CN115547518A - Boron-containing spherical fuel element for high-temperature gas cooled reactor - Google Patents
Boron-containing spherical fuel element for high-temperature gas cooled reactor Download PDFInfo
- Publication number
- CN115547518A CN115547518A CN202211181727.5A CN202211181727A CN115547518A CN 115547518 A CN115547518 A CN 115547518A CN 202211181727 A CN202211181727 A CN 202211181727A CN 115547518 A CN115547518 A CN 115547518A
- Authority
- CN
- China
- Prior art keywords
- fuel
- boron
- layer
- temperature gas
- cooled reactor
- 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.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C5/00—Moderator or core structure; Selection of materials for use as moderator
- G21C5/12—Moderator or core structure; Selection of materials for use as moderator characterised by composition, e.g. the moderator containing additional substances which ensure improved heat resistance of the moderator
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C5/00—Moderator or core structure; Selection of materials for use as moderator
- G21C5/12—Moderator or core structure; Selection of materials for use as moderator characterised by composition, e.g. the moderator containing additional substances which ensure improved heat resistance of the moderator
- G21C5/126—Carbonic moderators
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C5/00—Moderator or core structure; Selection of materials for use as moderator
- G21C5/14—Moderator or core structure; Selection of materials for use as moderator characterised by shape
- G21C5/16—Shape of its constituent parts
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Ceramic Products (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses a boron-containing spherical fuel element for a high-temperature gas cooled reactor, which sequentially comprises a fuel area and a fuel-free area from inside to outside; the fuel region comprises coated fuel particles and a graphite matrix; the coated fuel particles are concentric UO from inside to outside in sequence 2 A core, a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB 2 A layer and an outer dense pyrolytic carbon layer; wherein ZrB 2 The thickness of the layer is 5 to 20 μm; the coated fuel particles are dispersed in the graphite matrix. In the boron-containing spherical fuel element for high-temperature gas cooled reactor, zrB is coated on the surface of the SiC layer in the coated fuel particles 2 Coating, avoiding the risk of failure of SiC coatings, and improving the performance of spherical fuel elements 235 The U enrichment degree can reduce the loading quantity of fuel elements, improve the fuel burn-up depth and promote the heat exchange of a high-temperature gas cooled reactor under the same reactor power levelThe economic value.
Description
Technical Field
The invention belongs to the technical field of design of fuel elements of a pebble bed type high-temperature gas cooled reactor, and particularly relates to a boron-containing spherical fuel element for the high-temperature gas cooled reactor.
Background
The pebble bed high-temperature gas cooled reactor is a nuclear reactor using helium as a coolant and graphite as a neutron moderator, is one of the fourth generation advanced reactor types, and is characterized by inherent safety. The pebble-bed high temperature gas cooled reactor includes a core formed of spherical fuel elements stacked within a reactor pressure vessel. The spherical fuel element is composed of a fuel area and a fuel-free area. The fuel region is a sphere coated with fuel particles dispersed in a graphite matrix. The fuel-free zone is a spherical shell of graphite matrix material of the same thickness and thickness as the fuel zone surrounding the fuel zone. The fuel region and the fuel-free region are free of a physical interface. The coated fuel particles are of the all-ceramic, triple isotropic coating (TRISO) type, with a fuel core in the center. Four cladding layers are arranged on the surface of the fuel core. The first layer from inside to outside is low density pyrolytic carbon, the second layer is high density isotropic pyrolytic carbon, the third layer is silicon carbide, and the fourth layer is high density isotropic pyrolytic carbon.
At present, the fuel core in the fuel element of the pebble-bed high-temperature gas cooled reactor has low enrichment degree () 235 U generally not exceeding 10%) uranium dioxide (UO) 2 ) In order to realize flattening of reactor core power distribution and uniform unloading fuel consumption, a fuel circulation mode that spherical fuel elements pass through the reactor core for multiple times is adopted; if the spherical fuel elements pass through the core less frequently, the power peak is higher and is positioned at the top of the core active area, which is unfavorable for the pebble-bed high temperature gas cooled reactor, and therefore, further optimization of the fuel elements in the existing high temperature gas cooled reactor is needed.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the embodiment of the invention provides a boron-containing spherical fuel element for a high-temperature gas cooled reactor.
