70 years ago today, on December 20, 1951, the first Experimental Breeder Reactor (EBR-I, pictured below at left) came online at the Idaho National Laboratory to produce usable electricity through fission. The reactor, initially used to power four 200-watt lightbulbs, was increased to power the whole facility on its second day. While small, the reactor provided scientists with the ability to do a lot of testing. These tests, both successful and unsuccessful, enabled a lot of other reactors, including the EBR-II and coming soon, the Oklo Aurora, to follow with considerable design improvements. In 1966, President Lyndon Johnson declared the EBR-I a National Historic Landmark.
The EBR-I was a liquid metal-cooled fast reactor that used a liquid sodium coolant which transfers heat much better than today’s light water reactors. The second Experimental Breeder Reactor (EBR-II), which operated from 1961 to 1994, ran for more than 30 years quite successfully. However the potential hazards of a sodium leak combined with water was a deterrent to the use of this type of reactor in a submarine. The Navy wanted to have nuclear-powered submarines and opted to use the pressurized light water reactor, that used sea water as its coolant. This choice influenced the later commercial adoption of water cooled reactors on land, even though there were risks associated with the need to replicate an underwater environment to cool the LWRs built on the land.
Which makes the 2020 submission by Oklo to the NRC of a 4th Generation liquid-metal cooled fast reactor not just historic but also somewhat ironic. It’s taken 70 years and a catastrophic climate crisis to finally get back to basics, and reassess the potential of the metallic fuel, liquid-metal collant system that was initially deemed the superior choice for electricity generation on land.
Learn more at the Office of Nuclear Energy’s 9 Notable Facts About the World’s First Nuclear Power Plant – EBR-1, written on June 18, 2019 and posted to the DOE’s ONE Facebook page in honor of the 70th anniversary. Listen to the Boise State Public Radio News report, Idaho experiment that showed nuclear power was more than a weapon turns 70 years old, by Madelyn Beck.