Abstract: A process and apparatus for the transfer out of a tight enclosure of a fluid solution contained in a polluted container (R1). The transfer is accomplished without removing the polluted container from the enclosure and without breaking the seal of the polluted container. After a clean container (R2) is placed in a receptacle (30) normally isolated from the remainder of the enclosure, the solution is transferred into the clean container (R2) vacuum by a needle. Transfer of the clean container out of the enclosure takes place pneumatically following rotation of a casing containing the receptacle.

Abstract: A process for dismantling equipment that is buried, unsheltered, at risk of contamination and possibly is irradiating, and a vessel for implementing this process. According to the invention, buried equipment at risk of contamination, for example, an off-line effluent pipe, is dismantled in sections under cover of a movable vessel (124) placed above the section to be dismantled (12, 14). The invention also concerns a vessel (124) that has a self-supporting structure built around a deck (126) equipped with an elongated central opening (148) giving access to the section to be dismantled (12, 14).

Abstract: Apparatus for measuring the .alpha. activity of a solution and used for determining the plutonium concentration of a solution sampled from an irradiated nuclear fuel reprocessing installation and which comprises a rotary drum (20), which samples a film of solution in a vessel (20), in order to place it in front of a measuring probe (22). Between the probe (22) and the drum (20) is positioned a sealing disk (40) having three positions, which has an effective measuring region (48), a measuring chain quality checking region and a blank measuring region. In order to avoid a solution deposit by condensation on the disk (40) or on the end of the probe (22), a protective gas injection system (49) having passages traversing the vessel cover (16), scavenges the upper face of the sealing disk at three locations corresponding to the three active regions of the latter. A substantially uniform distribution of the gas flow between said three locations is ensured. The protective gas is then sucked in by a tube (122).

Abstract: Process for the conditioning or recycling of used ion cartridges.The invention relates to a process for the treatment of ion cartridges or elements ensuring the treatment of contaminated waters of storage ponds or pools for nuclear reactor fuels. By cartridge transfer and suction means, said treatment consists of extracting the ion exchange resins contained in the cartridge.When the resin has been extracted, a conditioning process makes it possible to decontaminate and then condition, independently of the resinous substance, the metal structure constituting the cartridge.When the resin has been extracted, a recycling process makes it possible to clean the impurities from the metal structure and fill it again with new resin.The invention has applications in the nuclear field and in particular in the field of treatment and conditioning of nuclear waste.

Abstract: The device comprises a cradle (4) having at least one supporting surface on which the object (6) rests, at least one flange (5) pivotably mounted on the cradle (4) and members (14, 16, 20) for locking the flange (5a, 5b) in its turned-down position. The device further comprises a bearing block (38) connected to the flange in an articulated manner, a shoe (40) mounted on the bearing block (38) for limited displacement and having two bearing surfaces (40a) directed towards the object (6), in the turned-down position of the flange, and a leaf spring (41) interposed between the bearing block (38) and the shoe (40).

Abstract: The device (25, 26) comprises a tubular body (40) mounted axially movable on a flange (5) of a transport structure (4) for an object (6), a spring (36) for return of the tubular body (40) towards an unclamped position, an arrangement for manual displacement (19, 20, 16, 21) of the tubular body (40) between its unclamped position and a clamping position, carried by the flange (5), a rod mounted slidably in the axial direction of the tubular body (40) to a limited extent and carrying a shoe (14, 15), and a second spring for elastic return interposed between an abutment fastened to the tubular body (40) and the end of the sliding rod opposite the shoe (14, 15).

Abstract: A mixer-settler is provided which is modulatable and permits use, manipulation and maintenance within a tight, shielded enclosure using a telemanipulator. The mixer-settler is constituted by several modules (M1, M2, M3), which can be reciprocally dismantled by using tight connecting means (19, 20, 21). The inlets and outlets (17, 18) for the heavy and light phases are located on the front face (40) of each module. Regulating members (9, 10, 11) issue onto the upper surface of each module close to the front face (40). Preferably, shield windows (12) make it possible in each case to see the interphase of a stage comprising a mixing chamber (1) and a settling chamber (2). This is completed by a motorization assembly (3) placed above the module. Application to the treatment of radioactive liquids.

Abstract: The fuel element is inserted into a cell, under water, in a pool. Compressed air is injected into the cell so as to drain it of water. A pressure lower than atmospheric pressure is established in the cell and then the gases contained in the cell are subjected to a stream of scavenging air and are collected in a fission product detecting unit. Water is introduced into the cell, the water in the cell is sampled, fission products in the water sample are detected and the fuel element is extracted from the cell if the possible presence of a leak from this fuel element is determined. The detection device comprises a cell having an elongate body delimiting a central housing for a fuel element and end parts. One of the end parts, traversed by a channel in the extension of the housing, receives a cap for opening and closing the channel associated with a remotely controllable opening and closing arrangement.

Abstract: The duplex tube (1) comprises a tubular core (2) and a cladding or covering layer (3) made from an alloy, the base metal of which is identical to the base metal of the alloy constituting the tubular core (2).

Abstract: The nozzle (8) comprises a transverse element consisting of a cross-braced structure (14) comprising wall elements (15) delimiting cells (16) of large dimensions. Ends of a plurality of mutually parallel leaves (18) are fixed to the inside walls of each of the cells (16) so that their faces are substantially parallel to the direction of circulation of the cooling water through the nozzle (8). The leaves (18) provide between them spaces of a width which is less than the size of the particles likely to be entrained in the cooling fluid and to lodge in the fuel assembly.

