Abstract: A rotary melting furnace having an enclosure supported for rotation. The enclosure includes a cylindrical shell, a pair of disc-shaped flanges connected to the shell at ends thereof, and a unitary liquid cooling circuit. The shell and the flanges each include a portion of the cooling circuit. The shell portion of the cooling circuit is connected to the flange portions of the cooling circuit by pipes.

Abstract: In order to ensure the cooling of the support ferrule of a vessel, such as the cylindrical internal vessel (14) of a fast neutron nuclear reactor, between said ferrule and an internal wall (20) containing a liquid metal at high temperature is placed a thermal protection apparatus (29). The latter comprises sealed collecting tanks (30) supplied with relatively cold, pressurized liquid metal by means of pipes (32), connected e.g. to the reactor bearing structure (16). This liquid metal is sprayed onto the ferrule by sprayers formed in the collecting tanks. On the side turned towards the wall (20), said tanks support elements (38) of a passive thermal protection structure.

Abstract: A device for suspending a core cover from a sealing slab of a fast neutron nuclear reactor of the type comprising a vertically axed vessel structure filled with liquid metal, closed by the slab and containing the reactor core. The device comprises an upper row and a lower row of superimposed, generally flat, planar, metal plates enabling the rows to be joined to the slab and to the core cover, each row of plates defining a closed convex envelope. The plates are flexible in a direction radial relative to the envelope, while being rigid in a direction circumferential with respect to the envelope. The two rows of flexible plates are interconnected by a lattice of rigid bars in an "X" or "V" form. The upper row plates have upper edges rigidly fixed in position relative to the slab and lower edges rigidly fixed in position relative to the lattice. The lower row plates have upper edges rigidly fixed in position relative to the lattice and lower edges rigidly fixed in position relative to the core cover.

Abstract: Core cover plug for a liquid metal-cooled nuclear reactor.It comprises a structure constituted in part by suspension elements fixed to the lower plate of the small rotary plug, and in part by control rod sleeve elements and a conical deflecting plate positioned directly above the core. The suspension elements, which can either be rod sleeves or rigid tie rods, support the sleeve elements by means of one or more grids constituted by intersecting vertical plates. The deflecting plate, which itself carries a group of sampling tubes, is fixed to certain sleeve elements by a connection permitting radial sliding.

Abstract: The invention relates to an apparatus for handling nuclear fuel assemblies, as well as to an assembly for use with such an apparatus.The apparatus comprises a vertically axed guide tube in which is displaced a grapnel, suspended on a flexible connection such as a chain, under the action of a reduction gear. As the grapnel is immobilized in rotation in the guide tube, an assembly is gripped by means of a bayonet system by controlling the rotation of the guide tube-grapnel assembly by a reduction gear. The apparatus can in particular be suspended on the small and/or large rotary plug of a fast neutron nuclear reactor. It can also be used in a handling hod under gas.

Abstract: A heat exchanger of the type incorporating an auxiliary cooling device includes an envelope with inlet and outlet windows for conducting a primary heat transfer medium through the envelope. A bundle of heat exchange tubes is mounted in the envelope with corresponding first ends of those tubes being located adjacent to the inlet window and corresponding second ends of the tubes being located adjacent to the outlet window. First and second collectors are in fluid communication with the tube ends for conducting a second heat transfer medium through the tubes. The auxiliary cooling device is positioned in the inlet window and surrounds the tube first ends and a ferrule projecting upwards from the envelope from the inlet window therein surrounds the cooling device to direct the primary heat transfer medium through the cooling device and into the inlet window of the envelope.

Abstract: Fast neutron nuclear reactor, which comprises a vessel containing a liquid cooling metal, a core immersed in this metal, the vessel having a flooring on which rests a structure for the core, said core being constituted by a juxtapositioning of assemblies fixed into the structure, the liquid cooling metal circulating in an upwards manner in the core, the liquid metal being called "cold liquid metal" before its circulation in the core and "hot liquid metal" after it has passed into the latter, wherein it comprises a fuel element storage structure, which is independent of the core structure and is arranged concentrically with respect to the latter and rests on the flooring, a circulation of cold liquid metal being ensured in the assembly by recovering leaks of the core structure.

Abstract: A steam generator for transferring the heat carried by a liquid metal to a water - steam circuit. It comprises a drainage tank directly suspended at the lower end of the envelope. A drainage tube connected to the bottom of the envelope is disposed within the tank and carries a burster disk at its end. This disk is placed behind a detachable observation window, fixed to the drainage tank and permitting the replacement thereof.

