General Electric Company

John J Ashburn

John Geddes Erbes

Michael P Karazim

Bob Y Okashima

Stephen B Bayne

A method and an apparatus for inspecting a core shroud by remote operation. The apparatus is a robotic scanning device which can be installed in the narrow space between the core shroud and the jet pumps and which can scan azimuthally and vertically around the circumference of the core shroud. The scanning device provides gross positioning to the area of interest and precise motion control in a limited scanning range. The scanning uses a thin wide arm to support a bank of transducers at its bottom end, and is rigidly mounted to a precision two-axis positioner at its top end. The arm is of narrow thickness to pass through the 0.5-inch access opening and to allow radial flexibility to absorb surface contour variation over the inspection area. The transducer mounting includes a water jet thruster to provide a radially inwardly directed reaction force to maintain the transducers in contact against the shroud. The arm is fabricated with a row of longitudinal holes extending throughout its length. The transducer leads are routed through some of the holes, providing them with a protective sheath for operation in the confined access. The other holes are used to conduct pressurized water from a pump to operate the jet thrusters.

Narrow access scanning positioner for inspecting core shroud in boiling

An apparatus for underwater separation of a jet pump beam from the inlet mixer of a jet pump in a nuclear reactor system. The apparatus underwater cuts a retaining piece coupling the beam with the inlet mixer.

Growing community of inventors

Livermore, CA, United States of America

John J Ashburn