The world's first man-made nuclear reactor (nuclear reactor) was called Chicago Pile 1 (CP-1) and was designed by Italian-American physicist Enrico Fermi. On December 2, 1942, the first man-made nuclear reactor was installed in Chicago, Illinois, USA.

From that day on, the reactor will automatically trigger a nuclear chain reaction. The CP-1 nuclear reactor was originally built for research purposes. It ran from 1942 to 1943. Uses natural uranium as fuel.

The University of Chicago's Manhattan Project CP-1 nuclear reactor was used.