Abstract: Reactor building comprising internal structures, whose stresses are independent of the deformations of the general floor and of the background effect due to the reference accident pressure, and process for producing the internal structures.This reactor building comprises a confinement enclosure (4), internal structures (14) constituted by a slab (22) peripherally locked against the frustum-shaped member (12) of confinement enclosure (4) and resting on the general floor (8) by a peripheral supporting ring (23), a compressible layer (32) being provided between the general floor (8) and slab (22).Application to the construction of the internal structures of a reactor building.

Abstract: Gas-cooled high temperature reactor asembly, including a safety container, a chamber disposed in the safety container, a reactor vessel disposed in the chamber for receiving a charge of spherical fuel elements at a given location therein, the reactor vessel being formed of blocks of at least one material from the group consisting of carbon and graphite, a steel shell surrounding the reactor vessel, a metallic base plate supporting the reactor vessel, the base plate having openings formed therein for passing cooling gas blown in the chamber into the given location for a fuel element charge, at least one downwardly extended pipeline having a connection to the base plate for discharging heated gases, the connection being detachable by axial motion of the reactor vessel, a removable cover disposed on top of the chamber, and means disposed on the reactor vessel for connecting the reactor vessel to hoisting apparatus.

Abstract: Reactor building comprising a vessel shaft anchored in a slab which is peripherally locked.This reactor building comprises a confinement enclosure (4) within which are positioned internal structures (14) constituted by an internal structure floor (16), a vessel shaft (18), a slab (22) being positioned between the general floor (8) and the internal structure floor (16), the vessel shaft (18) being anchored in the slab which is peripherally locked against the low part of the confinement enclosure skirt (12), a horizontal sliding joint (24) being positioned between slab (22) and internal structure floor (16).Application to the construction of the internal structures of a reactor building.

Abstract: A concrete cell structure for storing irradiated nuclear fuel has air inlets in the roof and a stack for effecting natural draught ventilation. Air flows through the cells in heat exchange with nuclear fuel containers. The concrete cell structure is housed within a steel framed and sheeted weather tight building which provides a large air plenum for the inlet ports and thereby avoids serious pressure variations at the inlets caused by wind loadings.

Abstract: A liquid metal cooled nuclear reactor of the kind wherein a fuel assembly is supported on a diagrid and submerged in a pool of coolant. The diagrid comprises a plenum supported on a load bearing undershell and has an array of resilient spikes upstanding from the upper face of the plenum each for locating a fuel sub-assembly. The load of the fuel assembly is distributed over the upper face plate of the plenum and transmitted to the undershell by an array of strut members.

Abstract: Nuclear power plant with a reactor building, a fuel building, buildings for the ancillary nuclear, electrical and safety equipment, and a building for turbo-electric machines. The group of buildings is in the general shape of a T, with the fuel and ancillary equipment buildings (2) and (3) in line at both sides of the reactor building, and the engine building (6) facing the reactor building (1) and perpendicular to the latter. The vault of the protective enclosure is connected to the foundation of the reactor building and is in the shape of a cylinder with horizontal generatrices. The invention is applicable to light water nuclear power stations.

Abstract: In a method for the controlled removal of hydrogen released into the chambers of a nuclear reactor containment after a break of the primary cooling system, the hydrogen is contacted with an oxygen providing material stored in the containment which causes recombination of the hydrogen to H.sub.2 O in a controlled manner at least until the amount of the gas within the hydrogen chamber is below the ignition limit of a hydrogen oxygen gas mixture.

Abstract: A confinement enclosure, notably for a nuclear reactor, of the type consisting of reinforced, possibly prestressed concrete, comprising in the body of the wall a drainage network consisting of tubular channels provided in the concrete, wherein the tubular channels of the drainage network, which may be grouped in sub-groups, are connected to a system of filters located inside the enclosure.

Abstract: Apparatus for preventing the diversion of plutonium in nuclear fuel reprocessing plants. The apparatus includes various piping arrangements which prevent plutonium in a liquid state from being drawn out of a nuclear fuel reprocessing cell through conduits which are normally accessible to the operators of the facility.

Abstract: The system according to the invention comprises a first room which accommodates a reactor plant and an active-type sprinkler means to condense steam released by the ebullient coolant after an accident. A loss of coolant may occur at any point of the reactor plant; that notwithstanding, the rising pressure in said first room drives the air out of that room through holes provided in the walls of the room in immediate proximity to the floor and spaced at a maximum distance from one another over the perimeter of the walls. The air is forced into an intermediate chamber wherefrom it is directed to a second room through channels and a basin-type condenser arranged in a second room. The length of the channels is selected so as to form a water seal to prevent the backflow of air driven from the first room to the second room and thus produce rarefaction in the first room.

Abstract: A core energy plant with closed working gas circuit, in which within an or safety container there are arranged a reactor core of pre-stressed concrete for heating the working gas, a working gas driven turbo-set with generator, and other components of the working gas circuit such as heat exchanger and gas storage means. The reactor core is separated from the turbo-set and other components and is arranged in a separate reactor chamber with walls of pre-stressed concrete, while the other components are respectively arranged in separate chambers, within an inner concrete container which has chambers for receiving the turbo-set with generator and the remaining components of the working gas circuit and which has its outer wall arranged adjacent the vertical inner wall of the outer safety container there is provided a recess for a pre-stressed concrete container for receiving the reactor core.

Abstract: The present invention relates to an improved attachment assembly for clamping a nuclear reactor foot ring into engagement with a surrounding support wall while allowing for thermal expansion of the foot ring.

Abstract: A device having a tubular body of an increased diameter closed at its bottom and connected at its top to the lower end of a vent pipe in such a state that the tubular body is immersed in a water pool. The tubular body is formed in its side wall with a multitude of openings for venting steam therethrough to the water pool to condense the same.

Abstract: A structure for an underwater nuclear power generating plant comprising a triangular platform formed of tubular leg and truss members upon which are attached one or more large spherical pressure vessels and one or more small cylindrical auxiliary pressure vessels.

Abstract: Nuclear reactor installation having a concrete cell disposed beneath the earth of a hill for enclosing activity-carrying components includes at least one additional concrete cell disposed in the earth separated from the first-mentioned concrete cell, the additional concrete cell having at most one-fortieth the volume of the first-mentioned concrete cell and being at least predominantly of shell-like construction, and including equipment of use for the nuclear reactor installation received in the additional concrete cell.

Abstract: A nuclear reactor with a cylindrical reactor pressure vessel disposed in a reactor cavity formed in a concrete biological shield surrounding and spaced from the pressure vessel includes means for suspending the reactor pressure vessel from the concrete biological shield, the suspending means being a plurality of tension bolts distributed about the periphery of the cylindrical reactor pressure vessel and secured to a corresponding plurality of brackets attached to the cylindrical reactor pressure vessel, the tension bolts extending from the brackets at an inclined angle through the biological shield.