Abstract: A method chemically decontaminates a surface of a metal component of a primary circuit of a pressurized-water reactor, the surface contains an oxide layer. In a first stage, an oxidation step, a reduction step, and a first decontamination step are performed. The component is treated in the oxidation step with an aqueous solution containing an oxidizing agent, which converts trivalent chrome present in the oxide layer into hexavalent chrome. The component is treated in the reduction step with an aqueous solution containing a reducing agent for reducing excess oxidation agent from the oxidation step. The component is treated in the first decontamination step with an aqueous solution containing a decontamination acid that forms no antisoluble deposits with metal ions in the solution. The solution is fed through an ion exchanger for removing metal ions. In a second stage, the component is treated with an aqueous solution containing an oxalic acid.

Abstract: A nuclear power plant is provided including a BWR, a reactor cooling system cooling the BWR, an HWC hydrogen injection system connected to the reactor cooling system and an alcohol injection system connected to the reactor cooling system. Methods for providing methanol and hydrogen are also provided.

Abstract: A method for treating or preparing a fuel rod cladding tube in such a way that an influence of iron oxide deposits on its surface can be studied and assessed precisely under virtually operational conditions with as little risk as possible, includes at least partially coating the fuel rod cladding tube with an iron oxide layer by immersing it in an aqueous electrolyte medium which contains iron oxide particles. The iron oxide particles are produced by anodic oxidation of an iron-containing working electrode. A test body and a device for pretreating a fuel rod cladding tube with an electrochemical three-electrode configuration, are also provided.

Abstract: A control device, including a transmission shaft adapted to be coupled to an apparatus to be controlled, a driving disk mounted on said transmission shaft to rotate thereon and driven in rotation by a motor unit, a driven disk constrained to rotate with said transmission shaft, and a rotary member carrying at least one indexing means which, due to rotation of said rotary member, can be simultaneously engaged into two respective slots of said two disks for said transmission shaft to be driven in rotation, and can be disengaged from one of said slots for said transmission shaft to be locked against rotation.

Abstract: A nickel, chromium, iron alloy and method for use in producing weld deposits and weldments formed therefrom. The alloy comprises, in weight percent, about 28.5 to 31.0% chromium; about 0 to 16% iron; less than about 1.0% manganese; about 2.1 to 4.0% niobium plus tantalum; 1.0 to 6.5% molybdenum; less than 0.50% silicon; 0.01 to 0.35% titanium; 0 to 0.25% aluminum; less than 1.0% copper; less than 1.0% tungsten; less than 0.5% cobalt; less than about 0.10% zirconium; less than about 0.01% sulfur; less than 0.01% boron; less than 0.03% carbon; less than about 0.02% phosphorous; 0.002 to 0.015% magnesium plus calcium; and balance nickel and incidental impurities. The method includes the steps of forming a welding electrode from the above alloy composition and melting the electrode to form a weld deposit. A preferred weldment may be in the form of a tubesheet of a nuclear reactor.

Abstract: A method for treating spent nuclear fuel, which includes first decontaminating the uranium, plutonium and neptunium found in a nitric aqueous phase resulting from dissolving the nuclear fuel in HNO3. The uranium, plutonium and neptunium found in the solvent phase is then split in a first aqueous phase and a second aqueous phase. Next, the first aqueous phase is stored. Following, the plutonium or other mixtures found in the first aqueous phase is purified relative to the fission products still found in said phase, in order to obtain, at the end of said purification, an aqueous solution containing a mixture of Pu and U or Pu, U and Np. Finally the resulting mixture of Pu and U or the mixture of Pu, U and Np is co-converted into a mixed oxide.

Abstract: A temperature measurement tube is composite and comprises a rigid shaft (1), which is cooled so as to shield it from corrosion and from the melt, and an end-fitting (15) housing a thermocouple (9) on the end of the tube and constructed from a noble metal, which is resistant to corrosion and to the high melting point. An alumina coating (13) is placed between the two metals in order to prevent any corrosion-inducing electrochemical exchange between them.

