The Portsmouth plant enriched uranium from 1954 until 2001 through a process called gaseous diffusion.

The Portsmouth Gaseous Diffusion Plant operated from 1954 to 2001. Located in Pike County, Ohio, the plant occupies about 1,200 acres of the 3,777-acre federally-owned Portsmouth Site. The plant was one of three large gaseous diffusion plants in the United States initially constructed to produce enriched uranium to support the nation’s nuclear weapons program and, in later years, enriched uranium used by commercial nuclear reactors. After the Cold War, weapons-grade uranium enrichment was suspended and production facilities were leased to the private sector. In 2001, enrichment operations were discontinued at the site. 

DOE's Office of Environmental Management began its environmental cleanup program at the site in 1989 and the effort continues today in cooperation with the U.S. and Ohio Environmental Protection Agencies.  Decontamination and decommissioning (D&D) of the plant commenced in 2011 and is ongoing.  



Portsmouth, Paducah Kick Off Major Uranium Oxide Disposal Effort
May 9, 2023
EM has successfully commenced a major disposal effort for a key uranium-enrichment byproduct with the recent arrival of 60 uranium-oxide storage cylinders by rail at a licensed facility in west Texas.
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DOE Honors Two EM Sites for Increasing Use of Zero-Emissions Vehicles
April 25, 2023
Just in time for Earth Day, DOE named EM’s Portsmouth Site and Idaho Cleanup Project (ICP) as Green Fleet Award recipients last week for their exceptional efforts in ordering the most light-duty zero-emissions vehicles (ZEV) in fiscal 2023.
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DOE Recognizes Two EM Sites for Exceptional Project Management
April 18, 2023
Deputy Energy Secretary David Turk presented EM two Project Management Awards during a ceremony last week, recognizing exceptional results for complex projects.
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Coordination is Key as Portsmouth Crews Downsize Facility’s Components
February 28, 2023
Workers are moving nearly 5,000 tons of equipment from the X-333 Process Building to a demolition pad where the X-326 Process Building once stood at EM’s Portsmouth Site.
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