Advantages in the nuclear fuel

06.03.2025

Advantages in the nuclear fuel

Figovsky Oleg

Uranium is an abundant metal and is full of energy: One uranium fuel pellet creates as much energy as one ton of coal, 149 gallons of oil or 17,000 cubic feet of natural gas. It does not come out of the ground ready to go into a reactor, though. It is mined and processed to create nuclear fuel. Before uranium goes into a reactor, it must undergo four major processing steps to take it from its raw state to usable nuclear fuel: mining and milling, conversion, enrichment and fuel fabrication. First, uranium is mined with conventional methods or by in-situ leach mining, where carbonated water is shot into underground deposits and piped up to the surface. The worldwide supply of uranium is diverse, coming primarily from Kazakhstan, Canada and Australia. In the United States, uranium is mined in several western states. To sustain the chain reaction necessary to run a reactor, the uranium will need a high enough concentration of a specific isotope, uranium-235. Natural uranium is converted into several different forms to prepare it for enrichment. Special facilities enrich the uranium so that it can be used in a nuclear reactor.

The major commercial fuel enrichment facilities are in the United States, France, Germany, the Netherlands, the United Kingdom and Russia. The enriched uranium is converted again into a powder and then pressed into fuel pellets. The fuel fabricator loads these pellets into sets of closed metal tubes called fuel assemblies, which are used in nuclear reactors. More than 10,000 results found in the Worldwide database for nuclear fuel. Below I describe only last year patents.

US2025062043 (A1) - A NUCLEAR FUEL ROD CLADDING TUBE AND A METHOD FOR MANUFACTURING A NUCLEAR FUEL ROD CLADDING TUBE

A nuclear fuel rod cladding tube is described. The nuclear fuel cladding tube has an manufacturing a nuclear fuel rod cladding tube is also described.

US2025062044 (A1) - NUCLEAR MATERIAL AND METHODS

Methods of providing load following capability to commercial nuclear reactors. Materials that thwart nuclear reactor hotspots and transients by absorbing excess neutrons such as hard or high energy neutrons. Nuclear fuel additives to stabilize nuclear reactor transients. Materials that interact more strongly with high energy neutrons than they do with now energy or thermal neutrons.

PH12021553225 (A1) - METHOD FOR MANUFACTURING A NUCLEAR REACTOR FUEL ASSEMBLY

The invention relates to nuclear energy and can find application in enterprises involved in manufacturing fuel assemblies, primarily for water-cooled nuclear energy reactors and nuclear energy reactors with a liquid-metal coolant. The essence of the invention: in a method for assembling fuel elements into fuel assemblies which includes the following operations of manufacturing and monitoring fuel elements, applying a protective coating to each fuel element, assembling the prepared fuel elements into a fuel assembly, attaching a head section and a tail section, washing off the protective coating and drying, the operations of applying the protective coating and assembling the fuel elements into the fuel assembly are combined, using as the protective coating a water-soluble lubricant which contains oxyethylated alkylphenol and monobasic unsaturated fatty acids and which is applied to the surface of the fuel element on the assembly stand during the operation of assembling the fuel elements into the fuel element assembly, the fuel element being transferred in a horizontal direction along its own axis into spacer grid cells through a device for applying the protective coating which is installed on the assembly stand. The operation of washing off the protective coating is carried out using streams of pressurized, room-temperature water.

WO2025028762 (A1) - DRY STORAGE MODULE FOR SPENT NUCLEAR FUEL OF VERTICAL LIGHT WATER REACTOR, WITH IMPROVED AIR OUTLET POSITION AND CYLINDER BODY MOUNTING METHOD, AND STORAGE SYSTEM COMPRISING SAME

The present invention relates to a dry storage module for the spent nuclear fuel of a vertical light water reactor, and to a dry storage module with an improved air outlet and cylinder body mounting method, and a system comprising same, the module comprising: a case for forming a hexahedral accommodation space; a plurality of storage parts, which are arranged in two rows in the accommodation space, store the spent nuclear fuel and are elongated; a hexahedral module part for accommodating the storage parts; canisters in which the spent nuclear fuel is loaded; cylinder bodies each encompassing the canister; cylinder supports for attaching/detaching the cylinder body to/from the module part; an air inlet positioned at a side of the upper portion of the case; an air outlet positioned in the lower portion of the case; and shielding grids disposed in each of the inlet and the outlet.

