Abstract: A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

Abstract: The reactor pressure vessel comprises a pipe socket (2) connected to a feed-water supply line (3), in which is disposed a coaxial protective sleeve (5) (thermal sleeve) which expands with changes in temperature. With its outer end the protective sleeve (5) slidably abuts the pipe socket (2) and with its inner end it is connected to a feed-water distributing ring situated in the vessel. A pipe section (10), in which bellows (15) are disposed, is inserted between the outer end of the pipe socket (2) and the feed-water supply line (3). With one end the bellows (15) are tightly connected to the outer end of the protective sleeve (5) and with their other end they are tightly connected to the pipe section (10).

Abstract: The remote manipulation arm includes rigid sections (12, 14, 16) kept at a temperature adapted to their operation by a device comprising a vessel (37, 38, 39) surrounding each rigid section (12, 14, 16) and connected to a high-pressure coolant gas source. The vessel comprises two chambers (92, 94), respectively at high and low pressure, connected together by a discharge hole (102) for the gas. The rigid sections (12, 14, 16) are linked together by joints surrounded by bellows seals (40, 42) supplied by coolant gas from the low-pressure chamber (94) of a vessel (37, 38, 39) adjacent to the bellows seal. The gas circulates in a closed circuit comprising the chambers (92, 94) and the bellows seals (40, 42), absorbing the heat propagated through the remote manipulation arm.

Abstract: A thimble tube for use in a guide the in a nuclear reactor. The thimble tube is an elongated hollow tube having one end closed. The portion of the tube that extends into the reactor is formed from a plurality of sections attached to each other to form the tube in an alternating fashion along the width and length of the tube. The sections are formed from materials having different coefficients of thermal expansion. This causes the thimble tube to warp into supporting contact with the interior of the guide tube at normal reactor operating temperature.

Abstract: A hot pipeline is welded to a flange which is supported by brackets connected to a nozzle. The pipeline with a flange can expand freely radially. Welded to the other end of the flange is a pipe, which can withstand an axial temperature gradient between a temperature T.sub.1 at the pipeline and flange, and a temperature t.sub.2 at a compensator and the nozzle. The axial expansion of pipe is accommodated by the compensator, which is welded to the pipe and at its other end to the nozzle. The pipeline, the flange, the pipe and the compensator are subject to the difference between pressure p.sub.2 in the vessel and the pressure p.sub.1 in the pipeline.

Abstract: An energy producing system employing nuclear fission of fuel in pellets disposed in a boiling liquid to produce superheated vapors.

Abstract: A gas-cooled, high-temperature nuclear reactor includes a metallic core barrel, a graphite or carbon block lining disposed in the core barrel, a hot gas line including an outer pressure-confining metallic pipe and a ceramic flow guidance pipe, insulation separating the metallic pipe from the ceramic pipe, a stub concentric with the hot gas line, a device for detachably connecting the stub to the core barrel, the metallic pipe being tightly disposed in the stub, a device for detachably fastening the metallic pipe to the stub, a sleeve, a device for detachably fastening the sleeve to the lining, a bellows compensator being disposed in the stub and having one end tightly fastened to the stub and another end, and a device for connecting the other end to the sleeve.

Abstract: The invention relates to a gas cooled high temperature reactor located in the cavity of a pressure vessel, with spherical fuel elements, and removal apparatus for fuel elements. The latter is made of at least one ceramic pebble outlet tube extending through the graphite structural parts of the nuclear reactor (bottom reflector, bottom layers) and a number of metal pebble outlet tubes installed through the bottom of the pressure vessel. They are arranged coaxially in the liner of the passage through the vessel. To be able to dismantle the metal pebble outlet tubes, they are constructed of several releasably interconnected tube segments. Between the uppermost tube segment and the corresponding ceramic pebble outlet tube a compensating tube is provided and connected with the tube segment by means of a sliding joint. The other end of the compensating tube is fastened to the thermal bottom shield.

