Abstract: Vertical segments of a side wall of a crucible for an induction furnace are assembled at an adjustable, invariable position by screws screwed into tapped holes of a flange common to all segments. A precise assembly is thus obtained producing no deformation and no internal stresses. The segments are coated with a ceramic coating for their protection and to prevent formation of electric arcs. Junction edges of faces are rounded to achieve the same effect. Water cooling boxes of the lower furnace hearth are similarly constructed. The apparatus can, as an example, be applied to vitrification techniques.

Abstract: Process for combustion and vitrification of waste in which at least one oxygen plasma jet is associated with a continuous melting device by high frequency direct induction (4). The crucible is composed of a continuous external shell (1) and a sole plate (2), both cooled by a liquid circulating in internal channels. The inductor is placed below the sole plate. There is a gravity drain valve at the bottom or on the side.

Abstract: An electromagnetic induction detector (9) is used to check the weld (6) of a plug (3) to a nuclear fuel cladding (2) still containing a spring (5). A weld made using an excessive energy weakens the metallurgical structure of the spring (5) which may reduce the electromagnetic coupling and the signal recorded by the detector (9). A comparison between the peak values of the signal and the plateau value of the signal gives a criterion for estimating the quality of the fuel rods (1).

Abstract: The device comprises a detector (15) of radiation that could be neutron radiation and a detector (16) of another type of radiation, for example gamma radiation. The process consists in deducing a burn up fraction or irradiation of the nuclear fuel (26) by the measurement of the measured value of a radiation, while assuming that the fuel has a defined composition. One deduces from this the activity of the other radiation that one should obtain, and the accuracy of the assumption of the composition of the fuel if the measured value is close to this deduced value. The device (1), which makes it possible to obtain satisfactory measurements in a water filled storage bay (26), is fitted with means for attaching it to a boom (3) and for positioning it (6, 9) in a given position on a fuel storage cell structure (4). The device is displaced towards each fuel element.

Abstract: The present invention provides: a method of drying metallic waste having pyrophoric tendencies (liable to catch fire and/or explode), said waste being for compacting; an apparatus for drying said waste, the apparatus including a compacting canister and being suitable for implementing said drying method; and a canister for compacting said waste, the canister being particularly adapted to implementing said drying method.

Abstract: The invention concerns the production of a chemical sensor which can be used to measure nitric acidity. This sensor is produced using a sol-gel method for depositing a porous film, containing a colored indicator, on the core of an optic fiber. The pH of the initial sol is adjusted as are other conditions for implementing the sol-gel method to obtain stability of the signal (curves 1 to 4) emitted by the sensor in an 8N nitric medium for at least 1000 hours.

Abstract: Device for detecting electro-magnetically the level of a material which is conductive, or made conductive, particularly molten glass. The device comprises an inductor (32) creating an alternating current in the material and surrounding the container (24) of the material, at least one magnetic field sensor (52, 54) in the zone delimited by the inductor, this sensor comprising a pair of transductors making it possible to detect the partial differential, along the axis of the inductor, of the radial component of the field, means (68, 70) of demodulating the signals provided by the sensor, demodulation occurring with a phase shift of approximately ?/2 relative to the current supplying the inductor, and means (72, 74, 76) for processing the signals provided by the demodulation means and for providing a signal indicating that the sensor level has been reached by the material.

Abstract: The invention concerns a device (1) for controlling the exterior aspect of fuel rods (2) for nuclear reactors, said device comprising optical means (40) having at least one camera (42, 42?) and linked to an image acquisition and processing system (48) capable of detecting geometric defects present on each rod (2) to be controlled, and further comprising a roughness tester (50) controlled in such a way as to measure the depth of each geometric defect detected by the image acquisition and processing system (48). Moreover, the invention further concerns a method capable of being implemented with the aid of said device (1).

Abstract: Heating tongs (6) are used to cut a sleeve (4) fixed around an opening (1) of a chamber (2) after the objects to be taken out of the chamber have been introduced. Another pair of tongs (9) is placed on the side of the opening (1) to tighten the sleeve (4) and to keep it flat to avoid pleats, to allow ventilation during the preparation and to avoid tension in the sleeve; the latter would compromise the sealing taking place.

Abstract: A gas siphon type reactor (10) is used to carry out a three phase chemical reaction under pressure, such as the reduction of uranyl nitrate to uranous nitrate by hydrogen, in the presence of a catalyst made up of platinum on a silica carrier. The control of the pressure in the reactor (10) is provided by regulating the liquid and gas flow rates from a high-pressure separator (52), into which the liquid and the gas leaving the reactor (10) are routed. The liquid in the reactor (10) is tapped from a lateral branch pipe (32) fitted with a filter (36) and emerging in the upper area (30), behind a profiled wall (34).

