The exhaust plasma processing plant, proposed a few years ago as an alternative to the Tritium Systems Test Assembly plant in operation at Los Alamos National Laboratory, required further research in such areas as a low liquid inventory electrolytic cell and the types of separator or membrane resistant to beta radiation. Moreover, it was suggested that the value of the separation factors among H2, D2, and T2 should be checked during electrolysis at high D2O concentration in an alkaline medium by using different materials for the cathode. The results of experimental work carried out in these directions have shown the feasibility of the process, although some improvements can still be made in the optimization of the separators and in the design of the cell. The research carried out at the Joint Research Centre, Ispra, Italy, with support from other institutes, is described.