An integral-type liquid metal-cooled nuclear reactor comprises a reactor vessel (9) closed by a head (1) and having a lower plenum (16) formed by a separating structure that is attached to the reactor head (1), a core, at least one circulating pump (21) of a primary loop, said circulating pump having a shell (2) connected to the header (1), at least one heat exchanger mounted in a shell (20) connected to the header (1), and a plug (25), wherein the separating structure is configured in the form of an annular element (11) which is attached to the reactor vessel (9) and has, inserted into a guide shell thereof, an end shell (3) connected to the reactor head (1), in-vessel devices (8) are connected to one another and are attached to the peripheral part of the reactor header (1), and the lower end of the shell (20) of the heat exchanger is disposed above the annular element (11), and the lower end of the shell (2) of the circulating pump (21) passes through an opening in the annular element (11) and into the lower plenum (16). The technical result is an increase in operating safety and reliability.
G21C 1/32 - Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
2.
METHOD FOR CONTROLLING AND PROTECTING A FAST-NEUTRON REACTOR
The invention relates to nuclear engineering, and more particularly to a method for controlling a nuclear reactor, preferably a fast-neutron reactor with a long cycle length and one-to-one dependence between the excess reactivity for fuel burnup and the energy yield of the reactor, in which absorber rods disposed in the core compensate for excess reactivity and perform other functions of a control and protection system. A nuclear reactor is controlled by the movement of absorber rods of an automatic power controller based on a calculation of the positions of the absorber rods which provide an optimal power density field shape for each moment of the cycle (energy yield).
G21C 7/08 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
The invention relates to an absorber element for use in a heavy liquid metal-cooled nuclear reactor. The absorber element (1) comprises a cylindrical outer casing (3) and a cylindrical inner casing (4) that are arranged in axial alignment; a top nozzle (20) and a bottom nozzle (17); a core (5) consisting of a neutron-absorbing material, arranged between the casings (3, 4); a top plug (13) arranged between the top end of the core (5) and the top nozzle (20); a bottom plug (15) arranged between the bottom end of the core (5) and the bottom nozzle (17); and a first separator (7) arranged between the outer casing (3) and the core (5). Between the bottom plug (15) and the bottom nozzle (17), a chamber (23) is formed that is filled with a gas and contains a slug (18) of frozen coolant. The bottom part of said chamber (23) is in fluid communication with the space inside which the core (5) is disposed, formed between the top plug (13) and the bottom plug (15). The top plug (13) has holes (14) that allow for fluid communication between the space inside which the core (5) is disposed and the external environment, wherein said space is filled with frozen coolant in the form of a blank (22) of frozen coolant.
The invention relates to passive heat removal systems for nuclear reactors with a heavy liquid metal coolant (HLMC). The system includes a steam generator with an evaporator and a steam separator; a shutdown cooling heat exchanger; pipes for supplying steam from the steam separator; condensate drainage pipes; isolation valves; and heat removal devices. Mounted on a condensate drainage pipe is a direct-acting shut-off and control device designed to be switchable to a closed state under normal operating conditions in standby modes by the pressure of feedwater or by the force of an electromagnet. To fill the passive heat removal system of the steam generator with a working medium, a valve for supplying steam to a second loop with drained steam generators is opened to supply steam having a pressure that exceeds the saturation pressure at a temperature above the melting point of the HLMC by a given value that is greater than the saturation pressure for the temperature of the HLMC but less than the pressure at which the valve of the shut-off and control device opens. The result is an increase in the operating safety of the apparatus and in the efficiency of the passive heat removal system in the absence of external sources of energy.
The invention relates to nuclear engineering, and more particularly to ensuring the safety of nuclear reactors with heavy liquid metal coolants by means of systems for the guaranteed removal of decay heat, including under blackout conditions. More specifically, the present invention relates to systems for passive shutdown cooling, or systems for the passive removal of heat through a steam generator operating in a once-through mode, for use in nuclear reactors with heavy liquid metal coolants. Use of these systems makes it possible to increase the operating safety of a reactor assembly in the absence of external sources of energy, to prevent solidification of the coolant and to reduce decay heat power.
