Abstract: An in-core instrumentation system for a reactor module includes a plurality of in-core instruments connected to a containment vessel and a reactor pressure vessel at least partially located within the containment vessel. A reactor core is housed within a lower head that is removably attached to the reactor pressure vessel, and lower ends of the in-core instruments are located within the reactor core. The in-core instruments are configured such that the lower ends are concurrently removed from the reactor core as a result of removing the lower head from the reactor pressure vessel.

Abstract: A nuclear reactor dismantlement system according to an embodiment includes bio-protective concrete including a first space into which a reactor is inserted and a second space that is connected to the first space and is expanded in the first space, a moving device that is positioned in the second space and moves the reactor, and a cutting device that is positioned in the second space and cuts the reactor.

Abstract: An in-core instrumentation system for a reactor module includes a plurality of in-core instruments connected to a containment vessel and a reactor pressure vessel at least partially located within the containment vessel. A reactor core is housed within a lower head that is removably attached to the reactor pressure vessel, and lower ends of the in-core instruments are located within the reactor core. The in-core instruments are configured such that the lower ends are concurrently removed from the reactor core as a result of removing the lower head from the reactor pressure vessel.

Abstract: It is possible to achieve self-support of the fuel assembly without an upper grid plate when the fuel assembly is mounted or replaced, and it is also possible to prevent the fuel assembly from floating during a reactor operation. According to the present invention, the lower portion of the lower tie plate 7 as a part of the fuel assembly 3, which is inserted into the fuel support 9, extends, and a stable member 21 is provided around the extension portion 20, and thereby it is possible to achieve the self-support of the fuel assembly without the upper grid plate. In addition, since an increase in a weight due to extension of the lower portion of the lower tie plate 7 can prevent the floating during the reactor operation, a floating preventing mechanism using the upper grid plate is not necessary.

Abstract: An in-core instrumentation system for a reactor module includes a plurality of in-core instruments connected to a containment vessel and a reactor pressure vessel at least partially located within the containment vessel. A reactor core is housed within a lower head that is removably attached to the reactor pressure vessel, and lower ends of the in-core instruments are located within the reactor core. The in-core instruments are configured such that the lower ends are concurrently removed from the reactor core as a result of removing the lower head from the reactor pressure vessel.

Abstract: Systems and methods for refueling a nuclear reactor that has a reactor core in a reactor pool having a plurality of elongated reactor core components, a fuel pool for storing core components, and a transfer channel connecting the fuel pool to the reactor pool. The method includes retrieving a replacement core component from the fuel pool, and securing the replacement core component in a first compartment of a handover assembly in a vertical position. The method also includes retrieving a spent core component from the reactor core, and securing the spent core component in a second compartment of the handover assembly in a vertical position. The replacement core component is retrieved from the first compartment and installed into the reactor core. The spent core component is retrieved from the second compartment and stored in a storage rack in the fuel pool.

Abstract: Systems and methods for dismantling a nuclear reactor are described. In one aspect the system includes a remotely controlled heavy manipulator (“manipulator”) operatively coupled to a support structure, and a control station in a non-contaminated portion of a workspace. The support structure provides the manipulator with top down access into a bioshield of a nuclear reactor. At least one computing device in the control station provides remote control to perform operations including: (a) dismantling, using the manipulator, a graphite moderator, concrete walls, and a ceiling of the bioshield, the manipulator being provided with automated access to all internal portions of the bioshield; (b) loading, using the manipulator, contaminated graphite blocks from the graphite core and other components from the bioshield into one or more waste containers; and (c) dispersing, using the manipulator, dust suppression and contamination fixing spray to contaminated matter.

Abstract: The invention relates to a sealing element fastening system for at least one sealing element of a pressure vessel, which has at least one opening and a sealing part, in particular a cover, provided for the opening. In the operating state of the pressure vessel each sealing element is at least partially inserted in an accommodating groove in the sealing part and corresponding sealing element fastening devices are positioned in each case in an indentation in the sealing part. The indentations are in each case sealed by a fill element in the operating state of the pressure vessel.

