POST SERVICE EXAMINATION OF A TRITIUM PERMEATOR AND A TURBOMOLECULAR PUMP FROM THE CAPER FACILITY AT THE TRITIUM LABORATORY KARLSRUHE

摘要

After 8 years of operation at the CAPER facility at the Tritium Laboratory Karlsruhe, a permeator used to separate hydrogen species from processed gases ceased operation due to multiple heater failures. This was subjected to post service examination to find the cause of the failures. This paper describe the methods used to locate the failures in the heaters and the likely cause. It was also necessary to determine the tritium inventory embedded in the structure for safe disposal. Destructive examination, adapted from a full combustion technique, was used on sections of the permeator. A fine black powder deposit, presumed to be mostly carbon, coated the surfaces of the inlet section of the feed side. This powder contained nearly half of the tritium within the permeator. The likely source of the powder and the consequences for the operation and eventual decommissioning of the ITER Tritium Plant are discussed. A failed turbomolecular pump from CAPER was also examined. There was evidence of wear on the emergency support bearing, but more importantly, when the pump internals were exposed to the glove box atmosphere (dry air) large quantities of tritium were rapidly released, this despite the isotopic swamping before removal from the CAPER glove box. Significant uptake of tritium in electrical insulation was also found.