31results about "Fuel elements" patented technology

A coupon sampler for a reactor system includes a lower assembly having an in-line portion configured to receive a flow of a molten salt, and a lower assembly pipe portion extending transverse from the in-line portion and defining a lower channel therethrough. The coupon sampler further includes an upper assembly fluidically coupled with the lower assembly. The upper assembly includes an upper assembly pipe portion defining an upper channel therethrough and cooperating with the lower channel to define a sampling channel of the coupon sampler. The coupon sampler further includes a coupon device disposed fully within the sampling channel. The coupon sampler further includes an actuation mechanism operatively coupled with the coupon device and configured to move the coupon device axially into and out of the flow of the molten salt.

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.

A fuel assembly (100) for a nuclear fission reactor system (110). The fuel assembly (100) may comprise a pressure tube (120) comprising an aluminium or aluminium alloy. The fuel assembly (100) may comprise a sleeve member (132), the sleeve member (132) extending along a radially inner surface (134) of the pressure tube (120). The fuel assembly (100) may comprise a fuel compact unit (136). The fuel compact unit (136) may be located within the sleeve member (132)) such that a clearance is maintained between a radially inner surface (139) of the sleeve member (132) and the fuel compact unit (136) to define a sleeve member flow passage (140).

Heat pipe fuel element includes an evaporation section, a condensing section, a capillary section connecting the evaporation section to the condensing section, and a primary coolant. In a cross-section in a plane perpendicular to a longitudinal axis of the evaporation section, the heat pipe fuel element includes a cladding layer enclosing an interior area including a fuel body formed of a fissionable fuel composition and that has an outer surface oriented toward the cladding layer and an inner surface defining a periphery of a vaporization space of the evaporation section. The fuel body has a structure with a shape corresponding to a mathematically-based periodic solid, such as a triply periodic minimal surface (TPMS), and the evaporation sections of a plurality of heat pipe fuel elements are arranged in a phyllotaxis pattern (as seen in a cross-section in a plane perpendicular to a longitudinal axis of the active core region).

The invention relates to a fuel rod for a water-cooled water-moderated nuclear reactor. In the proposed fuel rod, there is disposed below the fuel column a spacing element which forms a bottom plenum space and which is pressed against a bottom plug by the fuel column with the aid of a fastening spring. The spacing element consists of a housing in the form of a tube, which has stoppers press-fitted to the ends thereof, said stoppers having axially aligned through-openings and having slots in the outer end faces thereof for admitting helium into the inner cavity of the spacing element. The bottom plug has a stepped profile, and the middle portion thereof, which is disposed outside the cylindrical cladding, has a diameter that is greater than the outside diameter of the cylindrical cladding. The bottom end of the bottom plug has a toroidal surface, the cross-section of which is not greater than the outside diameter of the cylindrical cladding. The technical result is that of increasing the fuel charge, improving the energy efficiency and increasing the operating reliability and safety of a fuel rod for a water-cooled water-moderated nuclear reactor, as well as simplifying the assembly process, and facilitating repair in the event of depressurization of the fuel rod.

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.

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.

A thermal transfer unit may include one or more modules having a surface to volume ratio of greater than four hundred square meters per cubic meter. One or more of said modules may include a fluid inlet portion. Said fluid inlet portion may include a fluid inlet surface. One or more of said modules may include a thermal interface portion configured to interface with and thermally couple to an object for temperature regulation of the object. Said thermal interface portion may include a fluid return surface. Said module may include a matrix of pores configured to effect fluid flow. Said module may include a plurality of fluid return channels extending from said fluid return surface to an outlet. Said module may include a matrix of pores on or proximate said fluid inlet surface. Said module may include a matrix of pores on or proximate said fluid return surface.

The application particularly relates to a plate type element edge positioning method, comprising the following steps: step 1, obtaining images of a fuel cladding and a fuel core through X-ray imaging; step 2, establishing a coordinate system in the images to obtain the relative positions of each vertex of the fuel and each vertex of the fuel core, and establishing a reference coordinate system for cutting the fuel cladding; step 3, obtaining the coordinates of each vertex of the fuel cladding and each vertex of the fuel core in the reference coordinate system; and step 4, cutting the fuel cladding according to the coordinates of each vertex of the fuel cladding and each vertex of the fuel core in the reference coordinate system. The plate type element edge positioning method realizes the accurate positioning of the fuel core in the fuel cladding, improves the cutting accuracy, and avoids cutting into the fuel core in the fuel cladding to damage the structure of the fuel core when the fuel cladding is cut.

