Thursday, December 13, 2001

A mystery leak of radioactivity has been discovered under Sellafield but experts are satisfied there is no risk to workers or the public.

The contamination is from Technetium 99, a radioactive waste which has caused international concern following its appearance in the Arctic and North Atlantic.

Investigations are under way involving BNFL, the Environment Agency and the Nuclear Installations Inspectorate to find out where the technetium is coming from.

The material is a waste product arising from Magnox reprocessing and is discharged into the sea.

The mystery is whether it is appearing underground from a new leak or whether it is a legacy from a previous release of radioactivity.

There is speculation on the site that the technetium could be "historic" from the old B214 waste silo which started leaking underground in the 1970s but has now stopped.

A BNFL spokesman said: "There is no danger but we are currently investigating the source. This is the first time technetium has appeared in one of our boreholes but we have expanded the range of radionuclides we are looking for in the sampling."

The Environment Agency says it has been properly informed by BNFL of the finding.

Ian Parker, the Agency's representative on the Sellafield Local Liaison Committee, said: "Because the levels in the borehole water are extremely low we don't have any public health concerns but we need to know where it is coming from. Further work is taking place to make sure the source is identified."

He said the Agency would only consider taking enforcement action against BNFL if the source was not discovered and the contamination got any worse or out of control.

"If there is no impact on the environment generally then there is not a problem because the radiological impact is insignificant. It would be silly to say there is no possibility of it getting into water courses but none has been detected. We have a widespread environmental monitoring programme and if any technetium get into a water course it would be seen. Even if it did and water containing technetium was consumed it would have an insignificant impact. So it is not a problem in that sense - it is just that it's there and that's unusual."

Sellafield's director of operations Brian Watson broke news of the discovery to the Sellafield Local Liaison Committee, the site's health and safety community watchdog.

He said: "Technetium 99 has been detected in a small number of boreholes. The levels are extremely low and pose no threat to safety. We are monitoring further and looking at an enhanced programme of borehole construction and monitoring as part of our contaminated land study."

Tritium has been discovered in water for some time and Mr Watson added that there was a long standing underground programme of monitoring in boreholes.

Technetium 99 has been detected in Norwegian seafood but BNFL say: "Eating seven lobsters would give the same radiation dose as eating a single Brazil nut.

"When technetium is discharged from Sellafield it is diluted and dispersed in the sea. Minute quantities can be traced for thousands of miles but doses arising from it will be much smaller than even the small effects near to Sellafield. When BNFL ceases Magnox reprocessing around the year 2012 discharges of technetium will reduce even further, by more than 80 per cent."

A plant to remove the material would cost up to 200 million but would not be available for at least six years. BNFL says it is looking to see what technetium abatement technology can be developed.

Martin Forwood, of Cumbrians Opposed to a Radioactive Environment, said: "It is not the quantities, it is the fact that this stuff is there at all - and whatever else might be there."