A story in today's Wall Street Journal by the paper's ace energy reporter Rebecca Smith describes an order just issued by the U.S. Nuclear Regulatory Commission requiring operators of all 96 reactors located in the eastern United States to reevaluate them in terms of revised earthquake risk estimates. Given added urgency by the nuclear catastrophe at Fukushima, where reactors were found to have been not designed for an earthquake of the severity that hit them, the NRC is telling owners of nuclear power plants that they must review them in light of a new seismic risk model jointly developed by the NRC, the Department of Energy and the Electric Power Research Institute (EPRI).
The process of developing that model preceded Fukushima, a point Smith neglects to make. But the model's damage risk estimates are often significantly higher than those considered authoritative when existing nuclear power plants were designed and built. The model suggests, for example, that the worst earthquake expected in Chattanooga, Tennessee, in a 10,000 year period might be twice as damaging to structures as previously expected. The Sequoyah plant, is located 18 miles north of Chattanooga.