Abstract: A fuel assembly for a light water reactor contains a fuel rod cluster and a spacer that has a number of cells, bounded by webs for laterally holding fuel rods. A damaged region including at least one damaged cell is present in an edge region of a spacer. There being fastened above or below the damaged region on the spacer with the aid of at least one connecting part is a replacement assembly that contains at least a number of cells that corresponds to the number of the damaged cells, at least a portion of the cells being traversed by fuel rods. A method for repairing the light water reactor fuel assembly in the case of which fixed above or below the damaged region on the spacer is a replacement assembly that takes over the holding function at least of one defective cell.

Abstract: A method produces a welded connection between first and second components each having inner and outer sides interconnected by an end face. The first component has a ferritic basic body carrying a plating at the inside and having an end face with a buffer layer of Ni-based alloy. The second component is of austenitic material. The end faces of the components enclose a weld groove. An austenitic root, connecting the plating to the end face of the second component, is welded in the weld groove. An intermediate layer of a nickel alloy having at least 90% nickel is welded onto the root. The intermediate layer is connected to the end faces of the plating and the second component. A weld seam is then produced in the remaining weld groove using a nickel-based welding additive. A method for repairing a welded connection between first and second components is also provided.

Abstract: A connecting sleeve generally used for a bus bar connection is produced from an insulating elastic material, often an elastomer material, having insulating properties which are deteriorated by partial discharges and decrease over the operating time of the switchboard system. According to the invention, so-called partial discharge measuring methods must be carried out, inter alia also in the UHF range (UHF: ultra high frequency), in order to identify damaging effects on the insulating material in time. For the reliable and simple detection of the measuring signals, the connecting sleeve (M) has an outer, electroconductive surface (OA) which is earthed, and an inner, electroconductive surface (OI) to which the voltage potential of the bus bar (S) is applied, in addition to a coupling electrode (KE) which is integrated into the insulating material (I).

Abstract: A method for determining the reclose time of a circuit breaker on a three-phase high-voltage electric network after separation of contacts 7A, 8A, 7B, 8B, 7C, 8C in the presence of a fault on one of the three phases A, B or C includes measuring voltages ULA0, ULBO and ULCO, measuring voltage USAO,determining the voltage USA0, USB0, and USCO, calculating the differences ULAB, ULAC and ULBC, calculating the differences USAB, USAC, and USBC. From these measurements and calculations, a determination of the reclose time is made on the basis of the voltage differences.

Abstract: An alternator disconnector circuit-breaker of the invention includes a cylindrical cam (40) for optimizing the sequence for opening/closing the switch-over first switch (10), the circuit-breaker second switch (20), and the disconnector third switch (30). The cam (40) has a cylindrical wall in which three slots (42), and preferably three pairs of slots, of different shapes, are defined; an end element of an element driving a respective one of the switch contacts is mounted to slide in each slot.

Abstract: A highly temperature-stable capacitor for taking measurements on a high-voltage line, said capacitor having a high-voltage electrode (HT), an annular printed circuit (CI) surrounding said high-voltage electrode (HT) coaxially and having at least one electrically conductive track that forms a low-voltage electrode (BT), said capacitor being characterized in that the printed circuit (CI) also has at least one temperature-sensitive resistor (TH).

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: Pressuriser for a pressurised water nuclear power station, comprising an outer casing which delimits an inner space; a duct (11) which extends beneath the casing and which is capable of being tapped from the coolant system of the nuclear power station; a tap (18) which places the inner space of the casing in communication with the duct (11), this tap (18) being welded to the duct (11) by means of a weld seam (32); a sleeve (42) for protecting the weld seam (32), which sleeve is arranged inside the tap (18) and which has a lower peripheral edge (46) which is engaged in the duct (11), the sleeve (42) defining with the tap (18) and the duct (11) an annular space (74) which is capable of being filled with the primary liquid; wherein the annular space (74) is open along at least a portion of the lower peripheral edge (46) of the sleeve (42) and opens inside the duct (11).

Abstract: The method is implemented with a management system of the time-triggered architecture type in association with a processor of a central processor unit that possesses a privileged execution mode to which access is protected by an instruction of the “call to system layer” type. The only system layer call that is authorized from an application task under consideration to the system layer consists in reporting a change of node in the control graph of the task in question. When the system layer has verified that the call is legal relative to the execution paths of the control graph as described in the constant tables of the application, all of the operations to be performed on the node in question by the system layer are predetermined by the constant tables of the application associated with the system layer.

Abstract: A first switch (10) has a first pair of contacts (12, 14) that are mounted to move relative to each other in translation. A circuit-breaker second switch (20) has a second pair of contacts (21, 24) that are mounted to move relative to each other in translation, the second switch (20) being put in parallel with the first switch (10). A disconnector third switch (30) has a third pair of contacts (32, 34) that are mounted to move relative to each other. Synchronization means (50, 50?) make it possible, while breaking is taking place, for the contacts of the first switch (10) to separate before the contacts of the second switch (20) separate, the contacts of the second switch themselves separating before the third contacts (32, 34) separate fully. The synchronization means are actuated by a servomotor (40).

