[NYTr] Brit 1957 Nuke Accident Fallout Underestimated - BBC

[All the News That Doesn't Fit]

BBC - Oct 6, 2007
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/7030536.stm

Windscale fallout underestimated

by Rebecca Morelle
Science reporter, BBC News

The radioactive fallout from a nuclear accident that rocked Britain 50
years ago was underestimated, scientists say.

In 1957, a fire at the Windscale nuclear reactor in Cumbria led to a
release of radioactive material that spread across the UK and Europe.

But new research claims the incident generated twice as much
radioactive material and caused dozens more cancers than was previously
thought.

The research was published in the journal Atmospheric Environment.

Risky act

The Windscale site was home to Britain's first two nuclear reactors -
the Windscale Piles - which were constructed to produce plutonium and
other materials for the UK's nuclear weapons programme.

But the rush to build them at a time when little was known about
nuclear reactors led to disaster.

On 10 October 1957, a failure to properly control the temperature of
graphite control rods within the reactor sparked a devastating fire,
which caused radioactive contamination to spew into the atmosphere.

The fire was eventually put out with water - a risky act which could
have caused an explosion - but a radioactive cloud was already
spreading far and wide.

At the time of the accident the levels and spread of the radioactive
materials was estimated, and measures were put in place to limit
radioactive contamination.

But a new study carried out by John Garland, formerly of the UK Atomic
Energy Authority, and Richard Wakeford, a visiting professor at the
University of Manchester, suggests the contamination of the environment
may have been much higher.

The team carried out a re-analysis of data taken from environmental
monitoring of air, grass and vegetation and combined this with computer
models that revealed how the radioactive cloud would have spread from
the reactor with the meteorological conditions at that time.

They confirmed radioactive iodine and caesium were released, as well as
polonium and a very small amount of plutonium, but found that the
levels would have been higher than previously thought.

John Garland said: "The reassessments showed that there was roughly
twice the amount than was initially assessed."

This would have also impacted the numbers of cancers that the accident
would have caused, said the authors.

Previously, it was thought that the radiation would have eventually led
to about 200 cases of cancer, but the new contamination figures suggest
it could have caused about 240.

The researchers said most of the radioactive materials released had now
decayed and posed no ongoing risk, but small quantities of caesium and
plutonium remained.

Paul Howarth, director of research at the Dalton Nuclear Institute at
Manchester University, said a repeat of the Windscale incident would
not happen today because the design of modern nuclear reactors was
completely different.

© BBC MMVII