General Electric Company

The United States of America As Represented by the United States Energy

James R Punches

John Geddes Erbes

Robert C Dixon

Henry Peter Offer

Gerald A Deaver

Guy E Singleton

James E Cearley

David L Faulstich

David L Rousar

James A Starr

Samuel Kaplan

Matthew G Garbett

Alan J Chertock

An apparatus and method are provided for servicing an irradiated nuclear control rod underwater in a reactor building servicing pool. A turntable containing a plurality of spaced apart tools is positioned adjacent to the control rod. A first tool aligns the turntable relative to the radioactive roller mounted to the control rod by a radioactive pin therethrough. The turntable is indexable to position a second tool adjacent to the radioactive roller and pin, with the second tool being effective for freeing the radioactive pin from the control rod. The turntable is indexable for positioning a third tool adjacent to the radioactive roller and pin for removing the radioactive pin and the roller from the control rod. In further embodiments of the invention the turntable is further indexable for positioning a fourth tool adjacent to the control rod for reaming the pin aperture through which the radioactive pin was mounted. The turntable further includes a fifth tool which is indexable into position adjacent to the control rod for inserting a replacement roller and replacement pin therein. The replacement pin is secured to the control rod by a sixth tool supported on the turntable which is also indexable into position.

Control rod servicing apparatus and method

In a boiling water nuclear reactor having its core, fuel support casting, and control rod guide tubes removed to expose the core plate, a method for the submerged welding repair and replacement of the control rod drive housing at the bottom extremity of the reactor vessel is disclosed. An alignment device registers to a hole in the core plate and its corresponding guide pin. A control rod drive housing mating fixture on the depending extremity of the shaft of the alignment device precisely fits and mates to the top of the control rod drive housing. The alignment device includes cross electronic levels sealed for submersion which levels remotely transfer through attached wiring the precise angularity between the top of the control rod drive housing on one hand and the corresponding and overlying hole in the core plate on the other hand. For the welding repair process herein, a welding cylinder apparatus fits over the depending end of the shaft of the alignment device. This welding cylinder protrudes downwardly and around the control rod drive housing mating to the stub tube through which the control rod drive housing is inserted. In the embodiment here illustrated, a rotating raceway is provided interior of the chamber for permitting TIG welding unit to traverse around a path for weldment defined at the side of the control rod drive housing and at the top of the stub tube.

Control rod housing alignment and repair method

A refueling mast for a reactor complex includes four generally cylindrical tubes. Each inner tube has vertical grooved tracks formed therein. Each outer tube has a guide roller mounted thereon with grooves which mate with track grooves of a respective track on the adjacent inner tube. Track grooves are cold formed moving a roller die tool up and down each inner tube, while increasing pressure on the incorporated die rollers. This process flattens the inner tube where the tracks are being formed. The grooved tracks and the associated flattening provide the torsional rigidity required on the mast tubes for precise positioning and orientation of fuel elements.

Cylindrical refueling mast with longitudinal guide grooves

In a boiling water nuclear reactor having its core, fuel support casting, and control rod guide tubes removed to expose the core plate, an apparatus and method for the submerged welding repair and replacement of the control rod drive housing at the bottom extremity of the reactor vessel is disclosed. The apparatus registers to a hole in the core plate and its corresponding guide pin. A mating fixture on the depending extremity of the shaft of the apparatus precisely fits and mates to the top of the control rod drive housing. The alignment device includes cross electronic levels sealed for submersion which levels remotely transfer through attached wiring the precise angularity between the top of the control rod drive housing on one hand and the corresponding and overlying hole in the core plate on the other hand. For the welding repair process herein, a welding cylinder apparatus fits over the depending end of the shaft of the alignment device. This welding cylinder protrudes downwardly and around the control rod drive housing mating to the stub tube through which the control rod drive housing is inserted. A rotating raceway is provided interior of the cylinder for permitting TIG welding unit to traverse around a path for weldment defined at the side of the control rod drive housing and at the top of the stub tube.

Control rod housing alignment and repair apparatus

In a boiling water nuclear reactor having its core, fuel support casting, and control rod guide tubes removed to expose the core plate, an apparatus for the repair and replacement of the control rod drive housing at the bottom extremity of the reactor vessel is disclosed. The apparatus registers to a hole in the core plate and its corresponding guide pin. A mating fixture on the depending extremity of the shaft of the apparatus precisely fits and mates to the top of the control rod drive housing. The alignment device includes cross electronic levels sealed for submersion which levels remotely transfer through attached wiring the precise angularity between the top of the control rod drive housing on one hand and the corresponding and overlying hole in the core plate on the other hand.

Control rod housing alignment apparatus

In a boiling water nuclear reactor having its core, fuel support casting, and control rod guide tubes removed to expose the core plate, an apparatus and method for the repair and replacement of the control rod drive housing at the bottom extremity of the reactor vessel is disclosed. The apparatus registers to a hole in the core plate and its corresponding guide pin. A mating fixture on the depending extremity of the shaft of the apparatus precisely fits and mates to the top of the control rod drive housing. The alignment device includes cross electronic levels sealed for submersion which levels remotely transfer through attached wiring the precise angularity between the top of the control rod drive housing on one hand and the corresponding and overlying hole in the core plate on the other hand.

Control rod housing alignment

An accurately formed straight edge member serves as a track for a carriage movable along the length of an elongated component. Distance measuring devices supported by the carriage engage the adjacent surface of the component by which flatness, bow and twist of the component can be determined.

Measuring fixture

A method for spacing fast reactor fuel rods using a wire wrapper improved by orienting the wire-wrapped fuel rods in a unique manner which introduces desirable performance characteristics not attainable by previous wire-wrapped designs. Use of this method in a liquid metal fast breeder reactor results in: (a) improved mechanical performance, (b) improved rod-to-rod contact, (c) reduced steel volume, and (d) improved thermal-hydraulic performance. The method produces a 'locked wrap' design which tends to lock the rods together at each of the wire cluster locations.

Growing community of inventors

San Jose, CA, United States of America

James R Punches