The Atomic Energy Commission (AEC) was a United States government agency established in 1946 to oversee the development of nuclear energy. The AEC was headed by a chairman, who was appointed by the President and confirmed by the Senate. The AEC was responsible for the regulation of nuclear power plants, research into nuclear weapons, and the promotion of peaceful uses of nuclear technology. The AEC was replaced by the Nuclear Regulatory Commission in 1975. The Representative on the AEC was REP, and the Chairman from 1949-1953 was Lewis L. Strauss, who was succeeded by Gordon Dean in 1953. Dean was succeeded by Thomas E. Knapp in 1955.