About the Oak Ridge Reservation

About the Oak Ridge Reservation

The Department of Energy Oak Ridge Reservation (ORR) consists of approximately 37,000 acres of federally owned land in Anderson and Roane Counties. The ORR is bounded on the north and east by the City of Oak Ridge boundary, and on the south and west by the Clinch River. The western part of the ORR boundary lies just outside the City of Oak Ridge corporate limits.

Approximately 25,000 of the ORR’s roughly 37,000 acres have remained undeveloped in a relatively natural state. Approximately 20,000 of the 25,000 acres have been designated a DOE National Environmental Research Park, an international biosphere reserve, and part of the Southern Appalachian Man and the Biosphere Cooperative.

The entire ORR was designated a CERCLA site (“Superfund Site”) by the U.S. Environmental Protection Agency (EPA) in 1989. About 15% of the ORR is contaminated by hazardousand radioactive materials, including waste sites or remediation areas. This legacy contamination is being cleaned up in accordance with the existing Federal Facilities Agreement. The Tennessee Division of Remediation’s Oak Ridge Office oversees all environmental protection and restoration activities on the ORR.

Click here for more information about the Tennessee Division of Remediation and the Federal Facility Agreement:


The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced materials for the first atomic bombs. The reservation’s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the previous and current missions involve the use of radiological and non-radiological hazardous materials.

The ORR consists of three government owned, contractor operated sites: East Tennessee Technology Park (ETTP), Oak Ridge National Laboratory (ORNL) and Y-12 National Security Complex (Y-12). Only two of those sites, ORNL and Y-12, have the potential to have a classified emergency that would require citizens to take protective actions.

East Tennessee Technology Park

The East Tennessee Technology Park (ETTP) is the westernmost of the three ORR sites, located in Roane County within the City of Oak Ridge. ETTP’s administrative footprint is approximately 5,000 acres. The ETTP is in Emergency Planning Sector K.

Construction of the Oak Ridge Gaseous Diffusion Plant (known during the World War II-era as K-25) was initiated in 1943 as part of the U.S. Army's Manhattan Project. K-25’s original mission was production of highly enriched uranium for nuclear weapons. The mission was later expanded to include production of enriched uranium for fabrication into fuel elements for nuclear reactors. Military production of highly enriched uranium ceased in 1964. After the gaseous diffusion process was shut down in 1985, the primary mission changed to environmental restoration and associated waste management. In 1997, the site was renamed East Tennessee Technology Park to reflect an added mission of reindustrialization and reuse of assets through leasing to private industry.

In 2020, DOE completed core cleanup at the site including the demolition of more than 500 structures and addressing major areas of soil contamination. To date, more than 1,300 acres, along with major site infrastructure, have been transferred for economic development with another 600 acres slated for transfer in the years ahead. Another 3,000 acres have been placed in a conservation easement that is open to the public for recreational use, and more than 100 acres have been set aside for historic preservation efforts as part of the Manhattan Project National Historical Park to commemorate and share the stories of the men and women who built and operated the site. With all demolition complete, the remaining soil and groundwater remediation is expected to continue through 2024.

Although a recognized ORR site, the ETTP does not have any hazardous materials that would require citizens to take protective actions.

Click here for more information on the ETTP site:


Oak Ridge National Laboratory

The Oak Ridge National Laboratory (ORNL) is located within the city limits of Oak Ridge, in both Roane and Anderson Counties. The total land area comprising ORNL’s Emergency Response Area approaches 16,285 acres. The Laboratory proper, known as the “X-10 Site,” encompasses 330 acres with outlying facilities and waste management storage encompassing another 1135 acres. The remaining acres are mostly undeveloped eastern deciduous forestland including the DOE National Environmental Research Park. The ORNL is in Emergency Planning Sector X.

Currently, there are more than 4,000 employees, including scientists and engineers in more than 100 disciplines. Over 3,000 facility users and scientists visit the ORNL each year.

ORNL was originally established in 1943 as the “Clinton Laboratories” to pioneer a method for producing and separating plutonium. Since the end of World War II, ORNL has no nuclear weapons mission. ORNL's current science and technology missions focus on materials, neutron science, high-performance computing, and nuclear. ORNL also partners with the state of Tennessee, universities and industries to solve challenges in energy, security and scientific discovery.

Click here for more information on the ORNL site:


Y-12 National Security Complex

The Y-12 National Security Complex (Y-12) is in the eastern portion of the ORR within the corporate limits of the City of Oak Ridge in Anderson County. The center of Y-12 is about three miles southwest of the main business district of the City of Oak Ridge and about 20 miles west-northwest of Knoxville. The closest residents to Y-12 are located in the city’s Scarboro neighborhood. The Y-12 is in Emergency Planning Sector Y.

Y-12 spans 811 acres in the Bear Creek Valley, 2.5 miles in length between its east and west boundaries down the valley and 1.5 miles in width across the valley. Housed within its borders are manufacturing, production, laboratory, support, and research and development areas. While modernization/transformation activities have reduced the footprint of operating facilities, Y-12 remains a highly developed area. Nearly 600 of the 800 acres at Y-12 are enclosed by perimeter security fences.

Y-12 was constructed as part of the World War II Manhattan Project. Construction began in February 1943 with operations commencing in November of that year. The first mission was the separation of uranium-235 from natural uranium by the electromagnetic separation process. In the years following World War II, Y-12 evolved into a high-precision manufacturing assembly and inspection facility while maintaining the nation's uranium and lithium technology base.

Y-12’s current missions include production and rework of complex nuclear weapon components; receipt, storage, and protection of special nuclear materials; supplying the U.S. Navy with material for fabrication of reactor fuel; preventing the spread of weapons of mass destruction; and support to DOE and other Federal agencies.

Click here for more information on the Y-12 site: