System for treating radioactive waste sodium and method for treating radioactive waste sodium

Abstract

The embodiment of the invention relates to the technical field of radioactive waste sodium treatment, in particular to a system and method for treating radioactive waste sodium, and the system comprises a sodium storage device which is used for storing radioactive waste sodium to be treated and conveying liquid sodium into a sodium treatment device at a preset speed; the sodium treatment device is used for receiving liquid sodium and carrying out oxidation reduction treatment on metal sodium in the liquid sodium to obtain a sodium oxidation product; the transfer device is used for collecting a sodium oxidation product obtained after treatment of the sodium treatment device and transferring the sodium oxidation product to the glass curing device; and the glass curing device is used for carrying out glass curing on the sodium oxidation product in an inert atmosphere to obtain a glass cured product. According to the system, the radioactive waste sodium containing insoluble impurities can be safely converted through the oxidation-reduction reaction, the treatment process is mild, the treatment efficiency is high, and the purpose of treating a large amount of radioactive waste sodium at a time is achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of radioactive waste sodium treatment, and specifically to a system for treating radioactive waste sodium and a method for treating radioactive waste sodium. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] During operation, sodium-cooled fast reactors (SFRs) generate a small amount of waste residue containing radioactive sodium due to equipment maintenance and replacement. Because radioactive sodium waste has the characteristics of both a hazardous chemical and a radioactive substance, it requires proper disposal to reduce safety risks.

[0004] However, the current methods and equipment for treating radioactive waste sodium still have many shortcomings. Summary of the Invention

[0005] A brief overview of the present application is provided below to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify key or important portions of the present application, nor is it intended to limit the scope of the present application. Its purpose is simply to present certain concepts in a simplified form as a prelude to the more detailed description that will be discussed later.

[0006] In a first aspect, an embodiment of the present application provides a system for treating radioactive waste sodium, comprising: a sodium storage device, a sodium treatment device, a transfer device, and a vitrification device, wherein the sodium storage device is used to store radioactive waste sodium to be treated, and is configured to transport liquid sodium to the sodium treatment device at a predetermined rate; the sodium treatment device is used to receive liquid sodium and perform oxidation-reduction treatment on metallic sodium in the liquid sodium to obtain sodium oxidation products; the transfer device is used to collect the sodium oxidation products obtained after treatment by the sodium treatment device and transfer the sodium oxidation products to the vitrification device; and the vitrification device is used to vitrify the sodium oxidation products under an inert atmosphere to obtain a vitrified material.

[0007] In the embodiments of the present application, a sodium treatment device performs redox treatment on liquid sodium transported from a sodium storage device, thereby achieving safe conversion of radioactive waste sodium containing insoluble impurities. Furthermore, the treatment process is relatively mild and highly efficient. Furthermore, since the sodium storage device transports liquid sodium to the sodium treatment device at a predetermined rate, this facilitates ensuring smooth redox reactions of the sodium, thereby enabling the one-time treatment of a relatively large amount of radioactive waste sodium. The sodium oxidation product obtained after treatment by the sodium treatment device is then transferred to a vitrification device by a transfer device, thereby achieving vitrification of the radioactive waste sodium and ensuring effective treatment of the radioactive waste sodium.

[0008] In a second aspect, an embodiment of the present application further provides a method for treating radioactive waste sodium, which is applicable to the system of an embodiment of the present application, and includes the following steps: S1, transporting liquid sodium to a sodium treatment device in the system at a predetermined speed; S2, performing redox treatment on the metallic sodium in the liquid sodium to obtain a sodium oxidation product; S3, collecting the sodium oxidation product obtained after treatment by the sodium treatment device, and transferring the sodium oxidation product to a glass solidification device in the system; S4, performing glass solidification on the sodium oxidation product under an inert atmosphere to obtain a glass solidified material.

[0009] These and other advantages of the present application will become more apparent through the following detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] To further illustrate the above and other advantages and features of the present application, the following detailed description of specific embodiments of the present application is provided in conjunction with the accompanying drawings. The accompanying drawings, together with the detailed description below, are incorporated into and form a part of this specification. Elements with the same function and structure are denoted by the same reference numerals. It should be understood that these drawings depict only typical examples of the present application and should not be construed as limiting the scope of the present application.

[0011] Figure 1 is a schematic block diagram of a system for treating radioactive waste sodium according to an embodiment of the present application;

[0012] Figure 2 is a schematic structural diagram of a sodium processing device according to an embodiment of the present application;

[0013] Figure 3 yes Figure 2 A top view of the sodium processing unit is shown;

[0014] Figure 4 is a schematic flow chart of a method for treating radioactive waste sodium according to an embodiment of the present application.

[0015] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding.