KR20250011255 (A) - NUCLEAR FUEL ASSEMBLY

A fuel assembly for use in a core of a nuclear power reactor. The assembly includes a frame shaped and configured to fit within the nuclear reactor internal core structure; and a plurality of helically twisted fuel elements supported by the frame in a fuel rod bundle. Each of the fuel elements includes fissile material. When viewed in a cross-section that is perpendicular to an axial direction of the fuel assembly, the outermost fuel elements of the fuel rod bundle define a substantially circular perimeter. Other features, and a nuclear reactor, are also described.

UA129186 (C2) - METHOD FOR PROTECTING NUCLEAR REACTOR AND CORRESPONDING NUCLEAR REACTOR

The protection method comprises the following steps: - Step (S12): Reconstructing a maximum linear power density released among the rods of the nuclear fuel assemblies of the core; - Step (S14): Calculating the thermomechanical state and the burnup fraction of the rods; - Step (S24): Calculating a mechanical stress or a deformation energy density in the cladding of one of the rods by using the reconstructed maximum linear power density, the calculated thermomechanical states and the calculated burnup fractions, using a metamodel of a thermomechanical code; - Step (S30): Comparing the calculated mechanical stress or the calculated deformation energy density with a respective threshold; - Step (S32): Stopping the nuclear reactor if the calculated mechanical stress or the calculated deformation energy density exceeds the respective threshold.

US2025046483 (A1) - METHOD AND APPARATUS FOR SAFE AND EFFICIENT NUCLEAR POWER GENERATION

A system for nuclear power generation includes an accelerator-driven subcritical reactor that operates using molten-salt fuel. The operation of the reactor can be continuously monitored to ensure subcriticality. The system also includes means for removing volatile radioactive fission products from the molten-salt fuel continuously during the operation of the reactor to maintain an amount of the volatile radioactive fission products in the reactor below a threshold corresponding to a safety limit for accidental release of radioactive materials. The system can be used for highly efficient nuclear power generation while preventing criticality accidents and accidental releases of radioactive isotopes.

US2025046480 (A1) - Nuclear Fuel Assembly Retrofit for Increasing Reactor Power

A reactor core having improved power output uses an irregular fuel rod spacing that nevertheless retains grid-positioned control rods allowing a retrofitting of the reactor core to existing reactors without substantial modification to the pressure vessel. Generally, the fuel rod placement deviates from a regular grid and the distance between fuel rods varies.

US2025046479 (A1) - METHOD AND MACHINE FOR TESTING A SPACER GRID OF A NUCLEAR FUEL ASSEMBLY

A test method is for testing a spacer grid of a nuclear fuel assembly comprising a bundle of nuclear fuel rods and N spacer grids distributed along the bundle of nuclear fuel rods, where N is a positive integer equal to or greater than four. The method of testing includes providing a test assembly comprising a bundle of test rods shorter than the nuclear fuel rods and three spacer grids distributed along the test rods, generating an impact on the centrally located spacer grid, and measuring and recording at least one impact parameter and/or at least one displacement of said centrally located spacer grid.

US2025037888 (A1) - NUCLEAR POWER PLANT INCLUDING SMALL MODULAR REACTOR (SMR) DISPOSED IN COOLING WATER TANK AND MAINTENANCE METHOD THEREOF

The present invention relates to a nuclear power plant which includes a small modular reactor (SMR), the nuclear power plant comprising a water tank, wherein the water tank comprises: a first water tank filled with cooling water and forming a first space in which spent nuclear fuel is disposed; and a second water tank forming a second space which is separated from the first space and in which the small modular reactor (SMR) is disposed.

US2025037892 (A1) - NUCLEAR WASTE CASK WITH IMPACT PROTECTION, IMPACT AMELIORATION SYSTEM FOR NUCLEAR FUEL STORAGE, UNVENTILATED CASK FOR STORING NUCLEAR WASTE, AND STORAGE AND TRANSPORT CASK FOR NUCLEAR WASTE

A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask overpressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.

US2025029740 (A1) - MANDREL-WOUND, SPLINED MONOLITHIC FUEL ASSEMBLY CORE, FUEL ASSEMBLY AND REACTOR INCORPORATING SAME, AND METHODS OF MANUFACTURE

Insulated fuel assembly core with axially arranged fuel monoliths including channels and having a composition including a fissionable fuel component, exhaust support plate, exhaust shield assembly, and insulation layer. Fuel monoliths have an eccentric cylinder shape or a right circular cylinder shape with side surface keyway. The eccentric shape and/or a keyway (with associated alignment rod) provide alignment. Channels in the exhaust support plate are oriented so propellant gas flowing from the fuel monoliths through the exhaust support plate does not impinge the exhaust shield assembly. Insulated fuel assembly cores are manufactured by forming a tensioned fuel monolith stack mandrel assembly using mandrel spacers and internal tensioning components and mandrel winding an insulation layer on an outer surface of the tensioned fuel monolith stack mandrel assembly. Insulated fuel assembly cores can be incorporated into fuel assemblies of nuclear propulsion fission reactor structures, for example, a nuclear thermal propulsion engine.

