171results about "Reactors manufacture" patented technology

The invention belongs to the technical field of nuclear fuel preparation, aims to solve the problems of non-uniform particle distribution and high breakage rate in traditional coated particle fuel preparation, and discloses a coated particle dispersion fuel pellet and a preparation method thereof.The method comprises the steps that firstly, silicon carbide slurry is prepared, a silicon carbide base band is prepared through tape casting equipment, and then the silicon carbide base band is prepared; after tape casting, the base band enters a drying area to be partially dried, TRISO particles are arranged on the surface of the base band at set intervals, the silicon carbide base band is freely curled and formed from one end, degreasing treatment and sintering densification are conducted, and the core block is prepared through the method. Through high-precision tape casting and three-dimensional curling technologies, uniform distribution of TRISO particles in CDF is achieved, and the contact and breakage rate of fuel in the preparation process is reduced.

Additive manufacturing compositions include low-absorbing particles or non-absorbing particles that have an absorbance for wavelengths of 300 nm to 700 nm that is equal to or greater than 0 Au and is less 1.0 Au, such as 0.001 Au ≤ absorbance ≤ 0.7 Au. Slurries including such particles and an uranium-containing particle and that are used in additive manufacturing processes have an increased penetration depth for curative radiation. Removal of low-absorbing particles or non-absorbing particles during post-processing of as-manufactured products results in pores that create porosity in the as-manufactured product that provide a volume accommodating fission gases and / or can enhance wicking of certain heat pipe coolant liquids. Low-absorbing particles or non-absorbing particles can be functionalized for improved properties, for example, with fissionable material for improved ceramic yields, with burnable poisons or stabilizers for increased homogeneity, with stabilizers for localized delivery of the stabilizer, or with combinations thereof.

The embodiment of the invention relates to the field of processes specially used for manufacturing a reactor or parts thereof, in particular to an assembling and charging testing method of a reactor using bulk nuclear fuel and the reactor comprising the bulk nuclear fuel. According to the method, loading test is carried out on the reactor by using the test facility after assembly, so that the backup reactivity of the reactor core can be determined, safe assembly and safe criticality of the reactor are realized, and the safety of experimenters is ensured; by gradually adding the partitioned side reflecting layers outside the reactor core formed by the bulk nuclear fuel, the reactor gradually reaches the critical value, the operation risk is reduced, and meanwhile, the critical point can be accurately obtained; after the critical loading of the reactor core is determined, the partitioned side reflecting layers are replaced by the complete side reflecting layers with the same value, so that the influence of gaps existing between the partitioned side reflecting layers can be avoided, and the reaction efficiency of nuclear fuel is improved. The reactor assembled according to the method has high neutron economy and low critical risk.

The present invention relates to a system (1) for extracting UF6 from a UF6 container placed in an autoclave (5), comprising a pump (24) having an inlet port (26) being connected to an upstream supply circuit (10, 20), the upstream supply circuit (10, 20) transporting UF6 from the autoclave to the pump (24); wherein the system further comprises a temperature- controlled subsystem (3) providing a heat supply to the pump (24) and at least a downstream portion of the upstream supply circuit (10, 20), the temperature-controlled subsystem (3) heat supply being adapted to maintain a temperature within the upstream supply circuit and the pump (24) during operation such that said temperature is above the crystallization temperature of UF6.

Described herein is a process for recovering uranium tetrafluoride (UF4) from hexafluoride uranium (UF6), the process comprising dissolving UF6 directly in an ionic liquid and recovering UF4, which can be processed to obtain UO2(s) or metallic uranium.

The invention belongs to the nuclear industry and can be used for the production of fuel pellets from uranium-molybdenum metal powder enriched with uranium-235 to 7%, which can be used as fuel elements for nuclear reactors. The sintering of the pellets is carried out in an inert argon atmosphere at a temperature in the range of 1100°C to 1155°C, as the initial powder, a particle size of 160 μm is used, with a molybdenum content of 9.0 to 10.5 wt.%. The powder is preheated at a temperature of 500°C for 10-20 hours (in an argon medium), and then cold-pressed into pellets in a mold at a pressure of up to 950 MPa. According to another method, when preparing uranium-molybdenum pellets using a binder (plasticizer), the pellets are heated in argon from 300°C to 450°C for a duration of 2-4 hours before sintering, in order to remove the binder. The invention allows to increase the uranium content in the fuel, to reduce the heat accumulated in the core of the nuclear reactor, and to reduce the energy release in the event of a violation of the normal operating conditions of the nuclear reactor, which will improve its safety and emergency stability.

