Soviet atomic bomb project

The Soviet atomic bomb project was authorized by Joseph Stalin in the Soviet Union to develop nuclear weapons during and after World War II. Physicist Georgy Flyorov, suspecting a Western Allied nuclear program, urged Stalin to start research in 1942. Early efforts were made at Laboratory No. 2 in Moscow, led by Igor Kurchatov, and by Soviet-sympathizing atomic spies in the US Manhattan Project. Subsequent efforts involved plutonium production at Mayak in Chelyabinsk and weapon research and assembly at KB-11 in Sarov. After Stalin learned of the atomic bombings of Hiroshima and Nagasaki, the nuclear program was accelerated through intelligence gathering on the US and German nuclear weapon programs. Espionage coups, especially via Klaus Fuchs and David Greenglass, included detailed descriptions of the implosion-type Fat Man bomb and plutonium production. In the final months of the war, the Soviet "Russian Alsos" task force competed against the Western Allies' Alsos Mission to capture German and Austrian nuclear scientists and material, including refined uranium and cyclotrons. The Soviet project utilized East German industry for further uranium mining, refinement, and instrument manufacture. Lavrentiy Beria was placed in charge of the atomic project, and the replication of the Fat Man bomb was prioritized. The Manhattan Project had established a monopoly on the global uranium market. The Soviet project relied on SAG Wismut in East Germany and the development of the Taboshar mine in Tajikistan. Domestic large-scale production of high purity graphite and high purity uranium metal, to construct plutonium production reactors, was a significant challenge. In late 1946, F-1, the first nuclear reactor outside North America, achieved criticality at Laboratory No. 2. In mid-1948, the A-1 plutonium production reactor became operational at the Mayak site, and in mid-1949, the first plutonium metal was separated. The first nuclear weapon was assembled at the KB-11 design...