The U. S. Army Corps of Engineers began acquiring land, in the area that became Oak Ridge, in October 1942 for the Manhattan Project. By March 1943, 56,000 acres were sealed behind fences and major industrial facilities were under construction. The K-25, S-50, and Y-12 plants were all built to separate the fissile isotope uranium-235 from uranium-238, while the X-10 site was established as a pilot plant for the Graphite Reactor.
Throughout the next six decades the three major sites— K-25 (present day ETTP), X-10 (present day ORNL), and Y-12— purified isotopes, conducted research, built weapons, and created environmental legacies that Oak Ridge’s EM program is now cleaning and removing.
East Tennessee Technology Park—Construction of the K-25 plant began in June 1943 and completed in early 1945. The massive U-shaped K-25 building, encompassing 44 acres, housed hundreds of cascades needed for the gaseous diffusion process to isolate uranium-235. The plant supplied the uranium-235 used in the first atomic bomb. During the Cold War, gaseous diffusion was the only uranium enrichment process used to produce weapons-grade uranium. The original plant was expanded to cover more than 1,500 acres and employed 12,000 workers in hundreds of buildings. At its peak, the site contained five uranium enrichment facilities—K-25, K-27, K-29, K-31, and K-33.
Since nuclear non-proliferation reduced the need for weapons, the K-25 plant ceased gaseous diffusion operations in 1987. Additionally, a centrifuge uranium separation program that began in 1975 was terminated in 1985. Environmental hazards and the deteriorating structural integrity of on-site buildings rendered a majority of the K-25 plant unviable. Environmental cleanup began at the site in the early 1990s, and it was renamed the ‘East Tennessee Technology Park’ in 1997 to begin its transition into a privately owned and operated industrial park.
Y-12 National Security Complex—Construction of the first building at the Y-12 Plant, 9201-1, began in February 1943. Y-12 used Calutrons to separate uranium isotopes for the first atomic weapons. By the end of the war, all of the Alpha and Beta buildings were constructed and more than 22,000 workers worked at the plant. The uranium-235 separated by Y-12 was used in the Little Boy bomb.
The 1950s Cold War brought growth and change to Y- 12 as new processes for separating lithium-6 were added. It was during this period, and the early 1960s, that large amounts of mercury entered the environment from operations. From 1960 to 1990, Y-12 expanded and steadily improved its precision machining and measurement capabilities. However, with an estimated 700,000 pounds of mercury already released into the environment, public and Congressional concern began to mount in the 1970s and escalated in the late 1980s.
With the end of the Cold War in 1990, Y-12’s mission changed from production to weapons reductions
and disassembly, and in 2000, Y-12 was placed under the jurisdiction of the National Nuclear Security Administration. EM supports Y-12’s missions and modernization by deactivating and demolishing
World War II-era facilities and remediating mercury and other contaminants that were released to the environment.
Oak Ridge National Laboratory—Construction of X-10, also known as the Clinton Laboratories, began in February 1943. X-10’s mission was to develop and test the experimental Graphite Reactor, which went critical in March 1944. Since then, ORNL designed and built many reactors, including 12 on-site, and developed or participated in developing numerous nuclear materials reprocessing methods.
In the 1960’s, research into genetics and the biological effects of radiation were added to the site’s mission. In the 1970’s, the site began ecological and biological research concerning the environmental effects and safety of nuclear power plants. During the 1980s and 1990s, ORNL’s mission grew to encompass alternative energy and Strategic Defense Initiative research.
During the past ten years, ORNL has grown and expanded its capabilities rapidly, from supercomputing to materials exploration and research in the biomedical, environmental, nuclear physics arenas.
ORNL’s Sustainable Campus initiative aims to modernize research and support facilities using environmentally friendly green technologies. Unfortunately, decades of research and development resulted in contaminated soils and groundwater. EM responded by remediating and capping large areas in Melton Valley that were formerly used for waste disposal. In addition, EM supports ORNL’s revitalization by decontaminating and demolishing excess structures and continuing its environmental restoration efforts.