Abstract: An system for emptying at least one reservoir containing a pressurized fluid, including, for each reservoir, a vent for discharging the fluid out of the reservoir and a discharge valve for connecting the reservoir to the vent, the emptying system additionally including, for each discharge valve, a return member for returning the discharge valve to its closed configuration, and a fluid control system for controlling the movement of each discharge valve to its open configuration by action of an operating fluid on the discharge valve, the control system including an operating station arranged outside a danger zone around each reservoir, and, for each discharge valve, a fluid pipe fluidically connecting the operating station to the discharge valve, the operating station including at least one reversible free connection for connecting to each fluid pipe of a device for supplying the control system with operating fluid.

Abstract: An apparatus (1) for thermal denitration of a uranyl nitrate hydrate to uranium trioxide UO3. The apparatus (1) comprises a burner (114) and a reaction chamber (110) configured to carry out thermal denitration of uranyl nitrate hydrate and to form uranium trioxide UO3 in the form of particles. The apparatus also comprises a separating chamber (120) suitable for separating UO3 particles from the gases resulting from the thermal denitration carried out in the reaction chamber (110), and at least one filter (130) configured for purifying the gases. The separating chamber (120) is a decanting chamber into which the reaction chamber (110) directly opens out. The filter (130) is capable of performing the separation at a temperature greater than or equal to 350° C. The invention also relates to use of such an apparatus, to a thermal denitration process and to UO3 particles obtained by such a process.

Abstract: The invention relates to a smoothing tool (3) configured for smoothing glass frit in a radioactive environment, in an induction-melting cold crucible. Smoothing tool (3) comprising a rod (30), a grid (50) configured to be in contact with glass frit (7) to be smoothed, and at least one vibrator (37, 55, 56) configured to make the grid (50) vibrate. The grid (50) is mechanically connected to the rod (30).

Abstract: A method for detecting leakage of a reducing fluid throughout an electrolyte membrane of an electrochemical cell is provided. The method includes the following consecutive steps: supplying the cell with anode and cathode streams; brisk and controlled variation of at least one of the following parameters: the pressure of the anode stream in the anode channel, the pressure of the cathode stream in the cathode channel, the flow rate of the anode stream into the anode channel, the flow rate of the cathode stream into the cathode channel, and the strength of the current exchanged between the two sides of the membrane; measurement of a first reducing fluid concentration in a first stream, including the cathode stream leaving the cathode channel; and deducing the presence or absence of leakage on the basis of the variation in the first measured concentration of reducing fluid over time. A corresponding fuel cell system is also provided.

Abstract: A method for controlling a pressurized water nuclear reactor is provided, including core producing thermal power, sensors for acquiring the mean temperature of the primary coolant and for calculating the thermal power, actuators for controlling the axial distribution of power, the control method including: a first control phase for controlling the reactor during normal operation by controlling the mean temperature of the primary coolant so as to make it correspond to a reference temperature profile (Pref) dependent on the thermal power of the reactor; and a second control phase, referred to as stretchout, that occurs after normal operation of the reactor in order to control the reactor in stretchout by controlling the axial distribution of power, the mean temperature varying freely in a temperature range delimited by an upper limit and a lower limit.

Abstract: A method for inspecting a surface (12) of a piece of nuclear power plant equipment includes scanning the surface (12) with an acquisition field (20) of a matrix array camera (14). The acquisition field (20) moves relative to the surface (12) at a movement speed. The method also includes acquiring, by means of the matrix array camera (14), an image (22) of the acquisition field (20), with a certain acquisition frequency. Each image (22) includes a first number of lines of pixels. The method also includes extracting, from each image (22), a first set of lines, the first set comprising a second number of continuous lines of pixels, the second number being between 2 and the first number; and constituting a final image (32) of the surface (12) by juxtaposing the lines extracted from each image (22). The movement speed, the acquisition frequency, the first number of lines and the second number of lines are chosen such that the final image (32) covers the entire surface (12) without interruption.

Abstract: A spacer for an electrolyzer cell of substantially annular shape comprises: a peripheral part having two parallel principal faces opposite each other, the distance separating the two principal faces defining a thickness of the spacer, and an internal part having a thickness strictly less than the thickness of the spacer, the peripheral part and the internal part being in one piece and connected to each other forming an internal annular shoulder so that the internal part has a substantially annular intermediate face extending in a plane parallel to the two principal faces of the peripheral part and situated between the two principal faces.

Abstract: An assembly for acting on the outer surface of a tube, and corresponding method are provided. The assembly includes a carrier; at least one inspection or maintenance tool; the carrier includes at least one rolling body; an actuator. The carrier further includes a device for connecting the carrier to the tube, arranged so that the tube absorbs at least 50% of the weight of the carrier and the tool.

Abstract: An electrical system includes a stack (3) of electrochemical cells (5), a power converter (9) electrically connected to the stack (3), a voltage comparator (7) for comparing the voltage at the terminals of at least one group of at least one electrochemical cell (5) of the stack (3) to a threshold voltage, and a control module (11) for controlling the converter (9). The control module (11) includes a generator (74) for generating a control instruction for controlling the converter (9) and a transmission member (76) for transmitting the control instruction to the converter (9). The voltage comparator (7) is suitable for transmitting a signal to the transmission member (76).