[0016] Description of reference numerals:

[0017] 10. Sodium storage device;

[0018] 11. Sodium processing equipment;

[0019] 111, first container body; 1110, first chamber; 1111, first shell; 11111, opening; 1112, second shell; 1113, sealing member; 11131, gas flow port; 11132, exhaust gas outlet; 11133, pressure regulating port; 1114, cover; 11141, gas inlet; 11142, first heating interface; 112, second container body; 1120, second chamber; 1121, thermal liquid inlet; 1122, thermal liquid outlet; 1123, second heating interface; 113, barrier; 114, heating assembly; 1141, first heating element; 1142, second heating element; 1151, first sealing connector; 1152, second sealing connector;

[0020] 12. Transfer device;

[0021] 13. Glass curing device;

[0022] 14. Exhaust gas treatment device;

[0023] 15. Inert gas buffer container;

[0024] 16. Pure water device. DETAILED DESCRIPTION

[0025] Exemplary embodiments of the present application will be described below with reference to the accompanying drawings. For the sake of clarity and conciseness, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary depending on the implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is a routine task for those skilled in the art who benefit from the content of this application.

[0026] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, the accompanying drawings only show the device structure and / or processing steps that are closely related to the solution according to the present application, while other details that are not closely related to the present application are omitted.

[0027] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application should have the common meanings understood by persons having ordinary skills in the field to which this application belongs.

[0028] In the description of the embodiments of the present application, “multiple” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] Currently, the common method for treating radioactive sodium waste is to convert it into oxides, alkalis, or salts to reduce its reactivity, and then solidify the converted material in an inert matrix. However, the equipment used in this treatment method is typically only capable of processing small batches of highly reactive sodium at a time, resulting in low processing efficiency. Furthermore, the process generates flammable and explosive gases and releases large amounts of heat, making it difficult to ensure safety during the process.

[0030] In response to the above technical problems, an embodiment of the present application provides a system for treating radioactive waste sodium. Figure 1 is a schematic block diagram of a system for treating radioactive waste sodium (hereinafter referred to as a treatment system) according to an embodiment of the present application, such as Figure 1 As shown, the processing system may include a sodium storage device 10 , a sodium processing device 11 , a transfer device 12 , and a vitrification device 13 .

[0031] The sodium storage device 10 is used to store radioactive waste sodium to be processed, and is configured to transport liquid sodium to the sodium processing device 11 at a predetermined speed.

[0032] The sodium processing device 11 is used to receive liquid sodium and perform redox treatment on the metallic sodium in the liquid sodium to obtain sodium oxidation products.

[0033] The transfer device 12 is used to collect the sodium oxidation products obtained after being processed by the sodium processing device 11 and transfer the sodium oxidation products to the glass solidification device 13.

[0034] The glass solidification device 13 is used to perform glass solidification on the sodium oxidation product under an inert atmosphere to obtain a glass solidified material.

[0035] In the embodiment of the present application, the sodium treatment device 11 performs redox treatment on the liquid sodium transported by the sodium storage device 10, thereby achieving safe conversion of radioactive waste sodium containing insoluble impurities. Furthermore, the treatment process is relatively mild and highly efficient. Furthermore, since the sodium storage device 10 transports liquid sodium to the sodium treatment device 11 at a predetermined rate, this facilitates ensuring smooth redox reactions of the sodium, thereby achieving the goal of treating a relatively large amount of radioactive waste sodium at one time. The sodium oxidation product obtained after treatment by the sodium treatment device 11 is then transferred to the vitrification device 13 by the transfer device 12, thereby achieving vitrification of the radioactive waste sodium and ensuring effective treatment of the radioactive waste sodium.

[0036] In some embodiments, the processing system includes a sodium delivery pipeline. The sodium storage device 10 is configured as a pressure device and is connected to the sodium processing device 11 through the sodium delivery pipeline to deliver liquid sodium to the sodium processing device 11.

[0037] In some embodiments, the sodium storage device 10 includes a sodium storage container and a sodium storage heater. The sodium storage container is used to store radioactive waste sodium to be processed. The sodium storage heater can be disposed outside the sodium storage container to heat the radioactive waste sodium stored therein to form liquid sodium.

[0038] In some embodiments, the sodium storage device 10 further includes a heat-insulating member disposed outside the sodium storage container for heat-insulating the sodium storage container. For example, the heat-insulating member may be heat-insulating cotton.

[0039] In some embodiments, the sodium storage device 10 further includes a temperature measuring element and a cooling element. The temperature measuring element and the cooling element are disposed on the top of the sodium storage container. The temperature measuring element is used to detect the temperature in the sodium storage container, and the cooling element is used to cool and collect the sodium vapor evaporated from the sodium storage container.

[0040] In some embodiments, the temperature measuring element is a thermocouple, and the cooling element is a sodium vapor trap.

[0041] In some embodiments, the sodium storage device 10 further includes a pressure vessel. The pressure vessel is in fluid communication with the sodium storage container and is configured to provide a slightly positive pressure inert gas atmosphere for the sodium storage container. The pressure vessel is configured to pressurize the liquid sodium in the sodium storage container into the sodium processing device 11 by gas pressure during the redox reaction.

[0042] In some embodiments, the sodium processing device 11 may be a high-temperature reactor.

[0043] In some embodiments, the transfer device 12 may include a moving member and a moving container. The moving container is disposed on the moving member and is used to collect the sodium oxidation product obtained after treatment by the sodium treatment device 11. The moving member is used to move the moving container to the glass solidification device 13.

[0044] In some embodiments, the movable container may be a crucible into which a pre-prepared glass curing agent for glass curing is added.

[0045] In some embodiments, the glass solidification device 13 may be a muffle furnace.

