Modernizing DUF6 Facilities to Enhance Safety, Boost Performance

Technicians at the Paducah Depleted Uranium Hexafluoride Conversion Project facility prepare to install a newly fabricated cold box, part of a major system upgrade designed to eliminate vacuum pump failures and boost processing efficiency up to 15%.

LEXINGTON, Ky. — The Portsmouth Paducah Project Office (PPPO) is modernizing its depleted uranium hexafluoride (DUF6) conversion facilities by installing a new system designed to significantly enhance safety, improve efficiency and reduce operational pauses.

“This upgrade is a great example of how smart engineering can solve persistent challenges,” PPPO DUF6 Program Manager Zak Lafontaine said. “By replacing aging vacuum pumps with a more reliable and efficient system, we’re not only improving safety and performance, but we’re also reducing operational pauses and maintenance. It’s a practical, forward-looking solution that further reinforces the long term success of the DUF6 mission.”

Earlier this summer, PPPO met a U.S. Department of Energy (DOE) Office of Environmental Management priority for 2025 after successfully converting more than 1,000 cylinders of DUF6 into a safer, more stable oxide form.

The DUF6 material, a coproduct of decades of uranium enrichment for defense and commercial energy purposes, poses long term storage and environmental challenges in its original form. Through conversion to uranium oxide, the DUF6 team is helping mitigate those risks and advance DOE’s cleanup mission.

A cold box is shown being assembled at a facility in Cincinnati, Ohio. Once installed at the U.S. Department of Energy Office of Environmental Management’s Depleted Uranium Hexafluoride Conversion Project facilities, these units will enable gas-phase uranium hexafluoride transfers and reduce cylinder processing time by two to three hours.

Currently, the DUF6 conversion process relies on small vacuum pumps to remove residual uranium hexafluoride (UF6) from heated cylinders during the final stages of processing. These pumps have been prone to failure, resulting in repairs and operational pauses. The new system will eliminate the need for these pumps by performing this transfer process more reliably and efficiently using cold box chambers to freeze the residual UF6 in receiving UF6 cylinders under vacuum.

These improvements will deliver higher UF6 processing rates than is achievable in conventional designs. A key benefit of this upgrade includes increased throughput, as the new system is expected to reduce processing time by approximately two to three hours per cylinder — representing a 10 to 15% increase in throughput.

The new system also provides a means of transferring the entire volume of UF6 contents between cylinders in the gas phase, a capability not previously available at the DUF6 project. The addition of a cold box improves the conversion process by making it more efficient and reliable. It helps cool and recycle process gases, which saves energy, reduces emissions, and supports safe and sustainable operations at the plant. The number one priority is safety, and all upgrades completed at the facilities undergo a rigorous safety analysis to ensure they meet the highest standards of operational safety and regulatory compliance.

“This upgrade represents a major step forward in our commitment to safe, efficient and cost-effective management of legacy nuclear materials,” Mid-America Conversion Services (MCS) Program Manager Dutch Conrad said. “We’re proud to support this mission with innovative engineering solutions and a focus on continuous improvement.”

MCS is the contractor charged with managing the DUF6 facilities at EM’s Portsmouth and Paducah legacy nuclear sites.

The cold box installation is scheduled for completion by the end of this year at the Paducah facility, with Portsmouth following in the fall next year.

The DUF6 project draws from innovative methods and technologies to manage and convert DUF6 into usable materials, ensuring compliance with all safety and environmental regulations. PPPO conducts operations of the DUF6 conversion plants as required by Public Law 107-206.

-Contributor: Kearney Canter