The embodiment of the invention provides a boron-containing spherical fuel element for a high-temperature gas-cooled reactor, which comprises a fuel area and a fuel-free area from inside to outside in sequence;
the fuel region comprises coated fuel particles and a graphite matrix;
the coated fuel particles are concentric UO from inside to outside in sequence 2 A core, a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB 2 A layer and an outer dense pyrolytic carbon layer; wherein ZrB 2 The thickness of the layer is 5 to 20 μm;
the coated fuel particles are dispersed in the graphite matrix.
In the boron-containing spherical fuel element for high-temperature gas cooled reactor of the embodiment of the invention, zrB with a certain thickness is coated on the SiC layer in the coated fuel particles 2 Coating, zrB 2 The material has a large thermal neutron absorption cross section ( 10 B thermal neutron microscopic absorption cross section 3840 target en, 1 target en =10 -24 cm 2 ) The reactivity of new fuel can be compensated when the pebble bed type high-temperature gas-cooled reactor is initially loaded, and the fuel is preferentially consumed along with the fuel consumption process, so that the fuel backup reactivity of the pebble bed type high-temperature gas-cooled reactor in the transition cycle and the equilibrium cycle is ensured, and the continuous operation of the pebble bed type high-temperature gas-cooled reactor is met.
In some embodiments of the invention, the ZrB 2 The thickness of the layer is preferably 10 to 15 μm.
In some embodiments of the invention, the ZrB 2 The boron element in the layer can adopt natural boron (B) 10 B abundance of 20%), boron enrichment may also be used.
In some embodiments of the present invention, in each of the boron-containing spherical fuel elements for a high temperature gas-cooled reactor, the number of the coated fuel particles is 10000 to 15000.
In some embodiments of the invention, the UO 2 The core is a round ball with the diameter of 0.5 mm.
In some embodiments of the invention, the coated fuel particles have a diameter of any of 0.8mm, 0.92mm, or 1.0 mm.
The invention also provides a preparation method of the boron-containing spherical fuel element for the high-temperature gas cooled reactor, which comprises the following steps:
(1) Preparation of UO by sol-gel process 2 A core: firstly, nitric acid is adopted to dissolve U 3 O 8 Adding organic binder into raw material powder to obtain colloid, and dispersing the colloid into ammonia water to obtain gel particles; then aging, washing, drying and roasting are carried out to obtain UO 3 Particles; finally, the compact UO is obtained by reduction and sintering 2 Ceramic particles;
(2) Preparing coated fuel particles: depositing a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB outside the fuel core in sequence by adopting a chemical vapor deposition method 2 A layer and an outer dense pyrolytic carbon layer;
(3) Preparing boron-containing spherical fuel elements: firstly, coating a layer of graphite powder on the surface of a coated fuel particle, and pressing to obtain a fuel area core sphere; then, a layer of graphite powder is pressed on the surface of the core ball of the fuel area to be used as a fuel-free area; and then carbonizing, turning and purifying at high temperature to obtain the boron-containing spherical fuel element.
In the preparation method of the boron-containing spherical fuel element for the high-temperature gas cooled reactor, the burnable poison ZrB is added into the fuel element 2 Coating of, wherein ZrB 2 Contained in the coating 10 The isotope B is a natural isotope with a larger thermal neutron absorption section, so that the fuel element has larger excess reactivity, the excess reactivity is gradually released along with the consumption of burnable poison, the effects of delaying the power peak value and flattening the power distribution are achieved, and only a small amount of ZrB needs to be added 2 The reactivity control requirements can be met.
