Tube Alloys the features, science and idea behind the American Fat Man implosion-type nuclear weapon. He broke down the development tasks required to replicate it, identifying outstanding questions that required further research on nuclear weapons. On 3 October 1952, under the code-name "Operation Hurricane", the first British nuclear device was successfully detonated in the Monte Bello Islands off the west coast of Australia. The Sputnik crisis and the development of the British hydrogen bomb led to the Atomic Energy Act being amended in 1958, and to a resumption of the nuclear Special Relationship between America and Britain under the 1958 US–UK Mutual
History of the Teller–Ulam design "secret"), the United States agreed to exchange some of its nuclear designs with Great Britain, leading to the 1958 US-UK Mutual Defence Agreement. The People's Republic of China detonated its first device using a Teller–Ulam design June 1967 ("Test No. 6"), a mere 32 months after detonating its first fission weapon (the shortest fission-to-fusion development yet known), with a yield of 3.3 Mt. Little is known about the Chinese thermonuclear program, however. Very little is known about the French development of the Teller–Ulam design beyond the fact that they detonated a 2.6 Mt device in the "Canopus" test in August