nuclear-news

New costly earthquake security could close some US nuclear plants

New Quake Risks Seen for Nuclear Plants WSJ, By REBECCA SMITH, JANUARY 31, 2012,   Nuclear reactors in the central and eastern U.S. face previously unrecognized threats from big earthquakes, the Nuclear Regulatory Commission said Tuesday. Experts said upgrading the plants to withstand more substantial earth movements would be costly and could
force some to close.

The NRC said it would require nuclear-plant operators to conduct new
seismic studies for all 96 reactors east of the Mississippi River to
determine if the plants could withstand the shaking predicted by the
government’s new seismic model…..
The NRC plans to give nuclear-plant operators four years to
re-evaluate risks at their operations by running complex calculations
for all structures, systems and components. By law, nuclear plants
must be able to withstand earthquakes “without functional impairment
of those features necessary to shut down the reactor, maintain the
station in safe condition and prevent undue risk to the health and
safety of the public.”
Critics said regulators are moving too slowly. “The NRC does not need
a new model—it needs a spine,” said Dave Lochbaum, director of nuclear
safety for the Union of Concerned Scientists in Chattanooga, Tenn. The
NRC already has sufficient evidence to require immediate upgrades to
dozens of plants, he said, adding that further delay amounts to a
“bureaucratic stall tactic.”….
The model shows increased hazards at many locations. For example, it
indicates that the single worst earthquake likely to happen in a
10,000-year period in Chattanooga, Tenn., would be nearly twice as
damaging to structures as previously calculated. Scientists found
similar hazards at six other locations where they did spot checks:
Houston; Manchester, N.H.; Jackson, Miss.; Topeka, Kan.; central
Illinois; and Savannah, Ga…..
Because regulators worry about “low probability/high consequence”
events like the one in Japan, much seismic research now is focused on
the central and eastern U.S., an area once seen as less active
geologically than the West. There are 96 reactors in the region,
compared with just eight in the West.

Scientists, using computers, satellites and field data, now know there
have been many huge earthquakes in the past in the central and eastern
regions of the country. And shock waves travel far in the East because
the Earth’s crust is more rigid than in the West.
http://online.wsj.com/article/SB10001424052970203920204577195121591806242.html

February 1, 2012 - Posted by Christina Macpherson | safety, USA