By BRYAN RAHIJA
Bob Alvarez, a Senior Scholar at the Institute for Policy Studies (IPS) who with support from POGO authored a recent report on the dangers associated with how the majority of nuclear spent fuel is stored in the U.S., just sent the following in an email regarding this afternoon's earthquake felt across the East Coast:
An earthquake measuring 5.9 on the Richter scale just occurred less than a hour ago. It's epicenter was in Mineral, VA—approximately 10 miles from two nuclear power reactors at the North Anna site. According to a representative of Dominion Power, the two reactors were designed to withstand a 5.9-6.1 quake. The Nuclear Regulatory Commission (NRC) ranked the North Anna Reactors as being 7th in the nation in terms of earthquake risks.
Control rods are automatically inserted to halt a reactor, if it is impacted by an earthquake. However, the reactor core still has a large amount of decay heat that requires power to remove it if there is a loss of offsite power to prevent a melt down. It is reported that the North Anna reactors were shut down and is operating with back-up diesel generators. The failure to remove reactor decay heat is what led to severe accidents at the Fukusima nuclear site on Japan. It is not clear, at this time, what damage might have been sustained at the nuclear site.
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.
Update: Bloomberg reports that the North Anna power plant has lost power.
Dominion Resources Inc. lost all offsite power at its North Anna nuclear power plant in Virginia and began using backup diesel generators after a 5.9-magnitude earthquake struck nearby.
One of the four diesel generators stopped working after startup, David McIntyre, a spokesman for the U.S. Nuclear Regulatory Commission, said in an e-mail today. There were no reports of damage at the plant, he said.
Bryan Rahija edits POGO's blog.