Experimental Breeder Reactor I

Experimental Breeder Reactor No. 1
U.S. National Register of Historic Places
U.S. National Historic Landmark
Experimental Breeder Reactor Number 1 in Idaho, the first power reactor
Show map of Idaho Show map of the United States
Location	Butte County, Idaho, US
Nearest city	Arco, Idaho
Coordinates	43°30′41″N 113°00′23″W / 43.51132°N 113.0064°W / 43.51132; -113.0064
Built	1950
Architect	Atomic Energy Commission
NRHP reference No.	66000307
Significant dates
Added to NRHP	October 15, 1966[1]
Designated NHL	December 21, 1965[2]

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.^[3] 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 illuminate four 200-watt light bulbs.^[4][5] EBR-I subsequently generated sufficient electricity to power its building, and continued to be used for experimental purposes until it was decommissioned in 1964. The museum is open for visitors from late May until early September.^{[citation needed]}