WO2019114315A1 - 掺杂碳化硼的燃料芯块及其制造方法 - Google Patents

掺杂碳化硼的燃料芯块及其制造方法 Download PDF

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WO2019114315A1
WO2019114315A1 PCT/CN2018/101368 CN2018101368W WO2019114315A1 WO 2019114315 A1 WO2019114315 A1 WO 2019114315A1 CN 2018101368 W CN2018101368 W CN 2018101368W WO 2019114315 A1 WO2019114315 A1 WO 2019114315A1
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boron carbide
fuel pellet
particle diameter
blank
doped
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PCT/CN2018/101368
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English (en)
French (fr)
Inventor
黄华伟
严岩
刘彤
李锐
任啟森
孙茂州
马赵丹丹
薛佳祥
龚星
高思宇
郭达禧
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广东核电合营有限公司
中广核研究院有限公司
中国广核集团有限公司
中国广核电力股份有限公司
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Publication of WO2019114315A1 publication Critical patent/WO2019114315A1/zh

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    • 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
    • G21C3/623—Oxide fuels
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    • 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
    • C04B35/565—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 based on silicon carbide
    • C04B35/575—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 based on silicon carbide obtained by pressure sintering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
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    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/628—Coating the powders or the macroscopic reinforcing agents
    • C04B35/62802—Powder coating materials
    • C04B35/62828—Non-oxide ceramics
    • C04B35/62831—Carbides
    • C04B35/62834—Silicon carbide
    • 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
    • G21C3/626—Coated fuel particles
    • 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
    • G21C3/64—Ceramic dispersion fuel, e.g. cermet
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    • 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
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
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    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
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    • 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
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
    • C04B2235/3225—Yttrium oxide or oxide-forming salts thereof
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    • 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
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    • 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
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    • 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
    • C04B2235/5454—Particle size related information expressed by the size of the particles or aggregates thereof nanometer sized, i.e. below 100 nm
    • C—CHEMISTRY; METALLURGY
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    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
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    • C04B2235/74—Physical characteristics
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    • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
    • C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
    • C04B2237/84—Joining of a first substrate with a second substrate at least partially inside the first substrate, where the bonding area is at the inside of the first substrate, e.g. one tube inside another tube
    • 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

Definitions

  • the present invention relates to the field of nuclear fuel technology, and in particular to a method for manufacturing a boron carbide doped fuel pellet and a boron carbide doped fuel pellet.
  • nuclear power generation is a clean energy source, and the advantages of nuclear energy are obvious.
  • the proportion of nuclear power energy is increasing, and the status of nuclear power generation is increasing.
  • countries are constantly developing nuclear energy and building new nuclear power plants.
  • nuclear energy uses fission of heavy metal elements such as uranium to generate energy, and fission forms fission products with certain radioactivity. Therefore, radiation protection and prevention of leakage of radioactive products are the key to nuclear power safety and a prerequisite for the development of nuclear energy.
  • a number of nuclear radioactive leaks have occurred on the road of peaceful use of nuclear energy by human beings, making the ability to improve the fault tolerance of fuel assemblies of traditional UO 2 -Zr alloy systems has become the focus of attention.
  • UO 2 has a high melting point and a small swelling of radiation, but has a low thermal conductivity, and the fission gas inclusion capacity is poor under deep combustion.
  • the low thermal conductivity UO 2 pellets result in a large temperature gradient during operation of the UO 2 -Zr fuel system, with the center temperature of the fuel rod reaching above 1500 °C.
  • the low thermal conductivity pellet has a high core temperature, a large fission gas release rate, and a temperature gradient causes thermal stress in the pellet to reduce the safety of the fuel element. Under the condition of water loss accident, the higher the core temperature of the pellet, the more energy is transferred to the fuel rod cladding. The higher the pellet temperature, the greater the release of fission gas, which increases the risk of damage of the fuel rod cladding. Even caused the core to melt. Therefore, the development of advanced nuclear fuel, research on high thermal conductivity, low fission gas release rate of nuclear fuel pellets is the key to improve the fault tolerance of nuclear reactor fuel components.
  • Inert matrix dispersion fuel is a high-pressure gas-cooled reactor fuel ball technology.
  • TRISO microspheres are used as nuclear fuel carriers. TRISO microspheres are dispersed in SiC matrix. It is an important fault-tolerant fuel pellet. research direction.
  • the high thermal conductivity SiC substrate coated with TRISO microspheres protects the integrity of the TRISO microspheres and plays an important role in conducting heat.
  • the structural design of the TRISO microspheres ensures that the pellets suppress fuel under deep burnup. The release of the pellet fission gas.
  • the SiC matrix of the IMDP nuclear fuel pellet has a high melting point, high thermal conductivity, and low release rate of the TRISO microsphere fission gas. These characteristics improve the fault tolerance of the fuel element of the IMDP fuel pellet.
  • the IMDP pellet is a dispersion of TRISO microspheres in the SiC matrix. Its structural characteristics make the uranium loading of the IMDP pellets low. Therefore, the 235 U enrichment of the IMDP pellets is higher than that of the UO 2 pellets under the same conditions. However, the higher the concentration of 235 U of the fuel pellet, the stronger the initial reactivity of the nuclear reactor. In order to flatten the initial reactivity, the American Oak Grove National Laboratory added Gd 2 O 3 (yttria) or Er 2 O 3 (yttria) combustible poisons to the fuel pellets, of which Gd 2 O 3 is microspheres. In a manner of addition, Er 2 O 3 is added to the SiC matrix in a powder form. The neutron absorption cross sections of Gd 2 O 3 and Er 2 O 3 are large, and the initial reactivity of the fuel pellets is significantly reduced, but they have the following disadvantages:
  • the flammability of Gd and Er elements is lower than that of B element, and the enthalpy elements formed by the reaction have larger neutron absorption cross sections. These enthalpy elements have stronger neutron absorption capacity and lower fuel during the service of fuel elements. Neutron economy of components;
  • the compound having a low melting point formed by Gd 2 O 3 and Er 2 O 3 and the NITE phase in the SiC matrix is volatilized during the sintering process, and the content of the added combustible poison is not easily controlled.
