Abstract: In a nuclear reactor building of a steel plate concrete structure that houses a pressure containment vessel formed with a plurality of penetration ports penetrating the pressure containment vessel on the periphery thereof and includes a biological shielding wall disposed outside the pressure containment vessel. The pressure containment vessel is vertically divided into a plurality of blocks so that each of the blocks has one or more pressure containment vessel penetration ports arranged on a same horizontal plane, and the reactor building including the biological shielding wall is divided into a plurality of modules by the horizontal plane.

Abstract: A containment of a nuclear power plant has a pressure chamber, a condensation chamber, and a substantially vertically running condensation tube. The upper end of the tube is connected to the pressure chamber and the lower end of the tube is immersed in a cooling liquid in the condensation chamber. The lower end of the condensation tube has an elbow and an outlet nozzle. The elbow has an elbow angle which is such that the lower end of the elbow is immersed obliquely in the cooling liquid in the condensation chamber, and the outlet nozzle has an outlet opening which is substantially shielded with respect to the base of the condensation chamber. This renders it possible to significantly reduce the pressure loads on the base and the walls of the condensation chamber in the event of an emergency.

Abstract: Passive emergency cooling in response to a loss of coolant accident (LOCA) in a PWR, having an integral reactor pressure vessel incorporating the steam generators and housed in a small high pressure containment vessel, is provided by circulating cooling water through the steam generators and heat exchangers in an external tank to cool the reactor vessel at a rate sufficient to lower the pressure in the reactor vessel below that in containment to reverse mass flow out of the reactor vessel and keep the reactor core covered without the addition of makeup water. Suppression tanks inside the small high pressure containment structure limit peak blowdown pressure in containment and provide flood-up water and gravity fed makeup water to cool the core. Diverse cooling is provided by natural circulation of air, and if needed, water, over the spherical containment structure.

Abstract: The present invention, in one form, is a natural circulation reactor having, in one embodiment, a layer of high aluminate cement concrete disposed between an uninsulated steel liner and a prestressed concrete reactor vessel. The prestressed concrete reactor vessel includes a concrete shell having a cavity therein. The steel liner is positioned in the cavity and spaced from the concrete shell so that an insulating chamber is formed between the steel liner and the concrete shell. The insulating chamber is filled with high aluminate cement concrete which is configured to substantially insulate the concrete shell from the steel liner and to transfer loads such as pressure from the liner to the concrete shell.

Abstract: A nuclear steam supply containment system employing prefabricated component supports that are surrounded by steel concrete forms and anchored to the floor liner of a nuclear containment. The prefabricated component supports extend through the concrete forms and a reinforce concrete slab cap to a support elevation for the component. A second inner steel concrete form can be employed to form an annular concrete channel through which the supports extend. The center of the inner form can be filled with a sand-like substance, radiation absorber material or concrete grout.

Abstract: A liquid metal nuclear reactor is described. The reactor includes a concrete reactor silo, and at least one primary vessel located in the reactor silo and coupled to a reactor shield deck. Each primary vessel is substantially surrounded by a containment vessel in a spaced apart relationship. The reactor also includes a heat removal system which includes a guard vessel substantially surrounding each containment vessel in a spaced apart relationship, at least one inlet conduit in fluid communication with the ambient atmosphere outside the nuclear reactor, and at least one outlet conduit in fluid communication with the ambient atmosphere outside the nuclear reactor. A fluid flow heat transferring flowpath is formed by the inlet conduits, the space intermediate the guard vessel of each primary vessel and the containment vessel of each primary vessel and the outlet conduits.

Abstract: A reinforced concrete containment vessel in a nuclear reactor includes a cylindrical shell having a side wall. The side wall includes an opening and a plurality of reinforcing bars, at least one of which is interrupted at the side wall opening. A reinforcing plate having an opening is located in the cylindrical shell so that the reinforcing plate opening is aligned with the side wall opening and the interrupted reinforcing bars are connected to the reinforcing plate. Reinforcing bar terminators connect the reinforcing bars to the reinforcing plate.

Abstract: A joint for interfacing a steel head closure and a steel-lined prestressed concrete reactor vessel (PCRV). The steel head closure is bolted to a thick steel annular plate and a thermal barrier is arranged in a volume bounded by the head ring, the liner and the concrete of the PCRV wall. The thermal barrier is made of zirconia sand or other material having a low thermal conductivity, a high bulk modulus equal to that of concrete, and a low shear modulus. Differential thermal expansion of the vessel head closure and PCRV is accommodated by a flexible connection of the PCRV liner to the inner periphery of the head ring. In the alternative, the steel head closure is interfaced to the top of the PCRV via a sliding joint or a thermal stress relief ring. In accordance with a further alternative, thermal stresses in the steel vessel head closure are mitigated by reducing the temperature of the head closure by installing thermal insulation on all internal surfaces thereof.

