초록 ▼

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 s

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.

대표청구항 ▼

A method for inspecting a girth weld in a core shroud of a nuclear reactor, comprising the steps of: suspending an inspection tool assembly from the upper rim of the core shroud at a first predetermined gross azimuthal position such that an inspection device incorporated in said inspection tool asse

A method for inspecting a girth weld in a core shroud of a nuclear reactor, comprising the steps of: suspending an inspection tool assembly from the upper rim of the core shroud at a first predetermined gross azimuthal position such that an inspection device incorporated in said inspection tool assembly is located at a predetermined gross elevation relative to a girth weld to be inspected and such that an extension arm incorporated in said inspection tool assembly for supporting said inspection device extends into a space between a jet pump assembly and the core shroud; and scanning said inspection device azimuthally and vertically relative to said inspection tool assembly while said inspection tool assembly is located at said first predetermined gross azimuthal position.