Tritium Retention in Carbon Dust

This presentation describes experiments to investigate the sorption of tritium on carbon dust of different particle sizes and specific surface areas. The conditions of exposure were determined at the first wall of the tokamak. These conditions include low tritium pressures and depending on the operation phase, temperatures varying between 25°C and 1000°C. The simulation of these conditions inside an exposure chamber were necessary in order to design and construct a specific exposure device that could be adapted to these unusual conditions. Initial sorption data were obtained for carbon dust derived from a JET first-wall tile. The amount of tritium sorbed into or onto the carbon dust is between 0.1 and 10 mg T per kg C for a 24 hour-exposure duration. It increases with dust temperature. Other determinations, dealing particularly on the influence of exposure duration, are required to interpret this initial data.