Composition for solidifying radioactive waste liquid, radioactive solidified body and preparation method of radioactive solidified body
By using compositions of alkali-resistant corrosion adsorbents, radionuclide adsorbents and anti-freeze-thaw modifiers, the problem of unstable solidified body in sodium-cold fast reservoir waste liquid treatment is solved, and a radiocured body with high stability and freeze-thaw resistance is achieved, reducing the risk of nuclide leakage and reducing environmental pollution.
Patent Information
- Application Number
- CN202510418563.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-08-05
AI Technical Summary
In the prior art, it is difficult to achieve stable solidification of radioactive waste liquid produced during operation of sodium-cooled fast reactors, resulting in high risk of radionuclide leakage and high possibility of environmental pollution.
The composition of alkali-resistant corrosion adsorbent, radionuclide adsorbent and anti-freeze-thaw modifier is used to form a radiocuring body through mixing, stirring and curing, thereby improving the stability and anti-freeze-thaw ability of the cured body, and reducing the probability of nuclide oozing.
The stable curing of radioactive waste liquid is achieved, the risk of radionuclide leakage is reduced, the structural stability and anti-freeze-thaw properties of radioactive cured bodies are improved, and the possibility of environmental pollution is reduced.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of radionuclide solidification, and in particular to a composition for solidifying radioactive waste liquid, a radioactive solidified body, and a preparation method thereof. Background Art
[0002] Sodium-cooled fast reactors (SFRs) generate a large amount of radioactive waste sodium during operation or after decommissioning. As the operating time of SFRs increases and the number of decommissioned SFRs increases, the treatment of radioactive waste sodium becomes particularly important.
[0003] In related technologies, radioactive waste sodium is solidified and then buried to complete the treatment of radioactive waste sodium, so the stability of the solidified radioactive solid body is particularly important. Summary of the Invention
[0004] In order to solve the above technical problems, the present application provides a composition for solidifying radioactive waste liquid, a radioactive solidified body and a preparation method thereof, which are used to achieve the solidification of radioactive alkaline waste liquid.
[0005] This application is implemented through the following technical solutions.
[0006] In a first aspect, the present application provides a composition for solidifying radioactive waste liquid, which is used to solidify radioactive alkaline waste liquid. Calculated by mass fraction, relative to 144-200 parts of radioactive alkaline waste liquid, the composition for solidifying radioactive waste liquid includes: 397-425 parts of an anti-alkali corrosion adsorbent, 26 parts of a radionuclide adsorbent, and 5 parts of an anti-freeze-thaw modifier.
[0007] In the technical solution of the embodiment of the present application, the composition for solidifying radioactive waste liquid contains an alkaline corrosion resistant adsorbent, a radionuclide adsorbent and an anti-freeze-thaw modifier, wherein the anti-alkaline corrosion adsorbent can be in a stable state in an alkaline environment and adsorb alkaline waste liquid at the same time, the radionuclide adsorbent can adsorb radionuclides, and the anti-freeze-thaw modifier can change and improve the anti-freeze-thaw ability of the radioactive solidified body formed after the radioactive waste liquid solidification composition and the radioactive alkaline waste liquid are mixed, so that the radioactive solidified body has higher stability and anti-freeze-thaw ability, thereby ensuring that the radionuclides inside the radioactive solidified body are stably inside the radioactive solidified body. In this way, after the radioactive solidified body is buried, the probability of radionuclides inside the radioactive solidified body seeping out can also be reduced, or the time of radionuclides inside the radioactive solidified body seeping out can be extended, thereby reducing the probability of environmental pollution.
[0008] In some embodiments of the present application, the freeze-thaw resistance modifier includes at least one of an organic fiber material and an inorganic fiber material.
[0009] In this manner, the freeze-thaw resistance modifier composed of the inorganic fiber material and / or the organic fiber material can improve the freeze-thaw resistance through the fibers.
