Abstract: A system for remotely repairing nuclear fuel rod assemblies is disclosed herein. Generally, the system comprises a rod handler for gripping, lifting, lowering and ungripping a selected fuel rod, a work station for securing the nuclear fuel rod assembly to be repaired into a desired location, and a positioner device for laterally positioning the rod handler over a selected rod in the fuel assembly secured within the work station. The rod handler includes a contractable collet for gripping and ungripping a desired fuel rod, and a rod sensor concentrically disposed within the collet for sensing when a rod is in a grippable position. The positioner includes a movable carriage which is slidably mounted onto a frame assembly by means of a pair of rail and bearing mechanisms. The system also includes a microcomputer for controlling the manner in which the positioner positions the rod handler, as well as gripping, lifting, lowering and ungripping motions of the handler itself.

Abstract: A flail tube cutter having an elongated cutting head circumscribed by a generally circular cutting blade, a means of rotating this cutting head, and a flexible shaft for coupling the cutting head to the rotating means is disclosed herein. The circular cutting blade of the cutting head includes a serration for defining two cutting teeth. Additionally, the cutting head includes a top portion located above the cutting blade for increasing the impact force of these cutting teeth against the inside wall of the tube being cut. The flail tube cutter of the invention provides a fast-acting tube cutter having a relatively small diameter which is easily snaked through tubes having local restrictions caused by either dents or internally mounted sleeves.

Abstract: A device for removing plugs from plugged tubes in a steam generator including a frame having a substantially flat plate, with a hollow drill bit mounted thereon and movable generally perpendicularly with respect thereto from a storage position to an operating position. An elongated retaining pin extends through the hollow drill bit and therebeyond having threads on one end thereof for attachment to the plug to be drilled. Actuating means moves the drill bit between the storage position thereof and the operating position thereof, motor means is mounted on the frame for rotating the drill bit. An air-water mixture is introduced near where the drill bit meets the plug to be drilled, the water being present in an amount of about one-half volume percent, and a vacuum is used to collect and remove the air-water mixture and any debris entrained therewith due to drilling the associated plug.