Simulation test device and simulation test method for sodium combustion

Abstract

The embodiment of the present invention discloses a simulation test device for sodium combustion. It includes: a sodium delivery tank, in which liquid metal sodium containing radioactive fission product simulation substances is temporarily stored; a combustion container, which is connected to the sodium delivery tank through a sodium transmission pipe, and the sodium transmission pipe is used to transmit the liquid metal sodium in the sodium delivery tank to the combustion container. A drainage pipe is arranged in the combustion container, and the drainage pipe passes through the side wall of the combustion container and is connected to the transmission pipeline; a combustion disk is arranged at the inner center position of the combustion container, and the drainage pipe is used to drain the liquid metal sodium transported by the sodium transmission pipe into the combustion disk, so that the liquid metal sodium contacts the air in the combustion disk and burns to produce an aerosol containing a simulation substance; a plurality of sampling tables are fixed on the inner wall of the combustion container, and a sampling sheet is placed on the sampling table to collect the diffused and deposited aerosol. In addition, the present invention also provides a simulation test method for simulating and verifying the release of radioactive fission products during sodium combustion.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of reactor technology, and in particular to a simulation test device and a simulation test method for sodium combustion. Background Art

[0002] Liquid metal sodium is a commonly used coolant in fast neutron reactors. When a serious accident such as sodium leakage occurs in a sodium-cooled fast reactor, sodium comes into contact with air and burns to produce sodium aerosol. The radioactive fission products contained in the sodium will be released into the containment or the environment along with the sodium aerosol, causing radioactive pollution to the environment. Especially in accidents involving core damage, there are many types of radioactive sources in sodium, and the release behavior of radioactive fission products will be affected by factors such as combustion, condensation, and chemical reactions, making it difficult for researchers to understand the migration and deposition behavior of radioactive fission products. Summary of the invention

[0003] According to one aspect of the present invention, a simulation test device for sodium combustion is provided. The device is used to simulate the release of radioactive fission products during sodium combustion, and comprises: a sodium delivery tank, in which liquid metal sodium containing a simulated substance of radioactive fission products is temporarily stored; a combustion container, which is connected to the sodium delivery tank through a sodium transmission pipe, and the sodium transmission pipe is used to transmit the liquid metal sodium in the sodium delivery tank to the combustion container; wherein a drainage pipe is provided in the combustion container, and the drainage pipe passes through the side wall of the combustion container and is connected to the transmission pipeline; a combustion disk is provided at the inner center of the combustion container, and the drainage pipe is used to drain the liquid metal sodium transported by the sodium transmission pipe into the combustion disk, so that the liquid metal sodium contacts the air in the combustion disk and burns to produce an aerosol containing the simulated substance; a plurality of sampling tables are fixed on the inner wall of the combustion container, and sampling sheets are placed on the sampling tables to collect the diffused and deposited aerosols.

[0004] According to another aspect of the present invention, a simulation test method is provided. The method is used to simulate and verify the release of radioactive fission products during sodium combustion, and the method can be implemented using the simulation test device described in any one of the embodiments. The method includes: heating a sodium delivery tank, a combustion container, and a sodium transmission pipe between the sodium delivery tank and the combustion container; when the temperature of the sodium delivery tank, the combustion container, and the sodium transmission pipe meets the preset conditions, controlling the liquid metal sodium containing radioactive fission product simulation substances in the sodium delivery tank to be transported to the combustion disk of the combustion container, and the liquid metal sodium contacts the air in the combustion disk and starts to burn, forming an aerosol containing the simulation substance; when the combustion is complete, stopping the heating and leaving the combustion container to stand, so that the aerosol in the combustion container is deposited; when the aerosol is completely deposited, taking out the sampling piece in the combustion container and the sodium oxide generated after the liquid metal sodium in the combustion disk is burned; according to the simulation substance and the sodium oxide in the aerosol deposited on the sampling piece, analyzing the release law of the simulation substance in the sodium combustion process. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Other objects and advantages of the present invention will become apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.

[0006] Figure 1 It is a schematic structural diagram of a combustion container according to an embodiment of the present invention.

[0007] Figure 2 1 is a schematic diagram of the structure of a sodium delivery tank according to an embodiment of the present invention.

[0008] Figure 3 yes Figure 2 Schematic diagram of the structure of the intermediate sodium tank from another perspective.

[0009] Figure 4 is a schematic diagram of a simulation test device according to an embodiment of the present invention.

[0010] Figure 5 It is a flowchart of a simulation test method according to an embodiment of the present invention.

[0011] 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.

[0012] Description of reference numerals:

[0013] 100, combustion container; 110, main body; 111, observation window; 112, insulation layer; 120, sealing cover; 121, exhaust port; 122, first pressure monitoring member; 123, first fastener; 130, bottom; 131, discharge port; 140, support seat;

[0014] 10. Drainage tube; 20. Combustion plate; 21. Support part; 30. Sampling table;

[0015] 210, sodium delivery tank; 211, discharge port; 212, sodium discharge pipe; 213, sodium inlet pipe; 214, liquid level measuring component; 215, delivery port; 216, second pressure monitoring component; 220, bracket; 230, second fastener;

[0016] 310, spraying parts; 320, water storage tank; 330, alkali liquid tank; 340, alkali liquid pump;

[0017] 410. Heating element;

[0018] 500, sodium transmission tube;

[0019] 600. Vacuum pump;

[0020] 700. Inert gas storage tank. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiment is one embodiment of the present application, not all embodiments. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should be the usual meanings understood by people with general skills in the field to which this application belongs. If the full text involves descriptions such as "first" and "second", the descriptions such as "first" and "second" are only used to distinguish similar objects, and cannot be understood as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data described by "first" and "second" can be interchangeable under appropriate circumstances. If "and / or" appears in the full text, its meaning is to include three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, for the convenience of description, spatial relative terms such as "above", "below", "top", "bottom", etc. can be used here, which are only used to describe the spatial position relationship between a device or feature as shown in the figure and other devices or features, and should be understood to also include different orientations in use or operation except for the orientation shown in the figure.

