Hydrogen transport in molten salt Flinak measured by solid electrolyte sensors with Pd electrode

The transport of hydrogen (H2) in Flinak was investigated using hydrogen sensor made of proton conductive solid electrolyte. The test in Flinak was performed after the validity of the sensor was checked in the test in Ar–H2 gas mixture with known hydrogen partial pressure. The sensor showed stable output in the Flinak at homogeneous temperature condition. The electromotive force (EMF) of the sensor agreed with theoretically estimated EMF. The sensor however showed the EMF much different from the theoretically estimated EMF when there was temperature difference between the free surface and the immersed sensor position. The temperature dependence of the Henry's law which controlled the hydrogen transport in Flinak was investigated from the sensor EMF. It was indicated that the Henry's constant for H2 in Flinak had the negative temperature dependence, which agrees with the previous study.