Neutron-absorbing material and its application, Control rod for nuclear reactor core

Abstract

The application relates to a neutron absorption material and application thereof to a control rod for a nuclear reactor core. The neutron absorption material provided by the application is prepared by mixing ytterbium elements and holmium elements in a certain proportion, can effectively play the high neutron capture cross-section characteristics of the ytterbium elements and the holmium elements, effectively absorb thermal neutrons, and can ensure good chemical and thermal stability, so that the neutron absorption material can maintain its structure and performance stability for a long time in a high irradiation environment, effectively avoids the conversion of the neutron absorption material into a weak neutron absorption material after absorbing neutrons, and further controls the neutron absorption characteristics of the neutron absorption material. Further, the neutron absorption material provided by the application can still ensure the neutron absorption characteristics thereof and maintain the reactivity value under high burnup depth, so as to prolong the service life of the control rod for the nuclear reactor core.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear reactor neutron absorption material, in particular to a neutron absorption material and application thereof, and a control rod for nuclear reactor core. BACKGROUND

[0002] Generally, the power level and the primary loop average temperature of a nuclear power plant are controlled by adjusting the control rod position or adjusting the concentration of boric acid. Although the chemical compensation method of changing the concentration of boric acid for controlling reactivity is relatively stable and uniform, the control of reactivity by adjusting the concentration of boric acid is slow and a large amount of boric acid-containing wastewater is generated. Therefore, at present, the insertion and extraction of control rods are mainly used to achieve rapid reactivity control of the core.

[0003] The neutron absorption material in the control rod is an important component for realizing the power level control and the primary loop average temperature control of the nuclear reactor. The neutron absorption material needs to be inserted into the core active region for a long time to control the changes of the burnup reactivity, the xenon-induced reactivity and the temperature reactivity in the reactor. Therefore, the neutron absorption material is easily irradiated by the high neutron flux in the core active region. At present, the widely used neutron absorption material is Ag-In-Cd, but the reactivity value of the Ag-In-Cd neutron absorption material decreases rapidly with burnup, which cannot guarantee the sufficient service life of the neutron absorption body under the condition of the core active section. SUMMARY

[0004] Based on this, the present application provides a neutron absorption material and application thereof, and a control rod for nuclear reactor core. The neutron absorption material provided by the present application can still guarantee the neutron absorption characteristics, maintain the reactivity value and prolong the service life of the control rod for nuclear reactor core under high burnup depth.

[0005] In a first aspect of the present application, a neutron absorption material is provided, and the components of the neutron absorption material include ytterbium and holmium with a mass ratio of (0.7-0.95): 1.

[0006] In one of the embodiments, the components of the neutron absorption material include a first component, a second component and a third component, and the mass ratio of the first component, the second component and the third component is (0.7-0.95): 1: (0.4-4).

[0007] The first component includes ytterbium and / or ytterbium oxide.

[0008] The second component includes holmium and / or holmium oxide.

[0009] The third component includes one or more of molybdenum, molybdenum oxide, AlN, yttrium, yttrium oxide and calcium oxide.

[0010] In one of the embodiments, the mass percentage of the ytterbium element in the neutron absorption material is 7% to 15%.

[0011] In one of the embodiments, the mass ratio of the first component, the second component and the third component is (0.7 to 0.95):1:(0.4 to 1).

[0012] In one of the embodiments, the mass percentage of the ytterbium element in the neutron absorption material is 10% to 15%.

[0013] In one of the embodiments, the oxide of the ytterbium includes Yb2O3, and / or the oxide of the holmium includes Ho2O3.

[0014] In one of the embodiments, the mass percentage of the holmium element in the neutron absorption material is 7% to 21%.

[0015] In one of the embodiments, the neutron absorption property of the neutron absorption material is ≥ 90% under the condition of the burnup depth of 70 GWd / tU.

[0016] In the second aspect of the present application, a control rod for a nuclear reactor core is provided, which includes a cladding and a neutron absorption material filled in the inside of the cladding, and the neutron absorption material is the neutron absorption material according to any one of the embodiments of the first aspect of the present application.