The invention relates to the technical field of nuclear power testing, and discloses a penetration piece for nuclear power equipment testing and a preparation and use method thereof.The penetration piece comprises a connector piece, a sleeve, an abutting piece and an elastic sealing assembly, one end of the connector piece is provided with a first connecting part, and the other end of the connector piece is provided with a second connecting part; a heat dissipation structure is arranged between the first connecting part and the second connecting part of the joint piece, and the first connecting part is detachably connected with the pressure-bearing wall surface of the test container; the open end of the sleeve is movably and detachably connected with the second connecting part; the abutting piece is arranged in the sleeve, and an elastic sealing assembly is arranged between the abutting piece and the sealing end of the sleeve. The connector piece, the abutting piece, the elastic sealing assembly and the sleeve are provided with through penetrating holes. The penetrating piece can adjust the position of the penetrating part; heat dissipation is enhanced through the heat dissipation structure; and the position of the elastic sealing assembly for sealing the penetrating part is far away from the test container, so that the sealing effect at high temperature and high pressure is realized.

Fuel bundle has plurality of twisted ribbon fuel rodlets in hexagonal packing or circle packing arrangement in a core region encased in a multilayer casing. Arrangement of twisted ribbon fuel rodlets is facilitated by rodlet seating fixture with seating surface having a plurality of protrusions that form a receiving space for ends of the twisted ribbon fuel rodlets. Manufacture of the fuel bundle incorporates fiber manufacturing technologies and, optionally, infiltration of void spaces in core region by infiltrant. Twisted ribbon fuel rodlet manufacturing system has sub-systems that impart twist periodicity to extruded ribbons, inspect twisted extruded ribbons, and cut twisted extruded ribbons to length. Inspection sorts twisted ribbon fuel rodlets as well as provides feedback to adjust operation of sub-systems. The fuel bundle (and optional fuel bundle support) can be incorporated into a fuel assembly of a nuclear propulsion fission reactor structure of, for example, a nuclear thermal propulsion engine.

The invention belongs to the technical field of nuclear fuel preparation, and particularly relates to a powder discharging structure used in the annular pellet green pressing process, which comprises an upper punch, a punch sleeve, an upper punch rod and a center rod. The base of the upper punch is used for being installed on the top of an upper punch rod. The punch sleeve is used for penetrating through the upper portion of the upper punch and is in threaded connection with the upper punch rod. A center hole and a powder discharging hole are formed in the upper punch. The powder discharging hole is formed in the side edge of the center hole. One end of the center rod is used for being installed at a center hole of an upper punch, and the other end of the center rod is used for being installed on rotary forming press equipment. The powder discharging hole is formed in the side edge of the center hole of the upper punch, so that the technical problem that the upper punch is prone to breakage due to the fact that powder discharging is not timely in the annular pellet green pressing process is solved.

The invention discloses a fuel assembly guide pipe plug pressing device, and belongs to the technical field of fuel assembly manufacturing. The device comprises a machining platform, bearing plates are symmetrically and fixedly connected to the top of the machining platform, a clamping moving assembly is jointly and fixedly installed on the side walls of the bearing plates, a moving limiting assembly is fixedly installed on the top of the machining platform, a controller is fixedly installed on the side wall of the machining platform, and an alarm lamp is fixedly installed on the top of the controller; according to the invention, by arranging the first electrode plate, the second electrode plate, the alarm lamp and other structures, the outer wall of the end plug, the inner wall of the guide pipe and the side wall of the pipe orifice of the guide pipe can be detected before the end plug is pressed into the guide pipe; if the outer wall of the end plug, the inner wall of the guide pipe and the side wall of the pipe opening of the guide pipe are sunken or protruded, the sliding plate can make contact with the first electrode plate or the second electrode plate, and then the alarm lamp is normally turned on to remind a worker that the end plug or the guide pipe is deformed.

The invention relates to a process for preparing a powder comprising one or more oxides selected from uranium oxide UO2, plutonium oxide PuO2 and minor actinide oxides, the minor actinides being selected from americium, neptunium and curium, comprising the steps of: a) cryogenic granulation of an aqueous solution comprising cations selected from uranium-based cations, plutonium-based cations and minor actinide-based cations; b) freeze-drying of the granules obtained in a); etc.; calcination of the granules from b). Applications: manufacture of nuclear fuels or blankets loaded with minor actinide(s).

