The Semipalatinsk Test Site (Russian: Семипалатинск-21; Semipalatinsk-21), also known as “The Polygon”, was the primary testing venue for the Soviet Union’s nuclear weapons. It is located on the steppe in northeast Kazakhstan (in the former Kazakh SSR), south of the valley of the Irtysh River. The scientific buildings for the test site were located around 150 km (93 mi) west of the town of Semipalatinsk, later renamed Semey, near the border of East Kazakhstan Region and Pavlodar Region. Most of the nuclear tests taking place at various sites further to the west and the south, some as far as into Karagandy Region.
The Soviet Union conducted 456 nuclear tests at Semipalatinsk from 1949 until 1989 with little regard for their effect on the local people or environment. The full impact of radiation exposure was hidden for many years by Soviet authorities and has only come to light since the test site closed in 1991.According to estimates from Kazakh experts, 1.5 million people were exposed to fallout over the years.
From 1996 to 2012, a secret joint operation of Kazakh, Russian, and American nuclear scientists and engineers secured the waste plutonium in the tunnels of the mountains.
Since its closure on 29 August 1991, the Semipalatinsk Test Site has become the best-researched nuclear testing site in the world, and the only one in the world open to the public year-round.
RDS-1 (Joe 1), 29 August, 1949
The RDS-1 (Russian: РДС-1), also known as Izdeliye 501 (device 501) and First Lightning was the nuclear bomb used in the Soviet Union’s first nuclear weapon test. The United States assigned it the code-name Joe-1, in reference to Joseph Stalin. It was detonated on 29 August 1949 at 7:00 a.m., at the Semipalatinsk Test Site, Kazakh SSR, after top-secret research and development as part of the Soviet atomic bomb project.
RDS-2 (Joe 2), 24 September, 1951
The 2nd Soviet atomic bomb, RDS-2, was tested on September 24, 1951 at the Semipalatinsk test site and produced a 38.3 kiloton yield. It was detonated from the top of a tower 30 meters high.
RDS-3 (Joe 3), OCT 18, 1951
RDS-3 was the third atomic bomb developed by the Soviet Union in 1951, after the famous RDS-1 and RDS-2. It was called Marya in the military. The bomb had a composite design with a plutonium core inside a uranium shell, providing an explosive power of 41.2 kilotons.The RDS-3T was a modernized version and the first mass-produced nuclear weapon by the Soviet Union. It was assigned to Long Range Aviation in 1953.