General Electric Company

James Cassidy Donohue

Benedict Kazirskis

James Edgar Burner

Bangalore P Mallikarjuna

Methods and apparatus for mapping pipe and valve bores in a reactor pressure vessel (RPV) of a nuclear reactor are described. In one embodiment of the apparatus, a main bar and an adjustable chuck facilitate positioning of a digital indicator inside a valve bore. In the one embodiment, the main bar is rotatably coupled to the chuck, and the chuck includes four movable jaws. A data acquisition element, which includes a digital indicator, is movably coupled to the main bar and configured to move substantially coaxially to the main bar. To map the circumference of the bore, the main bar and the chuck are inserted into the valve bore, and the chuck is used to center the main bar coaxially within the valve bore. The data acquisition element is positioned at a first location along the main bar, and the main bar is rotated so that the digital indicator maps the circumference of the bore. The data acquisition element is then moved to different locations along the main bar to map the circumference of the bore at different locations.

Methods and apparatus for mapping pipe and valve bores in a nuclear

An apparatus for upgrading/repairing existing piping systems of a nuclear reactor without removal/replacement of the old piping. The process involves the steps of machining a counterbore of exposed corrosion-susceptible material and then depositing a corrosion-resistant weld material, thereby isolating the weld joint from corrosion susceptibility. A tool is inserted into the inside diameter of the piping system through an inspection port, valve body or segment removal. Then a tool mounting fixture equipped with axial and rotational capabilities is positioned in relation to the weld joint and locked in place. The tool mounting fixture remains locked in place throughout the entire repair process. A work surface mapping module is programmed to first gather relative reference points throughout the entire repair region. Upon data acquisition completion, the system creates a map of the existing inside diameter configuration. Then in successive stages, a machining head module and a welding head module are respectively manually installed and remotely operated by computer control. The machining and welding processes follow the existing configuration such that upon completion, the final repair blends with the piping inside diameter contour.

Remotely operated, automatic contour mapping, machining and welding

An apparatus for cleaning of a reactor pressure vessel head closure stud. The surface of the stud is cleaned by power vacuum brushing. The stud is hung vertically in a cabinet which supports a vertically elevatable spinner housing. The stud is cleaned in a single process using a rotating wire brush system which is rotatably mounted in the spinner housing and has a central opening for passage of the stud. A plurality of wire bushes are arranged in a circular array surrounding the stud. While the wire brushes are rotating in contact with the stud external surface, the spinner housing and wire brush assembly are displaced vertically by an elevator so that the rotating brushes travel along the full length of the stud. The rotating brushes remove accumulated material on the stud surface. The resulting contaminated debris is contained in a volume enclosed by a brush canister and a bellows. The bellows expands or contracts as the elevator travels. The contaminated debris is drawn into a high-efficiency particulate absolute filter by a vacuum pump.

Apparatus for automated cleaning of reactor pressure vessel closure studs

A method for upgrading/repairing existing piping systems of a nuclear reactor without removal/replacement of the old piping. The process involves the steps of machining a counterbore of exposed corrosion-susceptible material and then depositing a corrosion-resistant weld material, thereby isolating the weld joint from corrosion susceptibility. A tool is inserted into the inside diameter of the piping system through an inspection port, valve body or segment removal. Then a tool mounting fixture equipped with axial and rotational capabilities is positioned in relation to the weld joint and locked in place. The tool mounting fixture remains locked in place throughout the entire repair process. A work surface mapping module is programmed to first gather relative reference points throughout the entire repair region. Upon data acquisition completion, the system creates a map of the existing inside diameter configuration. Then in successive stages, a machining head module and a welding head module are respectively manually installed and remotely operated by computer control. The machining and welding processes follow the existing configuration such that upon completion, the final repair blends with the piping inside diameter contour.

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Sharon Hill, PA, United States of America

James Cassidy Donohue