Abstract: In order to eliminate the need to weld, drill or otherwise machine a shroud structure which is used to surround a plurality of fuel assemblies in a nuclear reactor, a support ring which either seats on top of the upper edge of the shroud, or is formed in multiple segments and is clamped to the side wall of the shroud, have hangers which are rigid therewith on which support hooks can be detachably mounted. The hooks are arranged to be engagable with the inner peripheral wall of the RPV in a manner which prevents lateral movement of the shroud within the pressure vessel.

Abstract: An adjusting and positioning assembly for a bearing element (55), constituted by a nut (52) carried by a base plate, (40) fixed on a wall of a concrete structure in which the component is arranged, and a screw-jack (54) engaged with and blockable with respect to the nut (52). The transverse holding of the lower part of a steam generator pressurized-water nuclear reactor is provided by an assembly of supports each constituted by an adjustable transverse holding device (24) according to the invention. The position of the bearing element is adjusted in such a manner as to maintain play allowing movement of the steam generator as a result of thermal effects or in the event of an earthquake.

Abstract: The irradiated component (1) comprises at least one tubular wall with its axis vertical and fastened inside a well (2) in a concrete structure (3). The connecting elements between the concrete structure (3) and the component (1) are destroyed, the component (1) is displaced in successive steps in the vertical direction along its axis on the inside of the well (2), and the wall of the component is cut, so as to obtain blocks (26) of irradiated material of the wall, at the upper level of the well (2) of the concrete structure (3) after each displacement of the component (1). The cut blocks (26) are disposed of for the purpose of elimination or storage. The displacement of the component can be obtained by a pull or push on its lower bottom.

Abstract: A pressurizer tank in a pressurized water nuclear reactor is mounted between structural walls of the reactor on a substructure of the reactor, the tank extending upwardly from the substructure. For bearing lateral loads such as seismic shocks, a girder substantially encircles the pressurizer tank at a space above the substructure and is coupled to the structural walls via opposed sway struts. Each sway strut is attached at one end to the girder and at an opposite end to one of the structural walls, and the sway struts are oriented substantially horizontally in pairs aligned substantially along tangents to the wall of the circular tank. Preferably, eight sway struts attach to the girder at 90.degree. intervals. A compartment encloses the pressurizer tank and forms the structural wall. The sway struts attach to corners of the compartment for maximum stiffness and load bearing capacity.

Abstract: A nuclear reactor is provided having a generally cylindrical reactor vessel disposed within an opening in a primary shield. The opening in the primary shield is defined by a plurality of generally planar side walls forming a generally polyhedral-shaped opening. The reactor vessel is supported within the opening in the primary shield by reactor vessel supports which are in communication and aligned with central portions of some of the side walls. The reactor vessel is connected to the central portions of the reactor vessel supports. A thermal insulation polyhedron formed from a plurality of slidably insertable and removable generally planar insulation panels substantially surrounds at least a portion of the reactor vessel and is disposed between the reactor vessel and the side walls of the primary shield. The shape of the insulation polyhedron generally corresponds to the shape of the opening in the primary shield.

Abstract: A prestressed pressure vessel safety enclosure is used as a pressure safety enclosure for a nuclear reactor pressure vessel or other primary system vessel containing fluid or gaseous material under high pressure, such as, steam generators, pressurizers and pumps. The special pressure vessel enclosure comprises a first pressure vessel containment assembly surrounding the primary pressure vessel. A pair of first upper and lower pressure vessel jackets are adapted to enclose and be spaced apart, respectively, from the upper and lower portions of the first pressure vessel containment assembly with the rims of the jackets adapted to be slidable and sealed with respect to the first pressure vessel containment assembly. The spaces between the jackets and pressure vessel containment assembly are filled with a high boiling point, low melting point metal.

Abstract: A nuclear reactor system pressure vessel comprises a steel inner liner part, an intermediate insulative layer part and an outer pre-stressed concrete part encasing these parts. Use of the pre-stressed construction allows for construction of pressure vessels of larger size than heretofore, and this coupled with utilization of squatter reactor cores allows natural convective circulation in the reactor vessel of the heated water pool in the higher capacity systems currently being introduced. The reactor pressure vessel because of its suitability allows enhanced natural steam separation in the vessel and eliminates need for use of centrifugal steam separators. The outer vessel part can be a cast single piece structure or it can be an integrated concrete segment assembled structure embodying pre-stressing tendons arranged in various orientations to effect pre-stressing.

