Abstract: A tool for inspecting a cell formed by grid beams of a top guide structure in a nuclear reactor is provided. The tool includes a camera; a support structure coupled to the camera for contacting at least one of the grid beams to support the camera within the cell; and at least one actuator moving the camera with respect to the support structure and along one of the grid beams, the at least one actuator coupling the camera to the support structure. A method for inspecting a cell formed by grid beams of a top guide structure in a nuclear reactor is also provided.

Abstract: A fuel assembly for a boiling-water reactor has a water channel and a fuel assembly base, made from a sieve plate and a frame section enclosing the same. The water channel supports a plug with a bore running therethrough, at the lower end thereof, to which the fuel assembly base is fixed. The fuel assembly further comprises an opening through the sieve plate, a skirt, formed on the underside of the plug, surrounding the bore, extending into the opening in the sieve plate, a bush, provided with a first and a second longitudinal section, whereby the first longitudinal section extends from the underside of the sieve plate into the opening in a rotationally-fixed manner and a radial shoulder is provided between the two sections which contacts the underside of the sieve plate. A threaded section of a screw extends through the bush which engages in a thread in the bore in the plug.

Abstract: An end piece for a corrugated hose contains a bushing having a front region and a rear region opposite of a longitudinal direction. The rear region is located inside the hose in a mounted state of the bushing. The front region has a collar forming a groove for receiving the free end of the hose. The rear region has a plurality of flexible tongues, which have a relief direction that is oriented perpendicular to the longitudinal direction of the bushing and directed toward the outer chamber of the bushing. A portion of the flexible tongues contains a radially projecting detent protrusion for implementing an engagement active in the longitudinal direction of the bushing. A retaining sleeve, received by the bushing with precise fit and, in the mounted state of the end piece, extends in an inner chamber enclosed by the bushing, limits the radial play of the flexible tongue.

Abstract: A method of decontaminating an oxide layer-comprising surface of a component or a system of a nuclear facility. An acidic water film is produced on the surface, the film of water is brought into contact with a gaseous acid anhydride, and the oxide layer is treated with gaseous ozone as oxidizing agent.

Abstract: Angular sectors of a cylindrical wall of a crucible for vitrification of waste, built in steel and subject to high temperatures, are coated with a mixture of mainly glass and ceramic, the coating being subject to a heat treatment comprising a step between 650° C. and 850° C. so as to perform surface melting of the mixture filling the open porosity, improving dielectric strength and the cohesion of the coating, but without producing any excessive thermal expansion or oxidation of the substrate which would lead to fast flaking of the coating.

Abstract: This invention relates to a circuit breaker (1) for high or medium voltages, of the type having a drive bar (70) coupled to a drive member, and a circuit-breaking chamber (2) facing it and having two contacts (3, 4), each contact (3, 4) including a main contact (30, 40 respectively) and an arcing contact (31, 41 respectively), with one of the two contacts (3) being fixed to a blast or extinguishing nozzle (32). According to the invention, the second contact (4) and the drive bar (70) are joined together by coupling means (6) in such a way that they move together in translation in the same direction, the transmission means (5) being disposed on the side (21) of the chamber (2) that is adjacent to the drive bar (70), and are adapted to transmit the motion of the driven second contact (4) to the first contact (3).

Abstract: A magnetic actuator comprises at least one coil surrounded by a magnetic circuit. The magnetic circuit possesses three legs and two facing end plates. The three legs comprise two outer legs on either side of the coil and an intermediate leg passing through the coil. The legs have no direct mechanical contact with one another. The two facing end plates magnetically interconnect the three legs. The magnetic circuit comprises a moving armature comprising at least one of the end plates, and a stationary portion including a yoke having at least the other one of the end plates and at least one permanent magnet. The permanent magnet is placed at one end of the intermediate leg beside the end plate of the yoke. The magnetic actuator can control medium-voltage and high-voltage circuit breaker vacuum chambers.

Abstract: Method for producing a uranium concentrate in the form of solid particles, by precipitation from a uranium-containing solution using a precipitating agent, in a vertical reactor comprising a base, a top, a central part, an upper part, and a lower part, the solid particles of the uranium concentrate forming a fluidized bed under the action of a rising liquid current which circulates from the base towards the top of the reactor successively passing through the lower part, the central part and the upper part of the reactor, and which is created by introducing a liquid recycling current (flow) at the base of the reactor, said liquid recycling current being tapped at a first determined level (A) in the upper part of the reactor and sent back without settling to the base of the reactor, excess liquid being also evacuated via an overflow located at a second determined level (B) in the upper part of the reactor; a method in which the upper limit (C) of the fluidized bed of solid particles is controlled so that it is

Abstract: A device for checking, measuring and monitoring by ultrasound a hot weld seam between two metal parts, of the type including at least one ultrasonic transmitter. The device includes a shoe equipped with a planar face which is suitable for being in contact with a wall of one of the two parts and includes a housing for maintaining the ultrasonic transmitter in a predetermined orientation in relation to the wall, a cooling system for cooling the ultrasonic transmitter to a temperature below its operating temperature limit, and distributor for depositing and distributing a coupling product between the base plate of the ultrasonic transmitter and the wall.

