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President Truman signs the Atomic Energy Act, creating the Atomic Energy Commission, August 1, 1946. Senator Brien McMahon is second from right.CIVILIAN CONTROL OF ATOMIC ENERGY
Events > Postscript -- The Nuclear Age, 1945-Present

While negotiations on international control of the atom went nowhere and deteriorating relations between the United States and the Soviet Union ushered in the Cold War, a domestic debate took place over the long-term management of America's nuclear program.  As they did with international control, Vannevar Bush and James B. Conant took the initial lead.  In September 1944, they proposed to Secretary of War Henry L. Stimson setting up postwar a civilian twelve-member atomic energy commission, with four members representing the military services, that would control not only large-scale production but also research involving minute amounts of material.

Vannevar Bush and James Conant, Berkeley, 1940The issue of domestic control remained largely dormant until July 1945 when the Interim Committee considered a draft atomic energy bill prepared by two War Department lawyers, Brigadier General Kenneth C. Royall and William L. Marbury.  Following the basic outline of Bush's and Conant's proposal, the draft legislation established a part-time, nine-member commission with responsibilities very similar to those of the Manhattan Project.  The legislation in comparison to the Bush-Conant plan provided for an even stronger military presence, with again four representatives from the military services on a smaller-sized commission.  Similar as it was to their own proposal, Bush and Conant now believed, as the war was coming to a close, that only civilians should serve on the commission.  They also thought that excessive power was being granted to a peacetime organization.  Royall and Marbury made modest revisions to the draft legislation, but these did not fundamentally alter the level of military control and government dominance in atomic activities.

J. Robert Oppenheimer, Enrico Fermi, and Ernest LawrenceFollowing Hiroshima and Nagasaki, the War Department pushed forward with the draft legislation.  After affected federal agencies approved, President Harry S. Truman advocated speedy passage of the congressional version of the bill, the May-Johnson bill, in his October 3 special address to Congress on atomic energy.  General Leslie Groves, as well as Bush and Conant, testified at hearings in the House of Representatives that the sweeping powers granted the proposed commission were necessary and that only government control of atomic power could prevent its misuse.  Although Ernest Lawrence, Enrico Fermi, Robert Oppenheimer, and some of the other lead scientists had certain misgivings, they also regarded the bill as acceptable.  Many of the scientists at the Met Lab and at Oak Ridge, however, were not so sure.  They complained that the bill was objectionable because it was designed to maintain military control over nuclear research, a situation that had been tolerable during the war but was unacceptable during peacetime when free scientific interchange should be resumed.  Particularly onerous to the scientific opponents were the proposed penalties for security violations contained in the May-Johnson bill - ten years in prison and a $100,000 fine.  Organized scientific opposition in Washington slowed the progress of the bill and ultimately doomed it.  A growing coalition of scientists, government officials, and legislators came out in opposition to the May-Johnson bill, and Truman privately withdrew his support but did not offer a substitute.

Senator Brien McMahonCivilian versus military control had become the core issue in the legislative battle over atomic energy.  On December 20, Brien McMahon, freshman Democratic senator from Connecticut who two months earlier had successfully created and became chair of the Senate's Special Committee on Atomic Energy, introduced a substitute to the May-Johnson bill.  His bill, which called for five civilian commissioners and gave the commission strict control over the production of fissionable material and the fabrication and stockpiling of weapons, essentially excluded the military.  Hearings on the new McMahon bill began in late January 1946.  Groves and Secretary of War Robert P. Patterson opposed McMahon's bill, citing weak security provisions and the low military presence.  Groves also disliked the stipulation that commission members be full time (he thought that more eminent commissioners could be obtained if work was part-time), and he objected to the bill's provision that atomic weapons be held in civilian rather than military custody.  These arguments were not without effect.  Although few in Congress advocated military control, most did not want the military totally excluded from atomic energy matters.  As a result, the McMahon bill, over the next several months, underwent considerable revision.  The Senate approved the bill on June 1, and the House approved it on July 20, with a subsequent conference committee eliminating most substantive amendments added by the House.  President Truman signed the McMahon Act, known officially as the Atomic Energy Act of 1946, on August 1.

AEC SealThe sometimes bitter debate between those who advocated continued military stewardship of the nation's arsenal and those who saw continued military control as inimical to American traditions ended in victory for civilian authority but with considerable ongoing military influence.  Under the terms of the 1946 act, the Army's responsibilities for the nation's atomic energy program transferred to a civilian agency, the United States Atomic Energy Commission (AEC).  The act called for a commission consisting of five full-time, civilian presidential appointees, serving staggered five-year terms, and a general manager who administered day-to-day operations.  The act mandated four operational divisions: research, production, engineering, and military application, with the director of the division of military application required to be a member of the armed forces.  Under the act, the commission was to be the "exclusive owner" of production facilities but could let contracts to operate them.  This meant the commission could, if it so desired, continue the system of contractor operation initiated by the Manhattan Engineer District.  The commission was to take possession as well of "all atomic weapons and parts thereof" but, unlike in the original McMahon bill, the act contained the provision that the President "from time to time" may direct the commission to deliver "weapons to the armed forces for such use as he deems necessary in The Institutional Origins of the Department of Energythe interest of national defense." The act also created a General Advisory Committee and a Military Liaison Committee.  The General Advisory Committee, consisting of nine presidential appointees, was to provide assistance and advice to the commission on scientific and technical issues.  The Military Liaison Committee, consisting of representatives of the War and Navy Departments, was to provide for input by defense officials.  Finally, the act established in Congress a Joint Committee on Atomic Energy (JCAE) composed of nine members each from the Senate and House of Representatives to oversee atomic affairs.

Manhattan Project assets transferred to the Atomic Energy Commission at midnight, December 31, 1946.  The AEC exercised governmental control over military, regulatory, and developmental aspects of the atom until 1975 when the agency was disestablished.  In its place, Congress created the Nuclear Regulatory Commission to oversee the nuclear power industry and other civilian uses and the Energy Research and Development Administration (ERDA) to coordinate energy development including nuclear power.  The AEC's weapons program was folded into ERDA.  In 1977, ERDA and the energy programs from a number of other agencies were brought into the new Department of Energy.

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Sources and notes for this page.

The text for this page was adapted from, and portions were taken directly from the Office of History and Heritage Resources publications: F. G. Gosling, The Manhattan Project: Making the Atomic Bomb (DOE/MA-0001; Washington: History Division, Department of Energy, January 1999), 57, and Richard G. Hewlett and Oscar E. Anderson, Jr., The New World, 1939-1946: Volume I, A History of the United States Atomic Energy Commission (Washington: U.S. Atomic Energy Commission, 1972), 408-416, 421-455, 482-530.  Also used was Vincent C. Jones, Manhattan: The Army and the Atomic Bomb (Washington, D.C.: U.S. Government Printing Office, 1985), 568-569, 574-578.  The McMahon bill is reprinted in Hewlett and Anderson, The New World, 714-722.  The photograph of President Harry Truman signing the Atomic Energy Act (including the close-up of Senator Brien McMahon) is courtesy the Department of Energy (DOE).  Click here for more information on the photograph of Vannevar Bush and James Conant.  The photograph of Robert Oppenheimer, Enrico Fermi, and Ernest Lawrence is courtesy the Lawrence Berkeley National Laboratory.  The AEC seal and the DOE family tree are courtesy DOE.

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