BRADWELL: Radioactive leak at nuclear plant
The radioactive cocktail of tritium, caesium, cobalt and americium that leaked from a decontamination unit was not discovered until the twin reactors were decommissioned five years ago.
The Environment Agency accused Magnox Electric Ltd at Chelmsford Crown Court of unlawfully allowing the leak to occur and failing to maintain its waste disposal system between 1990 and 2004.
Magnox, originally known as Nuclear Electric Plc, took over the power station from the Central Electricity Generating Board on March 31, 1990, following privatisation.
Represented by its company secretary Dr Michael Cogbill, Magnox denied 11 counts of breaching the Radioactive Substances Act between 1990 and 2004.
Prosecutor Mark Harris, for the Environment Agency, said the radioactive waste leaked from a poorly designed sump in the decontamination unit that was installed in 1976, 14 years after the power station began supplying electricity to the national grid.
Mr Harris said Bradwell power station was once able to supply electricity to an area the combined size of Chelmsford and Colchester.
He told the jury that the precise dates of the leaks were not clear, but the charges were based on the evidence of the material discovered on the ground.
He said: "I am going to show you how it got there which, taken together with the evidence, will drive you to the irresistible inference that it was escaping over a period."
He said the waste should have been filtered through cleaning baths and made safe before being discharged into the River Blackwater.
Mr Harris told the jury it was important for them to realise that the radioactive waste was not simply flushed into the estuary.
He added: "The idea was that it would be appropriately treated.
"But it was simply escaping into the ground and had not undergone subsequent treatment."
He said the power station closed in 2002 and all the nuclear fuel was taken to Sellafield in 2006.
He added: "The leak was discovered after it ceased to be operational, but before the fuel was removed.
"A lot of research and exploration of where the leaks occurred and what the cause was has since taken place."
Judge Peter Fenn warned the jury not to attempt to conduct their own research into nuclear physics and said all the relevant material would be heard in court.
The trial continues.
