Documents uncovered under the American Freedom of Information Act indicate that British scientists are participating in plans to extend the life of Trident warheads by up to 40 years in a programme likely to cost hundreds of millions of pounds.
Any hopes anti-nuclear protesters might have harboured that Britain might disarm once Trident became obsolete by 2020 will be dashed by the revelations. Indeed, no democratic debate on replacing Britain's nuclear deterrent will be necessary until 2050 if the programme is allowed to go ahead.
According to the documents released to the Natural Resources Defense Council, a respected American pressure group, Britain appears to be participating in a $2bn US project entitled the "Stockpile and Stewardship Management Programme" intended to design, develop, manufacture and maintain nuclear weapons capability into the next century.
Given that there is a nuclear test ban in force, it will be argued that it is only sensible, and financially prudent, carefully to maintain weapons that have been successfully tested in the past. However, two other programmes taking place under the stewardship umbrella are causing anti-nuclear campaigners anxiety.
The two schemes, the "Stockpile Life Extension Program (SLEP)" and the Submarine Launched Ballistic Missile Warhead Protection Program (SWPP)", appear to involve more than simple maintenance of missiles. The American reports, and other evidence gathered by the Campaign for Nuclear Disarmament, indicate that designs are being prepared for upgrading of missiles and a lengthening of their shelf life from 20 to 60 years.
A report on the findings by CND - which celebrates its 40th anniversary this week - will be used today to call for an urgent statement on the matter from the Prime Minister. A group of Labour MPs wants to find out if Trident is being replaced "through the back door".
The report, written by William Peden, CND's Parliamentary officer, says that the SLEP scheme involves upgrading the American W76 warhead on which the British Trident warhead is based. A number of concerned Labour MPs believe all the evidence points to British involvement in an upgrade.
According to the released documents, and a US Department of Energy, Office of Defense Programs, publication dated 29 February 1996, there is a routine exchange of information between the US and UK as part of sales agreements relating to Trident. Seventeen British scientists were stationed in the US as at January 1997.
Several members of staff from Britain's Atomic Weapons Establishment at Aldermaston are currently working at the Los Alamos National Laboratory, where the first nuclear bomb was developed. And records show that the number of visits to America by British personnel involved in nuclear co- operation has increased from 110 in 1991 to 136 in 1995.
The CND report concludes: "It would be highly unlikely, given that British nuclear weapons have the same shelf life as their US equivalents, that we are not involved in US programmes designed to extend nuclear warhead shelf life."
Academics are divided over whether an upgrade is taking place. Professor John Simpson, director of the Mountbatten Centre for International Studies at Southampton University, said the collected evidence did not point to one. However, Professor Paul Rogers, head of the Bradford University Centre for Peace Studies, said he expected one to be under way, given that the Trident system will soon be Britain's only means of delivering a warhead.
"You would expect that, since we will have only one system for the next 30 years, they will be working on ways of making it more flexible," he said. "At the very least, that amounts to an upgrade."
Alan Simpson, Labour MP for Nottingham South and one of the members who will table an early day motion in the House of Commons tomorrow, said: "Labour is committed to achieving a nuclear weapons-free world. A Trident upgrade programme hardly squares with this objective.
"Labour should cancel the project and plan to decommission nuclear weapons rather than upgrade them."Reuse content