The operators of the Sellafield Nuclear Reprocessing Plant have been fined £500,000 following failures which led to a leakage of highly radioactive liquid within the plant.
British Nuclear Group, which operates Sellafield, had pleaded guilty to three breaches of their operating licence following prosecution by Britain's Health and Safety Executive.
Today the fine was imposed by a judge sitting at Carlisle Crown Court.
Passing sentence, Mr Justice Openshaw said he had no doubt that BNG was guilty of serious faults and failings and had not properly discharged its public duty.
The judge initially imposed a fine of £750,000 but reduced this to £500,000 because of the guilty plea.
The leak of 83,000 litres of radioactive fluid inside the thermal oxide reprocessing plant at Sellafield was detected in April last year.
However, subsequent investigation showed the leak had begun in a fractured pipe within the THORP Plant in August 2003.
It was the latest in a series of safety breaches which has prompted the Irish Government to call for Sellafield to be shut down.
In 1983, it was discovered that on three separate occasions a mixture of radioactive waste, solvent, and water was directly discharged into the Irish Sea.
The Government insists that Sellafield, which is closer to Dublin than London, poses a serious and continuing threat to the health and safety of Irish people.