[0010] In some embodiments of the present application, the inorganic fiber material includes one or more of basalt fiber material, coconut shell fiber material, aramid fiber material, and polyvinyl alcohol material; the inorganic fiber material includes aluminum silicate fiber material.
[0011] With such an arrangement, at least one of the basalt fiber material, coconut shell fiber material, aramid fiber material, polyvinyl alcohol material, and aluminum silicate fiber material can better exert its freeze-thaw resistance.
[0012] In some embodiments of the present application, 26 parts of radionuclide adsorbent include 1 part of alpha nuclide adsorbent and 25 parts of hydrous aluminosilicate mineral.
[0013] With such a configuration, corresponding radionuclide adsorbents can be selected according to the types of radionuclides in the radioactive alkaline waste liquid to specifically adsorb α nuclides, Cs nuclides, and Sr nuclides.
[0014] In some embodiments of the present application, the hydrous aluminosilicate mineral includes zeolite powder.
[0015] With such a configuration, the zeolite powder can better adsorb Cs nuclides and Sr nuclides, thereby increasing the adsorption capacity.
[0016] In some embodiments of the present application, the alkaline corrosion resistant adsorbent includes special cement.
[0017] With such a configuration, the special cement has the characteristics of rapid hardening, good frost resistance and wear resistance. Therefore, the use of the special cement can increase the adsorption rate and improve the frost resistance and wear resistance of the radioactive solidified body.
[0018] In some embodiments of the present application, 397-425 parts of the anti-alkaline corrosion adsorbent include: 372-400 parts of special cement and 25 parts of silica fume.
[0019] With this arrangement, the special cement can adsorb radioactive waste liquid, and the silica powder has good volcanic ash activity and filling properties due to its low density, high specific resistivity, strong cohesion, high adhesion, and difficulty in settling. It can be filled into the tiny pores between the special cement particles and chemically react with the calcium hydroxide produced during the hydration of the special cement to form a gel, for example, calcium silicate hydrate (CaO·SiO2·H2O; CSH) gel can be generated, thereby increasing the density of the radioactive solidified body, thereby further improving the reliability of the finally formed radioactive solidified body. Moreover, during the curing process, no heat is released, which can effectively reduce the hydration heat during the curing process of the special cement.
[0020] A second aspect of the present application provides a radioactive solidified body, which comprises, calculated by mass fraction, 144-200 parts of radioactive alkaline waste liquid and the composition for solidifying radioactive waste liquid according to any of the above embodiments.
[0021] In the technical solution of the embodiment of the present application, the above-mentioned radioactive alkaline waste liquid and the composition for radioactive waste liquid solidification can be mixed and reacted better according to the mass fraction, thereby ensuring the sufficiency of mixing and the stability of the finally formed radioactive solidified body.
[0022] In some embodiments of the present application, the radioactive alkaline waste liquid includes a sodium carbonate solution containing at least one of Cs nuclides, Sr nuclides, and α nuclides.
[0023] In this arrangement, radioactive sodium is processed to form a sodium carbonate solution containing at least one of Cs nuclides, Sr nuclides, and α nuclides, so as to solidify the sodium carbonate solution, thereby facilitating normal solidification.
[0024] A third aspect of the present application provides a preparation method for preparing the radioactive solidified body in any of the above embodiments, the preparation method comprising:
[0025] Mixing and stirring the composition for solidifying radioactive liquid waste of any of the above embodiments with radioactive alkaline waste liquid to obtain a mixed slurry;
[0026] pouring the mixed slurry into a mold, and then demoulding to obtain a pre-radioactive solidified body;
[0027] The pre-radioactive solidified body is cured to obtain a radioactive solidified body.
[0028] In the technical solution of the embodiment of the present application, the composition for solidifying radioactive liquid waste is mixed and stirred with radioactive alkaline waste liquid, and then poured into a mold to obtain a pre-radioactive solidified body, which is then cured to obtain a radioactive solidified body, thereby ensuring the stability of the radioactive solidified body. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:
[0030] Figure 1 Schematic diagram of the process for preparing a radioactive solidified body provided in some embodiments of the present application. DETAILED DESCRIPTION
[0031] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.
