Fuel clean-up system

The feasibility of a permeation process using a palladium-silver alloy membrane, to separate deuterium and tritium from fusion reactor gaseous wastes needs demonstration owing to poisoning effects of impurities. A parametric investigation of the poisoning by the most important expected gaseous impurities (CO, CO2 and CH4) is carried out with the loop PALLAS, in function of membrane temperature (100 to 4500C), H2 pressure (0.3 to 14 kPa) and impurity concentration (0.2 to 9.5 vol. %). The poisoning effect of CO is a concern for the process while CO2 and CH4 appear to have no practical effect on the permeation rate. Depending on CO concentration optimal operating temperatures of the membrane should lie between 250 and 3750C limits