[0046] In some embodiments, the glass curing device 13 includes a glass curing container and a glass curing heating element.

[0047] The vitrification vessel forms a reaction chamber for the vitrification reaction of the sodium oxide product with the vitrification agent. The vitrification vessel has a bottom-opening door. When the bottom is open, a conveyor can first transfer the crucible to the bottom of the vitrification device 13 and then lift it up to transfer the crucible to the reaction chamber within the vitrification vessel.

[0048] The glass curing heating element is arranged in the glass curing container and is used to heat the reaction chamber inside. The glass curing heating element can be a heating electrode.

[0049] In some embodiments, the glass solidification device 13 further includes a temperature measuring element and a stirring element. The temperature measuring element is configured to continuously detect the temperature in the reaction chamber. The stirring element is disposed in the reaction chamber of the glass solidification container to stir the molten glass.

[0050] In some embodiments, the inert atmosphere is an argon atmosphere.

[0051] In some embodiments, Figure 2 is a structural diagram of the sodium processing device 11 according to an embodiment of the present application, as shown in FIG. Figure 2 As shown, the sodium processing device 11 may include a first container body 111 , a second container body 112 , a plurality of barriers 113 and a heating assembly 114 .

[0052] The first container body 111 is formed with a first chamber 1110, which is used to accommodate liquid sodium and an oxidant for performing an oxidation-reduction reaction with the liquid sodium and provide a reaction space for the oxidation-reduction reaction; the first container body 111 is connected to the sodium storage device 10 to receive the liquid sodium transported from the sodium processing device 11; the second container body 112 is arranged outside the first container body 111 to form a second chamber 1120 with the outer wall of the first container body 111, and the top and bottom of the first container body 111 extend outwardly along the second container body 112 respectively, for heating the first chamber 1110 in a heated state and, at the same time, for heating the first chamber 1110 in an oxidation-reduction state. In the original reaction state, the reaction heat of the first chamber 1110 is removed; multiple barriers 113, the multiple barriers 113 are respectively arranged in the first chamber 1110 of the first container body 111, and one barrier 113 is arranged near the top of the first chamber 1110, and the other barrier 113 is arranged near the bottom of the first chamber 1110, and the barrier 113 is used to block the reactants in the redox reaction; a heating component 114, the heating component 114 is partially arranged outside the first container body 111, and partially arranged outside the second container body 112, and is used to heat the interior of the first chamber 1110 of the first container body 111 and the interior of the second chamber 1120 of the second container body 112.

[0053] In an embodiment of the present application, the sodium processing device 11 is configured to include a first container body 111, a second container body 112, a plurality of barriers 113, and a heating assembly 114. The heating assembly 114 can be used to heat the interior of the first chamber 1110 of the first container body 111 and the interior of the second chamber 1120 of the second container body 112, respectively, to ensure that there is sufficient reaction space when the redox reaction is performed, thereby ensuring that the redox reaction proceeds smoothly. The barriers 113 are used to prevent reactants from leaving the reaction space, thereby further improving the reliability of the redox reaction.

[0054] In some embodiments, the first container body 111 may be a barrel-shaped container, and the second container body 112 may be a table-shaped container, so as to save space occupied by the structure while ensuring that the redox reaction can fully react.

[0055] In some embodiments, before treating the radioactive waste sodium, an oxidant may be added into the first container body 111 of the sodium treatment device 11 to perform an oxidation-reduction reaction with the liquid sodium, thereby obtaining a sodium oxidation product.

[0056] In some embodiments, the oxidizing agent may be iron oxide powder.

[0057] In some embodiments, the barrier 113 disposed near the bottom of the first chamber 1110 can also be used to collect sodium oxidation products.

[0058] In some embodiments, the interior of the first chamber 1110 of the first container body 111 and the interior of the second chamber 1120 of the second container body 112 can be heated using the heating assembly 114. After heating to a predetermined reaction temperature, the sodium storage device 10 begins to deliver liquid sodium at a predetermined rate into the first container body 111. For example, the heating assembly 114 can heat the iron oxide powder in the first chamber 1110.

[0059] In some embodiments, the predetermined reaction temperature is in the range of 380-400° C. For example, the predetermined reaction temperature is 380° C.

[0060] In some embodiments, the first container body 111 includes a first shell 1111, a second shell 1112, a seal 1113, and a cover 1114; the first end of the first shell 1111 is connected to the seal 1113, and the second end of the first shell 1111 forms a funnel-shaped opening 11111; the first shell 1111 forms a sodium transport portion, and the sodium storage device 10 is connected to the first shell 1111 via the sodium transport portion; the first end of the second shell 1112 is connected to the second end of the first shell 1111, and the second end of the second shell 1112 is connected to the cover 1114. The cover 1114 is used to open or close the first chamber 1110, wherein the cover 1114 is configured to: when opened, remove sodium oxidation products from the first chamber 1110, and when closed, seal the first chamber 1110.

[0061] In the embodiment of the present application, by configuring the first container body 111 to include a first shell 1111, a second shell 1112, a seal 1113, and a cover 1114, it is possible to save structural space while further ensuring that the redox reaction has sufficient reaction space. The cover 1114 is then used to open or close the first chamber 1110 to facilitate the transfer of the oxidation product, and the operation is relatively simple.

