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 U.S. Department of Energy’s community reuse organization at the Portsmouth Site is seeing decades of efforts to redevelop the former gaseous diffusion plant pay off.November 3, 2026 -
The U.S. Department of Energy’s Office of Environmental Management awarded the Portsmouth Infrastructure Support Services contract to AIS Technical Services LLC, a small business from Tempe, Arizona, to perform infrastructure support services at the Portsmouth Site, including its gaseous diffusion plant.October 30, 2026 -
First Senate-confirmed EM leader in more than six yearsOctober 20, 2026