Abstract: A reactor for use in the separation of tritium from tritiated water by the vapor phase catalytic exchange process comprises an evaporator section, a superheater section, a catalytic reactor section and a condenser section serially arranged within a common casing structure defining a unitary pressure vessel. In a multistage plant the reactors are interconnected to provide for countercurrent flow of the water and hydrogen gas from stage to stage, with co-current contact in the catalytic reactor section of each stage. By incorporating the components of each stage in a common casing structure, the external piping is minimized and the risk of leakage is reduced.

Abstract: A container for radioactive material includes therein a catalyst device for catalyzing the recombination of gaseous hydrogen and oxygen in the container to give water, e.g. in a storage vessel for radioactive material. The device comprises a substrate in the form of at least one metal member (e.g. stainless steel) carrying a thermally sprayed low surface area ceramic coating (e.g. plasma sprayed alumina) which carries a high surface area ceramic coating (e.g. alumina from a sol), which latter coating carries catalytically active material (e.g. Pt metal), the catalyst having an outer, hydrophobic gas permeable coating (e.g. polysiloxane) for preventing the catalytically active material from contacting water.

Abstract: An apparatus for the recombination of hydrogen and oxygen with the aid of a catalyst includes a vertically extending tube having end surfaces. A catalyst body is disposed in the tube. Stoppers close the end surfaces of the tube and open as a function of at least one parameter from the group consisting of pressure and temperature.

Abstract: An improved boiling water nuclear reactor and method for preventing intergranular stress crack corrosion in the recirculation line of the reactor system where recirculation line coolant water containing dissolved oxygen is diverted from the recirculation loop, hydrogen gas is introduced into the recirculation loop coolant water and the hydrogen-containing recirculation loop coolant water is contacted with a catalyst to enhance reaction of the hydrogen gas with the dissolved oxygen. The deoxygenated recirculation loop coolant water is then returned to the reactor vessel for passage through the core thereof. The hydrogen gas may be added in a stoichiometric amount to remove the dissolved oxygen or in a slight excess so as to suppress radiolysis in the reactor core.

Abstract: A catalytic igniter which can ignite a hydrogen-air mixture as lean as 5.5% hydrogen with induction times ranging from 20 s to 400 s, under conditions which may be present during a loss-of-liquid-coolant accident at a light water nuclear reactor comprises (a) a perforate catalytically active substrate, such as a platinum coated ceramic honeycomb or wire mesh screen, through which heated gases produced by oxidation of the mixture can freely flow and (b) a plurality of thin platinum wires mounted in a thermally conductive manner on the substrate and positioned thereon so as to be able to receive heat from the substrate and the heated gases while also in contact with unoxidized gases.

Abstract: In a system for disposing radioactive gaseous wastes in a nuclear power plant including a steam turbine and a main condenser connected thereto, a recombining unit is connected to the main condenser and includes a preheater for heating the radioactive gaseous wastes fed from the main condenser to a predetermined temperature and a recombiner for recombining into water vapor oxygen and hydrogen contained in the radioactive gaseous wastes passing through the preheater. A condenser is connected to the recombining unit for cooling the recombined water vapor contained in the radioactive gaseous wastes into condensed water and a hold-up device connected to the condenser for adsorbing and holding up the radioactive gaseous wastes with an adsorbing agent. The waste gas is discharged from a stack connected to the holdup device into atmosphere.

Abstract: In a method for the controlled removal of hydrogen released into the chambers of a nuclear reactor containment after a break of the primary cooling system, the hydrogen is contacted with an oxygen providing material stored in the containment which causes recombination of the hydrogen to H.sub.2 O in a controlled manner at least until the amount of the gas within the hydrogen chamber is below the ignition limit of a hydrogen oxygen gas mixture.

Abstract: An apparatus for isotope exchange reaction is used in an apparatus for removing tritium in heavy water-moderated nuclear reactors or heavy water production plants, and comprises a plurality of mist generators and a plurality of reactor columns, the mist generators and the reactor columns being alternately arranged and connected to one another successively in the alternate order. An ultra-sonic generator is provided each in the mist generators. A hydrophobic catalyst bed and a mist separator are provided each in the reactor columns. Water containing hydrogen isotopes to be removed is led into the mist generators to form mists. Mists of the water are supplied into the reactor columns together with hydrogen gas and isotope exchange reaction is carried out in the hydrophobic catalyst beds.