This drawing depicts the historic event on Dec. 2, 1942, when a group of 49 scientists led by Enrico Fermi created the world's first controlled, self-sustaining nuclear chain reaction underneath the University of Chicago's Stagg Field football stadium.
Some of those present would later founded Argonne National Laboratory. Called Chicago Pile 1 (CP-1), the reactor was the first in a distinguished series of "Chicago Pile" reactors that advanced nuclear reactor technology, helped commercialize it for electricity generation, and developed the early use of nuclear reactors as a source of neutrons for research in other scientific disciplines. The other Chicago Pile reactors were:
• Chicago Pile 2 – CP-1 was disassembled in February 1943 and rebuilt the following month as Chicago Pile 2 in a slightly different configuration in a Palos Park, Ill., forest preserve. The site would later become Argonne National Laboratory. A small laboratory atop the 14,000-ton reactor provided space for limited experiments using neutrons from the reactor's core. The reactor's face contained ports through which materials could be inserted into the core for irradiation.
• Chicago Pile 3 – Chicago Pile 3 was the world's first "heavy-water moderated" reactor. It was designed by Eugene Wigner; at Enrico Fermi's request, Walter Zinn directed its construction in the Argonne Lab in 1943. Chicago Pile 3 achieved criticality in 1944. Research programs conducted at CP-3 included reactor physics studies, fission product separations, tritium recovery from irradiated lithium, and studies of radionuclide metabolism in laboratory animals.
• Chicago Pile 4 was the original name for Experimental Breeder Reactor-I (EBR-I), the first liquid-metal-cooled fast reactor. Designed, built and operated by Argonne National Laboratory, EBR-I was the first reactor built on the National Reactor Testing Station in Idaho. EBR-I's primary mission was to develop and test the concept of a nuclear breeder reactor. It was the first nuclear reactor to produce useful amounts of electricity, to demonstrate the breeding of plutonium from uranium and to produce electricity with a plutonium core.
• Chicago Pile 5 – From 1954 to 1979, Argonne's Chicago Pile 5 reactor was a research workhorse, providing neutrons for experiments on the structure and behavior of materials. It started operation in 1954 and was used until 1979. Technicians for Illinois’ first commercial power plants were trained at CP-5.