The application belongs to the technical field of nuclear energy functional materials and advanced ceramic preparation, and discloses a preparation method of high-uniformity europium hafnate nano-powder based on a complexation-gel method. 3+ With Hf 4+ Atomic-level uniform mixing, solves the microsegregation problem existing in the traditional preparation method, reduces the synthesis temperature, and the product is free of impurities and hard agglomeration, has excellent sintering activity, and is strong in process controllability and easy to be enlarged in engineering, is suitable for the preparation of nuclear reactor neutron absorption control rod materials, and has good industrial application prospect.

We provide a mandrel-wound, splined, monolithic fuel assembly core. [Solution] The fuel assembly core comprises a channel, a fuel monolith containing fissile fuel components and axially arranged, an exhaust support plate, an exhaust shield assembly, and an insulating layer. The fuel monolith has an eccentric cylindrical or straight cylindrical shape with a side surface keyway. The channel in the exhaust support plate is oriented so that the propellant gas does not collide with the exhaust shield assembly. The fuel assembly core is manufactured by forming a fuel monolith stack mandrel assembly and mandrel winding an insulating layer onto the outer surface of the tensioned fuel monolith stack mandrel assembly. The fuel assembly core is incorporated into the fuel assembly of a nuclear propulsion fission reactor structure (e.g., a nuclear thermal propulsion engine).

The application discloses a method for optimizing process parameters of metal type nuclear fuel preparation process, collecting and arranging metal type nuclear fuel preparation process parameters and performance parameters, post-preparation performance parameters and microstructure metallographic pictures; establishing a metal type nuclear fuel solidification phase field model according to a solidification thermodynamic path under different process parameters; solving the metal type nuclear fuel solidification phase field model by using a Fourier spectrum method to obtain a phase field variable numerical solution; post-processing and visualizing the phase field variable numerical solution to generate a microstructure distribution map of the metal type nuclear fuel after solidification, and comparing and verifying the phase field model with the metal type nuclear fuel microstructure metallographic picture; calculating the post-solidification performance parameters of the metal fuel based on the microstructure distribution of the metal type nuclear fuel after solidification; taking the preparation process parameters as input and the performance parameters as output, constructing a nonlinear mapping proxy model between the metal type nuclear fuel preparation process parameters and the performance parameters; and solving the optimal preparation process parameters by using the nonlinear mapping proxy model given the target performance parameters of the metal type nuclear fuel.

The invention relates to a nuclear fuel pellet (6) embedded with a thermally conductive insert (7) in the form of branching arms (7.1 to 7.6) distributed from a hollowed-out inner cylinder (61) towards the outside of the pellet. The invention essentially consists of a nuclear fuel pellet (6) embedded with, within a straight cylindrical ring (60) of fissile material, a thermal conductor (7), in particular a metal conductor, in the form of main branching arms (7.1 to 7.6) that extend from the inside of the ring (60) to the outside and are advantageously distributed homogeneously within the ring. The insert made up of its macrostructure arms and branches makes it possible to reduce the maximum temperature of the fuel by several hundreds of degrees Celsius according to its dimensions, its constituent material and the distribution of its arms in the straight cylindrical fuel ring (60).

The invention discloses a silicon carbide cladding as well as a preparation method and application thereof, and relates to the technical field of silicon carbide cladding preparation. The preparation method comprises the following steps: weaving the fiber ribs on the outer side of the rib-free silicon carbide cladding; the fiber ribs are fixed and formed, densification treatment and silicon carbide deposition are conducted on the end plug portions of the rib-free silicon carbide cladding, and the silicon carbide cladding is obtained; the outer side of the silicon carbide cladding is provided with ribs. According to the preparation method, the problem that a rib type structure is difficult to prepare due to brittleness of silicon carbide is solved, the reliability between the obtained silicon carbide cladding fiber rib and the body is high, the stability is good, and the radial positioning stability of the silicon carbide cladding in a small-spacing fuel assembly is remarkably enhanced when the silicon carbide cladding fiber rib is used for the nuclear reactor fuel assembly.

