It is unlikely to be used again. Since 1945 there have been 60 known accidents at nuclear reactors and processing plants. Thirty-three have occurred in the United States and 19 in the former Soviet Union. If the major accidents in nuclear history have told us anything, it is that the potential for operator error must, as far as possible, be designed out of the system. The behaviour of nuclear material is well understood.
Accidents usually occur when the rules are broken.
Chernobyl The 1986 Chernobyl accident was the supreme example of human incompetence on many levels. The power station's operators wanted to test the efficiency of its electricity generators after the supply of steam coming off their RBMK nuclear reactor had been switched off. They knew this was dangerous, but pressed ahead even when a problem started to develop in the reactor's core. Left to itself, the Chernobyl reactor should have shut itself down automatically. But the operators overrode the safety systems.