British hydrogen bomb programme Atomic Energy Act of 1946 (also known as the McMahon Act) ended technical cooperation. Fearing a resurgence of American isolationism, and the loss of Britain's great power status, the British government resumed its own development effort, which was codenamed "High Explosive Research". The successful nuclear test of a British atomic bomb in Operation Hurricane in October 1952 represented an extraordinary scientific and technological achievement. Britain became the world's third nuclear power, reaffirming the country's status as a great power, but hopes that the United States would be sufficiently impressed to restore the nuclear Special Relationship were soon dashed. In November
Atomic demolition munition and all were removed from stockpile by 1966. A weapons effect test of the TADM was made in the 1962 Johnny Boy ("Johnnie Boy") shot of the Dominic II series (which is more accurately referred to as Operation Sunbeam), the yield of Johnny Boy/Johnnie Boy was about .5 kt. A preceding ADM test which resulted in a comparable yield, was test shot "Danny Boy" of Operation Nougat, also producing a yield of about 0.5 kiloton. The "Special Atomic Demolition Munition (SADM)" was a family of man-portable nuclear weapons fielded by the US military in the 1960s, but never used in