Oak Ridge
Oak Ridge Nuclear Complex - Graphite Reactor

Oak Ridge

Over the years, “the Government” had come to East Tennessee in many forms, varying from the Civil War Confederacy to the Tennessee Valley Authority of the 1930s, but the most dramatic and least public incursion followed quickly on the heels of the Great Depression during the Second World War. Government officials, most of them wearing the uniform of the U.S. Army and the insignia of the Corps of Engineers, arrived quietly in the summer of 1942 to observe, study, consult maps, and leave. They were followed, more ominously, by men with surveyor’s stakes.

The nation had been at war with Japan, Germany, and Italy since the preceding December. Even prior to the nation’s military involvement, President Franklin D. Roosevelt had been informed of an unexpected and serious potential danger by concerned scientists. In 1939 Leo Szillard and Eugene P. Wigner persuaded Albert Einstein to sign a letter warning Roosevelt of the possibility that Adolph Hitler’s Nazi Germany could construct a revolutionary weapon through atomic fission capable of creating vast amounts of explosive power. Heeding the warning, Roosevelt began a tentative exploration of the possibilities of constructing an atomic bomb. But only after Pearl Harbor and the American entry into the war was the project pursued with urgency.

That urgency brought newly promoted Brigadier General Leslie R. Groves to East Tennessee in September 1942. He had been appointed to head the recently created Manhattan Engineer District, or, more commonly, the Manhattan Project. His task was to supervise the location, planning, and construction of whatever facilities were necessary to construct an atomic bomb before the Germans could do it.

This remote area of East Tennessee seemed to meet many of the requirements for the main work site. Approximately one thousand families, roughly four thousand people, lived in the area of primary interest to the government planners. Mostly farmers, the residents were clustered around small crossroads centers with names like Wheat, Elza, Scarboro, and Robertsville. Moving them would not present a large problem for the army.

Some of the planned processes would require vast amounts of electricity, which the TVA could provide. There was an abundance of clean water, a good rail line, adequate roads, and the land could be acquired cheaply. Topographically, the reservation was a long valley divided into smaller segments by ridges. This meant that the individual processing plants could be separated geographically, so that if, in an unforeseen disaster, one blew up, the others would not explode like firecrackers on a string. The town itself was sited on the eastern end of the reservation, away from the plants.

Land acquisition began quickly. In the fall of 1942 residents were informed, sometimes simply by notices nailed to their front fence posts, that they would have to leave; the government was taking their land. A year later, the eviction process was complete. Although most of the former residents accepted the government offers for their land, a few brought legal action challenging the valuations. Roane County lost approximately one-eighth of its land area to the project, but the focus of the project was east, toward Clinton and Knoxville, rather than south and west, toward Kingston and Harriman, and Anderson County was more directly affected by the government’s activities. Oak Ridge, the town created by the project, was only eight miles from Clinton, the seat of Anderson County, which gave up one-seventh of its land to the project. State Highway 61, which had run directly through the reservation site, was closed and rerouted to the north, through Motlow. The reservation site was approximately seventeen miles long, averaging seven miles in width, and encompassing some 59,000 acres.

Providing security for a project of such scope and purpose involved intense planning. The Clinch River surrounded the reservation on three sides, providing a natural defense. On the exposed northern side, the army erected a fence, which was patrolled by armed guards. Knoxville, a city of 110,000 people who provided the labor base for the construction and support work force, was thirty miles away, isolating the work site from the outside world. As a further measure of security, the site was provided with an ambiguous title, the Clinton Engineering Works (CEW). All personnel entering the site were required to have a pass and a purpose. On the site itself, army security personnel tried to separate scientists and engineers associated with the various segments of the project to prevent them from discussing their work with one another. Of course, these efforts extended to outside contacts as well. A passion for secrecy dominated the early years of the community and extended into the tension-filled era of the Cold War, marking Oak Ridge with a concern for security unique among Tennessee cities in the five decades following World War II.

The town was an adjunct to the plants. Built as well as possible in order to keep the gathering scientific and engineering personnel reasonably content, the town was planned by the prominent firm of Skidmore, Owings, and Merrill, who designed plans to house eight thousand people. The town was laid out along the south side of Black Oak Ridge, with Outer Drive at the top and Tennessee Avenue and Oak Ridge Turnpike running parallel, east to west, along the bottom of the ridge. Avenues, named for the states and arranged alphabetically north to south, connected the east-west thoroughfares. Courts, roads, and lanes branching off the avenues received names beginning with the same first letter. For example, all the streets off Delaware Avenue began with the letter “D.” The simplified arrangement proved to be a great boon in a community where everyone was a newcomer.

