The Department of Energy’s nuclear cleanup branch said Tuesday it has now reduced its inventory of depleted uranium hexafluoride (DUF6) cylinders at the Portsmouth Site in Ohio by 20%.
DOE’s Office of Environmental Management announced Tuesday its AtkinsRéalis-led contractor Mission Conversion Services Alliance (MCSA) has converted DUF6 from 4,500 cylinders at Portsmouth, into a safe form for storage, disposal or reuse. That represents more than 20% of the site’s inventory.
MCSA has the operations contract that includes DUF6 conversion at both Portsmouth and its sister gaseous diffusion plant, the Paducah Site in Kentucky, DOE said in the news release. At one time, Portsmouth had more than 20,000 cylinders of DUF6, left over from decades of uranium enrichment for defense and commercial nuclear power uses.
Portsmouth and Paducah together converted more than 1,000 cylinders of DUF6 into oxide form during fiscal 2026. This week’s DOE press release did not say how many DUF6 cylinders were treated at Paducah during fiscal 2026.
Before the conversion process began, DOE had 67,000 cylinders of DUF6 stored at Portsmouth, Paducah and the Oak Ridge Site in Tennessee.
Commercial nuclear companies and DOE’s National Nuclear Security Administration are looking to use some of the converted DUF6 for beneficial purposes.
Converting each cylinder of DUF6 into safer uranium oxide powder can take up to 30 hours, split amongst the heating and conversion process, DOE said in the release.
Portsmouth crews beat their fiscal 2026 production goal of converting DUF6 from 546 cylinders two months ahead of schedule, DOE said.
Mission Conversion Services Alliance is a joint venture made up of partners Atkins, Amentum and Westinghouse. It has a contract, currently valued at about $2.5 billion, which started in June 2025 and is slated to run through September 2030.
