375results about "Moderator/core" patented technology

A nuclear reactor is discussed herein. In some examples, the nuclear reactor may comprise an inner-core region, including liquid fuel, coolant / moderator, and a hydrogen vapor space, an out-of-core region surrounding the inner-core region, the out-of-core region including, an inner reflector adjacent to the inner-core region, the inner reflector including a first irradiation facility, and an outer reflector adjacent to the inner reflector, the outer reflector including a second irradiation facility.

Carbide-based fuel assembly includes outer structural member of ceramic matrix composite material (e.g., SiC—SiC composite), insulation layer of porous refractory ceramic material (e.g., zirconium carbide with open-cell foam structure or fibrous zirconium carbide), and interior structural member of refractory ceramic-graphite composite material (e.g., zirconium carbide-graphite or niobium carbide-graphite). Spacer structures between various layers provide a defined and controlled spacing relationship. A fuel element bundle positioned between support meshes includes a plurality of distributively arranged fuel elements or a solid, unitary fuel element with coolant channels, each having a fuel composition including high assay, low enriched uranium (HALEU). Fuel assemblies are distributively arranged in a moderator block and the upper end of the outer structural member is attached to a metallic inlet tube for hydrogen propellant and the lower end of the outer structural member is interfaced with a support plate, forming a nuclear thermal propulsion reactor.

The preparation method of the aluminum oxide hydrogen-resistant coating on the zirconium hydride surface disclosed by the embodiment of the invention comprises the following steps: S1, plating aluminum on the surface of a zirconium hydride matrix in a magnetron sputtering manner, and forming an aluminum film on the surface of the zirconium hydride matrix; and S2, the aluminum film formed on the surface of the zirconium hydride matrix is subjected to micro-arc oxidation to obtain aluminum oxide, and the aluminum oxide hydrogen-resistant coating is obtained. Wherein an aluminum oxide film layer formed on the surface of zirconium hydride is tightly combined with a zirconium hydride matrix, and the thickness of the film layer is 5-80 microns; the aluminum oxide film layer is composed of an inner compact layer with a non-porous structure and an outer loose layer with a closed pore structure, the thickness of the compact layer is 2-15 microns, and the compact layer has a good hydrogen permeation resistance effect; the aluminum oxide film layer on the surface of zirconium hydride can serve as an aluminum oxide hydrogen-resistant coating, the hydrogen-resistant capacity of the zirconium hydride moderator is improved, and the service life of the zirconium hydride moderator is prolonged.

The invention provides a reactor core structure capable of controlling an assembly clearance and a manufacturing method thereof. The reactor core structure comprises a reactor core heat management element and a filling material; wherein the base body is provided with a plurality of assembly holes; the reactor core heat management element comprises a fuel rod or a heat pipe; the reactor core heat management element is assembled in the assembly hole of the base body; the filling material is filled in an assembly gap between the reactor core heat management element and the assembly hole; and the filling material is a shape memory alloy. The reactor core structure can improve the safety margin of the heat pipe reactor.

An installation includes: a plurality of pilings securable to a bed under a surface of a body of water; a base structure disposed atop the plurality of pilings; and a module disposable on the base structure, wherein the module is positioned and securable on the base structure after being floated on the surface of the body of water over the base structure.

The invention provides a doped yttrium hydride neutron moderation material and a preparation method and application thereof, and belongs to the technical field of radiation shielding materials. At least one of samarium, europium and gadolinium is doped in yttrium hydride in the form of hydride, and the mass ratio of metal yttrium to metal gadolinium to metal europium to metal samarium is controlled, so that the neutron moderation effect of the neutron moderation material can be improved. According to the invention, at least one of gadolinium hydride, europium hydride and samarium hydride is mixed with yttrium hydride under the protective atmosphere, so that the mass content of each element in the doped yttrium hydride neutron moderation material can be accurately controlled. According to the invention, the mixture is sintered and molded, and the sintering parameters of sintering and molding are controlled, so that the components of the mixture are sintered in a compact state, cracks generated by thermal expansion and cold contraction can be reduced, and the doped yttrium hydride keeps high density and has fewer cracks and defects.

