CN115050499A - Full-ceramic coated fuel and preparation method thereof - Google Patents
Full-ceramic coated fuel and preparation method thereof Download PDFInfo
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Images
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C21/00—Apparatus or processes specially adapted to the manufacture of reactors or parts thereof
- G21C21/02—Manufacture of fuel elements or breeder elements contained in non-active casings
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
The invention discloses a full ceramic coating fuel and a preparation method thereof, wherein matrix ceramic particles and dispersed fuel particles are used as raw materials to prepare mixed powder; the mixed powder is taken as a raw material and is sequentially treated by a gel casting process and a sintering process to obtain the full-ceramic coated fuel; in the mixed powder, the content of dispersed fuel particles is 40 vol% -50 vol%. The invention effectively reduces the processing amount of the ceramic fuel element and solves the problem of complex structure fuel element preparation by a near net shape/high temperature sintering method.
Description
Technical Field
The invention relates to the technical field of dispersed fuel, in particular to the field of forming and preparation of ceramic fuel, and more particularly relates to full-ceramic-coated dispersed fuel applied to a nuclear reactor and a preparation method thereof.
Background
Improving the containment capacity of the fuel for fission products and fuel integrity is an important approach to improving reactor safety. Active UO 2 The fuel pellets have poor containment of fission products, are prone to cracking under normal operating temperature gradients, and undergo atypical interaction with cladding materials, resulting in fuel rod breakage and radioactive leakage. The international nuclear fuel field after the fukushima nuclear accident proposes a nuclear fuel development direction aiming at improving the capability of maintaining structural integrity of nuclear fuel in a severe environment.
In order to improve the capacity of the fuel to contain fission products, the full-ceramic-coated dispersion fuel is designed internationally. The fuel particle is formed by coating a fuel core surface with a multi-layer structure of loose pyrolytic carbon, compact pyrolytic carbon (IPyC, OPyC), SiC and the like to form a fuel particle (TRISO particle), and then dispersing the fuel particle in an external SiC matrix to finally form the full-ceramic coated dispersed fuel. Compared with the traditional UO 2 For ceramic fuels, a full ceramic-clad dispersion fuel has: first, the thermal conductivity is high. The thermal conductivity of the irradiated full-ceramic coated dispersion fuel can still reach UO 2 Twice as much fuel. Secondly, the fracture toughness is good, and the core block has better anti-cracking capability. The SiC matrix has higher fracture toughness, and can effectively prevent crack propagation. Third, excellent fission product containment. The multiple cladding structure and the SiC matrix material effectively prevent the release of radioactive fission products. Fourth, excellent radiation stabilityAnd (5) performing qualitative determination. The SiC matrix material has strong radiation swelling resistance and small radiation deformation of the full-ceramic coated dispersion fuel.
In addition, due to the excellent performance of the SiC matrix material in the full-ceramic coated dispersion fuel, such as excellent high-temperature oxidation resistance, ablation resistance, high melting point, higher high-temperature strength and the like, the SiC matrix has the characteristics of cladding and structural materials, so that the full-ceramic coated dispersion fuel has wide application prospect in an ultrahigh-temperature reactor. The ultra-high temperature reactor requires that the full ceramic coating dispersion fuel pellet has a complex structure, high content of TRISO particles and high substrate compactness.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the existing method for preparing the dispersed fuel is not suitable for preparing the all-ceramic coated dispersed fuel with a complex structure.
The invention is realized by the following technical scheme:
a method for preparing full ceramic coating fuel, using basal body ceramic particles and dispersion fuel particles as raw materials to prepare mixed powder; the mixed powder is taken as a raw material and is sequentially treated by a gel casting process and a sintering process to obtain the full-ceramic coated fuel; in the mixed powder, the content of dispersed fuel particles is 40 vol% -50 vol%. The high-dispersion fuel particle content is beneficial to improving the uranium loading of the fuel element, so that the service life of the fuel element is ensured, and the economical efficiency of the fuel element is improved. In the mixed powder, the content of the dispersed fuel particles is more preferably 45 vol% to 50 vol%.
