Abstract: A control rod for a pressurized-water nuclear reactor contains an absorber rod which is arranged in a casing tube. At least in a lower section, the absorber rod is provided with at least one recess which takes up at most a portion of the circumferential surface of this section. This reduces problems associated with an expansion in the volume of the absorber rod.

Abstract: The present invention relates to a method for detecting the drop of a cluster in a pressurized-water nuclear reactor, comprising the steps of: detecting a negative time derivative of the neutron flux, and comparing the absolute value of said time derivative to a first threshold value (S1); triggering a time delay (?T) if said absolute value is greater than said threshold value (S1); detecting a positive time derivative of said neutron flux, and comparing the absolute value of said time-derivative to a second threshold value (S2); and triggering the emergency shutdown of the reactor if the absolute value of said positive time derivative of said flux becomes greater than said second threshold value (S2) during said time delay (?T).

Abstract: A copper-based winding implementing a copper-based winding of diameter that is typically greater than 90 mm, designed to generate a magnetic field in an electrical contact for a medium-voltage vacuum circuit-breaker. The winding is constituted by a hollow cylinder including helical slots about its longitudinal axis and opening out both into the hollow and to the exterior of the cylinder, winding in which the space between two consecutive slots that form a turn is empty of material and the width of each initial slot is less than 1 mm.

Abstract: The invention provides at least two electrochemical sensors positioned in a nuclear reactor or in a system adjacent to the nuclear reactor, wherein at least one of the at least two electrochemical sensors has a heated zirconium electrode, and the at least two electrochemical sensors produce voltages proportional to an electrochemical corrosion potential for a surface that each of the at least two electrochemical sensors are installed upon. The invention also provides an arrangement configured to accept the voltages produced by the at least two electrochemical sensors, wherein the arrangement is configured to determine an electrochemical corrosion potential of a zirconium fuel rod in the nuclear reactor based upon the voltages of the at least two electrochemical sensors.

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 tubular pipe (10) for transporting liquid sodium is suitable for inhibiting any leaks of sodium outside the pipe. The pipe includes a pipe body (20) covered on the inside with an inner layer which includes: a first continuous layer (40) made of ceramic or a metal or metal alloy, for being placed in contact with the liquid sodium carried by the tubular pipe; and between the pipe body and the first ceramic layer, an intermediate layer (50) made of a reactive material which, when the layer contacts the liquid sodium, the layer turns into a modified material which has separate electric conductivity from that of the reactive material.

Abstract: A mirror is shaped using a shaping apparatus including a crossbar and a horizontal array of members (wheels in some embodiments) attached to a bottom of the crossbar. The height of the array of members is adjusted to form a predetermined shape. The shaping apparatus is positioned over a mirror such that the members contact the mirror. The shaping apparatus is moved along a length of the mirror such that the members remain in contact with the mirror. A frame is attached to the mirror such that when the shaping apparatus is removed from the mirror, the mirror substantially retains the predetermined shape.

Abstract: A nuclear fuel assembly for a boiling water reactor is provided. The nuclear fuel assembly includes a base, a head and a bundle of full length fuel rods and partial length fuel rods. The bundle extends longitudinally between the base and the head, at least one partial length fuel rod having a lower end received in a housing provided in the base and delimited by a closed bottom larger than the lower end. The housing is further delimited by a peripheral wall surrounding the lower end and the partial length fuel rod rests freely on the bottom.

Abstract: A method for machining a sealing seat of a shut-off valve in a power generating or industrial plant. An upper valve part and the internal housing fittings are removed from the housing of the shut-off valve to thereby expose a housing opening. A clamping device with a counter-bearing is introduced through the housing opening into the connection pipe and fastened to its inner wall. A machine tool with a bearing is introduced through the housing opening and mounted with its bearing on the counter-bearing. A machining step is carried out with the machine tool on the sealing seat. Then the machine tool is detached and removed through the housing opening. The clamping device is detached from the connection pipe and removed through the housing opening. Then, the upper valve part and the internal fittings are reattached to the housing.

Abstract: A monitoring system for an inner area of a machine includes a radar source radiating or injecting radar radiation into the inner area and a radar receiver receiving radar radiation reflected in the inner area and emitting the reflected radar radiation as a received signal. A control and evaluation unit determines an actual signature from the received signal and compares the actual signature to a stored nominal signature representing a fault-free machine. An output unit outputs a fault error signal when a discrepancy between the actual signature and the nominal signature exceeds a tolerance value.

Abstract: Systems, methods, and apparatus by which solar energy may be collected as heat are disclosed. Some systems include an elevated solar receiver comprising multiple tubes arranged lengthwise in the receiver in a side-by-side parallel configuration across a transverse dimension of the receiver. The receiver comprises an inlet section configured to receive a heat transfer fluid into the tubing arrangement and an outlet section configured to output heated heat transfer fluid from the tubing arrangement. The multiple tubes of the tubing arrangement define together a flowing circuit between the inlet section and the outlet section from the outer tube or tubes to the inner tube or tubes. The solar energy collector system further includes an instrumentation and control system for controlling the orientation of at least one orientable reflector to provide in operation a concentrated illuminated area comprising a peaked profile across the transverse dimension of the receiver.