[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.
[0033] In the description of the embodiments of this application, the technical terms "first," "second," "third," etc. are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise specifically defined.
[0034] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0035] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.
[0036] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.
[0037] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.
[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.
[0039] Below, this application is described in detail.
[0040] Nanocooled fast reactors (NSRs) are fast breeder reactors using liquid sodium as a coolant. As the preferred reactor type for fourth-generation nuclear power, dozens of these reactors, of varying sizes, have been built worldwide. During operation and after decommissioning, these reactors generate large amounts of radioactive sodium waste. As the operating life of SFRs increases and the number of decommissioned reactors increases, the disposal of these radioactive wastes becomes increasingly important.
[0041] The ultimate goal of radioactive sodium waste treatment is to achieve long-term burial of radioactive waste. To achieve this, the stabilized sodium products must be converted into radioactive solids suitable for final disposal. Specifically, radioactive sodium is typically converted into an alkaline wastewater mixture of radionuclides and sodium salts. This alkaline wastewater is then solidified using a solidification method to form a radioactive solid. This allows the radionuclides to enter the solidified solid, which is then buried, completing the treatment of the radioactive sodium waste.
[0042] Based on this, the present application provides a radioactive solidified body, which includes: radioactive alkaline waste liquid and a composition for solidifying radioactive waste liquid.
[0043] Among them, for sodium-cooled fast reactors, the radioactive alkaline waste liquid refers to radioactive alkaline waste liquid containing sodium, for example, it can be a sodium carbonate solution, and the radionuclides contained in the radioactive alkaline waste liquid are mainly at least one of Cs nuclides, Sr nuclides, and α nuclides.
[0044] In addition, the composition for solidifying radioactive liquid waste must at least have the ability to adsorb alkaline waste liquid and radioactive nuclides and ultimately convert them into a solidified body, so that a stable radioactive solidified body can be formed. The composition for solidifying radioactive liquid waste will be introduced in detail later.
[0045] Through the above arrangement, the radioactive alkaline waste liquid and the radioactive waste liquid solidification composition can be mixed to form a radioactive solidified body, thereby achieving solidification treatment of the radioactive alkaline waste liquid. After solidification treatment, the radioactive solidified body can be buried, thereby achieving treatment of radioactive waste sodium.
[0046] In some embodiments, the radioactive alkaline waste liquid includes a sodium carbonate solution containing at least one of Cs (cesium) nuclides, Sr (strontium) nuclides, and alpha nuclides.
[0047] The Cs nuclide may be present in the sodium carbonate solution in the form of cesium nitrate (CsNO3).
[0048] Furthermore, to facilitate testing the curing ability of the composition for solidifying radioactive liquid waste, a sodium carbonate solution containing radionuclides can be obtained by simulated means, for example, by reacting a sodium hydroxide solution with carbon dioxide to obtain a sodium carbonate solution. For example, the concentration of the sodium carbonate solution can be 30 g / L, and the proportion of cesium nitrate in the sodium carbonate solution can be 1%.
[0049] Through the above arrangement, radioactive sodium is processed to form a sodium carbonate solution containing at least one of Cs nuclides, Sr nuclides, and α nuclides, and then the sodium carbonate solution is solidified using the radioactive waste solidification composition, thereby ensuring normal solidification.
[0050] In order to prevent radioactive solidified bodies from polluting the environment, the stability of the radioactive solidified bodies is particularly important. Therefore, the components of the composition for solidifying radioactive liquid waste are particularly important.
[0051] Based on this demand, the present application also provides a composition for solidifying radioactive waste liquid, which is used to solidify radioactive alkaline waste liquid. Calculated by mass fraction, relative to 144-200 parts of radioactive alkaline waste liquid, the composition for solidifying radioactive waste liquid includes: 397-425 parts of anti-alkali corrosion adsorbent, 26 parts of radionuclide adsorbent and 5 parts of anti-freeze-thaw modifier.