[0062] In some embodiments, the liquid sodium stored in the sodium storage device 10 may be transported to the reaction space of the first container body 111 via the sodium transport pipeline and the sodium transport portion of the first container body 111 .

[0063] In some embodiments, the sodium delivery unit may be a dropper, with one end of the sodium delivery pipeline connected to the dropper and the other end connected to the sodium storage container, for dripping liquid sodium into the reaction space of the first container body 111 under pressure. By configuring the sodium delivery unit as a dropper structure, it is possible to easily control the dripping rate of the liquid sodium when delivering it into the reaction space of the first container body 111, thereby ensuring that the redox reaction can proceed sufficiently.

[0064] In some embodiments, the sodium processing device 11 further includes a first sealing connector 1151 and a second sealing connector 1152. The first sealing connector 1151 is used to seal the first end of the first housing 1111 with the sealing member 1113. The second sealing member 1113 is used to seal the second end of the second housing 1112 with the cover 1114.

[0065] In some embodiments, the first sealing connector 1151 and the second sealing connector 1152 are clamps.

[0066] In some embodiments, a barrier 113 is disposed at a position where the first end of the first shell 1111 is connected to the sealing member 1113, and another barrier 113 is disposed at a position where the second end of the second shell 1112 is connected to the cover 1114 to prevent the oxidant from leaving the reaction space used for redox reaction.

[0067] In some embodiments, an air inlet 11141 is formed on the cover 1114 , and the air inlet 11141 is used to transport inert gas into the first chamber 1110 to ensure that the first chamber 1110 is filled with inert gas, thereby ensuring the smooth progress of the redox reaction.

[0068] like Figure 2 As shown, the air inlet 11141 can be provided at the lower portion of the cover 1114 to fluidize the oxidant powder in the first chamber 1110 .

[0069] In some embodiments, the seal 1113 forms a gas flow port 11131, which is used to evacuate the first chamber 1110 during the process of transporting inert gas into the first chamber 1110, so as to replace the gas in the first chamber 1110 and avoid air residue.

[0070] In some embodiments, the gas flow port 11131 may be a vacuum port. The processing system further includes a vacuum pump connected to the vacuum port for evacuating the first chamber 1110 and continuously supplying an inert gas into the first chamber 1110 through the gas inlet 11141 on the cover 1114 during the evacuation, thereby displacing the gas in the first chamber 1110.

[0071] In some embodiments, reference Figure 1 The processing system of the embodiment of the present application further includes an inert gas buffer container 15, which is fluidically connected to the sodium processing device 11 and the glass solidification device 13, respectively, for transporting inert gas to the sodium processing device 11 and the glass solidification device 13, respectively.

[0072] In the embodiment of the present application, the inert gas buffer container 15 is fluidically connected to the sodium treatment device 11 and the glass solidification device 13, respectively, which helps to ensure that the operations involved in the redox process and the glass solidification process can be carried out in an inert atmosphere, thereby avoiding the reaction of metallic sodium with air.

[0073] In some embodiments, the gas inlet 11141 on the cover 1114 is in fluid communication with the inert gas buffer container 15 to deliver the inert gas into the first chamber 1110 .

[0074] In some embodiments, the seal 1113 further forms a pressure regulating port 11133 for regulating the pressure in the first chamber 1110 so as to maintain the pressure in the first chamber 1110 within a predetermined range.

[0075] In some embodiments, the sodium processing device 11 further includes a safety valve connected to the pressure regulating port 11133 for regulating the pressure in the first chamber 1110 .

[0076] In some embodiments, the second container body 112 is formed with a heat-conducting liquid inlet 1121 and a heat-conducting liquid outlet 1122, and the heat-conducting liquid inlet 1121 and the heat-conducting liquid outlet 1122 are respectively arranged on opposite sides of the second container body 112, and the heat-conducting liquid outlet 1122 is relatively arranged above the heat-conducting liquid inlet 1121, so that when the heat-conducting liquid flows from the heat-conducting liquid inlet 1121 to the heat-conducting liquid outlet 1122, convection is formed with the gas in the second chamber 1120, and at the same time, gas residue is prevented in the second chamber 1120.

[0077] In the embodiment of the present application, the heat-conducting liquid inlet 1121 and the heat-conducting liquid outlet 1122 are respectively arranged on opposite sides of the second container body 112, and the heat-conducting liquid outlet 1122 is relatively arranged above the heat-conducting liquid inlet 1121. This is beneficial for forming hot air convection when the heat-conducting liquid enters and flows out of the second chamber 1120, thereby ensuring the heating effect and preventing gas residue in the second chamber 1120, which is beneficial for accelerating the reaction process of the redox reaction.

[0078] In some embodiments, the sodium processing device 11 further includes a centrifugal pump, which is disposed in the heat transfer liquid loop and is used to force the heat transfer liquid to circulate so as to form convection with the gas in the second chamber 1120 .

[0079] In some embodiments, a centrifugal pump may be used as the sole power source for circulating the thermal fluid loop.