In some embodiments of the present invention, in step (1), the organic binder is an ester compound or a mixed solution prepared by dissolving a metal alkoxide in an organic solvent such as methanol, ethanol, propanol, or butanol.
In some embodiments of the invention, in the step (1), the roasting temperature is 500-600 ℃ and the roasting time is 1.5-2 h; the sintering temperature is 1550-1650 ℃, and the sintering time is 16-32 h.
In some embodiments of the invention, in the step (2), the chemical vapor deposition is performed to loosen the pyrolytic carbon layer for 10-30 min at the temperature of 1100-1300 ℃; carrying out chemical vapor deposition on the inner compact pyrolytic carbon layer for 15-45 min at the temperature of 1250-1500 ℃; carrying out chemical vapor deposition on the SiC layer for 2-5 h at 1450-1650 ℃; carrying out chemical vapor deposition ZrB at 1450-1650 DEG C 2 Layer 1-2 h; carrying out chemical vapor deposition on the outer compact pyrolytic carbon layer for 15-45 min at the temperature of 1250-1500 ℃.
In some embodiments of the invention, in the step (3), the carbonization temperature is 750-850 ℃ and the carbonization time is 30-50 h; the temperature of the high-temperature purification is 1150-1250 ℃, and the time is 10-20 h.
The invention has the following advantages and beneficial effects:
(1) In the boron-containing spherical fuel element for high-temperature gas cooled reactor, zrB is coated on the surface of the SiC layer in the coated fuel particles 2 Coating, avoiding the risk of failure of SiC coatings, and improving the performance of spherical fuel elements 235 The U enrichment degree can reduce the loading quantity of fuel elements, improve the fuel burning depth and improve the economic value of a high-temperature gas cooled reactor under the same reactor power level.
(2) By adopting the boron-containing spherical fuel element for the high-temperature gas-cooled reactor, the cycle times of the spherical fuel element in the ball-bed high-temperature gas-cooled reactor can be reduced, the operation times of a fuel loading and unloading system can be reduced, and the reliability can be improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.
Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.
The embodiment of the invention provides a boron-containing spherical fuel element for a high-temperature gas-cooled reactor, which comprises a fuel area and a fuel-free area from inside to outside in sequence;
wherein the fuel region comprises coated fuel particles and a graphite matrix;
the coated fuel particles are concentric UO from inside to outside in sequence 2 A core, a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB 2 A layer and an outer dense pyrolytic carbon layer; wherein ZrB 2 The thickness of the layer is 5 to 20 μm;
the coated fuel particles are dispersed in the graphite matrix.
In the boron-containing spherical fuel element for the high-temperature gas cooled reactor, zrB with a certain thickness is coated on the SiC layer in the coated fuel particles 2 Coating, zrB 2 The material has a large thermal neutron absorption cross section ( 10 B thermal neutron microscopic absorption cross section 3840 target en, 1 target en =10 -24 cm 2 ) The reactivity of new fuel can be compensated when the pebble bed high-temperature gas-cooled reactor is initially loaded, and the fuel is preferentially consumed along with the fuel consumption process, so that the fuel backup reactivity of the pebble bed high-temperature gas-cooled reactor during transition cycle and equilibrium cycle is ensured, and the continuous operation of the pebble bed high-temperature gas-cooled reactor is met; the boron-containing spherical fuel element for the high-temperature gas cooled reactor can be improved 235 The U enrichment degree achieves the purpose of improving the fuel consumption and improves the economy of the ball bed type high-temperature gas cooled reactor; and the use of zirconium boride (ZrB) is also common in commercial pressurized water reactors 2 ) As a neutron burnable poison, the method has rich application experience.
