Westinghouse Electric Corporation

John J Wilhelm

Mark E Wylie

Gregory L Calhoun

Stuart L Rieben

Richard M Kobuck

Michael Edward Colbaugh

Robert D Burack

Ralph W Tolino

Arthur W Kramer

Ronald F Antol

Ralph W Kugler

William G Cole

Wayne C Sumpman

Samuel C McCaslin

Thomas H Dent

Anoop Kapoor

Thomas J Crossley

Richard J Bodnar

George W Norris

Harvey D Kucherer

Paul H Dawson

Bruce Rl Cox

Charles L Danley

Fredrick J Klorcyzk

Kenneth D Kolberg

Herman Schemberger

A stud tensioner for tensioning the upright studs which secure the head to a reactor pressure vessel is suspended by a motor operated hoist from a motor operated trolley mounted on a circular rail supported above the studs. A single operator operates the motor operated hoist and motor operated trolley, and manually radially fine aligns the stud tensioner for engagement with a stud through a control handlebar. A pair of side-by-side switches adjacent a first hand grip at one end of the handlebar enable the operator to operate the trolley to move the stud tensioner left or right, while vertically aligned switches adjacent a second hand grip at the other end of the handlebar are used to operate the hoist to raise and lower the stud tensioner. Simultaneously, the operator can radially maneuver the stud tensioner by applying force through the handlebar. An adjustable mount allows the handlebar to be rotated about a horizontal pivot axis and locked into a selected angular position relative to the tensioner.

Apparatus for servicing a reactor such as tensioning reactor vessel head

Apparatus and method for loosening a stuck reactor pressure vessel stud. A nuclear reactor pressure vessel has a threaded blind bore therein receiving an upright threaded stud having a centrally disposed passage longitudinally therethrough. A pulsar pump is in communication with the passage for supplying a pulsating liquid into the passage and thence into the bore. As the fluid exits the passage, it will push against the bottom of the bore and exert an upwardly directed hydraulic force against the end of the stud for upwardly lifting the stud. A controller is connected to the pulsar pump for controllably operating the pulsar pump. As the hydraulic force of the pulsating fluid lifts the stud, the fluid will migrate between the threads of the stud and the bore for peening or removing any debris from therebetween and washing it upwardly between the stud and bore to a suction pump in communication with the bore. The suction pump suctions the debris-containing liquid from the bore. The apparatus includes a rotation tool connected to the stud for rotating the stud as the liquid is pulsed in order to enhance removal of the debris from the threads. Removal of the debris allows the stud to rotate with reduced resistance to rotation and with the normal amount of torque applied thereto.

Apparatus and method for loosening a stuck reactor vessel stud

Wheel assembly capable of maintaining engagement with a rail having an uneven portion therein. The wheel assembly includes a frame adapted to pivot about a pivot axis defined by the frame. At least one wheel is rotatably connected to the frame for traversing the rail. The wheel maintains engagement with the rail as the wheel traverses the uneven portion of the rail because the frame pivots about the pivot axis as the wheel encounters the uneven portion of the rail. Service tooling may be suspended from the wheel assembly to service a nuclear reactor pressure vessel located below the rail.

Wheel assembly capable of maintaining engagement with a rail having an

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.

Device for securing a reactor vessel washer to a reactor vessel stud

An improved tube inspection probe is provided of the type that includes a probe head assembly formed from a body member and a sensor holding mechanism for resiliently engaging a sensor against the inner wall of a tube, and a flexible cable connected to the body member for helically moving the probe head assembly through the interior of a tube. The improved probe comprises at least one centering device mounted around the cable for maintaining the axis of rotation of the cable in alignment with the center line of the tube, which includes a plurality of resilient finger members mounted around and extending away from the periphery of an annular member that surrounds the cable, wherein each of the fingers is canted at an acute angle with respect to a line tangent to the periphery of the annular member. The improvement may further comprise a button member resiliently mounted within the probe body in opposition to the resiliently-loaded sensor holding mechanism for maintaining the axis of the probe head assembly in alignment with the center line of the tube during operation, as well as a modular mount for detachably mounting the probe sensor to the sensor holding mechanism to facilitate the replacement or repair of the sensor.

