Abstract: Methods and apparatus for performing repairs and inspections in a reactor pressure vessel (RPV) of a nuclear reactor are described. In one embodiment of the apparatus, a support mast facilitates the positioning of tools within the RPV, especially at locations that are extremely difficult to access using known methods and apparatus. In the one embodiment, a mast extends in the reactor pressure vessel and through an opening in the top guide and through an opening in the core plate. The mast includes an outer tube and an inner tube positioned at least partially within the outer tube. The inner tube is connected to a robotic arm. A slot is formed in the outer tube and the slot extends at least partially along the axial length of the mast. The portion of the inner tube positioned at the location of the slot is in free communication with the reactor components when the mast is positioned within the RPV. The robotic arm can access the reactor components through the slot in the outer tube.

Abstract: An integrated apparatus for inspecting the arms of jet pump beams using eddy current technology, while also scanning the borehole region using ultrasound technology. In order to inspect the jet pump beam arms, a special scanner is required to properly move an eddy current coil in two dimensions over the complex machined surface on top of the arms. The scanner has two axes of motion and can perform a raster scan in either direction. The inspection payload, an eddy current probe, moves the length of the scanning axis and then the payload is indexed (i.e., moved a small distance) along the indexing axis. The payload is then moved smoothly back along the length of the scanning axis. Data is collected only during motion along the scanning axis. The scanner has a unique curved track design for maintaining the orientation of the eddy current probe perpendicular to the inspection surface. It allows inspecting the top flat surface and the curved edges of the jet pump beams.

Abstract: An improved flexible coil array for nondestructive reflective-mode eddy-current testing of conductive members is disclosed. The assembly comprises a flexible substrate having a first array of coils formed on one side thereof. The first array of coils are connected in series in parallel columns. One end of each of the rows is connected to a common ground connection, while the other ends of each row are successively connected to a source of excitation energy. A second array of series-connected rows of coils, orthogonal to the columns, is formed on the opposite side of the substrate. Again, one end of each of the rows is connected to a common point while the other end of each of the rows is successively connected to means for detecting a voltage induced on the coils of the row. The voltage will vary if one of the coils is disposed in juxtaposition to a discontinuity of the member to be inspected.