Through reasonable design, the invention preferably coats the burnable poison ZrB on the surface of the SiC layer 2 Coating, not directly applying UO 2 And ZrB 2 Mixed as cladding fuelFuel core of pellet, mainly due to ZrB 2 Helium gas is produced by neutron irradiation (as shown in formula (1): 10 b absorbs neutrons to produce (n, alpha) reaction, lithium and helium), if UO is used 2 And ZrB 2 The fuel core is mixed to be used as a fuel core for coating fuel particles, and then a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and an outer compact pyrolytic carbon layer are deposited outside the fuel core in sequence, so that the internal pressure of the coated fuel particles is increased due to the generated helium gas due to the compactness of the SiC coating, and the failure risk is brought to the SiC coating. In the embodiment of the invention, zrB is added on the surface of the SiC cladding layer 2 Helium generated after neutron irradiation can be released into the outer dense pyrolytic carbon coating layer, and can also be further released into the graphite matrix in the spherical fuel element and released out of the spherical fuel element. Because the high-temperature gas cooled reactor adopts helium as a coolant, a small amount of helium released by the spherical fuel element does not influence the whole primary circuit coolant system of the high-temperature gas cooled reactor.
B+n→Li+He↑ (1)
In some embodiments of the invention ZrB 2 The thickness of the layer is preferably 10 to 15 μm, and may be, for example, 10 μm, 11 μm, 12 μm, 12.5 μm, 14 μm, 15 μm or the like.
In some embodiments of the invention ZrB 2 The boron element in the layer can adopt natural boron (B) 10 B abundance of 20%), boron enrichment may also be used.
In some embodiments of the present invention, the number of the coated fuel particles in each of the boron-containing spherical fuel elements for a high temperature gas cooled reactor is 10000 to 15000.
In some embodiments of the invention, the UO 2 The core is a round ball with the diameter of 0.5 mm.
In some embodiments of the invention, the coated fuel particles have a diameter of any of 0.8mm, 0.92mm, or 1.0 mm.
The invention also provides a preparation method of the boron-containing spherical fuel element for the high-temperature gas cooled reactor, which comprises the following steps:
(1) Preparation of UO by sol-gel process 2 A core: firstly, nitric acid is adopted to dissolve U 3 O 8 Adding organic binder into the raw material powder to obtain colloid, and dispersing the colloid into ammonia water to obtain gel particles; then aging, washing, drying and roasting are carried out to obtain UO 3 Particles; finally, the compact UO is obtained through reduction and sintering 2 Ceramic particles;
(2) Preparing coated fuel particles: depositing a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB outside the fuel core in sequence by adopting a chemical vapor deposition method 2 A layer and an outer dense pyrolytic carbon layer;
(3) Preparing boron-containing spherical fuel elements: firstly, coating a layer of graphite powder on the surface of a coated fuel particle, and pressing to obtain a fuel area core sphere; then, a layer of graphite powder is pressed on the surface of the core ball of the fuel area to be used as a fuel-free area; and then carbonizing, turning and purifying at high temperature to obtain the boron-containing spherical fuel element.
In the preparation method of the boron-containing spherical fuel element for the high-temperature gas cooled reactor, the burnable poison ZrB is added into the fuel element 2 Coating of, wherein ZrB 2 Contained in the coating 10 The isotope B is a natural isotope with a larger thermal neutron absorption section, so that the fuel element has larger excess reactivity, the excess reactivity is gradually released along with the consumption of burnable poison, the effects of delaying the power peak value and flattening the power distribution are achieved, and only a small amount of ZrB needs to be added 2 The reactivity control requirements can be met.
In some embodiments of the present invention, in step (1), the organic binder is an ester compound or a mixed solution prepared by dissolving a metal alkoxide in an organic solvent such as methanol, ethanol, propanol or butanol.
In some embodiments of the present invention, in the step (1), the temperature of the calcination is 500 to 600 ℃, for example, 500 ℃, 520 ℃, 550 ℃, 580 ℃, 600 ℃, etc.; the time is 1.5 to 2 hours, for example, 1.5 hours, 1.6 hours, 1.8 hours, 2 hours and the like;
the sintering temperature is 1550 to 1650 ℃, for example 1550 ℃, 1580 ℃, 1600 ℃, 1620 ℃, 1650 ℃ and the like; the time is 16 to 32 hours, and for example, 16 hours, 18 hours, 20 hours, 24 hours, 28 hours, 30 hours, 32 hours and the like can be used.
