CN107500767B - Uranium carbide pellet and preparation method thereof, fuel rod - Google Patents

Uranium carbide pellet and preparation method thereof, fuel rod Download PDF

Info

Publication number
CN107500767B
CN107500767B CN201710719413.9A CN201710719413A CN107500767B CN 107500767 B CN107500767 B CN 107500767B CN 201710719413 A CN201710719413 A CN 201710719413A CN 107500767 B CN107500767 B CN 107500767B
Authority
CN
China
Prior art keywords
pellet
uranium
uranium carbide
green body
preparation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201710719413.9A
Other languages
Chinese (zh)
Other versions
CN107500767A (en
Inventor
薛佳祥
张显生
刘彤
李锐
严岩
李思功
黄华伟
龚星
任啟森
严俊
卢志威
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China General Nuclear Power Corp
China Nuclear Power Technology Research Institute Co Ltd
CGN Power Co Ltd
Original Assignee
China General Nuclear Power Corp
China Nuclear Power Technology Research Institute Co Ltd
CGN Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China General Nuclear Power Corp, China Nuclear Power Technology Research Institute Co Ltd, CGN Power Co Ltd filed Critical China General Nuclear Power Corp
Priority to CN201710719413.9A priority Critical patent/CN107500767B/en
Publication of CN107500767A publication Critical patent/CN107500767A/en
Priority to RO202000363A priority patent/RO134863A2/en
Priority to GB2007032.2A priority patent/GB2581903B/en
Priority to PCT/CN2018/101376 priority patent/WO2019037688A1/en
Application granted granted Critical
Publication of CN107500767B publication Critical patent/CN107500767B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/5158—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on actinide compounds
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/42—Selection of substances for use as reactor fuel
    • G21C3/58—Solid reactor fuel Pellets made of fissile material
    • G21C3/62—Ceramic fuel
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/38—Non-oxide ceramic constituents or additives
    • C04B2235/3852—Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
    • C04B2235/422—Carbon
    • C04B2235/424—Carbon black
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
    • C04B2235/422—Carbon
    • C04B2235/425—Graphite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5436—Particle size related information expressed by the size of the particles or aggregates thereof micrometer sized, i.e. from 1 to 100 micron
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5445—Particle size related information expressed by the size of the particles or aggregates thereof submicron sized, i.e. from 0,1 to 1 micron
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
    • C04B2235/608—Green bodies or pre-forms with well-defined density
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6562—Heating rate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6567—Treatment time
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/658—Atmosphere during thermal treatment
    • C04B2235/6581—Total pressure below 1 atmosphere, e.g. vacuum
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/66—Specific sintering techniques, e.g. centrifugal sintering
    • C04B2235/661—Multi-step sintering
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/77—Density
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Abstract

The invention discloses a kind of uranium carbide pellets and preparation method thereof, fuel rod.The preparation method of uranium carbide pellet, comprising the following steps: S1, weigh uranium nitride powder and carbon source according to molar ratio 1:0.8-1.5 and be added in solvent, form slurry after mixing；S2, the slurry is dried, obtains mixed powder；S3, the green body that the mixed powder is pressed into 50% or more density；S4, high temperature pressure-free sintering, obtain the uranium carbide pellet of consistency >=95%.In the present invention, by uranium nitride and carbon source as raw material, two processes of carbothermic reduction reaction and densification sintering are realized under high temperature pressure-free sintering, the hot-pressing sintering technique low using production efficiency is not needed, it does not need to introduce sintering aid, avoids the problem that reducing pellet fusing point, batch sinter may be implemented, it consumes energy low, the industrialized production suitable for fuel pellet.

