Abstract: A tie rod for reinforcing a nuclear fuel assembly. The tie rod includes an outer, hollow tubular member that extends from above the top nozzle through the bottom nozzle of the fuel assembly and has an axially split lower tip with an enlarged end and an upper portion having a circumferential threaded region. An inner rod extends axially through the hollow of the outer tube and has a slightly enlarged tip which spreads the split tip of the outer tube to lock the split tip below the lower nozzle of the fuel assembly. A nut is turned down on the upper threaded portion of the outer hollow tube and staked in position to lock the tie rod in position.

Abstract: A tie rod for reinforcing a nuclear fuel assembly. The tie rod includes an outer, hollow tubular member that extends from above the top nozzle through the bottom nozzle of the fuel assembly and has an axially split lower tip with an enlarged end and an upper portion having a circumferential threaded region. An inner rod extends axially through the hollow of the outer tube and has a slightly enlarged tip which spreads the split tip of the outer tube to lock the split tip below the lower nozzle of the fuel assembly. A nut is turned down on the upper threaded portion of the outer hollow tube and staked in position to lock the tie rod in position.

Abstract: Leak-detection system and method for detecting a leaking container. The system includes an enclosure defining a cavity therein surrounding the container, which container may be a nuclear fuel rod having fission products leaking through a breach in the exterior surface of the fuel rod. The fission products are capable of adhering to the exterior surface of the fuel rod as the fission products leak through the breach in the fuel rod. A radiation detector is in communication with the cavity for detecting the fission products leaking through the breach. Moreover, a gas injector is in communication with the cavity for injecting a multiplicity of carrier gas bubbles into the cavity to remove any fission products adhering to the exterior surface of the fuel rod and to carry the fission products removed thereby to the radiation detector. In this manner, the detector detects the leaking fission products even though they may tend to adhere to the exterior surface of the fuel rod.

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 tool for use in installing O-ring seals in the removable head of a nuclear reactor pressure vessel. Disclosed are two embodiments of the tool. One embodiment is adapted to fit within the stud bolt holes of the flange of the removable head of the pressure vessel. The other embodiment is adapted to be magnetically attached to the underside of the flange of the removable head of the pressure vessel. The tool uses a movable support arm to properly position and support the O-rings in their respective grooves machined in the underside of the flange of the removable head.

Abstract: A thimble screw alignment plate is disclosed herein that greatly facilitates the removal and reinstallation of the bottom nozzle of a fuel assembly. The screw alignment plate includes a plurality of bores registrable with the screw holes of a bottom nozzle, and a resilient sleeve mounted over each bore for receiving, retaining and aligning the threaded end of a screw with each such screw hole. The alignment plate is particularly adapted for use in an overall fuel assembly repair and reconstitution system, and greatly expedites the removal of bottom nozzles whose feet include flanges or gussets that obstruct access to one or more of the thimble screws that connect the bottom nozzle to the support skeleton of the fuel assembly.

Abstract: An electromechanical measurement system for acquiring dimensional data from a nuclear fuel assembly includes an underwater measurement assembly, support means for mounting same on the edge of a spent fuel pool, and a control and data acquisition and processing unit. The underwater measurement assembly includes an elongated strongback disposable vertically along a pool wall, adjustment mechanism on a support assembly permitting accurate positioning of the strongback. A support plate carries hydraulic clamps for clamping the top nozzle of a fuel assembly while it is supported from overhead, a clamp carried by the lower end of the strongback being engageable with the bottom nozzle for holding the fuel assembly in a selected orientation with the faces of the top nozzle vertical.

Abstract: Both a grinding tool and a thimble screw alignment plate are disclosed herein that greatly facilitate the removal and reinstallation of the bottom nozzle of a fuel assembly. The grinding tool includes a base plate, a grinding motor, a grinding head, a housing for isolating the grinding motor from ambient water, and both a guide mechanism and linear drive for guiding and pushing the grinding head into abrasive contact with a screw-obstructing portion of a bottom nozzle. The screw alignment plate includes a plurality of bores registrable with the screw holes of a bottom nozzle, and a resilient sleeve mounted over each bore for receiving, retaining and aligning the threaded end of a screw with each such screw hole.

