A design study of advanced hydrogen isotope separation system for ITER

A preliminary improved design study of the cryogenic distillation hydrogen isotope separation system (ISS) for the fuel cycle of the ITER-FEAT, a fusi on experimental reactor, was carried out based on the substantial reduction of hydrogen flow to the ISS resulting from the scale reduction from the fo rmer design for the FDR-ITER. In this study, a four-column cascade was prop osed considering the 450 seconds burn / 1350 seconds dwell operation scenar io of ITER-FEAT instead of the present five-column cascade design of the FD R-ITER. This proposed cascade is found to be effective in all operation pha ses. The impact of the optional 3000 seconds burn / 9000 seconds dwell oper ation scenario on the present design is also discussed in this paper. Triti um concentration in the released hydrogen stream into environment must alwa ys be controlled to be lower than the regulation limit for stack release, a nd the two-column system for treatment of this flow is found to be effectiv e for meeting this requirement.