Depleted uranium hexafluoride (DUF6) Conversion
For more than 60 years the DOE Gaseous Diffusion Plants enriched uranium for use in nuclear weapons and later began supplying enriched uranium to the commercial nuclear industry. DUF6 is a coproduct of the uranium enrichment process that operated at the Paducah and Portsmouth Sites, as well as the gaseous diffusion plant in Oak Ridge, TN. The DUF6 Conversion Project provides for the operation of facilities at the PPPO Sites in Ohio and Kentucky to convert the stored DUF6 into depleted uranium oxide, a more stable chemical form that can be reused, stored, or disposed of. A coproduct of the conversion process is hydrofluoric acid (HF), which is reused industrially.
There are approximately 800,000 metric tons of DUF6 at the two sites. The Portsmouth DUF6 inventory is expected to be processed in approximately 18 years and Paducah’s larger inventory within 30 years.
DUF6 Cylinder Program
DUF6 is a solid at ambient temperatures and is stored in large metal cylinders. Cylinders are stored in outdoor facilities, commonly referred to as cylinder storage yards. The inventory varies from time to time, as a result of DOE agreements to receive or market DUF6. Stored as a crystalline solid at less than atmospheric pressure, when DUF6 is exposed to moisture in the atmosphere, hydrofluoric acid and uranyl fluoride form. The compounds form a hard crystalline solid that acts as a self-sealant within the storage cylinder.
The mission of the DUF6 Cylinder Program is to safely store the DOE-owned DUF6 inventory until its ultimate disposition. DOE has an active cylinder management program that includes cylinder and cylinder yard maintenance, routine inspections, and other programmatic activities such as cylinder corrosion studies. The program maintains a cylinder inventory database that serves as a systematic repository for all cylinder inspection data.