The invention provides a supercritical reactor, which comprises a pressure vessel cylinder, a reactor internal is arranged in the pressure vessel cylinder, and the reactor internal accommodates a peripheral fuel assembly and a middle fuel assembly; an inlet connecting pipe and an outlet connecting pipe are arranged on the pressure container barrel, a lower cavity is formed in the bottom of the pressure container barrel, and one ends of the peripheral fuel assembly and the middle fuel assembly extend to the lower cavity or are arranged above the lower cavity; coolant introduced by the inlet connecting pipe flows to the lower cavity through the peripheral fuel assembly and returns to the middle fuel assembly so as to be discharged from the outlet connecting pipe. The peripheral fuel assembly and the middle fuel assembly are arranged, a coolant entering through the inlet connecting pipe is heated downwards through the peripheral fuel assembly and then enters the middle fuel assembly to be heated, the two-flow reactor core design is adopted, fast reactor core and thermal spectrum series connection are achieved, the height of the reactor core and the density change of the coolant can be reduced, and the reactor core is more compact. The reactor core height neutron distribution is more uniform, the temperature level of a fuel cladding is reduced, and the fuel circulation characteristic is improved.

Insulated fuel assembly core with plurality of fuel monoliths, exhaust support plate, exhaust shield assembly, and insulation layer in which the plurality of fuel monoliths are located axially along a longitudinal axis and each of the plurality of fuel monoliths has a shape of an eccentric cylinder and a composition including a fissionable fuel component. Channels in the exhaust support plate are oriented so that propellant gas flow through the exhaust support plate does not impinge the exhaust shield assembly. The insulated fuel assembly core is manufactured by forming a tensioned fuel monolith stack mandrel assembly using mandrels spacers and internal tensioning components and forming an insulation layer on an outer surface of the tensioned fuel monolith stack mandrel assembly by mandrel winding. The insulated fuel assembly core can be incorporated into a fuel assembly of nuclear propulsion fission reactor structure of, for example, a nuclear thermal propulsion engine.

The invention belongs to the technical field of production of isotopes by a sodium-cooled fast reactor, and aims to solve the problems that the moderation effect is limited, the reactor core disturbance is relatively large and fast neutron energy spectrum is not beneficial to the production of the ultra-uranium isotopes during the production of the ultra-uranium isotopes. The invention provides a method for producing a super-uranium isotope by using a sodium-cooled fast reactor and a sodium-cooled fast reactor core. According to the method, moderator assemblies and super-uranium isotope production assemblies are arranged on a first circle of a radial conversion area in a flower arrangement mode, the super-uranium isotope production assemblies are arranged on a second circle of the radial conversion area, and the side, facing the center of the reactor core, of the first circle is coated with a thermal neutron absorption material; the reactor core is provided with a radial conversion area, moderator assemblies and super-uranium isotope production assemblies are arranged on a first circle of the radial conversion area, the super-uranium isotope production assemblies are arranged on a second circle of the radial conversion area, and thermal neutron absorbing materials are arranged on the side, facing the center of the reactor core, of the first circle. The super-uranium isotope is concentrated in the radial conversion region for production, the moderation effect is good, the disturbance to the reactor core is small, and the productivity is high.

The invention belongs to the technical field of heat pipe reactors, and discloses a hexagonal annular heat pipe cooling reactor, which comprises a pipe wall of a heat pipe, a silk screen wick, a steam cavity structure of the heat pipe, uranium-molybdenum alloy fuel, an outer pipe wall of the heat pipe, a wick attached to the inner wall surface of the heat pipe, and uranium-molybdenum alloy. The device is formed by coupling a hexagonal annular heat pipe with a hexagonal fuel element. Firstly, in the aspect of the structure, a framework structure composed of graphite is not needed to fix the heat pipe and the fuel element, an assembly composed of the heat pipe and the fuel element can be directly adopted for expansion to form the fuel element, and gap thermal resistance brought by the framework is eliminated. In addition, in terms of heat transfer performance, the heat transfer performance of the hexagonal annular heat pipe is superior to that of a traditional cylindrical heat pipe. The same heat transfer area is adopted, and under the condition of the same heat transfer power, the temperature of the outer surface of the pipe wall of the hexagonal annular heat pipe is lower than that of a cylindrical heat pipe. Therefore, the material stress requirement in the heat pipe pile and the thermoelectric conversion form of the condensation section can be richer.

