Hydrogen enrichment by means of electrochemical hydrogen pump using proton-conducting ceramics for a tritium stack monitor

In order to develop a tritium monitor system with proton-conducting ceramics, the characteristics of a hydrogen pump with a CaZr0.9In0.1O3−α electrolyte were evaluated. Various methods were explored for attaching the platinum electrodes. Hydrogen enrichment characteristics of the simulated tritium monitoring system were investigated at 923 K and 2 V in a wet argon atmosphere with 19.5% oxygen concentration. Among all the electrodes tested, the maximum hydrogen evolution rate at the cathode was obtained by employing a pasted electrode and a plated electrode with a gold mesh as the anode and cathode, respectively. An evaluation of the hydrogen enrichment indicates that hydrogen could be enriched in a closed loop system of the simulated tritium monitor. The enrichment of hydrogen was found to be satisfactory. Based on these experimental results, the required electrode area for the proposed tritium monitor system was estimated to be 75 cm2.