  • the technical problem to be solved by the present invention is to provide a method for manufacturing a boron carbide doped fuel pellet and a boron carbide doped fuel pellet for improving the fuel economy of the fuel pellet.
  • the technical solution adopted by the present invention to solve the technical problem thereof is to provide a method for manufacturing a boron carbide doped fuel pellet, comprising the following steps:
  • the first formula bismuth oxide 0.5-8%, alumina 0.5-10%, silicon oxide 0-8%, boron carbide 0.5-15%, the balance is silicon carbide;
  • the second formula bismuth oxide 0.5-8%, alumina 0.5-10%, silicon oxide 0-8%, the balance is silicon carbide;
  • the powder to be pressed is placed in the tube body blank, and is molded into a core body body which is fitted in the tube body blank, and densified and sintered to obtain a boron carbide doped fuel pellet.
  • the cerium oxide has a particle diameter of 20 nm to 20 ⁇ m
  • the alumina has a particle diameter of 10 nm to 30 ⁇ m
  • the silicon oxide has a particle diameter of 10 nm to 50 ⁇ m
  • the boron carbide The particle size is from 0.5 ⁇ m to 10 ⁇ m
  • the silicon carbide has a particle diameter of 10 nm to 50 ⁇ m
  • the cerium oxide has a particle diameter of 20 nm to 20 ⁇ m
  • the alumina has a particle diameter of 10 nm to 30 ⁇ m
  • the silicon oxide has a particle diameter of 10 nm to 50 ⁇ m
  • the silicon carbide has a particle diameter of 10 nm to 50 ⁇ m. 10 nm - 50 ⁇ m.
  • the mass of the ethanol is 1-2 times the mass of all the raw materials in the first formulation; the polyethyleneimine is added in an amount of 0.5 of the mass of all the raw materials. -2%;
  • the mass of the ethanol is 1-2 times the mass of all the raw materials in the second formulation; the polyethyleneimine is added in an amount of 0.5 to 2% by mass of all the raw materials.
  • the coating layer has a thickness of 0.5-5 mm.
  • step S4 the pressure of molding is 20-200 MPa;
  • step S5 the pressure of the powder to be pressed to form the core blank is 20-200 MPa; and the pressure of the powder to be pressed is formed to match the pressure of the core blank to 60-200 MPa.
  • the matching gap between the core body blank and the tube body blank is 0.1-0.25 mm.
  • step S5 the densification sintering is carried out under an inert atmosphere at a temperature of from 1700 ° C to 2100 ° C and a pressure of from 10 to 40 MPa.
  • the volume fraction of the TRISO particles in the produced fuel pellet is 30-60%.
  • the present invention also provides a boron carbide doped fuel pellet obtained by the manufacturing method described in any of the above.
  • the invention also provides another fuel cell block doped with boron carbide, comprising an inner core and a tube body coated outside the inner core, wherein the inner core is formed by sintering the inner core body, and the tube body is formed by sintering the tube body blank. ;
  • the inner core comprises the following mass percentages of raw materials: 0.5-8% yttrium oxide, 0.5-10% alumina, 0-8% silicon oxide, 0.5-15% boron carbide, and the balance is silicon carbide; Including TRISO particles dispersed therein;
  • the tube body comprises the following mass percentages of raw materials: 0.5-8% yttrium oxide, 0.5-10% alumina, 0-8% silica, and the balance being silicon carbide.
  • the invention has the beneficial effects that the fuel pellet of the invention is an inert-based dispersing fuel pellet (IMDP), and a B 4 C combustible poison is added to the inner core material of the fuel pellet, and the content can be precisely controlled, and the B 4 C is in the inner core.
  • IMDP inert-based dispersing fuel pellet
  • the medium distribution is uniform, and the prepared fuel pellet effectively flattens the neutron reactivity when the core is initially charged, and does not affect the physical properties such as the melting point, thermal conductivity and strength of the fuel pellet.
  • the fuel pellets of the present invention are useful in fuel assemblies in water reactors and molten salt reactors and have broad industrial prospects.
  • FIG. 1 is a schematic cross-sectional structural view of a boron carbide doped fuel pellet of the present invention
  • Figure 2 is a graph showing the relationship between the different B 4 C content and the neutron multiplication coefficient of the fuel pellet in the present invention.
  • the method for manufacturing a boron carbide doped fuel pellet of the present invention may comprise the following steps:
  • the first formulation yttrium oxide (Y 2 O 3 ) 0.5-8%, alumina (Al 2 O 3 ) 0.5-10%, silicon oxide (SiO 2 ) 0-8%, boron carbide (B 4 C) 0.5- 15%, the balance is silicon carbide (SiC).
  • Each of the raw materials is in the form of a powder, wherein the cerium oxide has a particle diameter of 20 nm to 20 ⁇ m, the alumina has a particle diameter of 10 nm to 30 ⁇ m, the silicon oxide has a particle diameter of 10 nm to 50 ⁇ m, and the boron carbide has a particle diameter of 0.5 ⁇ m to 10 ⁇ m.
  • the silicon carbide has a particle diameter of 10 nm to 50 ⁇ m.
  • the second formulation bismuth oxide 0.5-8%, alumina 0.5-10%, silicon oxide 0-8%, the balance is silicon carbide.
  • Each of the raw materials is in the form of a powder, wherein the cerium oxide has a particle diameter of 20 nm to 20 ⁇ m, the alumina has a particle diameter of 10 nm to 30 ⁇ m, the silicon oxide has a particle diameter of 10 nm to 50 ⁇ m, and the silicon carbide has a particle diameter of 10 nm to 50 ⁇ m.
