Patent Number: 
Section: claims

1. An incore piping section maintenance system of a reactor, comprising: a maintenance system main body having a portion to be inserted into a pipe of an incore piping section located in a reactor pressure vessel;  a main body supporting mechanism for detachably fixing the maintenance system main body to an inner surface of the pipe;  a turning arm mounted to another portion of the maintenance system main body and disposed outside the pipe and the maintenance system main body;  a turning mechanism for turning and driving the turning arm;  an axial moving mechanism disposed to the turning arm and slidable in a direction substantially parallel to a central axis of the pipe;  a laser generator for generating a laser beam;  a laser de-sensitization treatment mechanism supported by the axial moving mechanism and for irradiating the laser beam to an outer surface of the pipe; and  an optical transmission mechanism for guiding the laser beam outputted from the laser generator to the laser de-sensitization mechanism. 2. The incore piping section maintenance system of a reactor according to  claim 1 , wherein the incore piping section maintenance system includes at least three main body supporting mechanisms and each of said main body supporting mechanisms is constructed in combination with a link mechanism including a guide member and a cylinder assembly for driving the guide member of the link mechanism in and out of the maintenance system main body. claim 1