Description

Uranium carbide pellet and preparation method thereof, fuel rod
Technical field
The present invention relates to nuclear reactor technology fields more particularly to a kind of uranium carbide pellet and preparation method thereof, fuel rod.
Background technique
Existing commercialization presurized water reactor nuclear fuel is mainly uranium dioxide (UO2) pellet, but UO2Pellet thermal conductivity is low, center line temperature Degree is high, even if safe shutdown when accident occurs, still stores a large amount of decay heats, the feelings of coolant loss in pellet Condition be left thermal conductivity go out difficulty, so that fuel rod clad temperature is quickly raised to danger level.Existing Zirconium alloy material is changed due to itself Property is learned, apparent zirconium-water reaction takes place at 650 DEG C or more, this reaction is exothermic reaction, and discharges a large amount of hydrogen, sternly Deteriorate fuel assembly safety again, can lead to reactor core thawing and the acutely quick-fried equal catastrophic effects of hydrogen.
If using uranium carbide (UC) pellet, thermal conductivity is higher, and uranium density is also promoted, from economical and safety From the point of view of angle, there is apparent advantage.
The preparation of existing uranium carbide pellet is broadly divided into two steps, first is that uranium carbide powder synthesizes, generallys use dioxy Change uranium at high temperature carbon thermal reduction method synthesize uranium carbide powder；Second is that pellet densification sintering, generallys use addition sintering The pressureless sintering of auxiliary agent or the hot pressed sintering assisted using outfield.
There is the following in the preparation of existing uranium carbide pellet:
1, oxygen atom is easily dissolved in uranium carbide powder, dissolving in for oxygen atom can make UC2It stabilizes, makes U2C3It decomposes.Carbonization It is dissolved the concentration of oxygen in uranium up to 12.5at%, the reduction of uranium carbide thermal conductivity will be caused.Uranium carbide is more than 200 DEG C or oxygen in temperature When partial pressure is more than 20kPa, it is easy to be oxidized to UO2Or the oxide of other uranium.Therefore, the powder and mixing processed of uranium carbide are both needed to It carries out in the environment of argon filling, also has higher requirements to the purity of argon.
2, when addition sintering aid carries out the sintering of uranium carbide pellet, although advantageous to densifying, the fusing point of pellet can be made Apparent reduction, safety decline occurs.
3, the hot pressed sintering assisted using outfield, the densification of uranium carbide pellet easy to accomplish.But the every furnace one of such methods Secondary to be sintered a pellet, efficiency is extremely low, energy consumption is big, equipment requirement is high, is not suitable for industrialized mass production.
Summary of the invention
The technical problem to be solved in the present invention is that provide a kind of reaction synthesis completed with one step of sintering densification, can work The preparation method and uranium carbide pellet obtained, the fuel with the uranium carbide pellet of the uranium carbide pellet of industryization batch production Stick.
The technical solution adopted by the present invention to solve the technical problems is: a kind of preparation method of uranium carbide pellet is provided, The following steps are included:
S1, uranium nitride powder and carbon source are weighed according to molar ratio 1:0.8-1.5 and is added in solvent, formed after mixing Slurry；
S2, the slurry is dried, obtains mixed powder；
S3, the green body that the mixed powder is pressed into 50% or more density；
S4, high temperature pressure-free sintering, obtain the uranium carbide pellet of consistency >=95%.
In the preparation process in accordance with the present invention, in step S1, the uranium nitride powder purity is greater than 95%, partial size 0.1-50 μm；
The carbon source is carbon black and/or graphite, and purity is greater than 95%, and partial size is 0.1-50 μm.
In the preparation process in accordance with the present invention, in step S1, the solvent is ethyl alcohol or acetone.
In the preparation process in accordance with the present invention, step S3 the following steps are included:
S3.1, by the mixed powder under the pressure of 5-30Mpa pre-molding；
S3.2, the green body vacuum sealing by pre-molding carry out high pressure with green body of the pressure of 150-300Mpa to sealing Compacting obtains the green body of 50% or more density after pressure maintaining.
