Application of thermonuclear fusion with deuterium for power generation may become a reality in the distant future. The recovery performances of deuterium from water-isotope mixture in various concentric-tube thermal diffusion columns, such as open, wired and rotated wired devices, have been compared with different flow-rate range operations. It was found that the operation in a concentric-tube column with a wire spiral inserted in the annular spacing and with tubes rotated in opposite directions, will reduce the remixing effect and enhance the cascading effect, respectively, resulting in improved performance. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.