The reactor core comprises a plurality of core assemblies. The plurality of core assemblies have a cooperative structure formed on one or more load pads that mechanically connects the plurality of core assemblies to each other and restricts the relative motion between the core assemblies in a kinematically determined manner. A shear key on one core assembly is configured to fit into a tab slot on an adjacent core assembly. The motion of one core assembly is transmitted to a second core assembly, and these core assemblies move together.

The invention relates to the technical field of concrete pouring, in particular to a containment concrete pouring construction structure and method.The construction structure comprises a containment concrete body, the containment concrete body is composed of a plurality of pouring sections which are sequentially connected in the height direction, and a plurality of pouring layers are arranged in each pouring section in the height direction; a construction joint is formed between every two adjacent pouring sections; the template is arranged on the outer side of the containment concrete body; and the connecting devices are arranged corresponding to each single pouring section, one end of each connecting device is connected with the corresponding pouring section, and the other end of each connecting device is connected with the corresponding formwork so as to fix the position of the corresponding formwork. Segmented and layered control over concrete pouring is achieved, and the construction quality can be accurately controlled.

This invention provides a sandwich-toughened ceramic-based fuel element and its additive manufacturing method, belonging to the field of nuclear reactor fuel technology. The element includes an outer shell and an inner shell, with an annular gap between them forming a sandwich space containing a silicon carbide whisker toughening structure. The method includes: additively manufacturing a double-layer shell, the geometry of which can be flexibly designed; preparing the sandwich toughening structure, which can be formed by injecting SiC whisker slurry into the sandwich space and solidifying it, or by generating self-grown whiskers in situ within the sandwich space through heat treatment of a Si and C raw material system; subsequently performing chemical vapor infiltration pretreatment; completing fuel loading and opening end sealing; and further performing enhanced CVI densification treatment. This invention introduces a sandwich toughening structure without significantly increasing the structural complexity of the element, effectively improving the fracture toughness, crack resistance, structural stability, and service stability of SiC-based fuel elements.

The invention belongs to the field of nuclear fuel cladding material surface engineering, and particularly relates to a gradient structure protective coating and a preparation method and application thereof. According to the method, the Cr layer, the Cr-Al-Si layer and the Cr-Al-Si-N layer are sequentially deposited, a three-layer structure with components and density in gradient transition is constructed, interlayer stress concentration is effectively avoided, and the binding force and toughness are improved. Wherein the grain size of the Cr-Al-Si intermediate layer is 25-45nm, and the Cr-Al-Si intermediate layer can accommodate and combine irradiation point defects; the surface Cr-Al-Si-N layer is of a composite structure with 5-15 nm nanocrystals wrapped by an amorphous matrix, a rapid defect annihilation channel is provided, and the anti-irradiation performance is synergistically enhanced. The method is completed through single-period sequential deposition, the process is easy and convenient to control, reproducibility is good, industrialization implementation is easy, and the prepared coating has excellent radiation resistance, high-temperature water vapor oxidation resistance and good film-substrate bonding strength.

There is disclosed a method for producing a compact nuclear fuel form. The process comprises obtaining a plurality of kernels, the plurality of kernels comprising a first set of kernels each comprising nuclear fuel and, optionally, one or more sets of unfuelled kernels, arranging the plurality of kernels within a container, and applying at least one coating layer to the plurality of kernels within the container wherein, after applying the at least one coating layer, the plurality of kernels become bound together.

The invention belongs to the technical field of nuclear power, and particularly relates to a sintering method of a UO2 fuel pellet taking direct ammonia decomposition gas as a raw material. Preparing nitrogen and hydrogen required for producing the UO2 fuel pellet by taking ammonia gas as a raw material; ammonia gas is subjected to a thermocatalytic ammonia decomposition reaction to generate ammonia decomposition gas, and the ammonia decomposition gas comprises ammonia gas, hydrogen and a small amount of ammonia gas which is not completely decomposed; ammonia gas which is not completely decomposed in the ammonia decomposition gas is removed to form mixed gas of hydrogen and nitrogen; and after being humidified, mixed gas of nitrogen and hydrogen is introduced into the sintering furnace to participate in preparation of the UO2 fuel pellet. According to the UO2 pellet sintering method using the direct ammonia decomposition gas as the raw material, the reaction gas required by pellet sintering can be obtained only by carrying out one-time thermal decomposition reaction and one-time purification operation on the gas, and then an original whole sintering system is simplified.