Abstract: A machine comprising two rollers for ovalising a nuclear fuel cladding to crush the content thereof allowing its easy release even if the pellets are arranged in the cladding with little clearance. The opposite inclinations of the rollers promote automatic forward travel of the claddings. The opening and the inclination of the claddings lead to release of the crushed fuel. The rollers are biconical, with an input portion of increasing diameter and an output portion of decreasing diameter, to apply sufficient ovalisations to crush the fuel whilst restoring rotundity to the cladding when it leaves the machine, to facilitate the outflow of debris.

Abstract: A T-shaped pipe fitting element comprises a main tubular branch having first and second ends for connection to first and second pipe fitting sections of an auxiliary circuit, respectively, and a lateral branch having an axis which is at an angle to the axis of the main branch, and a free end for connecting to a third pipe fitting section of the auxiliary circuit. The first, second, and third pipe fitting sections each have different functions. One supplies the pipe fitting element with a first fluid at a high temperature, another supplies a second fluid to the pipe fitting element, at a lower temperature than the first fluid, and the third discharges a mixture of the first and second fluids. The pipe fitting sections consist of austenitic stainless steel. The T-shaped pipe fitting consists of stainless martensitic steel with improved thermal endurance properties.

Abstract: Embodiments of the present disclosure relate generally to transportation containers and assemblies, such as transportation containers and assemblies for containing and transporting radioactive material. A transportation assembly for transporting radioactive material generally includes an outer container defining an inner cavity, the outer container having an inner shell, wherein at least a portion of the inner shell includes a plurality of layers including at least one layer of chopped fiberglass mat and at least one layer of aramid fabric. The transportation assembly may further include an inner container disposed within the inner cavity of the outer container.

Abstract: A collector system (12) is disclosed that comprises a row of linearly conjoined collector structures (13). The collector system is arranged to be located at a level above a field of reflectors (10) and to receive solar radiation reflected from the reflectors within the field. The collector structure (13) comprises an inverted trough (16) and, located within the trough, a plurality of longitudinally extending absorber tubes (30) that, in use, are arranged to carry a heat exchange fluid. The absorber tubes (30) are supported side-by-side within the trough and each absorber tube has a diameter that is small relative to the aperture of the trough. The ratio of the diameter of each absorber tube to the trough aperture dimension is of the order of 0.01:1.00 to 0.10:1.00 and, thus, the plurality of absorber tubes functions, in the limit, effectively to simulate a flat plate absorber.

Abstract: A method of monitoring voltage stability within an electrical power system comprises the steps of establishing a dynamic power system stability margin based on an operating characteristic of the power system; indicating that the power system has become unstable when the dynamic power system stability margin falls below a predetermined value; and initiating dynamic load shedding and/or restoration depending on stability margin.

Abstract: The present disclosure shows an anti-rotation bolt for fastening reactor plates to prevent subsequent SCC problems wherein the bolt head has a circumferential series of anti-rotation tabs extending from the head of the bolt which are moved in by a restrainer cone which is placed on top of the bolt to allow its insertion into the plates and is removed for locking the tabs into detents formed in one of the plates to provide anti-rotation. The cone is again moved over the tabs during the removal of same leaving the bolt undamaged and fit for reuse.

Abstract: A handling system including a tool for lifting the container, wherein the lifting tool includes a lifting carrier to be suspended and a member for gripping the container comprising removable devices for fastening the container onto the gripping member. According to one aspect of the invention, the gripping member is mounted so that it may rotate on the lifting carrier about a substantially horizontal rotation axis when the lifting carrier is suspended.

Abstract: An electrical insulator including a tube surrounded by an insulating sheath. The insulating sheath is composed of a filled, hardened, flexibilized, hydrophobic, cycloaliphatic epoxy resin containing from 25 to 75 percent by weight of mineral filler. The process for manufacturing this insulator includes the steps of installing the insulator tube or a precursor of the tube in an electrical insulator mold, feeding the filled unhardened hydrophobic cycloaliphatic epoxy resin in the mold so as to form the sheath, hardening the resin inserted in the mold so as to obtain the insulator, and extracting the insulator obtained from the mold.

Abstract: The gas-tight, high or medium voltage electric switch device (1), containing an insulating gas under pressure, comprises switch contacts (2) capable of occupying an open position and a closed position and disposed inside a composite insulator formed by a rigid tube (3) surrounded by an elastomer casing (4) whose outside surface defines a succession of annular fins. The rigid tube and the elastomer casing are arranged so as to define an observation window (7) that is at least translucent, and through which the open or closed position of the switch contacts is visible.

Abstract: A method of evaluating at least one quantity relating to the distortion of a nuclear fuel assembly, the method including the following steps: the nuclear fuel assembly is placed in a volume of water bounded by an upper free surface; a camera is placed outside the volume of water, above the free surface; at least one image of at least one lateral face of the nuclear fuel assembly is taken; the at least one image is analyzed graphically and the at least one quantity relating to the distortion of the nuclear fuel assembly is deduced therefrom.

Abstract: A sintered fuel pellet for a water nuclear reactor fuel rod including a peripheral wall extending along a central axis and two end faces. At least one of the end faces includes at least a first chamfer extending from the peripheral wall towards the central axis with a first non-zero slope with respect to a plane perpendicular to the central axis and a second chamfer extending from the first chamfer towards the central axis with a second non-zero slope with respect to a plane perpendicular to the central axis, wherein the first slope is different from the second slope.