This invention discloses an in-core component with highly uniform core outlet flow rate and its design method, relating to the field of nuclear reactor design technology. It solves the problem of poor uniformity in coolant flow distribution at the core outlet in existing reactors, balances flow resistance at various points at the core outlet, and reduces lateral flow between different channels. The specific solution is as follows: it includes a core top plate and a support column assembly mounted above the core top plate. The core top plate is provided with several water flow holes and mounting holes. The water flow holes consist of circular and square water flow holes. The circular water flow holes are divided into first and second circular water flow holes with different functions. The area ratio of the square water flow holes to the circular water flow holes is 1.1:1 to 1.3:1.

The invention provides a reactor core structure capable of improving an assembly clearance and a manufacturing method thereof. The reactor core structure comprises a reactor core heat management element and a filling material; wherein the base body is provided with a plurality of assembly holes; the reactor core heat management element comprises a fuel rod or a heat pipe; the reactor core heat management element is assembled in the assembly hole of the base body; the filling material is filled in an assembly gap between the reactor core heat management element and the assembly hole; the filling material is a foam porous material, and the pore diameter of the foam porous material is micron-sized. The reactor core structure can improve the safety margin of the heat pipe reactor.

Carbide-based fuel assembly includes outer structural member of ceramic matrix composite material, the interior surface of which is lined in higher temperature regions with an insulation layer of porous refractory ceramic material. A continuous insulation layer extends the length of the fuel assembly or separate insulation layer sections have a thickness increasing step-wise along the length of the fuel assembly from upper (inlet) section towards bottom (outlet) section. Fuel element positioned inward of the insulation layer and between support meshes has a fuel composition including HALEU and the form of a plurality of individual elongated fuel bodies or one or more fuel monolith bodies containing coolant flow channels. Fuel assemblies are distributively arranged in a moderator block, with upper end of the outer structural member attached to an inlet for propellant and lower end of the outer structural member operatively interfaced with a nozzle forming a nuclear thermal propulsion reactor.

A nuclear reactor core includes a plurality of fuel elements and moderator blocks to form a nuclear reactor core inner portion and a nuclear reactor core outer portion. The nuclear reactor core inner portion includes an inner moderator matrix formed of a plurality of inner holes that include a plurality of inner fuel openings with one or more fuel elements disposed therein. The plurality of inner holes further include a plurality of inner coolant passages to flow a coolant. The nuclear reactor core outer portion includes an outer moderator matrix formed of a plurality of outer holes that include a plurality of outer fuel openings with one or more fuel elements disposed therein. The plurality of outer holes further include a plurality of outer coolant passages to flow the coolant. The outer coolant passage diameter exceeds the inner coolant passage diameter.

The invention discloses a treatment method for blocking open pores of nuclear graphite by adopting a silicon carbide nanostructure so as to prevent molten salt and molten metal from infiltrating graphite. Comprising the following steps: 1) mixing polycarbosilane and an organic solvent according to a mass concentration ratio of 50%-70% to form a solution, adding a catalyst to serve as a precursor solution, and completely immersing the precursor solution into graphite pores through vacuum infiltration or pressure infiltration; 2) placing the infiltrated graphite in a closed environment of 70-200 DEG C, hydrolyzing and curing the precursor solution to form a gel network, then drying in a vacuum environment of 0-300 DEG C, and forming an aerogel precursor in graphite holes; and 3) in an inert gas atmosphere or a vacuum environment, heating to 1300-1800 DEG C, and pyrolyzing the aerogel precursor to form the silicon carbide nanostructure. Compared with a traditional method, the method has the advantages of simple process, difficulty in failure, no change of the original performance of graphite and the like, and has relatively high economic value and application prospect.

The invention provides a reactor internal capable of realizing integral movement of a reactor core, and relates to the technical field of research, development and design of reactor body structures, the reactor internal comprises a hanging basket barrel, a reactor core shroud and a reactor core; the reactor core is arranged in the reactor core shroud; the reactor core shroud is arranged in the hanging basket barrel body, the reactor core shroud is movably connected with the hanging basket barrel body, the reactor core shroud slides up and down in the hanging basket barrel body, and the bottom of the hanging basket barrel body supports the reactor core shroud. According to the invention, the material changing and maintenance efficiency can be effectively improved, the downtime is shortened, the safety is enhanced, the personnel radiation exposure risk is reduced, the inspection and maintenance are convenient, and the service life of equipment is prolonged. The system adapts to advanced reactor design and conforms to the development trend of modularization and high efficiency, and the performance, safety and economical efficiency of the nuclear reactor are remarkably improved through the design of the system.

