Abstract: A method is disclosed for heavy-water extraction from non-electrolytic hydrogen streams using a modified Combined Electrolysis and Catalytic Exchange-Heavy Water Process (CECE-HWP). The method comprises contacting feed water in a catalyst column with hydrogen gas originating partly from such non-electrolytic hydrogen stream and partly from an electrolytic hydrogen stream so as to enrich the feed water with deuterium extracted from both the non-electrolytic and electrolytic hydrogen gas, and passing the deuterium enriched water to an electrolyzer wherein the electrolytic hydrogen gas is generated and then fed through the catalyst column.

Abstract: Apparatus for upgrading and final enrichment of heavy water comprising means for contacting partially enriched heavy water feed in a catalyst column with hydrogen gas (essentially D.sub.2) originating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and means for passing the deuterium enriched water to the electrolysis cell.

Abstract: A method and apparatus for removing tritium from heavy water and light water comprising contacting tritiated feed water in a catalyst column in countercurrent flow with hydrogen gas originating from an electrolysis cell so as to enrich this feed water with tritium from the electrolytic hydrogen gas and passing the tritium enriched water to an electrolysis cell wherein the electrolytic hydrogen gas is generated and then fed upwards through the catalyst column. The tritium content of the hydrogen gas leaving the top of the enricher catalyst column is further reduced in a stripper column containing catalyst which transfers the tritium to a countercurrent flow of liquid water.

Abstract: A composite deuterium exchange process incorporating a catalytic exchange region and electrolytic cell region having an anode and cathode separated from each other by an electrolyte permeable diaphragm with liquid water and hydrogen gas being cycled through the two regions. It is preferred that the catalyst used in the catalytic exchange region is one that comprises at least one catalytically active metal selected from Group VIII of the periodic table and have a sealing coating directly thereon of waterproof (impermeable to liquid water) resin and are permeable to water vapor from the liquid water and hydrogen gas permeate the coating to contact the catalytically active metal thereby to exchange hydrogen isotopes, while the coating retards poisoning of the catalyst by liquid water.