Experimental Breeder Reactor I (EBR-I) is a decommissioned research reactor and U.S. National Historic Landmark located in the desert about 18 miles (29 km) southeast of Arco, Idaho.It was the world's first breeder reactor. At 1:50 p.m. on December 20, 1951, it became one of the world's first electricity-generating nuclear power plants when it produced sufficient electricity to …

Experimental Breeder Reactor-II (EBR-II) is a sodium-cooled fast reactor designed, built and operated by Argonne National Laboratory at the National Reactor Testing Station in Idaho. It was shut down in 1994. Custody of the reactor was transferred to Idaho National Laboratory after its founding in 2005.. Initial operations began in July 1964 and it achieved criticality in 1965 at a …