There is a pressing worldwide need for research to develop specific sustainable spent fuel reprocessing technologies suitable for minimizing waste from next generation nuclear reactors, as well as for dealing with legacy waste fuel from old reactors - one such solution utilises molten salt reactors to reprocess spent nuclear fuel for re-use in closed loop reactor cycles. The authors are studying the reduction of depleted uranium oxides (and other analogue materials) in a lithium/potassium chloride eutectic salt. In order to explore the mechanism of the reduction process in-situ, we propose to use neutron diffraction at Engin-X coupled with chrono-amperometry - the authors intend to deduce the kinetics and exact electrochemical reduction sequences of these processes which have significant potential impact on the nuclear industry.