Abstract: An apparatus and method for loosening a mechanical plug in a tube. A cartridge having a nose portion, central portion formed from a material that produces an exothermic reaction when ignited, and a base is inserted into the plug to be loosened and removed. An insulated wire extends through the base into the central portion and is connected to a resistive noninsulated wire positioned in the central portion. Sending an electrical current through the wiring causes the noninsulated wire to heat up rapidly. The rapid heat buildup initiates an exothermic reaction in the central portion. The heat generated causes stress conditions in the plug that exceed plug yield and results in a stress relief condition in the plug where the diameter of the plug is reduced. This loosens the plug in the tube and reduces pulling forces needed to remove the plug from the tube.

Abstract: A method of sealing leaking steam generator tubes without substantially restricting the fluid flow area by explosively welding a cylindrical sleeve over the degraded area of the tube. The sleeve has a wall thickness of approximately 0.010 to 0.040 inches and a length of about 1.5 to 4.0 inches, the weld occurs over the entire length of the sleeve.

Abstract: A system for inspecting the relatively long, thin-walled, small-bore tubes of a heat exchanger provided with support plates for holding the tubes in predetermined positions, comprising a composite scanner having a plurality of flexure springs contacting the interior surface of a tube for detecting and profiling tube abnormalities as the scanner traverses the tube and an eddy current sensor incorporated in the scanner for generating a unique signal as the scanner passes a contiguous support plate to assist in the accurate location of tube abnormalities.