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.  



EM Names Knerr as Deputy Manager of Portsmouth/Paducah Project Office
January 17, 2023
EM has selected Reinhard Knerr, manager of the Carlsbad Field Office (CBFO), to serve as deputy manager of the Portsmouth/Paducah Project Office (PPPO) in Lexington, Kentucky, effective Jan. 29.
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White Joins Members of Congress to Celebrate Portsmouth’s 70th Anniversary
December 6, 2022
EM Senior Advisor William “Ike” White recently joined elected officials, local stakeholders and nearly 2,000 employees at the Portsmouth Site to celebrate the gaseous diffusion plant’s 70th anniversary.
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Portsmouth Tests Electric Mowers to Cut Emissions, Enhance Safety
December 6, 2022
EM’s Portsmouth Site recently evaluated the use of electric mowers to provide a safer, greener future for grounds maintenance activities.
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Portsmouth Site Marks 70th Anniversary With 'Past, Present, Future' Celebration
November 22, 2022
EM’s Portsmouth Site marked its 70th anniversary on Monday with its “Past, Present, Future” celebration.
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