42 results about "Spent nuclear fuel" patented technology

An apparatus for installing and removing a fixing device for handling a spent nuclear fuel assembly is disclosed. The apparatus for installing and removing a fixing device for handling a spent nuclear fuel assembly is an apparatus for installing or removing the fixing device, provided between an upper fixture and a guide pipe constituting a nuclear fuel assembly, to or from the spent nuclear fuel assembly, and comprises: a rod part including a rotating rod with one end detachably connected to the fixing device, and at least one cover rod in which the rotating rod is positioned; and an operation part connected to the rod part so as to vertically move or rotatably operate the rotating rod and the cover rod.

A rare-earth-doped aluminum-based composite material for shielding spent nuclear fuel comprises, by weight percentage: gadolinium oxide 1 wt.%–10 wt.%, europium oxide 1 wt.%–10 wt.%, samarium oxide 1 wt.%–10 wt.%, dysprosium oxide 1 wt.%–10 wt.%, erbium oxide 1 wt.%–10 wt.%, with the remainder being 6063 aluminum alloy powder. This invention exhibits excellent neutron absorption capacity. The aluminum-based material maintains both low weight and high strength and ductility. Furthermore, the addition of rare-earth elements such as Gd, Eu, and Sm, which have high thermal neutron absorption cross-sections, significantly enhances the material's neutron absorption capacity. The introduction of rare-earth elements such as Gd, which react with neutrons in an (n,γ) reaction, effectively prevents the formation of numerous helium bubbles in the matrix, thus improving the material's practical service life.

Provided is a radiation decomposition device and a radiation decomposition method that allow efficient decomposition of an irradiated substance while reducing the size of equipment as much as possible. A radiation decomposition device (100) according to the present invention is characterized by including: a radiation source (101) that emits radiation released from a sealed radioactive substance; a reaction tank (103) that contains a to-be-irradiated substance (104); and a heat transfer tank (102) that covers the radiation source (101) and transfers, to the reaction tank (103), heat generated by the decay of the radioactive substance. It is preferable that the radiation source (101) is: a radiation source formed of spent nuclear fuel or vitrified waste containing fission products extracted from spent nuclear fuel; a radiation source containing fission products extracted from spent nuclear fuel; a radiation source containing Co-60; a radiation source containing Cs-137; or a high-level radioactive waste liquid.

The application belongs to the technical field of separation and extraction, and particularly relates to a 8C-DAPhen ligand, a preparation method and application thereof. The method is developed from the design of a ligand molecular structure, and a novel cyclic DAPhen ligand is developed through specific structure design. The ligand has a separation factor (SF Eu / Am ) of more than 600 for lanthanide and actinide elements, and exhibits excellent separation performance. The application provides a new perspective for in-depth understanding of lanthanide and actinide separation mechanism, and provides technical support for establishing an advanced spent nuclear fuel reprocessing system and realizing efficient utilization of minor actinide elements.

The present disclosure relates to nuclear chemical, particularly radiochemical, technologies at different stages of the nuclear fuel cycle, such as the production of purified nuclear materials (uranium, zirconium) or the reprocessing of spent nuclear fuel from nuclear power stations, in which extraction processes and operations for purifying nuclear materials are used. An example method, which includes the partial decomposition of nitric acid during continuous evaporation while a solution containing a reducing agent is fed into the bottom part of an evaporator having a circulating bottoms solution, consists in that the process is carried out such that the solution is kept in the bottom part of the evaporator for more than 2 hours under the addition of an aqueous solution of formaldehyde and formic acid (hereinafter “the mixture”) or a solution of formic acid after the process has been started using the mixture.

Nuclear waste, such as, but not limited to, spent nuclear fuel (SNF) assemblies or portions thereof, are placed within diecast molds, and then gravity fed molding occurs within those loaded diecast molds and around the SNF assemblies (or portions thereof) that are located within those diecast molds, using molten alloy(s) for filling the diecast molds, to form solid metal ingots upon sufficient cooling of the newly formed ingots. The molten alloy(s) may contain a copper alloy. The molten alloy(s) may also contain neutron absorbers and / or helium immobilizing materials. Each such formed ingot may entirely encapsulate a SNF assembly (or a portion thereof) within the resolidified alloy(s). The ingots may be formed into waste capsules. The ingots and / or the waste capsules may be landed in deeply located horizontal wellbores. The deeply located horizontal wellbores may be at least partially located within deeply located geologic formations.