US2025029739 (A1) - DEVICE FOR ASSEMBLING AND DISASSEMBLING TOP NOZZLE OF NUCLEAR FUEL ASSEMBLY

Proposed is a device for assembling and disassembling a top nozzle of a nuclear fuel assembly wherein the top nozzle of the nuclear fuel assembly is assembled and disassembled with improved convenience, and the load value is measured to ensure stable operations without damaging components. To this end, the device includes a pedestal including a threaded hole through both sides, a screw bar screw-coupled to the threaded hole to reciprocate in a straight line, a top nozzle plate configured to be detachably coupled to the screw bar and to be able to be hooked by and coupled to the top nozzle of the nuclear fuel assembly, and a load cell provided between the top nozzle plate and the screw bar to measure a load value applied to the top nozzle plate hooked on the top nozzle.

SMT202100412 (T1) - NUCLEAR FUEL PEBBLE AND METHOD OF MANUFACTURING THE SAME

A method of manufacturing nuclear fuel elements may include: forming a graphite base portion of the fuel element; depositing a first layer of fuel, burnable poison and/or breeder particles on the base portion; forming a first graphite layer on the base portion; depositing a second layer of fuel, burnable poison and/or breeder particles on the first graphite layer; forming a second graphite layer on the first graphite layer; and forming a graphite cap portion of the fuel element on the second graphite layer, wherein, adjacent fuel, burnable poison and/or breeder particles of the first layer are spaced apart by substantially the same distance, and adjacent fuel, burnable poison and/or breeder particles of the second layer are spaced apart by substantially the same distance. The fuel element may be a spherical fuel pebble for pebble bed reactors. The fuel particles may be tri-structural-isotropic (TRISO) particles that do not have an overcoat.

US2025022621 (A1) - NUCLEAR FUEL ELEMENT

Disclosed embodiments include fuel assemblies, methods of making a fuel element, and methods of using a fuel element. A fuel element includes fuel, a fuel liner, and a cladding. The liner may be formed of one, two, three, or more layers of different materials, including different alloys have a different primary metallic component. The cladding may likewise be formed of one, two, three, or more layers of different materials. The different materials may include different alloys, different compositions, and/or different alloys in which the primary constituent of the alloy is a different material.

US2025022620 (A1) - Molten Salt Nuclear Reactor of the Fast Neutron Reactor Type, Having a Design of the Primary Circuit Allowing Exploitation which is Versatile in Terms of Fuel and Mode of Operation

A molten salt nuclear reactor of the fast neutron reactor type may be designed as a cylindrical shell in the reactor vessel free of moderator or at the very least of a moderator enabling a reactor to be qualified as a thermal neutron reactor, which may make it possible to effectively separate the fluid zones between those delimited at its periphery in which the heat exchanger(s) exchanging heat between primary and secondary circuit is (are) arranged and the zone inside the shell of which the bottom defines the reactor core within which the nuclear fission chain reactions occur, and a neutron reflector at the periphery of the core makes it possible to use a plurality of types of fuel liquid.

US2025014768 (A1) - SUSPENDED URANIUM DIOXIDE FUEL

A nuclear reactor fuel is provided. The nuclear reactor fuel includes a liquid metal alloy, and uranium dioxide (UO2) particles suspended in the liquid metal alloy. The UO2 particles are enriched with uranium-235 (235U) in an amount of less than 20%. The nuclear reactor fuel has a thermal conductivity greater than a thermal conductivity of sintered UO2 pellets at the same temperature. The liquid metal alloy may be a bismuth-lead-tin (Bi—Pb—Sn)-based alloy and a lead-tin (Pb—Sn)-based alloy. A concentration of the UO2 particles in the liquid metal alloy may be up to 30 wt % or more. The UO2 particles alternatively may be uranium carbide (UC) particles, uranium nitride (UN) particles, or tri-structural isotropic (TRISO) particles. A nuclear reactor is also provided. The nuclear reactor includes a reactor vessel and the nuclear reactor fuel. The nuclear reactor fuel is contained in or circulated through the reactor vessel.

