Signed into law on August 1, 1946, by President HARRY TRUMAN, the Atomic Energy Act (also known as the McMahon Act, after its sponsor, Senator Brien McMahon [D-Conn.]) established a civilian Atomic Energy Commission (AEC) to develop and control the use of atomic energy in the United States. Quite controversial in its management of nuclear weapons testing and nuclear power development, the AEC operated from 1947 until 1974.

In the early 1970s, the AEC faced increasing opposition from politicians and the larger public, who were critical of its regulatory duties, especially to those responsibilities pertaining to the setting of radiation protection standards, reactor safety, and protection of the environment. In 1974, CONGRESS reorganized and split the AEC into the Energy and Research Development Administration and the Nuclear Regulatory Commission. Although the AEC was successful in promoting nuclear power and building the nation's nuclear arsenal, it has also been responsible for some of the most egregious cases of environmental contamination in the history of the United States.

The Atomic Energy Act conferred extraordinary power on the AEC to develop, produce, and control the use of atomic energy for both military and civilian use. The AEC owned all production facilities and reactors and controlled all technical and scientific research produced in its laboratories. The AEC thus possessed a national nuclear monopoly. Although the act transferred control of the U.S. Army's MANHATTAN PROJECT to the civilian Atomic Energy Commission on January 1, 1947, the organization of the commission reflected its broad mandate to develop both civilian and military uses of atomic energy. The AEC was composed of five commissioners, a general manager appointed by the president, and three advisory committees: the Congressional Joint Committee on Atomic Energy, the General Advisory Committee, and the Military Liaison Committee. Given the increasing antagonism between the United States and the Soviet Union in the late 1940s, however, military imperatives increasingly consumed the commission's time and resources.

The organization of the national laboratories inherited from the Manhattan Project—including Los Alamos National Laboratory in New Mexico and Oak Ridge National Laboratory in Tennessee—reflected the commission's dual mandate as well. Operated by independent contractors (usually universities), the laboratory system adhered to national security measures such as security clearances, compartmentalization, and classification. Yet, the labs also mimicked the open atmosphere and free exchange of scientific ideas common to universities by permitting interlaboratory conferences and exchanges. Each laboratory ostensibly engaged in both pure research and military-driven applied research. In reality, however, COLD WAR imperatives drove the content and direction of much of the research at the laboratories, even when not directly related to military matters.

One of the top goals of the AEC in the late 1940s was to expand and develop the national nuclear arsenal. Although the United States held a nuclear monopoly at the time, the AEC stepped up production of plutonium at the Hanford Site in Washington State and of uranium 235 at Oak Ridge, Tennessee. Similarly to the laboratory system, independent contractors (usually corporations) operated the production facilities. In 1948, the AEC began testing new weapons designs at the Pacific Proving Grounds in the Marshall Islands in the Pacific Ocean.

The detonation of the first Soviet atomic bomb (Joe-1) in August 1949 and the outbreak of the KOREAN WAR the following summer intensified demands for atomic weapons development and production. Following President Truman's order to begin a crash-test program to develop a thermonuclear hydrogen bomb in early 1951, the AEC embarked on a vast expansion program to produce lithium 6 and tritium at various sites including Oak Ridge and the Savannah River. The intensification of Cold War hostilities also suggested the need for a continental nuclear proving ground, leading to the establishment of the Nevada Proving Grounds (later the Nevada Test Site) 75 miles northwest of LAS VEGAS, NEVADA. Page 147  |  Top of ArticleThe AEC detonated its first thermonuclear fusion bomb (code-named Mike) in fall 1952 in the Pacific. The resulting 10.4-megaton blast was 450 times more powerful than the fission bomb detonated over Nagasaki, Japan, on August 9, 1945, which helped end WORLD WAR II.

By the mid-1950s, the AEC had largely met the military demand for fissile materials. President DWIGHT EISENHOWER turned the attention of the commission toward the development of nuclear reactors for civilian and military uses. After Eisenhower's Atoms for Peace speech to the UNITED NATIONS General Assembly in 1953, the U.S. Congress revised the Atomic Energy Act to empower the commission to share technical and scientific information with foreign governments and to promote public and private atomic energy development. The resulting Atomic Energy Act of 1954 facilitated private investment in the development of nuclear reactors for power generation and broadened the commission's initial focus on weapons production to include reactor development as well.

Eisenhower's attempts to emphasize the more benign aspects of nuclear technology were shattered, however, by the controversy over nuclear fallout resulting from the 1954 Castle Bravo thermonuclear test in the Pacific. The test spread considerable radioactive fallout throughout the South Pacific islands, and one Japanese fisherman died. The incident alerted the global public to the environmental dangers of worldwide radioactive contamination from fallout. Much of the focus of the controversy centered on the long-term health hazards posed by prolonged exposure to STRONTIUM 90 (a radioactive by-product of fission) that assimilated into the food chain. Concern over the AEC's role as both regulator and promoter of atomic energy eroded the public trust in the commission's ability to assure adequate safety during weapons tests. The fallout controversy prompted Eisenhower to propose a nuclear testing moratorium in 1958. He also oversaw the creation of a presidential Federal Radiation Council to assuage public fears over the commission's dual and contradictory roles. In 1963, after the Cuban missile crisis that nearly sparked a nuclear war in October 1962, the Soviet Union and the United States signed the Nuclear Test Ban Treaty, which ended atmospheric, underwater, and outer space tests of nuclear weapons but permitted continued underground testing.

During the 1960s and early 1970s, the AEC continued to devote its resources to ostensibly peaceful projects including the development of thermonuclear weapons for massive earth-moving projects and civilian nuclear reactors for electrical power generation. By the early 1970s, increasing public concern over radiation standards, nuclear reactor safety, and environmental protection led Congress to abolish the agency. To remedy the conflicts inherent in the previous commission's dual mission, Congress divided responsibilities between an Energy Research and Development Administration (later incorporated into the Department of Energy) and a Nuclear Regulatory Commission.

In the late 1970s, the human and ecological toll of the AEC's nuclear production and testing facilities received increasing scrutiny from the public and Congress. Environmental remediation of contaminated AEC facilities, in addition to the testimony of “downwinders,” “atomic veterans,” and Marshall Islanders who claimed that exposure to fallout from the Nevada Test Site and Pacific Proving Grounds detonations resulted in increased illness (primarily cancer) in their communities, badly tarnished the reputation of the weapons testing program and embroiled the U.S. government in a series of lawsuits from litigants seeking compensation throughout the decade and into the 1980s. In 1990, Congress passed the Radiation Exposure Compensation Act (RECO) to compensate individuals in the United States who had diseases due to unintentional exposure to radioactive fallout. A number of former AEC production facilities have been declared SUPERFUND sites, including Hanford Site and Rocky Flats Plant in Denver, Colorado. Cleanup continues today, costing American taxpayers billions in remediation.