Nuclear safety in the United States inadvertently reversed pipe restraints at the Diablo Canyon Power Plant reactors, compromising seismic protection systems, which further 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. In 2002, the USA had what former NRC Commissioner Victor Gilinsky termed "its closest brush with disaster" since Three Mile Island's 1979 meltdown; a workman at the Davis-Besse reactor found a large rust hole in the top of the reactor pressure vessel. Recent concerns have been expressed about safety issues affecting a large part of the nuclear fleet of
Corium (nuclear reactor) ejected as a molten stream by the pressure inside the reactor vessel. The reactor vessel failure may be caused by heating of its vessel bottom by the corium melt, resulting first in creep failure and then in breach of the vessel. Cooling water from above the corium layer, in sufficient quantity, may obtain a thermal equilibrium below the metal creep temperature, without reactor vessel failure. If the vessel is sufficiently cooled, a crust between the melt and the reactor wall can form. The layer of molten steel at the top of the oxide may create a zone of increased heat