METHOD AND APPARATUS FOR DRILLING ELECTRON DISCHARGE OF A CAP OF A STEAM GENERATOR TUBE OF A PRESSURE WATER NUCLEAR POWER PLANT

摘要

The method involves powering electrons discharging drilling electrode (22) by electric current. The electrons discharging drilling electrode is displaced in a tube (5) for placing a free end at a proximity of an interior base (12) of a cap (10). The electrons discharging drilling electrode is lead through the interior base. A to and fro movement of the electrode is carried out for drilling the base of the cap by a disintegration arc created between the free end and the base. The drilling of the base is verified. An independent claim is also included for a device for electrons discharging drilling of a cap of a tube of a steam generator of a pressurized nuclear power plant, comprising fixation units that are formed by an expandable sleeve made of a stainless alloy.