Abstract: A rotating plug (4) is installed in a body (1) and can be in different positions in which two lateral drillings come in front of the orifices corresponding to the body (1) or a sampling orifice (18) in front of which a flask is placed. The fluid to be sampled is circulated so that it fills a chamber (12) delimited by the rotating plug (4), and the rotating plug is then turned until one of its drillings is facing the sampling orifice (18) and a piston (11) delimiting the chamber (12) is pushed in to extract the required quantity of the sample. This device is simple and has an excellent seal.

Abstract: A method and apparatus for precisely locating radioactive sources. A pair of visual cameras are oriented in directions so that they have all or part of their field of vision in common. The apparatus also includes an intermediate camera which is sensitive to the radiation to be measured. The visual cameras make it possible to define the position of the details of the environment by a triangulation method and another triangulation is carried out in order to know the position of the sources after having moved the apparatus. Photogrammetry software is used to accomplish these tasks easily.

Abstract: A gas siphon type reactor (10) is used to carry out a three phase chemical reaction under pressure, such as the reduction of uranyl nitrate to uranous nitrate by hydrogen, in the presence of a catalyst made up of platinum on a silica carrier. The control of the pressure in the reactor (10) is provided by regulating the liquid and gas flow rates from a high pressure separator (52), into which the liquid and the gas leaving the reactor (10) are routed. The liquid in the reactor (10) is tapped from a lateral branch pipe (32) fitted with a filter (36) and emerging in the upper area (30), behind a profiled wall (34).

Abstract: Two receptacles open at the top (15, 16), one of which contains objects (17) are put onto a rotating tray (3) under a convex cover (5). They are held in place by an appropriate device (11, 12). The tray and the cover are rotated by one complete turn such that the objects (17) come out of the first receptacle (15), roll under the cover (5) and finally drop into the other receptacle (16).

Abstract: The present invention provides:

Abstract: Inorganic-organic hybrid gels can be employed to extract chemical species such as lanthanides and actinides and their preparation. The gels include a network of inorganic components with the formula: where M is Si, Ti, Zr or Al, wherein organic molecules which can complex the species to be extracted are integrated, with each organic molecule being covalently linked to one or several M atoms in the network. The network is made by a sol-gel process from metallic alkoxides functionalized with complexing groups (amino, ether, hydroxy, amido, pyridino and bipyridino), capable of extracting metals such as lanthanides and actinides.

Abstract: Dangerous wastes, such as very low level radioactive waste are processed and compacted under the form of flat cakes (12) stacked in metallic drums (10) closed by an intermediary lid (16) provided with a cap. A blocking material is then injected into the drum by an injection nozzle (42), after a toothed crown (38) surrounding this nozzle has perforated the cap. The toothed crown (38) is carried by a dynamic containment hood (28) in which there is also a circuit (44) for negative pressure application to the drum (10) and the hood. This circuit sucks out the contaminated air contained in the tank when it is perforated and during injection. The operation is thus carried out without risk of contaminating the workshop and the external surface of the drum.

Abstract: The invention relates to a process for preparing a castable powder of uranium dioxide UO2, for use in the manufacture of MOX fuel. This process comprises the following stages: 1) to prepare an aqueous suspension of a powder of UO2 obtained by dry process from uranium hexafluoride, said suspension comprising 50 to 80% by weight of UO2 and at least one additive chosen among deflocculation agents, organic binders, hydrogen peroxide H2O2 and a powder of U3O8, in such a quantity that the viscosity of the suspension does not exceed 250 mPa.sec, and 2) to atomise this suspension and dry it in a hot gas, at a temperature of 150 to 300° C., to obtain a castable powder of UO2 with an average particle size of 20 to 100 &mgr;m.

Abstract: A phosphosilicate apatite useful as a confinement matrix for radioactive waste, and having the formula: MtCaxLnyHfwPuz−w(PO4)6−u(SiO4)uF2  (I) wherein: M represents an alkaline metal, Ln represents at least one cation selected from lanthanides, and t, x, y, z, w and u are such that: 0≦t≦1, 8≦x≦10, 0≦y≦1, 0<z≦0.5, 0≦w≦z, and 0<u≦y+2z, and the total number of positive charges provided by the alkaline metal, Ca, Ln, Hf and Pu cations are equal to 20+u is prepared by a sintering-reaction of a mixture of reagent powders, in a neutral or reducing atmosphere, with application of pressure before or during sintering.

Abstract: The present invention relates to a method for cleaning containment enclosures, and in particular for dedusting them. The invention is implemented with double containment; and suctioning is performed within a removable receptacle.