Nuclear safety and security called a nuclear meltdown. After shutting down, for some time the reactor still needs external energy to power its cooling systems. Normally this energy is provided by the power grid to which that plant is connected, or by emergency diesel generators. Failure to provide power for the cooling systems, as happened in Fukushima I, can cause serious accidents. Nuclear safety rules in the United States "do not adequately weigh the risk of a single event that would knock out electricity from the grid and from emergency generators, as a quake and tsunami recently did in Japan", Nuclear Regulatory Commission officials
Nuclear power in the United States undermined confidence in nuclear safety. All of these well-publicised events, undermined public support for the U.S. nuclear industry in the 1970s and the 1980s. On March 5, 2002, maintenance workers discovered that corrosion had eaten a football-sized hole into the reactor vessel head of the Davis-Besse plant. Although the corrosion did not lead to an accident, this was considered to be a serious nuclear safety incident. The Nuclear Regulatory Commission kept Davis-Besse shut down until March 2004, so that FirstEnergy was able to perform all the necessary maintenance for safe operations. The NRC imposed its largest fine ever—more than $5