Abstract: Disclosed is a nuclear reactor employing a liquid metal and containing a reactor vessel, and at least one satellite vessel, and a hot and a cold leg connecting means which combine to form a continuous pathway for the flow of the liquid metal between the reactor vessel and the at least one satellite vessel. Each of the hot leg and cold leg connecting means contain a bellows assembly which are readily accessible for repair or replacement without draining the reactor vessel of the liquid metal.

Abstract: Hot gas container, including a pressure-proof metallic outer shell having an inner surface, thermal insulation covering the inner surface in the form of ceramic bodies each having a given surface, the bodies partially axially overlapping each other over at least the larger part of the given surface thereof, and anchors fastening the bodies to the outer shell, the anchors being welded to the outer shell, engaged in recesses formed in the bodies and covered by the outer shell and the bodies.

Abstract: Device for purifying liquid metal coolant for a fast neutron nuclear reactor, comprising a pump (6) for circulating the liquid metal, the metal then being purified and heated after purification, as well as a filter (24) of metallic fibers. It consists of an assembly of annular chambers with a vertical axis, closed at their lower part by a base plate (10) and defined and separated from each other by an assembly of coaxial cylindrical metallic shells. The device comprises, from the exterior inwards, a degassing chamber (12), a chamber enclosing an economizer-exchanger (14, 16), a thermal insulation wall (18), a cooling chamber (20) and a purifying chamber (22) in the central part of which is a filter cartridge (24). In the central part of the cartridge (24) is a channel (25) for collecting the purified liquid metal in communication with a basin (44) for collecting the purified liquid metal rising above the device.

Abstract: The invention relates to a device for thermal protection of a component of a fast-neutron nuclear reactor consisting of at least one shell (10, 11) of a diameter smaller than the diameter of the passage (2) for the component (4) but greater than the diameter of the component (4). The length of the shell (10, 11) fixed under the flange (5) of the component (4) is greater than the slab thickness (1). Circulation of blanket gas (13) is established in the annular space (7) between the component (4) and the passage (2).The invention applies in particular to nuclear reactors cooled with liquid sodium whose upper level is under an argon blanket.

Abstract: A reactor cavity surrounding a reactor coolant inlet or outlet pipe is designed to reduce pressurization of the cavity in the event of a LOCA pipe break therein.

Abstract: A passage through a reinforced concrete pressure vessel is provided, wherein the tolerance ranges required for the fastening of the components in the passage may be produced safely and without excessive expenditures. This is achieved by an arrangement including a lining having a first, outer tube resting against the concrete and a second tube arranged within the first tube.

Abstract: A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

Abstract: The invention relates to a fast neutron nuclear reactor of the integrated type comprising a cylindrical inner vessel.The inner vessel comprises two concentric ferrules and the connection between the hot collector defined within this vessel and the inlet port of the exchangers is brought about by a hot structure forming a heat baffle and supported by the inner ferrule and by a cold structure surrounding the hot structure, supported by the outer ferrule and sealingly connected to the exchanger.Application to the generation of electric power in nuclear power stations.

Abstract: A coupling assembly for joining an inlet nozzle with a conduit assembly extending concentrically therein, to provide a fluid-tight and thermally insulated flow passageway for introducing cold water into a nuclear reactor pressure vessel and the like.The coupling assembly comprises a protective sleeve surrounding the conduit assembly and wedged into abutting contact with an end portion of the conduit assembly and an inner surface of the inlet nozzle to form a fluid-tight seal therebetween. A fluid insulating medium having a decreasing temperature gradient is positioned between a portion of the protective sleeve and the surrounding inlet nozzle to create a similar decreasing temperature gradient within the inlet nozzle, in order to protect the nozzle against thermal shocks resulting from the difference in temperature between the relatively warm reactor pressure vessel surrounding the inlet nozzle and the relatively cold water flowing through the inlet nozzle.