Capture and Isotopic Exchange Method for Water and Hydrogen Isotopes on Zeolite Catalysts up to Technical Scale for Pre-Study of Processing Highly Tritiated Water

Highly tritiated water (HTW) may be generated at ITER by various processes and, due to the excessive radio toxicity, the self-radiolysis and the exceedingly corrosive property of HTW, a potential hazard is associated with its storage and process. Therefore, the capture and exchange method for HTW utilizing Molecular Sieve Beds (MSB) was investigated in view of adsorption capacity, isotopic exchange performance and process parameters. For the MSB, different types of zeolite were selected. All zeolite materials were additionally platinized. The following work comprised the selection of the most efficient zeolite candidate based on detailed parametric studies during the H₂/D₂O laboratory scale exchange experiments (~25 g zeolite per bed) at the Tritium Laboratory Karlsruhe (TLK). For the zeolite, characterization analytical techniques such as Infrared Spectroscopy, Thermogravimetry and online mass spectrometry were implemented. Followed by further investigation of the selected zeolite catalyst under full technical operation, a MSB (~22 kg zeolite) was processed with hydrogen flow rates up to 60 mol h^-1 and deuterated water loads up to 1.6 kg in view of later ITER processing of arising HTW.