Westinghouse Electric Corporation

James R Marshall

Robert E Meuschke

Leonard P Hornak

Robert B Salton

Kenneth J Swidwa

Roy T Hardin, Jr

Michael F Hankinson

Walter E Desmarchais

Leonard R Katz

Thomas L Rohosky

Mary F Thorn

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.

Nuclear reactor containment arrangement with permanent cavity seal ring

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.

Permanent cavity seal ring for a nuclear reactor containment arrangement

A system for transferring fuel assemblies in a nuclear reactor includes a load control system which compares the current load to the more restrictive of fixed overload and underload limits, and instantaneous overload and underload limits continuously calculated from a running average of the measured load. Operation of the refueling machine is terminated if any of these limits are exceeded. The system also accommdates for changes in buoyancy and tension loading applied by spring loaded reels for pneumatic hoses and electrical cables servicing the gripper which engages the fuel assembly as the mast supporting the fuel assembly is raised and lowered in the pool of shielding water covering the reactor core. The current and recent suspended load measurements are displayed relative to the fixed and instantaneous overload and underload limits on a graphic display along with speed and other pertinent data.

Apparatus and method for transferring nuclear reactor fuel assemblies

System provides a positive verification of the presence of a reactor coolant leak in the reactor vessel head area, identifies its location, and enables its size to be determined. A series of video cameras 28 strategically placed about the shroud 16 on the vessel head 13 provide complete viewing coverage. Variable intensity halogen lamps 46, 47 provide illumination for the area to be inspected. The equipment is specially adapted for use in a highly irradiated environment. The system 25 allows for inspection of the reactor vessel head area without the need for shutting down the plant.

Reactor vessel head area monitoring system

A thimble grip fuel assembly handling tool (20) for transporting fully loaded fuel assemblies (52) is disclosed. The tool (20) comprises an elongated mast (23) slidingly disposed within an elongated cylinder (113), the cylinder being of a length less than the mast (23) such that the tool defines a mast fill-up position (126) and a mast full-down position (128). A cage (110) assembly acts to protect the gripping means (32) when the tool is transported in the mast full-up position (126). The gripping means (32) is comprised of a plurality of gripping members (49) which grip the inside diameter of control rod guide thimbles (50). The load path is distributed in the tool such that when the fuel assembly (52) secured to the gripping means (32) is raised, the weight of the fully loaded fuel assembly (52) acts to increase the gripping force on the fuel assembly. A number of indicators on the tool act to indicate to an operator: when the tool is in the mast full-down position; when the gripping members (49) have been fully actuated; and if there is any slipping of the gripping members within the fuel assemblies. The tool also includes a secondary gripping mechanism which engages the top nozzle of the fuel assembly.

Thimble grip fuel assembly handling tool

A high preload quick operating closure for a pressure vessel (17) comprises a vessel opening or nozzle (19) having a port flange (20) with an upper surface (23), which has a wall (26) affixed thereto, the wall (26) having one or more circumferentially spaced holes (32), the combination of the wall (26) and port flange (20) forming a well (29), and a vessel head (27) forming a closure for the port flange. A plurality of wedge assemblies (30) secured to the wall (26) at holes (32), comprising hydraulically operated cylinders (39) operably connected to wedges (33) which slidably engage a tapered surface (40) of the vessel head (27) creating a larger sealing force between the head (27) and the flange (20) to seal the pressure vessel (17) with an enormous preload. The closure incorporates a control system (50) with two independent safety features to prevent the closure device from opening when the pressure vessel ( 17) is pressurized.

High preload quick operating closure

A position sensing mechanism, for use with a nuclear fuel transfer system which employs an underwater cart having a pivotable container to receive fuel assemblies, employs mechanical elements below water and a cable which carries movement of the mechanical elements to a switch assembly at a dry location. The mechanical elements include an anchor element which is affixed to an upender mechanism, which selectively moves the container between horizontal and upended positions when the cart is located at a fuel transfer station, and a feeler mechanism which is displaced by the cart. The feeler mechanism includes a pivotably mounted swing arm and one or more pulleys. The cable is attached to the anchor elements and is guided by the pulleys. The switch assembly includes a further pulley having cams to actuate microswitches when the cable is displaced by the anchor element and feeler mechanism. A temperature compensator is spliced into the cable to keep its length constant despite temperature variations.

Position sensing mechanism for a nuclear fuel transfer system

An annular ring seal for establishing a permanent seal across an annular thermal expansion gap defined between a peripheral wall of a nuclear reactor vessel and a containment wall, which containment wall is spaced apart and surrounds the peripheral wall of the reactor vessel, which collectively define a nuclear reactor containment arrangement. The annular ring seal comprises an annular ring plate having an outer peripheral surface affixed to the containment wall and an inner peripheral surface proximate the reactor vessel; and a flexure member having an annular base plate, which sealingly engages and is affixed to the annular ring plate near the inner peripheral surface thereof, and having a leg which is joined to and extends upwardly from the annular base plate and which is affixed to the peripheral wall of the reaction vessel to thereby seal the annular thermal expansion gap.

