§ Lord Jenkins of Putneyasked Her Majesty's Government:
Whether in the light of the publication by the United States Department of Energy on 27th June this year of fact sheets making clear that the US conducted a successful nuclear warhead test in 1962 using reactor trade plutonium imported from the United Kingdom they will reconsider the replies given by Viscount Cranborne on 2nd November 1992 (column WA113) and Baroness Chalker of Wallasey on 28th June 1993 (column WA21) that "the usefulness of reprocessed plutonium for weapons purposes depends on its composition" and that the United Kingdom Government "would only allow the export of plutonium from reprocessing if we had received satisfactory assurances that it would only be used for peaceful non-explosive purposes"; and how often British reactor grade plutonium has been export to the US and used for military purposes since 1962.
§ Lord HenleyThe statement by my noble friend Viscount Cranborne of 2nd November 1992 and that by ny noble friend Baroness Chalker of Wallasey on 28th June 1993 are both consistent with the US announcement of 27th June 1994. Although the US conducted a nuclear test in 1962 involving an experimental nuclear device constructed from reactor grade plutonium, there would be significant technical difficulties in designing, manufacturing and storing a weapon using such material. It remains the case that the usefulness of plutonium for weapons purposes depends on its isotopic composition. Plutonium originating from 83WA the United Kingdom civil nuclear programme is subject to international safeguards and we permit its export only when we receive satisfactory assurances that it will be used for peaceful non-explosive purposes. As a nuclear weapon state, the United Kingdom maintains military reactors outside safeguards for the production of nuclear material for defence purposes. The plutonium used in the 1962 test in the US was produced in these military reactors and was sent to the US under the terms of the 1958 Mutual Defence Agreement. It is not our practice to give details of the nuclear materials sent to the US under these arrangements. However, assurances have been given by the US in respect of plutonium from the United Kingdom generating board reactors, which has been consigned under this agreement since 1964.