US Department of Energy (DOE) Office of Environmental Management (EM) crews have cleared all 497 converters (large process components) from the C-333 Process Building at the Paducah site in Kentucky. The clean-up of the former Paducah Gaseous Diffusion Plant (GDP) is a multi-decade undertaking overseen by the EM Portsmouth/Paducah Project Office (PPPO). The total project cost is estimated at $17bn with a projected completion date between 2065 and 2070.
Commenting on removal of the converters, EM PPPO Interim Acting Deputy Manager and Paducah Site Lead April Ladd said: “Every step of this work was planned and executed with worker safety at the forefront. The technological advancements and disciplined approach the teams brought to this effort not only helped safely achieve this milestone but positioned us for continued success as deactivation activities transition to the C-337 Process Building.”
Team members removed, precisely cut and downsized the converters through a segmentation process. With converters weighing upward of 70,000 pounds, some of their contents were reclaimed, compacted and stored onsite for possible reuse. The use of new tools, procedures and knowledge-sharing from the former Portsmouth GDF (Ohio), allowed Paducah team members to dramatically increase productivity while process improvements shortened time for segmentation from roughly 14 days per converter during startup operations to as many as two converters daily. Meanwhile, compaction crews kept pace to prepare and store the contents of the converters onsite, maintaining rigorous safety standards that made the project a success.
Innovation and enhanced methods from custom dust-collection systems to advanced handling equipment for compacting the contents of the converters were essential to optimising performance and safeguarding personnel during the segmentation process.
DOE said crews will apply lessons learned from deactivating C-333 to future process buildings, supporting EM’s long-term vision for holistic cleanup at the Paducah Site. This holistic approach focuses on end use fuelled by community interest in site reuse for economic development while targeting land that has the highest potential for reuse.
“By embracing innovative technologies, engaging in continuous improvement from our workforce, and incorporating feedback from field operations and partner sites, our team set a strong foundation for the next phase of deactivation,” Four Rivers Nuclear Partnership (FRNP) Program Manager Myrna Redfield said. “Everyone involved showed an exceptional commitment to safety and excellence to complete this milestone for the Paducah Site.” FRNP is the deactivation and remediation contractor at the Paducah Site.
While the cleanup is decades-long, land is being transitioned for new use on a rolling basis. In early 2026, a $900m contract was awarded to General Matter to accelerate the construction of a new uranium enrichment facility on a 100-acre parcel of the site, with operations planned by the end of the decade. Although the 2065 end-date remains the official forecast, officials have stated they are actively seeking ways to further “improve that schedule” through lessons learned from other sites including Oak Ridge and Portsmouth.
The original function of the Paducah GDF was to enrich uranium for the US nuclear weapons programme and, later, for commercial nuclear power fuel. The site was constructed on the grounds of the former Kentucky Ordnance Works, a World War II TNT manufacturing facility. While the total site spans over 3,500 acres, only a specific industrial portion is targeted for intensive reindustrialisation although the entire site footprint under review for removal or remediation.
Of more than 500 facilities on the site, over 180 have been demolished to date and more than 560,000 square feet of structures have been removed. At least 320 buildings including the largest process facilities, are still standing. There are four major process buildings including C-333 and C-337. These cover over 74 acres under-roof and are currently being deactivated for future demolition.
However, the task extends beyond just tearing down walls presenting key clean-up challenges. The site sits on one of the largest trichloroethylene (TCE) groundwater plumes in the DOE complex, primarily originating from the C-400 Cleaning Building. The site manages approximately 40,000 remaining cylinders of depleted uranium hexafluoride (DUF6) that must be converted into a stable form by 2057. Crews are also currently working to dispose of roughly 3m pounds of ozone-depleting R-114 refrigerant. Environmental progress is tracked by the Kentucky Division of Waste Management to ensure the site eventually reaches its planned “end state” for industrial reuse.
The Paducah and Portsmouth sites were designed to work in tandem as “sister plants” within a three-site enrichment complex that also included Oak Ridge in Tennessee. Oak Ridge, Paducah, and Portsmouth formed a single integrated system for uranium enrichment. Oak Ridge serves as the historical and technical blueprint for the entire gaseous diffusion complex. It was the first site to use this technology and now serves as the “finish line” model for the Paducah and Portsmouth cleanups.
Historically, the plants operated in a sequence. Paducah served as a feed facility, enriching natural uranium to low levels (about 2-2.75%). This product was then shipped to Portsmouth for top-off enrichment to much higher levels (up to 95% for weapons or 4–5% for commercial fuel).
Oak Ridge (K-25) was the prototype built in 1943 during the Manhattan Project to fuel the first atomic bomb. Clean-up has been completed with all five major process buildings gone by 2017. It is now the East Tennessee Technology Park with 25+ private businesses.
Paducah, the Feed Plant was built in 1952 to provide low-enriched uranium to the other two sites. Currently it is deactivating its four process buildings. Clean-up is in early stages with only the first 100 acres leased for new nuclear development.
Portsmouth, the Finisher Plant, was built in 1954 to “top-off” uranium to high weapons-grade levels. Clean-up is halfway through with one of three process buildings demolished and demolition of a second imminent. It is transitioning parcels of land to the Southern Ohio Diversification Initiative.
