A top scientist has used Ribena to demonstrate how nuclear waste was dealt with at a power station.

A court has heard how there was an alleged leak of nuclear waste from a site at Bradwell power station for 14 years before the problem was discovered.

The owners of the former power station face a total of 11 charges, brought under the 1993 Radioactive Substances Act, of unlawfully allowing waste to leak from a decontamination unit.

The alleged leaks lasted for 14 years, from March 1990 to February 2004, and had come from a sump tank at a decontamination unit used for waste from the power station.

Prosecutors from the Environment Agency have alleged the poor original design of the sump and no regular inspections or maintenance of the sump until after the leak was discovered, in February 2002, were to blame.

The waste involved in the alleged leaks included tritium, cobalt, caesium and americium, and they leaked into the ground before treatment that would have made it safe for disposal into the Blackwater estuary.

The trial has heard the sump was used for the collection of radioactive liquid waste from cleaning work in the decontamination bay.

The intention was the sump would collect all the waste. It was fitted with a pump and a level-activated switch which, when the sump was full, started the pump and pumped the waste through to the effluent treatment plant.

It was then processed to a safe level and should eventually have been discharged into the River Blackwater.

Physics expert Dr John Hassard set up a series of tanks in court to simulate the sump and the pump, with one tank on the judge’s bench and another on the witness box.

One was filled with water and Dr Hassard added Ribena to the other tank to represent nuclear waste before pouring water from one tank into the other to dilute the “waste.”

The doctor told the jury the aim was to show how the process worked.

He also told the jury he had examined many reports in connection with the alleged leaks and had come to the conclusion that the sump may not have been the only cause of the problem.

“I cannot exclude the sump, but cannot exclude other factors,” the doctor told the jury.

  • The trial continues