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
R4 nuclear reactor R4 nuclear reactor R4 nuclear reactor was a nuclear reactor built at Marviken and the fourth nuclear reactor built in Sweden. It was heavy water moderated and intended for the dual role of 130MWe of power generation as well as plutonium production. It had a central role in the Swedish nuclear weapon programme. During the mid 1960s, the social democratic government officially abandoned the project of designing Swedish nuclear weapons and the Marviken-plant became derelict. It was never loaded with fuel, and the project was cancelled in 1970. The turbine hall was subsequently used for an oil-fired power station, and