Abstract: A method for simulating the fluid flow in a vessel of a nuclear reactor is provided. The reactor includes a core inside the vessel, the core including a lower plate, an upper plate and fuel assemblies extending between the plates, and having a volume axially delimited by first and second interfaces corresponding to the plates. The method includes computing, for the core volume, the fluid pressure and speed, from an initial value of the speed or pressure in the first interface and respectively in the second interface, and using the fluid mass, movement quantity and energy balance equations.

Abstract: A non-human-entry method for extracting a desired subsurface material such as ore, wherein an access hole is drilled from surface downwardly to the material, a high-pressure fluid injection tool is lowered with or after the drill string to the material and injected outwardly to disaggregate the material and form a cavity, and the material is optionally ground to a desired size by a drill bit or other means to enable suction up production tubing with a carrier fluid to the surface. The injection tool and grinding means are preferably part of an integrated bottom hole assembly at the lowermost end of a drill string, which may include surveying equipment to measure the cavity dimensions at intervals during target material disaggregation to allow fluid injection adjustment to seek to achieve a desired cavity geometry. Deck cementing is optionally employed for ground support.

Abstract: An ultrasound transducer is provided. The ultrasound transducer include at least one emitter made from a piezoelectric material, having first and second emitting surfaces opposite one another provided to emit first and second ultrasound beams. The transducer comprises at least first and second mirrors placed across from the first and second emitting surfaces, respectively, and configured so as to deflect back the first and second ultrasound beams by forming a reflected beam with a predetermined shape.

Abstract: A method is provided for operating a nuclear reactor. The method includes operating the nuclear reactor for at least one plutonium equilibrium cycle during which the core contains plutonium-equilibrium nuclear fuel assemblies; subsequently, operating the reactor for transition cycles, at least some of the plutonium-equilibrium nuclear fuel assemblies being progressively replaced with transition nuclear fuel assemblies and then with uranium-equilibrium nuclear fuel assemblies; and then operating the nuclear reactor for at least one uranium equilibrium cycle.

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 includes a rotary active surface and a floating active surface, and a face of the floating active surface and/or the rotary active surface is covered by a protective layer made from a material having surface energy greater than 30 mJ/m2 and an electron donor component less than 15 mJ/m2.

Abstract: The application relates to a method for testing a workpiece using ultrasound in a curved region of the surface of said workpiece, having the following steps: a plurality of ultrasonic signals are emitted from a plurality of transmitting positions into the workpiece a corresponding ultrasonic echo signal is received for each ultrasonic signal the ultrasonic echoes having amplitudes representing local maxima are determined for each transmitting position if an individual ultrasonic echo having an amplitude representing a local maximum was determined for a transmitting position in, the associated ultrasonic echo signal of said echo is selected if a plurality of ultrasonic echoes having an amplitude representing a local maximum were determined for a transmitting position, ultrasonic echo signals are selected if only an individual ultrasonic echo having an amplitude representing a local maximum was determined for an adjacent transmitting position at least the selected ultrasonic echo signals are evaluated.

Abstract: A methyl iodide adsorber, comprising a zeolite containing at least one iodide-adsorbing metal or a compound thereof, wherein the zeolite is a hydrophobic zeolite. Also, a use of the adsorber and a method for the adsorption of methyl iodide.

Abstract: A method for controlling a fuel cell (12) includes the following steps: measuring the fluid pressure in a first compartment from the anode and cathode compartments of the fuel cell (12); calculating a first target pressure for the fluid pressure in the second compartment of the fuel cell (12), the first target pressure depending on the fluid pressure measured in the first compartment; stabilizing the fluid pressure in the second compartment to the first target pressure; measuring the fluid pressure in the second compartment; calculating a second target pressure for the fluid pressure in the first compartment, the second target pressure depending on the fluid pressure measured in the second compartment; and stabilizing the fluid pressure in the first compartment at the second target pressure.

Abstract: A ventilation system for an operating space accessible to operators in a nuclear installation is intended to allow a supply of decontaminated fresh air for a period of a few hours in the event of serious accidents involving the release of radioactive activity. In particular, the component of radioactive inert gases in the fresh air supplied to the operating space should be as small as possible. For this purpose, the ventilation system has a supply air line that is guided from an external inlet to the operating space, and into which a first fan and a first inert gas adsorber column are connected. An exhaust air line is guided from the operating space to an external outlet, and into which a second fan and a second inert gas adsorber column are connected. A switching device is provided for interchanging the roles of the first and second inert gas adsorber columns.

Abstract: A hose or tube for transporting a gas specimen has an inner envelope, forming a diffusion barrier and containing a plurality of perforation holes, and an outer envelope, forming a diffusion layer and resting on the inner envelope. The object is to develop a hose or tube so as to ensure transport of a gas specimen over as great a distance as possible without substantial weakening of the concentration, and at the same time without impairing the ability of the gas to be detected to diffuse into the hose or tube. For this purpose, the outer envelope contains diffusion-inhibiting sealing zones on its inner surface, which zones overlap the perforation holes in the inner envelope.

