XAS provides atom-specific structural and chemical information. It is sensitive to the oxidation state of ions and their local environment at concentrations down to a few ppm. Since XAS is likely impossible to implement in a working reactor, we conducted simultaneous XAS and ECS measurements of corrosion in molten salt in a lab at MSR operating temperatures. Our developments of simultaneous measurements will enable high-fidelity monitoring of the salt chemistry of operating MSRs by reinforcing electrochemical methods. In addition, performing XAS during electrochemical measurements detects corrosion of the electrodes which prevents potential misinterpretation in the electrochemical spectra. These results are important to ensure the stability of the electrodes and reliability of results. Moreover, XAS is much better suited than ECS to probe the fundamental chemistry of impurities in molten salts at the atomic level.