THE AQUEOUS SYNTHESIS OF UMoO6 AND ITS SIGNIFICANCE TO NUCLEAR FUEL

While investigating the thermodynamics of the U-Mo-O chemical system, it became necessary to synthesize a quantity of UMoO6. A novel aqueous method for the synthesis of UMoO6wasexplored as an alternative to conventional solid state synthesis.In this method, aqueous salts of molybdate (MoO42-) and uranyl (UO22+) are combined in a 1:1 ratioin order to precipitate a product that is characteristic of UMoO6. One attempt resulted in the formation of a mixed U-Mo oxide: Na8(UO2)24(MoO4)28. Full characterization of this novel compound, including definitive structural determination via single crystal X-ray diffraction (SC-XRD), is included herein. A second attempt formed a product resembling UMoO6. 1. Background The ability to model accurately nuclear fuel chemistry is highly valued by the nuclear industry. The fundamental bases of phase equilibrium nuclear fuel models arethermodynamic data, whichare the product of many years of experimentation and computational study. These data are found by first investigating individual chemical systems andare used to predict the chemical phase equilibrium of partially burned nuclear fuel for a given environmental condition