Abstract: Apparatus and method for radiographic inspection of welds, which welds may be seal welds of the kind typically found on nuclear power reactor control rod drive mechanisms (CRDMs). Such CRDM seal welds seal the threaded joint defined by a generally tubular pressure housing and a generally tubular vessel head adapter, the housing and adapter enclosing the CRDM components. The apparatus comprises a circular track capable of surrounding and being connected to the vessel head adapter. A radiation source assembly capable of emitting penetrating radiation and a radiation shielding assembly capable of shielding against the radiation are mounted on the track. The assemblies are adjustable for aligning the assemblies with the seal weld. A radiographic film is interposed between the radiation source assembly and the radiation shielding assembly and adjacent the weld for capturing a volumetric image of the weld on the film.

Abstract: System and method for laser welding an inner surface of a small diameter tubular member. The system includes a laser for generating laser light and a mirror optically coupled to the laser for reflecting the light onto the inner surface of the tubular member to laser weld the inner surface of the tubular member. A rotator assembly is connected to the mirror for rotating the mirror in order to weld around the inner surface of the tubular member. The mirror and rotator assembly are each sized to be disposed in the tubular member at a location adjacent the portion of the tubular member to be welded. The rotator assembly has a spiral groove formed in the exterior thereof for receiving a cord wrapped around the exterior of the rotator assembly. An end of the cord is connected to a motor located externally to the tubular member, so that the cord is pulled as the motor is operated. As the cord is pulled, the rotator assembly rotates for rotating the mirror.

Abstract: Control rod guide tube adapted to reduce vibration of a plurality of control rods disposed therein. The guide tube comprises an elongate housing surrounding the control rods, the housing having an opening at an end thereof for receiving a flowing fluid therethrough. The fluid has a velocity component acting transversely to the control rods sufficient to induce vibration of the control rods. However, the housing of the present invention has an intermediate portion pierced by a plurality of apertures for exit of the fluid from the housing to reduce the velocity of the fluid acting transversely to the control rods in order to reduce vibration of the control rods. As control rod vibration is reduced, control rod wear is mitigated.

Abstract: Vibration dampener for dampening vibration of a tubular member, such as an instrumentation tube of the type found in nuclear reactor pressure vessels. The instrumentation tube is received in an outer tubular member, such as a guide thimble tube. The vibration dampener comprises an annular sleeve which is attachable to the inside surface of the guide thimble tube and which is sized to surround the instrumentation tube. Dimples are attached to the interior wall of the sleeve for radially supporting the instrumentation tube. The wall of the sleeve has a flexible spring member, which is formed from the wall, disposed opposite the dimples for biasing the instrumentation tube into abutment with the dimples. Flow-induced vibration of the instrumentation tube will cause it to move out of contact with the dimples and further engage the spring member, which will flex a predetermined amount and exert a reactive force against the instrumentation tube to restrain its movement.

Abstract: Device and method for thermally insulating a structure to prevent thermal shock therein, which structure may be a feedwater inlet nozzle of the kind typically found on nuclear steam generators. The device comprises a sleeve extending into the bore of the nozzle for thermally insulating the nozzle and joined to the nozzle to affix the sleeve to the nozzle. The sleeve is so joined to the nozzle so as to define a joint therebetween. A liner is concentrically disposed in the sleeve so as to cover the joint to thermally insulate the joint and joined to the sleeve for affixing the liner to the sleeve. The nozzle may have a temperature significantly higher than the cooler feedwater flowing through the bore in the nozzle thereby giving rise to a potential for thermal shock in the nozzle, which thermal shock in turn may induce metal fatigue in the nozzle. The device, as it is disposed in the bore of the nozzle, thermally insulates the nozzle to prevent thermal shock and metal fatigue therein.

Abstract: Stayrod arrangement for enhancing removal of sludge from nuclear heat exchangers. The stayrod arrangement includes a rod disposed adjacent a plurality of heat exchange tubes defining a tube lancing lane therebetween, the tube lane having sludge deposits therein. The rod has planer side portions oriented parallel to the direction of a fluid stream intended to flush the sludge deposits from the tube lane. An anti-rotation connector is connected to the rod for fixing the orientation of the rod with respect to the fluid stream.