The invention relates to the field of nuclear technologies, in particular to an oxide-based uranium-plutonium nuclear fuel for an atomic power station with thermal neutron reactors. The technical result of the invention is the development of a REMIX-type fuel composition formulation making it possible, in the nuclear fuel cycle, to involve fissile nuclear materials regenerated from spent nuclear fuel with the simultaneous use of enriched natural uranium, and also moreover providing a solution to the problems of separately using previously isolated plutonium (including weapons-grade plutonium), of reducing the quantity of spent nuclear fuel by recycling fissile materials from spent nuclear fuel during the lifespan of a nuclear reactor (up to 5 recyclings), of economizing on natural uranium for manufacturing fuel and, as a result, of making the nuclear fuel cycle self-sustainable. The invention makes it possible to use REMIX fuel for solving an entire range of problems which a closed nuclear fuel cycle may face, taking into account the number of reactors, availability of natural uranium and the amount of stored spent nuclear fuel.

As one way of preparing for global cooling, we will provide a nuclear reactor that requires less investment capital, is based on the premise that population density will decrease due to population decline, and it is unknown when, where, and what scale an earthquake will occur, and of course does not require a final disposal site, and can convince the media and local residents by reducing the amount of spent nuclear fuel from light water reactors. [Solution] A nuclear reactor in which a large number of allowable alloy-containing nuclear fuel rod assemblies 1, each consisting of a large number of allowable alloy-containing nuclear fuel rods made of heavy noble gas coolant and allowable enrichment plutonium alloy, are arranged in a square lattice pattern in the core of an existing BWR.

A radioactive nuclear waste storage system includes a cask comprising a hermetically sealed internal cavity configured for holding the waste such as spent nuclear fuel submerged in an inventory of water. One or more pressure surge capacitors disposed inside the cask include a vacuum cavity evacuated to sub-atmospheric conditions prior to storage of fuel in the cask. At least one rupture disk seals a vacuum chamber inside each capacitor. Each rupture disk is designed and constructed to burst at a predetermined burst pressure level occurring inside the cask external to the capacitor. This allows excess cask pressure occurring during a high pressure excursion resulting from abnormal operating conditions to bleed into capacitor, thereby returning the pressure inside the cask to acceptable levels. In one embodiment, the capacitors are located in peripheral regions of the cask cavity adjacent to the circumferential wall of the cask body.

A method of handling spent nuclear fuel assemblies immerses the spent nuclear fuel assemblies in water in a relatively short time period when compared to traditional methods. A spent nuclear fuel assembly is removed from a nuclear reactor, an inert gas is applied to the fuel assembly, moisture content in the inert gas is gradually increased as it is applied to the fuel assembly, and the fuel assembly is immersed in water. The fuel assembly is immersed relatively quickly, within about 2 hours or less, which improves safety and allows normal processing and handling equipment to care for the fuel assembly. The fuel assembly may then be loaded into a cask for long-term storage and / or disposal.

