Group of facilities for unloading and reloading a nuclear reactor

This invention concerns a group of facilities for unloading and reloading a water cooled nuclear reactor, this group of facilities being particularly adapted for use with a nuclear reactor on board ship. These facilities include a pressure vessel inside which a core formed of several fuel assemblies characteristically comprises a removable ring intended to serve as a pond, facilities for coupling the bottom edge of this ring to the top edge of the vessel, means for sealing the joining of the ring to the vessel and gear for hoisting and transferring the fuel assemblies, such facilities forming an integral part of this ring