The Independent on Sunday has learnt that the Department of the Environment, Transport and the Regions has instructed the Health and Safety Executive and other agencies to check on radioactive fuel flasks.
The move was prompted by a backbench Labour MP who wrote to John Prescott, the Deputy Prime Minister, over plans by BNFL to store trains carrying spent fuel in a London suburb for 15 hours each week.
BNFL wants to use sidings at Cricklewood, north London, to marshal trains bringing fuel from three power stations - Sizewell in Suffolk, Brandwell in Essex and Dungeness in Kent - on their way to its reprocessing plant at Sellafield.
The plan has sparked local outrage as residents fear a train could be derailed because of vandalism on the line. Some parents want to withdraw their children from local schools. Environmental pressure groups believe the flasks "sweat" radioactive material that could be fatal if released into the atmosphere.
John Reid, the Transport minister, told the IoS: "I am aware of public concern on this issue and, as part of our ongoing programme of independent checks on the effects of the transportation of radioactive material on health and the environment, we will be sponsoring independent checking of contamination levels on radioactive packages, concentrating on irradiated fuel flasks."
BNFL used nearby secure marshalling yards until it switched the contract for moving all its spent fuel, from English, Welsh and Scottish Railways to Direct Rail Services, a BNFL subsidiary.
Rudi Vis, MP for Finchley and Golders Green, said the decision to use its own rail company and move the marshalling to Cricklewood was motivated by money. He said: "I find it totally unacceptable that thousands of people have to live in fear in order for an arrogant company to make a few extra pounds. I want to get this out of London."
The company has been taken aback by the strength of local anger. It admits its handling of the issue has been a public-relations disaster - the plans emerged after BNFL informed the wrong council and MP of its intentions. A spokeswoman for Barnet council, which opposes the plan, said: "This has led us to question BNFL's knowledge of the area and further raises issues of security and safety."
BNFL last week told residents it had delayed plans to start using Cricklewood immediately in order to have "dialogue" with local groups. But it insists that dialogue does not mean negotiation, as it intends to press ahead eventually, however strong the opposition.
Linda Hayes, head of a local residents' group co-ordinating the opposition, said: "BNFL wants to bring three trains and place them at the bottom of our gardens for 15 hours. All the residents are up in arms. This is borough- wide and we have had so much support it is becoming London-wide."
A BNFL spokesman said: "It is painfully clear that we have misjudged the mood of local people. We would be very arrogant to say anything else. What we want to do is to continue dialogue with local representatives to give us an opportunity to put our side of the story."
He said the flasks, made from forged steel more than 30cm thick and typically weighing more than 50 tonnes, were safe. "The heavy shielding of the flasks absorbs radiation and means there is absolutely no danger to train crew, depot staff or local residents. Cricklewood is a very densely populated area but, without wishing to sound dismissive, in terms of safety it does not matter where we transport it through."
He said BNFL puts the flasks through a series of tests, including dropping them from a height of 9m onto reinforced concrete. In 1984 a flask was put across a rail line at a British Rail testing station and a 100mph train driven at it. "The train was a write-off but the flask was fine. There was only superficial damage. The flask is capable of surviving a lot more than a derailment."
n In last week's story, "Nimbys ambush fast rail project", we referred to Helen Bryan as a "former" barrister. We are happy to point out that Ms Bryan is still a barrister.