Windscale fire had little impact here

WITH reference to the letter from Adi Roche (October 11) concerning, among other things, the Windscale reactor fire in October 1957, I would like to respond as one of the authors of the recent study of the accident.

Although not perfect, substantial information on the release of radioactive material from the Windscale reactor (at Sellafield) and the subsequent travel of the plume was published soon after the accident.

One of the original scientific papers, presented to a UN conference in 1958, has been reproduced in Journal of Radiological Protection, with an accompanying editorial by me (www.iop.org/journals/JRP).

Our latest work makes use of a large computer program from the UK Met Office and digitised weather data which was not available 50 years ago.

Our study does indeed show that the amount of radioactive material released during the fire was about double that of prior estimates, but this was due to part of the plume swinging out over the North Sea in the early stage of its progress, which was not appreciated before.

This increase does not affect the previous estimates of intakes of radioactive material by people since these are based on environmental measurements that are obviously not influenced by the predicted passage of some of the radioactivity over the North Sea.

Our study also confirms that Ireland was predominantly unaffected by the fire.

A few days after the accident, the far western edge of the plume swirled back up the Irish Sea.

This edge may have just brushed the east coast of Ireland, but the cloud was very diluted by this time.

This finding of very little (if any) impact is consistent with measurements of environmental radioactivity made in Ireland during 1957.

Richard Wakeford

Visiting Professor

The Dalton Nuclear Institute

University of Manchester

England