[0023] The embodiment of the present invention provides a sodium combustion simulation test device, which can simulate the release behavior of radioactive fission products contained in liquid metal sodium during the combustion process, and conduct simulation test research on the migration, deposition, gravity sedimentation and other behaviors of the radioactive fission products, thereby accumulating basic data on the release of radioactive fission products in liquid metal sodium during sodium combustion, and deepening the understanding and recognition of the accident process of sodium-cooled fast reactors.

[0024] The sodium combustion simulation test device in this embodiment includes a combustion container 100 and a sodium delivery tank 210. Liquid metal sodium containing radioactive fission product simulation substances is temporarily stored in the sodium delivery tank 210. Figure 4 As shown, the combustion container 100 is connected to the sodium delivery tank 210 via a sodium delivery pipe 500 , and the sodium delivery pipe 500 is used to deliver the liquid metallic sodium containing the simulated substance in the sodium delivery tank 210 to the combustion container 100 . Figure 1 FIG. 2 shows a schematic diagram of the structure of a combustion container according to an embodiment of the present invention. Figure 1 In this embodiment, a drainage pipe 10 is provided in the combustion container 100, and the drainage pipe 10 passes through the side wall of the combustion container 100 and is connected to the sodium transmission pipe 500. A combustion disk 20 is provided at the center of the combustion container 100, and the drainage pipe 10 is used to drain the liquid metal sodium transported by the sodium transmission pipe 500 into the combustion disk 20, so that the liquid metal sodium contacts the air in the combustion disk 20 and burns to generate an aerosol containing the simulated substance. In addition, a plurality of sampling tables 30 are provided on the inner wall of the combustion container 100, and a sampling sheet is placed on the sampling table 30 to collect the aerosol containing the simulated substance diffused and deposited on its surface.

[0025] In this embodiment, a combustion disk 20 is arranged at the center position inside the combustion container 100, and liquid metallic sodium is introduced into the combustion disk 20 through the drainage tube 10. The liquid metallic sodium containing the simulated substance burns in the combustion disk 20 located at the center position, so that the sodium aerosol containing the simulated substance formed after the sodium burns can diffuse to the surroundings. The sampling pieces on the multiple sampling tables 30 arranged at different positions on the inner wall of the combustion container 100 can collect the sodium aerosol deposited thereon. By analyzing the simulated substance in the sodium aerosol collected by the sampling pieces on the sampling tables 30 at different positions, the release, migration and deposition behavior of the radioactive fission products can be inferred, which is convenient for studying the release mechanism of the fission products during the sodium combustion process.

[0026] It should be noted that the radioactive fission product simulating substance in the embodiment of the present invention is a substance that is non-radioactive and has the same or similar properties as the radioactive fission product, and can be used to simulate the release behavior of the radioactive fission product while ensuring the safety of the test personnel. In this embodiment, the radioactive fission product simulating substance can be cesium iodide.

[0027] By using the simulation test device provided in this embodiment, the release, migration and deposition process of radioactive fission products during sodium combustion can be simulated safely and reliably. The operation is convenient and the sodium combustion test process will not cause harm to the test personnel.

[0028] In this embodiment, if Figure 1 As shown, a support portion 21 is fixed on the inner wall of the combustion container 100, and the combustion disk 20 is placed on the support portion 21, which is convenient for taking out and replacing the combustion disk 20. Specifically, the combustion disk 20 is in the shape of a disk, which is placed on the support portion 21, and liquid metal sodium burns in the combustion disk to simulate pool-type sodium combustion. The combustion disk 20 can be taken out after the sodium combustion test is completed to achieve sampling and analysis of sodium oxides containing simulated substances formed after the sodium combustion.

[0029] Optionally, the drainage tube 10 is fixed to the side wall of the combustion container 100, for example, the drainage tube 10 is fixed to the side wall of the combustion container 100 by welding. In some embodiments, the outlet of the drainage tube 10 corresponds to the center position of the combustion disk 20. The support portion 21 can be fixedly connected below the drainage tube 10, so that while the support portion 21 is fixed, the combustion disk 20 can be ensured to be located below the outlet of the drainage tube 10, so that the liquid metal sodium can be accurately introduced into the combustion disk 20.

[0030] Optionally, a support plate is fixed on the inner wall of the combustion container 100, and the combustion disk 20 is placed on the support plate. For example, the support plate can be fixed to the inner wall of the combustion container 100 by welding. In this embodiment, the connection between the support plate and the combustion container 100 needs to avoid the sampling table 30 provided on the inner wall of the combustion container 100 to prevent the support plate from affecting the deposition of aerosol on the sampling table 30. In this embodiment, the installation height of the support plate in the combustion container 100 can be lower than the installation height of the sampling table 30.

[0031] See also Figure 1 In this embodiment, there are multiple sampling stations 30, and the multiple sampling stations 30 are distributed on the inner wall of the combustion container 100 along the axial direction of the combustion container 100, so that the aerosol diffused to different heights is deposited on each sampling station 30, and the aerosol diffused to different heights is sampled. And / or, the multiple sampling stations 30 are distributed on the inner wall of the combustion container 100 along the circumferential direction of the combustion container 100, so that the aerosol diffused to different angles is deposited on each sampling station 30, and the aerosol diffused to different angles is sampled.

[0032] In this embodiment, by setting the sampling stations 30 at different positions inside the combustion container 100, it is possible to sample the aerosol diffused to different positions, so as to study the diffusion and gravity sedimentation behavior of the aerosol containing the simulated substance, and further study the release mechanism of the radioactive fission material. For example, three sampling stations 30 are distributed on the inner wall of the combustion container 100 along the axial direction of the combustion container 100, and four sampling stations 30 are distributed on the inner wall of the combustion container 100 along the circumferential direction of the combustion container 100.