In some embodiments of the invention, in the step (2), the chemical vapor deposition is performed to loosen the pyrolytic carbon layer for 10-30 min at the temperature of 1100-1300 ℃; carrying out chemical vapor deposition on the inner compact pyrolytic carbon layer for 15-45 min at the temperature of 1250-1500 ℃; carrying out chemical vapor deposition on the SiC layer for 2-5 h at 1450-1650 ℃; performing chemical vapor deposition of ZrB at 1450-1650 DEG C 2 Layer 1-2 h; carrying out chemical vapor deposition on the outer compact pyrolytic carbon layer for 15-45 min at the temperature of 1250-1500 ℃.
In some embodiments of the present invention, in step (3), the temperature of carbonization is 750 to 850 ℃, for example, 750 ℃, 780 ℃, 800 ℃, 820 ℃, 835 ℃, 850 ℃ and the like; the time is 30 to 50 hours, and may be, for example, 30 hours, 35 hours, 40 hours, 42 hours, 45 hours, 48 hours, 50 hours, or the like.
In some embodiments of the present invention, in step (3), the temperature of high-temperature purification is 1150-1250 ℃, for example, 1150 ℃, 1180 ℃, 1200 ℃, 1220 ℃, 1250 ℃, etc.; the time is 10 to 20 hours, and may be, for example, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, or the like.
The technical scheme of the invention is further described in detail by combining specific examples, wherein the experimental methods without specific conditions noted in the examples are conventional methods and conventional conditions well known in the field.
Example 1
The present embodiment provides a boron-containing spherical fuel element for a high temperature gas cooled reactor, which comprises a fuel region and a non-fuel region in sequence from inside to outside;
the fuel region comprises coated fuel particles and a graphite matrix;
the coated fuel particles are concentric UO from inside to outside in sequence 2 A core, a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB 2 A layer and an outer dense pyrolytic carbon layer;
wherein ZrB 2 The boron element in the layer adopts natural boron, zrB 2 The coating thickness of the layer was 20 μm;
the coated fuel particles are dispersed in the graphite matrix.
The preparation method of the boron-containing spherical fuel element comprises the following steps:
(1) Preparation of UO by sol-gel process 2 A core: firstly 10g U 3 O 8 Mixing the raw material powder with nitric acid with the molar concentration of 16mol/L, and dissolving U by using the nitric acid 3 O 8 Raw material powder; then 5g of polyvinyl alcohol is added and mixed to obtain colloid; dispersing the obtained colloid into 10ml of 25% ammonia water to obtain gel particles; then aging, washing, drying and roasting at 600 ℃ for 1.5h to obtain UO 3 Particles; finally, reducing and sintering for 24h at 1600 ℃ to obtain compact UO 2 Ceramic particles of the UO 2 The diameter of the core is 0.50mm;
(2) Preparing coated fuel particles: depositing a loose pyrolytic carbon layer for 15min at 1250 ℃ outside the fuel core by adopting a chemical vapor deposition method; depositing the inner compact pyrolytic carbon layer at 1350 deg.c for 30min; then depositing a SiC layer for 3 hours at 1600 ℃; depositing ZrB at 1600 DEG C 2 Layer 1.5h; finally, depositing an outer compact pyrolytic carbon layer for 30min at 1350 ℃ to obtain coated fuel particles with the diameter of 0.92 mm;
(3) Preparing boron-containing spherical fuel elements: firstly, coating a layer of graphite powder on the surface of a coated fuel particle, and pressing to obtain a fuel area core sphere; then, a layer of graphite powder is pressed on the surface of the core ball of the fuel area to be used as a fuel-free area; carbonizing at 800 ℃ for 40h, turning, and purifying at 1200 ℃ for 15h to obtain the boron-containing spherical fuel element for the high-temperature gas-cooled reactor, wherein the boron-containing spherical fuel element comprises 12000 coating fuel particles.