In the preparation process in accordance with the present invention, in step S3.1, the mixed powder is put into pellet steel mold and is carried out in advance It is molded；
In step S3.2, by the green body of pre-molding oilpaper vacuum sealing, using cold isostatic press to the green body of sealing Carry out high pressure compacting.
In the preparation process in accordance with the present invention, step S4 the following steps are included:
S4.1, the step S3 green body obtained is put into high temperature pressure-free furnace, under vacuum conditions, with the speed of 5-30 DEG C/min Rate is warming up to 1300 DEG C -1600 DEG C and keeps the temperature 0.5-4h；
S4.2, under an inert atmosphere, is warming up to 1700 DEG C -2000 DEG C with the rate of 5-30 DEG C/min and keeps the temperature 1-14h, obtain Obtain uranium carbide pellet.
In the preparation process in accordance with the present invention, in step S4.2, argon gas is passed through toward the high temperature pressure-free furnace and keeps one big Air pressure forms inert atmosphere.
In the preparation process in accordance with the present invention, in the uranium carbide pellet of acquisition, uranium, carbon, nitrogen-atoms ratio are 1:(0.8- 1.5): (0-0.2).
The present invention also provides a kind of uranium carbide pellets, are made using preparation method described in any of the above item.
The present invention also provides a kind of fuel rods, including above-mentioned uranium carbide pellet.
Beneficial effects of the present invention: by uranium nitride and carbon source as raw material, carbon heat is realized also under high temperature pressure-free sintering Original reaction and two processes of densification sintering do not need the hot-pressing sintering technique low using production efficiency, do not need to introduce and burn Auxiliary agent is tied, avoids the problem that reducing pellet fusing point, batch sinter may be implemented, low, the industrialization suitable for fuel pellet of consuming energy Production.
Specific embodiment
The preparation method of uranium carbide pellet of the invention, comprising the following steps:
S1, uranium nitride powder and carbon source are weighed according to molar ratio 1:0.8-1.5 and is added in solvent, formed after mixing Slurry.
Wherein, uranium nitride (UN) powder purity is greater than 95%, and partial size is 0.1-50 μm.Carbon source (C) is carbon black and/or stone Ink, purity are greater than 95%, and partial size is 0.1-50 μm.
Solvent can be ethyl alcohol or acetone.Uranium nitride powder and carbon source are added in solvent, it is therefore an objective to be sufficiently mixed the two And it is evenly distributed.
S2, slurry is dried, obtains mixed powder.
Gained slurry can be dried by rotary evaporation, obtain dry mixed powder.Drying time is evaporated according to practical feelings Condition regulation.
S3, the green body that mixed powder is pressed into 50% or more density.
Step S3 further can comprise the following steps that
S3.1, by mixed powder under the pressure of 5-30Mpa pre-molding.
S3.2, the green body vacuum sealing by pre-molding carry out high pressure with green body of the pressure of 150-300Mpa to sealing Compacting obtains the green body of 50% or more density after pressure maintaining.
Dwell time can according to circumstances depending on, such as 5min, main purpose are to stablize pressed blank shape.
Specifically, in step S3.1, mixed powder is put into pellet steel mold, 10Mpa pressure can be applied and carry out precompressed Molding.In step S3.2, the green body of pre-molding oilpaper vacuum sealing is carried out using green body of the cold isostatic press to sealing As the high pressure of 200Mpa is suppressed.
S4, high temperature pressure-free sintering, obtain the uranium carbide pellet of consistency >=95%.
Step S4 further can comprise the following steps that
S4.1, the step S3 green body obtained is put into high temperature pressure-free furnace, under vacuum conditions, with the speed of 5-30 DEG C/min Rate is warming up to 1300 DEG C -1600 DEG C and keeps the temperature 0.5-4h；The all stage keeps vacuum.
The step mainly realizes the carbothermic reduction reaction of green body, is reacted fully and progress and is completed by heat preservation, to be formed Uranium carbide.
S4.2, under an inert atmosphere, is warming up to 1700 DEG C -2000 DEG C with the rate of 5-30 DEG C/min and keeps the temperature 1-14h, obtain Obtain uranium carbide pellet.
After heat preservation, it is cooled to room temperature, that is, can be taken off uranium carbide pellet.
The step mainly realizes the densification of green body, forms the pellet with scheduled consistency.
