METHOD AND DEVICE FOR DISMOUNTING IRRADIATED ELEMENT OF A NUCLEAR REACTOR, IN PARTICULAR VESSEL OF A PRESSURIZED-WATER REACTOR

The tubular wall (1) of the irradiated component is machined on its upper annular surface, with chips (44) being formed by the use of a metal working machine (30) bearing on this upper surface and moving in rotation about the axis (6) of the wall (1) of the component. The chips (44) formed by the metal working machine (30), e.g., a milling head, which moves in the vertical direction and downwards, are collected and cleared away continuously during the progress of the machining in the axial direction (6) of the wall (1) of the component. The device is fastened to the upper part of the tubular casing (1), arms (7a, 7b) equipped with jacks allowing the device (4) to be flanged to the wall (1) of the component, and bearing devices (12) comprising arms (13) being mounted pivotably about a horizontal axis between a low bearing position and a high withdrawal position (13'). The bearing arms (13) change from their low position to their high position at the moment when the machining tool (31) passes.