Experimental validation of a method for performance monitoring of the front-end permeators in the TEP system of ITER

The reference process for the Tokamak Exhaust Processing (TEP) system of ITER is called CAPER and comprises three different, consecutive steps to recover hydrogen isotopes at highest purity for direct transfer to the cryogenic isotope separation system (ISS). The CAPER process was developed at the Tritium Laboratory Karlsruhe (TLK) and employs a palladium/silver permeator battery as the 1st step to separate more than 95% of the un-burnt deuterium/tritium fuel from impurities like helium, hydrocarbons and water. These so-called front-end permeators have a capacity of about 80 mol h−1/1 m2 effective surface area if operated under conditions currently specified for ITER. ont-end permeators of ITER should all the time be operated such that coking of the permeation membranes by hydrocarbon cracking is avoided, since this process lead to a reduction of the effective surface area and therefore to a reduction of the performance of the component. At TLK a method to measure the actual performance of a technical permeator has been developed. This method has been successfully tested with the experimental facility for the demonstration of the CAPER process at TLK and appears feasible for the TEP system of ITER.