Hurricane Sandy devastated homes, but did not damage nuclear power plants in its path. Photo: Courtesy of FEMA
Whenever
severe weather events occur – such as last week’s Hurricane Sandy – it
always prompts questions about how nuclear power plants are prepared to
handle them.
The
answer is always the same: Every U.S. nuclear plant has a list of
severe weather conditions that require it to shut down as a precaution.
But because these plants are built robustly, and built to withstand the
expected forces of nature in the area, they don’t necessarily have to
shut down in the face of severe weather. It all depends on their
specific criteria.
For
example, forecasts of hurricane-force winds within 24 hours or expected
storm surges greater than a given height may trigger a plant’s shutdown
criteria and allow them time to get backup systems ready. But even if
an area experiences strong or damaging storm conditions, a plant in that
area may be designed to continue operating to help the electric grid
power essential services such as hospitals and police and fire stations.
However, plants would shut down or reduce power if the electric grid
was damaged.
In
addition to protections again wind, every U.S. nuclear plant is
designed to withstand severe flooding (and storm surge for coastal
plants), and key components and systems are protected by watertight
buildings capable of withstanding major hurricane-force winds and
flooding.
Sandy is just the latest storm to pass near nuclear plants without significant impact. For example:
• In 2005, the
Waterford 3
plant in Louisiana remained safe after Hurricane Katrina knocked out
the plant’s connection to the electric grid. Waterford ran its safety
equipment on emergency diesel generators and remained safe once it
reconnected to the grid four days later.
• In 2004, both reactors at the
St. Lucie site
in Florida remained safe after Hurricane Jeanne knocked out the plant’s
grid connection. The plant’s staff manually shut down the reactors
properly and all emergency equipment, including the diesel generators,
ran as expected to keep the plant safe.
• In 1992, both reactors at the
Turkey Point site
in south Florida remained safe after Hurricane Andrew, one of the most
powerful hurricanes to hit the United States, passed directly over the
plant and knocked out the area’s electrical infrastructure. Turkey
Point’s emergency diesel generators ran for six days.
NRC
regulations ensure that nuclear power plants can remain safe even
during a hurricane and loss of outside power to run safety systems. The
sites keep about a week’s worth of diesel onsite for the emergency
generators, and the utilities typically have agreements in place that
give them priority in getting more diesel to the sites if necessary. The
diesel generators sit in buildings designed to safely withstand just as
much punishment as the reactor safety systems.
These
regulations were enhanced after 9/11, when the NRC required U.S. plants
to put in place additional portable generators and pumps. During Sandy,
the
Oyster Creek plant
had those additional resources available but ended up not needing them.
In the wake of Fukushima, the NRC has ordered the plants to obtain even
more portable equipment and make sure it’s protected from severe
weather and other events.
All
of this effort helps ensure that the public remains safe even if a
hurricane, nor’easter or blizzard affects a nuclear power plant near
you.
Scott Burnell
Public Affairs Officer
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