LONG-TERM PERMEATOR EXPERIMENT PETRA AT THE TRITIUM-LABORATORY-KARLSRUHE - COMMISSIONING TESTS WITH TRITIUM

During commissioning of the PETRA facility all components were tested singly and sequentially using hydrogen isotopes (incl, up to 1.3 g tri tium as DT) and relevant impurities. The operation of the facility in conjunction with the required infrastructure systems of the Tritium La boratory Karlsruhe (TLK) was also demonstrated. To characterize the PE TRA PdAg permeator hydrogen break-through curves for H-2, Da and DT as well as He break-through curves for various H-2/D-2/He gas mixtures w ere determined at 300 and 400 degrees C. A suitable method was develop ed to verify the mechanical integrity of the permeator during runs wit h tritium. The H-2 and D-2 permeation losses into the isolation vacuum of the permeator were quantified and compared with model calculations . Hydrogen permeation into the isolation vacuum could be kept at level s low enough to permit an undisturbed continuous operation of the perm eator using a ZrCo tritium storage vessel.All pumps and pump combinati ons were examined with respect to the achievable vacua and compression ratios employing relevant gases and their mixtures. Loop-integrated i nfrared analysis of high signal and background stability is used to ve rify the integrity of the permeator and to study the possible occurren ce of radiochemical reactions in the gas phase. It was shown that the ZrCo tritium storage vessel of the PETRA facility can be employed avan tageously for the handling of tritium when used in combination with a Normetex scroll pump (18 m(3)/h)/Siemens metal bellows double stage co mpressor pump sequence. With this combination it is possible to extrac t at < 320 degrees C > 98% of the hydrogen isotopes from the ZrCo stor age vessel with a) negligible permeation losses, b) without the danger of disproportionation of the intermetallic compound and c) with minim ization of the tritium inventory in the facility.