Enrico Fermi and moved to the Argonne Woods site. There Fermi directed experiments on nuclear reactions, revelling in the opportunities provided by the reactor's abundant production of free neutrons. The laboratory soon branched out from physics and engineering into using the reactor for biological and medical research. Initially, Argonne was run by Fermi as part of the University of Chicago, but it became a separate entity with Fermi as its director in May 1944. When the air-cooled X-10 Graphite Reactor at Oak Ridge went critical on 4 November 1943, Fermi was on hand just in case something went wrong. The technicians woke
Experimental Breeder Reactor I 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 (see also the Clementine nuclear reactor). 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.