A High Temperature Isotopic Exchange (HITEX) process has been developed for processing of fusion fuel streams. The design has advantages over previous systems which have been based on catalytic oxidation or decomposition of impurities, since it eliminates the need for impurity oxidation and electrolysis of DTO, and does not rely on complicated catalytic decomposition reactions. A conceptual flowsheet of complete HITEX-based fuel processing system is described. Testing of the HITEX reactor is underway with deuterated impurities. Details of the experimental HITEX test loop are reported in this paper, and the test loop is compared to a HITEX design recently proposed for ITER (International Thermonuclear Experimental Reactor).