The CECE process with AECL hydrophobic catalyst is ideally suited for extracting tritium from water because of its high separation factor and mild operating conditions. A simple linear expression that relates the overall rate constant (Kya) to the inverse of the equilibrium slope (m) for H2/H2O isotope exchange was developed from the two-film mass transfer model. Laboratory and pilot data were used to demonstrate the applicability of this simple relationship which allows reaction rates for any pair of hydrogen isotope species at any given concentration to be predicted from rate data of any other isotope pair and/or concentration range. This approach was used to design a hypothetical CECE plant for concentrating tritiated light water to 100 Ci/L (3.7 TBq/L) to give a 250-fold reduction in waste volume.