"They're looking at this very seriously in the United States and we're calling on the Government to deal with it urgently," Mr Johnson said.Spent uranium fuel rods are transported to Sellafield from three nuclear reactor sites on the South-east – Dungeness in Kent, Bradwell in Essex and Sizewell in Suffolk. The trains, operated by BNFL's own transport company, Direct Rail Services, all pass through central London and are marshalled at Willesden before heading north. The spent fuel is contained in specially designed steel flasks and there has never been a leak of radioactivity in the 40 years the traffic has been running.But Mr Johnson said: "It has always been maintained by the regulatory authorities and the nuclear industry in this country that nuclear flasks are not a promising target for terrorists. Nevertheless, work carried out in the US before 11 September indicated that it was a credible scenario to assume that a flask could be sabotaged, and could be punctured with an explosive device."We didn't get full details from either the nuclear industry or from other bodies about the arrangements in place to deal with a terrorist threat in this country. But what we were concerned to hear was that they didn't consider it a very plausible threat which suggest that there aren't many precautions in place to deal with it. So we are calling on them to deal with it urgently."Mr Johnson added that in the US, the transport of nuclear waste by rail had been suspended after 11 September.The committee's report also pointed out that there had never been a full-scale test of all the emergency procedures in place to deal with a nuclear rail accident in London, and suggested this should take place as soon as possible.A spokesman for BNFL said last night: "We get advice on our security from the Government.

Since 11 September this has been looked at and we have been allowed to continue with these transports."A spokesman for the Energy minister said last night: "The Office of Civil Nuclear Security, which is an independent office with the Department of Trade and Industry, is looking at this.". Stephen Byers, the Transport Secretary, shrugged off Tory calls for him to resign yesterday as he mounted a staunch defence of the decision to put Railtrack into receivership. Stephen Byers, the Transport Secretary, shrugged off Tory calls for him to resign yesterday as he mounted a staunch defence of the decision to put Railtrack into receivership.In an emergency Commons statement, Mr Byers revealed it was the privatised firm's advisers who first raised the idea of declaring insolvency because its finances were so dire. Railtrack had also decided to pay its shareholders a £88m dividend earlier this month despite "coming with a begging bowl to Government month after month", he said. To cheers from Labour MPs, Mr Byers confirmed that he wanted to create a not-for-profit private company to take over Railtrack and vowed not to pay any more taxpayers' money to its shareholders. The new company would work along commercial lines but invest all surplus back into the network, as well as ending the split between track and wheel that had undermined the whole system.Mr Byers claimed the new structure would bring "an end to the self-defeating system of penalties and compensation" and "an end to perverse incentives".

He said he had decided to act after the Railtrack chairman, John Robinson, had told him in July that the firm's financial position was far worse than it was thought in April. "It was obvious that the company could not continue unless we offered to fund whatever losses they might have had for a period of several years. I took the view that I simply could not responsibly enter into such a guarantee on behalf of the .. taxpayer. I decided that I could not give Railtrack a blank cheque," he said. In a letter to Railtrack last night, Mr Byers indicated he would allow the company access to funds from its ownership of the Channel Tunnel Rail Link.Steve Marshall, Railtrack's chief executive, accused Mr Byers of being "seriously misleading in significant respects" in the account he gave MPs. The company indicated it could still launch legal action against the Government and the Rail Regulator, Tom Winsor, for failing in his duty to act in a way that would enable Railtrack to finance its activities.The Railtrack Shareholders' Action Group, which represents investors owning more than 30 per cent of the company, also criticised the Secretary of State.

"We are extremely disappointed at the cavalier way Mr Byers has written off the legitimate expectations of shareholders who paid ... £2bn to the Government in 1996 for the ownership of Railtrack and the railway infrastructure and are now having that infrastructure removed .. without compensation.". President Bush's war against global terrorism is destined for failure, the former head of MI5, Stella Rimington, warned yesterday. President Bush's war against global terrorism is destined for failure, the former head of MI5, Stella Rimington, warned yesterday. Dame Stella, who was speaking about the military action in Afghanistan, said that terrorism could never be wiped out altogether. And she warned that there could be a repeat of the attack on New York because the intelligence network was not advanced enough.The former director general, a diplomat's wife who rose to the highest position within the intelligence service before retiring five years ago, was speaking at the Cheltenham Literary Festival in Gloucestershire to promote her autobiography, Open Secret.She said: "I do not feel incredibly confident about this war against terrorism. I think it is encouraging to see that there is better, closer collaboration between the world's intelligence agencies. That is quite positive, but rooting out terrorism strikes me as an extremely difficult thing to do."Terrorism is with us.