Preparing mixed powder, preferably mixing by adopting a planetary ball milling mode, wherein a ball milling medium is absolute ethyl alcohol, and a mixing ball is a SiC ball (matrix ceramic particles are SiC particles); the ball-material ratio is designed to be 1:10, the mixing time is 2h-4h, then the mixed powder is poured out, and the mixed powder is dried for 2h in an air environment at the temperature of 60 ℃ to obtain uniform mixed powder.
Further optionally, a sintering aid is further added to the mixed powder.
The sintering aid is added in the powder mixing process, so that the dispersion of the sintering aid is facilitated, and meanwhile, the added sintering aid can improve the sintering density of the base material and is beneficial to improving the strength and the heat conductivity of the fuel element.
Further optionally, the sintering aid adopts Al 2 O 3 And Y 2 O 3 A mixture of (a); more preferably, Al 2 O 3 And Y 2 O 3 The mixture is used as a sintering aid when the molar ratio is 1.5-3.
The sintering aid is also B 4 C, etc., but Al 2 O 3 And Y 2 O 3 The mixture of (A) can better improve the compactness at lower sintering temperature.
Further optionally, the particle size of the matrix ceramic particles is 100nm or less.
Further optionally, the gel casting process comprises:
s11: preparing ceramic slurry: mixing the mixed powder with a dispersant, an organic monomer, a solvent and a cross-linking agent to obtain a suspension; adjusting the pH value of the suspension to 8-10 by adding NaOH; adding a defoaming agent to remove bubbles to obtain ceramic slurry;
s12: preparing a ceramic polymer colloid: adding a catalyst and an initiator into the ceramic slurry obtained in the step S11, and reacting to prepare a ceramic polymer colloid;
s13: preparing a green body: and (5) drying, demolding and removing the gel from the ceramic polymer gel obtained in the step (S12) to obtain a green body.
Preferably, the suspension is obtained by ball milling mixing, for example, the ball milling mixing time is about 4-6 h; the ceramic slurry is obtained by sieving and evenly mixed before defoaming, and then defoaming agent is added into the ceramic slurry for defoaming.
Further optionally, in step S11, the usage amount of each material is: 0.1 wt% -0.5 wt% of dispersing agent, 1 wt% -2 wt% of organic monomer, 40 vol% -60 vol% of solvent and 0.05 wt% -0.2 wt% of cross-linking agent.
Preferably, the dispersing agent includes, but is not limited to, polyvinylpyrrolidone, hydroxymethyl cellulose, methyl ammonium hydroxide, etc., the organic monomer includes, but is not limited to, N-methylolacrylamide, agar and hydroxypropyl methylcellulose, dimethyl acrylamide, the solvent includes, but is not limited to, t-butanol, toluene, and the cross-linking agent includes, but is not limited to, methylene bisacrylamide, etc. .
Preferably, the antifoaming agent includes, but is not limited to, n-butanol, added in an amount of 0.3ml to 0.5 ml. And (4) after adding the defoaming agent, removing bubbles in vacuum under the condition that the vacuum degree is lower than 1Pa to obtain the final ceramic slurry.
Further optionally, in step S12, the adding amount of the catalyst is 0.1 wt% to 0.2 wt%, and the adding amount of the initiator is 0.1 wt% to 0.3 wt%; the reaction temperature is 30-60 ℃.
Preferably, the catalyst includes, but is not limited to, tetramethylethylenediamine, sodium hexametaphosphate, and the like, and the initiator includes, but is not limited to, ammonium persulfate, span, and the like.
When preparing ceramic polymer colloid, adding catalyst and initiator (ammonium persulfate) into the obtained ceramic slurry, stirring, and pouring into a final mould, placing the mould in an air environment of 30-60 deg.C, and under the action of catalyst and initiator to obtain the polymer colloid.
Preferably, in step S13, the ceramic polymer colloid may be dried at a low temperature (e.g. 60 ℃) for 12 hours, and then removed from the mold to obtain a green body with a certain strength; and then carrying out glue discharging treatment on the green body in the air, and burning off organic substances in the green body, thereby obtaining the green body with certain strength and a complex structure.
