Abstract: In order to ensure the recovery and confinement of the core of a nuclear reactor, such as a pressurized water reactor, in the case of a serious accident leading to its melting or meltdown, it is proposed that below the reactor vessel (16) be placed a receptacle (20) able to evacuate the water accumulated below the vessel (16) in the initial phase of the accident and then collect the molten core debris. The water automatically flows through overflow and siphon devices (46, 50) into a cooling space (40) located below the receptacle. If the meltdown of the core (18) has been detected, the water contained in tanks (56) flows by gravity into the space (40), so as to entirely immerse the containers (26) placed in said space. The molten core traversing the bottom of the vessel (16) flows into the receptacle (20) and then into containers (26) via meltable plugs (32) and a natural convection flow is established between the tanks (56) and the space (40) in order to ensure cooling.

Abstract: Apparatus is disclosed for the dry storage of heat-emitting radioactive waste materials. The latter are stored in tubes placed within a room having at least one cold air inlet and a hot air outlet. The distance between adjacent tubes and the distance between a tube and a wall of the room is such that a conically-shaped hot air boundary layer formed by natural convection around a tube is in contact neither with the boundary layer of another tube, nor with the wall of the room.

Abstract: Apparatus for transmitting a beam of energy includes a first arm formed by a hollow tube, which is rotatable about its own axis, a second arm formed by two half-arms, arranged symmetrically with respect to the axis of the first tube and movable with respect thereto by means of an articulation, and a third arm formed by a hollow tube, articulated to the half-arms by two intermediate parts.

Abstract: A radiation-tight coupling arrangement for coupling a machining laser to a hot cell containing radioactive material, comprising a cell flange integrally formed on the confinement wall which defines a cell opening, a cell door formed to interlock tightly with the cell flange, thereby closing the cell opening, an elongated container movably arranged in the sleeve and having a container flange defining a container opening and connected by a sealing bellows, a container door formed to interlock tightly with the container flange and to interlock with the cell door when the container flange interlocks with the cell flange, and a machining line translationally arranged in the container. When the container is in a retracted position, a radiation blocking drum intervenes between the cell opening and the container opening. The radiation blocking drum is rotated to allow the container to translate toward the cell.