This work examines the thermochemistry of the chromium difluoride CrF2 corrosion product in the molten [Formula presented] fuel salt system. Through a combination of experimental investigations and thermodynamic modeling assessment, the study elucidates the thermodynamic properties, phase diagram equilibria, and overall thermodynamic behavior of CrF2 corrosion product, following dissolution from a structural material to the molten salt fuel environment. In this work, two different synthesis methods were developed for pure CrF2, further allowing to experimentally measure the phase equilibria in the [Formula presented], [Formula presented], and [Formula presented] systems. Then, thermodynamic models were developed using the CALPHAD method based on the quasichemical model in the quadruplet approximation.@en