Print This Page


A World War II Secret City


Oak Ridge was built under a cloak of great secrecy during World War II. A city and three manufacturing plants of unprecedented scope were constructed to develop a technology that ended the war.

Oak Ridge was created in 1942 as a major site of the "Manhattan Project," a massive wartime effort which produced the world's first atomic weapons. The 60,000-acre tract on which the town and its plants were built met military requirements for isolation, electric power, water, labor and accessibility to nearby highways and railroads. At that time, the area was populated by 3,000 persons residing in approximately 1,000 homes scattered throughout the communities of Scarboro, Wheat and Robertsville.

Scientists had learned by 1939 that uranium atoms could be split with the release of large amounts of energy. This process was called fission. Its use for military purposes was seriously discussed since development of an atomic weapon was considered vital to national security. Albert Einstein sent a letter to President Franklin D. Roosevelt expressing the views of several leading scientists and explaining the potential of such a weapon.


Early in 1942, it was determined that two methods could be used to produce necessary fissionable material--either plutonium 239 or the highly purified isotope uranium 235. Ultimately, three methods were brought to large-scale production. Oak Ridge played a major role in each of these processes. Three facilities, each identified by a code name, were built in the Oak Ridge complex, then called the Clinton Engineering Works after the nearby town of Clinton. This work was performed under the direction of the Manhattan District of the Corps of Engineers which had been formed in June 1942 to oversee the entire atomic weapons program.

The Y-12 Plant was built to separate the uranium 235 isotope from natural uranium in sufficient quantity and quality to produce the fissionable material for atomic weapons. It was the first to accomplish this goal. This plant utilized an electromagnetic process developed at the University of California at Berkeley and had the unusual distinction of using $300 million worth of silver borrowed from the U.S. Treasury. The silver was used as a substitute for copper in the fabrication of equipment for the plant. Uranium separation by the electromagnetic process ended in 1947 at the Y-12 Plant. However, research & development and specialized production continue today at this facility which is still identified by its wartime code name.

Another enormous facility, the K-25 Plant, was built to separate uranium 235 by a more economical method. This plant was one of the largest scale-ups of laboratory equipment in history and involved process systems of unprecedented vacuum tightness and cleanliness. The original K-25 Plant covered more than 1,500 acres and was the forerunner of similar facilities in Paducah, Kentucky and Portsmouth, Ohio. Today, these plants are a source of enriched uranium which is used to fuel both military and civilian nuclear power reactors.
A third facility, X-10, was the site where a graphite-moderated nuclear reactor was constructed as a pilot facility for the larger plutonium production complex in Hanford, Washington. This reactor, later used to produce radioisotopes, was closed in 1963. It has been designated a National Historic Landmark and is open to the public. The X-10 area became the Oak Ridge National Laboratory (ORNL) in 1948. ORNL has gained worldwide recognition for its research in the basic sciences, energy systems, environmental technology and safety.

The city, which is approximately 10 miles in length and two miles wide, is located in a valley known as Black Oak Ridge. Reaching a peak World War II population of 75,000, it became the fifth largest city in Tennessee in 2-1/2 years. Original housing included trailers, dormitories, hutments and single family dwellings called cemestos. The single family homes were constructed in a variety of floor plans and sizes designated by letters of the alphabet. These houses were located in the city's hills and valleys and most are still used today. Shopping centers, businesses and schools were located throughout the community and decentralized the city into separate neighborhoods.

The Manhattan District was transferred to the Atomic Energy Commission (AEC) on June 1, 1947. In 1949, Oak Ridge was opened to the public. Six years later, the AEC sold the government-owned houses and land to city residents. Since that time, additional homes and churches have been built. Oak Ridge was incorporated under a City Council-City Manager charter in May 1959. It currently has a population of 28,000 with federal offices, industrial facilities, a major medical center and approximately 800 private firms located here. The Oak Ridge school system has maintained a high ranking both within the state and the southeastern United States. There are many cultural activities including a symphony orchestra, civic ballet and community playhouse. A variety of recreational facilities are also available and they include Melton Hill Lake and numerous parks.


Print This Page

Published by the Oak Ridge Convention & Visitors Bureau.

  Back to Top