In-situ measurements of molten salts pose difficult challenges. For example, optical techniques such as Raman, UV, or IR spectroscopy typically used for similar characterization require cells to be made out of optically transparent materials such as glass and quartz. These materials are not compatible with molten fluorides, which chemically attack them. Molten fluoride salts re-quire containers made from graphite, glassy carbon, boron nitride, and metal alloys. While ceramics are compatible with XAS, they are difficult to machine and seal; on the other hand, metals are not compatible with XAS and can themselves contribute corrosion products during measurements. Therefore, we developed an experimental apparatus for probing molten fluorides by XAS and ECS including a customized furnace and crystallized boron nitride (BN) cells that are optimized for use with hard XAS. The corrosion cell is designed to perform quantitative XAS measurements in conjunction with ECS and fluoride-based salts to validate and reinforce the low-resolution redox measurements. This apparatus, when employed at bright synchrotron facilities, can be utilized to determine the time-evolution and atomic structures of important corrosion processes in structural materials across relevant time scales (sub-minuteshours) and temperatures (460 °C to 750 °C) pertinent to MSR technology.