Tritiated water is produced in tritium plants in a wide range of activity. This paper presents bipolar electrolysis, an electrochemical process that can be used for isotopic enrichment of tritiated water. After having described the principle of the process and its application to isotopic separation, we simulate the working of an operational cell considering both weakly (500 Ci/L, 1.85•1013 Bq/L) and highly active (100,000 Ci/L, 3.70•1015 Bq/L) tritiated water. In both cases the treatment leads to negligible gaseous tritium reject.