  • the mass of ethanol is 1-2 times the mass of all the raw materials in the first formulation; the amount of polyethyleneimine added is 0.5-2% of the mass of all the raw materials.
  • the raw materials and ethanol were first placed in a nylon ball mill jar, then polyethyleneimine was added, and ball milled on a planetary ball mill for 0-24 h.
  • the mass of ethanol is 1-2 times the mass of all the raw materials in the second formulation; the amount of polyethyleneimine added is 0.5-2% of the mass of all the raw materials.
  • the raw materials and ethanol were first placed in a nylon ball mill jar, then polyethyleneimine was added, and ball milled on a planetary ball mill for 0-24 h.
  • the method of drying can be performed by blowing hot air.
  • the slurry forms a coating layer adhered to the outer surface of the TRISO particles 100 (carrier particles).
  • the mass of the ethanol is 3-5 times the mass of the first mixture.
  • the particle size of the TRISO particles is 1 mm; the thickness of the coating formed on the outer surface of the TRISO particles is 0.5-5 mm.
  • the molding pressure is 20-200 MPa.
  • the tube body has a wall thickness of 2-4 mm.
  • the powder to be pressed (all TRISO particles containing the coating layer) prepared in step S3 is previously pressed to form a core body blank, and the core material blank is assembled into the tube body blank, and is dense. Sintering is performed to produce a B 4 C doped fuel pellet.
  • the pressure at which the powder to be pressed is pressed to form a core blank is 20-200 MPa.
  • the matching gap between the core body blank and the tube body blank is 0.1-0.25 mm.
  • the powder to be pressed (all the TRISO particles containing the coating layer) is placed in the tube body blank, molded to form a core body billet which is fitted in the tube body blank, and densified and sintered.
  • a B 4 C doped fuel pellet was produced.
  • the pressure of the molding is 60-200 MPa; preferably, the pressure of the molding is greater than the pressure of the molding to form the tube body blank, and is also greater than the pressure for pressing the core forming body.
  • the densification sintering is carried out under an inert atmosphere, and the pellet is densified by SPS sintering or hot press sintering at a temperature of 1700 ° C to 2100 ° C and a pressure of 10 to 40 MPa.
  • the densification sintering is carried out under an inert atmosphere at a temperature of from 1700 ° C to 2100 ° C and a pressure of from 10 to 40 MPa.
  • An inert gas inert gas may be selected from argon gas or the like.
  • the volume percentage of the TRISO particles 100 is 30-60%.
  • the boron carbide-doped fuel pellets obtained by the centerless grinding process are used to obtain the fuel pellets that meet the size requirements.
  • the boron carbide-doped fuel pellet produced by the manufacturing method of the present invention is an inert-based dispersed fuel pellet (IMDP).
  • IMDP inert-based dispersed fuel pellet
  • the boron carbide doped fuel pellet of the present invention comprises an inner core 10 and a tubular body 20 coated outside the inner core 10.
  • the inner core 10 is formed by sintering a core blank
  • the tubular body 20 is formed by a tube.
  • the body blank is formed after sintering.
  • the inner core 10 comprises the following raw materials of mass percentage: 0.5-8% of yttrium oxide, 0.5-10% of alumina, 0-8% of silicon oxide, 0.5-15% of boron carbide, the balance being silicon carbide;
  • the diameter is 20 nm to 20 ⁇ m
  • the particle diameter of alumina is 10 nm to 30 ⁇ m
  • the particle diameter of silicon oxide is 10 nm to 50 ⁇ m
  • the particle diameter of boron carbide is 0.5 ⁇ m to 10 ⁇ m
  • the particle diameter of silicon carbide is 10 nm to 50 ⁇ m. All raw materials are mixed, pressed, etc.
  • the inner core 10 also includes TRISO particles 100 dispersed therein (in the inner core matrix); the TRISO particles 100 are 30-60% by volume of the fuel pellet.
  • the tube body 20 comprises the following mass percentages of raw materials: 0.5-8% yttrium oxide, 0.5-10% alumina, 0-8% silica, and the balance being silicon carbide.
  • the particle size of the cerium oxide is 20 nm to 20 ⁇ m
  • the particle diameter of the alumina is 10 nm to 30 ⁇ m
  • the particle diameter of the silicon oxide is 10 nm to 50 ⁇ m
  • the particle diameter of the silicon carbide is 10 nm to 50 ⁇ m. All raw materials are mixed, pressed, etc. to form a tubular body blank, which is then densified by sintering to form a tubular body 20 (SiC-NITE).
  • B element is introduced by adding boron carbide (B 4 C), and the flammability of the B element is significantly better than that of Er and Gd, and the neutron absorption cross section of the metamorphic element of B is small. Thereby, the neutron economy of the fuel pellet can be improved.
  • B 4 C has a high melting point and a small vapor pressure. It is not volatile during the manufacturing process of the fuel pellet, and the content precision is controllable to improve the performance of the pellet (such as strength).
  • First formulation 1.8 wt.% of Y 2 O 3 powder having a particle diameter of 20 nm, 3 wt.% of Al 2 O 3 powder having a particle diameter of 10 nm, 1.2 wt.% of SiO 2 powder having a particle diameter of 10 nm, and B 4 having a particle diameter of 0.5 ⁇ m.
  • C powder 0.5 wt.%; the balance is SiC powder having a particle diameter of 100 nm.
  • the second formulation 1.8 wt.% of Y 2 O 3 powder having a particle diameter of 20 nm, 3 wt.% of Al 2 O 3 powder having a particle diameter of 10 nm, 1.2 wt.% of SiO 2 powder having a particle diameter of 10 nm; the balance being a particle diameter of 100 nm SiC powder.
  • the raw powders of the two formulations and the ethanol of 2 times the mass were placed in a nylon ball mill jar, polyethyleneimine (1 wt.% of the raw material powder) was added, and ball milled on a planetary ball mill for 24 hours to form a first mixture and a second. Mixing.