Abstract: A treatment process for a zirconium alloy is provided. The process includes the following steps: a zirconium alloy ingot is prepared, the composition of which is: 0.40%?Nb?1.05%; traces?Sn?2%; (0.5Nb?0.25) %?Fe?0.50%; traces?Ni?0.10%; traces?(Cr+V) %?0.50%; traces?S?35 ppm; 600 ppm?O?2000 ppm, preferably 1200 ppm?O?1600 ppm; traces?Si?120 ppm; traces?C?150 ppm; the remaining being Zr and unavoidable impurities; the ingot undergoes at least one reheating and hot shaping step, and possibly a reheating and quenching step following a hot shaping step; optionally the hot-shaped ingot undergoes an annealing; the hot-shaped and possibly annealed ingot undergoes at least one cycle of cold rolling-annealing steps; the annealing of at least one of the cold rolling-annealing steps being performed at a temperature comprised between 600° C. and the lowest of either 700° C. or (710?20×Nb %)° C.

Abstract: A cladding tube for nuclear fuel made from metal and including concave dimples on its external surface. A nuclear fuel assembly includes at least a plurality of nuclear fuel rods provided with such cladding tubes. The cladding tube is advantageously manufactured by pilgrim rolling, the dimples being formed during the pilgrim rolling.

Abstract: A device and method for three-dimensional reconstruction of a scene by image analysis is provided. This device comprises an image acquisition device to capture images of the scene, an analysis device to calculate a three-dimensional reconstruction of the scene from at least one image of the scene taken by the image acquisition device, and a projection device to project a first light pattern and a second light pattern, which are complementary, on the examined scene, the first light pattern and the second light pattern being projected along separate projection axes forming a non-zero angle between them, so as to be superimposed while forming a uniform image with homogenous intensity in a projection plane.

Abstract: A method to activate U3O8 for conversion of this uranium oxide to hydrated UO4 via reaction with hydrogen peroxide H2O2, wherein the following successive steps are performed: a) an aqueous suspension is prepared containing a powder of U3O8 and hydrogen peroxide; b) the aqueous suspension containing a powder of U3O8 and hydrogen peroxide is contacted with ozone, whereby an aqueous suspension is obtained of a powder of activated U3O8; c) optionally the powder of activated U3O8 is separated from the aqueous suspension. A method to convert U3O8 to hydrated UO4 of formula UO4, nH2O where n is 2 or 4, comprising at least one step at which hydrogen peroxide H2O2 is added to the aqueous suspension of a powder of activated U3O8 obtained at the end of step b) of the activation method or to an aqueous suspension prepared by placing in suspension in water the powder of activated U3O8 obtained at the end of step c) of the activation method.

Abstract: A connecting device including a nut, a screw, a body having a bore for screwing the screw to the nut through the bore with the screw abutting an abutment surface of the body, a screw locking device for preventing loosening of the screw. According to one aspect of the invention, the locking device is adapted for axially retaining the screw into the body after unscrewing the screw.

Abstract: A hybrid shaft bearing, a wind generator comprising the hybrid shaft bearing, a use of the hybrid shaft bearing, and a method of operating the hybrid shaft bearing is provided. The hybrid shaft bearing comprises a hydrodynamic friction bearing and a rolling bearing. Both the hydrodynamic friction and rolling bearings cooperate with a support structure and rotatably support a shaft. The hydrodynamic friction bearing is a passive hydrodynamic bearing.

Abstract: A method for controlling the positions of a plurality of nuclear fuel assemblies (1) relative to an upper core plate (3) in a nuclear reactor core, the method including the following steps: choosing a reference point (13) in internals or in a reactor vessel; determining the positions of S-shaped holes of the nuclear fuel assemblies (1) relative to the reference point (13), each S-shaped hole being intended to cooperate with a corresponding centering pin of the upper core plate (3); acquiring the positions of the centering pins of the upper core plate (3) relative to the reference point (13); and comparing the positions of the S-shaped holes and the positions of the pins and deducing therefrom whether the nuclear fuel assemblies (1) are correctly positioned relative to the upper core plate (3).

Abstract: A tool for handling a long and heavy object, in particular a wind turbine rotor blade, includes a clamping unit which can be fixed to the rotor blade. The clamping unit has a first clamp and a second clamp spaced from the first clamp with respect to a longitudinal direction of the object. A first rod unit is rotatably coupled to the first clamp of the clamping unit at a first coupling site is also and coupled to a traverse. A second rod unit is rotatably coupled to the second clamp of the clamping unit at a second coupling site and is also coupled to the traverse via by a rope. A length of a rope section between the second rod unit and the traverse is adjustable by a winch.

Abstract: A wind turbine includes a tower, the tower having an upper part, a middle part and a lower part. The lower and the middle part of the tower form the base of the tower, waste heat generating equipment located in the middle part of the tower, and a cooling device with at least one cooling device inlet formed in the tower for introducing outside air surrounding the tower into the tower. The cooling device is adapted to guide the outside air from each cooling device inlet into the lower part of the tower such that the outside air can ascend towards the middle part and upper part of the tower while cooling the waste heat generating equipment. each cooling device inlet is located in the upper part of the tower.

Abstract: The invention relates to a method for testing a workpiece using ultrasound, wherein an ultrasonic probe generates an ultrasound signal which has a central beam and which is coupled into the workpiece under test, and the central beam is guided along a predefined path on the surface of the workpiece, the central beam and the workpiece being moved in opposite directions at least along a portion of the path.