Inaugural Soviet Nuclear Test - Multilateral Dialogue Vienna

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August 1949 29

Inaugural Soviet Nuclear Test

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CTBTO, Public domain

RDS-1, the first of 456 Soviet nuclear tests at the Semipalatinsk test site

On 29 August 1949, the Soviet Union tested its first plutonium implosion nuclear device named ‘RDS-1’ on the Semipalatinsk test site (‘polygon’) in Kazakhstan. The estimated yield of the explosion was 22 kilotons.

The Soviet nuclear program started with the establishment of the Uranium Commission of the USSR Academy of Sciences in 1940. In 1943, the State Defense Committee charged the People’s Commissariat for Nonferrous Metals with uranium production. The same year physicist Igor Kurchatov became the head of Laboratory #2, which coordinated all nuclear research in the USSR. The laboratory’s alias was ‘Laboratory of Measuring Instruments of the Academy of Sciences.’ On 20 August 1945, Lavrentiy Beria became a head of a specially created sub-committee of the State Defense Committee. The sub-committee supervised all work on the use of the intra-atomic energy of uranium.

The Soviet Union also had its limited-access nuclear cities: in April 1946, the city of Sarov became the design bureau (KB-11) – the country's first centre for the development and creation of nuclear weapons, which became both an experimental and theoretical base (subsequently – the All-Union Scientific Research Institute of Experimental Physics [VNIIEF], now – the Russian Nuclear Center).

Why It Matters

Similarities between the Soviet RDS-1 and the weapons used in the US Trinity test were no coincidence. The physicist Klaus Fuchs, who was a part of the Manhattan Project and worked on the first US bombs at Los Alamos, spied for for the Soviets providing extensive information on the project. The Soviet RDS-1 closely resembled the US plutonium fueled ‘Fat Man.’

The test of RDS-1 known as ‘First Lightning’ in the USSR, and ‘Joe-1’ in the US, caught Western Powers by surprise and inaugurated the cold war nuclear arms race, as well as leading to development of the much more powerful ‘hydrogen bomb. The initial Soviet atomic bomb were developed in two versions: "heavy fuel" (plutonium, RDS-1) and "light fuel" (uranium-235, RDS-2).