Further optionally, in step S13, the glue discharging process is method (i) or method (ii) or method (iii);
method (i): placing the colloid in a muffle furnace for glue discharging, heating to 200-250 ℃ at a heating rate of 0.3-1 ℃/min, preserving heat for 30-60 min, heating to 550-650 ℃ at a heating rate of 0.5-1.5 ℃/min, preserving heat for 1-2 h, and cooling along with the furnace to obtain a green body;
method (ii): placing the colloid in a tube furnace, heating to 200-250 ℃ at a heating rate of 0.3-1 ℃/min, keeping the temperature for 30-60 min, introducing air into one side of the tube furnace at the same time, wherein the gas flow of the air is 200-300 ml/min, heating to 550-650 ℃ at a heating rate of 0.5-1.5 ℃/min, keeping the temperature for 1-2 h, and cooling along with the furnace to obtain a green body;
method (iii): carrying out high-temperature organic matter cracking in a vacuum furnace, placing the colloid in the vacuum furnace, heating to 500-550 ℃ at a heating rate of 0.5-1.5 ℃/min, preserving heat for 1.5-3 h, and then cooling along with the furnace; and then placing the cracked green body in a muffle furnace, heating to 600-650 ℃ at a heating rate of 0.5-1.5 ℃/min, preserving heat for 2-4h to discharge residual carbon after cracking, and then cooling to room temperature along with the furnace to obtain the green body.
Further optionally, the sintering process comprises: and placing the green body prepared by the gel film-injecting process in an air pressure sintering furnace or a vacuum furnace for air pressure or pressureless sintering treatment.
Can confirm atmospheric pressure or the technological parameter of pressureless sintering according to requirements such as the structure size of high density full ceramic cladding diffusion fuel component, ceramic matrix grain size, TRISO granule distribution state, the design of this application is:
the air pressure sintering process comprises the following steps: sintering atmosphere: n is a radical of 2 Or Ar, gas pressure: 3MPa-5 MPa. Heating the green body from room temperature to 900-1000 ℃ at a heating rate of 10-20 ℃, and preserving heat for 1-2 h; then heating to 1700-1800 ℃ at the heating rate of 10-15 ℃ and preserving heat for 2-4 h.
A pressureless sintering process: sintering atmosphere: n is a radical of 2 Or Ar protection, vacuum degree: < 1X 10 -2 Pa. The process flow is as follows: directly heating the green body from room temperature to 1000-1100 ℃ at the speed of 10-20 ℃/min, and keeping the temperature for 0.5-2 h; then heating to 2100 ℃ at a speed of 15-20 ℃/min, preserving heat for 2-4h, and then cooling to room temperature along with the furnace to finish sintering.
After the sintering treatment, the surface treatment of the sample can be sintered, and the surface treatment comprises grinding, polishing and the like. And (4) carrying out size measurement on the sintered dispersed fuel element, and grinding the sintered dispersed fuel element to a standard size. And then, carrying out surface polishing treatment on the dispersed fuel element by using sand paper until the surface has no obvious scratch, thereby obtaining a fuel element finished product.
The whole process of the preparation method of the all-ceramic coated fuel comprises the following steps: ceramic slurry, ceramic polymer colloid, green body preparation, sintering treatment and surface treatment.
The all-ceramic coated fuel is prepared by the preparation method of the all-ceramic coated fuel.
The invention has the following advantages and beneficial effects:
the full ceramic coated fuel is an important candidate fuel for an inherent safe high-temperature reactor due to the high heat dissipation area, the excellent irradiation stability, the excellent fission product containing capacity and the like. But the ceramic material has large forming, sintering and processing difficulties, and the fuel prepared by the prior art has simple structure and low density of the matrix, and can not meet the design requirement of a high-temperature reactor.
The invention solves the defects of the existing all-ceramic coated fuel preparation, including difficult preparation of fuel elements with complex structures, difficult densification of all-ceramic coated dispersed fuel, incapability of accurately controlling the size of a fuel-free area, difficult control of TRISO particle distribution and the like, through a near-net-shape/high-temperature sintering method.
