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
The safety of our workers, our community and the environment is DOE’s top priority. The Department has a robust environmental monitoring program that meets or exceeds state and national regulatory standards.
Portsmouth News
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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 -
With crews in the early stages of demolishing X-333, the second of the Portsmouth Site’s three former uranium process buildings, U.S. Department of Energy Office of Environmental Management leaders at the site are emphasizing the number one priority: safety of the workforce and community. November 25, 2025November 25, 2025 -
Workers have begun demolishing the massive X-333 Process Building, achieving a U.S. Department of Energy Office of Environmental Management priority to begin demolition of the second of the Portsmouth Site’s three former uranium process buildings. November 18 , 2025November 18, 2025 -
Public tour participants heard firsthand accounts from past employees of the former gaseous diffusion plants at the Portsmouth and Paducah sites this year. November 18, 2025November 18, 2025