Permanent seal ring for a nuclear reactor cavity

An emergency transfer tube closure for a nuclear reactor well comprising an elongated, vertically-extending, U-shaped guide laterally disposed on each side of the transfer tube, a closure plate vertically disposed between the guides having rollers thereon riding within the guides permitting movement of the closure plate downwardly into sealing engagement with the transfer tube under emergency conditions.

Emergency transfer tube closure and process for sealing transfer tube

A hatch assembly has an annular seat, a hatch cover and a plurality of latching units. Each latching unit has a slidably supported locking bolt movable generally radially inwardly with respect to the annular seat into a hatch cover locking position and generally radially outwardly into a hatch cover releasing position. In the hatch cover locking position at least one length portion of the locking bolt extends over the hatch cover for maintaining the hatch cover on the annular seat. Each latching unit further has a rotary crankshaft, an operating handle torque-transmittingly connected to the crankshaft for applying a locking torque and an opposite, releasing torque thereto; and a coupling mechanism for connecting the crankshaft with the locking bolt and for converting rotary motion of the crankshaft to linear motion of the locking bolt. The coupling mechanism has a spring for transmitting the locking torque from the crankshaft as a radially inwardly oriented resilient force to the locking bolt. The radially inwardly oriented resilient force is resolved to a component force with which the locking bolt presses the hatch cover against the annular seat.

Hatch assembly

A refueling machine within a nuclear reactor facility includes an inner mast or gripper tube (12) to the bottom of which is secured a gripper assembly (16). An actuator tube (20) controls the gripper mechanisms of the gripper assembly (16), and in order to insure proper and accurate alignment of the gripper mechanisms with the fuel assembly nozzles, a television camera (26) is mounted within the actuator tube (20). A television monitor (34) is operatively connected to the television camera (26), the monitor (34) being disposed upon the refueling machine personnel trolley. The television camera (26) is removably mounted within the actuator tube (20) by a bayonet-type system which includes camera housing lugs (78) which are adapted to pass through slots (76), subsequent to which the camera housing (28) and the lugs (78) are rotated 90.degree. whereby the lugs (78) are seated within recesses (80). The mounting system further includes shock absorbing spring systems (52, 62) for isolating the camera (26 ) for vertically upwardly and vertically downwardly directed shock loads.

Quick release cushioned T.V. camera mount

A refueling machine (10, 100) within a nuclear reactor facility includes an outer stationary mast (12, 112) upon which are mounted a plurality of light sources (28, 128), inclined mirrors (36, 136), and television cameras (24, 124) for scanning a fuel assembly (32) for the existence of any defects or damage as the fuel assembly (32) is being withdrawn from the reactor core into the stationary mast (12, 112). In a first embodiment, the light sources (28), mirrors (36), and cameras (24) are mounted upon a sleeve (14) clamped about the lower end of the stationary mast (12), while in a second embodiment, the light sources (128), mirrors (136), and cameras (124) are mounted upon a basket-type framework (178) which is suspendingly supported upon the stationary mast (112) by support cables (158). A fixture (176) can support the framework (178) in an off-the-mast mode so as to permit remote-controlled maintenance or repair of the light sources ( 128), mirrors (136), or cameras (124). The mirrors (36, 136) may be eliminated and the light sources re-oriented so as to illuminate the reactor core and thereby facilitate the insertion of a fuel assembly (32) within the reactor core. Television monitors and tape recorder apparatus (168) are disposed upon the refueling machine trolley (150) for remote viewing of the scanned fuel assembly or viewing of the reactor core during an insertion mode of the refueling operation.

Refueling machine mounted fuel assembly inspection T.V. cameras

A fuel transfer system for moving nuclear reactor fuel assemblies from a new fuel storage pit to a containment area containing the nuclear reactor, and for transferring spent fuel assemblies under water from the reactor to a spent fuel storage area. The system includes an underwater track which extends through a wall dividing the fuel building from the reactor containment and a car on the track serves as the vehicle for moving fuel assemblies between these two areas. The car is driven by a motor and linkage extending from an operating deck to a chain belt drive on the car. A housing pivotally mounted at its center on the car is hydraulically actuated to vertically receive a fuel assembly which then is rotated to a horizontal position to permit movement through the wall between the containment and fuel building areas. Return to the vertical position provides for fuel assembly removal and the reverse process is repeated when transferring an assembly in the opposite direction. Limit switches used in controlling operation of the system are designed to be replaced from the operating deck when necessary by tools designed for this purpose.

Growing community of inventors

Penn Hills, PA, United States of America

James R Marshall