The invention belongs to the preparation of near net shape of all-ceramic dispersion fuel elements, and ceramic slurry suitable for gel casting is obtained by optimizing the viscosity and solid content of the ceramic slurry; adding a cross-linking agent, an initiator and a catalyst to obtain a three-dimensional network polymer colloid; injecting colloid into a mold with a complex shape, and demolding to obtain a green body with a corresponding shape; finally, obtaining the dispersion fuel element with a complex shape through glue removal, high-temperature sintering and surface treatment. The gel casting method is adopted to prepare the high-density dispersion fuel element with the complex shape, so that the near-net forming and preparation of the ceramic fuel with the complex shape can be realized, the processing amount of the ceramic fuel element is effectively reduced, and the problem of preparing the fuel element with the complex structure is solved. The high-density full-ceramic-coated dispersion fuel element prepared by gel casting is suitable for preparing elements with complex structures, has simple production process and low cost, can realize large-scale industrial production, and has high density, high thermal conductivity and good toughness, and simultaneously has excellent thermal shock resistance, high-temperature oxidation resistance and ablation resistance.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a colloidal morphology of a ceramic polymer according to the present invention.
FIG. 2 is a graph of the viscosity of ceramic slurries of different solids contents in accordance with the present invention.
FIG. 3 is a topographical view of a green article after binder removal in accordance with the present invention.
FIG. 4 is a topographical view of a sintered all-ceramic dispersion fuel element in accordance with the present invention; wherein, 1-TRISO particles; 2-SiC matrix.
Fig. 5 is a macroscopic view of a sintered all-ceramic dispersion fuel element according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and the accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not used as limiting the present invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail so as not to obscure the present invention.
Throughout the specification, reference to "one embodiment," "an embodiment," "one example," or "an example" means: the particular features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the invention. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Example 1
The embodiment provides a ceramic slurry, which comprises the following specific steps:
step 1: preparation of the Mixed powder
And (3) ball-milling and mixing SiC particles (about 100nm), a sintering aid and TRISO particles.
Wherein, the usage of the sintering aid is 6 wt% based on the usage of the SiC particles; the sintering aid adopts Al 2 O 3 :Y 2 O 3 In terms of molar ratio, Al 2 O 3 :Y 2 O 3 ＝3:2。
The ball milling medium is absolute ethyl alcohol, the mixing balls are SiC balls, the ball-material ratio is 8:1, the mixing time is 8h, and then the mixed powder is obtained after drying at 60 ℃.
Step 2: preparation of ceramic slurry
And (2) ball-milling and mixing the mixed powder obtained in the step (1) with 0.2 wt% of polyvinylpyrrolidone, 1 wt% of N-methylolacrylamide, 40 vol% of tert-butyl alcohol and 0.1 wt% of methylene bisacrylamide to obtain a suspension, adding NaOH to adjust the pH to 10, and filtering by using a 200-mesh sieve to obtain suspension slurry.
Wherein, the addition amounts of the polyvinylpyrrolidone, the N-hydroxymethyl acrylamide, the tert-butyl alcohol and the methylene bisacrylamide are calculated by taking the amount of the mixed powder as a reference.
According to the above method, the amounts of TRISO particles used were designed to be 45 vol%, 50 vol%, 55 vol%, and 60 vol%, respectively.
And (3) carrying out viscosity test on the ceramic slurry:
the test method comprises the following steps: the viscosity of the slurry is measured by a viscometer, the viscosity meter is a Brookfield standard, a No. 2-4 rotor is adopted for viscosity measurement, and the rotating speed is 30-90 rmp.
The test results are shown in fig. 2.
Example 2
The embodiment provides a full-ceramic coated fuel and a preparation method thereof, which specifically comprise the following steps:
step 1: preparation of the Mixed powder
And (3) ball-milling and mixing SiC particles (about 100nm), a sintering aid and TRISO particles.