Abstract: In order to automatically carry out the emptying and rinsing of non-recoverable bottles or flasks (78) made from a perforatable material such as polyethylene and e.g. containing a low activity solution (88), an apparatus is proposed making it possible to pass the inverted bottles under a double-walled needle (44). The needle (44), operated by a jack, perforates the bottom (82) of the flask (78). Compressed air is then injected into the bottle above the solution (88) through the annular passage formed between the walls of the needle (44), so as to discharge the solution through the central passage of the needle. The flask is then rinsed by injecting pressurized water in place of the compressed air. Finally, the rinsing water is discharged by a further compressed air injection. The emptied and rinsed flasks are then passed to a station, where they are directly discharged into a storage drum.

Abstract: So as to unclog a pipe (16) carrying dangerous and accessible substrances after the removal of a movable member (24, 26), this member is replaced by a guiding member (42), a hydraulic shuttle (66) then being introduced into this guiding member, this shuttle being connected to a high pressure hydraulic source (70) through a box (56) equipped with means for washing the shuttle at the time the latter is withdrawn and means for recovering effluent. The shuttle is then conditioned in a winder connected directly on the box (56).

Abstract: For each of the demountable fuel rods (23), the end part of the protective tube (27), which end part is open towards the exterior, has a reduced diameter over a certain length and comprises at least one seating which does or does not pass through its wall. The end part of the fuel rod (23) is integral with a ferrule (34) which is coaxial with the fuel rod and which surrounds the assembly rod (31) of the fuel rod over part of its length. The ferrule (34) is engaged on the reduced-diameter part of the protective tube (27) when the rod (31) is screwed into the bore (28) of the protective tube. Locking against rotation of the fuel rod in the protective tube (27) is ensured by deformation of the ferrule (34) within the openings of the end part of the protective tube (27). The fuel rod is demounted by exerting a torque on it by way of an engagement surface (37), for example of prismatic form, located near the end of the fuel rod.

Abstract: The invention concerns the recovery of Pu (IV) by using crown compounds.According to the invention, the aqueous solution containing the plutonium (IV) is placed in contact with at least one crown compound, for example DCH 18C6, dissolved in an organic diluting agent, such as benzonitrile. In the case where the solution only contains traces of Pu, it is possible to use a crown compound secured to a solid phase, such as silica.The aqueous solution is a concentrated solution of fission products, an effluent originating from an irradiated nuclear fuel reprocessing installation or a concentrated solution of plutonium with americium.

Abstract: The lower end nozzle (1) comprises an adaptor plate (2), supporting feet (3) and a particle retention device (6) consisting of a filter plate pierced with holes and attached to the bottom face of the adaptor plate (2) over a substantial portion of its surface.

Abstract: The invention relates to the use of thioether ligands in accordance with the formula: ##STR1## in which R.sup.1 and R.sup.2, which can be the same or different, represent alkyl radicals, R.sup.3 is an alkyl radical and A represents a divalent radical chosen from among the radicals of formula:--(CH.sub.2).sub.m ----(CH.sub.2).sub.n --X--(CH.sub.2).sub.p -- ##STR2## in which m is equal to 0 or is an integer from 1 to 6, n and p are integers between 1 and 6 and X represents O or S, for recovering the palladium present in a nitric aqueous solution (A.sub.0) for dissolving irradiated nuclear fuel elements.For example, it is possible to use the ligand of formula (I) with A representing CH.sub.2 --S--CH.sub.2 and R.sup.1 and R.sup.2 representing C.sub.10 H.sub.21.

Abstract: A cardiac valve comprises a ring, one or more flaps, the pivoting axis of the latter including two balls partly extending into a ring cavity and a conical flap cavity. This arrangement improves the life of the valve by reducing wear, stresses, friction and facilitates the assembly thereof if the ring is constituted by two concentric members and if the ring cavity extends on either side of the inner member. The invention more particularly applies to artificial valves installed in the heart in place of defective natural valves.

Abstract: The lower connector (10) comprises a transverse element (12) having a box-shaped structure. The transverse element (12) comprises a reticular structure (13) resistant to bending and limited externally by a frame (14), the cross-section of which corresponds substantially to the cross-section of the assembly. The structure (13) has large-size cells. The transverse element comprises, furthermore, a retaining plate (20) pierced with small-size orifices and superposed on and fastened to the recticular structure (13) parallel to the latter and with a spacing (b), to form the upper part of the connector (10) and delimit a free space for steadying the cooling water of the reactor and for recovering debris carried along by the water, forming the hollow central part of the box-shaped structure.

Abstract: The lower connector comprises an adaptor plate of square shape, traversed by water passage orifices, and a filtration plate pierced with holes of small dimensions and abutting against the adaptor plate. The water passage orifices of the adaptor plate are arranged completely symmetrically in relation to the medians and to the diagonals of the adaptor plate. The set of orifices in each of the zones of the adaptor plate limited by a diagonal and a median comprises orifices have an oblong cross-section and, if appropriate, water passage orifices of a different shape. The filtration plate comprises sets of holes of small dimensions arranged in the zones of the plate which come into alignment with the oblong orifices of the adaptor plate.

Abstract: In order to clean a surface (A) located in a hostile medium, use is made of a bush hammer (34) mounted on a remotely controlled vehicle (32). The waste produced by the bush hammer (34) is directly collected by a collecting pipe (12) connected to an exhauster (14). Cyclone separators (22, 24), an electostatic filter (26) and absolute filters (28, 30) arranged in this order on the collecting pipe recover the waste in decreasing size order. The cyclone separators are mounted on two compartments (76, 78) formed in a vessel (80) and each equipped with devices (90, 92, 100, 102, 106, 108) making it possible to inject into the compartments a waste treatment product and to recover the same after filtering. A container (120) is also placed beneath the electrostatic filter (26).