§ Mr. Alfred Morrisasked the Prime Minister what proportion of the plutonium transferred to the United States of America from the United Kingdom under the 1958 mutual defence Agreement came from (a) military reactors, (b) civil reactors of the generating boards, (c) reactors of British Nuclear Fuels Ltd. and (d) other sources.
§ The Prime MinisterThe proportion of the Plutonium exported to the United States under the barter arrangements prior to 1971 from these sources cannot be given for national security reasons, since this information could be of use in calculating the total quantity of 5W plutonium sent, and hence the quantity of highly enriched uranium received in return by the United Kingdom for defence purposes.