A nuclear fuel rod comprises nuclear fuel contained in a cladding, the cladding comprising a tube and two plugs, the tube extending along a central axis and having two ends, each plug being attached to a corresponding end of the tube by sealing the end of the tube. The tube is covered by a tube coating extending over the entire length of the tube from one end of the tube to the other.

The application discloses a spliced fuel assembly structure and a reactor core, which can connect integrated channels of two fuel assembly bodies through a connecting sleeve, and reduces the leakage problem caused by the flow of coolant between the two fuel assembly bodies. The spliced fuel assembly structure comprises the fuel assembly bodies and the connecting sleeve. The number of the fuel assembly bodies is two; the fuel assembly bodies are internally provided with the integrated channels, the integrated channels are arranged along the axial direction of the fuel assembly bodies, and the integrated channels are used for guiding the coolant; the two fuel assembly bodies are oppositely arranged along the axial direction, and the two fuel assembly bodies are both provided with positioning holes on the two opposite end faces, and the positioning holes are communicated with the integrated channels in the corresponding fuel assembly bodies. The two ends of the connecting sleeve are matched with the two positioning holes, and the two ends of the connecting sleeve are respectively inserted into the two positioning holes; the connecting sleeve is internally provided with a communicating hole, and the communicating hole is communicated with the integrated channels of the two fuel assembly bodies, so that the coolant can flow in the two fuel assembly bodies.

This invention relates to the field of spherical nuclear fuel element molding technology, specifically to an isostatic pressing molding die and a method for preparing spherical fuel element blanks. The isostatic pressing molding die includes an isostatic pressing core ball mold for pressing the core ball and an isostatic pressing molding die for pressing the spherical fuel element blank. It consists of at least a die body and an inverted conical top cover for closing the opening of the die body. After mold closing, both the internal cavity and the external shape are spherical. The die material is one of nitrile rubber, silicone rubber, EPDM rubber, natural rubber, and polyurethane. When preparing spherical fuel element blanks using this die, nuclear fuel and matrix graphite powder are first filled into the die body of the core ball mold and stirred evenly. After mold closing, it is vacuum-sealed and isostatically pressed to obtain the core ball. Then, the core ball and matrix graphite powder in the fuel element blank mold are loaded, vacuum-sealed, and isostatically pressed to obtain the spherical fuel element blank. This invention provides convenient material loading, easy demolding, and reusability of the die, and also helps improve the isotropy and molding quality of the spherical fuel element blank.

A thermal bridge 510 is provided between a fuel element 508 and a fuel channel 506 in a high temperature gas cooled nuclear reactor (HTGR) 500 in order to improve thermal transfer between the fuel ele

Embodiments of a nuclear fuel element for use in various types of nuclear reactors are disclosed. One embodiment of the nuclear fuel element comprises a plurality of solid nuclear fuel particles, such as tristructural isotropic fuel particles (TRISO fuel particles), mixed in a non-solid matrix that is essentially stagnant relative to the plurality of solid nuclear fuel particles. The non-solid matrix may comprise a liquid metal, a liquid metal alloy, and a liquid salt. Various embodiments of the non-solid matrix include tin, lead, sodium, aluminum, bismuth, and alloys thereof. A method for producing a nuclear fuel and embodiments of a nuclear fuel core comprising the nuclear fuel element are also disclosed.

A variable diameter fuel rod for a nuclear reactor assembly is disclosed. The nuclear reactor assembly includes an elongated cladding tube configured to accommodate a plurality of fuel pellets including fissile material arranged toward a fuel stack. The elongated cladding tube includes first and second axial reflector regions, a medial axial region therebetween, a cladding outer diameter of the medial axial region defined as d1, a cladding outer diameter of at least one of the first and second axial reflector regions defined as d2, and a transition region located between the second diameter d1 of the medial axial region and a larger diameter d2 of the axial reflector region. The diameter d2 of the axial reflector region is greater than the diameter d1 of the medial axial region.

