Nuclear regulators already have “sufficient information and knowledge” to deal with earthquake risks at existing U.S. reactors and don’t need to wait for a broader review, a safety advocate said.
The Nuclear Regulatory Commission developed seismic rules for new plants in 1996 and has since approved preliminary construction for proposed nuclear units at a Southern Co. plant in Georgia and certified an early reactor design by Toshiba Corp.’s Westinghouse Electric unit, according to comments filed with the agency today by David Lochbaum, director of the Nuclear Safety Project at the Cambridge, Massachusetts-based Union of Concerned Scientists.
“If the NRC truly lacks sufficient information about seismic hazards and how safety at nuclear power reactors is affected, then the agency cannot responsibly have issued early site permits and certified new reactor designs,” he said.
The NRC is in the process of evaluating seismic hazards in the central and eastern U.S. in response to updated geologic information. By the end of this year, the agency plans to develop an earthquake probability model for reactor owners to use and may require all U.S. plants to review their seismic risks within the next two years.
The NRC has said “repeatedly” the broad seismic review “deals with an issue that fails to present an immediate safety concern,” Scott Burnell, an agency spokesman, said in an e-mail. Existing plants are built to “safely withstand the earthquakes at their sites,” he said.
The NRC is weighing requirements to bolster plant protections against earthquakes and floods in the wake of the nuclear disaster in Japan caused by a March temblor and tsunami that led to radiation leaks and meltdowns at Tokyo Electric Power Co.’s Fukushima Dai-Ichi plant.
An 5.8-magnitude earthquake in Virginia on Aug. 23 shut down reactors at Dominion Resources Inc.’s North Anna nuclear plant, about 11 miles (18 kilometers) from the epicenter.
The Virginia earthquake caused no significant damage at North Anna, even though ground shaking exceeded the plant’s design limits, Dominion has said.
“The recent experience at North Anna supports the agency’s conclusion” that existing plants are built to withstand earthquakes at their sites, Burnell said.