General Electric Company

Gerald A Deaver

John Geddes Erbes

Robert C Dixon

Siamak Bourbour

Henry Peter Offer

Barry Hal Koepke

James R Punches

Guy E Singleton

Anh Ngoc Nguyen

James Walton Pyron

James H Terhune

Frank Ortega

James Edward Charnley

David L Richardson

James C Tung

Kenneth Allan Morgan

David L Major

David Bryan Drendel

Leonard John Sharpless

Arunachalam Mahadevan

Don Schrein

Thomas Edaward Gleason

An apparatus for reinforcing weakened portions of the top guide assembly in a boiling water reactor. The repair apparatus includes a cruciform lattice segment which reinforces the damaged or weakened region of the top guide beam lattice. This cruciform lattice segment is held in place atop the existing top guide with specially designed straps. The cruciform lattice segment and associated straps are arranged so that a beam segment of the cruciform lattice segment bridges the weakened region in the cracked top guide. Thus, the bridging beam segment transmits loads across the weakened region of the top guide. The straps are designed to avoid interference with removal and installation of the fuel assemblies and the control rod blade which is inserted between the fuel assemblies.

Local repair of top guide in boiling water reactor by installation of cruciform beam

Apparatus for supporting the lower elbow assembly of a jet pump in a reactor pressure vessel (RPV) of a nuclear reactor are described. The clamp apparatus includes a lower clamp element and an upper clamp element. The upper and lower elements are configured to be positioned at the interface between the thermal sleeve and the jet pump riser elbow. The upper and lower elements include extended ridges that are configured to fit in circumferential grooves precisely machined into the sleeve-elbow assembly on opposing sides of the interface.

Apparatus for performing jet pump riser pipe repairs

Methods and apparatus for supporting the lower riser assembly of a jet pump in a reactor pressure vessel (RPV) of a nuclear reactor are described. In one embodiment of the apparatus, the clamp apparatus facilitates applying compression force on the elbow. The clamp apparatus includes a lower elbow clamp, a riser clamp, and a bridge. The lower elbow clamp is positioned adjacent an interface between the elbow and the thermal sleeve of the jet pump riser pipe assembly. The riser clamp is secured to the riser pipe of the jet pump riser pipe assembly at a location adjacent an interface between the riser pipe and the elbow. The bridge rigidly couples the lower elbow clamp and the lower clamp so that as the respective clamps are secured to the lower riser assembly, a compression clamping force is placed on the piping and welds at each clamp.

Methods and apparatus for performing jet pump riser pipe repairs

Apparatus for supporting the lower riser assembly of a jet pump in a reactor pressure vessel (RPV) of a nuclear reactor. In one embodiment of the apparatus, the clamp assembly provides structural rigidity to the lower rise assembly. The clamp assembly includes a lower thermal sleeve clamp and a riser clamp. The lower thermal sleeve clamp is positioned adjacent an interface between the elbow and the thermal sleeve of the jet pump riser pipe assembly. The riser clamp is secured to the riser pipe of the jet pump riser pipe assembly at a location adjacent an interface between the riser pipe and the elbow. The lower thermal sleeve clamp and the riser clamp also are coupled to each other so that as the respective clamps are secured to the lower riser assembly.

An auxiliary wedge apparatus configured to couple to the restrainer bracket of a jet pump assembly is described. In one embodiment, the auxiliary wedge apparatus includes a support block configured to couple to the restrainer bracket, and a wedge configured to slidingly couple to a wedge channel in the support block, and to engage the inlet mixer to restore a tight rigid fit-up of the jet pump components. The support block includes a wedge channel having tongues depending from the parallel sides of the channel and a hook shaped portion configured to receive the restrainer bracket. The support block also includes a lock screw to couple the support block to the restrainer bracket. The wedge includes grooves in the parallel sides of the wedge configured to slidingly engage the tongues extending in the wedge channel. The auxiliary wedge apparatus also includes a restraint arm depending from the support block configured to capture the existing set screw in the restrainer bracket to prevent the screw from completely unscrewing.

Jet pump auxiliary wedge

Thermal sleeve assemblies for connecting a core spray line to a reactor safe end without welding. In one embodiment the thermal sleeve assembly includes a t-box junction, a thermal sleeve and a finger assembly. The t-box junction is attached core spray lines and the thermal sleeve. The finger assembly is coupled to the thermal sleeve and includes several fingers. The finger assembly includes a ring which is coupled to the thermal sleeve so that an opening in the ring is aligned with a bore extending through the thermal sleeve. The fingers are substantially L shaped and are attached to the ring so that when the ring is welded to the thermal sleeve second end the fingers extend from the thermal sleeve.

Assemblies and methods for coupling piping to a safe end of a nuclear

A wedge locking support apparatus that applies a downward preload force to a jet pump inlet mixer gravity wedge and is remotely installable without disassembly of the jet pumps is described. The downward force supplied by the wedge locking support apparatus supplements the force supplied by the weight of the gravity wedge and improves the lateral support provided to the inlet mixer by the gravity wedge. The wedge locking support apparatus includes an upper leaf spring assembly configured to engage the gravity wedge bracket, a lower leaf spring assembly slidably coupled to the upper leaf spring assembly and configured to engage the top of the wedge, and a jack bolt coupled to the upper and lower assemblies.