Abstract: Provided is a modular reactor head area assembly. The modular reactor head area assembly is installed on a reactor head, and includes: a seismic support structure that performs functions of lifting, moving and reinstallation of the reactor head and control rod driving apparatuses, cooling of the control rod driving apparatuses, shielding of missile parts, and supporting with respect to a seismic load, and disperses a load applied to the control rod driving apparatuses; an upper module that is an assembly of components located at an upper portion of the seismic support structure for the control rod driving apparatuses; and a lower module that is an assembly of components located at a lower portion of the seismic support structure for the control rod driving apparatuses. The upper module and the lower module are 252 detachably coupled to each other so that maintenance of the control rod driving apparatus can be performed easily.

Abstract: A method for carrying out a reactor internal, comprising steps of: forming a first opening portion in a ceiling of a reactor building at a position directly above an equipment pool in said reactor building; cutting a cylindrical reactor internal surrounding a core in a reactor pressure vessel disposed in said reactor building, at one position in an axial direction; surrounding said cut cylindrical reactor internal with a radiation shield; and carrying out said cylindrical reactor internal surrounded by said radiation shield out of said reactor building through said first opening portion.

Abstract: A maintenance/repair device for reactor internal structure 6 of the present invention includes a device body 6a configured to be fixed on a reactor internal structure 49. Connected to the device body 6a is a welding-part repair mechanism 6b configured to repair a welding part 49a of the reactor internal structure 49. Thus, a welding part 2a of the reactor internal structure 49 can be repaired by the welding-part repair mechanism 6b, while the device body 6a is fixed on the reactor internal structure 49.

Abstract: The machinery system and its application herewith, intended to create an opening in the roof of a Reactor Primary Containment of Generation II and III Nuclear Power Electric Generating Station. This opening is necessary to replace an aging nuclear reactor with a new, safer and more efficient reactor. Generation II and III Nuclear Power Electric Generating Stations include General Electric (GE) Boiling Water Reactor BWR/2, 3, 4, 5 and BWR/6 located in Mark II, and Mark III wet containments and Pressurized Water Reactors manufactured by Westinghouse, Combustion Engineering and Babcock and Wilcox located in dry containments. Until this time, existing reactor replacement was not possible due to Reactor Primary Containment structural enclosure configuration. The Dual Head Vertical Milling Machine System will remove a Reactor Primary Containment Dome Segment thus providing an opening, allowing reactor replacement and the electric generating station to remain operational for an other 40 years and beyond.

Abstract: An integrated reactor missile shield and crane assembly (IRMSCA) is disclosed and claimed. The IRMSCA replaces the existing concrete missile shields and reactor services crane. The IRMSCA is moveable such that the missile shield can be moved away from the reactor head, allowing the integral crane to lift the control rod drive mechanism components and other routine loads at the refueling cavity.

Abstract: A covering element for a reactor core of a nuclear installation provides a secure and tight closure of the reactor core in an operating state and at the same time being simple and cost effective to produce. The covering element is easily disassemblable during maintenance or loading processes and provides good possibilities for intervention in the reactor core. For this purpose, the covering element has a closure head and a separate support ring. The support ring is joined form-lockingly and/or force-lockingly to the closure head.

Abstract: A telescoping guide for extraction and reinsertion support handling of in-core instrument thimble assemblies in the area above the upper support plate in the upper internals of a pressurized water reactor. The telescoping guides extend between the upper ends of the upper internals support columns and an axially movable instrumentation grid assembly which is operable to simultaneously raise the telescoping guides and extract the in-core instrument thimble assemblies from the reactor fuel assemblies.

Abstract: Provided is a modular reactor head area assembly. The modular reactor head area assembly is installed on a reactor head, and includes: a seismic support structure that performs functions of lifting, moving and reinstallation of the reactor head and control rod driving apparatuses, cooling of the control rod driving apparatuses, shielding of missile parts, and supporting with respect to a seismic load, and disperses a load applied to the control rod driving apparatuses; an upper module that is an assembly of components located at an upper portion of the seismic support structure for the control rod driving apparatuses; and a lower module that is an assembly of components located at a lower portion of the seismic support structure for the control rod driving apparatuses. The upper module and the lower module are 252 detachably coupled to each other so that maintenance of the control rod driving apparatus can be performed easily.

