The move by Greenpeace is part of an intensification of the campaign by environmental pressure groups against the Cumbrian nuclear plant. They believe that the Government's decision is "the writing on the wall" for Sellafield also.
Ministers are equally determined to resist the new attack on Sellafield. And the first shots in a new international battle over the future of the plant are likely to be fired at a special conference on sea pollution this month.
Greenpeace has taken samples from the sea bed at the end of the pipe through which Sellafield discharges waste and says that they show dangerous levels of radioactivity. They are presenting results to the government in Dublin, angry at the plant's pollution of the Irish sea.
Other northern European countries are alarmed and the issue will come to a head this month at a meeting of the Oslo and Paris Commissions on Sea Pollution, which is likely to see renewed calls for all radioactive discharges to sea to be stopped.
This would spell the end of nuclear reprocessing, which separates uranium, plutonium and nuclear waste from used nuclear fuel and is responsible for most of the discharges to sea. This is the main activity at Dounreay, which is now to be phased out after the UKAEA, which owns the plant said there was "no economic case" for supporting it in the longer term.
Ministers insist that the problem is confined to Dounreay, which has been hit by a disastrous series of accidents. But environmental groups point out that Sellafield is also accident-prone and that the economics, even of its modern Thorp reprocessing plant, are increasingly in doubt.
The purpose of reprocessing is also doubtful, as the plutonium and uranium it was designed to produce are no longer needed.
Peter Melchett, the executive director of Greenpeace, said last night: "All the factors that condemned Dounreay also stack up against Sellafield." Dr Patrick Green, senior nuclear campaigner for Friends of the Earth, is considering taking legal action to ensure that the viability of the Thorp plant is reviewed.
A spokesman for British Nuclear Fuels, which runs Sellafield, said its reprocessing business was quite different from that at Dounreay. It reprocesses large amounts of used nuclear fuel, while Dounreay treated much smaller amounts of specialist material.Reuse content