§ Mr. Deakinsasked the Secretary of State for Defence when the United Kingdom last conducted underground 743W tests involving nuclear explosions; if he is satisfied that these tests did not release any radioactive material into the atmosphere; and what plans he has for further underground testing.
§ Mr. ButlerThe last underground nuclear test conducted by the United Kingdom was on 1 May 1984 at the Nevada test site, in conjunction with the United States. There was no detectable release of radioactivity. I am not prepared to release information on plans for future tests.