Abstract: A reactor pressure vessel is disposed in a reactor containment vessel and is supported by a pedestal having a cylindrical structure. The inside of the reactor containment vessel is divided into upper and lower drywells by means of a diaphragm floor. A line, a cable and a duct are disposed in and between the upper and lower drywells in the reactor containment vessel. The pedestal comprising a plurality of concrete wall sections and a plurality of connecting vent sections which are arranged alternately along a circumferential direction of the cylindrical pedestal, wherein the line, the cable and the duct are arranged in each of the connecting vent sections and a vent pipe is arranged in each of the concrete sections. A vacuum breaker is further disposed in the reactor containment vessel at a portion above the open end of the vent pipe, the vacuum breaker is connected to a fixing pipe for mounting a vacuum breaker to the pedestal and the fixing pipe has one end opened to the drywell.

Abstract: A nuclear reactor includes a spaced sidewall and a core shroud defining a flow passage for channeling a coolant. A foreign object separator includes an arcuate endwall extending from the sidewall, with the core shroud including an intermediate portion spaced from the endwall to define an annular inlet for receiving coolant from the flow passage. The core shroud also includes a distal end spaced from the endwall to define a throat. A separator member has a proximal end joined to the endwall, and a distal end spaced from the core shroud to define an outlet. The distal end of the separator is spaced from its proximal end for allowing the coolant from the throat to impinge against the separator member for turning the coolant prior to discharge from the outlet and using centrifugal force to separate any foreign objects of predetermined size from the coolant. The separated foreign objects are retained adjacent to the separator member proximal end.

Abstract: A carbonized composite foam having a density less than about 50 mg/cm.sup.3 and individual cell sizes no greater than about 1 .mu.m in diameter is described, and the process of making it.

Abstract: A support system is provided for a pressurizer relief and safety valve system in a nuclear power plant. The pressurizer has a generally cylindrical vessel wall topped with a dome-like member. The valve system includes a manifold generally located above and extending about the periphery of the vessel wall of the pressurizer.The valve support system comprises a plurality of paired lug members that extend outwardly from and are secured to the vessel wall at points spaced around the wall periphery. V-shaped columnar supports extend vertically upward from each of the lug pairs to the valve system manifold.A structural pin extends in the horizontal direction to support a base portion of each of the columnar supports relative to the associated lug pair. Disengageable locking clamps secure the pin to the lugs. A pair of diagonal columns extend upwardly in a V-shape from the support base portion to the manifold. A crossbar connects the diagonal columns at the top of each columnar support.

Abstract: The pump apparatus comprises a pump, suction device and a pressure container. The suction device is constructed as a structural unit and can be inserted coaxially from above into the pressure container. The pump likewise is constructed as a structural unit which can be inserted from above with self-centering and self-sealing connections coaxially into a hollow compartment of the suction device and is connectable therewith. By means of threaded bolts which, upon lowering the suction device, piercingly extend through bores provided at a ring flange of the suction device, the inserted suction device can be connected with the pressure container. If the need exists this can be accomplished by remotely controlled manipulator expedients.

Abstract: Concrete support ledges (67) and columns (94) for the upper internals (60) and lower internals (63) structures are poured into the floor (41) and walls (36) of the refueling cavity (33) at the time of initial plant construction. Such concrete supports (67, 94) provide greater stability and do not require any external bracing. A pedestal assembly (100) is associated with each of the concrete supports (67, 94) to provide an adjustable and secure support for the internals structures (60, 63).

Abstract: A liquid metal nuclear reactor has a sodium tank, having a closed arcuate bottom and upstanding cylindrical wall for containing a reactor core in a pool of liquid metal coolant, which is disposed in a guard tank having a bottom and upwardly extending cylindrical shell, and a support inside the guard tank adjacent the closed bottom of the sodium tank to support the two tanks in spaced relationship to each other. The sodium tank has an open top spaced from an overlying closure deck, with the cylindrical shell of the guard tank secured to the closure deck. The support is preferably an inner ledge. Support legs are also provided about the bottom periphery of the guard tank adapted to rest on a base mat of a reactor cavity.

