Uranium tetrafluoride, UF4, and thorium tetrafluoride, ThF4, can be used as fuels in molten salt reactors. For the molten salt reactor design and safety analysis, it is essential to know the thermodynamic properties o...Uranium tetrafluoride, UF4, and thorium tetrafluoride, ThF4, can be used as fuels in molten salt reactors. For the molten salt reactor design and safety analysis, it is essential to know the thermodynamic properties of the UF4 and ThF4 materials. However, the experimental data for UF4 and ThF4 P-V-T are scarce in literature. Under this circumstance prediction of the thermodynamic properties can be supported by theoretical calculations to remedy missing experimental data. Within this paper the Song, Mason and lhm＇s equation of state with modification of Tao and Mason, originally derived for spherical and molecular fluids, is applied for fluid UF4 and ThF4 based on the available experimental data. The equation of state is based on statistical mechanical perturbation theory with the perturbation scheme of Weeks, Chandler, and Andresen. The prediction of constants applied in the equation of state is based on the work of Boushehri et al. using data for heat of vaporization and liquid density at the triple point. The calculation of the heat of vaporization applies the ＂sigma＂ method reported by Darken et al. with the vapour pressure data and heat capacities of liquid and vapour of UF4 and ThF4. Finally an extra correction term for the vapour pressure is introduced into the new equation of state. The results show that this equation of state agrees reasonably well with the available experimental data. It can be expected that this equation of state can be applied also for conditions where experimental data are currently missing.展开更多
文摘Uranium tetrafluoride, UF4, and thorium tetrafluoride, ThF4, can be used as fuels in molten salt reactors. For the molten salt reactor design and safety analysis, it is essential to know the thermodynamic properties of the UF4 and ThF4 materials. However, the experimental data for UF4 and ThF4 P-V-T are scarce in literature. Under this circumstance prediction of the thermodynamic properties can be supported by theoretical calculations to remedy missing experimental data. Within this paper the Song, Mason and lhm＇s equation of state with modification of Tao and Mason, originally derived for spherical and molecular fluids, is applied for fluid UF4 and ThF4 based on the available experimental data. The equation of state is based on statistical mechanical perturbation theory with the perturbation scheme of Weeks, Chandler, and Andresen. The prediction of constants applied in the equation of state is based on the work of Boushehri et al. using data for heat of vaporization and liquid density at the triple point. The calculation of the heat of vaporization applies the ＂sigma＂ method reported by Darken et al. with the vapour pressure data and heat capacities of liquid and vapour of UF4 and ThF4. Finally an extra correction term for the vapour pressure is introduced into the new equation of state. The results show that this equation of state agrees reasonably well with the available experimental data. It can be expected that this equation of state can be applied also for conditions where experimental data are currently missing.