Alternatively, in step S4.2, it can be passed through argon gas toward high temperature pressure-free furnace and keep an atmospheric pressure, form inertia Atmosphere.
In preparation method of the invention, by the reaction in-situ pressureless sintering of uranium nitride and carbon source, pass through solid solution and carbon nitrogen Vacancy defect migrates mass transfer and realizes densification.
In the uranium carbide pellet that the present invention obtains, uranium, carbon, nitrogen-atoms ratio are 1:(0.8-1.5): (0-0.2), above-mentioned ratio Example is adjustable.The regulative mode of uranium carbon atomic ratio and solid solution nitrogen include feed change partial size and component proportion, change reaction temperature and React soaking time, change sintering temperature and sintered heat insulating time and change sintering atmosphere etc..
Uranium carbide pellet of the invention is made using above-mentioned preparation method.
Fuel rod of the invention, including above-mentioned uranium carbide pellet.
Below by way of specific embodiment, the invention will be further described.
Embodiment 1
The uranium carbide pellet for preparing consistency 98% is 1:1.2 weighing according to the molar ratio of UN:C: 249 grams of UN powder, carbon black 14.4 grams.
Using ethyl alcohol as solvent, with 120 revs/min of speed, Si is used3N4Ball roll-type mixing 24 hours, gained slurry passes through rotation Uniformly mixed mixed powder is obtained after turning evaporation drying.Mixed powder is put into pellet steel mold, the pressure of 10MPa is first applied Power carries out precompressed and it is vacuum-packed to oilpaper to reuse cold isostatic press then by preforming green body oilpaper vacuum sealing The isobaric load that green body applies 200MPa made pellet green body initial density reach 50% or more at 200MPa pressure maintaining 5 minutes.
Green body is taken out, is put into high temperature pressure-free furnace and carries out reaction-sintered.Using pressureless sintering, in the first step stage of reaction, Heating rate is 10 DEG C/min, is warming up to 1400 DEG C and keeps the temperature 1 hour, which must keep vacuum environment.After heat preservation, Stopping vacuumizes, and high-purity argon gas is passed through in furnace and remains an atmospheric pressure, then is warming up to the heating rate of 10 DEG C/min 1800 DEG C and heat preservation 4 hours.After heat preservation, it is cooled to room temperature, takes out pellet.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum does not obviously deviate.Through detecting Know: being 98% by 1800 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 4 hours, the porosity 2%, aperture is 100nm, and be open pore.
Embodiment 2
Prepare the uranium carbide pellet of consistency 95%.Carbon source is changed into graphite by the carbon black in embodiment 1.According to UN:C's Molar ratio is 1:0.8 weighing: 249 grams of UN powder, 9.6 grams of graphite.
Green body is prepared in the same manner as shown in Example 1, and in-situ reaction temperature is 1500 DEG C and keeps the temperature 2 hours, sintering temperature Degree keeps the temperature 1 hour for 1900 DEG C.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum slightly deviates to the left, illustrates exist Nitrogen solid solution.It is learnt through detection: being 95% by 1900 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 1 hour, stomata Rate is 5%, aperture 500nm, and is open pore.
Embodiment 3
Prepare the uranium carbide pellet of consistency 99%.It is 1:1 weighing according to the molar ratio of UN:C: 249 grams of UN powder, graphite 12 Gram.
Green body, reaction in-situ are prepared in the same manner as shown in Example 1, prepare core within pressureless sintering 3 hours at 2000 DEG C Block.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum does not obviously deviate.Through detecting Know: being 99% by 2000 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 14 hours, exist without open pore.
Embodiment 4
Prepare the uranium carbide pellet of consistency 95%.Carbon source is changed into graphite by the carbon black in embodiment 1.According to UN:C's Molar ratio is 1:1.5 weighing: 249 grams of UN powder, 18 grams of graphite.
Green body is prepared in the same manner as shown in Example 1, and in-situ reaction temperature is 1600 DEG C and keeps the temperature 1.5 hours, sintering Temperature is 1700 DEG C and keeps the temperature 10 hours.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum slightly deviates to the right, illustrates exist Rich carbon.It is learnt through detection: being 95% by 1700 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 10 hours, the porosity It is 5%, aperture 200nm, and be open pore.