[0033] In this embodiment, a sampling sheet is placed on the sampling table 30, and the aerosol diffuses and deposits on the outer surface of the sampling sheet, so as to facilitate the removal and replacement of the sampling sheet. The sampling sheet is provided with a hook portion, which is configured to be hooked by a sampling tool to put the sampling sheet into or take it out of the sampling table in the combustion container 100. Specifically, the hook portion on the sampling sheet can be a ring provided on the sampling sheet, and the sampling tool can be a dedicated sampling hook. By using the cooperation between the sampling hook and the ring on the sampling sheet, the sampling sheet can be taken out from the combustion container 100, so as to facilitate the analysis of the aerosol containing the simulated substance deposited on the sampling sheet.

[0034] like Figure 1 As shown, the combustion container 100 in this embodiment includes a main body 110, a sealing cover 120 and a bottom 130. The sealing cover 120 and the bottom 130 are detachably connected to the main body 110. The sealing cover 120 is detachably connected to the main body 110, so that the combustion container 100 can be opened, which is convenient for taking out the combustion disk 20 and the sampling sheet, and realizing the sampling analysis of the aerosol and the sodium oxide. Specifically, the sealing cover 120 can be detachably connected to the main body 110 by a first fastener 123 (for example, a bolt, etc.), so as to facilitate the disassembly and installation of the combustion container 100.

[0035] In this embodiment, an exhaust port 121 is provided on the sealing cover 120, and an aerosol filter is installed on the exhaust port 121. The aerosol filter is configured to allow air to pass through but not allow particulate matter such as aerosols to pass through, thereby achieving communication between the interior of the combustion container 100 and the external atmosphere, so that the interior of the combustion container 100 is filled with air, so that the liquid metallic sodium flowing into the combustion disk 20 can contact the air and burn, while preventing sodium aerosol containing radioactive fission product simulation substances from being discharged into the atmosphere from the exhaust port 121 to pollute the environment.

[0036] like Figure 1As shown, the combustion container 100 in this embodiment is provided with an observation window 111. The observation window 111 is provided on the side wall of the combustion container 100 (i.e., the main body 110 of the combustion container 100), and the observation window 111 is located at the same height as the combustion disk 20 inside the combustion container 100, so that the test personnel can observe the entire sodium combustion test process through the observation window 111, and can also record the sodium combustion process through the observation window 111, which is conducive to the study of the sodium combustion process.

[0037] In some embodiments, the observation window 111 can be formed by sealingly connecting quartz glass of a certain thickness to the side wall of the combustion container 100. The quartz glass observation window 111 has good high temperature resistance and optical properties, is not easily damaged when used at high temperatures during the sodium combustion process, and can clearly observe the sodium combustion process.

[0038] In addition, a first pressure monitoring component 122 is provided on the sealing cover 120 of the combustion container 100. The first pressure monitoring component 122 is used to monitor the gas pressure inside the combustion container 100. The test personnel can use the first pressure monitoring component 122 to record the pressure inside the combustion container 100 during the sodium combustion process.

[0039] The test device in this embodiment also includes a cleaning component, so that after the simulation test is completed, the aerosol adhering to the inner wall of the combustion container 100 can be cleaned.

[0040] See also Figure 1 and Figure 4 The cleaning component includes a spray part 310, a water tank 320 and an alkali liquid tank 330. The spray part 310 is arranged on the sealing cover 120 of the combustion container 100 and extends into the combustion container 100, and is used for spraying and cleaning the aerosol adhered to the inner wall of the combustion container 100. The water tank 320 stores water, and the spray part 310 is connected to the water tank 320. The water in the water tank 320 can be transported to the spray part 310 to clean the inner wall of the combustion container 100. The sodium aerosol generated by the combustion of sodium in the air is generally sodium oxide, and water can react with the sodium aerosol to generate a sodium hydroxide solution, so that the sodium aerosol adhered to the inner wall of the combustion container is dissolved in the water to form an alkali solution, thereby cleaning the inner wall of the combustion container 100.

[0041] The alkali liquid tank 330 is located below the combustion container 100. A discharge port 131 is provided on the bottom 130 of the combustion container 100. The discharge port 131 is connected to the alkali liquid tank 330. The discharge port 131 is used to discharge the alkali liquid formed after cleaning the inner wall of the combustion container 100 into the alkali liquid tank 330. The alkali liquid tank 330 is used to collect and store the alkali liquid.

[0042] In this embodiment, the alkali liquid tank 330 is arranged below the combustion container 100. During the cleaning process, the discharge port 131 arranged at the bottom of the combustion container 100 can be opened, so that the alkali liquid generated after cleaning can flow into the alkali liquid tank 330 below the combustion container 100 through the discharge port 131 at the bottom by its own gravity, and the alkali liquid can be collected without setting up additional mechanical equipment (for example, a pump, etc.).

[0043] In some embodiments, the spray part 310 can also be connected to the alkali liquid tank 330, and the alkali liquid stored in the alkali liquid tank 330 can be transported to the spray part 310, so as to use the stored alkali liquid to clean the inner wall of the combustion container 100. Specifically, when the combustion container 100 is cleaned for the first time, the water in the water storage tank 320 can be used to spray and clean the inner wall of the combustion container 100, and the alkali liquid generated after cleaning is collected from the discharge port 131 at the bottom of the combustion container 100 into the alkali liquid tank 330. In the subsequent cleaning process, the alkali liquid collected in the alkali liquid tank 330 can be used to continue to clean the combustion container 100, that is, the combustion container 100 is circulated and cleaned using the alkali liquid, so as to realize the recycling of the alkali liquid and save the cost of the test.

[0044] In some embodiments, a lye pump 340 is provided on the connecting pipe between the spray element 310 and the water storage tank 320 , which can transport water in the water storage tank 320 to the spray element 310 to achieve cleaning of the combustion container 100 .