Improved probe for inspecting tubes having mechanism for maintaining

Both an apparatus and method for plugging a conduit, such as a tube in the tubesheet of a nuclear steam generator, is disclosed herein. The plugging apparatus generally comprises an inelastically expandable plug that contains a fluid-receiving cavity, and an expansion means including both a source of pressurized hydraulic fluid and a pull-rod member having a piston for advantageously applying both a radially expansive force and a compressive force to the plug at the same time in order to inelastically expand it into sealing engagement with the inner wall of a tube. In the apparatus of the invention, the compressive force exerted on the plug by the pull-rod member not only serves to inelastically deform the plug into a radially expanded shape, but is also used to seal the open end of the plug so that the pressurized hydraulic fluid admitted within the cavity of the plug will not escape. Both the apparatus and method of the invention are particularly well suited for installing plugs in tubes surrounded by relatively inelastic structures, such as tubesheets. Additionally, the invention conveniently and reliably plugs small diameter tubes in the peripheral regions of these tubesheets.

Apparatus and method for plugging a tube

An axial alignment aid for remote control operations and related method are provided. A mirror located on a first movable member gathers light from its field of view in front of the first member and reflects it at right angles to a beam splitter which reflects the light at right angles to a video camera on the first member. A laser, also on the first member, projects a thin beam of light through a beam expander and a beam-expander lens template which gives the projected beam a pattern. The beam then reflects off another mirror, passes through the beam-splitter and is reflected off the original mirror. The beam is then projected on-axis with the first member (coincidentally on-axis with the video camera's field of view), and is inverted to match the original pattern. A reflective visual indicator or target is mounted on a second member so that its optical axis is collinear with the axis of the second member. An off-axis rotation of the first member to the right of the operator's perspective will result in a back-projected laser spot to the right of center on the visual indicator's front surface. On the other hand, rotation of the first member to the left of the operator's perspective will cause the spot to appear to the left of center on the front surface. Finally, if the operator centers the back-projected spot on the front surface of the visual indicator by moving the first member via a feedback control circuit, the laser light will be reflected exactly on axis with the center of the visual indicator. Positive indication of precise alignment of the first and second members is thus achieved and the first member can be safely and accurately docked with the second member.

Axial alignment aid for remote control operations and related method

A plugging apparatus and method utilizing a plug expander that is hydraulically assisted. The apparatus generally comprises a plug shell having a closed end and an open end, an expander element contained within the shell which is movable between the open and closed ends thereof for wedgingly engaging the shell and radially expanding it, and an expansion mechanism including a combination pull rod and expansion mandrel that is connected to the expander element contained within the shell. A source of pressurized hydraulic fluid is connected to the combination pull rod and mandrel. The mandrel is capable of conducting pressurized hydraulic fluid between the closed end of the shell and the expander element in order to facilitate the movement of the expander element toward the open end of the shell. The invention may be used to conveniently and effectively plug heat exchanger tubes of either nuclear or fossil fuel steam generators.

Plugging apparatus and method using a hydraulically assisted plug

A nozzle dam for providing a fluid-tight seal across a primary fluid nozzle in the plenum of a nuclear steam generating vessel includes two fluid-impermeable seals, each comprising a circular three-section foldable seal plate covered with a flexible diaphragm and circumferentially encompassed by an inflatable seal member disposable in frictional sealing engagement with the inner surface of the nozzle. The two seal apparatuses are interconnected by a central tubular coupling coaxial with the nozzle and non-rotatably fixed to each seal, the coupling having a quick-disconnect feature operable from outside the nozzle dam. The coupling provides a conduit for inflation of one of the seals. The two seals are also interconnected by four post assemblies to maintain the seal plates parallel with each other, each post assembly including a cylindrical member pivotally movable between a release position and a supporting position, and provided with a slidable encompassing sleeve to lock it in the supporting position. Structure is provided for pressurizing the inter-seal space and monitoring the pressure in that space.