Abstract: The core of a pressurized water reactor is assembled in such a way that if the fuel elements on the edge of the core are bent, these fuel elements are oriented such that the bending of the fuel elements points outwards in a convex manner. When the reactor is in operation, forces arise which increase the size of small gaps between the fuel elements at the expense of greater gaps and counteract the bending effect of the fuel elements.

Abstract: A two-part integrated head assembly (100) is disclosed wherein the lower portion (110) attaches to, and is supported by, the reactor vessel closure head (90), and the upper portion (160) is fluidly connected to the lower portion, but is supported externally from the reactor vessel closure head. In the disclosed embodiment, the upper portion includes transverse support beams (170) that engage containment walls (92), for example steam generator walls, to support the upper portion. A duct (150) releasably connects a fan plenum (165) in the upper portion with an annular plenum in the lower portion, such that fans (166) can draw heated air from around the CEDMs (95). In one embodiment, a chiller (168) is provided in the fan plenum to cool the air prior to expelling it in containment. A missile shield (169) is also provided in the upper portion.

Abstract: A head assembly for a reactor pressure vessel includes a removable closure head, an array of control rod drive mechanisms, a seismic support platform, a missile shield assembly and a cooling system for drawing atmospheric air across electromagnetic coil stack assemblies. The cooling system includes: a lower shroud surrounding the coil stack assemblies with an end open to the atmosphere around the CRDMs; a plurality of extending internal ducts disposed within the array of CRDMs upwardly to an upper plenum disposed above the seismic support platform and a plurality of fan assemblies disposed on the upper plenum. The missile shield is disposed within the upper plenum. The cooling system effectively cools the coil stack assemblies during fuel cycles and does not hinder access to the CRDMs during an outage. The head assembly has lift legs for transporting either the entire head assembly as an integral unit or the structure above the seismic support platform a subassembly.

Abstract: A method of servicing a nuclear reactor during a reactor outage is provided. The reactor includes a primary containment vessel and a reactor pressure vessel positioned in the primary containment vessel. The method includes positioning a servicing platform above the reactor pressure vessel and performing predetermined servicing operations on the reactor. The servicing platform includes a frame having a plurality of interconnected beams, a support structure attached to the frame, and a floor attached to a top of the frame. The floor includes a reactor access opening sized to permit access to the reactor pressure vessel. The servicing platform also includes at least one auxiliary platform movably coupled to the frame and extending into the access opening. The at least one auxiliary platform is movable along a perimeter of the access opening of the floor.

Abstract: A reactor pressure vessel supports the flanges of a core barrel assembly and an upper support plate. These flanges have aligned holes for diverting inlet coolant water to the vessel head for cooling the head. The aligned holes have different cross-sectional areas for controlling unexpected backflow of coolant water from the vessel head around the periphery of the upper support plate.

Abstract: An apparatus, transfer cask, system, and method for defueling a nuclear reactor and transferring spent nuclear fuel from a spent nuclear fuel to a storage cask for long terms storage. In one aspect, the invention is an apparatus for use in transferring a canister of spent nuclear fuel from a transfer cask to a storage cask, the apparatus comprising a radiation absorbing shield surrounding a portion of a hole through which the canister can pass; means for securing the apparatus to the top surface of the storage cask; means for securing the bottom surface of the transfer cask to the apparatus; wherein the transfer cask securing means and the storage cask securing means are positioned on the apparatus so that when the apparatus is secured to both the transfer cask and the storage cask, the cavity of the transfer cask, the hole, and the cavity of the storage cask are substantially aligned; and means for moving the bottom lid in a horizontal direction once the bottom lid is unfastened from the bottom surface.

Abstract: A stud enclosure for protecting a stud extending upwardly from a nuclear reactor pressure vessel (RPV) flange has a cylindrical can with a capped end and an open end. The capped end has an axially extending hole with a screw extending therein for fastening the stud enclosure to the stud. A seal ring is disposed adjacent the open end of the cylindrical can for sealing the ring on the RPV flange. A gas valve is disposed in the capped end of the cylindrical can for pressurizing the interior portion of the can with air. The stud enclosure is used to protect the RPV studs after the RPV head has been removed in order to permit access to the interior portions of the RPV.

