“Reactors in central, eastern U.S. face greater earthquake threat, study finds.
The Wall Street Journal reports,
Nuclear reactors in the central and eastern U.S. face previously unrecognized threats from big earthquakes, the Nuclear Regulatory Commission said Tuesday. Experts said upgrading the plants to withstand more substantial earth movements would be costly and could force some to close.
The NRC said it would require nuclear-plant operators to conduct new seismic studies for all 96 reactors in eastern and central states to determine if the plants could withstand the shaking predicted by the government’s new seismic model.
Updating the U.S. survey of past seismic activity became urgent after a 9.0-magnitude earthquake and tsunami devastated northeastern Japan last March. The event overwhelmed the defenses of reactors at the Fukushima Daiichi site, causing widespread damage and radioactive releases. The earthquake exceeded the level for which the reactors had been designed, calling into question earlier seismic assessments.
The NRC plans to give nuclear-plant operators four years to re-evaluate risks by running complex calculations for all structures, systems and components. By law, nuclear plants must be able to withstand earthquakes “without functional impairment of those features necessary to shut down the reactor, maintain the station in safe condition and prevent undue risk to the health and safety of the public.”
The seismic study “is an important piece of work but it doesn’t tell us what needs to be done,” said Alex Marion, vice president for nuclear operations at the Nuclear Energy Institute, a trade organization. “The model will need to be applied to specific sites and that will take awhile.”
Critics said regulators are moving too slowly. “The NRC does not need a new model—it needs a spine,” said Dave Lochbaum, director of nuclear safety for the Union of Concerned Scientists in Chattanooga, Tenn. The NRC already has sufficient evidence to require immediate upgrades to dozens of plants, he said, adding that further delay amounts to a “bureaucratic stall tactic”…
The problem with Fukushima, however, wasn’t the earthquake so much as it was the ensuing tsunami. There won’t be many tsunamis in the central U.S.
As to the eastern U.S. plants, ensuring the generators are above tsunami level (i.e., put them on concrete pedestals) would likely go a long way to avoiding a Fukushima-type disaster.