Abstract: Liquid metal-cooled nuclear reactor incorporating a main vessel sealed by a slab and containing the reactor core, an inner vessel placed within the main vessel and defining in the latter a hot zone filled with relatively hot liquid metal and a cold zone filled with relatively cold liquid metal, at least one pump for circulating the liquid metal between the cold zone and the hot zone across the core and at least one heat exchanger disposed between the hot zone and the cold zone, wherein the inner vessel comprises two truncated cone-shaped ferrules opposed by their large bases and a small diameter cylindrical ferrule extending the small base of the upper truncated cone-shaped ferrule, the reactor core resting on the small base of the lower truncated cone-shaped ferrule by means of a support structure, the hot zone being formed within the inner vessel, while the cold zone is formed between the main vessel and the inner vessel.

Abstract: Installation for handling the assemblies of a fast neutron nuclear reactor comprising a core located in a vertically axed vessel and constituted by a group of assemblies positioned in a supporting grid, a horizontal slab over the vessel, a large rotary plug in the slab, a small rotary plug in the large rotary plug and off-centered with respect to the latter, and a handling pot or container making it possible to remove the fuel elements from the vessel, wherein the small rotary plug has a handling poker and the large rotary plug positioned coaxially with respect to the core has a handling arm, the poker making it possible to reach a fraction of assemblies, particularly those in the central part of the core and to transfer them into a take-up station of the supporting grid, the assemblies placed in the take-up station, as well as those in the peripheral area downwardly accessible to the handling arm being deposited by the latter in the handling pot or container.

Abstract: Heat exchanger for a nuclear reactor of the type in which the main vessel is sealed by an upper slab, comprises a plurality of substantially straight exchange tubes mounted between on the one hand an upper annular tube plate associated with a secondary fluid discharge chamber and on the other a lower annular tube plate associated with a supply chamber, a ferrule surrounding the said tubes and provided with a discharge orifice for the primary fluid, a central shaft which communicates with the supply chamber, and a supply manifold and a discharge manifold for the secondary fluid, wherein it comprises a supporting ferrule fixed to the periphery of the upper tube plate and sealed at its upper end by a dome, said ferrule having on its outer periphery a supporting flange by the said slab, the manifolds being superimposed in the supporting ferrule and fixed to a horizontal plate, which is itself fixed to the supporting ferrule, the supply manifold being connected by at least one pipe to the upper end of the shaft, t

Abstract: Fast neutron nuclear reactor cooled by a liquid metal, comprising a main vessel sealed by an upper slab and within said main vessel at least one heat exchanger between the said liquid metal and a second fluid, at least one pump for circulating the liquid metal, a cylindrical inner vessel with a vertical axis and placed on flooring resting on the bottom of the main vessel, the inner vessel containing the reactor core which rests on a support bearing against the bottom of the main vessel by means of the said flooring, the liquid metal circulating from bottom to top through the reactor core, wherein the said inner vessel incorporates an internal baffle which revolves about the vertical axis of the inner vessel, said baffle comprising an upper cylindrical part adjacent to the inner vessel and arranged above the core, and a lower cylindrical part surrounding the core and having a smaller diameter than the upper part, said lower part being connected to the upper part by a frustum-shaped part, whereby the baffle con

Abstract: Handling device for a fast neutron reactor cooled by a liquid metal such as sodium and of the type comprising a container with a vertical axis containing the core and a given volume of sodium contained in said container, defining above the core a free level surmounted by an inert gas cushion, a thick horizontal slab placed above the gas cushion and constituting the upper closure of a protective caisson surrounding the container, an inclined ramp which passes into the container up to a loading and unloading station located in the vicinity of the core and extending at its opposite end into a handling chamber supported by the slab, a second inclined ramp connecting the inside of the handling chamber to a second loading and unloading station positioned externally of the caisson in a storage container, a carriage carrying a handling pot able to move along the said ramps and moving the pot from a position where it is submerged below the sodium level to a position where it is introduced into the inert gas atmosphere

Abstract: The vehicles are moved in continuous manner in the same direction, on orders of a computer given only before their departure, fixing an itinerary optimized as a function of the congestion anticipated at each section of the network. The network comprises several one-way closed circuit routes, having common zones between convergent and divergent stretches, wherein each of said routes is traversed in one-way sense by guide-marking elements having between themselves, a controlled spacing called the pitch. In the zone common to any two of the routes, the marking elements have the same direction with an interconnected pitch P and speed V, and are shifted in the common zone, from one route to the other, and serve as pilots for the vehicles keyed on them by a servo system during their passage over one route. The vehicles possess a device permitting possible changing of the line of marking elements (hence of the route).