Abstract: Calibration arrangement and method for calibrating an inspection instrument, such as an ultrasonic inspection instrument of the kind typically used to inspect nuclear reactor pressure vessels. The calibration arrangement comprises a frame, the frame having a slot therethrough for receiving a sonic coupling medium therein. A plurality of channels extend through the frame and are in communication with the slot. A plurality of solid reflector rods matingly extend through respective ones of the channels and into the slot for reflecting sonic energy produced by a pulsed ultrasonic transducer mounted on the frame and spanning the slot. A pulser stimulates the transducer so that the transducer transmits pulsed sonic energy through the coupling medium which resides in the slot. The sonic energy is reflected by the rods that pass through the slot. The reflected sonic energy or echoes are received by the transducer, which generates transducer output signals that are received by a receiver.

Abstract: System and method for hydraulically expanding tubular members, such as heat transfer tubes and sleeves of the type found in nuclear steam generators. The system includes a resilient ribbed bladder for radially expanding the tube or tubular sleeve that is to be disposed in the tube. The system further includes a pressurizer hydraulically connected to the bladder for supplying pressurized hydraulic fluid to the bladder in order to expand the bladder into intimate engagement with the sleeve and/or tube. The system also includes a controller electrically connected to the pressurizer for controllably operating the pressurizer. The system may further include a fluid supply reservoir fluidly connected to the pressurizer for supplying fluid to the pressurizer and may also include visual display means electrically connected to the controller for displaying the pressure acting on the bladder during the expansion process.

Abstract: Self-locking plug for plugging a hole defined by a surrounding structure, which structure may be a nuclear power reactor pressure vessel core barrel flange. When the hole is plugged, transient hydraulic forces generated in the pressure vessel will tend to force the plug from the hole. The plug includes a plug body sized to be disposed in the hole and a locking member pivotally connected to the plug for locking the plug body to the flange, so that the plug is not inadvertently forced from the hole by the transient hydraulic forces. A cam, which is capable of engaging the locking mechanism for outwardly pivoting the locking mechanism, is slidably connected to the plug body. A movable piston is connected to the cam for driving the cam into engagement with the locking mechanism. Moreover, the locking mechanism pivots to engage the flange as the cam engages the locking member. A ram, which is also connected to the plug body, is provided to ram the plug body into the hole for snugly plugging the hole.

Abstract: Segmented instrumentation tube including a locking sleeve for interlocking the segments of the instrumentation tube, so that the threaded ends of the instrumentation tube do not unthread when subjected to vibration, such an instrumentation tube being suitable for use in a nuclear reactor pressure vessel. The instrumentation tube has a first member having a threaded end portion that has a plurality of first holes circumferentially around the outside surface thereof. The instrumentation tube also has a second member having a threaded end portion that has a plurality of second holes circumferentially around the outside surface thereof. The threads of the second member are caused to threadably engage the threads of the first member for defining a threaded joint therebetween. A sleeve having an inside surface surrounds the end portion of the first member and the end portion of the second member and thus surrounds the threaded joint.

Abstract: Inspection probe for inspecting a tubular member for anomalies, the tubular member having an inside surface that may be irregularly-shaped. The inspection probe includes an enclosure sized to be slidably received along the inside surface of the tubular member. The enclosure has a cavity therein and a housing disposed in the cavity. A spring is disposed in the cavity of the enclosure for outwardly biasing the housing toward the inside surface of the tube. A swivel body is pivotably mounted in the housing. The swivel body has a sensor pivotably mounted thereon for sensing anomalies (i.e., flaws and wall thinning) in the tube wall. Connected to the swivel body and to the sensor is a first pivot pin for pivoting the sensor about a first pivot point laying on a first axis extending transversely to the longitudinal axis of the tubular member.

Abstract: A shielded access door for a nuclear steam generator manway port having a beam of radiation streaming therethrough, the port being surrounded by a manway flange. The door comprises a bracket adapted to be removably connected to the flange. A plurality of swing arms have the first end portion thereof pivotally connected to the bracket. A first shield member is connected to the second end portions of the arms and is disposed parallel and adjacent to the port for shielding against the beam of radiation. The first shield member and the port define a gap therebetween for allowing access to the steam generator interiorly of the port while simultaneously shielding against the beam of radiation. The first shield member has a ventilation hole therethrough in communication with the port for ventilating the port, so that air-borne radioactive particles present interiorly of the steam generator are exhausted from the steam generator.