[0045] Furthermore, the water outlet of the alkali liquid tank 330 can be connected to the water inlet of the alkali liquid pump 340 through a connecting pipe, so that when the alkali liquid collected in the alkali liquid tank 330 is used for cleaning, the same alkali liquid pump 340 can be used to transport the alkali liquid in the alkali liquid tank 330 to the spray part 310, without setting up an additional pump, thereby saving costs.

[0046] Optionally, the spray member 310 in this embodiment can be a spray pipe, the water inlet end of the spray pipe is located outside the combustion container 100, and is connected to the water outlet of the alkali solution pump 340. The water spray port of the spray pipe is located inside the combustion container 100, and the water spray port of the spray pipe is distributed along the circumferential direction of the spray pipe, so that the spray pipe can spray water all around. The spray pipe in this embodiment is configured to spray water or alkali solution all around in a radial shape, so that the spray cleaning of the inner wall of the entire combustion container 100 is achieved through one spray pipe.

[0047] In addition, the test device in this embodiment further includes a support base 140 , and the main body 110 of the combustion container 100 is fixed on the support base 140 , and the combustion container 100 is supported on an external test platform or the ground through the support base 140 .

[0048] Figure 2 and Figure 3FIG. 2 shows a schematic diagram of the structure of a sodium delivery tank according to an embodiment of the present invention. Figure 2 The sodium delivery tank 210 in this embodiment is installed on the bracket 220 to support the sodium delivery tank 210 on the ground or the test platform to prevent the bottom of the sodium delivery tank 210 from contacting the ground or the test platform, so as to facilitate the liquid metal sodium in the sodium delivery tank 210 to be transported from the bottom of the sodium delivery tank 210 to the combustion container 100. In this embodiment, the bracket 220 can be a stainless steel bracket, which has high strength and high temperature resistance, and can stably support the high temperature sodium delivery tank 210.

[0049] In some embodiments, the sodium delivery tank 210 is further provided with a second fastener 230, and the second fastener 230 is used to fix the sodium delivery tank 210 to the bracket 220. Specifically, the second fastener 230 in this embodiment can be a fastening bolt, which is arranged at the top of the sodium delivery tank 210. By tightening or loosening the fastening bolt, the sodium delivery tank 210 and the bracket 220 can be fixed and disassembled. In this embodiment, the second fastener 230 is arranged at the center of the top of the sodium delivery tank 210, so that the top of the sodium delivery tank 210 is evenly stressed, and the sodium delivery tank 210 is more stably fixed in the bracket 220.

[0050] like Figure 2 As shown, in this embodiment, a discharge port 211 is provided at the bottom of the sodium delivery tank 210, and a sodium discharge pipe 212 is provided at the discharge port 211. The sodium discharge pipe 212 is connected to the sodium transmission pipe 500, so that the liquid metallic sodium containing the simulated substance in the sodium delivery tank 210 can be transported to the interior of the combustion container 100.

[0051] See also Figure 4 A valve is provided on the sodium transmission pipe 500 between the sodium delivery tank 210 and the combustion container 100. By opening or closing the valve, the connection or blocking between the sodium delivery tank 210 and the combustion container 100 can be achieved, thereby controlling the sodium delivery tank 210 to deliver or stop delivering liquid metallic sodium to the combustion container 100.

[0052] In addition, the sodium transmission pipe 500 between the sodium delivery tank 210 and the combustion container 100 is connected by a pipe connector (eg, a flexible joint), so that the sodium transmission pipe 500 can be quickly connected or disconnected.

[0053] In some embodiments, a weighing piece is further provided below the sodium delivery tank 210, and the weighing piece is used to weigh the total mass of the sodium delivery tank 210 and the liquid metallic sodium in the sodium delivery tank 210, and then when the sodium delivery tank 210 delivers the liquid metallic sodium to the combustion container 100, the mass of the liquid metallic sodium containing the simulated substance delivered to the combustion container 100 can be weighed, and the quantitative delivery of the liquid metallic sodium is achieved to control the amount of the liquid metallic sodium used in the sodium combustion test. Specifically, the weighing piece can be an electronic scale provided below the sodium delivery tank 210, which can accurately weigh the delivery mass of the liquid metallic sodium.

[0054] In addition, a sodium inlet pipe 213 is also provided on the top of the sodium delivery tank 210 in this embodiment, through which liquid metallic sodium can be input into the sodium delivery tank 210, thereby achieving mixing of the liquid metallic sodium and the simulated substance of the radioactive fission product in the sodium delivery tank 210.

[0055] Furthermore, the weighing member can also weigh the mass of the liquid metallic sodium input into the sodium delivery tank 210 when delivering sodium into the sodium delivery tank 210, thereby ensuring the amount of sodium input into the sodium delivery tank 210 during the delivery process and preventing overflow due to excessive sodium input.

[0056] like Figure 2 and 3 As shown, a liquid level measuring member 214 is installed on the top of the sodium delivery tank 210 in this embodiment, and the measuring end of the liquid level measuring member 214 is inserted into the sodium delivery tank 210 to monitor the liquid level of the liquid metallic sodium in the sodium delivery tank 210, so that the high liquid level of the liquid metallic sodium can be monitored in real time when the liquid metallic sodium is input into the sodium delivery tank 210. When the liquid metallic sodium reaches the top of the sodium delivery tank 210, the measuring end of the liquid level measuring member 214 can detect the liquid metallic sodium level and display it on the instrument outside the sodium delivery tank 210, so that the test personnel can stop the input of sodium in time.

[0057] Specifically, the liquid level measuring member 214 may be a probe liquid level meter, the probe of which extends into the sodium delivery tank 210 to measure the liquid level of the liquid metallic sodium in the sodium delivery tank 210 .

