Device and method for blocking an orifice of a tube wrapper of a steam generator of a nuclear reactor with pressurised water

摘要

The device (20) has internal and external upper semi-flanges (27, 28) displaceable by a movable shaft (21) in rotation of 180 degree between a lower position with respect to internal and external lower semi-flanges (25, 26) to introduce the shaft in an external orifice of a cylindrical shaped pressure boundary of an steam generator, and an internal orifice of an tube wrapper of the generator, and an upper position opposed to the lower semi-flanges. A tightening unit has a nut (22) to tighten the semi-flanges on circumferences on sides of the internal orifice for closing the internal orifice. Independent claims are also included for the following: (1) a method for closing an internal orifice of an tube wrapper of an steam generator of an pressurized water nuclear reactor using a internal orifice closing device (2) a tool for fixing and removing a internal orifice closing device.