Abstract: As shown in FIGS. 8 and 9, the instant invention provides a concave filter 530 which comprises two oppositely disposed geotextile fabric sheets 560A and 560B. Fabric sheets 560A and 560B are porous for filtering the liquid from the slurry solids and may be fabricated from a geotextile material such as the material composing filter sheets 330a and 330b (see FIG. 4). Disposed between fabric sheets 560A and 560B is at least one drainage grid 350 such as the drainage grid 350 illustrated in FIGS. 4 and 4A.

Abstract: A flexible cable for carrying an inspection probe along the inside surface of a tube, such as a nuclear steam generator tube, to inspect the tube for anomalies and damage. The cable includes a core member having the inspection probe connected thereto and a plurality of adjacent interconnecting beads surrounding and disposed along the exterior of the core member. Each pair of adjacent beads defines a ball and socket joint for allowing the cable to flex without seizing or doubling-back on itself as the cable is moved in the tube so that the exact location of a tube anomaly can be precisely determined by measuring the length of the cable inserted into the tube.

Abstract: A flux thimble removal tool includes two basic units: a lower pulling unit 20 and a cutting/storage unit 22 which sits atop the lower pulling unit. Pulling unit 20 houses a gripper unit 30a, drive motor 68, gears 32, 66, helix drive shaft 40a, guide bar 26a, slide bar 24a, and guide tube 36, all of which are adapted to gradually extract neutron flux thimbles 38 one at a time from the reactor vessel 74 of a nuclear reactor, and to feed each thimble to the cutting/storage unit 22. The cutting/storage unit 32 further extracts the thimble, then severs the further extracted portion. The operation is continued until the thimble is fully extracted from the reactor vessel and reduced to a pile of easily-disposable segments.

Abstract: Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening.

Abstract: Apparatus for sealing or blocking conduits, such as the primary nozzles of a nuclear steam generator. The invention includes an annular bracket sealingly attached to the rim of the open end of the nozzle, the bracket having a plurality of threaded holes therein. Mounted atop the bracket is a generally circular nozzle dam that includes a first side section hingedly pivotably connected to a second side section for allowing the nozzle dam to be foldable. Removably connected to each side section is a center section, the center section and the side sections defining the generally circular nozzle dam for covering the opening defined by the annular bracket. The periphery portions of the center section and of the side sections have bores therethrough. A plurality of threaded bolts extend through the bores in the nozzle dam and into the threaded holes in the bracket for removably bolting the nozzle dam to the bracket.

Abstract: Adjustable machining apparatus for machining a cylindrical workpiece, such as an electrical generator rotor or stator. The apparatus includes a spindle for holding a cutting tool, which spindle in turn is engaged by a motor for rotating the spindle and cutting tool. Attached to the spindle is a swivel for pivoting the spindle about a pivot point laying on a first axis parallel to the longitudinal axis of the workpiece. A first translation mechanism is attached to the swivel for moving the swivel along a second axis perpendicular to the first axis. A second translation mechanism is connected to the first translation mechanism for moving the first translation mechanism along a third axis transverse to the longitudinal axis of the workpiece. A third translation mechanism is connected to the second translation mechanism for moving the second translation mechanism along a fourth axis paralle to the longitudinal axis of the workpiece.

Abstract: Vessel structural support system for laterally and vertically supporting a vessel, such as a nuclear steam generator having an exterior bottom surface and a side surface thereon. The system includes a bracket connected to the bottom surface. A support column is pivotally connected to the bracket for vertically supporting the steam generator. The system also includes a base pad assembly connected pivotally to the support column for supporting the support column and the steam generator. The base pad assembly, which is capable of being brought to a level position by turning leveling nuts, is anchored to a floor. The system further includes a male key member attached to the side surface of the steam generator and a female stop member attached to an adjacent wall. The male key member and the female stop member coact to laterally support the steam generator.

Abstract: Apparatus and method for dewatering radioactive waste slurry solids. The apparatus includes a vacuum pump for applying a vacuum to a suitable flexible filter and collapsible membrane combination in which the slurry solids are contained so that the slurry solids are compressively dewatered when the vacuum is applied. The apparatus further includes a container for suitably storing the resulting dewatered slurry solids.