[0080] In some embodiments, after the heat transfer liquid enters the second chamber 1120 through the heat transfer liquid inlet 1121, it can be forced to circulate using a centrifugal pump. The centrifugal pump can be configured to automatically start when the temperature of the heat transfer oil exceeds a predetermined reaction temperature, thereby maintaining the temperature of the heat transfer oil within the predetermined reaction temperature range.

[0081] In some embodiments, the heat transfer liquid can be thermal oil. The thermal oil has two main functions: during the heating phase, the thermal oil in the second chamber 1120 can assist in heating the oxidant in the first chamber 1110; during the reaction phase, the thermal oil in the second chamber 1120 can be forced to circulate under the action of a centrifugal pump to remove heat from the first chamber 1110, maintaining it within a predetermined reaction temperature range while preventing overheating and coking of the thermal oil in the second chamber 1120.

[0082] In some embodiments, as Figure 2 As shown, the heating assembly 114 includes a first heating element 1141 and a second heating element 1142; the first heating element 1141 is arranged inside the first container body 111, and the extension direction of the first heating element 1141 is parallel to the axial direction of the first container body 111, and is used to heat the oxidant in the first chamber 1110; the second heating element 1142 is arranged inside the second container body 112, and the extension direction of the second heating element 1142 is perpendicular to the axial direction of the first container body 111, and is used to directly heat the heat-conducting liquid in the second chamber 1120, thereby indirectly heating the oxidant in the first chamber 1110; wherein, the heating power of the first heating element 1141 is greater than the heating power of the second heating element 1142.

[0083] The embodiment of the present application heats the oxidant in the first container body 111 and the heat-conducting liquid in the second container body 112 through the first heating element 1141 and the second heating element 1142 respectively, which is beneficial to ensure that the reaction temperature can reach and remain at the predetermined reaction temperature, thereby ensuring that the redox reaction proceeds smoothly.

[0084] In some embodiments, the first heating element 1141 and the second heating element 1142 may be electric heating rods.

[0085] In some embodiments, the heating power of the first heating element 1141 may be 2 kW, and the heating power of the second heating element 1142 may be 0.5 kW.

[0086] In some embodiments, as Figure 2 As shown, a first heating interface 11142 may be formed on the first container body 111. The first heating element 1141 is disposed inside the first container body 111 through the first heating interface 11142.

[0087] In some embodiments, the first heating interface 11142 is formed at the bottom of the cover 1114 of the first container body 111 .

[0088] In some embodiments, Figure 3 is a top view of a sodium processing device according to an embodiment of the present application, as shown in FIG. Figure 2 and Figure 3 As shown, a second heating interface 1123 may be formed on the second container body 112 . The second heating element 1142 is disposed inside the second container body 112 through the second heating interface 1123 .

[0089] In some embodiments, reference Figure 1 The treatment system of the embodiment of the present application further includes a tail gas treatment device 14, which is fluidically connected to the sodium treatment device 11 and is used to treat the tail gas generated during the redox treatment process.

[0090] In the embodiment of the present application, the tail gas treatment device 14 is fluidically connected to the sodium treatment device 11 , which is beneficial for purifying the gas generated during the redox treatment of sodium and avoiding pollution.

[0091] In some embodiments, the seal 1113 further forms an exhaust gas outlet 11132. The exhaust gas outlet 11132 is in fluid communication with the exhaust gas treatment device 14 for discharging the exhaust gas in the first chamber 1110 of the first container body 111 to the exhaust gas treatment device 14, so that the exhaust gas generated during the redox treatment process can be treated by the exhaust gas treatment device 14.

[0092] In some embodiments, the tail gas treatment device 14 may also be in fluid communication with the glass solidification container of the glass solidification device 13 to treat the argon gas in the glass solidification container.

[0093] In some embodiments, the treatment system further includes a pure water device 16 in fluid communication with the exhaust gas treatment device 14 for providing the exhaust gas treatment device 14 with the water required for exhaust gas treatment. The pure water device 16 includes a liquid supply unit and a liquid storage unit. The liquid storage unit is used to store and supply the water required for exhaust gas treatment to the exhaust gas treatment device 14. The liquid storage unit is used to prepare the water required for exhaust gas treatment and transfer it to the liquid storage unit for storage.

[0094] The embodiments of the present application also provide a method for treating radioactive waste sodium, which is applicable to the system for treating radioactive waste sodium of the embodiments of the present application. Figure 4 is a schematic flow chart of a method for treating radioactive waste sodium according to an embodiment of the present application, such as Figure 4 As shown, the method includes the following steps S1 to S4.

[0095] S1. Liquid sodium is delivered to the sodium processing device 11 in the system at a predetermined speed.

[0096] S2. performing redox treatment on the metallic sodium in the liquid sodium to obtain a sodium oxidation product.

[0097] S3. Collect the sodium oxidation products obtained after being processed by the sodium treatment device 11, and transfer the sodium oxidation products to the glass solidification device 13 in the system.

[0098] S4. Under an inert atmosphere, the sodium oxidation product is vitrified to obtain a vitrified material.

