The Soviet Union Tests Its First Atomic Bomb

At seven in the morning on 29 August 1949, the Soviet Union conducted its first nuclear detonation at the Semipalatinsk Test Site in the Kazakh Soviet Socialist Republic. Designated RDS-1, the weapon produced an explosive force equivalent to 22 kilotons of TNT. The successful blast broke the atomic monopoly held by the United States since 1945, altering international diplomacy and initiating a rapid escalation of the nuclear arms race.

Igor Kurchatov served as scientific director of the program, while Yulii Khariton, appointed in 1946, directed the design and assembly of the bomb at a secret weapons laboratory later known as Arzamas-16. The security chief Lavrentiy Beria supervised the overall program, while Mikhail Pervukhin was among the senior officials who oversaw the test itself. Plutonium required for the bomb core was manufactured at the Chelyabinsk-40 industrial complex. Although Soviet scientists had conceptualized a more advanced configuration, Beria insisted on deploying an implosion system with a solid plutonium core closely copied from the American Fat Man model, whose design details had been passed to Moscow by spies inside the Manhattan Project, most notably the physicist Klaus Fuchs.