The nearly insatiable demands of the project for additional workers placed planners and contractors in the position of constantly attempting to catch up and constantly failing in their efforts. The well-planned family homes, “cemestoes” (bonded cement and asbestos), were supplemented by apartments and by dormitories for single workers. But they were also quickly overwhelmed, and more temporary housing of limited livability including trailers, barracks, hutments, plywood Flat Tops, and “Victory Cottages” sprang up along the ridge and spread into the valley.

Recruitment of scientific talent took a variety of forms, including personal contacts among the members of the nation’s leading academic and scientific institutions. Foreign scholars, forced out of Italy, Germany, and Eastern Europe by the Fascists and Nazis, added to the pool. Scientifically trained personnel drafted into the ranks of the army were assigned to the Special Engineer Detachment (SED), often before recruits had had much more than the basics of basic training, a situation that developed them into a creative, but often quite unmilitary unit. The Corps of Engineers, of course, made up the major part of the military presence, but, later in the war, two companies of WACs expanded the number of uniformed personnel.

At the heart of the scientific and engineering effort were the facilities designed as X-10, Y-12, and K-25. Stone and Webster Corporation was the primary contractor for these facilities. Oak Ridge would serve as the headquarters for the entire national project, house a graphite reactor, and provide facilities for separating the fissionable isotope uranium 235 from the much more plentiful U-238.

Construction for X-10 and the graphite reactor began in February 1943. It would serve as a pilot plant for creating a new, fissionable element, plutonium, and separating it chemically. Larger quantities of plutonium would be produced at the Hanford site in eastern Washington. During the war, X-10 was built and operated by a combination of contractors which included Du Pont, the Metallurgical Laboratory of the University of Chicago, and Monsanto Chemical Corporation. After the war it was designated as Oak Ridge National Laboratory (ORNL) and served as a laboratory for nuclear research, leading the nation in research in nuclear power and nuclear medicine. After 1948 supervision was transferred to Union Carbide’s Nuclear Division. “The Lab” continues to conduct basic research in physics and other sciences and produces radioactive isotopes with many uses in science and industry.

Since it was not certain in 1942 which method of separating U-235 would yield the quickest and richest result, the original plan was to pursue as many methods as seemed feasible. Y-12, operated by Tennessee Eastman Corporation, used an electromagnetic separation process. After the war Y-12 was operated by Union Carbide and was primarily responsible for shaping nuclear components for weapons. The K-25 plant, operated from the beginning by Union Carbide Corporation, used a very different gaseous diffusion process where highly corrosive uranium hexaflouride gas was passed repeatedly through membranes, allowing the slightly lighter U-235 isotopes to be gradually concentrated. Construction on Y-12 was begun in the spring of 1943, and K-25 was built in the fall. A third process, S-50, using thermal diffusion was begun too late to have any impact on events and was not carried to completion.

The scientists and engineers gathered together at Oak Ridge, nearly all of them very young, found themselves working terribly long hours on some of the most exciting work many of them would ever do. Repeatedly, they demonstrated that what conventional wisdom said could not be done could, in fact, be accomplished in less time than anyone thought possible. During and after the war, Oak Ridgers provided much of the theoretical and practical grounding for the developing nuclear industry.

Beginning with the arrival of construction workers in spring 1943, Oak Ridge had grown to an astounding 66,000 residents by the summer of 1944, before peaking at a population of 75,000 by the summer of 1945. The reservation demanded a work force of 80,000. In 1944 the two-year-old town was the fifth largest city in Tennessee with the sixth largest bus operation in the nation. Many of those who worked but did not live in Oak Ridge were bused in, some from distances of more than fifty miles. Some who lived off the reservation commuted by car, but wartime shortages of tires and gasoline limited automobile use. The right to live in Oak Ridge depended on employment there, while housing itself was designated by worker position and family size.

The original design of the town included an area in the eastern section designated as the “Negro Village,” with dormitories and some well-built homes. However, the operating companies did not hire African Americans in positions that qualified them for that type of housing, and the Negro Village was quickly absorbed into the larger white community. African American employees lived in hutments further west that were segregated both by race and by gender. The Oak Ridge community, as was the case in government projects throughout the nation, complied with local custom in racial matters, and Tennessee was, by law and custom, a segregated state in the 1940s. However, the practice of segregation met some local resistance, and in 1955 Oak Ridge became one of the first cities in the South to mandate desegregation of its public schools.

