Letter: Plutonium porridge of strange consistency

Sir: The 'confirmation' by British Nuclear Fuels (BNFL) that reactor-grade plutonium used in the 1962 Nevada bomb test 'had come from its Calder Hall and Chapel Cross reactors' ('US made atomic bomb with fuel from British reactors', 29 June) is at variance with the evidence given to the Sizewell public inquiry by a team of three BNFL experts.

The evidence was that plutonium from Calder Hall and Chapel Cross was processed separately from that from the 'civil' reactors of the two electricity boards only if the plutonium from Calder Hall and Chapel Cross was of weapons-grade. Reactor-grade plutonium, said BNFL, was always 'co-processed'.

According to this evidence, the reactor-grade plutonium used in the Nevada bomb test was a porridge of plutonium from Calder Hall, Chapel Cross and the electricity board power stations. On average, more than 80 per cent of the porridge is from the electricity board power stations.

Yours sincerely,

R. V. HESKETH

Berkeley, Gloucestershire

30 June