The present invention relates to a drying system for a canister loaded with spent nuclear fuel, the purpose of which is to rapidly dry the interior of the canister to meet required requirements while simultaneously verifying the drying state in real time, and to detect the radiation dose rate for water and air during the execution of the drainage and depressurization drying process, and to determine whether the spent nuclear fuel cladding is damaged by performing radionuclide analysis on water samples and air samples when a preset radiation dose rate is detected. The configuration comprises: an air distribution device having first to fifth connectors and a pressure gauge mounting hole (20f), which serves as a distribution means for controlling the air flow path, wherein the first connector is detachably connected to the exhaust port of the canister so as to be connected to the inner hollow of the canister; and first to fifth solenoid valves each mounted on the first to fifth connectors of the air distribution device and opening and closing the first to fifth connectors. A pressure sensing means mounted in a pressure gauge mounting hole of the air distribution device to detect the internal pressure of the canister and transmit the pressure sensing value; a non-reactive gas supply tank having an exhaust port in which non-reactive gas is stored, connected in communication with the second connector of the air distribution device through a gas supply pipe, and supplying and stopping the supply of non-reactive gas into the canister through the air distribution device according to the opening and closing operation of the second solenoid valve so that non-reactive gas is filled into the empty space where water in the canister is drained; a radionuclide analysis device equipped with a sample analysis chamber in which a collected sample is filled and a radionuclide analysis unit for analyzing radionuclides among the sample in the sample analysis chamber, and for analyzing radionuclides in the collected air and water samples among the air and water discharged from the exhaust port and drain port of the canister; and a primary pressure reduction exhaust pipe connected in communication with the third connector of the air distribution device and exhausting the air in the canister to the exhaust system; A sixth solenoid valve mounted on the exhaust system-side end of the primary pressure reducing exhaust pipe and opening and closing the exhaust system-side end of the primary pressure reducing exhaust pipe;A primary pressure reducing pump mounted on the primary pressure reducing exhaust pipe between the third and sixth solenoid valves and pumping air inside the canister to be exhausted into the exhaust system through the primary pressure reducing exhaust pipe; a first radiation dose rate detection means mounted on the primary pressure reducing exhaust pipe between the third solenoid valve and the primary pressure reducing pump and detecting the radiation dose rate of the air exhausted into the exhaust system along the primary pressure reducing exhaust pipe in real time and transmitting the detected value; a first air sample collection tube branched to communicate with the primary pressure reducing exhaust pipe between the sixth solenoid valve and the primary pressure reducing pump, connected to communicate with the inlet of the sample analysis chamber of the radionuclide analyzer, and supplying an air sample collected from the primary pressure reducing exhaust pipe into the sample analysis chamber of the radionuclide analyzer; and a seventh solenoid valve mounted on the first air sample collection tube and opening and closing the first air sample collection tube; A secondary pressure reducing exhaust pipe connected to communicate with the fourth connector of the air distributor device and exhausting air inside the canister into the exhaust system; an eighth solenoid valve mounted on the exhaust system-side end of the secondary pressure reducing exhaust pipe and opening and closing the exhaust system-side end of the primary pressure reducing exhaust pipe; a secondary pressure reducing pump mounted on the secondary pressure reducing exhaust pipe between the fourth and eighth solenoid valves and pumping air inside the canister to be exhausted into the exhaust system through the secondary pressure reducing exhaust pipe; and a second radiation dose rate detection means mounted on the secondary pressure reducing exhaust pipe between the fourth solenoid valve and the secondary pressure reducing pump, detecting the radiation dose rate of the air exhausted into the exhaust system along the secondary pressure reducing exhaust pipe in real time and transmitting the detected value; A second air sample collection tube that branches off to communicate with the secondary pressure exhaust pipe between the eighth solenoid valve and the secondary pressure pump, is connected to communicate with the inlet of the sample analysis chamber of the radionuclide analyzer, and supplies an air sample collected from the secondary pressure exhaust pipe into the sample analysis chamber of the radionuclide analyzer;A ninth solenoid valve mounted on the second air sample collection tube and opening and closing the second air sample collection tube; a drain pipe detachably connected to the drain port of a canister and draining water filled in the canister into a drainage system; tenth and eleventh solenoid valves each mounted on both ends of the drain pipe and opening and closing both ends of the drain pipe; a drain pump mounted on the drain pipe between the tenth and eleventh solenoid valves and pumping and draining water filled in the canister; a third radiation dose rate detection means mounted on the drain pipe between the tenth solenoid valve and the drain pump, detecting the radiation dose rate of the water drained along the drain pipe in real time and transmitting the detected value; and a water sample collection tube branched out to communicate with the drain pipe between the eleventh solenoid valve and the drain pump, connected to communicate with the inlet of the sample analysis chamber of the radionuclide analyzer, and supplying a water sample collected from the drain pipe into the sample analysis chamber of the radionuclide analyzer. A 12th solenoid valve mounted on the water sample collection tube and opening and closing the water sample collection tube; a wash water supply tank having a drain port in which wash water is stored, which supplies wash water into the primary and secondary pressure reduction exhaust pipes and the drain port to perform washing; a first wash water supply pipe branched to communicate from the drain port between the 10th solenoid valve and the third radiation dose rate detection means, and connected to communicate with the drain port of the wash water supply tank to supply wash water into the drain port; a 13th solenoid valve mounted on the first wash water supply pipe and opening and closing the first wash water supply pipe; and a wash water supply pump mounted on the first wash water supply pipe between the wash water supply tank and the 13th solenoid valve and pumping wash water within the wash water supply tank; A second washing water supply pipe that is branched out to communicate from the first washing water supply pipe between the washing water supply pump and the 13th solenoid valve, and is connected to communicate with the 5th connector of the air distribution device (20) to supply washing water into the first and second pressure reduction exhaust pipes;The system is characterized by comprising: a control unit that is respectively connected to the pressure sensing means, the first to third radiation dose rate detection means, the radionuclide analysis device, the first and second pressure reducing pumps, the drainage pump, the wash water supply pump, and the first to thirteenth solenoid valves, and controls the operation of the first and second pressure reducing pumps, the drainage pump, the wash water supply pump, and the first to thirteenth solenoid valves based on data received from the pressure sensing means, the first to third radiation dose rate detection means, and the radionuclide analysis device, and operation commands received from the pressure sensing means; and a control panel that is equipped with a display unit for displaying received information, an input unit for inputting operator commands, and an operation status display unit for outputting the system's operation status visually and audibly, and is connected to the control unit to display various information transmitted from the control unit on the display unit, output normal, abnormal, and emergency statuses during system operation to the operation status display unit, and transmit the operator's operation commands to the control unit through the input unit.