[0017] In the third aspect of the present application, the neutron absorption material according to any one of the embodiments of the first aspect of the present application is used as a high-temperature gas-cooled reactor control rod and a shielding body ceramic material.

[0018] The neutron absorption material provided in the present application is prepared by compounding the ytterbium element and the holmium element in a certain proportion, which can effectively play the high neutron capture cross-section characteristics of the ytterbium element and the holmium element, effectively absorb thermal neutrons, and ensure good chemical and thermal stability, so that the structure and performance of the neutron absorption material can be kept stable for a long time in a high irradiation environment, effectively avoiding the conversion of the neutron absorption material into a weak neutron absorption material after absorbing neutrons, and further avoiding the influence on the neutron absorption property of the neutron absorption material.

[0019] Further, the neutron absorption material provided in the present application can still ensure the neutron absorption property under high burnup depth, maintain the reactivity value, and prolong the service life of the control rod for the nuclear reactor core. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The neutron absorption property curve of the neutron absorption material of Example 1 to Example 4 and Comparative Example 1 of the present application under the condition of the burnup depth of 0 GWd / tU to 70 GWd / tU is shown in the following figure. DETAILED DESCRIPTION

[0021] The neutron-absorbing material and its application, and the control rod for nuclear reactor core are further fully and clearly described below in connection with specific embodiments. The present application can be realized in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0022] When a numerical range is disclosed herein, the range is to be construed as continuous along the entire range, and inclusive of the minimum and maximum values of the range, as well as each integer within the range. Further, where a range is provided, it is intended to encompass any and all sub-ranges of the range. In other words, unless otherwise specifically stated herein, all ranges disclosed herein are to be understood to be inclusive of the end points of the ranges.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in describing the application herein are to be interpreted under the broadest possible term as is allowed under the circumstances. It will be further understood that the use of relating terms or phrases are used herein not to limit but to describe certain specific embodiments, it being understood that many variations are possible.

[0024] In the present application, the terms "a plurality of", "a plurality of kinds", "a plurality of times", "a plurality of elements" and the like, if not otherwise specified, refer to more than two or equal to two in number. For example, "one or more" means one or more than two.

[0025] In the present application, the terms "first", "second", "third", "fourth" and the like in the "first aspect", "second aspect", "third aspect", "fourth aspect" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or quantity, nor can it be understood as implying the importance or quantity of the technical features indicated. Moreover, "first", "second", "third", "fourth" and the like only serve the purpose of non-exhaustive enumeration and description, and should be understood as not constituting a closed limitation on the quantity.

[0026] In the present application, the technical features described in an open manner include both the closed technical solution consisting of the listed features and the open technical solution containing the listed features.

[0027] In the present application, the terms "preferably", "more preferably", "even more preferably", "suitably" only describe the embodiments or examples with better effects, and should be understood as not constituting a limitation on the scope of protection of the present application.

[0028] In the present application, "further", "furthermore", "in particular" and the like are used for the purpose of description, and represent differences in content, but should not be understood as limiting the scope of protection of the present application.

[0029] In the present application, "optionally", "optional" and "may" mean that it can or can not exist, that is, it means to select any one from the two parallel schemes of "yes" or "no". If there are multiple "options" in a technical solution, unless otherwise specified, and there is no contradiction or mutual restriction, each "option" is independent.

[0030] In the present application, the numerical interval (i.e. the numerical range) is not specified, and the optional numerical distribution within the above numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e. the minimum value and the maximum value) of the numerical range, and each numerical value between the two numerical endpoints. If not specified, when the numerical interval only refers to the integers within the numerical interval, including the two endpoint integers of the numerical range and each integer between the two endpoints, in this article, it is equivalent to directly listing each integer, such as t is an integer selected from 1-10, which means that t is any integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. In addition, when multiple ranges are provided to describe characteristics or properties, these ranges can be combined. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0031] The temperature parameter in the present application, unless otherwise specified, allows for constant temperature treatment, and also allows for fluctuations within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. It is allowed to fluctuate within the range of, for example, ±5℃, ±4℃, ±3℃, ±2℃, ±1℃.

[0032] In the present application, the percentage concentration refers to the final concentration, unless otherwise specified. The final concentration refers to the proportion of the added ingredient in the system after the ingredient is added.

