This SBIR Phase I project will develop a program to utilize uranium tetrafluoride (DUF4), a processed byproduct from the creation of nuclear energy, to create SF4, SF6, and NF3. SF4 and SF6 would be created by mixing DUF4 with sulfur oxides and halides (and oxygen for SF6) at varying temperatures, pressures, and stoichiometries. In addition, the generated SF4 would be mixed at varying temperatures, pressures, and stoichiometries with NOF to try to create NF3. A two-step process to create NF3 with SF4, NH3, and fluorine will also be performed.
The broader/commercial impact of the project will be the expansion of a market for nuclear waste by-products that is currently insufficient to utilize the existing supply of nuclear waste. By expanding the market, the potential to expand the nuclear power industry might be more palatable.
This Small Business Innovation Research (SBIR) Phase I project has significantly expanded the number of marketable compounds that can be converted from depleted uranium tetrafluoride (DUF4). DUF4 is produced by the reduction of depleted hexafluoride (DUF6), the largest and one of the most toxic waste components of the entire nuclear fuel cycle. While current technology could convert DUF4 into metallic fluorides, Pearlhill has developed new, environmentally and economically sound processes for the production of nonmetallic inorganic fluorides from uranium tetrafluoride (NIFUT). Pearlhill proved the feasibility of three NIFUT processes to produce commercially viable fluoride products; sulfur tetrafluoride (SF4) gas, sulfur hexafluoride (SF6) gas, and nitrogen trifluoride (NF3) gas. The results have been published in three U.S. patents, including US20110104032. The Department of Energy (DOE) currently has more than 500,000 tons of DUF6 in its inventory; meanwhile, four companies are planning to build new uranium enrichment plants. When these facilities are operational, an additional 27,000 tons of DUF6 waste will be added annually to the inventory. In order to decommission the entire DUF6 inventory, there is need to create new processes for the commercial production of high-value fluorine products from DUF6/DUF4 including a variety of metallic and non-metallic inorganic fluoride compounds, which can be absorbed into current markets. A mix of high-value fluoride products is needed to minimize flooding any single fluoride market. Market demand for metallic fluoride products can absorb only about 10 % of the potential metallic fluoride gas products that could be created from the annual ongoing enrichment process; hence there is a pressing need to increase the number of markets for fluoride products created from DUF6. Pearlhill’s innovative NIFUT process has addressed this need, and has proven that three fluoride products - SF4, SF6, and NF3 - can be produced at a significant cost advantage in the current marketplace. The transformations are shown in the attached x-Ray diffraction (XRD) patterns.