Abstract: A nuclear power plant includes a concrete biological shield, a metallic reactor pressure vessel surrounded by the concrete biological shield, coolant connector pieces connected to the reactor pressure vessel, coolant lines connected to the coolant connector piece, and a support engaging the coolant connector pieces and holding the reactor pressure vessel. The support includes at least one supporting tube surrounding one of the coolant connector pieces, the supporting tube having an inner surface anchored on the one coolant connector piece and an outer surface anchored on the biological shield.

Abstract: A novel concrete core support structure for nuclear reactors is described.

Abstract: An improved shut-down heat removal system for a liquid metal nuclear reactor of the type having a vessel for holding hot and cold pools of liquid sodium is disclosed herein. Generally, the improved system comprises a redan or barrier within the reactor vessel which allows an auxiliary heat exchanger to become immersed in liquid sodium from the hot pool whenever the reactor pump fails to generate a metal-circulating pressure differential between the hot and cold pools of sodium. This redan also defines an alternative circulation path between the hot and cold pools of sodium in order to equilibrate the distribution of the decay heat from the reactor core. The invention may take the form of a redan or barrier that circumscribes the inner wall of the reactor vessel, thereby defining an annular space therebetween.

Abstract: A core support system for a core barrel of a nuclear reactor, which core barrel has a bottom core support plate wherein the core support plate has apertures therethrough about the periphery thereof which communicate with recesses in engagement means for the core support plate, and keys inserted into the core support plate apertures and secured thereto with the lower section of the key extending into the recess of the engagement means. The method of installation enables alignment and securement of the core barrel in the pressure vessel without need for an assembler to enter the area between the core barrel support plate and the bottom of the vessel.

Abstract: A gas cooled high temperature nuclear reactor utilizes an independent cooling system for the safety enclosure surrounding the reactor vessel. The cooling system comprises means for circulating cooling medium at least on the reactor side of a concrete safety enclosure shell and a separate closed cooling loop for circulation of separate cooling medium through a reservoir of the first cooling medium and to the outside of the entire nuclear reactor installation.

Abstract: Antiseismic support structure for the pile block of a fast neutron nuclear reactor.It comprises a concrete covering slab resting on the reactor building structure. The vessel and components of the pile block are suspended on said slab in a well of said structure. The building rests on the ground by means of two superimposed floors, namely an upper floor and a lower floor. The two floors are separated from one another by elastic supports, permitting a horizontal oscillatory displacement with respect to one another with a view of filtering the horizontal components of the earthquake with respect to the vessel. These elastic supports are in particular fretted elastomer supports.

Abstract: A nuclear reactor installation with a high temperture, gas cooled nuclear reactor supported in a cavity on a segmented bottom plate held by a centered point of fixation. The first heat exchangers of the primary circulation loop are arranged in the cavity around the nuclear reactor, with the associated first blowers being supported in first passages of the pressure vessel roof. The second heat exchanger for the removal of the decay heat are arranged similarly, with the associated second blowers located in passages of the pressure vessel bottom. The blowers are equipped with contactless magnetic bearings for the rotors. The drives of the core rods and the reflector rods are designed for a banking operation. Simultaneously, the side reflector is supported by means of radial supports on the thermal side shield elastically and secured against rotation. The measures described provide a simplified configuration without affecting safety.

Abstract: The inner barrel assembly of a pressurized water reactor includes an array of interleaved first and second matrices of respective first and second pluralities of rod guides of corresponding first and second different types, disposed in parallel axial relationship, the bottom ends of the guides being affixed to the top core plate of a lower barrel assembly. A flexible support structure connects the top ends of the rod guides to a lower calandria plate and particularly includes corresponding first and second pluralities of top support plates respectively connected to the rod guides of the first and second different types and having outer peripheries generally corresponding to the respective first and second types of rod guides and inner openings for permitting axial passage therethrough of corresponding, first and second different types of rod clusters.