[0099] In the embodiment of the present application, liquid sodium is delivered to the sodium treatment device 11 in the system at a predetermined speed to perform redox treatment on the metallic sodium in the liquid sodium, thereby making the reaction process relatively mild and safer. The sodium oxidation products obtained after treatment by the sodium treatment device 11 are then collected and transferred to the vitrification device 13. This can achieve the safe conversion of radioactive waste sodium containing insoluble impurities while achieving the vitrification of the radioactive waste, which is beneficial to ensuring the treatment efficiency of the radioactive waste sodium.

[0100] In some embodiments, step S4 may include: S41, determining a glass component formula of a glass curing agent, where the component formula includes the type of glass component and the mass percentage of each type of glass component in the glass curing agent; S42, determining the mass of a sodium oxidation product and the mass percentage of sodium in the sodium oxidation product; S43, determining the mass of the glass curing agent based on the glass component formula determined in step S41, the mass of the sodium oxidation product determined in step S42, and the mass percentage of sodium in the sodium oxidation product; S44, mixing the glass curing agent obtained in step S43 and the sodium oxide product determined in step S42, and transferring the mixed mixture into a reaction vessel; S45, heating the reaction vessel containing the mixture under an inert atmosphere until the mixture melts; S46, annealing the melt obtained in step S45 to obtain a glass cured product.

[0101] The method provided in the embodiments of the present application determines the mass of the glass curing agent based on the glass component formula of the glass curing agent, the mass of the sodium oxidation product, and the mass percentage of the sodium element in the sodium oxidation product, thereby using the determined glass curing agent to vitrify the sodium oxidation product under an inert atmosphere. The glass curing agent used in this method has a high capacity for the sodium oxidation product, which is beneficial to improving the curing efficiency of the sodium oxidation product containing the sodium element. At the same time, the curing process is safer and the obtained glass cured product is more stable.

[0102] In some embodiments, the reaction container is a corundum crucible. It is understood that the reaction container and the movable container in the embodiments of the present application can be the same crucible.

[0103] In some embodiments, the glass curing agent obtained in step S43 and the sodium oxide product determined in step S42 may be placed in a mortar and fully ground and mixed to obtain a mixture.

[0104] In some embodiments, the material of the mortar can be glass.

[0105] In some embodiments, in the mixture of the glass curing agent and the sodium oxide product, the sum of the mass percentage of the sodium oxide product and the mass percentage of each type of glass component is 100%, so as to ensure the curing effect of the glass curing.

[0106] In some embodiments, the glass curing agent is weighed in a ratio of 55% to 75% by mass and the sodium oxidation product is weighed in a ratio of 25% to 45% by mass, and the weighed product is placed in a glass mortar for grinding.

[0107] In some embodiments, the sodium oxide product includes Fe2O3 and Na2O, wherein the sum of the mass percentages of Fe2O3 and Na2O in the mixture is 25% to 45%.

[0108] In some embodiments, step S45 includes: S451, heating the reaction vessel containing the mixture at a predetermined heating rate under an inert atmosphere; S452, after the heating temperature reaches the predetermined temperature, maintaining the predetermined temperature for a predetermined time to allow the mixture to fully melt.

[0109] The method provided in the embodiments of the present application heats the mixture at a predetermined heating rate under an inert atmosphere, which helps to prevent air from coming into contact with and reacting with the metallic sodium in the mixture, thereby affecting the glass solidification effect of the metallic sodium. After the heating temperature reaches a predetermined temperature, the temperature is maintained for a predetermined period of time, which helps to ensure the melting effect of the melt.

[0110] In some embodiments, the corundum crucible containing the mixture is transferred to a muffle furnace for heating to a predetermined temperature, thereby obtaining a melt.

[0111] In some embodiments, the predetermined temperature is 1100° C. to avoid volatilization as much as possible while achieving a good glass solidification effect.

[0112] In some embodiments, the predetermined time is within the range of 1-3 hours to ensure that the glass is melted more uniformly and the melting effect can meet the requirements.

[0113] In some embodiments, step S46 includes cooling the melt to room temperature to obtain a glass solid.

[0114] In some embodiments, after the melt is obtained in the muffle furnace, the melt may be furnace-cooled until the temperature cools to room temperature.

[0115] In some embodiments, the cooling rate during furnace cooling is 1-3° C. / min.

[0116] In some embodiments, before step S44, the process further includes: cleaning the reaction container and drying the cleaned reaction container to avoid introducing new impurities during the glass solidification process.

[0117] In some embodiments, the reaction container used for melting glass may be cleaned first, and then the cleaned reaction container may be placed in an oven at a predetermined drying temperature for drying.

[0118] In some embodiments, the predetermined drying temperature is 90°C.

[0119] In some embodiments, when the glass component formula is a quaternary formula system, the types of glass components in the glass component formula include SiO2, B2O3, Al2O3 and CaO, wherein the mass percentage of SiO2 is 37%-51%, the mass percentage of B2O3 is 11%-15%, the mass percentage of Al2O3 is 4%-5%, and the mass percentage of CaO is 2%-3%.

[0120] In some embodiments, when the glass component formula is a five-component formula system, the types of glass components in the glass component formula include SiO2, B2O3, Al2O3, CaO and ZrO2, wherein the mass percentage of SiO2 is 35%-48%, the mass percentage of B2O3 is 10%-15%, the mass percentage of Al2O3 is 3%-6%, the mass percentage of CaO is 3%-5%, and the mass percentage of ZrO2 is 2%-3%.

