Measurement of the Kinematic Viscosity of Molar Melt 73LiF–27BeF 2 and Influence of Cerium Trifluoride and Zirconium Tetrafluoride Additives on Viscosity

In validating the concept of a molten-salt nuclear reactor for incinerating transuranium elements from spent nuclear fuel of light-water reactors, experimental data on the kinematic viscosity of melt with the molar composition 73LiF–27BeF2 were obtained in the range 882–1172 K. The influence of cerium trichloride and zirconium trifluoride as additives on the viscosity was investigated. It is shown that for all compositions the obtained viscosity is described by an exponential function of the reciprocal of absolute temperature. The parameters of this function are determined for each composition. It was found that the addition of cerium trifluoride in the amount 1 mol.% to the initial composition lowers viscosity at low temperature. Subsequent addition of zirconium tetrafluoride appreciably lowers the liquidus temperature.