2017 | AFC ACCOMPLISHMENTS 71 ment of 10 B to 11 B will have to be taken into consideration.The results presented here will serve as a basis for the assessment of the UO2-UBx fuel forms. Further high temperature evaluation of the thermophysical properties of this fuel are necessary to effectively map out its accident tolerant capabilities. [1] J. Fink, “Thermophysical proper- ties of uranium dioxide,” J. Nucl. Mater., vol. 279, no. 1, pp. 1–18, 2000. [2] J.T.White, “Report on the basic chemistry, microstructure and physical properties of high uranium density boride compounds,” 2015. [3] D. R. Fredrickson, M. G. Barner, R.D., Chasanov, R. L. Nuttall, R. Kleb, andW. N. Hubbard, “The Enthalpy of Uranium Diboride from 600 to 1500 ° K by Drop Calorimetry,” HighTemp. Sci. 1, vol. 80, pp. 373–380, 1969. [4] J.T.White and A.T. Nelson, “Thermal conductivity of UO2+x and U4O9-y,” J. Nucl. Mater., vol. 443, no. 1–3, pp. 342–350, 2013. Figure 3. Calculated thermal conductivity values as a function of temperature for UO2-UB2 composites (squares) together with reference thermal conductivity data on UO2 [1] and UB2 [2].