A Dominion Resources Inc. nuclear power plant in Virginia may have been subjected to ground motion greater than it was designed to withstand in last week’s earthquake, the Nuclear Regulatory Commission said.
Dominion notified the agency that a review determined shaking from the 5.8-magnitude temblor “may have exceeded” design limits of the North Anna Power Station, the agency said today in an e-mailed statement. The NRC sent additional inspectors to the plant to assist agency officials in their investigation, the agency said.
The North Anna plant, about 40 miles (64 kilometers) northwest of Dominion’s Richmond headquarters, has been shut since the Aug. 23 earthquake. Dominion is gathering data on the event and its effect on the plant, Jim Norvelle, a Dominion spokesman, said today in an e-mail.
“Dominion needs to do more analysis to determine how a quake of that strength could affect the plant’s ability to safely shut down,” Scott Burnell, an NRC spokesman, said in an e-mail.
Dominion is analyzing data and reports may not be completed until the end of the week, Norvelle said.
“In multiple inspections, we have not found significant damage,” he said. Some insulation was shaken from pipes during the earthquake, according to Norvelle. “All safety systems operated as designed and built,” he said.
Seismic, Structural Experts
The nuclear agency said a seismic expert and a structural engineer were sent to the plant after the earthquake. Technical experts will join agency officials at the plant to help the NRC collect information on the effect at North Anna and to help assess earthquake risks at U.S. nuclear reactors.
The addition of NRC experts “should not be interpreted to mean that Dominion staff responded inappropriately or that the station is less safe as a result of the quake,” said Victor McCree, the agency’s regional administrator, said in the statement.
Dominion isn’t disclosing when the plant may start generating electricity because such market-sensitive information may affect electricity prices, Norvelle said.