The invention relates to depots for the dry storage of spent nuclear fuel. The present storage facility for spent nuclear fuel comprises a storage chamber with protective walls, canisters, an upper floor, a lower floor, and a natural ventilation system. The natural ventilation system includes vertical outlet ducts and inlet ducts with air intake devices, and a horizontal inlet header and a horizontal outlet header, between which the lower floor is disposed with receiving tubes mounted therein, the upper floor also having receiving tubes mounted therein in coaxial alignment with the receiving tubes of the lower floor. The receiving tubes of the upper floor have plugs installed therein which separate the storage facility from a space containing a floor-mounted machine for conveying filled spent fuel canisters into the storage facility. The receiving tubes of the lower floor have canisters installed therein, each tube containing either a filled spent fuel canister, or an empty canister with a closure. All of the receiving tubes of the lower floor are closed until loading begins. The invention provides for more effective cooling of spent fuel canisters in the storage facility.
The invention relates to nuclear power engineering and is intended for using in power plants with a reactor with a heavy liquid metal coolant (HLMC) based on lead or on lead-bismuth alloys.
The invention relates to nuclear power engineering and is intended for using in power plants with a reactor with a heavy liquid metal coolant (HLMC) based on lead or on lead-bismuth alloys.
The invention makes it possible to increase the radiation protection efficiency for the in-vessel equipment of a nuclear reactor, to increase the heat storage capacity of the primary circuit, to reduce the nuclear reactor weight, and to improve its strength characteristics.
The invention relates to nuclear power engineering and is intended for using in power plants with a reactor with a heavy liquid metal coolant (HLMC) based on lead or on lead-bismuth alloys.
The invention makes it possible to increase the radiation protection efficiency for the in-vessel equipment of a nuclear reactor, to increase the heat storage capacity of the primary circuit, to reduce the nuclear reactor weight, and to improve its strength characteristics.
In the in-vessel space of a nuclear reactor, which is not occupied by the necessary equipment, containers filled with a material that reflects or absorbs neutrons, with a heat capacity greater than that of the coolant, are installed with gaps ensuring the coolant flow, while the containers are placed in such a way that the resulting gaps form channels with a turbulent coolant flow to cool these containers at a flow rate corresponding to the nominal power output level of the nuclear reactor.
Embodiments of the disclosure may include a reactor vessel with a lower chamber, a core, a hot chamber, an upper chamber, and heat exchangers. In some embodiments, the hot chamber may be located above the core and may include a substantially cylindrical body. In some embodiments, the hot chamber body may include an inner shell and an additional shell installed with a gap on the outside and being concentric with the inner shell of the hot chamber, forming at least one cooling channel. In some embodiments, the connecting pipe may include an inner shell and an additional shell installed with a gap on the outside, being concentric with the inner shell of the connecting pipe and forming at least one cooling channel of the connecting pipe, where the cooling channel of the hot chamber and the connecting pipe are in communication with the outlet of the heat exchangers.
G21C 1/32 - Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
G21C 15/02 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements
The invention relates to the field of nuclear power engineering, and more particularly to the positioning of jacketless fuel assemblies inside the core of a nuclear reactor, and is intended to provide for improved heat removal from the fuel assemblies in a reactor core. The claimed nuclear reactor core comprises hexagonal jacketless fuel assemblies with fuel rods positioned in a triangular grid pattern, the spacing between the rods being greater than the diameter of the cladding thereof. The fuel rods have spiral spacing ribs on their cladding and are rigidly anchored at a set angular orientation so that the fuel rods touch rib-to-rib at a height at which the fuel rod cladding reaches its highest temperature when the reactor is in operation, and the fuel assemblies are positioned so that the fuel rods situated at the edges of the fuel assemblies form a single triangular grid pattern with the other fuel rods in the core and all of the fuel rods in the core touch rib-to-rib at a height at which the fuel rod cladding reaches its highest temperature when the reactor is in operation. Further, incorrect positioning of the fuel assemblies in the core is prevented.
A fastening assembly for a nuclear reactor fuel assembly comprises a fuel-assembly bottom nozzle (1) configured in the form of a tip and secured in a bush (7) of a mounting bore (5) in a lower support plate (2) of the reactor core. The tip (1) has an outer lip (3) with a rounded face (4), the bush (7) is a split bush, and the contacting surfaces of a bottom face (13) of the bush (7) and the outer lip (4) of the tip (1) are in the form of bevelled edges arranged at an angle of (32-40)° relative to the plane of the support plate (2). The claimed fastening assembly for a nuclear reactor fuel assembly provides for secure anchoring of the fuel assembly in the support plate (2) under conditions of prolonged exposure to a liquid-metal coolant.
