Device for the underwater machining of a spacer-grid of a fuel assembly for a nuclear reactor

摘要

The device comprises a platform (13) fixed in a horizontal position on a support structure (3) for the fuel assembly (4) placed under water in a pool (1). The platform (13) includes a table (14) for shifting a carriage (35) in two crossed directions in a horizontal plane and an arrangement (27) for clamping the fuel assembly so as to immobilize it in the machining position. The fuel assembly (4) is placed in the machining position by a hoisting device (6). A table (15) mounted on the table (14) for movement in one of said crossed directions in the horizontal plane is returned elastically (40) in the direction toward the assembly (4). A frame (16) is fixed on the table (15) and permits shifting a tool-carrying carriage (49) in a direction defined by the frame (16). A motorized grinding unit (17) is fixed on the tool-carrying carriage. The device may be used in particular for cutting or levelling the surface of a spacer-grid (8) of a used fuel assembly (4).