Tritium is used as a fuel in nuclear fusion, and water detritiation is an important part of the overall fusion fuel cycle. This paper compares two competing technologies for an ITER-scale water detritiation reactor, namely, the advanced water distillation (AWD) and combined electrolysis and catalytic exchange (CECE) processes. The processes are compared in terms of equipment size and footprint, energy demand, isotope separation characteristics, safety, and technology readiness level. An important technical concern discussed is management of deuterium accumulation since deuterium is enriched along with tritium and D-T separation is inherently more difficult than H-T separation. Interfacing with a downstream isotope separation system is also discussed.