(GRS 563) Development of Experimental Electrochemistry-based Methods for the Study of Redox-Processes of Uranium in Brine Solutions - EDUKEM
The joint research project EDUKEM aims the development of measurement techniques required for the generation of precise thermodynamic data of uranium species in near saturated salt solutions. In this report, an attempt to go beyond the classic dissolution experiments by the implementation of precise redox-type measurements for the uranium system is presented. This electrochemistry-based method requires the generation of new approaches to determine the diffusion potential and the electrode reaction path, generally disregarded in dilute systems and simple redox reactions. The first part of this work deals with the innovative use of electrochemical impedance and time domain reflectometry techniques for measuring the diffusion potential in concentrated electrolytes. The second part refers to the evaluation of the electrode reaction path for the system U(VI)/U(IV) by systematic potentiometric and spectrometric experiments. This work sets the basis for the application of the redox technique in the actinide chemistry.