Embodiment 5
Prepare the uranium carbide pellet of consistency 97%.Use carbon black for raw material.Claim according to the molar ratio of UN:C for 1:0.9 Amount: 249 grams of UN powder, 10.8 grams of carbon black.
Using acetone as solvent, with 120 revs/min of speed, with SiC ball roll-type mixing 12 hours, gained slurry passed through rotation Uniformly mixed mixed powder is obtained after turning evaporation drying.Mixed powder is put into pellet steel mold, the pressure of 20MPa is first applied Power carries out precompressed and it is vacuum-packed to oilpaper to reuse cold isostatic press then by preforming green body oilpaper vacuum sealing The isobaric load that green body applies 250MPa made pellet green body initial density reach 50% or more at 250MPa pressure maintaining 5 minutes.
Green body is taken out, is put into high temperature pressure-free furnace and carries out reaction-sintered.Using pressureless sintering, in the first step stage of reaction, Heating rate is 20 DEG C/min, is warming up to 1550 DEG C and keeps the temperature 0.5 hour, which must keep vacuum environment.Heat preservation terminates Afterwards, stop vacuumizing, high-purity argon gas is passed through in furnace and remains an atmospheric pressure, then be warming up to the heating rate of 20 DEG C/min 1900 DEG C and heat preservation 8 hours.After heat preservation, it is cooled to room temperature, takes out pellet.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum does not obviously deviate.Through detecting Know: being 97% by 1900 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 8 hours, the porosity 3%, aperture is 300nm, and be open pore.
Embodiment 6
Prepare the uranium carbide pellet of consistency 100%.Use carbon black for raw material.Claim according to the molar ratio of UN:C for 1:1.1 Amount: 249 grams of UN powder, 13.2 grams of carbon black.
Green body is prepared according to method same as Example 5, in-situ reaction temperature is 1600 DEG C and keeps the temperature 2 hours, sintering temperature Degree keeps the temperature 12 hours for 1950 DEG C.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum does not obviously deviate.Through detecting Know: being 100% by 1950 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 12 hours, the porosity 0%.
Embodiment 7
Prepare the uranium carbide pellet of consistency 95.5%.Use carbon black for raw material.Claim according to the molar ratio of UN:C for 1:1.5 Amount: 249 grams of UN powder, 18 grams of carbon black.
Using acetone as solvent, with 120 revs/min of speed, with SiC ball roll-type mixing 24 hours, gained slurry passed through rotation Uniformly mixed mixed powder is obtained after turning evaporation drying.Mixed powder is put into pellet steel mold, the pressure of 15MPa is first applied Power carries out precompressed and it is vacuum-packed to oilpaper to reuse cold isostatic press then by preforming green body oilpaper vacuum sealing The isobaric load that green body applies 150MPa made pellet green body initial density reach 50% or more at 150MPa pressure maintaining 5 minutes.
Green body is taken out, is put into high temperature pressure-free furnace and carries out reaction-sintered.Using pressureless sintering, in the first step stage of reaction, Heating rate is 30 DEG C/min, is warming up to 1600 DEG C and keeps the temperature 2 hours, which must keep vacuum environment.After heat preservation, Stopping vacuumizes, and high-purity argon gas is passed through in furnace and remains an atmospheric pressure, then is warming up to the heating rate of 30 DEG C/min 1850 DEG C and heat preservation 6 hours.After heat preservation, it is cooled to room temperature, takes out pellet.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum slightly deviates to the right, illustrates exist Rich carbon.It is learnt through detection: being 95.5% by 1850 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 6 hours, stomata Rate is 4.5%.
Embodiment 8
Prepare the uranium carbide pellet of consistency 96.5%.Use carbon black for raw material.Claim according to the molar ratio of UN:C for 1:1.3 Amount: 249 grams of UN powder, 15.6 grams of carbon black.
Using acetone as solvent, with 120 revs/min of speed, Si is used3N4Ball roll-type mixing 18 hours, gained slurry passes through rotation Uniformly mixed mixed powder is obtained after turning evaporation drying.Mixed powder is put into pellet steel mold, the pressure of 30MPa is first applied Power carries out precompressed and it is vacuum-packed to oilpaper to reuse cold isostatic press then by preforming green body oilpaper vacuum sealing The isobaric load that green body applies 300MPa made pellet green body initial density reach 50% or more at 300MPa pressure maintaining 5 minutes.
