"ROCKVILLE, Md. — Nuclear safety rules in the United States do not adequately weigh the risk that a single event would knock out electricity from both the grid and from emergency generators, as an earthquake and tsunami recently did at a nuclear plant in Japan, officials of the Nuclear Regulatory Commission said Wednesday.
A task force created after the accident at the nuclear plant, Fukushima Daiichi, delivered an oral progress report on Wednesday to the five-member commission. In that session, commission officials said they had learned that some of the safety equipment installed at American nuclear plants over the years, including hardware added after the Sept. 11, 2001, terrorist attacks, is not maintained or inspected as diligently as the original components are.
A crucial reason for the extensive damage to the Fukushima plant’s reactors was the loss of electricity needed to run water pumps and to reposition valves. The American nuclear industry has argued in recent months that its reactors are better prepared to cope with that kind of emergency.
But Charlie Miller, the chairman of the task force, said that studies by safety experts in the United States had analyzed the risk of losing electricity from the grid or from on-site emergency generators, but not both at the same time."