WO2025007856 (A1) - HOLLOW RADIOACTIVE

CONTAINMENT FUEL CONTAINING BURNABLE POISON, PREPARATION METHOD THEREFOR AND USE THEREOF

Provided are a hollow radioactive containment fuel containing a burnable poison, a preparation method therefor and the use thereof. The hollow radioactive containment fuel containing a burnable poison comprises a hollow fuel area and a fuel-free protective layer covering the periphery of the fuel area; the hollow fuel area comprises a matrix, and a fuel element and a burnable poison which are distributed in the matrix, wherein the fuel element is an isotropic coated fuel particle, and the burnable poison is an isotropic coated burnable poison particle. The present invention can realize highly compact and safe radioactive containment of a reactor fuel, ensure that radioactive products, especially fission gas, are not released into the environment accidentally, stably provide a fission site for the core of a miniature nuclear power pile for a long period of time, effectively confine the radioactive fission products inside the fuel, and guarantee the safe and stable operation of a reactor.

US2025006385 (A1) - NUCLEAR REACTOR SYSTEM AND METALLIC COOLANT COMPOSITION

One variation of a system includes: a nuclear reactor; a shield arranged about the nuclear reactor; a metallic coolant; and a set of melt seals. The nuclear reactor includes a pressure vessel and nuclear fuel arranged within a lower region of the pressure vessel. The metallic coolant includes a mixture of metals and is configured to: occupy a liquid state within an operating temperature range; occupy an interstitial volume between the nuclear reactor and the shield; and occupy the lower region of the pressure vessel encompassing the nuclear fuel. The set of melt seals are arranged on the pressure vessel and configured to open to enable transfer of a volume of the metallic coolant from the interstitial volume into the lower region of the pressure vessel in response to temperatures within the pressure vessel exceeding the operating temperature range.

WO2025006190 (A1) - NUCLEAR REACTOR FUEL AND ASSOCIATED SYSTEMS AND METHODS

Disclosed are embodiments of a nuclear fuel element for use in various types of nuclear reactors. One embodiment of the nuclear fuel element comprises a plurality of solid nuclear fuel particles, such as tristructural-isotropic (TRISO) fuel particles, intermixed in a non-solid matrix that is substantially 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 of manufacturing a nuclear fuel and embodiments of a nuclear fuel core comprising the nuclear fuel element are also disclosed.

WO2024262717 (A1) - NUCLEAR FUEL ROD FOR DESIGNING AND MANUFACTURING HEAT-PIPE REACTOR, MODULAR NUCLEAR FUEL ROD-COOLING TUBE INTEGRATED ASSEMBLY COMPRISING COOLING TUBE, AND REACTOR CORE STRUCTURE COMPRISING SAME

A nuclear fuel rod-cooling tube integrated assembly, according to the present invention, comprises: a nuclear fuel rod accommodating nuclear fuel; and a cooling tube having at least a portion formed to surround the circumference of the nuclear fuel rod, and the remaining portion extending to the other side connected to the outside of a reactor to transfer heat generated by nuclear fission inside the nuclear fuel rod to a heat exchanger installed outside the re--actor.

US2024428960 (A1) - FUEL-MODERATOR INVERSION FOR SAFER NUCLEAR REACTORS

A nuclear reactor including a nuclear reactor core. The nuclear reactor core includes a plurality of moderator elements, and an inverted fuel moderator block array of one or more inverted fuel moderator blocks. The one or more inverted fuel moderator blocks include a high-temperature matrix; a plurality of fuel particles embedded inside the high-temperature matrix; and at least one moderator opening for disposition of at least one of the moderator elements therein. The one or more inverted fuel moderator blocks also include at least one coolant passage formed in the high-temperature matrix to flow a coolant. The nuclear reactor can also include a reactivity control system, which can include one or more control drums, one or more control rods, or a combination thereof.

ZA201405612 (B) - SYSTEM FOR STORAGE AND TRANSPORTATION OF SEPNT NUCLEAR FUEL

A concrete storage module is adapted to slideably receive a cylindrical canister assembly therein. II act dissipation fins and a tubular heat shield (96) are disposed within the module to help dissipate heat emitted from the nuclear fuel assemblies stored in the canister assembly is composed of a basket assembly constructed from multi-layer structural plates disposed in cross-cross or egg carton configuration. A single port tool is provided for draining water from the canister and replacing the drain water with make-up gas. The single port tool is mounted in the cover of the canister and is in fluid flow communication with the interior of the canister.