An integrated system for recycling used nuclear fuel (UNF) emerging from a reactor has a decladding vessel separating fuel pellets from nuclear fuel rods via oxidation to produce a uranium compound. A

To perform nuclear combustion of accumulated light-water reactor spent nuclear fuel and depleted uranium.SOLUTION: A nuclear fuel is taken out from an unused nuclear fuel rod assembly, metallized, and cooled with heavy rare gas.EFFECT: Energy for a long period can be secured from accumulated light-water reactor spent nuclear fuel.SELECTED DRAWING: Figure 1

A nuclear fuel storage system comprises a fuel rack immersible in a fuel pool which comprises a baseplate and a cellular body extending from the baseplate. The body comprises plural cell walls arranged to define an array of upwardly open cells each configured to store a nuclear fuel assembly therein. A raised fuel assembly support ring may be disposed at the bottom of each cell on the baseplate to engage and support a fuel assembly. A neutron absorber insert disposed in at least one cell comprises a bottom end configured to frictionally engage the support ring to secure the neutron absorber insert therein. The absorber insert comprises resiliently deformable radial locking protrusions which frictionally engage an outward facing annular side surface of the support ring in one embodiment. The absorber insert may be retrofit into existing racks to restore reactivity control.

Disclosed is a neutron-absorbing composite material. The neutron-absorbing composite material comprises: an aluminum substrate; and reinforcing material powder dispersed in the aluminum substrate and having a boron carbide core and a gadolinium oxide shell covering the surface of the boron carbide core.

A high-quality tomographic image acquisition device for a densely arranged spent nuclear fuel according to an embodiment of the present inventive concept relates to an gamma emission tomography device for detecting radiation of a fuel assembly which receives a plurality of fuel rods and may comprise: a first detection part disposed on one side of the fuel assembly and detecting radiation emitted from the fuel assembly; and a second detection part including a rod-shaped sealing part disposed inside the fuel assembly and a detection member disposed inside the sealing part and detecting radiation emitted from the fuel assembly.

The present invention relates to a spent nuclear fuel storage container structured to reduce internal pressure, the storage container having at least one recess formed on the outer surface of a canister in which at least one spent nuclear fuel assembly is accommodated, and a support coupled to the inner surface of a cask, in which the canister is accommodated, and inserted in the recess, thereby reducing the internal pressure of the storage container.

Proposed is a cutting apparatus for a fuel basket accommodating spent nuclear fuel of a heavy water reactor, wherein the apparatus includes a base, a vertical support arranged on one side of the base; a turn table arranged to be reciprocated between one side and an opposite side of the base and be horizontally rotatable on the base; a horizontal support arranged to extend from an upper-end of the vertical support in a horizontal direction toward the turn table; a side-cutting means arranged on the vertical support protruding toward the turn table for cutting a side welding bead of the fuel basket mounted on the turn table; and an upper-cutting means arranged on the horizontal support protruding toward the turn table for cutting an upper welding bead of the fuel basket mounted on the turn table.

To provide a nuclear reactor that is decreasing light water reactor spent nuclear fuel to persuade the media of mass communication and local residents, not to mention no need for a final disposal site, on the premise that inhabitants are decreasing and the population density is small and that it is unknown when and where what scale of earthquake takes place.SOLUTION: The breeding performance is enhanced with heavy gas cooling material and nuclear fuel low in plutonium enrichment, and the nuclear fuel is burnt to enhance the plutonium enrichment of the nuclear fuel. Simple processing of only removing fission products from the used nuclear fuel is only required. Although even photovoltaic power generation facilities exploded, dumped objects will increase in future when the power selling price decreases to 8 yen / kwh under a trade guidance (Chinese products may be used as fences in EU and as sunshades in Japan.). The nuclear reactor may take advantages thereof.SELECTED DRAWING: Figure 1