Abstract: An improved liquid metal nuclear reactor construction has a reactor core and a generally cylindrical reactor vessel for holding a large pool of low pressure liquid metal coolant and housing the core within the pool. The reactor vessel has an open top end, a closed flat bottom end wall and a continuous cylindrical closed side wall interconnecting the top end and bottom end wall. The reactor also has a generally cylindrical concrete containment structure surrounding the reactor vessel and being formed by a cylindrical side wall spaced outwardly from the reactor vessel side wall and a flat base mat spaced below the reactor vessel bottom end wall. A central support pedestal is anchored to the containment structure base mat and extends upwardly therefrom to the reactor vessel and upwardly therefrom to the reactor core so as to support the bottom end wall of the reactor vessel and the lower end of the reactor core in spaced apart relationship above the containment structure base mat.

Abstract: Repair apparatus and a method of repair utilized for securing pressure sensing lines to jet pump diffusers in boiling water nuclear reactors is disclosed. Conventional access is made to the reactor with removal of the jet pump inlet mixer to expose the upwardly disposed frustum-shaped diffuser. The diffuser includes a pressure sensing line mounted by a stand off block. It has been found that this pressure sensing line becomes separated from the diffuser due to vibration and accompanying metal fatigue. A repair is effected by introduction of an arcuate beam configured for live support at each end. This pressure sensing line and stand off block is bracketed by the upper end of a beam to register the line to the stand off block. The lower end of the beam brackets the line and stands off from the diffuser at a second introduced stand off block. The line is provided with two points of support to prevent further dislodging vibration.

Abstract: The invention relates to a nuclear reactor cooled by a liquid metal comprising a vessel (12) containing the reactor core (24), a vessel shaft (18) and a sealing slab (14).The bottom (12a) of the vessel rests on the bottom (52) of the vessel shaft via supports (54) defining between the said two bottoms a space (56) in which circulates a cooling fluid such as air. A skirt (74) surrounds vessel (12) and rests on the vessel shaft bottom (52) for supporting slab (14).Application to the construction of simpler and less expensive fast neutron reactors than those hitherto known.

Abstract: A holddown spring retention assembly for use in a nuclear reactor having a pressure vessel, a core barrel having an upper outwardly extending flange, an inner barrel having an upper outwardly extending flange and an annular holddown spring, the barrels and the spring being installed in the pressure vessel during normal operation, with the inner barrel flange disposed above the core barrel flange and the holddown spring interposed between the core barrel flange and the inner barrel flange, the holddown spring retention assembly is composed of a plurality of assembly units disposed around the periphery of the holddown spring, each unit including a lift lug secured to the outer periphery of the spring and having at least one outwardly radially projecting portion and a hanger secured to the inner barrel flange and having a lower portion suspended below the inner barrel flange and below the radially projecting portion of the lift lug means; the lower portion being arranged to support the radially projecting portio

Abstract: A fast neutron nuclear reactor, in which the main vessel and the slab for sealing said vessel are separately suspended on the upper part of the vessel shaft. An outer ferrule of the slab is directly anchored in the vessel shaft by tie rods and is supported by an annular ring embedded in the concrete. The upper edge of the main vessel is welded beneath the ring, the vessel being supported by a second annular ring embedded in the concrete. The upper faces of the slab and the vessel shaft are consequently at the same level, thereby reducing the heights of the vessel shaft and the safety vessel.

Abstract: The lower end of a nuclear reactor core barrel (16) is laterally stabilized within the reactor pressure vessel (10) by four auxiliary support structures (100) equiangularly disposed about the periphery of the reactor lower hemispherical shell (12). The core barrel lower support plate (18) has keys (122) secured thereto for disposition within recesses (114) defined within crossbeams (102) of the structures (100) through which horizontal radial and tangential forces, as well as severe vertical loads, are transmitted from the core barrel (16) to the reactor vessel (10). Shock absorbers (120) interconnect the keys (122) and the crossbeams (102), and divergent brackets (104) serve to radially space the crossbeam (102) from the shell wall (12) so as to define a vertical coolant flow channel (108) through each structure (100).

