§ Mr. Cook asked the Secretary of State for Defence to what extent the United Kingdom has been exporting plutonium to the United States of America for use in its weapons programme in exchange for importing highly enriched uranium; under what agreements of what duration such exchanges have taken place; over what duration the exchanges have actually taken place; whether they are currently taking place and what are the plans for the future; what quantities of plutonium and highly enriched uranium have been and are involved; for what purpose the United Kingdom has used, is using and is intending to use the highly enriched uranium; and what is the source of the plutonium involved, whether from Calder Hall and Chapelcross stations or other Magnox stations.
§ Mr. Pattie: The 1958 agreement between the United Kingdom and the United States on co-operation on the uses of atomic energy for mutual defence purposes provides for transfers of special nuclear materials between the two countries, but it has been the normal practice of successive Governments not to reveal details of such exchanges.