HC Deb 01 April 1958 vol 585 c106W
58. Mr. Grimond

asked the Prime Minister what estimate he has made of the dangers of fall-out, etc., from Soviet nuclear tests; what proportion of these tests have so far been dirty; and to what extent there exist security objections to at least giving them such information as we have on clean tests.

The Prime Minister

So far as we know, all the Russian tests have caused fission products, but the hon. Gentleman will not expect me to be able to disclose all that we know on this subject.

If the last part of the Question refers to the conditions under which tests are carried out, there is no doubt that the Russians know as much as we do. If it refers to the design of bombs, obviously we cannot disclose any information on this subject.