Abstract: A wall, particularly a wall of a containment for a nuclear plant, a pool or a cavern, includes a bearing wall. A sealing element is disposed on at least one surface of the bearing wall and covers the bearing wall. A protective wall covers the sealing element. The protective wall is frictionally connected to the bearing wall. The protective wall may be formed of a plurality of parts. The frictional connection may be made by anchors as well as by prestressing or by adhesive bonding.

Abstract: A method of constructing the top slab of a nuclear reactor container in which a flange for mounting the top head of the container is prepared separately from the sleeve of the container. When the outside diameter of the flange is greater than the inside diameter of a doughnut-shaped steel; reinforcement structure assembled on the container, the steel reinforcement structure is situated in place and then the flange is welded to the sleeve, thus shortening the construction period. Disclosed also is a nuclear reactor container constructed by this method.

Abstract: The present invention presents a novel apparatus and a method of demolishing a biological shield wall of a nuclear reactor using a concrete cutter device working on a wire saw, said apparatus comprising a concrete cutter device consisting of a driving part for a wire saw and a concrete cutting part attached on the engaging receiver of the driving part, a core boring machine to be attached interchangeably on the receiver in the place of the cutting part and a carrier truck to carry the wire saw driving part of said cutter device, further the concrete cutting part having a pair of vertical rods supported on a table movable vertically and adjustable in a distance of the rods and, at the bottom end of the rods, supporting pulleys and guide rollers for disposing the wire saw are provided.

Abstract: This reservoir is provided with a fluidtight covering of metal sheets (6) welded together by their edges and supported by beams (2) each comprising two section elements (16, 17), and three longitudinal channels. In cross-section, the first and second section elements each have the shape of a U, the second section element being substantially narrower than the first element and being fixed by the edge of its branches (18) to the bottom (19) of the first section element so as to define an inspection channel (20) having a closed cross-section, and two draining channels (21) having an open cross-section. The surface of the bottom of the second section element (17) which faces toward the exterior of the beam, is contained in the same plane as the edges (11) of the branches (22) of the first section element (16) so as to form the bearing surface (14) for two sheets (6) in the region of their weld head (15) which interconnects them.

Abstract: The invention relates to a nuclear power station for a gas cooled high temperature pebble bed nuclear reactor. The nuclear power station is characterized by a combination of features, whereby the system inherent properties of a high temperature reactor are utilized to make possible the economical operation of a nuclear power station of medium capacity (300-600 MW.sub.el) while maintaining a high standard of safety. The characteristics comprise a reactor protection building equipped with pressure relief means in combination with filters, several auxiliary cooling systems separate from the operating cooling systems for the removal of decay heat in the case of accidents, and the utilization of a liner cooling system for the prestressed concrete reactor pressure vessel to assure the removal of the decay heat in case of a failure of the auxiliary cooling systems.

Abstract: A cost-effective configuration of a metal liner for a reinforced concrete pressure vessel is disclosed wherein only stud shear connectors and cooling tubes of the liner cooling system are used to anchor the liner and the passages provided in the liner and the wall of the vessel. In the areas of the introduction of forces, stud connectors of different stud rigidities are used. In the anchoring of loads which is again effected by stud connectors only, further transmission is obtained by means of reinforcing rods.

Abstract: A method and an apparatus for avoiding or reducing the interactions and their consequences from contact of hot liquid metals with concrete. At least for the region of the concrete structure near the surfaces which may come into contact with the hot liquid metal, there is employed a concrete containing aluminum oxide, magnesium oxide, zirconium oxide, or a mixture thereof, in a proportion of 70% by weight to 96.5% by weight.

Abstract: Slab for closing a fast neutron nuclear reactor, comprising a first central annular part (10) the diameter of which is substantially equal to the diameter of the reactor vessel (5) and a second peripheral annular part (11) connected to the first part (10) by its outer shell (14). Both parts of the slab are made in the form of steel caissons enclosing concrete. The central part (10) is strengthened by two frusto-conical shells (20, 21). The peripheral part (11) is strengthened by flat axial webs. The inner shell coincides with the outer shell (14) of the central part. The invention applies in particular to fast neutron nuclear reactors cooled with liquid sodium, of an integrated type.

Abstract: A lined tank comprises a plurality of lining plates attached to the inside surface of the tank, concrete shutterings disposed inside of the lining plates and embedded in concrete, shaped steel members embedded in the concrete to which the shutterings are attached, backing plates attached to the embedded shaped steel members at the attached portions of the lining plates, leakage detecting channels which are defined by the above elements, and means connected to said leakage detecting channels and adapted to detect the leakage of the lined tank.