Peter Luff, MP for Mid Worcestershire and Parliamentary Under Secretary of State at the Ministry of Defence, published a letter in reply to a question from Paul Flynn MP about the number of visits to US establishments by personnel from the UK Atomic Weapons Establishment. The table below is a summary. Hansard 20.1
Los Alamos, Sandia and Lawrence Livermore are all at the heart of the US nuclear weapons establishment. Mr. Luff said that the visits were made under the 1958 US-UK Mutual Defence Agreement.
In 2004, it was renewed. President Bush said that it “extends for 10 years (until December 31, 2014) provisions that permit the transfer of non-nuclear parts, source, by-product, special nuclear materials, and other material and technology for nuclear weapons and military reactors. … I have concluded that it is in our interest to continue to assist [the UK] in maintaining a credible nuclear force”.
CND campaigned against renewal, saying that it broke the terms of the Non-Proliferation Treaty, article 1 of which says, “Each nuclear weapon State Party to the Treaty undertakes not to transfer to any recipient whatsoever nuclear weapons or other nuclear explosive devices or control over such weapons or explosive devices either directly or indirectly”.