Example 2
The present embodiment provides a boron-containing spherical fuel element for a high temperature gas cooled reactor, which comprises a fuel region and a non-fuel region in sequence from inside to outside;
the fuel region comprises coated fuel particles and a graphite matrix;
the coated fuel particles are concentric UO from inside to outside in sequence 2 Core, loose pyrolytic carbon layer and inner compact pyrolytic carbon layerSiC layer, zrB 2 A layer and an outer dense pyrolytic carbon layer;
wherein ZrB 2 Boron in the layer is 10 Enriched boron ZrB with B abundance of 40% 2 The thickness of the coating of the layer was 10 μm;
the coated fuel particles are dispersed in the graphite matrix.
The preparation method of the boron-containing spherical fuel element comprises the following steps:
(1) Preparation of UO by sol-gel process 2 A core: firstly 10g U 3 O 8 Mixing the raw material powder with nitric acid with the molar concentration of 16mol/L, and dissolving U by using the nitric acid 3 O 8 Raw material powder; then 5g of polyvinyl alcohol is added and mixed to obtain colloid; dispersing the obtained colloid into 10ml of 25% ammonia water to obtain gel particles; then aging, washing, drying and roasting at 600 ℃ for 1.5h to obtain UO 3 Particles; finally, reducing and sintering for 24h at 1600 ℃ to obtain compact UO 2 Ceramic particles of the UO 2 The diameter of the core is 0.50mm;
(2) Preparing coated fuel particles: depositing a loose pyrolytic carbon layer outside the fuel core for 10min at 1250 ℃ by adopting a chemical vapor deposition method; depositing the inner compact pyrolytic carbon layer at 1350 deg.c for 15min; then depositing a SiC layer for 2h at 1600 ℃; depositing ZrB at 1600 DEG C 2 Layer 1h; finally, depositing an outer compact pyrolytic carbon layer for 15min at 1350 ℃ to obtain coated fuel particles with the diameter of 0.80 mm;
(3) Preparing boron-containing spherical fuel elements: firstly, coating a layer of graphite powder on the surface of a coated fuel particle, and pressing to obtain a fuel area core sphere; then, a layer of graphite powder is pressed on the surface of the core ball of the fuel area to be used as a fuel-free area; carbonizing at 800 ℃ for 40h, turning, and purifying at 1200 ℃ for 15h to obtain the boron-containing spherical fuel element for the high-temperature gas-cooled reactor, wherein the boron-containing spherical fuel element contains 15000 coated fuel particles.
Example 3
The present embodiment provides a boron-containing spherical fuel element for a high temperature gas cooled reactor, which comprises a fuel region and a non-fuel region in sequence from inside to outside;
the fuel region comprises coated fuel particles and a graphite matrix;
the coated fuel particles are concentric UO from inside to outside in sequence 2 A core, a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB 2 A layer and an outer dense pyrolytic carbon layer;
wherein ZrB 2 Boron in the layer is 10 Enriched boron ZrB with B abundance of 60% 2 The coating thickness of the layer was 5 μm;
the coated fuel particles are dispersed in the graphite matrix.