  • the second mixture was compression molded, pressed at a pressure of 80 MPa, and pressed into a round tube blank.
  • the wall thickness of the tube blank is 2-4 mm, and the matching gap with the core blank is 0.1-0.25 mm.
  • the core blank was assembled into a circular tube blank, and then subjected to secondary molding to obtain an IMDP green body at a pressing pressure of 100 MPa; and densified and sintered to obtain a fuel pellet.
  • First formulation 3 wt.% of Y 2 O 3 powder having a particle diameter of 20 nm, 5 wt.% of Al 2 O 3 powder having a particle diameter of 10 nm, 4 wt.% of SiO 2 powder having a particle diameter of 10 nm, and B 4 C powder having a particle diameter of 0.5 ⁇ m. 5 wt.%; the balance is SiC powder having a particle diameter of 100 nm.
  • the second formulation 3 wt.% of Y 2 O 3 powder having a particle diameter of 20 nm, 5 wt.% of Al 2 O 3 powder having a particle diameter of 10 nm, 4 wt.% of SiO 2 powder having a particle diameter of 10 nm, and the balance being SiC powder having a particle diameter of 100 nm. .
  • the raw powders of the two formulations and the ethanol of 2 times the mass were placed in a nylon ball mill jar, polyethyleneimine (1 wt.% of the raw material powder) was added, and ball milled on a planetary ball mill for 24 hours to form a first mixture and a second. Mixing.
  • the second mixture was compression molded, pressed at a pressure of 80 MPa, and pressed into a round tube blank.
  • the wall thickness of the tube blank is 2-4 mm, and the matching gap with the core blank is 0.1-0.25 mm.
  • the core blank was assembled into a circular tube blank, and then subjected to secondary molding to obtain an IMDP green body at a pressing pressure of 100 MPa; and densified and sintered to obtain a fuel pellet.
  • First formulation 3.6 wt.% of Y 2 O 3 powder having a particle diameter of 20 nm, 6 wt.% of Al 2 O 3 powder having a particle diameter of 10 nm, 2.4 wt.% of SiO 2 powder having a particle diameter of 10 nm, and B 4 having a particle diameter of 0.5 ⁇ m.
  • the second formulation 3.6 wt.% of Y 2 O 3 powder having a particle diameter of 20 nm, 6 wt.% of Al 2 O 3 powder having a particle diameter of 10 nm, 2.4 wt.% of SiO 2 powder having a particle diameter of 10 nm; the balance being a particle diameter of 1 ⁇ m. SiC powder.
  • the raw powders of the two formulations and the ethanol of 2 times the mass were placed in a nylon ball mill jar, polyethyleneimine (1 wt.% of the raw material powder) was added, and ball milled on a planetary ball mill for 24 hours to form a first mixture and a second. Mixing.
  • the second mixture was compression molded, pressed at a pressure of 80 MPa, and pressed into a round tube blank.
  • the wall thickness of the tube blank is 2-4 mm, and the matching gap with the core blank is 0.1-0.25 mm.