US2024410034 (A1) - CYCLIC AMINE MONOAMIDES FOR EXTRACTING URANIUM(VI) AND PLUTONIUM(IV) AND FOR SEPARATING THEM WITHOUT REDUCING PLUTONIUM(IV)

Uses of cyclic amine monoamides for extracting uranium(VI) and/or plutonium(IV) from an acidic aqueous solution, as well as for totally or partially separating uranium(VI) from plutonium(IV) from an acidic aqueous solution. A method for treating an aqueous solution resulting from the dissolution of spent nuclear fuel in nitric acid to extract, separate and decontaminate uranium(VI) and plutonium(IV) in a single cycle and without resorting to any operation of reducing plutonium(IV), and wherein a cyclic amine monoamide or a mixture of cyclic amine monoamides is used as extractant.

US2024412882 (A1) - CERMET FUEL ELEMENT AND FABRICATION AND APPLICATIONS THEREOF, INCLUDING IN THERMAL PROPULSION REACTOR

(preferably refractory-metal coated HALEU fuel kernels) and an array of axially-oriented coolant flow channels. Formation and lateral positions of coolant flow channels in the fuel meat are controlled during manufacturing by spacer structures that include ceramic fuel particles. In one embodiment, a coating on a sacrificial rod (the rod being subsequently removed) forms the coolant channel and the spacer structures are affixed to the coating; in a second embodiment, a metal tube forms the coolant channel and the spacer structures are affixed to the metal tube. The spacer structures laterally position the coolant channels in spaced-apart relation and are consolidated with the ceramic fuel particles to form CERMET fuel meat of a fuel element, which are subsequently incorporated into fuel assemblies that are distributively arranged in a moderator block within a nuclear fission reactor, in particular for propulsion.

US2024404719 (A1) - SYSTEM AND PROCEDURE FOR INSPECTION OF THE SURFACE OF A NUCLEAR FUEL ROD FOR THE AUTOMATIC DETECTION, LOCATION AND CHARACTERIZATION OF DEFECTS

System and procedure for the inspection of the surface of a nuclear fuel rod for the automatic detection, localization and characterization of defects, comprising a plurality of point cloud acquisition systems and translation means for the nuclear fuel rod; where the system also comprises processing means capable of transforming the point cloud into a height map, locally thresholding for the segmentation of the height map and obtaining the discontinuities in said map, classifying the discontinuities in different geometric shapes to obtain the area, length, width, position and orientation, projecting the defect on the y-axis to obtain its depth and calculating the equivalent function and its second derivative to obtain the points where the depth of the defect is maximum.

Nuclear fuel is at the heart of a nuclear reactor, and the safe and economic behaviour of this fuel is a key factor in the continuing long term development of nuclear power. This was recognised early, with the key issues determining the economic drivers for fuel development summarized, for example, in 1977 in Oak Ridge National Laboratory’s report, “A Survey of Nuclear Fuel Cycle Economics 1970 – 1985” (Prince et al. 1977). It was originally anticipated that there would be a first stage involving pool storage of spent fuel, a second stage where reprocessing would lead to the use of plutonium bearing (MOX) fuels in light water reactors and finally the use of fast breeder reactors. The timescales anticipated are now seen to have been extremely optimistic, and the economics are no longer so clearly driving towards reprocessing and fast reactors. However, the drivers of uranium availability and the costs of enrichment, fuel manufacture and waste management that were identified in 1977 are still valid today, and they have ensured continuous development and improvement in nuclear fuel.

The most important determinant of nuclear power’s future is cost-competitiveness compared with alternatives. Nuclear power plants have a ‘front-loaded’ cost structure, i.e. they are expensive to build and comparatively cheap to operate. There is, therefore, a strong economic incentive to maximise the utilisation of the asset. This means fewer unplanned outages and, for plants with batch reloading, longer operational cycles and shorter outages. The load factor of modern nuclear plants with batch reloading is often over 95%, and two year fuel cycles are becoming common. For plants with on-load refuelling capabilities, maximising utilization of the asset has meant longer fuel dwell (i.e. increasing the total time a fuel element spends in the reactor). For all power plants there is also a need to minimise waste arisings, due to limited on-site storage facilities and the cost of waste removal and treatment.

Because nuclear fuel is the source of the vast majority of the radioactivity produced by a nuclear power plant, it is imperative that the design and manufacture of the fuel is sufficiently robust not only to allow it to operate normally without incident, but also to withstand any transient or accident that could occur in the plant in a manner that can ensure that safety is not compromised. This is ensured through a licensing process that oversees, not only operation, but also that the design and manufacture of nuclear fuel is carried out to extremely high standards, and that design requirements are codified and performance is demonstrated experimentally. Modern nuclear fuel is the result of a huge investment in research, experimental testing and operational experience. Changes are introduced to improve safety or performance margins or perhaps to overcome a design problem.