Fluorination of UO2, La2O3, and Y2O3 using ZrF4

Due to its high affinity towards oxygen, zirconium fluoride can fluorinate oxides found in used nuclear fuel while producing zirconium oxide. This study accomplished this using a lithium fluoride, sodium fluoride, zirconium fluoride (26-37-37 mol%) molten salt known as FLiNaZr with a melting point of 709K. The high concentration of zirconium fluoride in the FLiNaZr molten salt also prevents the formation of oxyfluorides during this process. The maximum reaction rates of FLiNaZr with yttrium oxide, lanthanum oxide, and uranium oxide were studied and analyzed. These rates were normalized by the surface area of the oxide piece exposed to the salt, giving a value that can be easily scaled to larger systems and samples. Tests were run at 773K, 823K, 873K, and 923K to determine the temperature's impact on the reaction rate.