The preparation method of the boron-containing spherical fuel element comprises the following steps:
(1) Preparation of UO by sol-gel process 2 A core: firstly 10g U 3 O 8 Mixing the raw material powder with nitric acid with the molar concentration of 16mol/L, and dissolving U by using the nitric acid 3 O 8 Raw material powder; then 5g of polyvinyl alcohol is added and mixed to obtain colloid; dispersing the obtained colloid into 10ml of 25% ammonia water to obtain gel particles; then aging, washing, drying and roasting at 600 ℃ for 1.5h to obtain UO 3 Particles; finally, reducing and sintering for 24 hours at 1600 ℃ to obtain compact UO 2 Ceramic particles of the UO 2 The diameter of the core is 0.50mm;
(2) Preparing coated fuel particles: depositing a loose pyrolytic carbon layer outside the fuel core by adopting a chemical vapor deposition method at 1250 ℃ for 30min; depositing the inner compact pyrolytic carbon layer at 1350 deg.c for 45min; then depositing a SiC layer for 5h at 1600 ℃; depositing ZrB at 1600 DEG C 2 Layer 2h; finally, depositing an outer compact pyrolytic carbon layer for 45min at 1350 ℃ to obtain coated fuel particles with the diameter of 1.0 mm;
(3) Preparing boron-containing spherical fuel elements: firstly, coating a layer of graphite powder on the surface of a coated fuel particle, and pressing to obtain a fuel area core sphere; then, a layer of graphite powder is pressed on the surface of the core ball of the fuel area to be used as a fuel-free area; carbonizing at 800 ℃ for 40h, turning, and purifying at 1200 ℃ for 15h to obtain the boron-containing spherical fuel element for the high-temperature gas-cooled reactor, wherein the boron-containing spherical fuel element comprises 10000 coated fuel particles.
In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. The boron-containing spherical fuel element for the high-temperature gas cooled reactor is characterized by comprising a fuel area and a fuel-free area from inside to outside in sequence;
the fuel region comprises coated fuel particles and a graphite matrix;
the coated fuel particles are concentric UO from inside to outside in sequence 2 A core, a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB 2 A layer and an outer dense pyrolytic carbon layer; wherein ZrB 2 The thickness of the layer is 5 to 20 μm;
the coated fuel particles are dispersed in the graphite matrix.
2. The boron-containing spherical fuel element for a high temperature gas-cooled reactor according to claim 1, wherein the ZrB is provided 2 The thickness of the layer is 10 to 15 μm.
3. The boron-containing spherical fuel element for a high temperature gas-cooled reactor according to claim 1 or 2, wherein ZrB is 2 The boron element in the layer is natural boron or enriched boron.
4. The boron-containing spherical fuel element for a high temperature gas-cooled reactor according to claim 1, wherein the number of the coated fuel particles in each of the boron-containing spherical fuel elements for a high temperature gas-cooled reactor is 10000 to 15000.
5. The boron-containing spherical fuel element for a high temperature gas-cooled reactor according to claim 1, wherein the UO is provided in a form of a spherical ball 2 The core is a round ball with the diameter of 0.5 mm.
6. The boron-containing spherical fuel element for a high temperature gas-cooled reactor according to claim 1, wherein the diameter of the cladding fuel particle is any one of 0.8mm, 0.92mm, or 1.0 mm.
7. The method for producing a boron-containing spherical fuel element for a high temperature gas-cooled reactor according to any one of claims 1 to 6, comprising the steps of:
(1) Preparation of UO by sol-gel process 2 A core: firstly, dissolving U by nitric acid 3 O 8 Adding organic binder into the raw material powder to obtain colloid, and dispersing the colloid into ammonia water to obtain gel particles; then aging, washing, drying and roasting are carried out to obtain UO 3 Particles; finally, the compact UO is obtained by reduction and sintering 2 Ceramic particles;
(2) Preparing coated fuel particles: depositing a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a SiC layer and ZrB outside the fuel core in sequence by adopting a chemical vapor deposition method 2 A layer and an outer dense pyrolytic carbon layer;
(3) Preparing boron-containing spherical fuel elements: firstly, coating a layer of graphite powder on the surface of a coated fuel particle, and pressing to obtain a fuel area core ball; then, a layer of graphite powder is pressed on the surface of the core ball of the fuel area to be used as a fuel-free area; and then carbonizing, turning and purifying at high temperature to obtain the boron-containing spherical fuel element.
8. The method for preparing the boron-containing spherical fuel element for the high-temperature gas-cooled reactor according to claim 7, wherein in the step (1), the roasting temperature is 500-600 ℃ and the roasting time is 1.5-2 h; the sintering temperature is 1550-1650 ℃, and the sintering time is 16-32 h.
