METHOD AND APPARATUS FOR REMOVING PRESSURE TUBES FROM NUCLEAR REACTORS

摘要

An apparatus and method for removing a pressure tube from a nuclear reactor end fitting. A series of grooves are milled in the inside surface of the pressure tube in the area of the roll fitting by means of an elongated milling tool inserted in the pressure tube. The milling tool has a rotary cutter bit that can be controlled for longitudinal and rotational position and depth of cut from the proximal end of the tool. Once the grooves are milled, the milling tool is withdrawn and replaced with an elongated collapsing tool. The collapsing tool has a pair of jaws that engage the milled grooves and draw the wall of the pressure tube inward thereby releasing it from the end fitting. The use of the present invention avoids the requirement to remove both end fittings to replace a pressure tube.