Abstract: A method for protecting the components of the primary system of a boiling water reactor, especially against stress cracking corrosion, includes feeding a reducing agent into the primary coolant in order to reduce the number of substances having a oxidizing effect or in order to modify the electrochemical potential of the component surfaces covered with an oxide layer to negative values. An alcohol that can be oxidized in the conditions of a reactor is fed in as a reducing agent, preferably in a liquid form, into the primary coolant. The component surfaces are provided with a blank coating or a single intrinsic oxide coating.

Abstract: This invention relates to a method for detection of a position of a wave front in a signal received by a detector. This method includes converting the signal into a digital signal, defining a working group of N successive samples in the digital signal, and processing at least some of the samples in the working group. Energy of the signal is calculated from the processed samples in the working group in terms of the root mean square over a sliding window, the window including an optimum number Lopt of samples (Lopt is less than N). Also included is detecting the position of the wave front corresponding to the position of the sample for which the energy of the signal exceeds a threshold D that depends on the value of the energy of the signal previously at the wave front, for the first time.

Abstract: A semiconductor device capsule comprising a semiconductor assembly mounted between opposed poles. At least one of the poles includes slots around the locality of the or each chip or group of chips within the semiconductor assembly to define a contact body portion on which the or each chip or group of chips is mounted and reduce the thickness of a laterally continuous body portion of the pole.

Abstract: A method of supervising the operation of a plurality of current transformers arranged in respective groups and connected to a protection relay forming part of a three-phase electrical power system includes determining a current ratio at an output of each group of current transformers, comparing each current ratio with a predetermined high ratio, comparing each current ratio with a predetermined low ratio, and generating a fault indication when the current ratio at one location exceeds the predetermined high ratio and the current ratio at the or each other location remains below the predetermined low ratio.

Abstract: The invention relates to a high-performance dielectric oil comprising approximately 75 to 95% by volume of a naphthenic oil and approximately 5 to 25% by volume of an ester oil, in particular a synthetic ester oil and more preferably an oil of the family of polyolesters. Applications: high-voltage electrical equipment, for example power, measurement, distribution or traction transformers, tap changers, bushings, distributors, oil-immersed circuit breakers, power capacitors, cables, etc.

Abstract: An assembly for monitoring and locating leaks in an installation includes a collecting line formed of a material that is impermeable to a substance to be monitored. The collecting line has a multiplicity of openings spaced apart in its longitudinal direction. The openings are closed with a filter element of a sintered metallic material that is permeable to the substance and has been subjected to a heat treatment in an oxidizing atmosphere.

Abstract: The invention relates to a process for repairing at least one connecting area between a partition plate (8) and a tube plate (5) of a water chamber (7) of a heat exchanger (1), in which process the area of weld requiring repair is identified, at least one rail (11) is inserted into the water chamber, the said rail (11) is attached below the tube plate (5), a robot arm (20) is inserted, the robot arm is hoisted within the water chamber, the robot arm is remotely controlled, the connecting area requiring repair is machined and a check is made to ensure that cracks have been eliminated from the repaired area.

Abstract: The invention relates to a pressurised water nuclear reactor vessel, comprising: an outer casing which comprises at least one cylindrical shell and a dished bottom head, a core support plate, a vessel bottom head space being delimited between the support plate and the dished bottom head, the support plate being perforated with holes for circulation of the primary coolant which place the vessel bottom head space in communication with the core, a calming device which is arranged in the vessel bottom head space, wherein the calming device comprises at least one calming plate which is substantially perpendicular relative to the centre axis of the vessel and a plurality of calming holes, the calming holes being provided in the calming plate and being capable of calming the primary coolant by passing the fluid through the holes.

Abstract: The invention relates to a magnetic actuator comprising at least one coil (14) surrounded by a magnetic circuit (10), the magnetic circuit possessing: three legs (12.1, 12.2, 11), comprising two outer legs on either side of the coil (14) and an intermediate leg passing through the coil, these legs having no direct mechanical contact with one another; and two facing end plates (17, 18) magnetically interconnecting the three legs (12.1, 12.2, 11). The magnetic circuit comprises a moving armature (21) comprising at least one of the end plates (18), and a stationary portion (200) including a yoke (22) having at least the other one of the end plates (17) and at least one permanent magnet (13), the permanent magnet (13) being placed at one end of the intermediate leg (11) beside the end plate (17) of the yoke (22). The invention is applicable to controlling medium-voltage and high-voltage circuit breaker vacuum chambers.

Abstract: The invention relates to a device for controlling a circuit-breaker intended for opening and closing this electric power cut-off device comprising a mobile contact, this control device comprising a motor (3) with a rotary output shaft (12) and being connected to power supply means (4-9) and actuating means transforming the output displacement of the motor into a displacement of the contact, this device also comprising a mechanical spring arrangement involved in opening and closing the contact. According to the invention, the actuation means include a set of jointed elements providing the connection of the rotary shaft and of the ring, and, in the closed position of the contact, the set of jointed elements is near a dead centre position, a so-called open dead centre, the opening spring (15) being only able to drive it towards the open position upon moving past this dead centre during opening.