[0052] It can be understood that, calculated by mass fraction, the radioactive waste liquid solidification composition includes: 397-425 parts of the anti-alkaline corrosion adsorbent, 26 parts of the radionuclide adsorbent, and 5 parts of the anti-freeze-thaw modifier, relative to 144-200 parts of the radioactive alkaline waste liquid. It can also be understood that, calculated by mass fraction, the ratio of the radioactive alkaline waste liquid, the anti-alkaline corrosion adsorbent, the radionuclide adsorbent, and the anti-freeze-thaw modifier is: radioactive alkaline waste liquid: anti-alkaline corrosion adsorbent: radionuclide adsorbent: anti-freeze-thaw modifier = (144-200): (397-425): 26: 5. As long as the radioactive alkaline waste liquid, the anti-alkaline corrosion adsorbent, the radionuclide adsorbent, and the anti-freeze-thaw modifier meet the above ratio, they are within the scope of protection of this application.
[0053] Calculated by mass fraction, the number of portions of radioactive alkaline waste liquid can be 144 portions, 160 portions, 180 portions, 190 portions or 200 portions, etc., and can be specifically selected and set according to needs.
[0054] In some examples, the number of parts of radioactive alkaline waste liquid is 144 parts. In this way, when the radioactive alkaline waste liquid is solidified using the radioactive waste liquid solidification composition, a better degree of solidification can be ensured, that is, the stability of the radioactive solidified body finally formed is ensured to be better.
[0055] In other examples, the number of portions of radioactive alkaline waste liquid is 200 portions, so that a certain amount of the radioactive waste liquid solidification composition can be used to solidify more radioactive alkaline waste liquid, while also ensuring the stability of the ultimately formed radioactive solidified body.
[0056] In addition, the amount of the anti-alkaline corrosion adsorbent can be 397 parts, 400 parts, 410 parts, 415 parts or 425 parts by mass, etc., and can be selected and set according to needs.
[0057] In some examples, relative to 144 parts of radioactive alkaline waste liquid, the composition for solidifying radioactive waste liquid may include: 397 parts of anti-alkaline corrosion adsorbent, 26 parts of radionuclide adsorbent and 5 parts of anti-freeze-thaw modifier. This not only ensures the solidification performance of the composition for solidifying radioactive waste liquid, but also saves the raw materials of the anti-alkaline corrosion adsorbent to control the material cost.
[0058] In other examples, relative to 144 parts of radioactive alkaline waste liquid, the composition for radioactive waste liquid solidification may include: 425 parts of anti-alkali corrosion adsorbent, 26 parts of radionuclide adsorbent and 5 parts of anti-freeze-thaw modifier. This not only can the solidification performance of the composition for radioactive waste liquid solidification be guaranteed to the greatest extent, but also can control the raw material cost of the anti-alkali corrosion adsorbent.
[0059] It is understood that the anti-alkaline corrosion adsorbent refers to a substance that can be applied to an alkaline environment, can adsorb alkaline waste liquid, and eventually solidify. In addition, a radionuclide adsorbent refers to a substance that can adsorb radionuclides. The antifreeze-thaw modifier refers to a substance that can improve the antifreeze-thaw ability of a radioactive solidified body. In other words, the radioactive solidified body formed after adding the antifreeze-thaw modifier has a high compressive strength after being frozen. For example, it can still withstand a pressure of more than 7 MPa, thereby ensuring the stability of the radioactive solidified body. In addition, the antifreeze-thaw modifier also needs to have the characteristics of alkali resistance, so as to exert the performance of stable antifreeze-thaw modification.
