The most common basic process of air detritiation, which employs oxidation of tritiated gases in a catalytic recombiner and subsequent collection ofHTO on molecular sieve dryers, can also be used for a large-scale detritiation system for the next-step deuterium-tritium fusion device. Performance, economy, and reliability can be improved by modifying the design of basic elements, i.e., the recombiners and molecular sieve dryers, and by rearranging them in a system permitting multiple process path choices for optimum performance depending on demand. These improvements should result in a system that is (a) free of secondary tritium release by permeation; (b) economical, with <1 kW power required in a ready-to-operate “hot standby” condition; (c) capable of reducing inlet humidity of the order of 10000 ppm (volume) to 0.01 ppm at the outlet by using two adsorber stages in series; and (d) capable of providing the best starting condition for water processing: little or no dilution by H2O from isotopic swamping due to the use of two adsorber stages. The system detritiation factor is defined and discussed, and the overriding importance of high water retention efficiency is demonstrated.