A plated metal substrate and method of manufacture are provided. The method includes depositing a first layer on at least a portion of the metal substrate using physical vapor deposition to create a coated substrate. The method includes electroplating a second layer comprising chromium, a chromium alloy, or a combination thereof on at least a portion of the first layer to create the plated substrate.

Fuel assembly for a nuclear reactor, of the Na-NFR type, without a casing, comprising a bundle of fuel needles held laterally by perforated grids and longitudinally by stiffening rods passing through the grids. The invention essentially consists of a fuel assembly (1) of hexagonal or parallelepiped cross-section without a hexagonal tube casing, preferably intended for low-power-volume liquid sodium-cooled fast reactors (Na-NFRs). Figure for the abstract: Fig. 5

The present invention relates to a casing comprising a tube (14) extending along a longitudinal axis and a tubular liner (18) contained within the tube (14), wherein the tube (14) comprises at least one reinforcing layer (16) made of a composite material comprising a ceramic matrix reinforced with ceramic reinforcing fibers, and wherein the thickness of the tube (14) is 280 μm to 600 μm.

A nuclear fuel mechanism and an assembly method for the nuclear fuel mechanism. The nuclear fuel mechanism comprises a lower end plug (1) of a fuel rod, a lower nozzle assembly (2), and an adjustment assembly (3). An adjustment member (32) can drive a connecting member (31) to move, causing a debris prevention plate (21) to move horizontally relative to a nozzle body (22). In this case, the central axis of a constraint through hole (211) in the debris prevention plate (21) is misaligned with the central axis of a constraint counterbore (221) in the nozzle body (22), such that a limiting portion (12) of the lower end plug (1) of the fuel rod is restricted below the debris prevention plate (21). By means of restricting the limiting portion (12) of the lower end plug (1) of the fuel rod between the debris prevention plate (21) and the nozzle body (22), the axial movement of the fuel rod is limited. When the clamping force of a spacer grid is lost, it is ensured that the fuel rod does not move axially under a hydraulic lifting force or when a fuel assembly is subjected to an axial impact load, thereby avoiding exacerbating fretting wear between the grid and the fuel rod, and preventing failure of the fuel rod caused by the fuel rod falling and impacting the lower nozzle assembly (2).

A fuel assembly (100) for a nuclear fission reactor (10). The fuel assembly (100) is centred on a longitudinal axis (102). The fuel assembly (100) comprises a fuel compact (200) which defines a flow passage (202) running from a flow inlet (204) provided at a first end (206) of the fuel compact (200) to a flow outlet (208) provided at a second end (210) of the fuel compact (200). The flow passage (202) defines an internal surface (222) of the fuel compact (200). A displacer element (300) is provided in the passage (202) and mounted such that a clearance (212) is maintained between the internal surface (222) of the fuel compact (200) and the displacer element (300) to define an annular coolant flow passage (230).

A nuclear fuel, moderator, and absorber (FMA) assembly provides a mechanism to tailor the fissile material density, moderating power, and neutron absorbing functions at each lateral and axial location within the core; maintains the geometry of the materials required for these functions; retains gaseous fission products, solid fission products, and gaseous phases such as hydrogen as necessary. The FMA concept may be used in many different types of reactors to optimize reactor fuel utilization and safety performance. Advanced methods such as genetic algorithms or other methods that are currently available or become available and the use of artificial intelligence may be used to specify the components, materials, or features of each individual FMA for optimization of reactor core loading that results in superior reactor safety and economic performance. The Fuel Moderator and Absorber (FMA) assembly may be configured to enhance the retention of fission products, allowing siting of nuclear reactors with a minimal Emergency Planning Zone.

Embodiments of the present application relate to the technical field of spent fuel reprocessing, and particularly to a method for measuring displacement of fuel rod inner pellets when fuel assembly is sheared, comprising: providing a plurality of force measuring connectors and a plurality of force measuring devices; arranging the force measuring connectors in a part of the gas cavity of the fuel rod, and connecting one end of the force measuring connectors with the fuel pellets; connecting the plurality of force measuring devices with the plurality of force measuring connectors one by one at the end of the shell close to the gas cavity, and contacting the other end of the force measuring connectors with the force measuring devices; when the fuel assembly is sheared, the axial displacement force towards the gas cavity is generated due to the extrusion of the fuel pellets, the force measuring connectors transmit the displacement force to the force measuring devices, and the displacement force measured by the force measuring devices is collected and recorded. The measurement method in the embodiments of the present application can measure the displacement force generated by the extrusion of the fuel pellets when the fuel assembly is sheared, so as to modify the shearing process parameters and achieve better shearing effect.