Abstract: A packing seal is provided for a system for sealing the shaft of a primary motor-driven pump unit of a nuclear reactor, intended to ensure sealing between the primary circuit and the atmosphere. The packing seal including a rotary active surface and a floating active surface, in which a face of the floating active surface and/or the rotary active surface is micro- or nano-structured by an array of holes or pillars, each hole or pillar having lateral dimensions and a height of between 10 nm and 5 ?m, the distance between two consecutive holes or pillars being between 10 nm and 5 ?m.

Abstract: A vibration-inhibiting bar is provided that is interposed between bends of the tubes of two adjacent banks of tubes of a U tube bundle of a steam generator and includes at least one internal element, referred to as a damping element, designed to mechanically damp the vibrations of the tubes; and at least one external element, referred to as percussion element, in contact with the damping element, the percussion element being designed to be in contact with the bends of the tubes of the bundle.

Abstract: A method for thermochemically treating a part while masking a portion and corresponding mask are provided. The method includes the steps of providing a mask comprising a body with a seat, at least a deformable sealing washer located in the seat, and a tightening bushing, the body having a cavity, placing a first portion of the part in the cavity, a second portion of the part being located in a passage in the sealing washer, and a third portion of the part being located outside the mask, moving the tightening bushing to its tightened position so that the sealing washer is deformed and applied against the second portion of the part, and applying a thermochemical treatment to the third portion of the part.

Abstract: A method is for producing seals on faces of electrochemical reactor components intended to be stacked in order to form an electrochemical reactor Each component is in the form of a plate and having a first face and an opposing second face. The first face is designed to receive a first seal and the second face is designed to receive a second seal. The method includes shaping the first seals on the first faces of the components, the first seals being at least partially polymerized; depositing the second seals on the second face of the components; and shaping the second seals by compressing a stack formed from the components alternating with molding plates.

Abstract: A circuit arrangement, in particular for a safety I&C system of a nuclear power plant, keeps a proven diagram-centric project-specific engineering approach known from CPU-based systems while reaping the benefits of FPGA technology. To this end, the circuit arrangement includes: a generic FPGA with a plurality of logic blocks, and at least one dedicated PLD which operates as an application-specific switch-matrix for the logic blocks.

Abstract: An air duct for a wind power plant is configured to guide air along a circumference of a supporting structure, in particular a tower, of the wind power plant. The wind power plant also includes an air guide and provides methods of manufacturing the air guide for the wind power plant and retrofitting the wind power plant with the air guide.

Abstract: A field programmable gate array comprising: plurality of functional blocks at least one of the functional blocks comprising at least one function, at least one of the functions using a parameter, wherein the functional blocks are adapted to perform the at least one function in a calculation phase; a data conveyor comprising a plurality of data slots, wherein each functional block is, in a data transfer phase, adapted to receive input data from one or more predefined first slots and/or to provide output data into one or more predefined second slots; and a configuration circuit adapted to configure the parameter for the at least function using the parameter and to define the one or more first slots and/or the one or more second slots for at least one functional block, wherein the field programmable gate array is adapted to cyclically repeat the data transfer phase and calculation phase.

Abstract: An assembly is provided that includes a device for locking tubes in position relative to one another, with at least a first arm, a locking axle having a plurality of bearing surfaces, the locking axle being movable between a position locking the tubes each between one of said bearing surfaces and the first arm, and a released position, in which the tube segments are free.

Abstract: An insertion assembly (1) includes a frame (11), having a longitudinal passage (13) for the thermocouple (3); a device (15) for blocking the pipe (5) in position relative to the frame (11); a device (17) for guiding the thermocouple along the passage (13); and a device (19) for driving the thermocouple (3). The driving device (19) includes at least a first drive belt (21) having a first longitudinal segment (25) pressed against the thermocouple (3), and a motor member driving said first segment (25) of the first belt (21) longitudinally relative to the frame (11).

Abstract: The present invention relates to a passive shutdown sealing device (20) for a reactor coolant pump unit comprising: a split sealing ring (23) having an inactivated position in which a leakage flow is permitted and an activated position in which said ring stops said leakage flow; at least one piston (22) designed to position said split sealing ring (23) in its activated position; locking/unlocking means (25) designed to lock said at least one piston (22) in its inactivated position when the temperature of said locking/unlocking means is below a temperature threshold and to release said at least one piston (22) when the temperature of said locking/unlocking means is above said temperature threshold; elastic means (24) designed to move said at least one piston (22) when said piston is released, so as to position said sealing ring (23) in its activated position.

Abstract: A method for simulating the flow of a fluid in a vessel of a nuclear reactor is provided. The nuclear reactor includes the vessel and a core inside the vessel, the core including nuclear fuel assemblies, each one extending in an axial direction, including nuclear fuel rods and a grid for maintaining the rods, and being spaced apart from another by a clearance between the grids in a transverse direction. This method for simulating a fluid flow in the vessel of a nuclear reactor includes determining of head loss coefficients in the core, and computing the fluid pressure and speed component(s) in the core using the equation: ?P=?K×V where P is the component of the fluid pressure, K is a matrix including the determined head loss coefficients, and V is a vector including the fluid speed component(s).