Device for positioning and axial alignment of a fuel assembly and method and apparatus for reconstituting a positioning element

The device for positioning a fuel assembly (10) has a respective face of the core support plate (19) and the upper core plate (9) facing a nozzle (15, 14) of the fuel assembly (10) at least two positioning pins (16, 22) projecting to be engaged in openings of the bottom nozzle (15) or headpiece (14). Each of the positioning pins (16, 22) is fixed in a blind opening (24) having a threaded bore and a supporting surface perpendicular to the axis of the blind opening (24) and comprises a collar intended to come into contact with the support surface when screwing the positioning pin (16, 22) in the threaded bore. A pin is used to lock the locating pin to make its removal. The invention also relates to a method and device for replacing damaged positioning pins on the core support plate (19) or the upper core piaque (9)