Jet pump wedge locking support apparatus

Pipe connector assembly for replacing a core spray line in a nuclear reactor without field cutting, measuring, or welding such line. In one embodiment, the pipe connector assembly includes a first coupling member, a second coupling member, and at least one locking element. The first coupling member includes a flange, a pipe engaging portion, a spherical convex seat portion, a bore and a stud bore. The second coupling member includes a flange having a spherical concave seat portion for receiving the convex seat portion of the first coupling member, a pipe engaging portion, a bore, and a stud bore. The locking element includes at least one spherical washer and a crimp mechanism and couples the first coupling member and the second coupling member by extending through the flange stud bores. The spherical seat portions allow the coupling members to be rotationally misaligned while remaining to be substantially coaxially aligned thus accommodating additional core spray line length while maintaining a leak tight connection.

Pipe connector assembly

Core spray line riser repair apparatus and methods for axially restraining a reactor core spray line riser to a T-box are described. In one embodiment, the repair apparatus includes a sleeve, a threaded draw bolt extending through the axial bore, and a threaded block. The sleeve includes a substantially cylindrical main body having an axial bore extending therethrough and a flange at one end of the main body. The sleeve is configured to be inserted into the T-box until the flange abuts against the T-box. The draw bolt is configured to extend through the sleeve flange, the sleeve bore, and an opening in the core spray line riser. The draw bolt engages the block to draw the block in tight engagement with the core spray line riser.

Core spray line riser apparatus and methods

Repair assemblies and methods for a jet pump diffuser in a nuclear reactor are described. In one particular embodiment, the diffuser has a substantially conical shape, and the larger diameter end of the diffuser is engaged to a shroud support plate of the reactor. The diffuser further has at least a first portion and a second portion welded together at a weld joint. The assembly, in one embodiment, includes a first c-ring having a first frusto-conical portion and a second substantially planar portion, and a second c-ring having a first frusto-conical portion and a second substantially planar portion. The first and second c-rings are configured, in the one embodiment, so that when the first and second c-rings are operatively positioned, first and second openings in the first c-ring are substantially aligned with first and second openings in the second c-ring, respectively.

Apparatus and methods for repairing jet pump diffusers in a nuclear

Methods for sealing cracks adjacent stub tube attachment welds in a reactor pressure vessel of a nuclear reactor are described. The reactor pressure vessel includes at least one stub tube through which a control rod housing extends. The control rod housing is attached to one end of the stub tube with an upper stub tube attachment weld. In one embodiment, a sidewall of a control rod drive housing is cut at a location below the upper stub tube attachment weld to form a weld passage in the control rod drive housing between the control rod drive housing and the stub tube. A weld is then formed in the weld passage so that it is in physical contact with both the stub tube and the control rod housing, and thus seals the control rod drive housing against the stub tube.

Method for sealing a stub tube in a nuclear reactor

A replacement jet pump diffuser apparatus and method are described. In one embodiment, the replacement diffuser apparatus includes a conical section, a first cylindrical section, and a second cylindrical section. The conical section is welded to the first cylindrical section, and the first cylindrical section is welded to the second cylindrical section. A V-flange is formed at one end of the second cylindrical section. The assembly further includes an adapter having a V-flange formed at one end. The adapter is secured to the second cylindrical section by a band clamp which compresses the V-flanges into contact. The adapter further includes an engagement flange having a plurality of bores extending therethrough. L-bolts extend through the respective bores in the engagement flange, and each L-bolt includes an L-section and a threaded section. Respective nuts threadedly engage the threaded sections of the L-bolts. The L-section of each bolt contacts a lower surface of the shroud support plate.

Apparatus and methods for replacing jet pump diffusers in a nuclear

In a pressure vessel of a nuclear reactor containing a core assembly enclosed within a core shroud, the core shroud spaced radially inwardly of a pressure vessel wall, with an annular shroud support plate fixed to the pressure vessel wall, wherein a lower end of the shroud is seated on an upper edge of the support plate to create a joint interface further wherein, and a plurality of brackets are secured between the shroud and the shroud support plate, spanning the joint interface.

Mechanically joined replacement shroud for boiling water nuclear reactor

A thermal sleeve for insertion into a feedwater nozzle bore of a reactor pressure vessel for a nuclear reactor is described. In one embodiment, the sleeve includes a substantially cylindrical main body and a substantially cylindrical interference ring. The interference ring has a first secured end and a second free end. The interference ring is connected at the first secured end to an exterior surface of the substantially cylindrical main body. An interference surface is located at the second free end of the ring. The second free end of the cylindrical interference ring is biased so that when the sleeve is positioned in the nozzle bore, the second free end is biased towards the nozzle bore wall. In one embodiment, the second free end is biased into contact with a surface of an outer sleeve which also is positioned in the nozzle bore. The connector, a nozzle safe end wall, the outer sleeve and the inner sleeve cooperate to define a stagnant water area. A first end of the thermal sleeve interfaces with a connector for connecting the sleeve to a feedwater line. A second end of the sleeve interfaces with a feedwater sparger T-box having openings for spraying water delivered by the feedwater line into the RPV.

Feedwater nozzle thermal sleeve

A core spray line assembly for a nuclear reactor is described. In one embodiment, the core spray line assembly includes first and second core spray lines. Each of the core spray lines is substantially located within the reactor pressure vessel and has first and second ends connected to the shroud The first and second core spray lines include an adjustable core spray header and first and second articulating vertical pipe connector. The adjustable core spray header and articulating pipe connectors facilitate fast and easy replacement of existing core spray lines with the present core spray lines.

Growing community of inventors

San Jose, CA, United States of America

Gerald A Deaver