Radioactive leak closes Sellafield

A highly radioactive leak has forced the closure of Sellafield's £2.1 billion reprocessing plant.

The dangerous mixture, containing about 20 tonnes of uranium and plutonium, leaked through a pipe into a huge stainless steel chamber at the Thorp plant.

The leak - enough to half fill an Olympic-size swimming pool - is so radioactive it is impossible to enter and will take several months to mop up. Special robots may have to be built to help out.

The alarm was raised on 19 April when operators could not account for all the spent fuel that had been dissolved in nitric acid. It was travelling through the plant to be separated into uranium, plutonium and waste products. Most of the material is uranium but the fuel contains 200kg of plutonium, enough to make 20 nuclear weapons.

The leak is not considered a danger to the public but the taxpayer now faces the financial implications of the shutdown - income from the Thorp plant pays for the clean-up of redundant nuclear facilities. The Nuclear Decommissioning Authoritya quango which took over ownership of the plant from British Nuclear Fuels on 1 April, has a £2.2billion clean-up budget this year, of which £560million was to come from the Thorp operation.

Richard Flynn, NDA spokesman, said: "If the income from the plant is not forthcoming then obviously it will put back plans for cleaning up."

British Nuclear Group managing director, Barry Snelson, said: "The plant is in a safe and stable state. Safety monitoring has confirmed no abnormal activity in the air and there has been no impact on the workforce or the environment."