Tensions between those who came to Oak Ridge and those who gave up the land for the facilities or who lived in close conjunction with the reservation became apparent during the war and continued to some extent after 1945. Those who had lived prior to 1942 in what was to become Oak Ridge had identified closely with the land where their families had lived and farmed, often for generations. Some who had been forced off their land harbored resentment for many years. The newcomers had no roots in Tennessee and viewed themselves as temporary residents. The majority of the new residents were young and filled with the camaraderie fostered by work on a project they felt certain would win the war. In addition to the young and enthusiastic outsiders who had little in common with traditional area residents, the project absorbed large numbers of local workers attracted by high wages, excitement, and patriotism. The competition for scarce labor did little to foster good relations with outside employers, especially as it extended beyond the demand for construction and laboratory personnel. In order to educate the children of Oak Ridge employees, the city demanded the best teachers available and paid significantly more than surrounding school districts to get them. The high standard of education produced in Oak Ridge became a source of pride for the city’s residents, but the loss of teaching staff and the higher wages bred resentment in school districts outside the fence. Many viewed Oak Ridge as a highly secret, probably wasteful, and certainly enormous federal project. In an era of war-generated shortages, fears, and discontent, it was easy to blame the project and the people living and working there for broader problems.

Despite the tensions, the work proceeded swiftly and on schedule. The small amounts of concentrated fissionable U-235 were hand-carried to the newly created facility at Los Alamos, New Mexico, where, under the leadership of Dr. J. Robert Oppenheimer, they were shaped into the nuclear weapon nicknamed “Little Boy.” Plutonium from Hanford formed the heart of the second bomb, “Fat Man.” The first bomb was dropped over Hiroshima at slightly after 9:00 a.m. local time on August 6, 1945. Three mornings later, the second bomb exploded over Nagasaki. On August 14, Japanese Emperor Hirohito surrendered his nation. World War II ended with the signing of the surrender document in Tokyo Bay on September 2, 1945. In the summer of 1942, General Groves had predicted the United States would have the bomb in three years. Oak Ridgers greeted the news of the Hiroshima explosion with a mixture of enthusiasm for the expected end of the war, concern for the future, and unease growing out of the three-year period of absolute secrecy. But the overall mood was one of self-congratulation and relief.

From the earliest days of the project, the assumption had been that the Manhattan Project was a temporary, wartime endeavor that would be closed with the return of peace. At war’s end, some employees promptly packed up and returned to their former lives or made plans for new opportunities. Others lingered, though, interested in the announcement by Colonel Kenneth D. Nichols, the ranking army officer on the reservation, that the project would continue for at least the immediate future. With the completion of construction, building laborers left, and the number of operating personnel also declined, though not as precipitously. By 1947, when the Atomic Energy Commission took over immediate control of the project, the town’s population had fallen to under 40,000; the 1950 Census showed 30,205 residents, fewer than half its former number, though Oak Ridge was still the fifth largest city in the state. The population of Oak Ridge remained at or near that level for the following fifty years. Control of the facilities shifted from AEC to the Department of Energy in 1977, and Martin Marietta Corporation took over direction of operations from Union Carbide in 1984.

In the years following the war, the town became more “civilian-looking” as occupants painted their homes a variety of colors, Southern Bell took over the operation of the telephone company, and the guard/police force changed uniforms from khaki to blue. In 1949 the gates came down; by the 1950s houses were made available for sale, first to those who occupied them, and then to others. The heritage of cultural activities begun by the earliest Oak Ridgers continued to enrich the life of the community through a myriad of civic organizations, the playhouse, the symphony, the ballet company, the community band, and a variety of concert series.

With the increasing tensions of the Cold War and the inability of the nation to place nuclear weapons under international control or to eliminate them altogether, Oak Ridge and other facilities of the former Manhattan Project continued to be of vital importance to the nation’s defense. But research in nuclear power, radioisotopes, and other aspects of nuclear medicine became a more significant part of the research and development work in Oak Ridge. Cooperation with industry to solve a wide variety of problems was also by the 1980s an increasingly large part of the community’s efforts. Facing a somewhat uneasy future in the mid-1990s with the end of the Cold War and the uncertainties surrounding the use of nuclear power, the large professional/scientific community and the highly skilled work force share the belief that, even with smaller defense budgets, Oak Ridge will continue to function as a leader in high technology enterprises.

Suggested Reading

Richard G. Hewlett and Oscar E. Anderson Jr., The New World, 1939-1946: A History of the Atomic Energy Commission (1962); Charles W. Johnson and Charles O. Jackson, City Behind a Fence: Oak Ridge, Tennessee, 1942-1946 (1981); James Overholt, These Are Our Voices: The Story of Oak Ridge, 1942-1970 (1987); George O. Robinson, The Oak Ridge Story: A Saga of a People Who Share in History (1950); Michael Stoff, The Manhattan Project: A Documentary Introduction to the Atomic Age (1991)

Citation Information

The following information is provided for citations.

  • Article Title Oak Ridge
  • Author
  • Website Name Tennessee Encyclopedia
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  • Access Date June 16, 2024
  • Publisher Tennessee Historical Society
  • Original Published Date
  • Date of Last Update March 1, 2018