Green body is taken out, is put into high temperature pressure-free furnace and carries out reaction-sintered.Using pressureless sintering, in the first step stage of reaction, Heating rate is 15 DEG C/min, is warming up to 1450 DEG C and keeps the temperature 2.5 hours, which must keep vacuum environment.Heat preservation terminates Afterwards, stop vacuumizing, high-purity argon gas is passed through in furnace and remains an atmospheric pressure, then be warming up to the heating rate of 15 DEG C/min 1950 DEG C and heat preservation 2 hours.After heat preservation, it is cooled to room temperature, takes out pellet.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum slightly deviates to the right, illustrates exist Rich carbon.It is learnt through detection: being 96.5% by 1950 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 2 hours, stomata Rate is 3.5%.
Embodiment 9
Prepare the uranium carbide pellet of consistency 96%.Use carbon black for raw material.Claim according to the molar ratio of UN:C for 1:0.8 Amount: 249 grams of UN powder, 9.6 grams of carbon black.
Using acetone as solvent, with 120 revs/min of speed, Si is used3N4Ball roll-type mixing 20 hours, gained slurry passes through rotation Uniformly mixed mixed powder is obtained after turning evaporation drying.Mixed powder is put into pellet steel mold, the pressure of 5MPa is first applied Power carries out precompressed and it is vacuum-packed to oilpaper to reuse cold isostatic press then by preforming green body oilpaper vacuum sealing The isobaric load that green body applies 150MPa made pellet green body initial density reach 50% or more at 150MPa pressure maintaining 5 minutes.
Green body is taken out, is put into high temperature pressure-free furnace and carries out reaction-sintered.Using pressureless sintering, in the first step stage of reaction, Heating rate is 5 DEG C/min, is warming up to 1300 DEG C and keeps the temperature 4 hours, which must keep vacuum environment.After heat preservation, Stopping vacuumizes, and high-purity argon gas is passed through in furnace and remains an atmospheric pressure, then is warming up to 1850 with the heating rate of 5 DEG C/min DEG C and keep the temperature 5 hours.After heat preservation, it is cooled to room temperature, takes out pellet.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum slightly deviates to the left, illustrates exist It is dissolved nitrogen.It is learnt through detection: being 96% by 1850 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 5 hours, stomata Rate is 4%.
Embodiment 10
Prepare the uranium carbide pellet of consistency 98.5%.Use carbon black for raw material.Claim according to the molar ratio of UN:C for 1:1.1 Amount: 249 grams of UN powder, 13.2 grams of carbon black.
Using acetone as solvent, with 240 revs/min of speed, Si is used3N4Ball roll-type mixing 24 hours, gained slurry passes through rotation Uniformly mixed mixed powder is obtained after turning evaporation drying.Mixed powder is put into pellet steel mold, the pressure of 10MPa is first applied Power carries out precompressed and it is vacuum-packed to oilpaper to reuse cold isostatic press then by preforming green body oilpaper vacuum sealing The isobaric load that green body applies 200MPa made pellet green body initial density reach 50% or more at 200MPa pressure maintaining 5 minutes.
Green body is taken out, is put into high temperature pressure-free furnace and carries out reaction-sintered.Using pressureless sintering, in the first step stage of reaction, Heating rate is 10 DEG C/min, is warming up to 1350 DEG C and keeps the temperature 4 hours, which must keep vacuum environment.After heat preservation, Stopping vacuumizes, and high-purity argon gas is passed through in furnace and remains an atmospheric pressure, then is warming up to the heating rate of 10 DEG C/min 1750 DEG C and heat preservation 13 hours.After heat preservation, it is cooled to room temperature, takes out pellet.
Through X-ray diffraction analysis, sintered pellet object is mutually uranium carbide, and diffraction maximum does not obviously deviate.Through detecting Know: being 98.5% by 1750 DEG C of uranium carbide pellet consistency obtained by heat preservation sintering 13 hours, the porosity 1.5%.
The above description is only an embodiment of the present invention, is not intended to limit the scope of the invention, all to utilize this hair Equivalent structure or equivalent flow shift made by bright description is applied directly or indirectly in other relevant technology necks Domain is included within the scope of the present invention.

