Claws and the law: How safe is our seafood if Thorp gets the go-ahead? asks Nicholas Schoon

This Friday, in the High Court, Mr Justice Potts will make a judgment that could make or break British Nuclear Fuels' Thorp plant on the Cumbrian coast. Lobsters are on his mind.

It turns out that the people most at risk from Thorp's radioactive emissions are the serial lobster-eaters of Lancashire and Cumbria. Consuming the kings of crustacea from that corner of the Irish Sea may, it has been argued, take you over the official annual safety limit once the pounds 2.8bn nuclear reprocessing plant goes into operation.

Some of the slightly radioactive local lobsters may even be eaten by senior politicians and trade unionists after a hard day at conference in Blackpool. But it seems unlikely they could devour enough in a few days to take them beyond the safety limit. The lobster question occupied a substantial chunk of eight and a half days of weighty and expensive legal argument before the judge in the High Court earlier this month.

The occasion: the judicial review hearing into last December's decision by John Gummer, the Environment Secretary, and Gillian Shephard, Agriculture, Fisheries and Food Minister, to authorise radioactive emissions from Thorp into the air and the Irish Sea. Greenpeace and Lancashire County Council's barristers requested the judge to tell the ministers that they should have held a public inquiry before making a decision.

Lobsters accumulate technetium 99 in their tissues. This is an obscure radioactive element, unknown in nature, that will be produced in small quantities by operations at British Nuclear Fuels' Thorp plant at Sellafield, Cumbria, along with other radionuclides.

The Government had argued that the 'critical group' - those deemed most at risk from Thorp's radioactive emissions - were fishermen, bait diggers and their families, who ate large quantities of seafood. The radioactivity would accumulate in seabed sediments and the crustacea, molluscs and fish living on and above them.

According to Ministry of Agriculture, Fisheries and Food (MAFF) scientists, those seafood eaters would receive a maximum dose of 0.214 milliSieverts (mSv) per year attributable to all of British Nuclear Fuels' operations at Sellafield, including Thorp. The maximum dose limit allowed for the general public due to any one nuclear site is 0.5mSv. So, no problem. If the group reckoned to be receiving the biggest Thorp dose outside the plant was safe, then so was the rest of the public.

But Lancashire County Council maintained that government scientists could have underestimated the dose of radioactivity. Its barrister, Nicholas Blake, said MAFF's scientists had assumed a maximum annual lobster consumption in the critical group's diet of 2kg a year - about three sizeable crustacea. Once Thorp is operational, each kilogram of lobster will contain about 0.015mSv.

If substantially more lobsters were eaten, their radioactive content combined with that from other local seafood could readily take an individual's dose above the limit, the council feared. Mr Blake explained that Lancashire had carried out its own survey of 39 people at the fishing port of Fleetwood just before Christmas. This found 16 lobster-eaters who claimed to eat anything between 2kg and 24kg a year - almost one a week.

Outside the court, however, there was some scepticism. Bill Madine, a fisherman from the port of Whitehaven, near Thorp, said lobsters were a special treat, and those caught were sold. 'Fishermen can't afford to eat them . . . I've had about five in my lifetime.' They fetch about pounds 4 per lb.

Bill Scott, who serves them at his River House restaurant at Skippool near Blackpool for pounds 25 (including vegetables and VAT) shrugged off the threat. 'The emissions from Sellafield have been more and more tightly controlled and I think the risks are minuscule.'

The lobsters Mr Scott sells, however, are as likely to come from Scotland or the United States as from the Cumbrian and Lancastrian coast.

(Photograph omitted)