 operating reactors.
The
next layer of protection involves fighting fires if they occur at or
near a reactor. Plants’ fire detection systems are a lot like the smoke
detectors in your house. When these detectors go off, however, trained
firefighters show up with extinguishers and fire hoses. Many key plant
areas also have automatic sprinkler systems. Plants also have plenty of
firefighting water available and can get that water onto a fire using
onsite staff and equipment or fire engines from nearby communities.
Even
with all these measures, U.S. plants must still be able to safely shut
down if a fire breaks out. The fire protection approach puts barriers
between each reactor’s multiple sets of shutdown equipment, so a fire
can’t disable all the equipment at once. The power and control cables
are separated to make sure that those systems are available to shut the
plant down.
Plants
also have alternate control stations if fires disrupt the control
room’s ability to manage the situation. The plants have emergency power
sources, both installed large diesel generators and portable equipment
the NRC required after 9/11. These sources help ensure fires outside the
reactor can’t deprive systems of the electricity they need.
Check out the new graphics and fire protection
web pages.
We hope this information makes the topic easier to understand and gives
you a better sense of how layers of protection help ensure nuclear
plants remain safe from fires.
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