Claims (9)

1. a kind of preparation method of uranium carbide pellet, which comprises the following steps:
S1, uranium nitride powder and carbon source are weighed according to molar ratio 1:0.8-1.5 and is added in solvent, form slurry after mixing Material；
S2, the slurry is dried, obtains mixed powder；
S3, the green body that the mixed powder is pressed into 50% or more density；
S4, high temperature pressure-free sintering, obtain the uranium carbide pellet of consistency >=95%；
Step S4 the following steps are included:
S4.1, the step S3 green body obtained is put into high temperature pressure-free furnace, under vacuum conditions, with the rate liter of 5-30 DEG C/min Temperature is to 1300 DEG C -1600 DEG C and keeps the temperature 0.5-4h；
S4.2, under an inert atmosphere, is warming up to 1700 DEG C -2000 DEG C with the rate of 5-30 DEG C/min and keeps the temperature 1-14h, obtains carbon Change uranium pellet.
2. the preparation method of uranium carbide pellet according to claim 1, which is characterized in that in step S1, the uranium nitride Powder purity is greater than 95%, and partial size is 0.1-50 μm；
The carbon source is carbon black and/or graphite, and purity is greater than 95%, and partial size is 0.1-50 μm.
3. the preparation method of uranium carbide pellet according to claim 1, which is characterized in that in step S1, the solvent is Ethyl alcohol or acetone.
4. the preparation method of uranium carbide pellet according to claim 1, which is characterized in that step S3 the following steps are included:
S3.1, by the mixed powder under the pressure of 5-30Mpa pre-molding；
S3.2, the green body vacuum sealing by pre-molding carry out high pressure compacting with green body of the pressure of 150-300Mpa to sealing, The green body of 50% or more density is obtained after pressure maintaining.
5. the preparation method of uranium carbide pellet according to claim 4, which is characterized in that, will be described mixed in step S3.1 Conjunction powder, which is put into pellet steel mold, carries out pre-molding；
In step S3.2, the green body of pre-molding oilpaper vacuum sealing is carried out using green body of the cold isostatic press to sealing High pressure compacting.
6. the preparation method of uranium carbide pellet according to claim 1, which is characterized in that in step S4.2, toward the height Warm non-press stove is passed through argon gas and keeps an atmospheric pressure, forms inert atmosphere.
7. the preparation method of uranium carbide pellet according to claim 1-6, which is characterized in that the uranium carbide of acquisition In pellet, uranium, carbon, nitrogen-atoms ratio are 1:(0.8-1.5): (0-0.2).
8. a kind of uranium carbide pellet, which is characterized in that be made using the described in any item preparation methods of claim 1-7.
9. a kind of fuel rod, which is characterized in that including uranium carbide pellet according to any one of claims 8.
CN201710719413.9A 2017-08-21 2017-08-21 Uranium carbide pellet and preparation method thereof, fuel rod Active CN107500767B (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
CN201710719413.9A CN107500767B (en) 2017-08-21 2017-08-21 Uranium carbide pellet and preparation method thereof, fuel rod
RO202000363A RO134863A2 (en) 2017-08-21 2018-08-20 Uranium carbide pellet, preparation method therefor and fuel rod
GB2007032.2A GB2581903B (en) 2017-08-21 2018-08-20 Uranium carbide pellet, preparation method therefor, and fuel rod
PCT/CN2018/101376 WO2019037688A1 (en) 2017-08-21 2018-08-20 Uranium carbide pellet, preparation method therefor, and fuel rod