[0033] In the present application, the "neutron absorption characteristic" is the ratio of the reactivity value of the neutron absorption material considering the burnup calculation of the absorber to the reactivity value without considering the burnup calculation. This ratio can intuitively show the neutron absorption characteristic of the neutron absorber in the control rod, and if the ratio is closer to 1, it means that the reactivity value of the control rod is closer to constant when the burnup is considered.

[0034] The control rod is made of neutron-absorbing material, which can absorb a large number of neutrons to prevent the fission chain reaction of the nuclear reactor when the control rod is inserted into the fuel assembly for control adjustment. However, as the insertion time of the neutron-absorbing material of the control rod in the fuel assembly increases, the neutron-absorbing material itself will also absorb neutrons for burnup, which will cause the neutron-absorbing material to be converted into weak neutron-absorbing material, reducing the neutron-absorbing property of the neutron-absorbing material.

[0035] Based on this, the first aspect of the present application provides a kind of neutron-absorbing material, including mass ratio of (0.7~0.95): 1 Ytterbium element and holmium element.

[0036] It can be understood that the mass ratio of ytterbium element and holmium element in the present application can be selected from any value between (0.7~0.95): 1. Specifically, the mass ratio of ytterbium element and holmium element includes but is not limited to 0.7: 1, 0.71: 1, 0.72: 1, 0.73: 1, 0.75: 1, 0.78: 1, 0.8: 1, 0.81: 1, 0.82: 1, 0.83: 1, 0.85: 1, 0.88: 1, 0.89: 1, 0.9: 1, 0.91: 1, 0.92: 1, 0.93: 1, 0.94: 1 or 0.95: 1. The neutron-absorbing material provided by the present application can effectively play the high neutron capture cross-section characteristics of ytterbium element and holmium element by compounding ytterbium element and holmium element in a mass ratio of (0.7~0.95): 1, thereby effectively absorbing thermal neutrons, ensuring better chemical and thermal stability, and thereby maintaining the structure and performance stability for a long time in a high irradiation environment, effectively avoiding the conversion of the material into weak neutron-absorbing material after absorbing neutrons, and thereby avoiding the impact on the neutron-absorbing property of the material.

[0037] Further, the neutron-absorbing material provided by the present application can still ensure the neutron-absorbing property thereof at a high burnup depth, maintain the reactivity value, and prolong the service life of the neutron-absorbing body.

[0038] In one example, the components of the neutron-absorbing material include a first component, a second component and a third component, and the mass ratio of the first component, the second component and the third component is (0.7~0.95): 1: (0.4~4).

[0039] The first component includes ytterbium element and / or ytterbium oxide;

[0040] The second component includes holmium element and / or holmium oxide;

[0041] The third component includes one or more of molybdenum element, molybdenum oxide, AlN, yttrium element, yttrium oxide and calcium oxide.

[0042] It can be understood that the mass ratio of the ytterbium element and / or the oxide of ytterbium, the holmium element and / or the oxide of holmium, and the third component in the present application can be selected from any value between (0.7-0.95):1:(0.4-4). Specifically, the ratio of the ytterbium element and / or the oxide of ytterbium, the holmium element and / or the oxide of holmium, and the third component includes but is not limited to 0.7:1:0.4, 0.71:1:0.8, 0.72:1:1, 0.76:1:1, 0.8:1:2, 0.85:1:2.5, 0.9:1:3, 0.9:1:3.5, or 0.95:1:4.

[0043] The elements and compounds in the third component have weak neutron absorption relative to the ytterbium element and the holmium element, thereby avoiding affecting the stable absorption characteristics of the Yb / Ho ratio. At the same time, the addition of the third component can effectively adjust the mass percentage of the ytterbium element in the neutron absorption material, so that the neutron absorption material has good radiation resistance, effectively reduces or inhibits material damage and degradation caused by radiation, improves the reliability of the neutron absorption material under high radiation, and prolongs the service life of the control rod for nuclear reactors.

[0044] In addition, among the molybdenum element, the oxide of molybdenum, AlN, the yttrium element, and the oxide of yttrium included in the third component, the oxide of molybdenum includes but is not limited to MoO2 and MoO3; and the oxide of yttrium includes but is not limited to Y2O3.

