Framatome Anp Gmbh

Pascal Latreille

Jean-Michel Channussot

Christophe Parize

Marc Gely

Marking of the cuts which have to be made, cutting of the section at two ends, removal of the section which has to be replaced, bevelling of the joint ends of the parts remaining after the section has been cut out from the pipe, adjustment of a new or replacement section for length and bevelling of its joining ends and positioning and narrow bevel welding of the ends joining the replacement section to the ends of the remaining parts of the pipe are performed outside the pipe. Within the pipe operations of machining and inspecting an internal part of the joining ends welded together are performed by remote control in a programmed way by introducing and positioning means for working within the pipe from a component of the primary circuit. The procedure is in particular used to effect the replacement of a section of a cold leg of the primary circuit using means for carrying out work comprising a robot arm secured to a supporting chassis borne by a carriage which moves the means for carrying out work within the cold leg inserted into the cold leg through the volute of the primary pump of the nuclear reactor.

Procedure and means for replacing and procedure for repairing a section of a pipe in the primary circuit of a nuclear reactor

In a nuclear reactor, cooled by pressurized water, an apparatus is employed for replacing a section of a primary circuit primary pipe that interconnects first and second components of a primary circuit. The apparatus cuts out and removes a section of the primary pipe. Supports are provided for the end parts of a new replacement section in a position held by the removed pipe. The apparatus bevel welds the end parts of the new replacement section of the primary pipe to confronting corresponding ends of the remaining primary pipe. Means are provided to work within the pipe along the entire length of the interior surface of the primary pipe and is introduced through one of first and second components of the primary circuit to a location within the welded replacement pipe section.

The maintenance device comprises a robot () for carrying out maintenance work in a remote-controlled or programmed way in the maintenance region. The robot () comprises a supporting part () connected to a clamping support () secured to a means () of transporting the maintenance device () between an introductory region and the maintenance region. The clamping support () comprises clamping shoes () which can be moved in roughly parallel and opposite directions so as to clamp the maintenance device () in the maintenance region. The transport means () may be constructed in the form of a carriage comprising two motorized wheelsets. The device and the method of the invention make it possible in particular to carry out machining or inspection work inside primary pipes of a pressurized water nuclear reactor.

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Saint Germain du Plain, France

Pascal Latreille