[0060] Through the above arrangement, the composition for solidifying radioactive waste liquid includes an alkaline corrosion resistant adsorbent, a radionuclide adsorbent, and a freeze-thaw resistance modifier. Among them, the alkaline corrosion resistant adsorbent can remain in a stable state in an alkaline environment, while adsorbing alkaline waste liquid and solidifying. The radionuclide adsorbent can adsorb radionuclides. The freeze-thaw resistance modifier can change and improve the freeze-thaw resistance of a radioactive solidified body formed after mixing the radioactive waste liquid solidification composition and radioactive alkaline waste liquid, so that the radioactive solidified body has higher stability and freeze-thaw resistance, thereby ensuring that the radionuclides in the radioactive solidified body are stably located in the radioactive solidified body. In this way, after the radioactive solidified body is buried, the probability of radionuclides in the radioactive solidified body seeping out can be reduced, or the time for radionuclides in the radioactive solidified body to seep out can be extended, thereby reducing the probability of environmental pollution.
[0061] In addition, the radioactive alkaline waste liquid and the composition for solidifying radioactive waste liquid in the above amounts can be mixed and reacted better, thereby ensuring sufficient mixing and ensuring the stability of the radioactive solidified body finally formed.
[0062] In some embodiments, the freeze-thaw resistance modifier includes at least one of an organic fiber material and an inorganic fiber material.
[0063] In other words, the material contained in the antifreeze modifier is a fiber material. After the radioactive solidified body is formed, the fiber material will exist inside the radioactive solidified body. The fiber material can prevent the expansion of microcracks in the radioactive solidified body, reduce the internal stress concentration caused by the freeze-thaw cycle, and delay frost heave damage. At the same time, the limiting material can also be filled into the pores inside the radioactive solidified body to inhibit the infiltration of moisture from the outside of the radioactive solidified body to ensure the stability of the radioactive solidified body.
[0064] In addition, it is understood that both the organic fiber material and the inorganic fiber material need to have the characteristic of alkali resistance, so as to exert the stable anti-freeze-thaw modification performance.
[0065] Through the above-mentioned setting, the anti-freeze-thaw modifier composed of inorganic fiber material and / or organic fiber material can improve the anti-freeze-thaw ability of the radioactive solidified body finally formed by solidification through the fiber, thereby ensuring that the radioactive solidified body can still maintain structural stability in a freezing environment, thereby avoiding the radioactive nuclides inside the radioactive solidified body from polluting the environment after being buried.
[0066] In some embodiments, the inorganic fiber material includes one or more of basalt fiber material, coconut shell fiber material, aramid fiber material, and polyvinyl alcohol material; the inorganic fiber material includes aluminum silicate fiber material.
[0067] It can be understood that basalt fiber materials, coconut shell fiber materials, aramid fiber materials, polyvinyl alcohol materials and aluminum silicate fiber materials all have the characteristics of high strength and temperature resistance, which can ensure the structural strength of the radioactive solidified body finally formed, and they also have good acid and alkali corrosion resistance, so they can be suitable for the alkaline application environment in this application.
[0068] Through the above-mentioned arrangement, at least one of the basalt fiber material, coconut shell fiber material, aramid fiber material, polyvinyl alcohol material, and aluminum silicate fiber material has the characteristics of high strength, temperature resistance, and alkaline corrosion resistance. Therefore, it can not only be used in the alkaline application environment of the present application, but also can improve the structural strength and temperature resistance of the finally formed radioactive solidified body, thereby improving the freeze-thaw resistance of the radioactive solidified body, and ensuring that the radioactive solidified body can still maintain sufficient pressure resistance in a freezing environment.
[0069] In order to more clearly understand the freeze-thaw resistance of the above-mentioned fiber materials, relevant experimental tests are carried out below. See Table 1 for details.
[0070] Table 1
[0071]
[0072]
[0073] The compressive strength of the radioactive solidified body before the freeze-thaw test refers to the pressure it can withstand before the freeze-thaw test. The compressive strength of the radioactive solidified body after the freeze-thaw test refers to the pressure it can withstand after the freeze-thaw test. Under general standards, the degree of reduction in the compressive strength of the radioactive solidified body after the freeze-thaw test should not be less than 25% of the compressive strength of the radioactive solidified body before the freeze-thaw test.