[0121] In some embodiments, when the glass component formula is a sesquivalent formula system, the types of glass components in the glass component formula include SiO2, B2O3, Al2O3, CaO, ZrO2 and LiO2, wherein the mass percentage of SiO2 is 34%-46%, the mass percentage of B2O3 is 10%-15%, the mass percentage of Al2O3 is 3%-5%, the mass percentage of CaO is 3%-4%, the mass percentage of ZrO2 is 2%-3%, and the mass percentage of LiO2 is 1%-2%.

[0122] The embodiments of the present application provide three different formulation systems: quaternary, quinary and hexavalent, which can be used for glass solidification of sodium oxidation products, and have a high capacity for sodium oxidation products, so that the nuclide leaching rate in the glass solid can meet the treatment requirements of sodium oxidation products.

[0123] In some embodiments, due to the dangers of radioactive operations, the radioactive components involved in the glass component formula are replaced with non-radioactive components.

[0124] In some embodiments, the glass component formula provided by the embodiments of the present application can have a capacity of 25-45% for sodium oxidation products.

[0125] The following describes in detail the process of vitrifying a sodium oxide product containing 20% ​​Fe2O3 and 25% Na2O using the vitrification method of the embodiment of the present application, taking a five-element glass formula system containing Fe2O3 (20%) and Na2O (25%) as an example:

[0126] The first step is to clean the corundum crucible used to melt the glass solidification material and place it in an oven for mixing and drying.

[0127] In the second step, according to the specific content of each glass component in the predetermined glass component formula, the glass curing agent and the sodium oxidation product are weighed. The masses of the glass components are: SiO2 (35-48g), B2O3 (10-15g), Al2O3 (3-6g), CaO (3-5g), ZrO2 (2-3g), and the masses of the sodium oxidation products are: Fe2O3 (20g), Na2O (25g), totaling 100g. Among them, the sodium oxidation product is replaced by Fe2O3 (20g) and Na2O (25g), and its inclusion rate is 45%.

[0128] In the third step, the weighed sodium oxidation product and the glass curing agent are placed in a glass mortar and ground thoroughly to mix the two evenly, and then the evenly mixed mixture is transferred to a corundum crucible to be used.

[0129] In the fourth step, the corundum crucible was transferred to a muffle furnace in an oxidizing atmosphere, and the temperature was increased to 1100°C at a heating rate of 5°C / min, and then the heating was stopped after being kept at 1100°C for 1 hour.

[0130] The fifth step is to anneal the molten glass at a rate of 1-3°C / min until the temperature drops to room temperature, thereby obtaining a glass solid.

[0131] The following describes a process for treating slag-containing sodium oxidation products using the system and method of the embodiments of the present application based on specific examples.

[0132] Example

[0133] (1) Radioactive waste sodium containing slag is placed in a sodium storage container, which is then connected to the first container body 111 of the sodium processing device 11 through a sodium delivery pipe. At the same time, iron oxide powder is added to the first container body 111, and then the first chamber 1110 of the first container body 111 is vacuum-exchanged with argon gas.

[0134] (2) After the vacuuming is completed, the sodium storage container and the sodium delivery pipe are heated, and a glass curing agent is added to the glass curing container. The iron oxide powder is heated by the heating component 114, and the iron oxide powder is fluidized by the inert gas buffer container 15.

[0135] (3) When the liquid sodium is heated to 400°C and the temperature in the first chamber 1110 is maintained between 380°C and 390°C, the liquid sodium in the sodium storage container is added to the first chamber 1110 at a certain flow rate through the pressure vessel until the 5 kg of sodium is completely reacted. The sodium is dripped into the first chamber 1110 in the form of droplets through the sodium delivery portion of the first container body 111 to undergo a redox reaction. During the reaction, the heat of the reaction must be removed in a timely manner to ensure that the reaction temperature does not exceed the temperature range at the start of the reaction.

[0136] (4) After the reaction is completed and the temperature in the first chamber 1110 drops to room temperature, the lid is opened to transfer the sodium oxidation product to the crucible (movable container) through the movable part. The crucible is then transferred to the glass solidification container and the glass solidification container is covered with argon. The temperature is then raised to 1100°C according to a predetermined heating program and kept warm for 1-3 hours to ensure uniform melting of the glass.

[0137] (5) After the glass is melted, the glass is cooled and annealed at a cooling rate of 1-3°C / min. When the temperature drops to room temperature, a glass solid can be obtained.

[0138] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0139] The above description is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A system for treating radioactive waste sodium, characterized in that: It includes: Sodium Storage, sodium handling, transfer and vitrification equipment, The sodium storage device is used to store radioactive waste sodium to be processed and is configured to deliver liquid sodium to the sodium processing device at a predetermined speed; The sodium processing device is used to receive the liquid sodium and perform oxidation-reduction treatment on the metallic sodium in the liquid sodium to obtain a sodium oxidation product; The transfer device is used to collect the sodium oxidation product obtained after being treated by the sodium treatment device, and transfer the sodium oxidation product to the glass solidification device; The glass solidification device is used to perform glass solidification on the sodium oxidation product under an inert atmosphere to obtain a glass solidified material.

