Patent Number: 051026180
Section: claims

1. A vapour phase catalytic exchange reactor for use in the separation of tritium from tritiated water by reacting the water as superheated steam with tritium-lean hydrogen and separating the reaction products thereof, the reactor comprising a superheater section, a catalytic reactor section and a condenser section, said sections being interconnected in series, characterized in that said sections are integrated into a unitary casing structure, said casing structure providing means for admitting a mixture of tritiated steam and tritium-lean hydrogen to the superheater section, internal support means for supporting a catalyst in the catalytic reactor section, first outlet means connected to the condenser section for draining condensate therefrom, and second outlet means connected to the condenser section for venting hydrogen gas therefrom. 2. A vapour phase catalytic exchange reactor according to claim 1, further comprising an evaporator section, said evaporator section being integrated into said casing structure adjacent to the superheater section and providing first and second inlet means for feeding the tritiated heavy water and the tritium-lean hydrogen thereto. 3. A vapour phase catalytic exchange reactor according to claim 2, said evaporator section including a mixing chamber from which the mixture of tritiated steam and tritium-lean hydrogen pass to the superheater. 4. A vapour phase catalytic exchange reactor according to claim 1, wherein the casing structure comprises a first casing section comprising an elongate cylinder having a flanged opening at each end, the openings being closed by respective second and third flanged casing sections secured to the end flanges of the cylinder, the interconnected sections forming a unitary pressure vessel. 5. A vapour phase catalytic exchange reactor according to claim 2, wherein the casing structure comprises a first casing section comprising an elongate cylinder having a flanged opening at each end, and respective second and third flanged casing sections secured to the end flanges of the cylinder and forming therewith a unitary pressure vessel, said third flanged casing section housing said evaporator section and said first casing section housing the superheater section, the catalytic reactor section, and the condenser section. 6. A multistage tritium separation plant comprising a plurality of reactors as claimed in claim 1 interconnected to effect countercurrent flow of the water and hydrogen from stage to stage with co-current contact in the catalytic reactor section of each stage, wherein the casing structure of each reactor is a vertically oriented, elongate pressure vessel, the superheater, catalytic reactor and condenser sections thereof being in substantial vertical alignment. 7. A multistage tritium separation plant according to claim 6, wherein the casing structure of each reactor comprises a first casing section comprising an elongate cylinder having a flanged opening at each end, the openings being closed by respective second and third flanged casing sections secured to the end flanges of the cylinder. 8. A multistage tritium separation plant according to claim 7, wherein each reactor further comprises an evaporator section integrated into the casing structure, the interconnected sections forming a unitary pressure vessel. 9. A multistage tritium separation plant according to claim 7, wherein the reactor of the first stage is connected to receive tritiated water from an external supply and wherein the reactor of each subsequent stage includes an evaporator section integrated into the casing structure thereof. 10. A multistage tritium separation plant according to claim 8 or claim 9, wherein the interconnections between the reactors provide for gravitational flow of condensate from the condenser section of each stage to the evaporator section of the adjacent subsequent stage.