History of leaks, blasts and secrecy

The history of civil nuclear energy has been dogged by explosions, radiation leaks and the occasional cover-up.
The events at Chernobyl, Windscale and Three Mile Island provide reminders of the devastating effects of nuclear accidents.
The site of the world´s worst nuclear disaster was the Chernobyl plant in Ukraine, then part of the Soviet Union.
In April 1986, one of four reactors overheated and caused a huge explosion, spreading radioactive waste across Europe. The World Health Organisation said that although only two workers died in the initial explosion, it estimated in 2006 that about 9,000 deaths had been directly linked to the radioactivity.
Britain's worst nuclear accident ocurred in 1957 when a fire broke out at the Windscale (now Sellafield) reactor in Cumbria. The fire was put out before it sparkled an explosion, but about 200 people in Britain developed cancers, half of which proved fatal.
In 1979 the Three Mile Island plant in Pennsylvania overheated when a small valve designed to relieve pressure in the reactor malfunctioned. The core temperature of the plant soared and workers narrowly saved it from meltdown.
Until last week's earthquake, Japan had had four serious radiation leaks or explosions at its nuclear power stations since 1981.
In 1999 operators who were not trained in handling uranium overloaded the tank ata a reactor outside Tokyo. The resulting explosion killed two workers and put 100 others - who were exposed to radiation - in hospital.
The Sunday Times, March 13, 2011