SBIR-STTR Award

DOE is responsible for managing nearly 1.5 billion pounds of uranium hexafluoride store in carbon steel cylinders in Ohio, Kentucky, and Tennessee. The cylinders are corroding and beginning to become an evironmental concern in the affected states. The cost of converting these cylinders to a more stable form such as an oxide is estimated at about $2 billion. If valuable chemicals can be produced from the fluorine portion, the overall management cost to DOE and the taxpayers will be reduced. This project will develop technology for extracting the fluorine in the uranium hexafluoride and producing high value, high purity gases for use in the semiconductor industry. These gases—tungsten hexafluoride and germanium hexafluoride—are used for chemical vapor deposition in semiconductor manufacturing. During Phase I, the basic chemistry of the conversion process will be established, kinetic conversion rates will be determined at laboratory scale, and gas purity levels will be established. Process design data will be obtained to allow the design of a pilot plant for subsequent demonstration in Phase II. Commercial Application and Other Benefits as described by the awardee: Gases should be produced that can be sold to semiconductor chip makers. These gases are but two of several similar gases that will be produced from the uranium hexafluorine as it is converted to the more stable oxide.

DOE is responsible for managing nearly 1.5 billion pounds of uranium hexafluoride stored in carbon steel cylinders in Ohio, Kentucky, and Tennessee. The cylinders are corroding and beginning to become an environmental concern. The cost of converting these cylinders to a more stable form, such as an oxide, is estimated at about $2 billion. If valuable chemicals can be produced from the fluorine portion, the overall management cost to DOE and the taxpayers will be reduced. This project will develop technology to extract fluorine from uranium hexafluoride and produce high value, high purity gases for use in the semiconductor industry. These gases (tungsten hexafluoride and germanium hexafluoride) are used for chemical vapor depo-sition in semiconductor manufacturing. Phase I demonstrated that germanium and tungsten oxides would react with uranium tetrafluoride to produce the respective gaseous metal fluorides. In addition to studying the basic reactions, the sensitivity of the conversion process to temperature, heating rate, and in some cases, variations in the starting material were also investigated. Phase II will develop a production process for generation, capture, and purification of GeF4 to the point that it is market-ready for existing semiconductor applications. Phase II will also include engineering development and scaleup of processes for WF6 manufacture.

Commercial Applications and Other Benefits as described by the awardee:
Successful imple-mentation of this project will produce titanium metal, a high-value metal product that can be sold as a powder or ingot, and a fluoride product (cryolite or HF). Both products should be used in very large quantities by industry.