Abstract: 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).

Abstract: The device comprises a pole fastened to a handling and lifting apparatus arranged above the pool in which the fuel assembly is placed under water. The pole has at least one lower end part (32), the diameter of which is less than the inside diameter of the blocking sleeve (25). This part (32) is pierced with a central bore (40) and with at least two radial orifices (56), in each of which is located a retention claw (57). A rod (41) sliding in the axial bore (40) makes it possible to control the extraction of the claws. The vertical movement of the pole makes it possible to extract the blocking sleeve (25).

Abstract: The device comprises a pole (31) fastened to a handling and lifting means arranged above the pool in which the fuel assembly is placed underwater. The pole has at least one lower end part (32) or spindle, the diameter of which is less than the inside diameter of the blocking sleeve (25). This part (32) has a spring means (48) for retaining the blocking sleeve in the position engaged on the spindle, and a transversely arranged surface (38) for bearing on part of the sleeve (25), and a means (40) for the vertical movement of the pole (31).

Abstract: The device comprises a pipe for aspiration and delivery of water from a well, a column suspended from a traveling crane located above the well and an aspiration head fixed at the end of the column opposite to the crane. The aspiration head is composed of two hollow walls assembled to one another, between which there is a filtration wall separating the internal volume of the head into a first part having an aspiration opening and a second part connected via a conduit to the aspiration pipe.

Abstract: The positively acting mechanism comprises a jack (2) with a rod (10) connected, at one of its ends, to a member whose actuation or retention it ensures, and, at its other end, to a thrust piece (16), on which a spring (18) comes to bear, in order to actuate or retain the member. An axle (25) parallel to the rod (10) of the jack is rotatably mounted in a housing (14) fixed relative to the body (3) of the jack (2) and has a threaded part (26) in engagement with a nut (34) forming an engagement fork for the thrust piece (16) of the rod (10). The axle (25) has an end part (30) engaging with a tool allowing the axle (25) to be set in rotation remotely. It is thus possible, in the event of failure of the jack, to rotate the axle (25) and displace the rod (10) of the jack (2) in the direction of release of the mechanism.

Abstract: The device comprises a rod (20) on which is mounted a means (22, 24, 25) for the support and displacement of a work tool which is movable in an axial direction of the rod (20) and in two directions perpendicular to this axial direction. The tool comprises tongs consisting of two arms which are articulated together about a spindle fixed on the means (22, 24, 25) for support and displacement in a direction parallel to the axis of the rod (20). The tongs comprise end jaws which are capable of gripping a fuel rod. The gripping of the tongs is controlled remotely and the positioning of these tongs on a fuel rod to be removed is checked by means of a video camera (26).