9. The method according to claim 7, wherein in the step (2), the loose pyrolytic carbon layer is deposited by chemical vapor deposition at 1100-1300 ℃ for 10-30 min; carrying out chemical vapor deposition on the inner compact pyrolytic carbon layer for 15-45 min at the temperature of 1250-1500 ℃; carrying out chemical vapor deposition on the SiC layer for 2-5 h at 1450-1650 ℃; performing chemical vapor deposition of ZrB at 1450-1650 DEG C 2 Layer 1-2 h; carrying out chemical vapor deposition on the outer compact pyrolytic carbon layer for 15-45 min at the temperature of 1250-1500 ℃.
10. The method for preparing the boron-containing spherical fuel element for the high temperature gas-cooled reactor according to claim 7, wherein in the step (3), the carbonization temperature is 750-850 ℃ and the carbonization time is 30-50 h; the temperature of the high-temperature purification is 1150-1250 ℃, and the time is 10-20 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211181727.5A CN115547518A (en) | 2022-09-27 | 2022-09-27 | Boron-containing spherical fuel element for high-temperature gas cooled reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211181727.5A CN115547518A (en) | 2022-09-27 | 2022-09-27 | Boron-containing spherical fuel element for high-temperature gas cooled reactor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115547518A true CN115547518A (en) | 2022-12-30 |
Family
ID=84729603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211181727.5A Pending CN115547518A (en) | 2022-09-27 | 2022-09-27 | Boron-containing spherical fuel element for high-temperature gas cooled reactor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115547518A (en) |
-
2022
- 2022-09-27 CN CN202211181727.5A patent/CN115547518A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Demkowicz et al. | Coated particle fuel: Historical perspectives and current progress | |
| US10475543B2 (en) | Dispersion ceramic micro-encapsulated (DCM) nuclear fuel and related methods | |
| US3135665A (en) | Fuel element for a neutronic reactor | |
| CN108335760B (en) | Preparation method of high-uranium-loading-capacity dispersed fuel pellet | |
| KR101793896B1 (en) | Fully ceramic nuclear fuel and related methods | |
| US4597936A (en) | Lithium-containing neutron target particle | |
| US10109378B2 (en) | Method for fabrication of fully ceramic microencapsulation nuclear fuel | |
| US3992258A (en) | Coated nuclear fuel particles and process for making the same | |
| Gulden et al. | Preface: Coated particle fuels | |
| CN111724919A (en) | Coated fuel particle containing burnable poison coating layer, pellet, fuel element and preparation method thereof | |
| US4231976A (en) | Process for the production of ceramic plutonium-uranium nuclear fuel in the form of sintered pellets | |
| US20090268861A1 (en) | Plutonium/Zirconium Hydride/Thorium Fuel Matrix | |
| EP0015990B1 (en) | Nuclear fuel particles | |
| RU2427936C1 (en) | Combined pellet of nuclear fuel | |
| WO2024051678A1 (en) | Burnable poison coating and preparation method therefor, and nuclear fuel element | |
| CN115547518A (en) | Boron-containing spherical fuel element for high-temperature gas cooled reactor | |
| US3224944A (en) | Ceramic-matrix-type fuel element with graphite fabric affixed to exterior surface | |
| CN115547517A (en) | Gadolinium-containing spherical fuel element for high-temperature gas cooled reactor | |
| WO2020150976A1 (en) | Coated fuel particle, inert matrix dispersed fuel pellet and integrated fuel rod, and fabrication methods therefor | |
| US3301763A (en) | Method for preparing actinide oxide fuel particles and article thereof | |
| CN110828001B (en) | Heat conductivity improved uranium dioxide-based fuel pellet for improving uranium loading and preparation method thereof | |
| Stansfield | Evolution of HTGR coated particle fuel design | |
| JP7286680B2 (en) | fuel pellets | |
| USH259H (en) | Coated ceramic breeder materials | |
| CN112102968A (en) | High-thermal-conductivity fuel core block 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 |