The application belongs to the technical field of extraction separation, and particularly relates to an OE-DAPhen ligand, a preparation method and application thereof. The application develops a novel DAPhen ligand through specific structure design from the design of a ligand molecular structure. The separation factor (SF) of the OE-DAPhen ligand for lanthanide and actinide elements is more than 400, and the OE-DAPhen ligand exhibits excellent separation performance. The application provides a new perspective for in-depth understanding of lanthanide and actinide separation mechanism, and provides technical support for establishing an advanced spent nuclear fuel reprocessing system and realizing efficient utilization of minor actinide elements. Eu / Am ).

The present application relates to a kind of volatile fission product trapping device and trapping method generated in spent fuel dry reprocessing, the device includes catalytic reaction device, dryer 1, fixed bed adsorption device 1, liquid adsorption device, dryer 2 and fixed bed adsorption device 2, by simulating effluent including radioactive tritium, carbon 14, iodine 129 and inert gas Kr and Xe, respectively with non-radioactive hydrogen, carbon dioxide, methyl iodine, Kr and Xe mixed gas as simulation gas source, by each component to each substance in mixed gas is classified and coordinated absorption, finally reach the index that the adsorption trapping efficiency of each effluent simulation is not less than 90%, by simulation can realize the high-efficiency adsorption trapping of the volatile radioactive effluent generated in spent nuclear fuel reprocessing process by the device of the present application.

A fuel rack for wet storage of nuclear fuel in a fuel pool comprises, in one embodiment, a base plate and a cellular body formed from slotted plates bonded to each other and stacked, coupled to the base plate. This cellular body comprises densely packed, upward-opening cells, each holding a nuclear fuel assembly. When the rack is submerged in water, open flax straps are formed between at least some of the water-filled cells, acting as neutron moderators to control the reactivity within the rack. In one embodiment, flax straps are interspersed between adjacent cells in a first direction along a first horizontal axis of the rack. However, flax straps are not interspersed between adjacent cells in a second direction perpendicular to a second horizontal axis. Other flax strap and cell arrangements are also provided. Tension elements penetrate some of the flax straps, and these tension elements compress the stack of plates to ensure stability.

Manufacturing process of a cask for a storage of spent nuclear fuel and / or other nuclear waste, during which at least two parts of the cask body comprising at least a cylindrical shell part (2) of the cask body and a bottom part (3) of the cask body with a round bottom are created separately and, after that, the cask is created by welding these parts of the body together. The cylindrical shell part (2) is placed in a positioning device to be rotated around its central axis and, after that cladding beads of a corrosion-resistant CrNi material with a highly basic agglomerated flux are laid onto its inner surface by means of an electroslag welding method. The bottom part (3) of the cask body comprising at least a round bottom (4) of the cask (1) is placed in the positioning device for laying cladding beads by means of the electroslag welding method onto this round bottom (4), the cladding beads are laid onto the round bottom (4) by an electroslag welding using a corrosion-resistant OrNi material with a highly basic agglomerated flux. Cask manufactured according to the process comprises a cylindrical shell part (2) and a bottom part (3) which define a storage space, wherein an inner surface (5) of the cylindrical shell part (2) and of the bottom part (3) is provided with an electroslag cladding from at least one strip-type corrosion-resistant CrNi material and highly basic agglomerated flux.

Disclosed herein is a system comprising: (a) an experimentation cask having a receiving compartment defining an internal portion of the experimentation cask, wherein the receiving compartment is configured to receive a canister, wherein the canister is a vertical and / or horizontal spent fuel storage canister, (b) one or more sensing devices configured to non-destructively evaluate an internal and / or external state of the canister; wherein the one or more sensing devices are positioned within at least a portion of the internal portion of the experimentation cask, or at least a portion of an external portion of the experimentation cask; and wherein the experimentation cask provides radiation- and heat shielded. Also disclosed herein are methods for inspection of an internal and external integrity of the canister using the systems disclosed herein.

Underground nuclear installation (10), comprising: - a vertical shaft (12) having, at a lower end, a bottom (12c) and, at an upper end, an opening (12b), - at least one reactor building (26) housed in the shaft, - and which contains at least one nuclear reactor containment building (30) enclosed within said at least one reactor building (26), and / or at least one spent nuclear fuel pool housed in the shaft, - at least one protective slab (20) against external hazards which seals the opening (12b) of the shaft, extending in particular above said at least one reactor building, - one or more pieces of equipment or buildings (b1-b4) arranged on said at least one protective slab (20). Figure for the abbreviation: Fig. 3.