[0074] The test of the compressive strength of the radioactive solidified body before and after freezing and thawing belongs to the compression test, while the weight loss of the radioactive solidified body before and after the compression test is a test of the amount of liquid seepage inside the radioactive solidified body.
[0075] The above experiments demonstrate that polyvinyl alcohol fibers exhibit a certain degree of fiber adsorption, and their chemical stability is significantly improved compared to other components. This indicates that polyvinyl alcohol fibers not only enhance the mechanical properties of radioactive solidified materials but also improve their stability. Polyvinyl alcohol fibers also possess a certain degree of sodium ion adsorption capacity. The sodium ion dissolution rate in radioactive solidified materials containing a certain amount of polyvinyl alcohol fibers is reduced, thus maintaining a high level of stability even after freezing.
[0076] In other embodiments, the freeze-thaw resistance modifier may also include materials such as micro-expansive cement-based composite materials or titanium alloy reinforcements.
[0077] In some embodiments, the 26 parts radionuclide adsorbent includes 1 part alpha nuclide adsorbent and 25 parts hydrous aluminosilicate mineral.
[0078] It can be understood that for sodium-cooled fast reactors, the nuclides they contain are mainly Cs (cesium) nuclides, Sr (strontium) nuclides, and α nuclides. Among them, hydrous aluminosilicate minerals can be used to adsorb Cs (cesium) nuclides and Sr (strontium) nuclides, while α nuclide adsorbents can be used to adsorb α nuclides.
[0079] For example, the α-nuclide adsorbent may include: porous silica-supported anion exchange resin or anion exchange resin, etc.
[0080] For example, the hydrous aluminosilicate mineral may include zeolite powder, mica, halloysite, imogolite, allophane, montmorillonite or garnet.
[0081] Since hydrous aluminosilicate minerals contain Si (silicon) ions and Al (aluminum) ions, the Al / Si structure can further produce hydrated silica gel during the hydration process. The hydrated silica gel can improve the adhesion between ions within the radioactive solidified body, thereby exerting a certain stabilizing effect, so that the radioactive solidified body has higher structural strength and higher stability.
[0082] Through the above arrangement, the corresponding radionuclide adsorbent, namely, the α-nuclide adsorbent and the hydrous aluminosilicate mineral, can be selected according to the type of radionuclide in the radioactive alkaline waste liquid. This allows for the targeted adsorption of α-nuclides, Cs-nuclides, and Sr-nuclides, thereby ensuring that the α-nuclides, Cs-nuclides, and Sr-nuclides are stably retained within the radioactive solidified body, preventing their leakage and thus ensuring the structural stability of the radioactive solidified body. Furthermore, the hydrous aluminosilicate mineral can also enhance the stability of the radioactive solidified body.
[0083] In some embodiments, the hydrous aluminosilicate mineral comprises zeolite powder.
[0084] Zeolite powder additives can improve the chemical stability of Si to a certain extent, mainly because the Al / Si structure inside the zeolite powder can further produce hydrated silica gel during the hydration process. At the same time, the zeolite powder itself can continuously transform into a new Al / Si mineral phase, thereby playing a certain stabilizing role.
[0085] Through the above-mentioned setting, the zeolite powder can better adsorb Cs nuclides and Sr nuclides, improve the adsorption capacity, and further ensure the structural stability of the radioactive solidified body, thereby preventing the radioactive solidified body from polluting the surrounding environment.
[0086] In some embodiments, the alkaline corrosion-resistant adsorbent comprises specialty cement. This means that the resulting radioactive solidified body is a cement radioactive solidified body. Specialty cement has the characteristics of rapid hardening, excellent frost resistance, and wear resistance. Therefore, the use of specialty cement can increase the adsorption rate and improve the frost resistance and wear resistance of the radioactive solidified body.
[0087] In some embodiments, 397-425 parts of the anti-alkaline corrosion adsorbent include: 372-400 parts of special cement and 25 parts of silica fume.