  • the core blank was assembled into a circular tube blank, and then subjected to secondary molding to obtain an IMDP green body at a pressing pressure of 100 MPa; and densified and sintered to obtain a fuel pellet.

Abstract

一种掺杂碳化硼的燃料芯块及其制造方法，制造方法包括：S1、根据质量百分比称取第一配方和第二配方各原料；S2、分别将第一配方和第二配方的原料与乙醇混合后，加入聚乙烯亚胺，球磨混合均匀，分别形成第一混料和第二混料；S3、取5-20％的第一混料均匀混合在乙醇中形成浆料，将浆料喷洒在滚动的TRISO颗粒表面，烘干形成待压粉料；S4、将第二混料模压形成为管体素坯；S5、预先将待压粉料压制形成内核素坯，将内核素坯装配到管体素坯中，致密化烧结，制得掺杂碳化硼的燃料芯块；或者，将待压粉料置于管体素坯中，模压形成配合在管体素坯中的内核素坯，致密化烧结，制得掺杂碳化硼的燃料芯块。该方法可提高燃料芯块中子经济性。

Description

掺杂碳化硼的燃料芯块及其制造方法 技术领域
本发明涉及核燃料技术领域，尤其涉及一种掺杂碳化硼的燃料芯块的制造方法以及掺杂碳化硼的燃料芯块。
 背景技术
核燃料能量密度高，CO 2等有害气体排放少，是解决目前石化资源紧缺和环境污染严重的重要手段，核能发电是清洁能源，核能的优势明显，核电能源比例不断增大，核能发电的地位越显突出，各国在不断的开发核能并建设新型核电站。然而，核能是利用铀等重金属元素裂变产生能量，裂变会形成具有一定放射性的裂变产物。因此，做好辐射防护和防止放射性产物泄露是核电安全的关键，也是开发核能的前提。在人类和平利用核能的道路上曾发生多起核放射性泄露事件，使得提升传统UO 2-Zr合金体系燃料组件的事故容错能力成为人们关注的焦点。
UO 2熔点高、辐照肿胀小，但热导率低，在深燃耗下裂变气体包容能力差。低热导率的UO 2芯块使得UO 2-Zr燃料体系在运行过程中产生较大的温度梯度，燃料棒中心温度达到1500℃以上。低热导率芯块的芯部温度高，裂变气体释放率大，且温度梯度使得芯块中产生热应力，降低了燃料元件的安全性。在失水事故工况条件下，芯块芯部温度越高，传热至燃料棒包壳的能量越多，芯块温度越高裂变气体释放量越大，增加了燃料棒包壳破损的风险，甚至引发堆芯熔化。因此，开发先进核燃料，研究高热导率、低裂变气体释放率的核燃料芯块是提高核反应堆燃料元件事故容错能力的关键。
惰性基弥散燃料芯块（Inert matrix dispersion fuel 简称IMDP）是借鉴高温气冷堆燃料球技术，以TRISO微球为核燃料载体，TRISO微球弥散分布于SiC基体中，是事故容错燃料芯块的重要研究方向。IMDP芯块高热导率的SiC基体包覆TRISO微球，保护了TRISO微球的完整性，起着传导热量的重要作用，而TRISO微球的结构设计保证了芯块在深燃耗下抑制燃料芯块裂变气体的释放。IMDP核燃料芯块的SiC基体熔点高、热导率高，TRISO微球裂变气体释放率低， 这些特点提升了IMDP燃料芯块的燃料元件的事故容错能力。
IMDP芯块是TRISO微球弥散分布于SiC基体中，其结构特点使得IMDP芯块的铀装量低，因此，在同等条件下IMDP芯块的 235U富集度要高于UO 2芯块。然而，燃料芯块的 235U的富集越高，核反应堆的初始反应性越强。为了展平初始反应性，美国橡树林国家实验室在燃料芯块中，添加了Gd 2O 3（氧化钆）或者Er 2O 3（氧化铒）可燃毒物，其中Gd 2O 3是以微球的方式加入，Er 2O 3是以粉末的方式加入SiC基体中。Gd 2O 3和Er 2O 3中子吸收截面大，燃料芯块的初始反应性降低明显，但它们存在以下缺点：
1、Gd、Er元素的可燃性低于B元素，其反应形成的嬗变元素有较大大的中子吸收截面，这些嬗变元素在燃料元件的服役中、后期吸收中子能力较强，降低了燃料元件的中子经济性；
2、添加的Gd 2O 3微球占据TRISO微球的位置，降低芯块中U装量；
3、直接掺入Er 2O 3粉末在SiC基体中不降低TRISO微球的含量，但会与SiC基体中掺杂的NITE助烧剂形成化合物，增加低熔点第二相化合物的体积含量，降低IMDP芯块的高温稳定性；
4、Gd 2O 3和Er 2O 3与SiC基体中的NITE相形成低熔点的化合物在烧结过程中易挥发，添加的可燃毒物含量不易精确控制。
技术问题
本发明要解决的技术问题在于，提供一种提高燃料芯块中子经济性的掺杂碳化硼的燃料芯块的制造方法以及掺杂碳化硼的燃料芯块。
 技术解决方案
本发明解决其技术问题所采用的技术方案是：提供一种掺杂碳化硼的燃料芯块的制造方法，包括以下步骤：
S1、根据质量百分比称取第一配方和第二配方各原料；
第一配方：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%、碳化硼0.5-15%，余量为碳化硅；
第二配方：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%，余量为碳化硅；
S2、分别将第一配方和第二配方的所述原料与乙醇混合后，加入聚乙烯亚胺，球磨混合均匀，分别形成第一混料和第二混料；
S3、取5-20%的第一混料均匀混合在乙醇中形成浆料，将所述浆料喷洒在滚动的TRISO颗粒表面，烘干形成待压粉料；其中，所述浆料形成粘附在所述TRISO颗粒外表面的包覆层；
S4、将第二混料模压形成为管体素坯；
S5、预先将所述待压粉料压制形成内核素坯，将所述内核素坯装配到所述管体素坯中，致密化烧结，制得掺杂碳化硼的燃料芯块；或者，
将所述待压粉料置于所述管体素坯中，模压形成配合在所述管体素坯中的内核素坯，致密化烧结，制得掺杂碳化硼的燃料芯块。
优选地，在第一配方中，所述氧化钇的粒径为20nm-20μm，所述氧化铝的粒径为10nm-30μm，所述氧化硅的粒径为10nm-50μm，所述碳化硼的粒径为0.5μm -10μm，所述碳化硅的粒径为10nm-50μm；
在第二配方中，所述氧化钇的粒径为20nm-20μm，所述氧化铝的粒径为10nm-30μm，所述氧化硅的粒径为10nm-50μm，所述碳化硅的粒径为10nm-50μm。
优选地，步骤S2中，在第一混料中，所述乙醇的质量为所述第一配方中所有原料质量的1-2倍；所述聚乙烯亚胺的加入量为所有原料质量的0.5-2%；
在第二混料中，所述乙醇的质量为所述第二配方中所有原料质量的1-2倍；所述聚乙烯亚胺的加入量为所有原料质量的0.5-2%。
优选地，步骤S3中，所述包覆层的厚度为0.5-5mm。
优选地，步骤S4中，模压的压力为20-200Mpa；
步骤S5中，将所述待压粉料压制形成内核素坯的压力为20-200Mpa；将所述待压粉料模压形成配合在内核素坯的压力为60-200Mpa。