Wherein, based on the usage of SiC particles, the usage of the sintering aid is 6 wt%, and the usage of the TRISO particles is 45 vol%; the sintering aid adopts Al 2 O 3 :Y 2 O 3 In terms of molar ratio, Al 2 O 3 :Y 2 O 3 ＝3:2。
The ball milling medium is absolute ethyl alcohol, the mixing balls are SiC balls, the ball-material ratio is 8:1, the mixing time is 8h, and then the mixed powder is obtained after drying at 60 ℃.
And 2, step: preparation of ceramic slurry
And (2) ball-milling and mixing the mixed powder obtained in the step (1) with 0.2 wt% of polyvinylpyrrolidone, 1 wt% of N-methylolacrylamide, 40 vol% of tert-butyl alcohol and 0.1 wt% of methylene bisacrylamide to obtain a suspension, adding NaOH to adjust the pH to 10, and filtering by using a 200-mesh sieve to obtain suspension slurry.
Wherein, the addition amounts of the polyvinylpyrrolidone, the N-hydroxymethyl acrylamide, the tert-butyl alcohol and the methylene bisacrylamide are calculated by taking the amount of the mixed powder as a reference.
And step 3: preparation of ceramic Polymer colloids
Dropwise adding 5 drops of n-butanol into the ceramic slurry prepared in the step 2, and keeping the mixture for 1 hour in an environment with the vacuum degree of 0.5 Pa; then, adding 0.1 wt% of tetramethylethylenediamine and 0.3 wt% of ammonium persulfate into the suspension, uniformly stirring, pouring into a forming mold, placing the mold in an oven at 50 ℃, preserving heat for 8 hours, and demolding to obtain the colloid with the complex shape.
And 4, step 4: preparation of the Green bodies
And (3) placing the colloid prepared in the step (3) in a muffle furnace for glue discharging, heating to 200 ℃ at a heating rate of 0.5 ℃/min, preserving heat for 30min, heating to 550 ℃ at a heating rate of 1 ℃/min, preserving heat for 1h, and cooling along with the furnace to obtain a green body with certain strength and a complex structure.
And 5: sintering treatment
The method for preparing the high-density complex-structure all-ceramic-coated dispersion fuel element by adopting air pressure sintering comprises the following specific steps:
and placing the green body after the rubber is removed in a graphite mold, placing the graphite mold in an air pressure sintering furnace, vacuumizing the air pressure furnace, filling high-purity Ar gas into the furnace to 3MPa when the vacuum degree reaches below 0.1Pa, and keeping other pressure not to exceed 10Pa all the time. Heating to 1000 ℃ at a heating rate of 10 ℃/min, preserving heat for 1h, heating to 1800 ℃ at a heating rate of 10 ℃/min, preserving heat for 4h, and cooling with the furnace to obtain the compact diffusion fuel element.
Step 6: surface treatment
And (5) polishing the sintered sample in the step 5 by using 800, 1000 and 1200-mesh carborundum water sandpaper until the surface has no obvious scratches to obtain a finished fuel element.
Example 3
The difference between this embodiment and embodiment 2 is that the process parameters of green body preparation and sintering in this embodiment are different, and are specifically set as follows:
(a) when the rubber discharge adopts a tube furnace, the rubber discharge process is as follows:
placing the colloid in a tube furnace, heating to 200 ℃ at a heating rate of 0.5 ℃/min, preserving heat for 30min, simultaneously introducing air into one side of the tube furnace, wherein the gas flow of the air is 200ml/min, then heating to 550 ℃ at a heating rate of 0.5 ℃/min, preserving heat for 1h, and then cooling along with the furnace to obtain a green body with a certain strength and a complex structure.
(b) When the two-step glue discharging process is adopted, the glue discharging process is as follows:
firstly, carrying out high-temperature organic matter cracking in a vacuum furnace, placing colloid in the vacuum furnace, heating to 600 ℃ at a heating rate of 1 ℃/min, preserving heat for 2h, and then cooling along with the furnace; and then placing the cracked green body in a muffle furnace, heating to 600 ℃ at a heating rate of 1 ℃/min, preserving heat for 2h to discharge residual carbon after cracking, and then cooling to room temperature along with the furnace to obtain the green body with a certain strength and a complex structure.
