Operation Grapple with the American Manhattan Project in August 1943. Many of Britain's top scientists participated in the British contribution to the Manhattan Project. After the war, fearing that Britain would lose its great power status, the British government resumed the atomic bomb development effort, now codenamed High Explosive Research. The successful test of an atomic bomb in Operation Hurricane in October 1952 represented an extraordinary scientific and technological achievement, but Britain was still several years behind the United States in nuclear weapons technology. In July 1954, the Cabinet decided to develop the hydrogen bomb. The United Kingdom Atomic Energy Authority Atomic
Soviet atomic bomb project (including those now in Kazakhstan). The uranium for the Soviet nuclear weapons program came from mine production in the following countries, RDS-1, the first Soviet atomic test was internally code-named "First Lightning" ("Первая молния", or Pervaya Molniya) August 29, 1949, and was code-named by the Americans as "Joe 1". The design was very similar to the first US "Fat Man" plutonium bomb, using a TNT/hexogen implosion lens design. On September 24, 1951, the 38.3 kiloton device RDS-2 was tested based on a tritium "boosted" uranium implosion device with a levitated core. This test was code named "Joe 2" by the