Experimental Breeder Reactor-II (EBR-II) is a reactor designed, built and operated by Argonne National Laboratory in Idaho. It was shut down in 1994. Custody of the reactor was transferred to Idaho National Laboratory after its founding in 2005.
It is a sodium cooled reactor with a thermal power rating of 62.5 megawatts (MW), an intermediate closed loop of secondary sodium, and a steam plant that produces 19 MW of electrical power through a conventional turbine generator. The original emphasis in the design and operation of EBR-II was to demonstrate a complete breeder-reactor power plant with on-site reprocessing of metallic fuel. The demonstration was successfully carried out from 1964 to 1969. The emphasis was then shifted to testing fuels and materials for future, larger, liquid metal reactors in the radiation environment of the EBR-II reactor core. It operated as the Integral Fast Reactor prototype. Costing more than US$32 million, it achieved first criticality in 1965 and ran for 30 years. It was designed to produce about 62.5 megawatts of heat and 20 megawatts of electricity, which was achieved in September 1969 and continued for most of its lifetime. Over its lifetime it has generated over two billion kilowatt-hours of electricity, providing a majority of the electricity and also heat to the facilities of the Argonne National Laboratory-West.
Curiously it does not mention that thorium was its fuel, this thing also eats nuclear waste stockpiles and leaves a whole lot less spent fuel, of lower halflife!