The embodiment of the present application provides a reactor fuel assembly which can be locked in a core support part in a reactor, and the reactor fuel assembly comprises a reactor fuel assembly body, a locking part, a stop part and a locking device; the locking part is fixedly connected with the reactor fuel assembly body through the stop part; wherein the core support part is provided with a through hole, when the reactor fuel assembly is locked in the core support part, the locking part passes through the through hole, the locking device is sleeved on the part of the locking part which passes through the through hole, and the core support part limits the axial movement of the reactor fuel assembly through the locking device and the stop part, so as to lock the reactor fuel assembly in the core support part. The reactor fuel assembly provided by the embodiment of the present application is provided with the locking device, and can ensure that the reactor fuel assembly is detachably installed in the reactor while preventing the reactor fuel assembly from floating up.

A fuel element with an ordered particle fuel particle packing to improve lifetime and retention. The fuel element includes an encapsulation matrix and a plurality of coolant channels formed in the encapsulation matrix. Fuel element further includes a plurality of fuel particle matrices disposed within the encapsulation matrix. Each of the fuel particle matrices is ordered in a vertically aligned geometry or a twisted geometry to: (a) substantially laterally surround a contour of a respective coolant channel, and (b) orient substantially longitudinally or substantially helically along the respective coolant channel. For example, each of the fuel particle matrices can include a plurality of fuel particles that are a cluster around the respective coolant channel. The encapsulation matrix can be a high-temperature matrix. A fabrication method for the fuel element includes three-dimensional printing the fuel element and placing the plurality of fuel particles in selected locations in the fuel element.

This invention belongs to the field of nuclear reactor core design, specifically relating to a method for constructing an equivalent model of the non-fuel region of a fast neutron reactor with complex geometry. First, the core of the three-dimensional fast neutron reactor to be simulated is geometrically divided into several layers along the axial direction. For each layer, a fine-group embedding self-screen resonance model is established. Then, the material of all fuel regions in the core is homogenized and used as average fuel. This average fuel is constructed outside the cylindrical model of the non-fuel region, ensuring that the non-fuel nuclides calculated by the cylindrical model are consistent. n The escape cross section is conserved with the escape cross section calculated by resonance, and an equivalent model of the outermost fuel radius is iteratively searched. Its advantages are: this method can quickly and online obtain the equivalent model of each non-fuel zone in the reactor core; it offers excellent geometric flexibility for complex reactor cores, fully considers environmental effects, and has higher computational accuracy; it can be used for rapid simulation calculations of numerical reactors and engineering applications.

Device for reducing spent nuclear fuel, comprising a container for receiving nuclear fuel, wherein the device is configured to transmute long-lived radioisotopes of the nuclear fuel into radioisotopes having a significantly shorter half-life than the initial radioisotopes by interaction with fast neutrons.

In high-temperature gas reactor fuel, this enables the core's power density while maintaining the core's criticality conditions. [Solution] According to the embodiment, the nuclear fuel assembly 100 for a high-temperature gas reactor comprises a plurality of fuel sections 110 having a columnar matrix extending in the axial direction and a plurality of coated fuel particles containing nuclear fuel material dispersed within the matrix, and a coolant flow path 12 formed to extend in the axial direction between each adjacent fuel section 110 among the plurality of fuel sections 110, for passing a coolant. The flow path volume ratio, which is the ratio of the sum of the volumes of each of the plurality of coolant flow paths 120 to the volume of the nuclear fuel assembly 100 for a high-temperature gas reactor, is 10% or more and 50% or less, and the fuel particle filling rate, which is the ratio of the volume of coated fuel particles to the sum of the volume of the matrix and the volume of the coated fuel particles, is above a predetermined boundary value and 60% or less.

Device which is configured to hold a nuclear fuel and has one or more neutron sources which are configured to emit free neutrons which can interact with isotopes of the nuclear fuel, wherein the one or more neutron sources are configured such that the neutron flux strength of the generated neutrons is more than 10 12 neutrons per second and the one or more neutron sources have a power supply by means of which the neutron flux strength can be controlled.