초록 ▼

A method and a device for manufacturing a grid for use in a nuclear reactor fuel assembly. A grid whose component parts are to be mutually welded is placed in a holding frame having passages for access to points to be welded on two major faces and on the sides. The frame containing the grid is gripp

A method and a device for manufacturing a grid for use in a nuclear reactor fuel assembly. A grid whose component parts are to be mutually welded is placed in a holding frame having passages for access to points to be welded on two major faces and on the sides. The frame containing the grid is gripped with a device in a chamber where an inert gas atmosphere is generated. Welding is carried out on one face of the grid at a time using a laser beam penetrating from outside the chamber and the welding operations are repeated on the other faces. During welding on one face, the laser beam is moved in two mutually orthogonal directions while the frame is held stationary. The apparatus may include two chambers each with a gripping device, one for welding the two major faces and the other for welding the sides.

대표청구항 ▼

A method for manufacturing a grid for a nuclear fuel assembly, said grid having two sets each consisting of mutually parallel inner plates, the plates of one set being at an angle with the plates of the other set, and a belt welded to end portions of said inner plates and forming side faces of said

A method for manufacturing a grid for a nuclear fuel assembly, said grid having two sets each consisting of mutually parallel inner plates, the plates of one set being at an angle with the plates of the other set, and a belt welded to end portions of said inner plates and forming side faces of said grid, comprising the steps of: placing said inner plates and said belt of a grid in assembled condition in a holding frame having passages for access to points to be welded on two major faces and on the side faces of the grid; gripping the holding frame containing the grid with a first device placed in a first closable chamber having a transparent window and rotatable about an axis parallel to said side faces; closing said chamber and creating an inert gas atmosphere therein; executing all welds on one face of the grid parallel to said axis using a laser beam orthogonal to said axis of rotation and originating from a laser generator placed outside the chamber and delivering a beam which penetrates into the chamber through said transparent window, said laser beam being moved along two directions orthogonal to each other and to the direction of said beam while the frame is held stationary in the chamber for executing said welds on said one face; repeating the welding operations on at least another of said faces of the grid which are parallel to the axis after angularly repositioning the device for exposing said another of said faces; removing the frame and grid from said first chamber and gripping said frame with a second device placed in a second closable chamber having a transparent window and rotatable about a axis parallel to at least two faces of said grid other than said four of said major faces and side faces; creating an inert gas atmosphere in said second chamber; executing all welds on one face of the grid parallel to the axis of said second device using a laser beam orthogonal to said axis of said second device and originating from said laser generator placed outside the chamber and delivering a beam which penetrates into the chamber through said transparent window, said laser beam being moved along two directions orthogonal to each other and to the direction of said beam while the frame is held stationary in the chamber for executing said welds on said one face; and repeating the welding operations on other of said faces until all welds have been completed.