优选地，步骤S5中，在所述内核素坯装配到所述管体素坯中，所述内核素坯与管体素坯之间的配合间隙为0.1-0.25mm。
优选地，步骤S5中，致密化烧结在惰性气氛下进行，烧结的温度为1700℃-2100℃，压力为10-40 Mpa。
优选地，步骤S5中，在制得的所述燃料芯块中，所述TRISO颗粒的体积百分比为30-60%。
本发明还提供一种掺杂碳化硼的燃料芯块，采用以上任一项所述的制造方法制得。
本发明还提供另一种掺杂碳化硼的燃料芯块，包括内芯以及包覆在内芯外的管体，内芯由内核素坯烧结后形成，管体由管体素坯烧结后形成；
所述内芯包括以下质量百分比的原料：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%、碳化硼0.5-15%，余量为碳化硅；所述内芯还包括弥散分布在其中的TRISO颗粒；
所述管体包括以下质量百分比的原料：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%，余量为碳化硅。
 有益效果
本发明的有益效果：本发明的燃料芯块为惰性基弥散燃料芯块（IMDP），在燃料芯块的内芯原料中添加B 4C可燃毒物，含量可精确控制，B 4C在内芯中分布均匀，制得的燃料芯块有效地展平堆芯初始装料时的中子反应性，同时不影响燃料芯块的熔点、热导率、强度等物理性能。
本发明的燃料芯块可用于水堆和熔盐堆中的燃料组件，具有广泛的工业前景。
 附图说明
下面将结合附图及实施例对本发明作进一步说明，附图中：
图1是本发明的掺杂碳化硼的燃料芯块的剖面结构示意图；
图2是本发明中不同B 4C含量与燃料芯块中子增殖系数的关系曲线图。
本发明的实施方式
本发明的掺杂碳化硼的燃料芯块的制造方法，可包括以下步骤：
S1、根据质量百分比称取第一配方和第二配方各原料；
第一配方：氧化钇（Y 2O 3）0.5-8%、氧化铝（Al 2O 3）0.5-10%、氧化硅（SiO 2）0-8%、碳化硼（B 4C）0.5-15%，余量为碳化硅（SiC）。各原料均为粉末状，其中，氧化钇的粒径为20nm-20μm，氧化铝的粒径为10nm-30μm，氧化硅的粒径为10nm-50μm，碳化硼的粒径为0.5μm -10μm，碳化硅的粒径为10nm-50μm。
第二配方：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%，余量为碳化硅。各原料均为粉末状，其中，氧化钇的粒径为20nm-20μm，氧化铝的粒径为10nm-30μm，氧化硅的粒径为10nm-50μm，碳化硅的粒径为10nm-50μm。
S2、将第一配方的原料与乙醇混合后，加入聚乙烯亚胺，球磨混合均匀，形成第一混料；将第二配方的原料与乙醇混合后，加入聚乙烯亚胺，球磨混合均匀，形成第二混料。
在第一混料中，乙醇的质量为第一配方中所有原料质量的1-2倍；聚乙烯亚胺的加入量为所有原料质量的0.5-2%。先将原料和乙醇置入尼龙球磨罐中，再添加聚乙烯亚胺，在行星球磨机上球磨0-24h。
在第二混料中，乙醇的质量为第二配方中所有原料质量的1-2倍；聚乙烯亚胺的加入量为所有原料质量的0.5-2%。先将原料和乙醇置入尼龙球磨罐中，再添加聚乙烯亚胺，在行星球磨机上球磨0-24h。
S3、取5-20%（质量百分比）的第一混料均匀混合在乙醇中形成浆料，将浆料喷洒在滚动的TRISO颗粒表面，烘干形成待压粉料。
烘干的方式可采用吹热风。浆料形成粘附在TRISO颗粒100（载体颗粒）外表面的包覆层。
该步骤中，乙醇的质量为第一混料质量的3-5倍。TRISO颗粒的粒径为1mm；浆料在TRISO颗粒外表面形成的包覆层的厚度为0.5-5mm。
S4、将第二混料模压形成为管体素坯。
模压的压力为20-200Mpa。管体素坯的壁厚为2-4mm。
S5、在一种实施方式中，预先将步骤S3制得的待压粉料（所有的含有包覆层的TRISO颗粒）压制形成内核素坯，将内核素坯装配到管体素坯中，致密化烧结，制得掺杂B 4C的燃料芯块。将待压粉料压制形成内核素坯的压力为20-200Mpa。在内核素坯装配到管体素坯中，内核素坯与管体素坯之间的配合间隙为0.1-0.25mm。
在另一种实施方式中，将待压粉料（所有的含有包覆层的TRISO颗粒）置于管体素坯中，模压形成配合在管体素坯中的内核素坯，致密化烧结，制得掺杂B 4C的燃料芯块。模压的压力为60-200Mpa；优选地，该模压的压力大于模压形成管体素坯的压力，也大于压制形成内核素坯的压力。
上述两种实施方式中，致密化烧结在惰性气氛下进行，采用SPS烧结或热压烧结使芯块致密，烧结的温度为1700℃-2100℃，压力为10-40 Mpa。
致密化烧结在惰性气氛下进行，烧结的温度为1700℃-2100℃，压力为10-40 Mpa。惰性气氛的惰性气体可选用氩气等。
在制得的掺杂碳化硼的燃料芯块中，TRISO颗粒100的体积百分比为30-60%。
根据芯块尺寸要求，采用无心磨床处理制得的掺杂碳化硼的燃料芯块，获得满足尺寸要求的燃料芯块。
本发明的制造方法制得的掺杂碳化硼的燃料芯块，为惰性基弥散燃料芯块（IMDP）。
如图1所示，本发明的掺杂碳化硼的燃料芯块包括内芯10以及包覆在内芯10外的管体20，内芯10由内核素坯烧结后形成，管体20由管体素坯烧结后形成。
其中，内芯10包括以下质量百分比的原料：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%、碳化硼0.5-15%，余量为碳化硅；氧化钇的粒径为20nm-20μm，氧化铝的粒径为10nm-30μm，氧化硅的粒径为10nm-50μm，碳化硼的粒径为0.5μm -10μm，碳化硅的粒径为10nm-50μm。所有原料经混合、压制等操作形成内核素坯，再通过烧结致密主要形成内芯基体（SiC-NITE-B 4C）。内芯10还包括弥散分布在其中（内芯基体中）的TRISO颗粒100；TRISO颗粒100占燃料芯块体积百分比30-60%。
管体20包括以下质量百分比的原料：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%，余量为碳化硅。氧化钇的粒径为20nm-20μm，氧化铝的粒径为10nm-30μm，氧化硅的粒径为10nm-50μm，碳化硅的粒径为10nm-50μm。所有原料经混合、压制等操作形成管体素坯，再通过烧结致密化形成管体20（SiC-NITE）。
本发明的掺杂碳化硼的燃料芯块中，通过添加碳化硼（B 4C），引入B元素，B元素的可燃性明显优于Er、Gd，B的嬗变元素的中子吸收截面小，从而可提高燃料芯块的中子经济性。B 4C具有熔点高、蒸汽压小的特定，在燃料芯块的制造烧结过程中不易挥发，含量精度可控，改善芯块性能（如强度等）。
 
以下通过具体实施例对本发明进一步说明。
实施例1
称取以下配方原料：