Abstract: A head assembly of a reactor pressure vessel in an ice condenser plant is retrofitted to permit the assembly to be removed during a later refueling operation in reduced time and with reduced exposure to radiation by operating personnel. The portions of the ductwork ventilation system that originally provided cooling air to CRDMs are removed below the seismic support platform. The original CRDM cooling shroud that surrounds the lower portion of the CRDM assemblies is extended to the seismic support platform. A plenum is mounted on the seismic support platform and in air flow communication with interior portion of the extended CRDM cooling shroud. The plenum fits under the missile shield. Spool pieces are connected between the plenum and the portion of the ductwork adjacent to the seismic support platform.

Abstract: An integrated head assembly (100) is disclosed for a nuclear reactor. The preferred integrated head assembly includes a lift assembly (150) that supports the reactor vessel closure head (90) and integrated head assembly for removal, a separate support structure (202) supported by a ring beam (151) that sits atop the reactor vessel closure head, a shroud assembly (200), a seismic support system (300), a baffle assembly (500), a missile shield (400), and a CRDM cooling system. The CRDM cooling system draws cooling air into the baffle assembly, downwardly past the CRDMs (96), outwardly to upright air ducts (600), upwardly to an upper plenum (680), and out of the assembly through the air fans (190).

Abstract: An integrated head assembly (100) is disclosed for a nuclear reactor. The preferred integrated head assembly includes a lift assembly (150) that supports the reactor vessel closure head (90) and integrated head assembly for removal, a separate support structure (202) supported by a ring beam (151) that sits atop the reactor vessel closure head, a shroud assembly (200), a seismic support system (300), a baffle assembly (500), a missile shield (400), and a CRDM cooling system. The CRDM cooling system draws cooling air into the baffle assembly, downwardly past the CRDMs (96), outwardly to upright air ducts (600), upwardly to an upper plenum (680), and out of the assembly through the air fans (190).

Abstract: An enclosed cutting zone for use in a nuclear power plant. The cutting zone includes a cutting zone barrier and a transfer zone. The cutting zone includes a movable submergible upper rig, an upper inflatable ring supported by the submergible rig; a lower inflatable ring supported by the submergible rig; and a means for coupling the vertically extending edges of the submergible upper rig to form a cutting zone barrier having enclosed sidewalls. The transfer zone includes a movable, submergible upper rig; an upper inflatable ring supported by the submergible rig; and a lower inflatable ring supported by the submergible rig. The transfer zone is coupled to exterior surface of the cutting barrier so as to form a structure having enclosed sidewalls and an open top.

Abstract: A method of performing maintenance on a structural member inside a reactor pressure vessel includes lowering an annular guide rail having a second lug until the guide rail rests on an upper flange of a core shroud provided inside the reactor pressure vessel, detachably mounting the second lug of the guide rail to a first lug mounted on the core shroud, positioning a discharging nozzle at a position at which compressive remaining stress is added to a surface of the core shroud by moving the discharging nozzle in a radial direction and an axial direction of the core shroud by a discharging nozzle moving apparatus mounted on a turnable revolving on the guide rail and discharging water to add compressive remaining stress to a surface of the core shroud from the discharging nozzle.

Abstract: An integral stub tube which simplifies the reactor pressure vessel fabrication process, provides a structural transition between the penetration and head, and facilitates future remote inspection of the attachment weld is described. In one embodiment, a stub tube is machined into the bottom head dome. Specifically, a penetration is formed in the bottom head dome by a bore having a stub tube portion. The stub tube portion has a cylindrical shape and a length of the stub tube portion is selected to provide a transition between a penetration housing and an adjacent portion of bottom head dome. The penetration housing extends through the penetration, in the dome. A weld attaches the stub tube portion to the penetration housing.

Abstract: There is provided a reactor internal equipment hoisting apparatus which is hung down from an upper side of a reactor pressure vessel to hoist reactor internal equipment installed inside the reactor pressure vessel. The hoisting apparatus includes a supporting unit which is hung down from the upper side of the reactor pressure vessel with an overhead travailing crane installed on the ceiling of the reactor building, and an elevating unit which is arranged below the supporting unit. A coupling/fixing unit is provided to the elevating unit to be releasably coupled with a hoisting lug. Power hoist using a wire rope or a chain is provided to the supporting unit. The elevating unit is hung down from the supporting unit via the rope or the chain to be moved vertically. This reactor internal equipment hoisting apparatus is easy in maintenance and storage.

