When Was the First Nuclear Power Plant Built?

By Contributing Writer; Updated April 24, 2017
Nuclear Power Plants History

Nuclear power plants, once hailed as a miracle of technology, have been around since the mid 1950s, when they began sprouting up in countries like Russia, Great Britain and the United States.

Time Frame

The first time a nuclear reactor generated power was on Dec. 20, 1951, near Arco, Idaho. This experimental reactor produced around 100kW of power and was also the first reactor to have a partial meltdown in 1955.


The first actual nuclear power plant cranked up its generators on June 27, 1954.


It was in Obninsk near Moscow in Russia that the first nuclear power plant began generation of electricity for a power grid. This government-owned plant produced about 5 megawatts (MW).


The world's first privately owned commercial power plant opened in 1956 in Sellafield, England. It was called Calder Hall and produced 50 MW of power initially and later 200.


Shippingport, Pennsylvania, was the location of the first commercial nuclear reactor in the United States. The Shippingport Reactor went on line in December 1957.