East Coast Earthquake and North Anna
11:30 am, August 24, 2011
As indicated below, power has been restored to North Anna and emergency diesel generators are no longer being used. Both reactors at North Anna remain shutdown. One of the diesel generators suffered a coolant leak, which is why it failed. It’s not yet clear whether the leak was caused by the earthquake or was a result of earlier improper maintenance and inspection. The reactors will remain shutdown for inspection for possible earthquake-related damage; at this writing there is no indication how long that might be.
Most importantly is that, according to Dominion Resources, North Anna is designed to withstand only a 6.2 earthquake. At a U.S. Geological Survey rating of 5.8, the east coast earthquake came uncomfortably close to the margin. A 2008 NRC survey of earthquake risk at U.S. reactor sites placed North Anna as the seventh riskiest site in the country–based on possible earthquake size and reactor design basis. The riskiest site according to the NRC? Indian Point, NY, just 35 miles from Manhattan. Here is a March 2011 report from MSNBC on earthquake risk and nuclear power in the U.S.
Clearly there is a pressing need to upgrade existing reactor sites to withstand larger earthquakes than now contemplated–or close them. This is as true for the east coast and midwest as it is for the much more earthquake-prone California reactors at San Onofre and Diablo Canyon–which could experience far, far stronger earthquakes than that felt in the east yesterday.
5:00 pm, August 23, 2011
Platt’s is reporting that PJM, which runs the electrical grid in the Mid-Atlantic, says that offsite power has been restored to North Anna.
4:30 pm, August 23, 2011
A 5.8 magnitude earthquake struck the east coast of the United States about 1:45 pm on August 23, 2011. The epicenter was just a few miles from the two-reactor North Anna nuclear power station, operated by Dominion Resources.
The two reactors at North Anna lost offsite power and automatically scrammed. Emergency diesel generators came on as designed, however the Washington Post reports that one of the site’s four generators failed.
It is not clear why or how North Anna lost power. NIRS was contacted by individuals living nearby the reactor site who said they still had power. A Nuclear Regulatory Commission spokesperson was unable to tell NIRS why or how North Anna lost power, nor how long the power outage might be. Dominion says it has enough fuel onsite to operate the generators for three days–assuming the remaining generators operate properly of course.
The NRC says several other sites declared “Unusual Events,” the lowest of the NRC’s four-level emergency classification system. These include: Peach Bottom, Three Mile Island, Susquehanna and Limerick in Pennsylvania; Salem, Hope Creek and Oyster Creek in New Jersey, Calvert Cliffs in Maryland, Surry in Virginia, Shearon Harris in North Carolina and D.C. Cook and Palisades in Michigan.
Only North Anna shut down as a result of the quake.
According to Robert Alvarez of the Institute for Policy Studies:
“The North Anna reactors are of the Westinghouse Pressurized Water design and went on line in 1979 and 1980 respectively. Since then the reactors have generated approximately 1,200 metric tons of nuclear spent fuel containing about 228,000 curies of highly radioactive materials — among the largest concentrations of radioactivity in the United States.
“Nearly 40 percent of the radioactivity in the North Anna spent fuel pools is cesium-137 – a long-lived radioisotope that gives off potentially dangerous penetrating radiation and also accumulates in food over a period of centuries. The North Anna Pools hold about 15-30 times more Cs-137 than was released by the Chernobyl accident in 1986. In 2003, IPS helped lead a study warning that drainage of a pool might cause a catastrophic radiation fire, which could render an area uninhabitable greater than that created by the Chernobyl accident.
“The spent fuel pools at North Anna contain 4-5 times more than their original designs intended. As in Japan, all U.S. power nuclear power plant spent fuel pools do not have steel lined, concrete barriers that cover reactor vessels to prevent the escape of radioactivity. They are not required to have back-up generators to keep used fuel rods cool, if offsite power is lost. Even though they contain these very large amount of radioactivity, spent reactor fuel pools in the U.S. are mostly contained in ordinary industrial structures designed to protect them against the elements.”