Abstract: An integrated head assembly for a nuclear reactor pressure vessel includes a closure head with CRDM assemblies extending upwardly from the head. A CRDM seismic support disposed above the closure head provides lateral support for the CRDM assemblies. The seismic support also has air flow holes which communicate with the interior of a shroud enclosing the CRDMs and extending upwardly from the closure head to the seismic support. The shroud has an air port in direct air flow communication with the surrounding atmosphere so that the closure head, shroud and seismic support define an air flow passageway directly communicating with the surrounding atmosphere via the air port and without the extensive ductwork and, therefore, with substantially less power. A missile shield disposed above and in air flow communication with the seismic support provides a lightweight, compact physical barrier for removing energy from dislocated objects such as CRDM drive rods.

Abstract: A rigging system for reactor closure head and reactor internals lifts. The system includes a plurality of latchbox pendants attached to the lifting structure of an overhead crane. A first set of a plurality of lifting lugs is attached to the reactor internals, each of the lifting lugs corresponding to one of the plurality of latchboxes. A second set of a plurality of substantially identical lifting lugs, each of the lifting lugs corresponding to one of the plurality of latchboxes, is attached to a plurality of solid rod lifting pendants attached at one end to the reactor closure head. In operation, the latchbox pendants may be rigged once to the overhead crane for handling reactor internals and left in place throughout the entire rigging sequence without changing to turnbuckle pendants for reactor closure head handling.

Abstract: An integrated head assembly for a nuclear reactor pressure vessel includes a closure head with CRDM assemblies extending upwardly from the head. A CRDM seismic support disposed above the closure head provides lateral support for the CRDM assemblies. The seismic support also has air flow holes which communicate with the interior of a shroud enclosing the CRDMs and extending upwardly from the closure head to the seismic support. The shroud has an air port in direct air flow communication with the surrounding atmosphere so that the closure head, shroud and seismic support define an air flow passageway directly communicating with the surrounding atmosphere via the air port and without the extensive ductwork and, therefore, with substantially less power. A missile shield disposed above and in air flow communication with the seismic support provides a lightweight, compact physical barrier for removing energy from dislocated objects such as CRDM drive rods.

Abstract: In order to facilitate refueling operations, cables, which provide control and power linkages between control element drive mechanisms (CEDMS), and a terminal panel supported on a side wall of the reactor cavity, are disposed in a cylindrical extension of a cylindrical enclosure which encloses the CEDMS, with sufficient slack that they can be drawn out of the cylindrical extension through windows and supported on a drawbridge type of arrangement comprised of pivotal window tray type structures which are respectively hingedly connected to the cylindrical extension and either the wall or the terminal panel, and which span the gap between the cylindrical extension and the terminal panel when pivoted to their respective supporting positions.

Abstract: An integrated head assembly for a nuclear reactor pressure vessel includes a closure head with CRDM assemblies extending upwardly from the head. A CRDM seismic support disposed above the closure head provides lateral support for the CRDM assemblies. The seismic support also has air flow holes which communicate with the interior of a shroud enclosing the CRDMs and extending upwardly from the closure head to the seismic support. The shroud has an air port in direct air flow communication with the surrounding atmosphere so that the closure head, shroud and seismic support define an air flow passageway directly communicating with the surrounding atmosphere via the air port and without the extensive ductwork and, therefore, with substantially less power.

Abstract: The reactor-internal equipment handling apparatus (29) can mount and dismount a reactor-internal equipment (5, 70) to and from the reactor pressure vessel (24) quickly. The reactor-internal equipment handling apparatus for a nuclear reactor, hung down from the above the reactor vessel to handle reactor-internal equipment housed in the reactor vessel, comprises: a body frame (31) hung down from above the reactor vessel; a connecting and fixing section (32, 33, 34) provided for the body frame and adapted to be releasably connected to lugs (25) of the reactor-internal equipment; a circular guide rail (28) disposed on the body frame; and a bolt wrench section (36) disposed movably along the circular guide rail.