[0058] In this embodiment, a liquid level measuring member 214 is provided on the sodium delivery tank 210 to measure the liquid level of the liquid metallic sodium in the sodium delivery tank 210. When the liquid metallic sodium is delivered to the sodium delivery tank 210, damage to the weighing member and inability to know the input liquid level of the liquid metallic sodium in the sodium delivery tank 210 can be avoided, thereby preventing excessive input of sodium.

[0059] See also Figure 3The top of the sodium delivery tank 210 is provided with a delivery port 215, which is used to deliver the simulated material of the radioactive fission product into the sodium delivery tank 210 to mix with the liquid metallic sodium in the sodium delivery tank 210. In this embodiment, the delivery port 215 can be selectively opened or closed. When the simulated material needs to be delivered, the delivery port is opened to deliver the simulated material. After the delivery is completed, the delivery port is closed in time, so that a large amount of air can be prevented from entering the sodium delivery tank, thereby preventing the liquid metallic sodium from contacting the air and being oxidized or even burned.

[0060] The simulated substance of the radioactive fission product may be cesium iodide, etc. Before being added, the mass of the simulated substance may be weighed in advance, and a certain amount of the simulated substance may be added to the sodium delivery tank 210, so as to facilitate the study of the release behavior of the simulated substance during the sodium combustion process.

[0061] like Figure 3 As shown, the sodium inlet tube 213 , the liquid level measuring component 214 and the injection port 215 in this embodiment are distributed around the second fastener 230 .

[0062] like Figure 4 As shown, the test device in this embodiment also includes a vacuum system and an inert gas system. Among them, the vacuum system includes a vacuum pump 600, and the inert gas system includes an inert gas storage tank 700. The vacuum pump 600 is connected to the sodium delivery tank 210, and is used to extract the gas in the sodium delivery tank 210 to make it in a vacuum state. Inert gas is stored in the inert gas storage tank 700, and the inert gas storage tank 700 is connected to the sodium delivery tank 210, so as to input inert gas into the sodium delivery tank 210. The gas in the sodium delivery tank 210 can be replaced with inert gas by the vacuum pump 600 and the inert gas storage tank 700, so that the water and oxygen concentrations in the sodium delivery tank 210 meet the requirements of liquid metallic sodium, and liquid metallic sodium can be input into the sodium delivery tank 210. For example, the inert gas storage tank 700 in this embodiment is an argon gas bottle, which stores argon gas, and is used to replace the gas in the sodium delivery tank 210 with inert argon gas to protect the liquid metallic sodium.

[0063] Furthermore, the test device in this embodiment further includes a sodium storage tank. Liquid metallic sodium is stored in the sodium storage tank, and the sodium storage tank is used to transport the liquid metallic sodium to the sodium delivery tank 210 when the interior of the sodium delivery tank 210 is filled with inert gas, so as to achieve mixing with the simulated substance of the radioactive fission product.

[0064] In addition, the inert gas storage tank 700 in this embodiment is also connected to the sodium storage tank, and gas is introduced into the sodium storage tank through the inert gas storage tank 700. The pressure of the inert gas is used to drive the liquid metallic sodium stored in the sodium storage tank to be transported to the sodium transport tank 210.

[0065] The inert gas system in this embodiment also includes a pressure reducing valve, a safety valve, a stop valve, and a gas pipeline between the inert gas storage tank 700 and the sodium delivery tank 210 and the sodium storage tank. Among them, the pressure reducing valve is installed on the inert gas storage tank 700 to control the outlet pressure and gas flow of the inert gas storage tank 700. The safety valve is arranged on the gas branch road led out of the gas pipeline, and is used to prevent the pressure in the gas pipeline from exceeding the specified value by discharging the inert gas to the outside when the pressure reducing valve is not well controlled and the pressure in the gas pipeline is too high. The stop valve is arranged on the gas pipeline to control the connection or blocking of the gas pipeline, so as to control the start and stop of the input of inert gas to the sodium delivery tank 210 or the sodium storage tank.

[0066] The vacuum system in this embodiment further includes a vacuum valve and a vacuum pipeline between the sodium delivery tank 210 and the vacuum pump 600. The vacuum valve is installed on the vacuum pipeline between the sodium delivery tank 210 and the vacuum pump 600 to control the connection and isolation between the vacuum pump 600 and the sodium delivery tank 210, thereby controlling the start and stop of vacuuming the sodium delivery tank 210.

[0067] See also Figure 2 and Figure 3 In this embodiment, a second pressure monitoring component 216 is further provided on the top of the sodium delivery tank 210. The second pressure monitoring component 216 can monitor the gas pressure inside the sodium delivery tank 210, so that after the vacuum pump 600 and the inert gas storage tank 700 cooperate to replace the gas in the sodium delivery tank 210, it is ensured that the interior of the sodium delivery tank 210 is in a slightly positive pressure state of the inert gas, ensuring that the sodium delivery tank 210 is under the protection of the inert gas.

[0068] In some embodiments, the test device further includes a plurality of heating components. Each heating component is respectively disposed on the combustion container 100, the sodium delivery tank 210 and the sodium transmission tube 500 to achieve heating of the combustion container 100, the sodium delivery tank 210 and the sodium transmission tube 500 and feedback, control and maintenance of the heating temperature.

[0069] Specifically, the heating assembly includes a heating element 410 and a temperature monitoring element. The heating element 410 is disposed on the outer wall of the combustion container 100, the sodium delivery tank 210, the drainage pipe 10 or the sodium transmission pipe 500, and is used to heat the combustion container 100, the sodium delivery tank 210, the drainage pipe 10 and the sodium transmission pipe 500 to prevent liquid metal sodium from solidifying in the combustion container 100, the sodium delivery tank 210, the drainage pipe 10 and the sodium transmission pipe 500. For example, the heating element 410 can be a heating wire or a heating mesh.

