30 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.

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 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.

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 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.

A passively-cooled spent nuclear fuel pool system comprising a spent nuclear fuel pool having a body of liquid water having a surface level. Spent nuclear fuel is submerged in the body of liquid water. The spent fuel heats the body of liquid water and produces water vapor. A lid covering the spent nuclear fuel pool to form a hermetically sealed vapor space between the surface level of the body of liquid water and the lid. A passive heat exchange sub-system fluidly comprising at least one riser conduit and at least one downcomer conduct is coupled to the vapor space. The passive heat exchange sub-system is configured to move water vapor and condensed water vapor via a thermosiphon flow.

The present invention provides an automatic opening / closing type trolley for remote transfer of spent nuclear fuel in a repackaging facility, which has excellent shielding performance so as to minimize radiation due to radioactive materials and moreover to sufficiently carry out the remote transfer of spent nuclear fuel between respective working places in the repackaging facility, the automatic opening / closing type trolley comprising: a transfer cart which is moved on rails by a plurality of transport wheels driven by a driving means; and a storage shielding can comprising an upper shielding plate which is provided on the upper portion of the transfer cart and includes a docking cover that can be opened / closed to close the upper portion of the transfer cart, a fixed shielding plate and a rotating shielding plate for inserting a canister placed on a canister storage can into the side surface thereof and shielding the canister, and a vertical movement plate which moves the canister in the upward direction so as to be carried into the repackaging facility. Accordingly, convenience of use can be provided and conditions of securing high safety and handling the canister more conveniently can be achieved.

According to the present invention, the neutron absorbing structural material of the present invention exhibits superior strength and ductility to those of the conventional Al-B4C composite-based neutron absorber and exhibit superior ductility, and thus not only has a neutron absorption function but also functions as a neutron absorbing structural material that itself has performance as a structural material. Furthermore, problems, such as poor formability of boron-containing corrosion-resistant steel in a manufacturing process and high brittleness of finished products, are improved and at the same time, a separate support or structural material is not required, thus remarkably improving the efficiency of design and construction of spent nuclear fuel storage facilities and the economic efficiency of construction, and it is possible to design a spent nuclear fuel storage container with a certain volume so as to store a larger amount of spent nuclear fuel therein, thus maximizing usability in a limited space.

The present invention relates to a transport basket for defective spent nuclear fuel of a heavy water reactor and, more particularly, to a transport basket for defective spent nuclear fuel of a heavy water reactor that can reduce the burden of a personnel when handling spent nuclear fuel in a test facility by minimizing a storage space and maximizing a thickness such that only a predetermined amount of spent nuclear fuel for soundness evaluation in the test facility can be transported. To this end, provided is a transport basket for defective spent nuclear fuel of a heavy water reactor, comprising: a basket body having a storage space and an internal support that partitions the storage space; a fuel pocket that is installed on one side of each storage space partitioned through the internal support and is installed so as to be rotatable toward the other side of the storage space, and has a detachable groove open in an upward direction such that a fuel case containing the spent nuclear fuel can be detached therefrom; and a cover that opens and closes the storage space of the basket body and is screwed to the basket body.

Provided is a spent nuclear fuel canister lid cutting system in dry environment which enables to safely transport the canister to which spent nuclear fuel is enclosed; to smoothly and easily lift and take out the canister to the cutting work space; to prevent the cutting work space from being exposed to radiation materials while cutting the canister lid; and to prevent a cover of a handling cask, which stores the canister, from being exposed to radiation materials. Thus, this system quickly and safely performs all working operations in order for superior work efficiency and high safety.

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.

The present invention is directed towards systems and methods for converting spent nuclear fuel (SNF) to fluoride salt fuel for use in a molten salt reactor. By utilizing nitrogen trifluoride, the entire content of a SNF solution may be fluorinated and oxidized, such that it is fit for inclusion in a molten salt reactor system. This process avoids drawbacks of traditional reprocessing since separation is avoided. The present invention utilizes a fuel conversion setup to maintain precise thermal conditions to cause fluorination of the constituents of the SNF while minimizing or avoiding volatilization.

Calorimeter for measuring the linear residual power of at least a portion or piece of a spent or new nuclear fuel rod. The invention essentially consists of a calorimeter whose core is delimited by a block of radioactive and thermal radiation-absorbing material surrounded by a housing of thermal insulation material that thermally isolates the core from the ambient environment. The block and the housing are each in two parts that can be separated for the easy and rapid insertion of a spent fuel rod. The calorimeter is instrumented with temperature sensors distributed along its length, which are inserted into the block and / or the housing to measure the linear residual power of the inserted fuel rod. Figure for the abstract: Fig. 2A

The present invention relates to a spent nuclear fuel disposal container facilitating heat dissipation, the container having a plurality of spherical thermal conductors, disposed between a spent nuclear fuel canister accommodated therein and a storage container accommodating the spent nuclear fuel canister, thereby effectively dissipating heat generated from the spent nuclear fuel canister.

The application provides a DAPhen ligand and a preparation method and application thereof, and a method for separating lanthanide elements and actinide elements from waste liquid, and belongs to the technical field of extraction separation. The application starts from the design of a ligand molecular structure, develops a new DAPhen ligand by designing the structure of the ligand, and ensures high distribution ratio of Eu, and meanwhile, the introduction of the water-soluble ligand also ensures efficient stripping of Am, and the lanthanide-actinide separation factor SF of four DAPhen ligands is up to 320, and the separation effect is good. Eu / Am In addition, the water-soluble ligand and the extraction kinetics are good, and balance can be reached in 10 minutes. The application provides a new idea for in-depth understanding of lanthanide-actinide separation, and provides technical support for establishing an advanced spent nuclear fuel reprocessing system and efficiently utilizing secondary actinide elements.