The August 23 earthquake that shook the East Coast is raising concerns over the safety of U.S. nuclear power plants. Concerns are heightened in light of the ongoing nuclear crisis at the Fukushima Daiichi nuclear plant in Japan after an earthquake struck in March.
A 5.8 magnitude earthquake hit outside Richmond, Va., about 20 miles from Dominion Energy’s 1,800 MW North Anna nuclear power plant. The two Westinghouse three-loop pressurized water reactors shut down automatically as they were designed to do and four diesel generators were activated to keep the reactors’ radioactive cores cool. One diesel generator developed a coolant leak and was shut down, according to the event notification on the U.S. Nuclear Regulatory Commission (NRC)’s Web site. A fifth diesel generator was activated to replace it until off-site power was restored. Reuters quoted Dominion spokesman Jim Norvelle as saying that the plant was designed to withstand an earthquake of up to 6.2 in magnitude.
Dominion said off-site power was restored on August 24 and the utility ended the alert at the plant on the same day. No earthquake-related damage was reported and the generator that shut down has been repaired.
The NRC said it is assessing North Anna’s normal operating systems and structures and resident inspectors continue to observe the plant’s activities and provide information to the commission. The NRC said it will determine if any follow up inspections are needed to determine whether the plant withstood the quake as designed.
Nuclear power plant safety concerns have been prominent since a 9.0 magnitude earthquake and tsunami hit the Fukushima Daiichi nuclear power plant in Japan in March. The disasters shut down generators leading to meltdowns at three of the plant’s reactors and the release of radiation into the air.
In April, the NRC formed the Near-Term Task Force to study what can be learned from the disaster at Fukushima. The report concluded a similar chain of events was “unlikely” to happen in the U.S., but proposed 12 safety recommendations covering areas including loss of electrical power, earthquakes, flooding spent fuel pools and preparedness. The NRC told its staff it had until October 3 to determine which of the task force’s recommendations to implement first.
Massachusetts Rep. Edward Markey said in an August 24 letter to NRC Chairman Gregory Jaczko that the Virginia earthquake is a sign the Task Force recommendations need to be implemented sooner rather than later.
“The Virginia earthquake is now our local 911 call to stop delaying the implementation of stricter safety standards,” Markey said.
Markey also said the diesel generator failure at North Anna “illustrates a long-standing concern related to the adequacy of maintenance of emergency diesel generators that must be addressed in order to be certain that any loss of external electricity – be it caused by an earthquake, tornado, flood or terrorist attack – does not lead to the same sort of catastrophic meltdowns that occurred in Japan.”
Markey said that having emergency diesel generators and secondary battery generators onsite “is not sufficient.” He called on the NRC to prescribe and enforce maintenance requirements to ensure that the generators operate as intended.
A report that Markey released in May found 74 reports of emergency diesel generator inoperability at 33 nuclear plants in the past eight years, including the one at North Anna, despite warnings from the NRC in 1989 and 2007.
Tony Pietrangelo, senior vice president and chief nuclear officer with the Nuclear Energy Institute, said every nuclear plant affected by the earthquake performed as it was supposed to.
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