Radioactive material may be leaking from forgotten trenches of nuclear waste dumped at the Sellafield reprocessing site during Britain's atomic weapons programme in the late 1940s and early 1950s.
The trenches are believed to be the source of "tritium springs" - streams discharging radioactive hydrogen on to the beaches at Sellafield. The trenches were covered over with hardcore and asphalt and are currently used as hardstanding for construction materials and occasionally to park contractors' vehicles.
The existence of the trenches came to light following inquiries by experts investigating clusters of childhood leukaemia in the area - the Committee on the Medical Aspects of Radiation in the Environment (Comare). But neither Comare, British Nuclear Fuels (BNFL) nor the Nuclear Installations Inspectorate was able to say what was contained in the radioactive waste dump.
A spokesman for BNFL said: "The material is mainly low- level waste although we cannot discount the fact that there may be small quantities of solid, intermediate-level waste. We are checking contemporary records."
Government policy is that intermediate-level waste is so radioactive that it should be disposed of in a highly engineered repository at least 600m underground, not in a trench, just a few feet below the surface.
The Nuclear Installations Inspectorate pointed out that when the waste was dumped, the site had Crown Immunity. "We weren't in charge at the time, or the records would be meticulous. It is probable that intermediate- level waste is there, but we don't know. We do not think it is a desirable situation and are discussing with British Nuclear Fuels what steps can be taken.''
Earlier this year, Comare was dismayed to discover that it had not been told about an explosion in a waste shaft at Dounreay, in the north of Scotland, which was suspected of being the source of "hot" radioactive particles on the foreshore. The Dounreay explosion prompted Comare to ask if there were sources of radioactivity at other sites.
The committee is worried by the lack of information it has received. The current chairman of Comare, Professor Bryn Bridges, of the University of Sussex, said: "Comare is aware of the existence of this trench and is interested in knowing what it contains but has no further information at this time."
Technically, BNFL has legal responsibility for the trenches, because it holds the nuclear site licence for Sellafield. But the trenches contain wastes which predate not only BNFL but also the UK Atomic Energy Authority. They were created by the forerunner of the Ministry of Defence's procurement executive.
A Comare member said: "There is a general trend that can be seen here. Relevant information is not always laid out in front of you in a way you can made sense of. Although it is cock-up rather than conspiracy, one does find out over a period of time a number of things one would have liked to have known right at the beginning of an investigation."
Despite a reluctance to speak about the trenches because of lack of information, members of Comare believe it would not be a sufficient source of radioactivity to explain the clusters of leukaemia around Sellafield. The NII concurred, saying that it did not believe staff on site would get excessive doses when working in the area.Reuse content