Abstract: For holding the reactor core in the confining reactor vessel, a support is disclosed that is structurally independent of the vessel, that is dimensionally accurate and stable, and that comprises tandem tension linkages that act redundantly of one another to maintain stabilized core support even in the unlikely event of the complete failure of one of the linkages. The core support has a mounting platform for the reactor core, and unitary structure including a flange overlying the top edge of the reactor vessels, and a skirt and box beams between the flange and platform for establishing one of the linkages. A plurality of tension rods connect between the deck closing the reactor vessel and the platform for establishing the redundant linkage. Loaded Belleville springs flexibly hold the tension rods at the deck and separable bayonet-type connections hold the tension rods at the platform.

Abstract: A support structure for supporting a pressurizer safety and relief valve system above a pressurizer vessel comprises a ring girder which surrounds the pressurizer vessel wall and is supported on pairs of lugs spaced about the pressurizer wall. The ring girder supports columns for the system at locations spaced from the lugs, and support means in the form of frames distribute the load on the lugs. The frames have upper and lower bars and outer vertical bars, with spaced inner vertical bars. Biasing means are provided to attach the frames to the lugs and distribute the forces, and a projection on the ring girder fits into a groove of a support bar on the upper bar of the frame.

Abstract: A liquid metal cooled nuclear reactor of the kind in which the reactor core is disposed in a pool of liquid metal contained in the inner vessel of a double-walled steel tank supported in a vault having a roof the reactor has the roof supported by a conical support skirt carried by the wall of the vault, a single annular weld securing a main roof member to the skirt, and the conical skirt including a forked part providing inner and outer annular skirt portions from which the inner and outer vessels of the tank are carried respectively.

Abstract: Hydraulic jacks are arranged radially both inside and outside the confinement chamber (EC), substantially on a level with the center of gravity of the boiler (BV, EA) disposed inside. The inside jacks transmit thrust to the boiler via an annular floor (20). The outside jacks transmit thrust to the walls (M) of the hall. The outside jacks are arranged as energy-absorbing dampers. The inside and outside jacks resist fast compression by means of calibrated fluid flow orifices, while they expand readily by means of one way valves and pressure accumulators. The boiler and the confinement chamber stand on a base that is resiliently movable in a horizontal direction relative to the raft (R) of the building. This ensures that the reactor is returned to its normal position once an earthquake is over.

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: A support system for supporting a pressurizer safety and relief valve system above a pressurizer vessel of a pressurized water reactor, which comprises an upper ring section that rests on the dome of the pressurizer, a lower ring section having sleeves attached thereto, and a plurality of arcuate connecting sections, conforming to the shape of the dome. Columnar supports for the valve system are supported in the sleeves on the lower ring and collars are attached to the arcuate sections stabilize the columnar supports.

Abstract: This invention relates to a rigid device for supporting a reactor vessel and steam generators associated therewith. The device consists of a metallic structure comprising, on the one hand, a lower portion serving as a support for the vessel and its associated generators through the medium of square journals fitted in fixed ball-joint bearings with a corresponding square bore and on the other hand, an upper portion 6 which comprises on either side two lateral portions surrounding and holding the generators.

Abstract: Heat retarding closure system for partitions having pressure relief openings formed therein especially in nuclear reactor buildings where main coolant nozzles of a reactor pressure vessel penetrate a biological shield, including lightweight construction closure elements having a side facing the reactor and anchors for holding the closure elements, the closure elements being pushable out of the anchors by an overpressure in a given pressure difference direction on the reactor side, and an outer sealing blowout skin, the closure elements being in the form of heat-retarding cassette inserts having a front surface with a peripheral shearing edge formed thereon resting against the blowout skin, and the blowout skin having a given thickness in the given pressure difference direction enabling the cassette insert to shear off the blowout skin and be pushed out of the anchors when a given pressure difference is at least reached.

Abstract: A support structure for a nuclear power station having a prestressed cylindrical vessel comprising an annular ring of supports on a support wall and foundation wherein the prestressed cylindrical vessel rests on the ring of supports is disclosed. The supports, through their defined distances from each other, provide a constant cooling flow of the supports and a constant temperature over the entire operating period of the power station. This results in supports that are maintenance-free. The supports are constructed of plastic washers with steel inserts and are of sufficient height such that in the case of earthquakes, maximum vibrations of the reinforced concrete pressure vessel may be absorbed within an accurately set terminal boundary of the annular support wall.