(c) When the sintering mode is pressureless sintering, the sintering process is as follows:
and placing the green body after the rubber removal into a mold, and sintering under no pressure. The sintering temperature is 2100 ℃, and the sintering environment is as follows: vacuum sintering, the heat preservation time is 6h, and the vacuum degree is as follows: < 1X 10 -2 Pa. The process flow is as follows: heating to 1000 ℃ at a speed of 15 ℃/min, and keeping the temperature for 1 h; heating to 2100 ℃ at the temperature of 15 ℃/min, preserving heat for 4h, and then cooling to room temperature along with the furnace to obtain the fuel element with the complex structure. The preparation results are shown in fig. 5. The properties of the finished product in the above example were tested.
The detection method comprises the following steps:
the thermal conductivity was measured using a laser thermal conductivity meter: and (4) measuring the temperature difference of the two surfaces of the sample at different temperatures respectively, and calculating the thermal conductivity of the material.
The density is measured by a drainage method: the samples were weighed in air and water, respectively, after which the sample density was calculated according to archimedes' law.
The ablation resistance is measured by an oxyacetylene flame method, and the mass loss at different times is measured as follows: firstly weighing the original mass of a sample, blowing the sample in air by using oxyacetylene flame, wherein the heat flow density of the oxyacetylene flame is 15kW/cm, weighing the mass of the sample after the sample is cooled to room temperature after blowing for different times, and calculating the ablation rate at different times.
The thermal shock resistance is tested by adopting a high-temperature heating-water quenching mode: the sample is heated to 1100 ℃ in a muffle furnace, then the sample is taken out, the sample is quickly placed in boiling water, and then the appearance quality of the sample is observed, so that the thermal shock performance of 1000 ℃ is obtained.
The results are shown in Table 1.
As can be seen from table 1, the method of the present invention not only can effectively overcome the problems of complicated steps, difficult densification of complex structures, difficult molding of complex structures, difficult preparation of fuel-free areas, etc. in the existing preparation of the all-ceramic coated dispersed fuel, but also has the advantages of simple production process, low cost, short production period, suitability for industrial production, etc.; and the prepared finished product has the advantages of high thermal conductivity, high density, high thermal shock resistance, high ablation resistance, strong capability of containing cracked products and the like, and can meet the requirements of a high-temperature reactor.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A preparation method of full ceramic coating fuel is characterized in that matrix ceramic particles and dispersion fuel particles are used as raw materials to prepare mixed powder; the mixed powder is taken as a raw material and is sequentially treated by a gel casting process and a sintering process to obtain the full-ceramic coated fuel; in the mixed powder, the content of dispersed fuel particles is 40 vol% -50 vol%.
2. The method for preparing the all-ceramic coated fuel according to claim 1, wherein a sintering aid is further added to the mixed powder.
3. The method of claim 1, wherein the sintering is performed in a manner that the fuel is fully ceramic coatedThe auxiliary agent adopts Al 2 O 3 And Y 2 O 3 A mixture of (a).
4. The method of claim 1, wherein the size of the matrix ceramic particles is less than or equal to 100 nm.
5. The method for preparing an all-ceramic coated fuel according to any one of claims 1 to 4, wherein the gel casting process comprises:
s11: preparing ceramic slurry: mixing the mixed powder with a dispersant, an organic monomer, a solvent and a cross-linking agent to obtain a suspension; adjusting the pH value of the suspension to 8-10 by adding NaOH; adding a defoaming agent to remove bubbles to obtain ceramic slurry;
s12: preparing a ceramic polymer colloid: adding a catalyst and an initiator into the ceramic slurry obtained in the step S11, and reacting to prepare a ceramic polymer colloid;
s13: preparing a green body: and (5) drying, demolding and removing the gel from the ceramic polymer gel obtained in the step (S12) to obtain a green body.
6. The method for preparing the all-ceramic coated fuel according to claim 5, wherein in the step S11, the dosage of each material is as follows: 0.1 wt% -0.5 wt% of dispersing agent, 1 wt% -2 wt% of organic monomer, 40 vol% -60 vol% of solvent and 0.05 wt% -0.2 wt% of cross-linking agent.