[0045] In one example, the mass percentage of the ytterbium element in the neutron absorption material is 7%-15%. It can be understood that the mass percentage of the ytterbium element in the neutron absorption material can be selected from any value between 7% and 15%. Specifically, the mass percentage of the ytterbium element in the neutron absorption material includes but is not limited to 7%, 8%, 10%, 12%, 14%, or 15%. By limiting, the mass percentage of the ytterbium element in the neutron absorption material can optimize the burnup depth of the neutron absorption material, so that it can still maintain a high neutron absorption characteristic after use, thereby prolonging the service life of the neutron absorption material and improving its use efficiency.

[0046] Preferably, the mass ratio of the first component, the second component, and the third component is (0.7-0.95):1:(0.4-1). By further adjusting the weight ratio of the first component, the second component, and the third component, the material can be further avoided from being converted into a weak neutron absorption material after absorbing neutrons, the neutron absorption characteristics can be controlled, the neutron absorption characteristics under high burnup depth can be further improved, the reactivity value can be effectively maintained, and the service life can be prolonged.

[0047] Preferably, the mass percentage of the ytterbium element in the neutron absorption material is 10% to 15%. Preferably, the mass percentage of the ytterbium element is in this range, which can further optimize the burnup depth of the neutron absorption material, i.e. prolong the service life of the material, thereby achieving higher burnup efficiency, reducing the decay loss of the material, and making the neutron absorption property ≥ 97%, thereby prolonging the reliable use time of the neutron absorption body.

[0048] In one example, the oxide of ytterbium includes Yb2O3. Ytterbium oxide has strong resistance to ionizing radiation and can withstand the radiation environment in the nuclear reactor while maintaining its performance and stability. In addition, it should be understood that the chemical formula of "ytterbium oxide" mentioned in the present application is Yb2O3.

[0049] In one example, the oxide of holmium includes Ho2O3. It should be understood that the chemical formula of "holmium oxide" mentioned in the present application is Ho2O3.

[0050] More preferably, in the neutron absorption material according to the present application, the components of the neutron absorption material include ytterbium element and / or ytterbium oxide, holmium element and / or holmium oxide, and a third component, with a mass ratio of (0.7-0.95):1:(0.4-1); and the mass percentage of the ytterbium element in the neutron absorption material is 10% to 15%. The neutron absorption material satisfying the above two mass ratios can adjust the function and performance of the neutron absorption material, so that the neutron absorption property decreases slowly with the increase of the burnup depth, and can effectively ensure that the neutron absorption property of the neutron absorption material is ≥ 97%, thereby prolonging the reliable use time of the neutron absorption body.

[0051] In one example, the neutron absorption property of the neutron absorption material is ≥ 90% under the condition that the burnup depth is 70 GWd / tU.

[0052] A nuclear reactor, also known as an atomic energy reactor or a reactor, is a device that can maintain a controllable self-sustaining chain nuclear fission reaction to achieve nuclear energy utilization. The nuclear reactor can maintain a self-sustaining chain nuclear fission reaction by arranging nuclear fuel reasonably, without the need for additional neutron sources; the nuclear reactor includes a pressurized water reactor, a boiling water reactor, a heavy water reactor, and a fast reactor, etc. Different reactors have different control rod shapes and sizes. Among them, the heavy water reactor uses a control rod in the form of a thick rod or a sleeve, the boiling water reactor uses a cross-shaped control rod, the pressurized water reactor uses a bundle rod control rod, and usually includes 24 very thin control rods.

[0053] Based on this, the second aspect of the present application provides a control rod for nuclear reactor core, comprising a cladding and a neutron absorbing material filled in the cladding. The neutron absorbing material is the neutron absorbing material described in any one of the examples of the second aspect of the present application. It can be understood that the present application mainly considers the components of the control rod for nuclear reactor core, and does not limit the specific shape of the control rod for nuclear reactor core.