Abstract: An anti-earthquake support device arranged between an element of large mass and a fixed support, comprising roller elements arranged between support parts forming roller tracks inclined with respect to the horizontal plane. The roller elements are cylindrical rollers (14,15,17) arranged horizontally in two superposed sets of rollers with perpendicular axes. The support parts (4,10 and 11) are entirely independent of one another and are arranged above one of the sets of roller for the first (4), between the two sets of rollers for the second (10) and beneath the second set of rollers for the third (11). The corresponding roller tracks (9, 20, 21 and 24) are formed on either the lower, or the lower and upper, or the upper surfaces of the three support parts (4, 10 and 11), respectively. The invention is used for the support of a fuel assembly rack for a nuclear reactor on the bottom of the storage pool of such reactor.

Abstract: The present invention relates to a device providing anti-seismic support for an apparatus immersed in the bath of liquid alkali metal surrounding a fast neutron nuclear reactor, and abutting by a flange on a slab traversed by the apparatus and resistant to the load that it constitutes, wherein the flange for supporting the apparatus is connected to a sleeve for elastically taking up the horizontal displacements of its top part, independently of an inner envelope of the apparatus and on which a framework for supporting the apparatus whose bottom part is connected to the inner envelope, is fixed at a level determined as a function of the most dangerous earth tremor frequencies.

Abstract: A liquid metal cooled nuclear reactor of the kind wherein a fuel assembly is supported on a diagrid and submerged in a pool of coolant. The diagrid comprises a plenum supported on a load bearing undershell and has an array of resilient spikes upstanding from the upper face of the plenum each for locating a fuel sub-assembly. The load of the fuel assembly is distributed over the upper face plate of the plenum and transmitted to the undershell by an array of strut members.

Abstract: A supporting floor for the core of a nuclear reactor utilizes a plurality of independent support columns forming the floor of the reactor and resting on the bottom layers of the reactor. The support columns are surrounded by a side reflector which is in turn surrounded by a thermal side shield. Between the thermal side shield and the side reflector are disposed retaining means for maintaining the columns close together and preventing the formation of large gaps during operation.

Abstract: Nuclear boiler comprising a vessel sealed in its upper part by a removable cover, a basket-shaped member carrying the reactor core and separating the vessel into a hot inner area and a cold outer area, at least one steam generator positioned within the vessel and comprising a tightly sealed enclosure and a tube plate separating the enclosure into a primary part or water box and a secondary part, the tube plate carrying U-tubes, whose ends issue into a cold area and a hot area of the water box, defined by an inner structure, two linear, coaxial tubes defining an inner pipe and an annular outer pipe respectively connecting the hot areas and cold areas of the vessel and the water box, wherein a removable safety sleeve, whose wall is designed to resist the pressure in the primary circuit, is arranged coaxially within the outer annular pipe and defines with the latter a calibrated clearance making it possible to limit to a given value the leakage flow if the outer tube fractures.

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: A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

Abstract: The present invention relates to an improved attachment assembly for clamping a nuclear reactor foot ring into engagement with a surrounding support wall while allowing for thermal expansion of the foot ring.

Abstract: A vessel such as a nuclear reactor containment vessel is provided with a bottom extension in the form of a cylindrical skirt in which are formed peripheral openings in uniformly spaced relation. A horizontal cross-pin extends through each orifice, projects on each side of the cylindrical skirt and is provided with means for translational locking with respect to the orifice. The threaded upper portion of an anchor-bolt is mounted at each end of the cross-pin while the lower ends of the two bolts are anchored in the foundation raft. The device produces a substantial reduction of stresses in the anchorage zone.

Abstract: A nuclear reactor with a cylindrical reactor pressure vessel disposed in a reactor cavity formed in a concrete biological shield surrounding and spaced from the pressure vessel includes means for suspending the reactor pressure vessel from the concrete biological shield, the suspending means being a plurality of tension bolts distributed about the periphery of the cylindrical reactor pressure vessel and secured to a corresponding plurality of brackets attached to the cylindrical reactor pressure vessel, the tension bolts extending from the brackets at an inclined angle through the biological shield.