Abstract: In order to reduce the number of lifts which are required to remove the various equipment normally disposed above the reactor pressure vessel and to make way for refuelling or regular maintenance, the control rod element drive mechanisms are completely enclosed within a cylindrical enclosure which is attached to the head of the pressure vessel. The top of the cylindrical enclosure is closed with a cap-like member which acts as both a missile shield and a head area cable tray. The missile shield, the cylindrical enclosure, the control rod drive mechanisms and the pressure vessel head, are connected to form an integral unit which can be removed in a single lift. Cable trays are pivotally supported on a wall of a building to establish a bridge between the building and the head area cable array and to establish a connection with the control element drive mechanism cables. During lifting, the control element drive mechanism cables are disconnected and the pivotal bridge trays are swung out of the way.

Abstract: A reactor vessel seal for temporarily sealing a reactor pressure vessel from a water-filled refueling canal above the reactor pressure vessel. The reactor vessel seal is installed in place of the removable reactor pressure vessel closure head for inspecting/servicing the reactor vessel. The reactor seal comprises a seal cap having a surface connected to a flange which is complementary to the upper flange of the reactor pressure vessel. A seal is located between the seal cap flange and the upper flange of the reactor pressure vessel. A lifting rig is connected to the seal cap for lifting the seal cap and placing it in position, with the seal cap flange in alignment with the reactor vessel upper flange, such that the seal located between the seal cap flange and the reactor pressure vessel upper flange is compressed by hydrostatic pressure from water in the water-filled refueling canal acting on the surface of the seal cap as water in the reactor pressure vessel is evacuated.

Abstract: A method of refueling a nuclear reactor whereby the drive mechanism is disengaged and removed by activating a jacking mechanism that raises the closure head. The area between the barrier plate and closure head is exhausted through the closure head penetrations. The closure head, upper drive mechanism, and bellows seal are lifted away and transported to a safe area. The barrier plate acts as the primary boundary and each drive and control rod penetration has an elastomer seal preventing excessive tritium gases from escaping. The individual instrumentation plugs are disengaged allowing the corresponding fuel assembly to be sealed and replaced.

Abstract: A cabling arrangement is provided for a nuclear reactor located within a containment. Structure inside the containment is characterized by a wall having a near side surrounding the reactor vessel defining a cavity, an operating deck outside the cavity, a sub-space below the deck and on a far side of the wall spaced from the near side, and an operating area above the deck. The arrangement includes a movable frame supporting a plurality of cables extending through the frame, each connectable at a first end to a head package on the reactor vessel and each having a second end located in the sub-space. The frame is movable, with the cables, between a first position during normal operation of the reactor when the cables are connected to the head package, located outside the sub-space proximate the head package, and a second position during refueling when the cables are disconnected from the head package, located in the sub-space.

Abstract: A nozzle dam automatically latches on an annular ledge surrounding the nozzle opening. A pivotal latch arm on the dam, biased to the locked position is forced toward the unlocked position by a cam on the ledge as the nozzle is pressed on the ledge, and snaps into engagement with the ledge when the dam is fully seated over the opening. A bias arm may be operated by a wrench to pivot the latch arm toward the unlocked position until a detent locks the latch arm in the unlocked position.

Abstract: A device for removably securing a reactor vessel washer to a reactor vessel stud for use in combination with a reactor vessel including a dome having a first flange positioned abutting a second flange of a reactor body, a plurality of reactor studs are disposed in both the first and second flanges and a nut and washer arrangement secured to the stud for rigidly attaching the dome to the body. The device comprises a retainer removably disposed on the stud and operable to mate the washer to the stud to maintain the positional relationship of the stud and washer as the stud is removed from the dome and the body.

Abstract: A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted.

Abstract: A HP/LP seal arrangement is provided for a guide tube and thimble extending outwardly from the core of a nuclear reactor to a seal table where the guide tube is welded to the seal table to provide a high pressure seal relative thereto. A tubular seal fitting is disposed in alignment with the guide tube with the thimble extending therethrough on the low pressure side of the seal table.A first high pressure seal couples one end of the fitting to an end of the guide tube to prevent leakage from within the guide tube. Inwardly facing threading is disposed adjacent the other and outer end of the seal fitting. A nut is disposed about the thimble and it is provided with outwardly facing threading in mating engagement with the fitting threading.The fitting has a seal seat spaced longitudinally inwardly from the threading and facing the fitting outer end and extending annularly about the inner surface of the fitting.