This invention discloses an automated MOX module chip loading device and production system. The automated MOX module chip loading device includes an MOX chip feeding mechanism, a depleted uranium chip feeding mechanism, a cladding tube storage mechanism, a pusher mechanism, and a chip transport mechanism. The chip transport mechanism includes a first glove box and a chip transport assembly, used for movement between a first station, a second station, and a third station within the first glove box. The depleted uranium chip feeding mechanism includes a depleted uranium chip feeding assembly and a second glove box, which is connected to the first glove box at a second station, used to push the stacked depleted uranium chips onto the chip transport assembly. The MOX chip feeding mechanism includes a MOX chip feeding assembly and a third glove box, which is connected to the first glove box at a first station. The MOX chip feeding assembly is used to push the stacked MOX chips onto the chip transport assembly, and the pusher assembly is used to push the chips into the cladding tube. The automated MOX module chip loading device has a high degree of automation.

The invention relates to a warm-pressing forming preparation method for preparing a bent plate type fuel element through a flexible forming mold. The warm-pressing forming preparation method comprises the steps that a metal-based flat plate type fuel element is heated to the annealing temperature, and heat preservation is conducted for a first time under the condition of the annealing temperature; the upper die assembly is preheated, and heat preservation is conducted for a second duration under the condition of the preheating temperature; placing the annealed metal-based flat plate type fuel element on a flexible die body; the upper die assembly is pressurized, so that the metal-based flat plate type fuel element is formed into a bent plate type fuel element under the support of the flexible die body; the upper mold assembly is pressurized for a third time length, and the waste heat of the flexible forming mold in the pressurizing process is used for preserving the heat of the bent plate type fuel element. In the pressing process, the lower surface of the fuel element is completely attached to the upper surface of the flexible die body all the time, and local stress concentration is avoided. And the annealing temperature is in the lower limit interval of the recrystallization temperature, so that the yield strength of the fuel element is effectively reduced, and meanwhile, the mechanical property is prevented from being greatly reduced.

A nuclear reactor coated cladding may include a steel cladding having opposed interior and exterior surface and a coating disposed on the interior surface, wherein: the coating is a thermal and radiation resistant multilayer coating comprising: a ceramic layer in contact with the steel cladding, a metal oxide region separated from the ceramic layer by a metal layer, a metal nitride region separated from the metal oxide region by a metal layer, and the metal nitride region comprises at least two metal nitride layers, the metal oxide region comprises at least two metal oxide layers, each metal oxide layer and each metal nitride layer is separated from an adjacent layer by a metal layer, and a thickness of the metal layers in the metal nitride region is greater than a thickness of at least one of the metal layers in the metal oxide region.

A nuclear fuel assembly and a method of manufacture thereof are provided. The method comprises depositing a thermally conductive layer onto at least a portion of at least two nuclear fuel layers to create at least two at least partially coated layers. The method comprises stacking the at least two coated layers and bonding the at least two coated layers to form a nuclear fuel assembly.

The invention relates to a method for constructing an underground nuclear installation on a site (10) comprising a shaft (12) bored into the ground (14, 16) and defining a bottom (12a), at a given depth relative to the ground surface, and an opening (12b, 12b1, 12b2) located at the level of the ground surface surrounding the shaft. The method comprises the following phases: - construction of a protective slab (D1, D2; D; 230) against external aggressions on an area (Zcd) of the ground surface, referred to as the slab construction area, located next to the opening (12b, 12b1, 12b2) of the shaft, - construction of a reactor building (B1, B2) inside the shaft (12), the phases of construction of the protective slab (D1, D2; D; 230) and the reactor building (B1, B2) being carried out in parallel. Figure for the abridged version: Fig. 3

Fuel, intended to be irradiated in a fast neutron nuclear reactor, comprising grains of at least one metal selected from U, Pu or Th, the grains being compressed in a volume, the fuel being porous, the fuel being characterized in that it comprises open intergranular pores, forming an interconnected porosity, the volume fraction of porosity preferably being between 3% and 30%, more than 50% or 80% of the porosity being an open intergranular porosity,

A nuclear fuel assembly and a method of manufacture thereof are provided. The method comprises depositing a thermally conductive layer onto at least a portion of at least two nuclear fuel layers to create at least two at least partially coated layers. The method comprises stacking the at least two coated layers and bonding the at least two coated layers to form a nuclear fuel assembly.