[0054] The control rod for nuclear reactor core provided by the present application can still guarantee the neutron characteristics and maintain the reactivity value at high burnup depth, thereby prolonging the service life of the neutron absorber. In addition, it can be understood that the control rod for nuclear reactor core in the present application has all the advantages of the neutron absorbing material described in any one of the examples of the first aspect of the present application, which will not be repeated here. The control rod for nuclear reactor core in the present application is made of the neutron absorbing material described in any one of the examples of the first aspect, and there is a set of mechanical devices outside the nuclear reactor pressure vessel to manipulate the control rod. When the control rod is completely inserted into the center of the reactor, it can absorb a large number of neutrons to weaken the progress of the fission chain reaction. If the control rod is pulled out a little, the speed of the chain reaction gradually reaches a certain stable value. If you want to increase the energy released by the reactor, you only need to pull out the control rod a little more, so that the absorbed neutrons decrease, and more neutrons participate in the fission reaction. Inserting the control rod completely into the nuclear reaction center to absorb most of the neutrons can stop the progress of the chain reaction. Further, the control rod for nuclear reactor core provided by the present application can effectively avoid being converted into a weak neutron absorbing material after absorbing neutrons, thereby controlling the neutron characteristics of the control rod, so that it can still guarantee the neutron characteristics and maintain the reactivity value at high burnup depth, thereby prolonging the service life of the neutron absorber.

[0055] The following specific examples are provided to further illustrate the present application, but the present application is not limited to the following examples. Unless otherwise specified, the raw materials used in the examples are commercially available products.

[0056] Example 1

[0057] The example 1 of the present application provides a kind of neutron absorbing material, including Yb2O3, Ho2O3 And MoO3. Wherein, Yb2O3 is 9.44 parts, Ho2O3 is 10 parts, MoO3 is 8.2 parts by weight fraction. Wherein, the mass ratio of Yb2O3 And Ho2O3 It is 0.944:1, and the mass ratio of ytterbium element and holmium element is 0.95:1;In the neutron absorbing material of example 1, the mass percentage of Yb2O3 It is 34.2%, and the mass percentage of the ytterbium element in the neutron absorbing material is 15%.

[0058] Example 2

[0059] Embodiment 2 of the present application provides a kind of neutron absorption material, including Yb2O3, Ho2O3And MoO3.Therein, Yb2O3 7.36 parts, Ho2O3 10 parts, MoO3 4.18 parts by weight portion.Therein, the mass ratio of Yb2O3 And Ho2O3 It is 0.736:1, the mass ratio of ytterbium element and holmium element is 0.74:1;In the neutron absorption material of embodiment 2, the mass percentage of Yb2O3 It is 34.2%, the mass percentage of the ytterbium element in the neutron absorption material is 15%.

[0060] Embodiment 3

[0061] Embodiment 3 of the present application provides a kind of neutron absorption material, including Yb2O3, Ho2O3And MoO3.Therein, Yb2O3 9.44 parts, Ho2O3 10 parts, MoO3 39.8 parts by weight portion.Therein, the mass ratio of Yb2O3 And Ho2O3 It is 0.944:1, the mass ratio of ytterbium element and holmium element is 0.95:1;In the neutron absorption material of embodiment 3, the mass percentage of Yb2O3 It is 16%, the mass percentage of the ytterbium element in the neutron absorption material is 7%.

[0062] Embodiment 4

[0063] Embodiment 4 of the present application provides a kind of neutron absorption material, including Yb2O3, Ho2O3And MoO3.Therein, Yb2O3 7.36 parts, Ho2O3 10 parts, MoO3 28.8 parts by weight portion.Therein, the mass ratio of Yb2O3 And Ho2O3 It is 0.736:1, the mass ratio of ytterbium element and holmium element is 0.74:1;In the neutron absorption material of embodiment 4, the mass percentage of Yb2O3 It is 16%, the mass percentage of the ytterbium element in the neutron absorption material is 7%.

[0064] Comparative Example 1

[0065] Comparative Example 1 of the present application provides a kind of neutron absorption material, including metal Ag, metal In and metal Cd.Therein, the mass ratio of metal Ag, metal In and metal Cd is 80:15:5.

[0066] The mass ratio of the content of each component in embodiment 1~embodiment 4 and comparative example 1 is as shown in table 1.