[0088] The proportion of special cement is 372 parts, 380 parts, 385 parts, 390 parts or 400 parts, etc. The proportion can be selected according to actual needs.
[0089] Through the above-mentioned arrangement, the special cement can adsorb and condense radioactive waste liquid. Silica powder has good volcanic ash activity and filling properties due to its low density, high specific resistivity, strong cohesiveness, high adhesion, and difficulty in settling. It can be filled into the tiny pores between the special cement particles and chemically react with the calcium hydroxide produced during the hydration of the special cement to form a gel, thereby increasing the density of the radioactive solidified body and further improving the reliability of the ultimately formed radioactive solidified body. Furthermore, during the curing process, no heat is released, which can effectively reduce the hydration heat during the curing process of the special cement.
[0090] In terms of the contact of the radioactive solidified body, the present application also provides a preparation method for preparing the radioactive solidified body in any of the above embodiments, such as Figure 1 As shown, the preparation method includes S100-S300:
[0091] S100: mixing and stirring the radioactive waste liquid solidification composition and the radioactive alkaline waste liquid to obtain a mixed slurry.
[0092] It can be understood that, calculated by mass fraction, the radioactive waste liquid solidification composition is obtained by mixing 144-200 parts of radioactive alkaline waste liquid, 397-425 parts of anti-alkali corrosion adsorbent, 26 parts of radionuclide adsorbent and 5 parts of anti-freeze-thaw modifier.
[0093] S200: pouring the mixed slurry into a mold, and then demoulding to obtain a pre-radioactive solidified body.
[0094] The space inside the mold can be in a regular shape such as a cube or a sphere, and the pre-radioactive solidified body thus formed can also be in a regular shape such as a cube or a sphere. Of course, the space inside the mold can also be in an irregular shape.
[0095] S300: Curing the pre-radioactive solidified body to obtain a radioactive solidified body.
[0096] It is understandable that when curing the pre-radioactive solidified body, it is best to perform curing under a standard environment. For example, it needs to be left to stand for a certain period of time under specific environmental characteristics such as temperature and humidity to ensure that the formed radioactive solidified body is in a stable state to meet burial conditions.
[0097] Through the above arrangement, the radioactive liquid waste solidification composition is mixed and stirred with radioactive alkaline waste liquid, and then poured into a mold to obtain a pre-radioactive solidified body. The pre-radioactive solidified body is then cured to obtain a radioactive solidified body. This ensures the stability of the radioactive solidified body, so that the radioactive solidified body meets the subsequent burial conditions.
[0098] In some embodiments, after S300, the preparation method further includes S400: testing the radioactive solidified body to determine whether the radioactive solidified body is qualified. This ensures that the radioactive solidified body can be stored stably and long-term after burial, thereby preventing radionuclides within the radioactive solidified body from contaminating the surrounding environment. The solidified body formed by mixing the radioactive liquid waste solidification composition and radioactive alkaline waste liquid in the specified ratio of the present application can meet the test requirements.
[0099] The testing of radioactive solidified materials is based on the performance indicators listed in GB14569.1-2011, including the following four test indicators.
[0100] 1. At room temperature and in a sealed condition, there should be no free liquid secreted from the radioactive solidified body after curing.
[0101] 2. After curing and complete hardening at room temperature and in a sealed environment, the radioactive solidified body shall be a dense, uniform, and stable block and shall meet the following requirements:
[0102] (1) The compressive strength of the radioactive solidified body should not be less than 7 MPa;
[0103] (2) When a radioactive solidified body sample or a radioactive solidified body with a packaging container is dropped vertically from a height of 9 m onto a concrete floor, there should be no obvious breakage.
[0104] 3. Radioactive solidification has good water resistance:
[0105] (1) Resistance to leaching
[0106] The radioactive solidified body shall be leached in deionized water at 25°C and shall meet the limit requirements of leaching rate and cumulative leaching fraction.
