How to repair the bottom head penetration of a reactor vessel

摘要

A method for repairing a nuclear reactor tank base penetration, comprising a tube (10) fixed on the internal tank wall (1a) by a solder strand (11) with formation of a groove, involves forming a model of the tube; fixing two half-inserts (30A, 30B) in the model groove; forming a solder strand (35) in the model groove; carrying out dimensional control; and automatically fixing the half-inserts and forming the modelled solder strand directly in the groove for repair under remote control. A method for repairing a tank base penetration in a nuclear reactor, consisting of a tube (10) fixed to the tank internal wall (1a) by an internal solder strand (11), opening outside the tank and forming a groove with the outer tank wall, is carried out after detecting a boron deposit on the tube and tank base exterior as an indication of failure of the solder strand. The method involves: (A) preparing a model of the penetration, comprising part of the tank base and the tube, with a groove as above, and placing the model on site in a non-irradiated zone; (B) fixing in the groove of the model two half-inserts (30A, 30B), each corresponding to a half-profile of the groove; (C) automatically forming a solder strand (35) in the groove of the model under remote control; carrying out dimensional control and validation on the obtained strand; (D) removing boron (preferably by brushing) from the tube of the penetration to be repaired; and (E) fixing the two half-inserts and forming the solder strand (35) directly in the groove of the penetration to be repaired, automatically and under remote control.