The North Anna nuclear plant was found to have only minor damage from August's… (Scott Olson, Getty Images )
Reporting from Washington — The Nuclear Regulatory Commission has determined that the Aug. 23 East Coast earthquake caused only minor damage to the North Anna nuclear power plant, but federal regulators declined to say when the facility could restart operations.
At a crowded public hearing Monday at the power station, 12 miles from the quake epicenter near Mineral, Va., officials said a monthlong investigation indicated that the temblor shook the ground more than the nuclear facility was designed to withstand.
As a result, some outside experts argue that the regulatory commission should reexamine reactor designs and safety precautions at nuclear plants in active seismic zones across the country.
The hearing marked the end of the commission's inquiry into what happened during the quake, and how the plant's operator responded. A new inspection team is scheduled to arrive Wednesday to determine what repairs or modifications are required to ensure the facility can restart safely.
David Heacock, president of Dominion Virginia Power, which operates North Anna, said the plant would not restart operations "until we are convinced North Anna can operate as safely as it has" and federal regulators gave their approval.
The station's two nuclear reactors, which generate a total of 1,800 megawatts of electricity, have been offline since the magnitude 5.8 earthquake.
Gregory Kolcum, the commission's senior resident inspector at North Anna, was in the control room when the shaking started. He said Dominion staff acted "in accordance with approved procedures and in a manner that maintained public health and safety."
Inspectors found several problems at the plant, however.
They said an alarm panel for seismic activity lost power because of the quake, indicating a need for a backup power supply. Additionally, seismic monitors used to measure ground motion were inside the building, rather than in the ground. That could give an inaccurate reading of how much shaking occurred.
Kolcum said the agency would review the problems to see whether modifications were needed at other nuclear power plants.
Nearby residents who attended the meeting expressed concern that only one of the two reactors had undergone a complete inspection of its nuclear core.
Dominion inspectors said they found no significant damage during a detailed review of the Unit 2 reactor. Federal regulators have not required the company to do a similar multi-day inspection of the Unit 1 reactor.
"The NRC has no plans to require an inspection of Unit 1 prior to the restart," said Victor McCree, regional administrator for the commission. "At this point, we do not see the need."