Abstract: A clamp for a boiling water reactor feedwater sparger is disclosed and claimed. The clamp assembly includes abuse and cooperating bolt, a reaction arm, and a cross pin. With the exception of the cross pin, the parts are pre-assembled and then installed over the sparger pin head. The cross pin is then installed through the clamp base and through the sparger pin. The clamp bolt is then tightened, locking the clamp and sparger pin. The clamp provides an increased surface area that extends 360° around the sparger pin. This increased surface area reduces the likelihood of wear of the clamp or bracket during plant operation, and the clamp restores the position of the sparger pin head relative to the contact surface of the end bracket if the original pin head or bracket is worn.

Abstract: A nuclear facility comprising an anchor device is provided. This anchor device comprises a female part and a male part. The female part includes a groove extending along a longitudinal axis. The groove has a width which decreases longitudinally and a transverse section. The male part includes a slider with a shape mating that of the groove and is able to be longitudinally inserted into the groove. The transverse section of the groove is configured so as to prevent the extraction of the slider out of the groove transversely to the longitudinal axis. The anchor device includes a locking device able to prevent the slider from longitudinally sliding out of the groove.

Abstract: A method of decontaminating metal surfaces in a cooling system of a nuclear reactor comprises conducting a plurality of treatment cycles, with each of the treatment cycles comprising: an oxidation step wherein metal oxides including radioisotopes on the metal surfaces are contacted with an aqueous solution of a permanganate oxidant; a decontamination step after the oxidation step wherein the metal oxides are contacted with an aqueous solution of an organic acid selected from the group consisting of oxalic acid, formic acid, citric acid, tartaric acid, picolinic acid, gluconic acid, glyoxylic acid and mixtures thereof so as to dissolve at least part of the metal oxides and the radioisotopes; and a cleaning step wherein at least the radioisotopes are immobilized on an ion exchange resin; wherein the oxidation step comprises at least one acidic oxidation step and at least one alkaline oxidation step carried out one after another in either the same or different treatment cycles; and wherein the plurality of treat

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: A passive two-phase cooling circuit includes a vaporizer and a condenser for a coolant conducted in the cooling circuit. A vaporizer supply line and a vaporizer discharge line are connected to the vaporizer, and a condenser supply line and a condenser discharge line are connected to the condenser. The cooling circuit has a simple and cost-effective structure which reduces or even completely prevents pressure shocks during operation by connecting the vaporizer supply line, the vaporizer discharge line, the condenser supply line and the condenser discharge line to a common damping container. A liquid column forms in the condenser discharge line during the operation of the cooling circuit and the column assumes the function of a liquid-tight seal and of a fluid-dynamic vibration damper.

Abstract: The invention provides a method of preparing irradiation targets for radioisotope production in instrumentation tubes of a nuclear power reactor, the method comprising the steps of: providing a powder of an oxide of a rare earth metal having a purity of greater than 99%; consolidating the powder in a mold to form a round green body having a green density of at least 50 percent of the theoretical density; and sintering the spherical green body in solid phase at a temperature of at least 70 percent of a solidus temperature of the rare earth metal oxide powder and for a time sufficient to form a round sintered rare earth metal oxide target having a sintered density of at least 80 percent of the theoretical density.

Abstract: A method of decommissioning a nuclear reactor including a vessel defining an inner chamber and reactor internal components positioned within the inner chamber includes removing at least some of the internal components and repackaging at least some of the removed internal components in at least one of the first and second predefined sections of the vessel defining a cutting zone between the at least first and second predefined sections. The method further includes disposing the vessel in a container, and encapsulating the internal components in the vessel and encapsulating the vessel in the container to generate a package. A package including components from a decommissioned and dismantled nuclear reactor includes a vessel and a plurality of components encapsulated in the vessel.

Abstract: The present invention relates to a process for sintering a compacted powder of at least one oxide of a metal selected from an actinide and a lanthanide, this process comprising the following successive steps, carried out in a furnace and under an atmosphere comprising an inert gas, dihydrogen and water: (a) a temperature increase from an initial temperature TI up to a hold temperature TP, (b) maintaining the temperature at the hold temperature TP, and (c) a temperature decrease from the hold temperature TP down to a final temperature TF, in which the P(H2)/P(H2O) ratio is such that: 500<P(H2)/P(H2O)?50 000, during step (a), from TI until a first intermediate temperature Ti1 between 1000° C. and TP is reached, and P(H2)/P(H2O)?500, at least during step (c), from a second intermediate temperature Ti2 between TP and 1000° C., until TF is reached.

