Defence plutonium inventories and international safeguards in the UK

The UK Ministry of Defence's (MOD) publication Plutonium and Aldermaston: An Historical Account is a valuable report because it increases transparency and openness with regard to the UK's military fissile material holdings. The report does not fulfil the precise mandate set out in the government's 1998 Strategic Defence Review. The MOD then committed itself to providing an account of fissile material production. Instead, it has reported on fissile material transfers to and from the Atomic Weapons Establishment at Aldermaston (AWE) in the period 1952 to 1999. On 31 March 1999, the UK defence stockpile of plutonium comprised 3.51 tonnes. The report also discloses that physical stocks of plutonium at Aldermaston exceed recorded net deliveries to the site by 0.29 tonne (the inventory difference). The study reveals that the AWE acted as the centre of plutonium processing for both civilian and military programmes in the UK. The civilian work was largely phased out in the 1970s. To further increase transparency and meet stated disarmament objectives, the Department of Trade and Industry and MOD should launch a joint study of defence fissile material production, encompassing both plutonium and highly enriched uranium. A new table shows that the coverage of international safeguards in the UK is extensive. France is the only other state with a recognised nuclear weapon programme that approaches the UK in its safeguards coverage. The UK's withdrawals of fissionable material from safeguards since 1978 have recently been made public. It would be a significant step to strengthen safeguards if the UK were to announce that in the future it will not withdraw any nuclear material from international safeguards. (author)