[0070] The temperature monitoring component is arranged on the combustion container 100, the sodium delivery tank 210, the drainage pipe 10 or the sodium transmission pipe 500, and is used to monitor the temperature of the outer wall of the combustion container 100, the sodium delivery tank 210, the drainage pipe 10 or the sodium transmission pipe 500. The heating element 410 in this embodiment can also control its own heating temperature according to the monitored temperature feedback, so that the combustion container 100, the sodium delivery tank 210 or the sodium transmission pipe 500 is at a predetermined temperature. For example, the temperature monitoring component can be a thermocouple, which can accurately measure the temperature of the outer wall of each device.

[0071] See also Figure 1 The main body 110 and the outer wall of the bottom 130 of the combustion container 100 are provided with a heating element 410, so as to heat the combustion container 100, so that the interior of the combustion container 100 is at a certain temperature, and the liquid metal sodium flowing into the combustion disk 20 can be burned at the temperature. Similarly, the outer wall of the sodium delivery tank 210 and the sodium transmission pipe 500 is also provided with a heating element, so as to heat the sodium delivery tank 210 and the sodium transmission pipe 500, so as to prevent the liquid metal sodium therein from solidifying and causing the pipe to be blocked.

[0072] In this embodiment, the heating assembly includes at least one temperature monitoring component, which is disposed on the combustion container 100, wherein a measuring end of one temperature monitoring component is inserted into the combustion container 100 to monitor the temperature inside the combustion container 100. At the same time, a temperature monitoring component is also disposed on the outer wall of the combustion container 100 to monitor the temperature of the outer wall of the combustion container 100.

[0073] In addition, the outer wall of the combustion container 100 is also covered with a heat-insulating layer 112, and the heating element 410 is arranged between the heat-insulating layer 112 and the outer wall of the combustion container 100. Specifically, the heat-insulating layer 112 includes a stainless steel coating layer covering the outer wall of the combustion container 100 and a heat-insulating filler filled under the stainless steel coating layer, such as heat-insulating cotton, so as to achieve the heat-insulating effect on the combustion container 100.

[0074] The embodiment of the present invention also provides a simulation test method, which can simulate and verify the release of radioactive fission products during the sodium combustion process. The simulation test method in this embodiment can be implemented using the simulation test device in any of the above embodiments. Specifically, the test method in this embodiment includes the following steps.

[0075] Step S20 , heating the sodium delivery tank 210 , the combustion container 100 , and the sodium transmission pipe 500 between the sodium delivery tank 210 and the combustion container 100 .

[0076] Step S30, when the temperatures of the sodium delivery tank 210, the combustion container 100 and the sodium transmission pipe 500 respectively meet the preset conditions, the liquid metallic sodium containing the radioactive fission product simulation substance in the sodium delivery tank 210 is controlled to be transported to the combustion disk 20 of the combustion container 100, and the liquid metallic sodium contacts the air in the combustion disk 20 and starts to burn, forming an aerosol containing the simulation substance.

[0077] Step S40, when the combustion is complete, stop heating and leave the combustion container 100 still to allow the aerosol in the combustion container 100 to settle. When the aerosol is completely settled, take out the sample piece in the combustion container 100 and the sodium oxide generated by the combustion of the liquid metal sodium in the combustion disk 20.

[0078] Step S50, analyzing the release behavior of the simulated substance during the sodium combustion process according to the simulated substance in the aerosol deposited on the sampling sheet and the sodium oxide in the combustion disk 20.

[0079] By adopting the test method in this embodiment, the deposition samples of sodium oxide and aerosol formed after the combustion of sodium containing radioactive fission product simulation material can be collected. Based on these samples, the release, migration and deposition mechanism of radioactive fission products during the sodium combustion process can be analyzed. The method is simple, efficient, safe and reliable.

[0080] Specifically, in step S20, the combustion container 100, the sodium delivery tank 210 and the sodium transmission tube 500 can be heated to make the temperature of the combustion container 100 reach a first preset temperature, and the temperature of the sodium delivery tank 210 and the sodium transmission tube 500 reach a second preset temperature, wherein the first preset temperature is less than the second preset temperature. In this embodiment, before the sodium combustion test begins, the sodium delivery tank 210 and the sodium transmission tube 500 are preheated in advance to make the temperatures of both at a higher temperature than the combustion container 100, which can not only ensure that the liquid metal sodium can be burned after entering the combustion disk 20 of the combustion container 100, but also simulate the actual sodium combustion test working conditions.

[0081] In this embodiment, the first preset temperature may be 150° C. to 200° C., and the second preset temperature may be 400° C. When the sodium delivery tank 210 and the sodium delivery pipe 500 are heated to 400° C., the liquid metal sodium therein also reaches 400° C. At this time, when the high-temperature liquid metal sodium flows into the combustion disk 20 under the air atmosphere, the sodium can be guaranteed to burn. When the combustion container 100 is at 150° C. to 200° C., the high-temperature liquid metal sodium can burn therein, and it does not need to be heated to a high temperature of 400° C.

[0082] In addition, when the combustion container 100, the sodium delivery tank 210 and the sodium transmission pipe 500 are heated by the heating element 410, the heating rate can be controlled within the range of (15-30)°C / h to avoid heating element or equipment loss caused by too fast heating.

[0083] When the temperature of each of the above-mentioned devices meets the preset conditions, the valve provided on the sodium discharge pipe 212 below the sodium delivery tank 210 can be opened, and the liquid metal sodium containing the radioactive fission product simulation substance in the sodium delivery tank 210 is input into the combustion disk 20 of the combustion container 100, and the sodium combustion simulation test is started. Sodium burns in the combustion container 100 under the air atmosphere to form an aerosol of sodium oxide, and the aerosol contains a simulation substance of the radioactive fission product (for example, cesium iodide).

[0084] During the sodium combustion process, the test personnel can observe the sodium combustion through the observation window 111 and record the sodium combustion process using a photographic device. At the same time, the test personnel can record the readings of the temperature monitoring component and the first pressure monitoring component 122 on the combustion container 100, thereby recording the temperature and pressure inside the combustion container 100 during the sodium combustion process.