Abstract: An annular seal ring between a reactor pressure vessel and a containment wall is disposed in an annular expansion gap therebetween, having a support ring and inner and outer upwardly extending cylindrical sections. The inner cylindrical section is disposed below a flange on the reactor and has a flexible seal therebetween, while the outer cylindrical section terminates substantially parallel and spaced from a shelf in the containment wall with a flexible seal therebetween. The annular seal ring is supported by radial support beams, while support rods depending from the support ring position neutron shielding material in the annular expansion gap. Manways and ports provide access to the gap and thermal insulation is provided below the neutron shielding material to direct cooling air from the annular gap up through opened manway and port.

Abstract: A nuclear reactor containment arrangement has a permanent cavity ring seal extending across an annular expansion gap between a reactor pressure vessel and a containment wall to provide a water tight seal therebetween. The annular ring seal has a support ring with an inner downwardly extending cylindrical section resting on the reactor flange and an outer downwardly extending cylindrical section resting on a shelf in the containment wall. A vertically extending, L-shaped, seal extends between an inner end of the support ring while a vertically extending, L-shaped, seal extends between the outer cylindrical section and the containment wall shelf. Neutron shielding material is suspended, by support rods, within the annular expansion gap while thermal insulation is provided therebelow. Manways and ports in the support ring are sealed by hatches and provide access to the annular expansion gap and, while open, provide for flow of cooling air from the annular expansion gap through the support ring.

Abstract: A temporary support structure for supporting a lower internals assembly above the reactor vessel during inspection and/or maintenance thereof. A support bracket is bolted to the reactor vessel flange at the vessel head stud closure holes. A pivotally mounted arm, upon the top surface of which the internals rest, is attached at one end to the support bracket and projects radially inwardly therefrom. A compliant foot depends from the bottom of the opposite end of the arm and engages the vessel internals support ledge to provide a secure support structure for the internals assembly. An alignment bracket on the arm aligns the internals with the support. Four such structures are installed around the circumference of the vessel flange while the internals are within the reactor vessel. The structure allows the lower internals to be quickly removed from the interior of the reactor vessel and placed on the temporary supports.

Abstract: A wiring installation for electrical connections of a plurality of devices of a nuclear reactor, comprising: (a) a plurality of first multiwire cables each extending at least from certain ones of said devices and terminated with a first connector located above said cover at an end remote from said device, and (b) a plurality of second multiwire cables each for connection with a respective one of the first cables and each having a first section having a first multicables connector having a plurality of electrical contacts connected to respective wires of said section, said first multicables connector being common to at least ten independent first sections, and a second section having a second multicables connector having a plurality of electrical contacts connected to respective wires of said second section and corresponding to respective wires of said first section for removable connection to said first multicables connector.

Abstract: An integrated head package for a nuclear reactor has a pressure vessel closure head with control rod drive mechanisms thereon enclosed in a shroud, and a plurality of vertical lift rods secured to the vessel head with a missile shield plate extrending between the lift rods and vertically slidably retained between spaced stop members adjacent the upper ends of the lift rods. A lift rig is secured to the missile shield plate, preferably through attachment to support blocks secured to the upper surface of the plate. Impact forces of a missile against the lower surface of the missile shield plate are transferred to a lifting force and are not transferred to the lifting rods, head lugs, closure studs and pressure vessel supports.

Abstract: A remotely controlled tooling apparatus is disclosed for supporting and selectively disposing a tool with respect to a workpiece illustratively taking the form of a core barrel of a nuclear reactor. Illustratively, a core barrel is of a substantially cylindrical configuration and has a plurality of flow holes disposed therethrough. The remotely controlled apparatus comprises a tool carriage, a support table carried thereby for receiving the tool, a strongback assembly for supporting and guiding the tool carriage with respect to the core barrel, and a pair of clamps affixed to the strongback assembly for engaging the core barrel for suspending the strongback assembly upon the core barrel. The tool carriage and its support table carried thereby are selectively disposed with respect to the core barrel, whereby the tool may be engaged and disengaged with and from the core barrel.