2. The system according to claim 1, characterized in that The sodium processing device comprises: A first container body, wherein the first container body is formed with a first chamber, the first chamber is used to contain the liquid sodium and an oxidant that undergoes an oxidation-reduction reaction with the liquid sodium, and provides a reaction space for the oxidation-reduction reaction; The first container body is connected to the sodium storage device to receive the liquid sodium transported from the sodium processing device; A second container body, wherein the second container body is arranged outside the first container body to form a second chamber with an outer wall of the first container body, and the top and the bottom of the first container body respectively extend outward along the second container body, and is used to heat the first chamber in a heating state, and at the same time, is used to remove reaction heat of the first chamber in the redox reaction state; a plurality of barrier members, wherein the plurality of barrier members are respectively arranged in the first chamber of the first container body, and one barrier member is arranged near the top of the first chamber, and another barrier member is arranged near the bottom of the first chamber, The barrier is used to block the reactants in the redox reaction; A heating component is partially disposed outside the first container body and partially disposed outside the second container body, and is used to heat the first chamber of the first container body and the second chamber of the second container body.

3. The system according to claim 2, characterized in that The first container body comprises a first shell, a second shell, a sealing member, and a cover member; The first end of the first shell is connected to the sealing member, and the second end of the first shell forms a funnel-shaped opening; The first shell forms a sodium transport portion, and the sodium storage device is connected to the first shell through the sodium transport portion; The first end of the second shell is connected to the second end of the first shell, and the second end of the second shell is connected to the cover. The cover is used to open or close the first chamber, wherein the cover is configured to: when opened, the sodium oxidation product can be removed from the first chamber, and when closed, the cover can seal the first chamber.

4. The system according to claim 3, characterized in that One of the blocking members is disposed at a position where the first end of the first shell is connected to the sealing member, and the other of the blocking members is disposed at a position where the second end of the second shell is connected to the cover member.

5. The system according to claim 4, characterized in that The cover is formed with an air inlet, and the air inlet is used to transport an inert gas into the first chamber.

6. The system according to claim 5, characterized in that The sealing member forms a gas flow opening, The gas flow port is used to evacuate the first chamber during the process of conveying inert gas into the first chamber, so as to replace the gas in the first chamber and avoid air residue.

7. The system according to claim 2, characterized in that The second container body is formed with a heat conduction liquid inlet and a heat conduction liquid outlet. The heat-conducting liquid inlet and the heat-conducting liquid outlet are respectively arranged on opposite sides of the second container body, and the heat-conducting liquid outlet is relatively arranged above the heat-conducting liquid inlet, so that when the heat-conducting liquid flows from the heat-conducting liquid inlet to the heat-conducting liquid outlet, convection is formed with the gas in the second chamber, and gas residue is prevented in the second chamber.

8. The system according to claim 7, characterized in that The heating assembly includes a first heating element and a second heating element; The first heating element is disposed inside the first container body, and an extension direction of the first heating element is parallel to an axial direction of the first container body, and is used to heat the oxidant in the first chamber; The second heating element is disposed inside the second container body, and an extension direction of the second heating element is perpendicular to an axial direction of the first container body, and is used to directly heat the heat-conducting liquid in the second chamber, thereby indirectly heating the oxidant in the first chamber; Wherein, the heating power of the first heating element is greater than the heating power of the second heating element.

9. The system according to claim 1, characterized in that Also includes: Exhaust gas treatment device, The tail gas treatment device is fluidically connected to the sodium treatment device and is used to treat the tail gas generated during the oxidation-reduction treatment process.

10. The system according to claim 1, characterized in that Also includes: Inert gas buffer container, The inert gas buffer container is fluidly connected to the sodium processing device and the glass solidification device, respectively, and is used to transport the inert gas to the sodium processing device and the glass solidification device, respectively.

11. A method for treating radioactive waste sodium, which is applicable to the system according to any one of claims 1 to 10, characterized in that: It includes the following steps: S1, delivering liquid sodium to the sodium processing device in the system at a predetermined speed; S2, performing an oxidation-reduction treatment on the metallic sodium in the liquid sodium to obtain a sodium oxidation product; S3, collecting the sodium oxidation product obtained after being treated by the sodium treatment device, and transferring the sodium oxidation product to a glass solidification device in the system; S4. Under an inert atmosphere, the sodium oxidation product is subjected to glass solidification to obtain a glass solidified material.

12. The method according to claim 11, characterized in that The S4 step includes: S41, determining a glass component formula of a glass curing agent, wherein the component formula includes types of glass components and mass percentages of each type of glass components in the glass curing agent; S42, determining the mass of the sodium oxidation product and the mass percentage of the sodium element in the sodium oxidation product; S43, determining the mass of the glass curing agent according to the glass component formula determined in step S41, the mass of the sodium oxidation product determined in step S42, and the mass percentage of the sodium element in the sodium oxidation product; S44, mixing the glass curing agent obtained in step S43 and the sodium oxidation product determined in step S42, and transferring the mixed mixture into a reaction container; S45, heating the reaction container containing the mixture under an inert atmosphere until the mixture is melted; S46, annealing the melt obtained in step S45 to obtain the glass solidified material.

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