7. The method of claim 5, wherein in step S12, the catalyst is added in an amount of 0.1 wt% to 0.2 wt%, and the initiator is added in an amount of 0.1 wt% to 0.3 wt%; the reaction temperature is 30-60 ℃.
8. The method for preparing the all-ceramic coated fuel according to claim 5, wherein in step S13, the gel discharging process is method (i) or method (ii) or method (iii);
method (i): placing the colloid in a muffle furnace for glue discharging, heating to 200-250 ℃ at a heating rate of 0.3-1 ℃/min, preserving heat for 30-60 min, heating to 550-650 ℃ at a heating rate of 0.5-1.5 ℃/min, preserving heat for 1-2 h, and cooling along with the furnace to obtain a green body;
method (ii): placing the colloid in a tube furnace, heating to 200-250 ℃ at a heating rate of 0.3-1 ℃/min, keeping the temperature for 30-60 min, introducing air into one side of the tube furnace at the same time, wherein the gas flow of the air is 200-300 ml/min, heating to 550-650 ℃ at a heating rate of 0.5-1.5 ℃/min, keeping the temperature for 1-2 h, and cooling along with the furnace to obtain a green body;
method (iii): cracking the high-temperature organic matters in a vacuum furnace, placing the colloid in the vacuum furnace, heating to 500-550 ℃ at a heating rate of 0.5-1.5 ℃/min, keeping the temperature for 1.5-3 h, and then cooling along with the furnace; and then placing the cracked green body in a muffle furnace, heating to 600-650 ℃ at a heating rate of 0.5-1.5 ℃/min, preserving heat for 2-4h to discharge residual carbon after cracking, and then cooling to room temperature along with the furnace to obtain the green body.
9. The method for preparing the all-ceramic coated fuel according to claim 1, wherein the sintering process comprises: and (3) placing the green body prepared by the gel film-injecting process in an air pressure sintering furnace or a vacuum furnace for air pressure or pressureless sintering treatment.
10. An all-ceramic coated fuel, which is prepared by the preparation method of the all-ceramic coated fuel as claimed in any one of claims 1 to 9.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017016079A1 (en) * | 2015-07-28 | 2017-02-02 | 山东合创明业精细陶瓷有限公司 | Method for synthesizing high-purity ultrafine zrc-sic composite powder |
| CN107180654A (en) * | 2017-05-27 | 2017-09-19 | 中国工程物理研究院材料研究所 | A kind of MAX phase ceramics matrix disperse pellet nuclear fuel and its preparation method and purposes |
| KR20170130778A (en) * | 2016-05-19 | 2017-11-29 | 주식회사 맥테크 | The manufacturing method of ceramic molded object using gel casting |
| CN107578837A (en) * | 2017-10-16 | 2018-01-12 | 中国核动力研究设计院 | The method that integrated molding prepares the full ceramic coatings fuel pellet of tabular |
-
2022
- 2022-06-27 CN CN202210736494.4A patent/CN115050499A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017016079A1 (en) * | 2015-07-28 | 2017-02-02 | 山东合创明业精细陶瓷有限公司 | Method for synthesizing high-purity ultrafine zrc-sic composite powder |
| KR20170130778A (en) * | 2016-05-19 | 2017-11-29 | 주식회사 맥테크 | The manufacturing method of ceramic molded object using gel casting |
| CN107180654A (en) * | 2017-05-27 | 2017-09-19 | 中国工程物理研究院材料研究所 | A kind of MAX phase ceramics matrix disperse pellet nuclear fuel and its preparation method and purposes |
| CN107578837A (en) * | 2017-10-16 | 2018-01-12 | 中国核动力研究设计院 | The method that integrated molding prepares the full ceramic coatings fuel pellet of tabular |
Non-Patent Citations (1)
| Title |
|---|
| 宋彤: ""嬗变次锕系核素的弥散型核燃料的设计与制备研究"", 《中国博士学位论文全文数据库 工程科技Ⅱ辑》, 15 January 2021 (2021-01-15), pages 12 - 16 * |
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