As part of the National Reactor Testing Station, EBR-I's construction started in late 1949. The reactor was designed and constructed by a team led by Walter Zinn at the Argonne National Laboratory Idaho site, known as Argonne-West. In its early stages, the reactor plant was referred to as Chicago Pile 4 and Zinn's Infernal Pile. Installation of the reactor at EBR-I took place in early 1951 and it began power operation on August 24, 1951. On December 20 of that year, atomic energy was successfully harvested at EBR-1 for the first time. The following day, the reactor produced enough power to light the whole building. The power plant produced 200 kW of electricity out of 1.4 MW of heat generated by the reactor. The design purpose of EBR-I was not to produce electricity but instead to validate nuclear physics theory that suggested that a breeder reactor should be possible. In 1953, experiments revealed the reactor was producing additional fuel during fission, thus confirming the hypothesis. On November 29, 1955, the reactor at EBR-I suffered a partial meltdown during a coolant flow test. The flow test was trying to determine the cause of unexpected reactor responses to changes in coolant flow. It was subsequently repaired for further experiments, which determined that thermal expansion of the fuel rods and the thick plates supporting the fuel rods was the cause of the unexpected reactor response. Although EBR-I produced the first electricity available in-house, a nearby experimental boiling water reactor plant called BORAX-III was connected to external loads, powering the nearby city of Arco, Idaho in 1955, the first time a city had been powered solely by nuclear power. Besides generating the world's first electricity from atomic energy, EBR-I was also the world's first breeder reactor and the first to use plutonium fuel to generate electricity. EBR-1's initial purpose was to prove Enrico Fermi's fuel breeding principle, a principle that showed a nuclear reactor producing more fuel atoms than consumed. Along with generating electricity, EBR-1 would also prove this principle.
EBR-I was deactivated by Argonne in 1964 and replaced with a new reactor, Experimental Breeder Reactor II. It was declared a National Historic Landmark in 1965 with its dedication ceremony held on August 25, 1966, led by President Lyndon Johnson and Glenn T. Seaborg. It was also declared an IEEE Milestone in 2004.
In 2019 Dr. Catherine Riddle, a scientist at the Idaho National Laboratory submitted a model of the EBR-1 reactor to Lego for the Lego Ideas Project in the hopes it will become a real Lego model kit. The campaign is still active and collecting votes.
