Abstract: An electrolyzer for high temperature electrolysis capable of operating in an allothermal mode including an enclosure, at least one electrolysis plate (8) including an anode and a cathode in combination and means for heating an active fluid intended to undergo a high temperature electrolysis, characterized in that the enclosure is capable of maintaining an electrolyte bath under high or very high pressure of several tens of bars, in that said heating means ( 10) are positioned in the enclosure and use a heat transfer fluid.

Abstract: An electrolyser for high-temperature electrolysis configured to operate in an allothermal mode, including an enclosure configured to maintain an electrolytic bath under high or very high pressure of several tens of bars, in which at least one electrolysis plate is arranged, and a heater internal to the enclosure. The electrolysis plate includes a plurality of electrolysis cells lying side by side in substantially one same plane, each electrolysis cell including an anode and a cathode. The heater uses a heat-carrier fluid.

Abstract: An electrolyser for high-temperature electrolysis configured to operate in an allothermal mode, including an enclosure configured to maintain an electrolytic bath under high or very high pressure of several tens of bars, in which at least one electrolysis plate is arranged, and a heater internal to the enclosure. The electrolysis plate includes a plurality of electrolysis cells lying side by side in substantially one same plane, each electrolysis cell including an anode and a cathode. The heater uses a heat-carrier fluid.

Abstract: An electrolyzer for high temperature electrolysis capable of operating in an allothermal mode including an enclosure, at least one electrolysis plate (8) including an anode and a cathode in combination and means for heating an active fluid intended to undergo a high temperature electrolysis, characterized in that the enclosure is capable of maintaining an electrolyte bath under high or very high pressure of several tens of bars, in that said heating means (10) are positioned in the enclosure and use a heat transfer fluid.

Abstract: A single piece fuel element and fast spectrum boiling water reactor using such a single piece fuel element. The single piece fuel element is formed from coated fissile particles embedded in a matrix made from a material such as SiC that is inert to all fissile and fertile heavy nuclei and to the coolant fluid circulating in and around this element. Furthermore, the fuel element includes parallel plates delimiting spaces between them. A ratio between the thickness of the plates and the width of the spaces is set so that the fuel element can be put in fast spectrum or thermal spectrum at will. An application of the single piece fuel element to a fast spectrum boiling water nuclear reactor operating with natural circulation in which the above mentioned ratio is approximately equal to 1 enables a high consumption of plutonium.

Abstract: Single piece fuel element and fast spectrum boiling water reactor using elements of this type.

Abstract: Fuel element and gas-cooled nuclear reactor using this type of fuel elements.

Abstract: A method for controlling heat exchange in a nuclear reactor. The reactor contains at least one thermal valve, at least one heat exchanger having a coolant flowing therein, with the heat exchanger being immersed in a pool containing a fluid. The heat exchanger is confined by a container having an upper part with an opening therein and a lower part having means for introducing the fluid through such lower part as well as means for partially or totally opening or closing said opening in the upper part and means for partially or totally opening or closing opening in the lower part. The method comprises the steps of closing the opening in the upper part of the container to thereby vaporize said fluid, in order to cause a cessation of heat exchange between the coolant and the fluid; and opening the opening in the upper part of the container to thereby cause the fluid to be heated and to rise by convection, thereby permitting heat exchange to occur between the coolant and the fluid.

Abstract: The injector (B) designed specifically to supply a steam generator (G) with water at high pressure when necessary, is supplied by steam that may originate from the generator itself, and by pressurized water from an ejector (C) supplied during the start up phase by a water circuit (D) pressurized by steam, and during the steady state phase, by an extraction circuit (R) connected on the downstream side of the injector. This device entrains water originating from a tank at low pressure (73) into injector (B), to pressurize it at a pressure exceeding the steam pressure.Application to safety devices in nuclear power stations.

Abstract: Internal condenser system for discharging vapor from a circuit into a tank or pool to reduce pressure in said circuit.The internal condensation conduit (47) comprises a diaphragm (52) just upstream of a cold liquid feed orifice (55); the jet of vapor passing through orifice (53) of the diaphragm creates a zone of significantly negative pressure around this jet and downstream of the diaphragm causing cold liquid to be sucked up. This causes the vapor to condense in the mixing chamber (56).One possible application relates to primary circuits of a nuclear reactor.

Abstract: Vaporizing device connected to a cooling circuit. In particular, it includes a receptacle (28) traversed by heat exchange tubes (26) which unite two pipes connected to a hot branch (3) and a cold branch (4) of the circuit. A vapor reject pipe (10) is open to engage vaporization; the circulation of hot water in the heat exchange tubes (26) drives vaporization of the liquid contained in the receptacle (28) whose feeding with liquid is ensured by a pipe (23) linked to the pipe (21) and comprising a stop valve (24) and a flow reducer (25).