Molten salt nuclear fission reactor comprising a core through which a fuel salt flows, means (30, 31) for circulating the fuel salt, a primary heat exchanger through which a heat-transfer salt flows, a primary enclosure which is impermeable to liquid salts and contains the reactor core, and a shelter. The reactor comprises a parallelepiped matrix (10) comprising alternating layers (11) of fuel salt channels, and layers (12) of heat-transfer salt channels. The matrix forms both the reactor core, in which the fission occurs, and the primary heat exchanger of the reactor. The means for circulating the fuel salt are entirely located within the primary enclosure and are configured to extract the fuel salt from one portion of the fuel salt channels on one side of the matrix and to propel the fuel salt into the other portion of the channels on the same side of the matrix.

A nuclear power generation system capable of generating power with robust shielding against ionizing radiation is provided. This nuclear power generation system includes: a nuclear reactor that includes a core fuel, and a reactor vessel that surrounds to cover the core fuel and to shield a space having the core fuel for shielding against ionizing radiation; a thermal conductor that is disposed inside of the reactor vessel, and transfers heat of the core fuel via solid thermal conduction; a refrigerant circuit that includes a pipe with a part inserted in the reactor vessel and another part disposed outside of the reactor vessel, and through which refrigerant is passed, and that circulates the refrigerant exchanging heat with the thermal conductor; a turbine that is rotated by the refrigerant circulating through the refrigerant circuit; and a generator that is rotated integrally with the turbine.

Flow channels are formed into a nuclear reactor core receptacle and provide a flow path for leaking primary coolant. The flow path redirects the leaking coolant from an upwardly vertical direction, in which the mass flow would impart a lift off force to a core assembly seated within the receptacle, to a horizontal flow path direction which maintains hydraulic balance of the core assembly. The flow channels in the nuclear reactor core receptacle provide a passive measure to allow hydraulic hold down of the core assemblies even in the absence of mechanical hold downs.

To provide a nuclear reactor which is safe and requires a low electricity charge by reducing the output density of nuclear power generation discharging no carbon dioxide to increase the safety, thereby making power generation cost higher than surface-derived energy power generation.SOLUTION: In a two-region breeder reactor with a core and blanket, a heavy noble gas coolant (3000) is circulated for cooling in a cylindrical shielding container (2000) containing a cylindrical U-Pu-MA mixed metal (100) and a doughnut-shaped blanket metal (1000) and The cylindrical U-Pu-MA mixed metal (100), which is made movable, is inserted into and withdrawn from the hollow part of the doughnut-shaped blanket metal (1000) to control the reactor output.SELECTED DRAWING: Figure 1

A masking element with an opening is disposed on the side of a core support structure. A flow stack wall defines a plurality of inlets. At least one inlet aligns with the masking element opening when the flow stack is mated with the masking element. A flow control assembly within the flow stack is configured to restrict flow of fluid within the flow stack.

A nuclear reactor (1) comprises: a vessel (2) closed at the top by a cap (3) and containing a core (4) comprising a bundle of fuel elements (5) and immersed in a primary fluid (F) for cooling the core (4); and a heat exchanger (40) for removing heat from the primary fluid (F) by means of a secondary fluid circulating in the heat exchanger (40); the core (4) is supported by a lower support (90) supporting a lower portion of the core (4) below the active zone of the fuel elements (5) and an upper support (80) supporting an upper portion of the core (4) above the active zone of the fuel elements (5); the upper support (80) is joined to the top cover (3) by a support structure (6) extending from the top cover (3) and has an end element (16) which is open centrally and internally provided with a plurality of clamping elements (14) for vertically supporting and resiliently radially constraining the fuel element (5).

A nuclear reactor is designed to couple the load path of the control elements with the reactor core, thus reducing the opportunity for differential movement between the control elements and the reactor core. A cartridge core barrel can be fabricated in a manufacturing facility to include the reactor core, control element supports, and control element drive system. The cartridge core barrel can be mounted to a reactor vessel head. Thus, any movement, such as through seismic forces, transmits an equal direction and magnitude to the control elements and the reactor core. This arrangement reduces the opportunity for differential movement between the control elements and the reactor core.

