Abstract: A device for optimum positioning of at least one extension piece (10) on at least one threaded connection element (1) for fastening a component to an appliance, each extension piece being screwed onto one connection piece, and the device comprising a module for supporting and tensioning the threaded connection elements (1) by means of the extension pieces (10). The module is centered on the threaded connection elements (1) and supported relative to the component, and the extension pieces are slid in a horizontal plane relative to the axis of the threaded connection element (1).

Abstract: The adaptor for screwing or unscrewing a thread connecting element (2), comprising a body (10) joined, at its upper end, to a unit (1) for driving the body (10) in rotational and translational movement comprises an arrangement for centering the body (10) on the threaded connecting element (2), an interconnection between the body (10) and the threaded connecting element (2) in terms of rotational and translational movement, means for temporarily interconnecting in terms of rotational movement the means for connecting in terms of translational movement and the body (10), and a hydraulic distributor (18) mounted on the body (10).

Abstract: An apparatus for handling a machine for the simultaneous tensioning of screwed connecting elements (3) such as bolts or pins intended, for example, for the fastening of the cover (1) of a vessel (2). The apparatus comprises a tensioning module (20) for the connecting elements (3), an arrangement (10, 11, 12) for moving the tensioning module (20) in a horizontal plane, and an arrangement (15, 22, 24) for moving the tensioning module (20) along the vertical axis of the connecting elements (3).

Abstract: Apparatus for screwing on and off a clamp nut (5) and an extension piece (13) facing the clamp nut. The extension piece (13) of each of plurality of connection members (2) cooperates with a ring (1) for simultaneously tensioning the connection members. The apparatus includes a carriage (20) for guiding and displacing the apparatus around the ring (1) tensioning the connection member (2), a disengageable system (30) for displacing and rotationally driving the extension piece (13) which is to be screwed on or off, and a disengageable system (40) for rotationally driving the clamp nut (5) which is to be screwed on or off. These systems are supported by the carriage (20) and are displaceable along an axis parallel to the axis of the connection member (2) and at a speed identical to that of the nut (5) or of the extension piece (13) in the course of its screwing or unscrewing.

Abstract: The device for screwing and unscrewing a nut (30-32) on a coupling member (2), comprising a framework (14) pivoting around a shaft (15) parallel to the coupling member (2), a gear train (17, 19, 22, 26) for driving in rotation the nut (30-32) to be screwed or unscrewed, and a drive assembly itself moving in rotation along an axis parallel to the axis of the coupling member (2) and at a speed identical with that of the nut in motion while it is being screwed or unscrewed.

Abstract: The adaptor comprises a nut (2) screwed onto the end of the connection element (1) and interacting with a two-way connector (4) adapted to ensure the connection between a screwing or unscrewing member and the connection element (1), an arrangement between the nut (2) and the connector (4) allowing the connector (4) to rotate in only one direction, and a spring insert (44) for the elastic support of the connector (4) on the end of the connection element (1).

Abstract: Device for checking clearance between the periphery of the upper core plate and the inner surface of the core enclosure of a pressurized water nuclear reactor comprising a vertical supporting structure (7) resting on the upper plate (3), a plurality of articulated assemblies (10), each carrying a calibrated feeler blade of a specified thickness, a pivoting assembly associated with each of the articulated assemblies, for moving the blades (9) in a substantially vertical direction towards the gap between the plate (3) and the enclosure (1, 2), or in the opposite direction, as well as a video camera (14) in the vicinity of the blades (9). The device enables the checking to be carried out under water and by remote control.

Abstract: Device for checking the vertical alignment of the upper and lower internal equipment of a pressurized water nuclear reactor comprising a vertical tubular body (14) onto which are fixed a flange (15) for centering the upper internal equipment on the upper plate (2), a flange (16) for centering on the upper core plate (3) and a lower end member (17) which enables the device (1) to be centered on the lower core plate (4). A metal wire (24) is aligned along the axis of the tubular body (14), its lower part being fixed to the end member (17) and its upper part to a fitting (20) which can move in two horizontal directions at 90.degree.. Electrodes are arranged in the flange (16) around the wire (24), to detect, by virtue of an electrical monitoring circuit (90), contact between the wire (24) and the electrodes when the upper part of the wire is moved by the fitting (20).

Abstract: With the reactor vessel (1) open and filled with water, and the core assemblies removed, means for measuring alignment (50) and means for measuring clearances (56, 58, 59) are mounted on the upper internal equipment (13). The upper equipment (13) is introduced into the vessel and is deposited on the lower equipment (3). Measurements of alignment are carried out and, if appropriate, the alignment is corrected by moving the upper internal equipment on the lower equipment (8). The clearances of the upper core plate are measured and, if appropriate, the upper internal equipment (13) is moved as a function of these measurements. The clearances around the centering and alignment pins are measured and adapters are machined and then fixed to the upper internal equipment (13) to reduce the clearances around the pins to a low, predetermined value. The invention also relates to the device for measuring and adapting the position of the internal equipment.

Abstract: Device for measuring clearance around a pin for centering the upper internal equipment of a pressurized water nuclear reactor comprising a carrier (b) fixed integrally to a pedestal (7) which makes it possible to fix on the upper plate of the reactor core (1) two travellers (15) which are parallel to the plate (1), two slides mounted to move on the travellers, resilient means (22) for returning the slides and a marking assembly carried by the carrier. Each slide comprises a sensing finger (30) projecting downwards relative to the bearing face of the pedestal (7) and a planar marking plate (31). The marking assembly comprises two styli (33), each directed towards a marking plate (31). A control system (34) makes it possible to compress springs (36) whose force is applied to the styli (33). The clearance measurement can be carried out from a distance and under water.