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710719413.9A CN107500767B (en) 2017-08-21 2017-08-21 Uranium carbide pellet and preparation method thereof, fuel rod

Publications (2)

Publication Number Publication Date
CN107500767A CN107500767A (en) 2017-12-22
CN107500767B true CN107500767B (en) 2019-09-10

Family

ID=60692024

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710719413.9A Active CN107500767B (en) 2017-08-21 2017-08-21 Uranium carbide pellet and preparation method thereof, fuel rod

Country Status (4)

Country Link
CN (1) CN107500767B (en)
GB (1) GB2581903B (en)
RO (1) RO134863A2 (en)
WO (1) WO2019037688A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107500767B (en) * 2017-08-21 2019-09-10 中广核研究院有限公司 Uranium carbide pellet and preparation method thereof, fuel rod
CN109461509B (en) * 2018-09-29 2020-11-10 中广核研究院有限公司 Inert matrix dispersion fuel pellet and preparation method thereof
CN113012834A (en) * 2019-12-20 2021-06-22 中核北方核燃料元件有限公司 Preparation method of uranium nitride composite uranium trisilicon two-fuel pellet
CN112735618B (en) * 2020-12-30 2022-06-28 中核北方核燃料元件有限公司 Preparation method of SiC-based UCO core fuel pellet
CN116655382A (en) * 2023-05-22 2023-08-29 中国科学院过程工程研究所 Method for preparing uranium carbide pellets by spark plasma sintering

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105469838A (en) * 2015-12-23 2016-04-06 中广核研究院有限公司 Fuel assembly and fuel rod capable of improving reactor security of fuel assembly
CN107010960A (en) * 2017-04-13 2017-08-04 中国工程物理研究院材料研究所 A kind of preparation method and applications of uranium base double carbide

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9620248B2 (en) * 2011-08-04 2017-04-11 Ultra Safe Nuclear, Inc. Dispersion ceramic micro-encapsulated (DCM) nuclear fuel and related methods
CN107500767B (en) * 2017-08-21 2019-09-10 中广核研究院有限公司 Uranium carbide pellet and preparation method thereof, fuel rod

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105469838A (en) * 2015-12-23 2016-04-06 中广核研究院有限公司 Fuel assembly and fuel rod capable of improving reactor security of fuel assembly
CN107010960A (en) * 2017-04-13 2017-08-04 中国工程物理研究院材料研究所 A kind of preparation method and applications of uranium base double carbide

Also Published As

Publication number Publication date
GB2581903B (en) 2022-03-23
CN107500767A (en) 2017-12-22
WO2019037688A1 (en) 2019-02-28
RO134863A2 (en) 2021-03-30
GB2581903A (en) 2020-09-02
GB202007032D0 (en) 2020-06-24

Similar Documents

Publication Publication Date Title
CN107500767B (en) Uranium carbide pellet and preparation method thereof, fuel rod
CN102173813B (en) Preparation method of complex phase ceramic material containing zirconium boride
CN109553419B (en) Pneumatic solid-phase sintered boron carbide complex-phase ceramic and preparation method thereof
CN110204341B (en) (Hf, Ta, Nb, Ti) B2High-entropy ceramic powder and preparation method thereof
WO1988005032A1 (en) Silicon carbide sintering
CN106830942B (en) Porous B4C ceramic skeleton and its freezing injection moulding process
CN112142477B (en) Nano lignin-silicon nitride based ceramic and preparation method thereof
CN100396650C (en) Method for preparing Ti2AlC ceramic material
CN113788703B (en) Method for preparing silicified graphite through carbon source modification and reaction infiltration and silicified graphite
CN105272229A (en) Ceramic containing pyrochlore phase zirconic acid gadolinium powder and preparation method of ceramic
CN102757223A (en) Rare-earth boride/boron carbide composite neutron absorption material and preparation method thereof
CN110484796A (en) A kind of high entropy ceramic particle of transition metal carbide and preparation method thereof
CN106517225B (en) Superfine M1-xTixB2Method for preparing powder
CN108249925A (en) A kind of preparation method of complete ceramic microencapsulated fuel pellet
CN112794719A (en) Normal pressure sintered anti-irradiation silicon carbide ceramic material and preparation method thereof
CN113416076A (en) Preparation method of self-reinforced silicon carbide ceramic material
CN115650728A (en) Preparation method of graphite for single crystal thermal field
CN109336607A (en) A kind of boron carbide preparation method
CN109665848B (en) Ultrahigh-temperature SiC-HfB2Composite ceramic and preparation method and application thereof
CN101734920B (en) Titanium nitride porous ceramics and preparation method thereof
CN102924083B (en) Method for preparing zirconium carbide ceramic powder
CN103073300A (en) Method for realizing low-temperature sintering of transition metal nitride ceramics
CN113582700A (en) Preparation method of low-cost titanium boride ceramic composite material
CN104388817A (en) High-strength-toughness sintered iron nickel alloy and preparation method thereof
CN104591769A (en) Al/Mg/B toughened and strengthened ceramic and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant