U.S. DOE Portsmouth Decontamination and Decommissioning

Client: U.S. Department of Energy (DOE)

Location: Pike County, OH, U.S.

Map showing the location of U.S. DOE Portsmouth Decontamination and Decommissioning

Executive Summary

For more than 15 years, Fluor has been supporting the U.S. Department of Energy (DOE) mission to decontaminate and decommission (D&D) the Portsmouth site. Located near Piketon, Ohio, the 3,700-acre nuclear industrial site includes a former gaseous diffusion plant and the On-Site Waste Disposal Facility (OSWDF).

DOE awarded a $4.6 billion D&D contract to Fluor-BWXT Portsmouth, LLC, a Fluor-led partnership, in 2010. In 2025, the Southern Ohio Cleanup Company, LLC, which includes team members Amentum and Fluor, assumed responsibility for the site under a new $5.87 billion follow-on contract.

Since 2010, a team of contractors and a workforce of more than 2,000 have decontaminated and decommissioned over 10 million square feet of contaminated facilities at the DOE site including more than 133 buildings.

Client's Challenge

The DOE faced the challenge of safely dismantling more than 315 facilities, dispositioning the associated material and process equipment, and remediating more than 600,000 cubic yards of contaminated soil. The project included two major efforts: decommissioning the site's three primary process buildings, which together contain roughly 10 million square feet of heavily contaminated space, and designing and constructing the On-Site Waste Disposal Facility – a $650 million, 100-acre landfill to safely isolate over 2 million cubic yards of low-level radioactive and toxic debris generated during plant demolition.

The gaseous diffusion plant was built by the federal government in the early 1950s as part of the nation's nuclear weapons complex. The site enriched uranium until 2001. The three primary process buildings, which cover more than 30 acres each, were built to house thousands of pieces of uranium enrichment equipment and the resulting hazardous waste. Each building represented a different tier of a giant engineering cascade, allowing uranium gas to be pumped sequentially through thousands of individual stages to increase its concentration.

Fluor's Solution

Through an integrated D&D strategy, Fluor and our partners have achieved unprecedented progress in the cleanup of the Portsmouth site. The team successfully demolished the half mile-long X-326 process building and completed the intricate deactivation of the second structure, the 82-foot-tall X-333 building. Spanning 66 acres, X-333 is the largest of the plant's three process buildings and a top DOE Office of Environmental Management priority. With more than 600 uranium enrichment converters safely isolated, structural teardown of X-333 is underway and slated for completion by 2030. Concurrently, we have initiated preparatory deactivation on the third and final process building, X-330.

We collaborate closely with all stakeholders, including our client, labor unions, regulators, and advisory boards, to champion a shared vision for the Portsmouth Site. Through strategic community partnerships, the team is actively preparing vital acreage for regional reindustrialization, new job creation, and future commercial use.

Conclusion

Fluor continues to play a critical role in the cleanup mission at the Portsmouth Site. Our driving focus remains safely completing D&D activities and transitioning the site into a finalized end state that satisfies our client’s needs and delivers lasting value to the surrounding communities.

Learn more at the Portsmouth website