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 method for controlling the gain and zero of a multiple pixel photon counter device, and light-measuring system implementing said method. Signals provided by the device are acquired for predefined periods, until a predefined total measurement time is reached, an amplitude histogram is formed from the acquired signals, the positions of two consecutive peaks, measurable on the histogram, are determined, an error signal is produced, which is equal to the deviation between both peaks and, by means of the same, the voltage supplying the device is regulated, so as to keep the deviation equal to a predefined set point.

Abstract: A nuclear fuel assembly spacer grid defining a lattice of cells for receiving fuel rods is provided. The spacer grid includes a peripheral band composed of at least one peripheral strip delimiting a portion of the peripheral contour of the spacer grid, and at least one spacer grid positioning spring elastically deformable and formed in the peripheral band.

Abstract: An enhancing device for piercing plugs in a steam generator is provided. The enhancing device includes a main body, and a bit, borne by the main body and extending along a longitudinal axis. The bit may be driven into rotation around its longitudinal axis, in order to perform an action for piercing a plug. The device includes a hollow tubular element, extending along the longitudinal axis, while surrounding the bit and coaxially with this bit, the tubular element including an outer surface having a screwing thread, intended to be screwed onto the plug prior to the piercing. The tubular element may be driven into rotation around the longitudinal axis, independently of the rotation of the bit.

Abstract: A lower nozzle for use in a nuclear fuel assembly provided. The lower nozzle is of the type having an axis and comprising a transverse lower tie plate for channeling the coolant through the lower tie plate and a tubular skirt extending axially from the periphery of the lower tie plate, the skirt delimiting an axial housing closed at one end by the lower tie plate and open at the opposite end, a debris filter configured for axial insertion in the housing and snap-fit springs for retaining the debris filter in the housing after insertion. The springs are configured to shift the debris filter axially towards the lower tie plate.

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: A method for measuring the deflection of a fuel element can for a fuel element of a boiling water reactor involves taking an image of the fuel element can with a camera and evaluating the image using photogrammetry. By means of the method, it is possible to determine the deflection of a fuel element can by taking a single image, even in the absence of external structural features recognizable in the image, and without knowledge of the relative position between the camera and the fuel element can.

Abstract: A lifting beam is provided. The lifting beam includes a lower beam and an upper beam arranged above the lower beam; an arranger for arranging the beams in close and releasable engagement with one another; and systems for gripping the load. The gripping systems are kept in an open position when the beams are in engagement with one another, and in a closed position when an engager is released.

Abstract: The invention relates to an assembly and a method of fixing a rotor blade of a wind power plant. The wind power plant comprises a rotor blade, a pitch adjustment means, a bearing for the rotor blade and a brake disk. There is an electro-mechanical brake configured to apply a controlled brake force to the brake disk that is a function of the pitch angle of the rotor blade.

Abstract: The invention relates to a heating rod for a pressurizer of a primary cooling system of a pressurized-water nuclear reactor, the rod comprising a metal outer shell (36) of longitudinally elongate shape having an external surface (62), and a heating element (40) mounted inside the shell (36). It comprises an anti-corrosion coating (60) covering at least part of the external surface (62) of the shell (36).

Abstract: A method of decommissioning a nuclear reactor including a vessel defining an inner chamber and reactor internal components positioned within the inner chamber includes removing at least some of the internal components and repackaging at least some of the removed internal components in at least one of the first and second predefined sections of the vessel defining a cutting zone between the at least first and second predefined sections. The method further includes disposing the vessel in a container, and encapsulating the internal components in the vessel and encapsulating the vessel in the container to generate a package. A package including components from a decommissioned and dismantled nuclear reactor includes a vessel and a plurality of components encapsulated in the vessel.

Abstract: A method of operating a nuclear reactor is provided. The method includes defining a layer increment of a deposit layer modeling a deposit on a heat transfer surface of the nuclear reactor; periodically updating a thickness of the deposit layer by adding the layer increment to the deposit layer; recalculating properties of the deposit layer after each layer increment is added to the deposit layer; determining a temperature related variable of the heat transfer surface as a function of the recalculated properties of the deposit layer; and altering operation of the nuclear reactor when the temperature related variable of the heat transfer surface reaches a predetermined value. A method of modeling a deposit on a heat transfer surface of a nuclear reactor is also provided.