Thermodynamic and Spectroscopic Properties of Thorium-Uranium Oxo Fluorides using Ab Initio Chemistry

Abstract

Optical, IR-Raman, and X-Ray Absorption Spectra are calculated for the ThOUF_x^-(6-x) (x= 6-10) using ab initio Density Functional Theory (DFT) to facilitate the development of techniques for online spectroscopic techniques for monitoring fuel composition of Molten Salt Reactors. Geometric and IR calculations show good agreement with experimentally available data validating this model for use mixed actinide oxofluorides. Application of a mixed monitoring methodology employing vibrational, optical, and x-ray spectroscopy can be used to distinguish and measure the degree of speciation and formation of actinoid fluorides, and bridged oxidized actinoid species.