Abstract: A system for producing at least one hydrocarbon fuel from a carbonaceous material, the system including: a nuclear power plant; a hydrocarbon fuel manufacturing plant, including at least an electrolyzer unit for producing a first hydrogen stream from water and electric power provided by the nuclear power plant, and an hydrocarbon fuel synthesis unit, the nuclear power plant supplying power to a power distribution grid to which electric power consumers other than the hydrocarbon manufacturing plant are electrically connected; a buffer storage of at least one given hydrocarbon fuel; a reforming unit for producing a second hydrogen stream from the at least one given hydrocarbon fuel, and a device to feed the at least one given hydrocarbon fuel to the reforming unit at a controlled feed flow rate; a device to feed the hydrocarbon fuel synthesis unit with the first hydrogen stream at a first controlled flow rate and with the second hydrogen stream at a second controlled flow rate; and a device to control the fi

Abstract: A chemical element to be very efficiently separated from uranium starting from an acid aqueous phase, in an extraction cycle for the uranium, when this chemical element is present in said phase at a concentration less than that of the uranium, or even as a trace element, and when it is moreover less extractable by the extractant used in this extraction cycle than is the uranium. The chemical element can notably be neptunium(IV) or thorium 228.

Abstract: An assembly for producing at least one synthetic hydrocarbon from at least one inflowing stream of carbon monoxide and one inflowing stream of carbon dioxide is provided. The assembly includes an electrolyzer provided for producing a first stream of hydrogen, a first conversion unit provided for producing an intermediate stream of carbon monoxide from at least one portion of the inflowing stream of carbon dioxide and hydrogen, a reactor for synthesizing said synthetic hydrocarbon; a second conversion unit provided for producing a second stream of hydrogen from carbon monoxide and water, the second hydrogen stream being directed towards the synthesis reactor; a guide assembly provided for selectively distributing the inflowing stream of carbon monoxide between the second conversion unit and the synthesis reactor, and for selectively distributing the first hydrogen stream between the first conversion unit and the synthesis reactor; a control unit provided for controlling the guide assembly.

Abstract: A nuclear engineering plant has a containment, whose interior chamber is subdivided by a wall into a systems chamber and an operating chamber which is accessible during normal operation. The containment ensures a particularly high operational reliability, in particular also in incident situations, in which hydrogen is released in the systems chamber. For this purpose, a number of overflow openings are provided in the partition wall, the respective overflow opening is closed by a closure element of a closure apparatus which opens automatically when a trigger condition associated with the respective overflow opening is reached. Closure apparatuses are provided which open both as a function of pressure and independently of pressure. The closure apparatus furthermore has a closure element containing a bursting film or a bursting diaphragm. The closure apparatus is configured such that it frees the overflow opening automatically when a predetermined environment-side trigger temperature is reached.

Abstract: Process for decontaminating, cleaning a solid organic substrate contaminated by solid radioactive particulate inorganic contaminants, in which: the said solid substrate is brought into contact with an extraction medium, devoid of water, comprising: dense pressurized CO2; at least one nonhalogenated surface-active compound chosen from block copolymers of poly(ethylene oxide) PEO and poly(propylene oxide) PPO, such as (EO)x-(PO)y diblock copolymers, (EO)x-(PO)y-(EO)x triblock copolymers and (PO)x-(EO)y-(PO)x, triblock copolymers, where x and y are integers from 2 to 80 with x other than y; and polydi(1 to 6C)alkylsiloxanes, such as polydimethylsiloxane (PDMS); and at least one complexing agent chosen from tributyl phosphate (TBP), crown ethers, tributylphosphine oxide, triphenylphosphine oxide and tri(n-octyl)phosphine oxide; the solid substrate and/or the extraction medium is/are subjected, simultaneously with the contacting operation, to a mechanical action.

