RADIOACTIVE MATERIAL has contaminated groundwater around the Sellafield nuclear complex in Cumbria, it was confirmed this week.
Tests are continuing after the Nuclear Installations Inspectorate (NII) revealed last week that Technetium 99 was discovered in a borehole last November by British Nuclear Fuels Limited (BNFL).
'The NII has requested BNFL's proposals for control of the radioactive material that has entered the ground and expects to receive this soon, ' an NII statement said.
'BNFL is carrying out further investigations to find out how much Technetium 99 had leaked and whether any more substances had also leaked into the ground, ' a spokesman told NCE.
Both the NII and BNFL said that the quantities discovered so far posed no public risk.
'There is no immediate cause for concern, ' said the spokesman. 'BNFL has been working hard to ensure that there is no hazard to the public.'
The NII said that the Technetium 99 was first discovered in boreholes last November. It has a half-life of over 200,000 years and has been found in shellfish off the Irish and Norwegian coasts.
The NII said the source of the leak was believed to be sludge storage tanks in a building known as B241. These hold around 3,000t of intermediate level waste.
'These old tanks have been suspected to be leaking for some years and recent modifications have been made to address this, ' a NII statement said.
A November 1998 NII report stated: 'The B241 (tanks) constructed in the early 1950s are considered to be in an unacceptable condition for long term storage. The pre-stressed concrete tanks have shown serious signs of deterioration, including corrosion of reinforcement, cracking of the concrete and seepage.'
Nearly £100M was spent on remedial works and construction of a sealed building around the tanks in 1998 to enable emptying of the tanks. This is due to start this year but dependent on NII approval.
Nuclear consultant John Large told NCE: 'These buildings are being used well past their design life to store radioactive waste which has outstayed its welcome. BNFL seems always to be fighting a rearguard action.'