The Portsmouth Site, located in Piketon, Ohio, consisted of four main areas historically totaling more than 3,700 acres: the former gaseous diffusion plant, centrifuge facilities, depleted uranium hexafluoride conversion (DUF6) facility and On-Site Waste Disposal Facility (OSWDF). The largest of the three areas is the former gaseous diffusion plant, which consists of three main process buildings (X-333, X-330 and X-326) which housed the gaseous diffusion process equipment, as well as hundreds of supporting facilities. A seven-mile perimeter road contains the process buildings and over 400 structures and facilities.
The OSWDF is located northeast outside of the perimeter road and has a 300-acre footprint, including support facilities. More than 2,200 workers are employed at the site making it one of the largest employment drivers in the region. Currently, at the site, workers are continuing deactivation of the X-330 Process Building and are close to complete with deactivation at the X-333 Process Building.
PortsDemo - Environmental Monitoring
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Portsmouth News
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The 2026 National Cleanup Workshop explored how the U.S. Department of Energy Office of Environmental Management’s restoration and revitalization are helping power and secure the future.September 25, 2026 -
Leaders from the nation’s gaseous diffusion plant complex participated in the “Enriching Communities – A Renewed Purpose for America’s GDP Complex” panel at the National Cleanup Workshop.September 22, 2026 -
The U.S. Department of Energy’s Portsmouth Site reached a significant milestone in the X-333 Process Building demolition when crews safely took down the 66,000-square-foot southwest corner of the 33-acre facility.September 22, 2026 -
The U.S. Department of Energy's Office of Environmental Management released an expression of interest seeking input from American industry on the potential transfer of surplus critical minerals, rare earth elements and other materials located at five EM cleanup sites across the country.September 18, 2026