Nuclear fission Mexico, which was the scientific hub for research on bomb development and design. Other sites, notably the Berkeley Radiation Laboratory and the Metallurgical Laboratory at the University of Chicago, played important contributing roles. Overall scientific direction of the project was managed by the physicist J. Robert Oppenheimer. In July 1945, the first atomic explosive device, dubbed "Trinity", was detonated in the New Mexico desert. It was fueled by plutonium created at Hanford. In August 1945, two more atomic devices – "Little Boy", a uranium-235 bomb, and "Fat Man", a plutonium bomb – were used against the Japanese cities of Hiroshima
Soviet atomic bomb project control of the atomic bomb project by establishing a special committee to oversee the development of nuclear weapons as soon as possible. On 9 April 1946, the Council of Ministers created KB–11 ('Design Bureau-11) that worked towards mapping the first nuclear weapon design, primarily based on American approach and detonated with weapon-grade plutonium. From this point, the work on the program was carried out quickly, resulting in the first nuclear reactor near Moscow on 25 October 1946. From 1941–46, the Soviet Union's Ministry of Foreign Affairs handled the logistics of the atomic bomb project, with Foreign Minister Vyacheslav Molotov controlling