[0085] When the liquid sodium metal is completely burned, all heating components and power supplies can be turned off to stop heating, and the combustion container 100 can be left standing for a period of time to cool down and allow the aerosol in the combustion container 100 to settle. For example, the combustion container can be left standing for 24 hours to ensure that the combustion container 100 cools to room temperature and the aerosol therein can be completely settled.

[0086] When the aerosol is completely deposited, the first fastener 123 connecting the sealing cover 120 and the main body 110 of the combustion container 100 can be removed. After opening the sealing cover 120, the test personnel can take out the sampling piece on the sampling table 30 through a special sampling hook and store it in a sample bag for subsequent analysis and testing.

[0087] In this embodiment, the sampling pieces placed on the multiple sampling tables 30 can be taken out in sequence, which is convenient for distinguishing the sampling pieces at different positions and avoiding confusion, which is beneficial to the subsequent analysis of the mechanism of aerosol diffusion, migration and deposition. For example, multiple sampling pieces distributed along the axial direction of the combustion container 100 can be taken out in sequence from top to bottom, and then multiple sampling pieces distributed along the circumferential direction of the combustion container 100 can be taken out in a clockwise or counterclockwise direction. In other embodiments, the sampling pieces can also be taken out in sequence in other orders.

[0088] Subsequently, the combustion disk 20 can be taken out to take out the sodium oxide in the combustion disk 20. After the sodium oxide is taken out, it can be placed in a sample storage container and sealed for storage to achieve sampling, testing and analysis of the sodium oxide. The sample storage container can be a stainless steel container, which is provided with a cover body, which can be sealedly connected to the stainless steel container, so that the sodium oxide can be sealed therein.

[0089] In step S50, the aerosol deposited on the sampling sheet and the sodium oxide in the combustion disk 20 can be tested and analyzed. According to data such as the content of simulated substances in aerosols and sodium oxides at different positions, the release pattern of simulated substances during sodium combustion, such as the release amount and release rate of simulated substances, can be analyzed to obtain the release pattern of radioactive fission products during sodium combustion.

[0090] In some embodiments, the test method further includes: step S60, after the sampling piece and the combustion disk 20 are completely taken out, cleaning the combustion container 100. Specifically, after the sampling piece and the combustion disk 20 are completely taken out, the sealing cover 120 can be reinstalled on the main body 110, and the inner wall of the combustion container 100 is cleaned using the cleaning assembly.

[0091] When the combustion container 100 is cleaned for the first time, the water in the water storage tank 320 is first transported to the spray part 310 on the combustion container 100, and the spray part 310 is used to spray clean water radially into the interior of the combustion container 100 to spray and clean the aerosol adhering to the inner wall of the combustion container 100. During cleaning, the simulated substance (cesium iodide) in the aerosol dissolves in water, and the sodium oxide in the aerosol can react with water to form alkali liquid, which can flow from the discharge port 131 at the bottom of the combustion container 100 to the alkali liquid tank 330 below the combustion container 100, and the alkali liquid tank 330 can collect the alkali liquid flushed from the combustion container 100.

[0092] When the combustion container 100 continues to be cleaned, the alkali liquid in the alkali liquid tank 330 can be transported to the spray part 310, and the alkali liquid is sprayed onto the inner wall of the combustion container 100 by the spray part 310. The aerosol adhering to the inner wall can be dissolved in the alkali liquid, and the cleaned alkali liquid flows into the alkali liquid tank 330 from the discharge port 131 at the bottom of the combustion container 100, so that the alkali liquid collected and stored in the alkali liquid tank 330 is used to clean the inner wall of the combustion container 100, thereby realizing the recycling of the alkali liquid.

[0093] In some embodiments, before the liquid metallic sodium containing the simulated substance is transported to the combustion container 100, the process further includes: step S10 of mixing the radioactive fission product simulated substance and the liquid metallic sodium in the sodium transport tank 210 to obtain the liquid metallic sodium containing the simulated substance.

[0094] In step S10, the gas in the sodium delivery tank is first replaced with an inert gas. Specifically, the sodium delivery tank 210 can be evacuated by a vacuum pump 600. When the sodium delivery tank 210 reaches a certain vacuum degree, the inert gas storage tank 700 is used to transport the inert gas into the sodium delivery tank 210. After the sodium delivery tank 210 is filled with inert gas, the vacuum pump 600 and the inert gas storage tank 700 are used to evacuate and fill the sodium delivery tank 210 with inert gas, and the process is repeated for multiple times, so that the gas in the sodium delivery tank 210 is replaced with an inert gas.

[0095] After the gas replacement of the sodium delivery tank 210 is completed, a water-oxygen analyzer is installed at the sampling port of the sodium delivery tank 210, and the water-oxygen analyzer is used to sample and analyze the gas in the sodium delivery tank 210. If the concentrations of water and oxygen in the sodium delivery tank 210 both meet the preset concentrations, liquid metallic sodium can be delivered to the sodium delivery tank 210.

[0096] Further, after the concentrations of water and oxygen in the sodium delivery tank meet the preset concentrations, the sodium delivery tank 210 is heated by a heating element. After the temperature of the sodium delivery tank 210 is greater than the melting point of metallic sodium, liquid metallic sodium is input into the sodium delivery tank 210. The temperature of the sodium delivery tank 210 can be heated to 150° C. to prevent the liquid metallic sodium from solidifying.