第一配方：粒径20nm的Y 2O 3粉末1.8wt.%，粒径10nm的Al 2O 3粉末3wt.%，粒径10nm的SiO 2粉末1.2wt.%，粒径0.5μm的B 4C粉末0.5wt.%；余量为粒径100nm 的SiC粉末。
第二配方：粒径20nm的Y 2O 3粉末1.8wt.%，粒径10nm的Al 2O 3粉末3wt.%，粒径10nm的SiO 2粉末1.2wt.%；余量为粒径100nm 的SiC粉末。
分别将两个配方的原料粉末与2倍质量的乙醇置入尼龙球磨罐中，加入聚乙烯亚胺（原材料粉末的1wt.%），在行星球磨机上球磨24h，形成第一混料和第二混料。
称取5-20 wt.%的第一混料均匀混于的乙醇中，形成浆料，将浆料喷洒在滚动的TRISO颗粒表面，吹热风，乙醇挥发后TRISO颗粒外表面黏附一层具有一定结合力的混合粉末包覆层。将获得的含包覆层的TRISO颗粒微球压制成内核素坯。
将第二混料模压成形，压制压力80MPa，压制成圆管素坯。圆管素坯的壁厚2-4mm，与内核素坯的配合间隙0.1-0.25mm。
将内核素坯装配至圆管素坯中，然后二次模压成型，获得IMDP素坯，压制压力100Mpa；致密化烧结，获得燃料芯块。
实施例2
第一配方：粒径20nm的Y 2O 3粉末3wt.%，粒径10nm的Al 2O 3粉末5wt.%，粒径10nm的SiO 2粉末4wt.%，粒径0.5μm的B 4C粉末5wt.%；余量为粒径100nm 的SiC粉末。
第二配方：粒径20nm的Y 2O 3粉末3wt.%，粒径10nm的Al 2O 3粉末5wt.%，粒径10nm的SiO 2粉末4wt.%；余量为粒径100nm 的SiC粉末。
分别将两个配方的原料粉末与2倍质量的乙醇置入尼龙球磨罐中，加入聚乙烯亚胺（原材料粉末的1wt.%），在行星球磨机上球磨24h，形成第一混料和第二混料。
称取5-20 wt.%的第一混料均匀混于的乙醇中，形成浆料，将浆料喷洒在滚动的TRISO颗粒表面，吹热风，乙醇挥发后TRISO颗粒外表面黏附一层具有一定结合力的混合粉末包覆层。将获得的含包覆层的TRISO颗粒微球压制成内核素坯。
将第二混料模压成形，压制压力80MPa，压制成圆管素坯。圆管素坯的壁厚2-4mm，与内核素坯的配合间隙0.1-0.25mm。
将内核素坯装配至圆管素坯中，然后二次模压成型，获得IMDP素坯，压制压力100Mpa；致密化烧结，获得燃料芯块。
实施例3
第一配方：粒径20nm的Y 2O 3粉末3.6wt.%，粒径10nm的Al 2O 3粉末6wt.%，粒径10nm的SiO 2粉末2.4wt.%，粒径0.5μm的B 4C粉末15wt.%；余量为粒径1μm的SiC粉末。
第二配方：粒径20nm的Y 2O 3粉末3.6wt.%，粒径10nm的Al 2O 3粉末6wt.%，粒径10nm的SiO 2粉末2.4wt.%；余量为粒径1μm 的SiC粉末。
分别将两个配方的原料粉末与2倍质量的乙醇置入尼龙球磨罐中，加入聚乙烯亚胺（原材料粉末的1wt.%），在行星球磨机上球磨24h，形成第一混料和第二混料。
称取5-20 wt.%的第一混料均匀混于的乙醇中，形成浆料，将浆料喷洒在滚动的TRISO颗粒表面，吹热风，乙醇挥发后TRISO颗粒外表面黏附一层具有一定结合力的混合粉末包覆层。将获得的含包覆层的TRISO颗粒微球压制成内核素坯。
将第二混料模压成形，压制压力80MPa，压制成圆管素坯。圆管素坯的壁厚2-4mm，与内核素坯的配合间隙0.1-0.25mm。
将内核素坯装配至圆管素坯中，然后二次模压成型，获得IMDP素坯，压制压力100Mpa；致密化烧结，获得燃料芯块。
可以理解地，本发明的具体实施例并不限于上述实施例1-3。根据不同B 4C含量制得的燃料芯块，测试不同B 4C含量（0%、0.5%、1%、5%、10%及15%）对燃料芯块中子无限增殖系数的影响，如图2所示，从图2所示曲线可知，B 4C的加入有效地展平堆芯初始装料时的中子反应性，展平效果好。
以上所述仅为本发明的实施例，并非因此限制本发明的专利范围，凡是利用本发明说明书及附图内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本发明的专利保护范围内。

Claims (10)

  1. 一种掺杂碳化硼的燃料芯块的制造方法，其特征在于，包括以下步骤：
    S1、根据质量百分比称取第一配方和第二配方各原料；
    第一配方：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%、碳化硼0.5-15%，余量为碳化硅；
    第二配方：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%，余量为碳化硅；
    S2、分别将第一配方和第二配方的所述原料与乙醇混合后，加入聚乙烯亚胺，球磨混合均匀，分别形成第一混料和第二混料；
    S3、取5-20%的第一混料均匀混合在乙醇中形成浆料，将所述浆料喷洒在滚动的TRISO颗粒表面，烘干形成待压粉料；其中，所述浆料形成粘附在所述TRISO颗粒外表面的包覆层；
    S4、将第二混料模压形成为管体素坯；
    S5、预先将所述待压粉料压制形成内核素坯，将所述内核素坯装配到所述管体素坯中，致密化烧结，制得掺杂碳化硼的燃料芯块；或者，
    将所述待压粉料置于所述管体素坯中，模压形成配合在所述管体素坯中的内核素坯，致密化烧结，制得掺杂碳化硼的燃料芯块。
  2. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，在第一配方中，所述氧化钇的粒径为20nm-20μm，所述氧化铝的粒径为10nm-30μm，所述氧化硅的粒径为10nm-50μm，所述碳化硼的粒径为0.5μm -10μm，所述碳化硅的粒径为10nm-50μm；
    在第二配方中，所述氧化钇的粒径为20nm-20μm，所述氧化铝的粒径为10nm-30μm，所述氧化硅的粒径为10nm-50μm，所述碳化硅的粒径为10nm-50μm。
  3. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，步骤S2中，在第一混料中，所述乙醇的质量为所述第一配方中所有原料质量的1-2倍；所述聚乙烯亚胺的加入量为所有原料质量的0.5-2%；
    在第二混料中，所述乙醇的质量为所述第二配方中所有原料质量的1-2倍；所述聚乙烯亚胺的加入量为所有原料质量的0.5-2%。
  4. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，步骤S3中，所述包覆层的厚度为0.5-5mm。
  5. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，步骤S4中，模压的压力为20-200Mpa；