Abstract: A system constructed of three tools for manipulating fuel rods with a nuclear fuel assembly is disclosed. The individual tools are adapted for displacing fuel rods upwardly and downwardly along their longitudinal axes and for rotating same 360.degree. without having to remove the fuel rods from their location within a nuclear fuel assembly. The individual tools are operative on-site from a remote location while the nuclear fuel assembly is maintained underwater in a spent fuel pool. By manipulating the fuel rods, those areas previously hidden from visual inspection such as within grids may be inspected for defects and the like.

Abstract: A light-weight, portable, pipe crawler vehicle includes a four-wheeled chassis, with the sets of wheels along the opposite sides of the chassis being respectively driven by two hydraulic motors. A foldable mast is removably pivotally mounted on the chassis and carries a pneumatic cylinder which, when the mast is in its erected position, forces bearing wheels against the opposite side of the pipe to force the chassis wheels into firm frictional engagement with the pipe so that it can traverse vertical pipe sections while remaining under control. The dimensions of the vehicle are such that when the mast is folded the vehicle will fit through a 16"-diameter manway of a nuclear steam generator vessel. The chassis also carries a three-axis remote manipulator and one or two remotely-controlled video cameras. A position indicator including a star wheel and proximity sensor is disposed for rolling engagement with the pipe to sense distance travelled.

Abstract: The invention comprises a core barrel plug capable of being remotely installed in a port of a core barrel of a pressurized water nuclear reactor for converting the reactor from a by-pass downflow configuration to a by-pass upflow configuration. The plug comprises a body having an expandable cylindrical portion with a movable mandrel disposed in the body. Remote fluid pressurization causes the mandrel to be advanced thus expanding the body into contact with the port. The plug also comprises a locking mechanism to prevent inadvertent release of the plug.

Abstract: The fuel assembly locking apparatus comprises a rotatable plate capable of simultaneously and positively engaging all four legs of the bottom nozzle of a fuel assembly for uniformly holding the fuel assembly while the spent fuel rods are pulled from the fuel assembly. The rotatable plate has four notched corners arranged to be rotated over a ledge on each leg of the bottom nozzle of the fuel assembly thereby preventing movement of the fuel assembly. The rotatable plate is also capable of being rotated 45.degree. so that the four corners of the plate are rotated clear of the legs of the bottom nozzle of the fuel assembly thereby allowing the fuel assembly to be placed on or removed from the locking apparatus. The locking apparatus is also provided with a torque actuator for remotely rotating the plate.

Abstract: The spent fuel consolidation system provides a system for vertically and remotely dismantling an irradiated nuclear fuel assembly while the fuel assembly remains submerged in a coolant and for consolidating the spent fuel rods of the dismantled fuel assembly. The system comprises a platform rotatably mounted on a vertical support with a fuel assembly station, a consolidation station, and a canister station attached to the platform. A gripper mechanism is slidably disposed on the vertical support for transferring spent fuel rods from one station to another as the various stations are rotated into alignment with the gripper mechanism. The fuel assembly station provides a station for holding the fuel assembly while the spent fuel rods are removed therefrom, the consolidation station provides a station for consolidating the spent fuel rods, and the canister station provides a station for holding the consolidated spent fuel rods.

Abstract: A system for removing sludge that may be deposited on a tube sheet of a steam generator. Headers are arranged at the elevation of the sludge to be removed establishing a circumferential fluid stream at that elevation. A fluid lance is moved along the line between the headers emitting a fluid jet perpendicular to the line of movement of the fluid lance at an elevation substantially corresponding to the level of sludge deposits. The fluid jet forces the sludge to the periphery of the tube sheet where the sludge is entrained in and carried away by the circumferential fluid stream.