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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Thanks to their safe and successful cleanup work in 2025, the Portsmouth and Paducah sites demonstrated the strong role the U.S. Department of Energy Office of Environmental Management plays in advancing American energy dominance and innovation. December 23, 2025December 23, 2025 -
Cleanup program recently awarded performance-based fee payments to 12 of its contractors at sites across the DOE complex. December 23, 2025December 23, 2025 -
Helping to grow America’s burgeoning nuclear renaissance, advancing infrastructure critical to winning the artificial intelligence race and safely addressing aging facilities to contribute to the modernization of America’s strategic deterrent — these are just some of the ways the U.S. Department of Energy Office of Environmental Management helped enable American energy, innovation and security in 2025, according to a new document released today.December 23, 2025 -
The Portsmouth Site announced the start of structural demolition on the X-333 Process Building last month, almost 70 years to the day it was turned over to the Atomic Energy Commission, a predecessor agency to the U.S. Department of Energy, to assume the facility’s role in fueling America’s fight in the Cold War. December 9, 2025December 9, 2025