    步骤S5中，将所述待压粉料压制形成内核素坯的压力为20-200Mpa；将所述待压粉料模压形成配合在内核素坯的压力为60-200Mpa。
  6. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，步骤S5中，在所述内核素坯装配到所述管体素坯中，所述内核素坯与管体素坯之间的配合间隙为0.1-0.25mm。
  7. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，步骤S5中，致密化烧结在惰性气氛下进行，烧结的温度为1700℃-2100℃，压力为10-40 Mpa。
  8. 根据权利要求1所述的掺杂碳化硼的燃料芯块的制造方法，其特征在于，步骤S5中，在制得的所述燃料芯块中，所述TRISO颗粒的体积百分比为30-60%。
  9. 一种掺杂碳化硼的燃料芯块，其特征在于，采用权利要求1-8任一项所述的制造方法制得。
  10. 一种掺杂碳化硼的燃料芯块，其特征在于，包括内芯以及包覆在内芯外的管体，内芯由内核素坯烧结后形成，管体由管体素坯烧结后形成；
    所述内芯包括以下质量百分比的原料：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%、碳化硼0.5-15%，余量为碳化硅；所述内芯还包括弥散分布在其中的TRISO颗粒；
    所述管体包括以下质量百分比的原料：氧化钇0.5-8%、氧化铝0.5-10%、氧化硅0-8%，余量为碳化硅。
PCT/CN2018/101368 2017-12-14 2018-08-20 掺杂碳化硼的燃料芯块及其制造方法 WO2019114315A1 (zh)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1004388B (zh) * 1984-12-05 1989-05-31 西屋电气公司 核燃料芯块或关于核燃料芯块的改进
CN101281797A (zh) * 2007-04-04 2008-10-08 西屋电气有限责任公司 硼或浓缩10硼在uo2中的用途
CN104700905A (zh) * 2015-02-17 2015-06-10 上海核工程研究设计院 一种载硼整体型和离散型组合可燃毒物燃料组件
US20150170767A1 (en) * 2013-11-07 2015-06-18 Francesco Venneri FULLY CERAMIC MICRO-ENCAPSULATED (FCM) FUEL FOR CANDUs AND OTHER REACTORS
CN105225702A (zh) * 2015-09-23 2016-01-06 中科华核电技术研究院有限公司 高安全性燃料棒及其制造方法
CN106971764A (zh) * 2017-04-13 2017-07-21 中国工程物理研究院材料研究所 一种惰性基弥散燃料芯块的快速制备工艺
US20170287575A1 (en) * 2016-03-29 2017-10-05 Ultra Safe Nuclear Corporation Fully ceramic microencapsulated fuel fabricated with burnable poison as sintering aid
CN108182979A (zh) * 2017-12-14 2018-06-19 广东核电合营有限公司 掺杂碳化硼的燃料芯块及其制造方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2810785B1 (fr) * 2000-06-21 2002-08-23 Commissariat Energie Atomique Element combustible et reacteur nucleaire a refrigerant gazeux utilisant des elements combustibles de ce type
US9099204B2 (en) * 2009-07-23 2015-08-04 Colorado School Of Mines Nuclear battery based on hydride/thorium fuel
US20150357056A1 (en) * 2014-04-09 2015-12-10 Colorado School Of Mines Reactor unit control system for space and terrestrial applications
CN107093468B (zh) * 2017-05-27 2020-05-05 中国工程物理研究院材料研究所 一种ZrC惰性基弥散芯块核燃料及其制法和用途

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1004388B (zh) * 1984-12-05 1989-05-31 西屋电气公司 核燃料芯块或关于核燃料芯块的改进
CN101281797A (zh) * 2007-04-04 2008-10-08 西屋电气有限责任公司 硼或浓缩10硼在uo2中的用途
US20150170767A1 (en) * 2013-11-07 2015-06-18 Francesco Venneri FULLY CERAMIC MICRO-ENCAPSULATED (FCM) FUEL FOR CANDUs AND OTHER REACTORS
CN104700905A (zh) * 2015-02-17 2015-06-10 上海核工程研究设计院 一种载硼整体型和离散型组合可燃毒物燃料组件
CN105225702A (zh) * 2015-09-23 2016-01-06 中科华核电技术研究院有限公司 高安全性燃料棒及其制造方法
US20170287575A1 (en) * 2016-03-29 2017-10-05 Ultra Safe Nuclear Corporation Fully ceramic microencapsulated fuel fabricated with burnable poison as sintering aid
CN106971764A (zh) * 2017-04-13 2017-07-21 中国工程物理研究院材料研究所 一种惰性基弥散燃料芯块的快速制备工艺
CN108182979A (zh) * 2017-12-14 2018-06-19 广东核电合营有限公司 掺杂碳化硼的燃料芯块及其制造方法

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