Abstract: Apparatus for loading and unloading fuel assemblies, for fast neutron nuclear reactors, and in particular for groups of fast neutron nuclear reactors cooled by liquid sodium located on one and the same site. The apparatus is removable as a unit and comprises a lock chamber (25) in the form of a removable and transportable vessel. The vessel (25) contains a pivoting ramp (35) allowing transfer of assemblies between the primary ramp (28) and the secondary ramp (29) of the nuclear reactor. Apertures (26) and (27) corresponding to the ramps (28) and (29) respectively are provided in the wall of the vessel (25) and connecting and isolating apparatuses (30) and (31) allow the lock chamber to be placed in communication with the ramps of the reactor, or conversely to be separated from the reactor and isolated.

Abstract: A dismountable and movable device for the transfer of fuel assemblies for a breeder nuclear reactor, comprising a platform (11) mounted for rotation on a support (12) resting on the structure of the reactor. The platform is provided with apertures (19, 20) and carries a hopper (23) which can contain a fuel assembly (5) in vertical position, at the level of one of the apertures (19). The apertures can be brought into correspondence with vertical shafts (14, 15) permitting access to storage (5a) and evacuation (5b) positions for the assemblies (5). The hopper (23) contains a winch (37) for the vertical displacement of the assemblies in the hopper and the shafts when they are in correspondence. The shafts and the platform comprise complementary connecting and sealing devices to assure the connection between the hopper and the shafts. The device is particularly useful for reactors grouped on one and the same site where transport of the assemblies is effected by modules displaced on the site.

Abstract: The device is constituted by a seal-bearing ring 21 disposed about the flange 2 of the component 5 and resting on the plate 1 of the reactor, having a first set of annular seals 26,27 ensuring sealing between the inner side surface of the seal-bearing ring 21 and the outer side surface of the flange 2 of the component 5 and a second set of annular seals 23,24 ensuring sealing between the base surface of the seal-bearing ring 21 and the plate 1 of the primary vessel. The device also includes a means 32-34 for applying a vertical force downwards on the seal bearing ring 21 and a means 16,18 of injecting an isolating gas between the flange 2 of the component 5 and the plate 1 of the primary vessel on which the component 5 rests. The device is especially useful for sealed mounting of components within vessels of fast neutron nuclear reactors.

Abstract: Two guide ramps for the transfer of fuel assemblies in sliding motion between the reactor core and an external storage container are surmounted by a lock-chamber in which two pivotally suspended rectilinear rail sections carried by a revolving unit form guide ramp extensions. Each rail section has a lever extension in cooperating relation with a rocking system for displaying the rail section in swinging motion from an inclined position in the line of extenson of one of the guide ramps to the vertical position and conversely.