Before the second world war some important investigations in nuclear physics led to the discovery of the nuclear fission of heavy nuclei.
The first proven nuclear fission was performed by Otto Hahn Otto Hahn in Germany in 1939.
The political situation in the world during the second world war demanded the rapid development of nuclear weapons technology in the United States.
On 2 December 1942 researchers under the leadership of Enrico Fermi managed to maintain the first controlled nuclear chain reaction in an experimental device called Chicago Pile 1. This was a very huge composite of uranium and graphite. The reaction was maintained for 28 minutes.
PIn the first years after the discovery of the chain reaction, nuclear energy was used only for military purposes. Only after the war was development turned in the direction of the peaceful use of nuclear energy for the production of electricity. In 1946 the Americain Congress passed the very important Atomic Energy Act, which enabled the development of nuclear power for peaceful purposes.
In December 1951 the first four electric bulbs, were illuminated by electricity which was produced by the nuclear reactor EBR-1 in Idaho Falls in the United States. This was the first experimental breeder reactor.
There was a parallel development of the pressurized water reactor, which was first designed for the propulsion of submarines. It was successfully tested in 1953. The first nuclear submarines were the Nautilus and Seawolf.
In the 1954 in Obninsk in the Soviet Union the first nuclear power plant in the world was successfully started: APS-1. It produced only 5 MW of electric power. It was graphite moderated and marks the beginning of the later RBMK type reactors.
On 17 July 1955 the experimental boiling reactor produced for the first time enough electricity to illuminate the city of Arco in Idaho, United States.
On 17 October 1956 the first gas-cooled nuclear power plant was started in Calder Hall in Great Britain. This was the beginning of the British nuclear programme.
In 1956 the first commercial nuclear power plant, Shippingport in the USA was started. The second one, Yankee-Rowe was built in 1960 in Massachusetts. They both used pressurized water reactors and were constructed by Westinghouse.
In 1960 the General Electric company started the first commecial boiling water nuclear power plant, Dresden near Chicago in the United States of America.
In 1962 the first Canadian nuclear power plant, NPD was started. It used natural uranium and heavy water.
The first nuclear power plant in France was built under American licence in 1965.
The first power plants started the era of commercial use of the nuclear fission for the production of electricity.