[0107] The leaching rate of nuclides contained in the radioactive solidified body on the 42nd day should be lower than the following limits:
[0108] 1. 60 Co: 2×10 -3 cm / d;
[0109] 2. 137 Cs: 4×10 -3 cm / d;
[0110] 3. 90 Sr: 1×10 -3 cm / d;
[0111] 4. 239 Pu: 1×10 -5 cm / d;
[0112] 5. Other β and γ radionuclides (excluding 3 H): 4×10 -3 cm / d;
[0113] 6. Other alpha nuclides: 1×10 -5 cm / d.
[0114] The cumulative leaching fraction of nuclides contained in the radioactive solidified body within 42 days shall be lower than the following limits: 137 Cs: 0.26cm;
[0115] 2. Other radionuclides (excluding 3 H): 0.17cm.
[0116] (2) Anti-immersion:
[0117] After the anti-immersion test of the radioactive solidified body sample, there should be no obvious cracks or fissures on its appearance, and the loss of compressive strength should not exceed 25%.
[0118] 4. Radioactive solidification has good freeze-thaw resistance:
[0119] After the freeze-thaw resistance test, the radioactive solidified body should not have obvious cracks or fissures on its appearance, and the loss of compressive strength should not exceed 25%.
[0120] The performance requirements of the radioactive solidified body before complete solidification must meet the following requirements:
[0121] 1. The initial setting time shall not exceed 24 hours.
[0122] 2. Final setting time shall not exceed 72 hours.
[0123] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A composition for solidifying radioactive waste liquid, used for solidifying radioactive alkaline waste liquid, characterized in that: Calculated by mass fraction, relative to 144-200 parts of the radioactive alkaline waste liquid, the radioactive waste liquid solidification composition includes: 397-425 parts of anti-alkali corrosion adsorbent, 26 parts of radionuclide adsorbent and 5 parts of anti-freeze-thaw modifier.
2. The composition for solidifying radioactive liquid waste according to claim 1, characterized in that The antifreeze-thaw modifier includes at least one of an organic fiber material and an inorganic fiber material.
3. The composition for solidifying radioactive liquid waste according to claim 2, characterized in that The inorganic fiber material includes one or more of basalt fiber material, coconut shell fiber material, aramid fiber material, and polyvinyl alcohol material; The inorganic fiber material includes: aluminum silicate fiber material.
4. The composition for solidifying radioactive liquid waste according to claim 1, wherein The 26 parts of radionuclide adsorbents include 1 part of α-nuclide adsorbent and 25 parts of hydrous aluminosilicate minerals.
5. The composition for solidifying radioactive liquid waste according to claim 4, characterized in that The hydrous aluminosilicate mineral includes zeolite powder.
6. The composition for solidifying radioactive liquid waste according to any one of claims 1 to 5, characterized in that The alkaline corrosion resistant adsorbent comprises special cement.
7. The composition for solidifying radioactive liquid waste according to any one of claims 1 to 5, characterized in that The 397-425 parts of anti-alkaline corrosion adsorbent include: 372-400 parts of special cement and 25 parts of silicon powder.
8. A radioactive solidified body, characterized in that: Calculated by mass fraction, the radioactive solidified body includes: 144-200 parts of radioactive alkaline waste liquid; The composition for solidifying radioactive liquid waste according to any one of claims 1 to 7.
9. The radioactive solidified body according to claim 8, characterized in that The radioactive alkaline waste liquid includes a sodium carbonate solution containing at least one of Cs nuclides, Sr nuclides, and α nuclides.
10. A method for preparing the radioactive solidified body according to claim 8 or 9, characterized in that: The preparation method comprises: Mixing and stirring the composition for solidifying radioactive liquid waste according to any one of claims 1 to 7 with radioactive alkaline waste liquid to obtain a mixed slurry; pouring the mixed slurry into a mold, and then demoulding to obtain a pre-radioactive solidified body; The pre-radioactive solidified body is cured to obtain the radioactive solidified body.