Chicago Pile-1 final uranium slugs. Chicago Pile-1 Chicago Pile-1 (CP-1) was the world's first nuclear reactor. On 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated in CP-1, during an experiment led by Enrico Fermi. The reactor's development was part of the Manhattan Project, the Allied effort to create atomic bombs during World War II. It was built by the Metallurgical Laboratory at the University of Chicago, under the west viewing stands of the original Stagg Field. Fermi described the apparatus as "a crude pile of black bricks and wooden timbers". The reactor was assembled in November 1942, by
Enrico Fermi a workable design: a pile of uranium oxide blocks interspersed with graphite bricks. Szilárd, Anderson, and Fermi published a paper on "Neutron Production in Uranium". But their work habits and personalities were different, and Fermi had trouble working with Szilárd. Fermi was among the first to warn military leaders about the potential impact of nuclear energy, giving a lecture on the subject at the Navy Department on 18 March 1939. The response fell short of what he had hoped for, although the Navy agreed to provide $1,500 towards further research at Columbia. Later that year, Szilárd, Eugene Wigner, and Edward