A fastening assembly for a nuclear reactor fuel assembly comprises a fuel-assembly bottom nozzle (1) which terminates in a collet-type tip (2), the segments (3) of which are provided with outer lips (4) with a rounded face (5) and are fastened in an annular groove (6) of a mounting bore (7) in a lower support plate (8) of the reactor core. On the inner surfaces of the lips (4) of the segments (3) of the collet-type tip (2) of the fuel assembly is an asymmetrical groove (9) having at least one resilient member (10) disposed therein. The structure of the claimed fastening assembly for a nuclear reactor fuel assembly provides for secure anchoring of the fuel assembly in the support plate (8) under conditions of prolonged exposure to a liquid-metal coolant.
The invention relates to a device for protecting a nuclear reactor having a high-temperature coolant. The device comprises an electrical current supply network, absorber rods (4, 4а, 4b) which are insertable into the core for the purpose of emergency protection and which have actuating mechanisms equipped with holding electromagnets, absorber rods (5) for additional emergency protection, and a shared electrical isolator (11) for breaking the current in the electrical current supply network. In the supply network, electrical current passes in series through the windings of the holding electromagnets of all of the absorber rods. Included in the circuit are at least one direct-acting thermal current isolator (8) disposed inside a casing that is insulated from coolant and situated in the flow of hot coolant or at the exit from the core, as well as at least one electrical isolator (11) disposed inside a casing of an absorber rod (5), wherein said casing is insulated from coolant and said isolator is situated higher than the absorbing rod (5), the latter being equipped with a heat-sensitive current isolator (9) with a meltable lock. The technical result is that of providing for the activation of all of the absorber rods in the event of an emergency.
G21C 7/08 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
The invention relates to nuclear engineering, and more particularly to nuclear reactor fuel assemblies, and can be used in nuclear reactors, preferably with liquid metal coolants and particularly with heavy liquid metal coolants. A nuclear reactor core fuel assembly having a square or hexagonal shape comprises fuel rods, the cladding of which is made of ferritic-martensitic class steel that is resistant to corrosion in heavy liquid metal coolants and has spiral ribs arranged equidistantly around the perimeter of the outer surface thereof, a lower grid and an upper grid, and a lock wire passing through openings in end plugs of the fuel rods and slots of one grid of the fuel assembly, the axes of said openings being oriented parallel to one of the edges of the fuel assembly, where said fuel rods are rigidly fastened in one of the grids of the fuel assembly in such a way that for each fuel rod in the fuel assembly, the angle between the axis of the fuel rod end plug opening through which the lock wire passes and the middle of the base of one of the ribs on the fuel rod cladding end in which the end plug with an opening is fastened corresponds to an angle at which the fuel rods are able to touch rib-to-rib at a height at which the fuel rod cladding reaches its highest temperature when the reactor is in operation.
The invention relates to an integral-type nuclear reactor with a heavy liquid metal coolant. The reactor comprises a reactor vessel having a lower chamber, a core, a hot chamber, an upper chamber and heat exchangers. The housing of the hot chamber contains an inner cladding and at least one additional cladding mounted, with clearance, outside of and concentrically with said inner cladding to form at least one cooling duct of the hot chamber. Each branch pipe contains an inner cladding and at least one additional cladding mounted, with clearance, outside of and concentrically with said inner cladding to form at least one cooling duct of the branch pipe. The at least one cooling duct of the hot chamber and the at least one cooling duct of the branch pipe communicate with an outlet of the heat exchangers so that a flow of cooled coolant is directed into said cooling ducts. The technical result is that of reducing the heat load on elements of the hot chamber, primarily the entire housing thereof and the branch pipes for removing hot coolant, and, inter alia, smoothing and reducing the temperature gradient in said elements, and thus increasing the service life thereof.
G21C 15/02 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements
G21C 1/32 - Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
The invention relates to nuclear engineering and is intended for use in power plants having a reactor with a heavy liquid metal coolant based on lead or on alloys based on lead and bismuth. The invention makes it possible to provide more effective radiation protection of equipment inside the reactor vessel, increase the heat accumulation capacity of the primary loop, reduce the weight of the nuclear reactor and improve its strength characteristics. Arranged inside a nuclear reactor vessel, in the space that is not occupied by essential equipment, are containers which are spaced apart to allow the flow of a coolant, said containers being filled with a material that reflects or absorbs neutrons and has a heat capacity greater than that of the coolant, wherein the containers are arranged so that the spaces formed create ducts in which the coolant for cooling said containers has a turbulent flow regime when the flow rate of the coolant corresponds to the nominal power level of the nuclear reactor.
G21C 15/02 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements
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