DUF6 CONVERSION PROJECT

Uranium Disposition Services, LLC, (UDS) has been contracted by the U.S. Department of Energy (DOE) to disposition the depleted uranium hexafluoride (DUF6 ) that has been stored at three sites: Paducah, Kentucky; Portsmouth, Ohio; and the East Tennessee Technology Park(ETTP) in Oak Ridge, Tennessee. DUF6 is a by-product of the uranium enrichment process used to make uranium suitable for use as fuel for nuclear reactors or in national security applications.

The primary objectives of the UDS DUF6 Conversion Project are to design, construct, and operate conversion facilities on DOE property at the Portsmouth and Paducah sites. These facilities will convert the DOE inventory of DUF6 now located at the Paducah and Portsmouth Gaseous Diffusion Plants, and the ETTP, to a stable chemical form acceptable for beneficial use/reuse and/or disposal. (DUF6 cylinders previously located at ETTP have been transferred to the Portsmouth site for conversion.) In addition, UDS will provide surveillance and maintenance of the DOE inventory of cylinders containing DUF6, low-enriched uranium hexafluoride, and natural assay uranium hexafluoride.

Over fifty years of Gaseous Diffusion Plant operations have resulted in nearly 700,000 metric tons of DUF6 in storage at the Oak Ridge, Paducah, Portsmouth sites.

The inventory at each site:

In 2002, DOE awarded the contract to UDS to design, build and operate DUF6 conversion plants at the Paducah and Portsmouth sites.

Processing capacity

Products

The conversion process is a proven technology based on the dry conversion facility currently operating in Richland, WA under Nuclear Regulatory Commission license. The plant has operated safely and has been environmentally compliant for over 10 years.

The conversion process begins with DUF6 in solid form contained in a feed cylinder. These cylinders are placed into autoclaves and heated to vaporize and transfer the UF6 from the cylinder into the process. In the conversion process DUF6 is reacted with steam and hydrogen, which results in the formation of a uranium oxide and aqueous hydrogen fluoride. The process also includes scrubbers, filters, and monitoring equipment to assure proper conversion and to eliminate releases into the atmosphere.

The chemical equations below show the chemical reaction which takes place in the process.

The following diagram depicts the conversion process

The two products of the conversion are Uranium Oxide and Hydrogen Fluoride.

UOx - Uranium Oxide is more chemically stable than UF6 and will be disposed in a permitted low level waste site. Some small amount of the material may be stored or reused.

HF - Hydrogen Fluoride is produced in aqueous form and has commercial value.                                      Return to top