The Beginnings of Oak Ridge & The Secret City

{Robert Bailey – Roane County Historian}

There have been many important events that have occurred throughout the history of Roane County. The coming of industry to create Rockwood, the Temperance movement which brought about Harriman, the Tennessee Valley Authority which brought power to rural areas and many others made dramatic impacts in Roane County. However, the creation of “Oak Ridge” may have had the most impact. The bombing of Pearl Harbor by the Japanese brought the United States into World War II. Here in Oak Ridge and other plants in the United States, the atomic bomb was developed which were dropped on the cities of Hiroshima and Nagasaki.

The development of the atomic bomb had to be kept top secret. The first code name for the project was called the “Kingston Demolition Range” but was later renamed “Clinton Engineer Works” after the city of Clinton. One of the reasons this area was chosen was that the area was isolated. It also had power provided by T.V.A., and there were two railroads. Land acquisition began in the fall of 1942. Approximately 56,200 acres in Roane and Anderson Counties were acquired for the project. An important aspect of the land was the ridges which divided the valleys. A plant was located in each valley. At this time there were only about 1,000 families in the area. The average cost of an acre paid was $45 per acre. However, many families received much less. Among the items located in the Roane County Archives are the maps of the Kingston Demolition Range showing all the owners of the different properties which were acquired by the Federal Government.

Among the acquisitions was the Wheat High School, located near the K-25 plant, which was only one of three High Schools ran by Roane County. The other two were Roane County High and Rockwood High. The Harriman High School was run by the City of Harriman. Most of the homes, barns and other outbuildings were destroyed to discourage people and others from moving into them. Those buildings not torn down were used for storage. Two churches, the George Jones Baptist church near the K-25 plant and the New Bethel Baptist Church near the Oak Ridge National Laboratory (X-10), which was used for storage, were not torn down and are all that remain in the Oak Ridge part of Roane County before the building of the city.

The Gaseous Diffusion Plant (K-25) was the first of the three (K-25, X-10, and Y-12) plants to be built. Construction of the Gaseous Diffusion Plant (K-25) began in 1943 and was built primarily by the J.A. Jones Construction Co., of Charlotte, N.C. at the cost of about $500 million. Carbide and Carbon Chemical Company, later Union Carbide Corporation, became the operating contractor because of its experience in the chemical and metallurgical fields and earlier contributions to the atomic energy program. K-25 was the war code name for the plant “K” representing the Kellex Corporation which designed the plant. In 1945, about 10 percent of all the electric power generated in the United States was required to operate K-25. It consisted of five process buildings—K-25, K-27, K-29, and K-33 and about 70 auxiliary buildings covering about 640 acres. The U-shaped K-25 building was a half-mile long and was the largest building in the world under one roof at that time. Each wing is 2,450 feet long, averages 400 feet in width, and is 60 feet in height. The total area of the building covered 44 acres. Along with K-27, the K-25 process building was shut down in 1964. The plant produced large quantities of enriched uranium-235 from uranium 238 through the gaseous diffusion process to be used either in weapons or to fuel nuclear reactors.

K-25 Footprint

K-25 Aerial View

K-25 Union Carbide Corp USAEC

X10 Reactor Face


The X-10 (Oak Ridge National Laboratory) plant was built by DuPont for 12 million dollars and completed in October 1943. The letter “X” was used by the University of Chicago in its description of the area. The number 10 had no special significance. It was much smaller than the K-25 and Y-12 plants. During the war, it employed 1,513 people. The primary mission was to build a Graphite Reactor to show that the production of plutonium from uranium in a reactor could fuel an atomic bomb. Its job was to show that plutonium could be extracted from irradiated uranium slugs, and its first major challenge was to produce a self-sustaining chain reaction. And in 1944, chemists produced the world’s first few grams of plutonium. The Graphite Reactor operated from 1943 to 1963. Among the accomplishments through the years at X-10 were:

(1) Production of the first electricity from nuclear energy;
(2) The first reactor was used for studying the nature of matter and the health hazards of radioactivity.
(3) Providing radioisotopes for medicine, agriculture, industry, and other purposes.

The Oak Ridge National Lab is a world-wide known research center for energy, environment, and other things. The Graphite Reactor was declared a registered National Historic Landmark in 1966 and is Roane County’s only such National landmark.

The Y-12 plant was designed and constructed by the Stone and Webster Engineering Corporation of Boston at the cost of about $427, 000. The name of the plant has no special significance. It contained about 170 buildings and was built on 500 acres. The plant was put into use by the operating company, the Tennessee Eastman Corporation of Kingsport, TN, in January 1944. At its peak in 1945, it employed 22,000 people. Its purpose was to separate uranium atoms (U-235 from U-238) using an electromagnetic process developed by Dr. E.O. Lawrence of the University of California. It was the first and only plant of its kind in the world. Y-12 separated the uranium that was used in “Little Boy” the uranium bomb which was dropped on Hiroshima, Japan on August 6, 1945. It was the first atomic bomb to be used as a weapon. The other bomb, “Fat Man,” a plutonium bomb, which was developed in Hanford, Washington, was dropped three days later on Nagasaki, Japan. After the war, the plant started manufacturing uranium components for nuclear weapons. The construction of parts for nuclear weapons by the Y-12 plant played an important part in eventually ending the Cold War with the Soviet Union.

Knoxville News-Sentinel Headline

Originally written for the Roane County Newsletter to the Community between June and September 2012.