A fuel assembly comprises a fuel assembly intermediate structure 250 circumferentially enclosing an interior volume, a fuel element bundle 190 located within the interior volume with the fuel assembly intermediate structure radially outward of the fuel element bundle, an insulation layer 160 radially outward of the fuel assembly intermediate structure 250, a void space 255 between an inner surface of the insulation layer 160 and an outer surface of the fuel assembly intermediate structure 250, a fuel assembly outer structure 110 radially outward of the insulation layer 160, and a second void space 265 between an outer surface of the insulation layer 160 and an inner surface of the fuel assembly outer structure 110. The fuel element bundle includes a plurality of fuel elements 105 and a coolant flow volume 115, through which a coolant in a form of a propellant gas flows during operation of a reactor containing the fuel assembly, so that the coolant contacts exterior surfaces of the fuel elements 105.

The present invention relates to the field of nuclear power engineering, namely the placement of unsheathed fuel assemblies in a nuclear reactor core, aiming to improve the heat dissipation of fuel elements in a nuclear reactor. The nuclear reactor core comprises a hexagonal unsheathed fuel assembly having fuel elements located on a triangular grid with a spacing greater than the diameter of the fuel element cladding. The fuel elements comprise spiral spacer ribs on the cladding and are rigidly fixed in a given angular direction so that the fuel elements are in rib-to-rib contact at a height position at which the fuel elements reach the maximum fuel element cladding temperature during reactor operation. The fuel assembly is positioned in such a way that the fuel elements located on the surface of the fuel assembly form a single triangular grid with the remaining fuel elements in the core, and ensure that all the fuel elements are in rib-to-rib contact at a height position at which the highest fuel element cladding temperature is reached during reactor operation. At the same time, incorrect placement of the fuel assembly in the core is eliminated.

In many embodiments, a plurality of neutron moderators may be arranged to define a plurality of flow channels within a reactor vessel, wherein each neutron moderator of the plurality of neutron moderators includes at least one surface face, and each neutron moderator is not machined. In some embodiments, the flow channel may be defined by the at least one surface face of each neutron moderator of the plurality of neutron moderators. In at least one embodiment, the plurality of neutron moderators may include at least three neutron moderators. In several embodiments, the plurality of neutron moderators may include a first pair of neutron moderators and a second pair of neutron moderators. In one or more embodiments, the first pair of neutron moderators and the second pair of neutron moderators may be arranged to form a lattice configuration in a reactor vessel.

A nuclear fission power plant (10) comprising: a nuclear reactor core (20) comprising a fuel system (30) and a moderator (35); a plurality of heat pipes (40) that each at least partially extend within the core; a neutron reflector (70) disposed around the core; a plurality of primary neutronic control elements (50) disposed around the core; a secondary neutronic control element (60) configured to be inserted into a void in the core; a fluid circuit (90) comprising a first heat exchanger (92), a second heat exchanger (96), and a pump (94); and an open Brayton power system comprising: a compressor (102); one or more turbines (104, 106); and a generator (108), and being arranged such that air flows through the compressor, the second heat exchanger and the one or more turbines, wherein the second heat-exchanger is configured to permit heat from the core to be transferred to the compressed air from the compressor, and the one or more turbines drive the compressor and the generator.

To enable reactivity control using a simplified configuration.SOLUTION: A nuclear reactor 201 is provided, comprising: a core section 11 not including nuclear fuel; and a plurality of fuel drums (fuel units) 251 arranged so as to surround the core section 11, and each having a neutron absorbing part 55 for absorbing neutrons and a nuclear fuel part 56, where positions of the neutron absorbing part 55 and the nuclear fuel part 56 are adjustable relative to the core section 11.SELECTED DRAWING: Figure 3

A curvilinear electromagnetic pump is configured to follow a curve, such as by joining together multiple linear pump segments offset at an angle relative to one another. A curvilinear electromagnetic pump can be curved in two dimensions or in three dimensions. A curvilinear electromagnetic pump allows for more efficient placement of components and systems within a reactor vessel, significantly reducing the height of the reactor vessel compared to vertically positioned linear pumps. A curvilinear electromagnetic pump can follow the curvature of the reactor vessel wall and can be positioned generally near the bottom of the reactor vessel.

There is provided a nuclear reactor 21, 23 comprising a reactor vessel (37, Fig. 6) having a central longitudinal axis (30) defining an upper (40) and lower (42) end. Within the reactor vessel is an i