A nuclear waste-capsule may include: an outer shell; an inner tube, located in that outer shell; and one or more spent nuclear fuel (SNF) assemblies (or portions thereof), with particular structure(s) attached thereto, within that inner tube. The particular structure(s) may be one or more spring-loaded receptacles (SLRs), such that each of the one or more SNF assemblies (or portions thereof), within the given inner tube, may have circumferentially attached thereto at least one SLR. Each such SLR may act as shock absorbing suspension means and may structurally support and centralize its associated SNF assembly (or portion thereof) within the given inner tube. Additionally, the one or more SNF assemblies (or portions thereof), along with the associated SLRs, may be immersed within a protective / preventative medium, within the given inner tube. The so loaded waste-capsule may be deposited within a wellbore that is located within a repository geological formation.

Nuclear waste, such as, but not limited to, spent nuclear fuel (SNF) assemblies (or portions thereof), are placed within diecast molds, and then gravity fed molding occurs within those loaded diecast molds and around and in the emplaced SNF assemblies (or portions thereof) that are located within those diecast molds, using molten alloy(s) for filling the diecast molds, to form solid metal castings upon sufficient cooling after the gravity fed operations. The molten alloy(s) may contain a copper alloy. The molten alloy(s) may also contain neutron absorbers. After the casting is formed, the casting is not separated from its diecast mold, as the diecasting mold and it's casting now form an integral unit. The integral units may be converted into waste capsules. The waste capsules may be landed in deeply located horizontal wellbores. The deeply located horizontal wellbores may be at least partially located within deeply located geologic formations.

The present invention relates to the field of nuclear chemistry, in particular radiochemistry, technologies for different stages of the nuclear fuel cycle, such as production of purified nuclear materials (uranium, zirconium) or reprocessing of spent nuclear fuel from nuclear power plants, where extraction processes and operations are used for purification of nuclear materials. The essence of the method, which includes partial decomposition of nitric acid during continuous evaporation while feeding a solution containing a reducing agent to the bottom part of an evaporator with a circulating bottom solution, lies in conducting the process so that after starting the process with an aqueous solution of formaldehyde and formic acid (hereinafter referred to as "mixture"), the solution remains in the bottom part of the evaporator for more than 2 hours with addition of the mixture or a solution of formic acid. This makes it possible to select a scenario where during evaporation of a model highly active raffinate at a given concentration level (specific volume of the bottom solution does not exceed 0.4 m 3 / ton of radioactive waste), barium nitrate does not precipitate and nitrous oxide is not released. In addition, due to a significant decrease (up to one tenth) in the formaldehyde concentration in the reducing agent and the possibility of continuing the process with a formic acid solution in the complete absence of formaldehyde, the fire and explosion safety of the process increases.

A radiation shielding cask apparatus that comprises a cask body, a bottom lid, and a plurality of canister support elements. The cask body defines a cavity configured to receive a canister containing spent nuclear fuel. The bottom lid detachably coupled to the cask body to enclose a bottom end of the cavity. The plurality of canister support elements coupled to a bottom portion of the cask body and alterable between: (1) a canister support state in which the canister support elements protrude into the cavity, support the canister, and prohibit the canister from being removed from the cavity via the bottom end of the cavity; and (2) a canister unloading state in which the canister support elements are retracted and allow the canister to be removed from the cavity via the bottom end of the cavity when the bottom lid is removed from the cask body.

The present invention relates to the field of nuclear technology, in particular to uranium-plutonium oxide nuclear fuel for nuclear power plants with thermal neutron reactors. The technical result of the present invention is the development of a REMIX-type fuel component that allows nuclear fissionable material recovered from spent nuclear fuel to enter the nuclear fuel cycle and simultaneously use enriched natural uranium, as well as ensuring that the problem of handling previously separated plutonium (including weapon-grade plutonium) is solved. By recycling the fissionable material in spent nuclear fuel during the life of a nuclear reactor, the amount of spent nuclear fuel is reduced (up to 5 times), natural uranium used for fuel manufacturing is saved, and thus the self-sufficiency of the nuclear fuel cycle is ensured. The present invention makes it possible to use REMIX-fuel to solve all the problems that may arise in a closed nuclear fuel cycle, while taking into account the number of reactors, the availability of natural uranium, and the accumulated amount of spent nuclear fuel.