Vaporization behaviour of the Molten Salt Fast Reactor fuel: The LiF-ThF4-UF4 system
A selected composition of the initial fuel of the Molten Salt Fast Reactor (MSFR) is assessed by differential
scanning calorimetry (DSC) for melting point determination and by Knudsen effusion mass spectrometry
(KEMS) for vaporization behaviour. Partial vapour pressures and thermodynamic activities of the MSFR
fuel mixture are discussed indicating departures from ideal behaviour, and further interpreted by phase
equilibria calculations. The boiling point of the mixture is obtained extrapolating vapour pressure
experimental results. New results on the vaporization behaviour of pure uranium tetrafluoride are
presented, together with the ionization potentials of UF4 by electron impact.