[0067] Table 1

[0068]

[0069] Test method: The neutron absorbing materials in examples 1-4 and comparative example 1 are modeled by Monte Carlo program according to the mass ratio, and the burnup calculation can use Chebyshev rational approximation method, as shown in the paper (Value loss of gray control rod calculated and analyzed by RMC program, Modern Applied Physics, 2020, 11 (01)).

[0070] The test results of the neutron absorption characteristics of the neutron absorbing materials in examples 1-4 and comparative example 1 at the burnup depth of 0 GWd / tU-70 GWd / tU are shown in Figure 1 Figure 1 In particular, the y-axis is the ratio of the reactivity value of the control rod absorbing body material considering the burnup calculation to the reactivity value without considering the burnup calculation. This ratio can directly show the neutron absorption characteristics of the control rod neutron absorber. If the ratio is closer to 1, it means that the reactivity value of the control rod is closer to constant during burnup. In comparative example 1, the neutron absorption characteristics of the Ag-In-Cd neutron absorber at a burnup depth of 70 GWd / tU is 85%, indicating that its reactivity value is 85% of the original. The neutron absorption characteristics of the neutron absorbing materials provided by examples 1-4 of the present application at a burnup depth of 70 GWd / tU are ≥95%, indicating that the neutron absorption characteristics remain basically unchanged, i.e. the reactivity value is basically unchanged, thereby prolonging the service life of the control rod neutron absorber.

[0071] Further, in Figure 1 Comparative example 1 and example 3, and comparative example 2 and example 4. It can be seen that the neutron absorbing materials in examples 1 and 2 can further optimize the burnup depth of the neutron absorbing material, reduce the decay loss of the material, and make the neutron absorption characteristics ≥97%. In addition, by comparing examples 1 and 2, examples 3 and 4, it can be found that the neutron absorption characteristics of the neutron absorbing materials in examples 2 and 4 decrease slowly, indicating that examples 2 and 4 can further avoid the material being converted into weak neutron absorbing material after absorbing neutrons, control the neutron absorption characteristics, further improve the neutron absorption characteristics at high burnup depth, effectively maintain the reactivity value, and prolong the service life.

[0072] The technical features of the above-described examples can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above-described examples are described, but as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0073] ​The above-described embodiments only express several implementation manners of the present application, facilitate specific and detailed understanding of the technical solutions of the present application, but cannot be understood as a limitation on the patent protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. It should be understood that, on the basis of the technical solutions provided by the present application, the technical solutions obtained by logical analysis, reasoning or limited experiments by the skilled person in the art all belong to the protection scope of the appended claims of the present application. Therefore, the patent protection scope of the present application should be subject to the content of the appended claims, and the description can be used to explain the content of the claims.

Claims

1. A neutron absorbing material, characterized by, The composition includes a first component, a second component, and a third component. The first component includes Yb₂O₃, the second component includes Ho₂O₃, and the third component includes MoO₃. The neutron absorbing material includes ytterbium and holmium in a mass ratio of (0.7~0.95):

1. The mass ratio of the first component, the second component, and the third component is (0.7~0.95):1:(0.4~4).

2. The neutron absorbing material of claim 1, wherein, The mass percentage of ytterbium in the neutron absorbing material is 7% to 15%.

3. The neutron absorbing material of claim 1, wherein, The mass ratio of the first component, the second component, and the third component is (0.7~0.95):1:(0.4~1).

4. The neutron absorbing material of claim 3, wherein, The mass percentage of ytterbium in the neutron absorbing material is 10% to 15%.

5. The neutron absorbing material of claim 1, wherein, The holmium element in the neutron absorbing material has a mass percentage of 7% to 21%.

6. The neutron absorbing material according to claim 1, characterized in that, Under the condition of a burnup depth of 70 GWd / tU, the neutron absorption characteristics of the neutron absorbing material are ≥90%.

7. A control rod for a nuclear reactor core, characterized in that, It includes a shell and a neutron-absorbing material filled inside the shell, wherein the neutron-absorbing material is the neutron-absorbing material according to any one of claims 1 to 6.

8. The use of the neutron absorbing material according to any one of claims 1 to 6 as a control rod or shielding ceramic material for a high-temperature gas-cooled reactor.

Images