Thursday, March 07, 2002

A SELLAFIELD contractor received nearly a full year's radiation dose in the space of only half an hour after being contaminated by a robotic arm, magistrates at Whitehaven were told yesterday.

The incident happened over a year ago in the Thorp reprocessing plant and Tony Johnston, the contract scaffolder, has been off work ever since because of a stress disorder.

BNFL was prosecuted for allowing him to be exposed to radiation, failing to take all necessary steps to restrict the exposure and also failing to make a proper assessment of the risk. The company pleaded guilty to the three charges and was fined a total of 15,000 and ordered to pay 4,166 costs.

"No one will know the true effect of the exposure for many years to come," said Simon Parrington, prosecuting for the Health and Safety Executive.

"There was a lack of control and failure to carry out a risk assessment. BNFL should have done more to ensure his safety. It caused immediate distress to Mr Johnston."

Mr Johnston, employed by Cape Industrial Services, was working in a high radiation cell fitting handrails to a scaffold platform when the radiation alarm he was wearing on top of his protective PVC suit started to bleep faster than normal. He was working within a foot of the jaws of a robot, called the server manipulator in the crane maintenance cell of the Thorp head end.

"He must have brushed against it to suffer the exposure," Mr Parrington said.

The manipulator arm was contaminated by radioactive particles and, despite his protective clothing, the scaffolder received 430 millisieverts of radiation in half an hour compared to the legal limit of 500 Ms in one year.

BNFL's legal representative Andrew Carr said: "It should not have occurred. Steps should have been taken to identify and remove the hazard."

However, he added: "Whether this level of skin dose is received in one go or in one year does not increase the risk. His long-term risk will not be greater than his colleagues or other Sellafield workers."

The incident arose when Mr Johnston was allowed entry into the highly active maintenance cell after a change over of BNFL engineering shift team leaders.

An initial check correctly identified the manipulator as a hazard but its robotic arm could not be surveyed because it was too high for a health physics monitor to reach. A team was sent into the cell to carry out clean up work at ground level only. The scaffold was moved but not far enough away from the manipulator.

"Ideally, it should have been taken out of the cell or covered over.

"The incoming shift team leader did not know precisely where the server manipulator was located," said Mr Carr