Abstract: To control a switch apparatus having two interrupters, such as a busbar disconnector and a grounding disconnector, there is provided a rotary control shaft arranged away from, and at right angles to, the planes of straight line motion of the movable contacts, at least one disk cam fastened to the control shaft and having two distinct internal cam grooves, and two pairs of levers hinged to each other. One of the levers has one end hinged at a fixed point while its other end is hinged to the other lever, which is itself hinged to one of the movable contacts, a spigot being located between the two ends of each of the levers that has one end hinged at a fixed point, the spigot being engaged in one of the cam grooves so as to constitute a cam follower.

Abstract: A sealed stopper for an opening in a junction tubing between an enclosure and a pipe, including an attachment ring. The stopper includes a rigid lid and a sealing assembly borne by the lid including a passive annular gasket including at least one annular internal chamber, a first static annular gasket, a second static annular gasket and a flat gasket ensuring the seal of the opening of the tubing.

Abstract: A vacuum circuit-breaker wherein at least in one of the contacts at least one stud is used as a spacer, and is disposed between the mechanical connection portion and the circular plate of the contact body in such a manner as to avoid the collapse thereof during a closing operation of the vacuum circuit-breaker, and in the closed position the contacts can withstand very high compression forces, typically greater than 700 kg-force or 2 t-force.

Abstract: A vacuum circuit-breaker wherein one contact body is made with two windings implanted concentric with one another and connected electrically in parallel. The second winding is in the form of an solid part with an annular ring. The circuit-breaker increases the axial magnetic field (AMF) and distributes it uniformly over the contact surface so that arc extinction is improved for high short-circuit currents, typically greater than 63 kA.

Abstract: A system for filling a jar with powdery material, for example for the manufacture of nuclear fuel, including a device for connection between the jar and a material feed system, where the device includes: a stationary connection portion connected to the feed system, a connection portion which moves relative to the stationary connection portion intended to be connected to the container's filling orifice, where the moving connection portion includes in the area of a downstream end a lip seal to achieve a tight connection by contact with the contours of the jar's filling orifice and where the said downstream end is connected to the stationary connection portion by a bellows so as to provide mechanical disengagement between the downstream end of the moving connection portion and the stationary connection portion.

Abstract: A sealing device for a device for measuring a fill level in a fluid container, particularly in a pressure container of a nuclear facility, includes at least one thermocouple which is connected by a pressure pipe to the pressure container and a pipeline connected to the pressure pipe to an evaluation unit. The pressure pipe and the pipeline are connected to each other by a pipe screw connection including a central part having two threaded pieces. One threaded piece is connected by a screw connection to a pipe sleeve and the other threaded piece is connected by a further screw connection to the pressure pipe.

Abstract: A method is provided for manufacturing a bundle of plates for a heat exchanger made up of a stack of plates. The method includes reducing by machining the initial thickness of each plate by making at least at the periphery of the plate, at least one connecting shoe having a height greater than the thickness of the machined plate, forming on the central portion of the plate, corrugations, to be superposed pairwise on the plates, connecting the shoes in contact with the plates of each pair through a weld bead, superposing the pairs of plates and connecting the shoes in contact with the pairs of plates through a sealed weld bead by arranging a superposition of open or closed ends for alternate inflow or outflow of said fluid.

Abstract: The aim of the method is to characterize an element (21) comprising a plurality of superposed layers separated from one another by interfaces. It comprises at least the following steps: The element (21) is illuminated with radiation (15) emitted by a source (13); radiation (23) transmitted through the element (21) is collected on a detector (17), this transmitted radiation forming an experimental image of the element (21) on the detector (17), the detector (17) being placed at such a distance from the element (21) that interference fringes appear on the experimental image at the interfaces between the layers; and an approximate value of at least one physical characteristic of at least one given layer is determined by calculation from the experimental image, the determination step being implemented by minimizing the difference between the experimental image and a simulated image of at least part of the experimental image of the element (21).