 |
| HMS
Vanguard carries Britain's nuclear deterrent, Trident
C4 W76 missiles. |
British and American nuclear warheads
carried by submarines are so poorly designed that they
may fail to detonate if fired, scientists have said.
The news emerged after interviews with
a group of American scientists with ties to the Los Alamos
nuclear research facility, where the first atomic weapon
was manufactured.
One of them, Richard Morse, of the University
of Arizona and a former Los Alamos weapons designer, said
the casing of the W76 nuclear warhead was so thin that
it would probably fail if used. The British Trident warhead,
the country's sole nuclear weapon, is based on the W76.
Mr Morse said: "What is out there
on those boats is at best unreliable and probably much
worse."
The claims have been vigorously denied
by US officials, who say that the warhead "looks
like a pretty good weapon". They say the warheads
have not been tested for 13 years because of the global
moratorium on the testing of nuclear weapons but were
successfully detonated before then.
Everet Beckner, the head of the nuclear
arsenal at Los Alamos, said there were no plans to redesign
the W76 but admitted to the New York Times that that could
change.
The story emerged after what was described
as "acrimonious" exchanges between worried scientists
and the leadership of America's nuclear weapons programme.
That led four scientists, three of them
former Los Alamos employees and one still working there,
to seek a secret meeting with weapons officials to discuss
their fears.
They met in March last year. Dr Morse
said: "It was a verbal mud-wrestling match. Officials
from Los Alamos and the government would not be candid
with us. We told them things they did not know."
The issue is of central importance despite
the end of the Cold War. Countries such as North Korea
and Iran are pursuing nuclear programmes that Washington
believes have a military goal. Both have active and ambitious
long-range missile programmes.
Britain's nuclear weaponry, thought to
number about 190 warheads, is carried exclusively aboard
the four Trident submarines, Vanguard, Vigilant, Vengeance
and Victorious.
While America still has air-launched nuclear
weaponry, it too has become more dependent on its submarine
missiles. Dr Morse said the growing reliance on submarine
weaponry had revived his long-standing worries about the
casings of the W76.
During the 1970s there was pressure to
make warheads as light as possible to allow more to be
fitted on top of a relatively thin missile. Although the
radiation casing was made of uranium, which is double
the weight of lead, it was to be super-thin - in places
only as thick as a beer can.
The casing is critical because it has
to hold together for nanoseconds as the nuclear chain
reaction begins, releasing temperatures hotter than the
surface of the Sun. If the case fails, the bomb can fail
too or explode with less than its intended force.
|
