REMOVAL OF PORTIONS OF TUBES FROM STEAM GENERATOR OF NUCLEAR REACTOR

摘要

32 Apparatus and method for removing and cutting tubes which have become damaged in a nuclear reactor. The apparatus for accomplishing this object includes a base secured to the header of the heat exchanger by expanded mandrel mechanisms. A carriage is suspended from the base on screws which are driven by a motor to move the carriage away from and towards the base. An OD gripper assembly is suspended from the carriage and is movable by rods away from and towards the carriage. An ID gripper assembly extends through the OD gripper assembly. The gripper of the ID assembly is actuable to engage the internal surface of the tube portion. With its gripper so engaged, the ID assembly is engaged by the gripper of the OD assembly and the engaged tube portion is pulled out of the header by the OD assembly. The ID gripper is then disengaged and the OD gripper is engaged with the tube portion in the same was that it engages the ID assembly and the tube portion is pulled out further. A tube cutter having an abrasive wheel then cuts lengths of the tube at an angle so that for examination and testing the tube lengths can be matched and oriented with respect to each other and the defect evaluates.