Method and device for fabrication of nuclear fuel assembly grids.

摘要

The process can be employed for manufacturing a grid intended for a pressurised water reactor fuel assembly. The grid (1) whose constituent parts are to be integrally fastened is positioned into a frame for forming and mechanical support, which has passages for access to the points to be welded on the two large faces and on the sides of the grid; the frame containing the grid is grasped with the aid of a device (27, 28) for orienting around an axis, placed in a sealed chamber occupied by an inert gas atmosphere; the welds are produced on one face at a time with the aid of a laser beam at right angles to the axis of orientation of the device, supplied by a laser source placed outside the chamber and entering the latter through a transparent porthole, and the operation is then repeated on the other faces. During the welding on one face of the grid the laser beam is moved in two directions at right angles to each other and to the direction of the beam, while the frame is kept stationary in the chamber in an inert gas atmosphere.