Abstract: A method for the fluid-tight assembly of two parts silicon nitride respectively comprising a male end and a female end, each of these ends being provided with mechanical assembly means capable of cooperating together and which, under assembling conditions, delimit a space -between them, said method comprises the assembling of the said parts by cooperation of the mechanical assembly means of the male and female ends, and filling of the space existing between these assembly means with a glass joint, and is characterized in that this filling comprises: coating, before assembling of the parts, the mechanical means of one and/or the other of the male and female ends with a borosilicate glass paste; and applying heat treatment to the parts after the assembling thereof.

Abstract: A cyclone separator for phase separation of a fluid stream has a rotationally symmetrical housing with a hollow chamber. Feed lines feed the fluid stream into the housing substantially tangentially. At least one discharge line conducts the separated gaseous fraction. In order to ensure uniform and homogeneous flow distribution of the steam to be heated as it enters the heating phase, the hollow chamber, when viewed in the radial direction from the mid-axis, has an outflow chamber with a circular cross section and, in radial sequence, a heating chamber, an intermediate chamber, a dryer chamber and an inflow chamber. The inflow chamber is outwardly delimited by the housing. The heating chamber contains heating elements for heating the gaseous fraction. At least one fine separator and at least one associated condensate-collecting trough are arranged in the dryer chamber.

Abstract: The invention relates to a tool used for pressure crimping and driving-out of a cleat, comprising: (a) a first receptacle opposite which is located a crimping head movably mounted on a body of the tool; (b) a second receptacle opposite which is located a drive-out head also movably mounted on the body; and (c) pressure means movably mounted on the body so as to be able to be displaced from a crimping position in which they are capable of exerting pressure on the crimping head, to a drive-out position in which they are capable of exerting pressure on the drive-out head, and conversely.

Abstract: An alternator disconnector circuit-breaker of the invention presents a resistance (30) in series with the circuit-breaker switch (20?); the resistance (30) is of fixed ohmic value that is about 104 times greater than the value of the resistance of the main circuit of the circuit-breaker. By means of this configuration, it is possible to use a vacuum chamber as the circuit-breaker switch (20?), and to dimension the main switch (10), which, de facto, breaks the current even for very high short-circuit currents, under more advantageous conditions.

Abstract: A method and a device measure for a deformation of a fuel element of a pressurized water reactor having a plurality of control rod guide tubes. A probe displaceable in the direction of the longitudinal axis of the control rod guide tube is inserted in the interior of at least one control rod guide tube having at least one reference axis, and supported in at least one section of the control rod guide tube on the interior wall thereof, such that the orientation of the at least one reference axis is unambiguously a function of the orientation of the longitudinal axis of the control rod guide tube in the section. The orientation of the at least one reference axis in the section of the control rod guide tube is determined relative to the orientation of the or a further reference axis of the probe in a different section.

Abstract: A container including a support having at least one first longitudinal support surface defining a longitudinal housing for receiving a nuclear fuel assembly, and a door having a second longitudinal support surface. The door is movable between a position of holding the nuclear fuel assembly between the two longitudinal surfaces and a released position in which the assembly is free with respect to the support. The container includes means for adjusting the transversal separation between the first and second surfaces in the holding position of the door.

Abstract: A method for regenerating a solid filter containing iodine in the form of silver iodide and/or iodate and possibly molecular iodine physisorbed, in a solid filter containing silver in the form of nitrate. The iodine is extracted from the filter by putting the filter into contact with a basic aqueous solution containing a reducing agent. The extraction is achieved at room temperature, and then the filter is separated from this basic aqueous solution. Next, silver is extracted from the filter by putting the filter into contact with an acid aqueous solution. The filter is then separated from the acid aqueous solution. Finally, the filter is impregnated with silver by putting the filter into contact with a silver nitrate solution and then drying the filter. This method can be used in nuclear installations, notably factories for reprocessing used nuclear fuels.

Abstract: A method for retrofitting a boiling water reactor is provided. The method includes removing a mixing chamber from a slip joint defined by a diffuser and the mixing chamber, the mixing chamber having an inner surface and a bottom edge directing flow to the diffuser such that a recirculation zone at an entrance to the slip joint creates a diverging effective path for the leakage flow entering the slip joint. The method also includes providing a new inner surface and new bottom edge, the new inner surface and the new bottom edge being reshaped to decrease the size of the recirculation zone. A jet pump is also provided.

Abstract: A fault current limiter, with a superconducting device (1; 21; 31; 41; 51; 61; 71; 72) comprising a sequence of superconducting elements (2a-2f), each with an electrically conducting substrate (3a-3d), a superconducting film (5a-5d), and an electrically insulating intermediate layer (4a-4c) provided between the substrate and the superconducting film, wherein the superconducting films (5a-5d) of adjacent superconducting elements (2a-2f) of the sequence are electrically connected, in particular in series, wherein the electrically conducting substrate (3a-3d) of each superconducting element (2a-2f) of the sequence is electrically insulated from each electrically conducting substrate (3a-3d) of those adjacent superconducting elements (2a-2f) within the sequence whose superconducting films (5a-5d) are electrically connected in series with the superconducting film (5a-5d) of said superconducting element (2a-2f).