The Experimental Breeder Reactor-1 was the first facility to produce electricity generated by nuclear energy.
The Experimental Breeder Reactor - 1 (EBR-1) is located at the Idaho National Laboratory in Idaho Falls, Idaho. On December 20, 1951, the EBR-1 produced the first usable electricity generated by atomic energy . From the next day until it was decommissioned in 1963, the EBR-1 supplied all of the power for its own building. The EBR-1 operated for 12 years before shutting down in December 1963. Three years after it was decommissioned, President Johnson dedicated the facility as a registered National Historic Landmark. The nearby city of Arco, Idaho became the first city in the world to be lit by nuclear power.
The first production of usable nuclear electricity occurred on December 20, 1951, when four light bulbs were lit with electricity generated from the EBR-1 reactor
More information on the EBR-1