Dual seal nozzle dam and alignment means therefor

A nozzle dam for providing a fluid-tight seal across a primary fluid nozzle in the plenum of a nuclear steam generating vessel includes an elongated shaft coupled at one end thereof to an anchor assembly frictionally engageable with the inner surface of the nozzle to anchor the dam in place and a fluid-impermeable seal apparatus coupled to the shaft and closing the nozzle and frictionally engageable with the inner surface thereof to form a fluid-tight seal. The seal apparatus includes a circular plate disposable in wedging frictional engagement with a frustoconical portion of the nozzle inner surface. The shaft extends through a central aperture in the plate and is threadedly engaged with a nut which holds the plate in place. The anchor assembly includes a foldable tripod arrangement coupled to the shaft in such a way that movement of the shaft toward the seal plate effects an increase in the frictional anchoring force. The seal assembly also includes an inflatable portion. In one embodiment this inflatable portion extends around the perimeter of the seal plate and is readily expandable. In another embodiment the inflatable portion includes inflatable pillows disposed between the seal plate and the anchor assembly and inflatable for completely closing the nozzle. A foldable tripod centering mechanism and a shaft tensioning tool are also disclosed.

Non-bolted ringless nozzle dam

The sleeving method comprises inserting a metal sleeve within a tube so as to bridge the defective region of the tube. The sleeve is constructed to have annular slots on the outside thereof that are capable of tightly contacting the inside surface of the defective tube and creating a labyrinth-type seal therebetween. The sleeve is also constructed to have an expander member captured therein that may be pulled through the sleeve thereby causing expansion of those portions of the sleeve having the annular slots therein. Once such a sleeve has been inserted into the defective tube, the sleeve is internally expanded in the area of the sleeve wherein the annular slots are located by pulling the expander member through the sleeve. The expansion of the sleeve in the area wherein the annular slots are located causes the lands between each annular slot to closely contact the inside surface of the tube. The other end of the sleeve can then be either similarly attached to the tube or otherwise attached to the tube.

Sleeving method

The fuel assembly skeleton compaction system provides a means for remotely dismantling an irradiated nuclear fuel assembly skeleton once the nuclear fuel rods have been removed therefrom while the skeleton remains submerged in a coolant. The system comprises a feed chamber for holding the spent fuel assembly skeleton and for feeding a spent fuel assembly skeleton into a shear chamber which is arranged near the feed chamber. The shear chamber contains a shearing device for shearing the skeleton into small pieces and for moving the pieces of the skeleton into a compaction chamber which is located adjacent to the shear chamber. The compaction chamber contains a compaction cylinder for compacting the pieces of the skeleton introduced thereinto. A storage canister is located below the compaction chamber such that when the slide of the compaction chamber is opened, the compacted pieces of the skeleton may be pushed into the storage canister. When the storage canister is filled, it may be remotely removed and replaced with an empty canister.

Fuel assembly skeleton compaction

A camlock for engaging the inside of tubular members thus suspending apparatus from the tubular members comprises a movable spacer disposed on a slidable member between two metal rings. The relative motion of the spacer and slidable member causes the metal rings to be expanded against the inside of the tubular member thereby supporting the apparatus. The metal rings have a thin wall with internal ribs that fit closely to the slidable member. The internal ribs act as stops on the inside of the metal rings so as to prevent their overexpansion.

Expandable camlock

The tube plug comprises a shell having a tapered inner surface against which an externally tapered expander member moves by application of a pulling force. The motion of the expander member relative to the shell causes the shell to expand into contact with a heat exchange tube thereby plugging the tube. The expander member is formed from a hardened metal with tangentially blended leading radius and a self-locking trailing edge which provides for ease in expanding the shell while preventing inadvertent unlocking of the plug. The shell has a substantially uniform wall thickness throughout the portion of the shell which experiences expansion so that the force necessary to perform the expanding process does not increase beyond the strength limitations of the installation equipment as the expander member is moved through the shell. The shell also has a plurality of lands on the outside surface thereof whose depth increases from closed end to open end of the shell so that a uniform wall thickness can be maintained in that region while allowing the lands to contact the inner surface of the heat exchange tube.

Tube plug

The plug installation apparatus comprises a mechanism for moving an internally captured expander member relative to the shell wherein it is captured thereby expanding the plug into contact with the internal surface of a tube within which the plug is disposed. The apparatus further comprises a sensor mechanism for determining that the plug has been properly inserted in the tube prior to expanding the plug for preventing improper expansion of the plug. The apparatus also comprises force measuring devices for determining and verifying that the proper amount of force has been applied to the expander member.

Growing community of inventors

New Kensington, PA, United States of America

John J Wilhelm