[0097] In this embodiment, the pressure of the inert gas in the inert gas storage tank 700 can be used to drive the sodium in the sodium storage tank to be transported to the sodium delivery tank 210. In the process of transporting sodium, the weighing piece below the sodium delivery tank 210 can be used to determine the mass of the liquid metal sodium input into the sodium delivery tank 210 to determine the amount of sodium input into the sodium delivery tank 210. When the amount of sodium input reaches the target value, the valve at the sodium input pipe 213 on the sodium delivery tank 210 is closed to stop transporting sodium into the sodium delivery tank 210. In addition, the liquid level measuring piece 214 on the sodium delivery tank 210 can also be used to measure the liquid level of the liquid metal sodium. When the liquid level measuring piece 214 detects that the liquid level of the liquid metal sodium reaches a threshold value, the sodium is stopped from being transported into the sodium delivery tank 210.

[0098] When the mass of the liquid sodium metal in the sodium delivery tank 210 reaches the target value, the liquid sodium metal is stopped from being delivered, and the sodium delivery tank 210 is cooled to room temperature. Subsequently, a simulated substance of a radioactive fission product (e.g., cesium iodide) can be added to the sodium delivery tank 210.

[0099] When adding the simulated substance, first open the injection port 215 on the top of the sodium tank 210, add the pre-weighed simulated substance into the sodium tank 210, and then close the injection port 215 again. Next, use the inert gas storage tank 700 to add inert gas into the sodium tank 210, so that the sodium tank 210 is under a slight positive pressure of the inert gas, ensuring that the liquid metallic sodium is protected by the inert gas.

[0100] It should be noted that before the delivery port 215 is opened, the sodium delivery tank 210 is in a slightly positive pressure state of inert gas. When the delivery port 215 is opened and the simulated substance is delivered, the amount of air entering the sodium delivery tank 210 is very small and can be ignored. In addition, after the delivery port is closed, the present embodiment also replenishes the sodium delivery tank 210 with inert gas, so as not to affect the protection of the sodium in the sodium delivery tank 210.

[0101] The embodiment of the present invention adopts the above-mentioned simulation test method to simulate and verify the release, migration and deposition process of radioactive fission products in the sodium combustion process, and can obtain basic data on the release of radioactive fission products in sodium during the sodium combustion process. The method is safe, reliable and easy to operate.

[0102] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0103] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A sodium combustion simulation test device for simulating the release of radioactive fission products during sodium combustion, characterized in that: include: A sodium delivery tank, wherein the sodium delivery tank stores liquid metallic sodium containing a simulated substance of radioactive fission products; A combustion container, wherein the combustion container is connected to the sodium delivery tank via a sodium delivery pipe, and the sodium delivery pipe is used to deliver the liquid metal sodium in the sodium delivery tank to the combustion container; wherein, A drainage pipe is provided in the combustion container, and the drainage pipe passes through the side wall of the combustion container and is connected with the sodium transmission pipe; A combustion disk is arranged at the inner center of the combustion container, and the drainage pipe is used to drain the liquid metal sodium transported by the sodium transmission pipe into the combustion disk, so that the liquid metal sodium contacts the air in the combustion disk and burns to generate an aerosol containing the simulated substance; A plurality of sampling tables are fixed on the inner wall of the combustion container, and sampling sheets are placed on the sampling tables to collect the diffused and deposited aerosol; The combustion container comprises a main body and a sealing cover; The sealing cover is detachably connected to the main body; The sealing cover is provided with an exhaust port, and an aerosol filter is installed on the exhaust port, and the aerosol filter is configured to allow air to pass through but not allow the aerosol to pass through; It also includes a plurality of heating elements, which are respectively arranged on the outer walls of the combustion container, the sodium delivery tank, the drainage pipe and the sodium transmission pipe, and are used to heat the combustion container, the sodium delivery tank, the drainage pipe and the sodium transmission pipe.

2. The simulation test device according to claim 1, characterized in that: A support portion is fixed on the inner wall of the combustion container, and the combustion disk is placed on the support portion.

3. The simulation test device according to claim 1, characterized in that: A plurality of the sampling stations are distributed on the inner wall of the combustion container along the axial direction of the combustion container; and / or A plurality of the sampling stations are distributed on the inner wall of the combustion container along the circumferential direction of the combustion container.

4. The simulation test device according to claim 3, characterized in that: The sampling piece is provided with a hook portion, and the hook portion is configured to be hooked by a sampling tool so as to put the sampling piece into or take it out of the combustion container.

5. The simulation test device according to claim 1, characterized in that: The combustion container is provided with an observation window, which is arranged on the side wall of the combustion container, and the observation window and the combustion disk are located at the same height.

6. The simulation test device according to claim 1, characterized in that: The test device also includes a cleaning component, which includes: A spraying member, arranged on the sealing cover of the combustion container and extending into the combustion container, for spraying and cleaning the aerosol adhered to the inner wall of the combustion container; A water storage tank, wherein water is stored in the water storage tank, the spraying element is connected to the water storage tank, and the water in the water storage tank is used to be transported to the spraying element to clean the inner wall of the combustion container; An alkali liquid tank is located below the combustion container. A discharge port is provided at the bottom of the combustion container. The discharge port is connected to the alkali liquid tank. The discharge port is used to discharge the alkali liquid formed after cleaning the inner wall of the combustion container into the alkali liquid tank. The alkali liquid tank is used to store the alkali liquid.

7. The simulation test device according to claim 6, characterized in that: The spraying part is also connected to the alkali liquid tank, and the alkali liquid stored in the alkali liquid tank is used to be transported to the spraying part to clean the inner wall of the combustion container.

8. The simulation test device according to claim 1, characterized in that: A discharge port is arranged at the bottom of the sodium delivery tank, a sodium discharge pipe is arranged at the discharge port, and the sodium discharge pipe is communicated with the sodium transmission pipe.

9. The simulation test device according to claim 8, characterized in that: A weighing piece is arranged below the sodium delivery tank, and the weighing piece is used to weigh the total mass of the sodium delivery tank and the liquid metallic sodium in the sodium delivery tank.

10. The simulation test device according to claim 9, characterized in that: A liquid level measuring component is installed on the top of the sodium delivery tank, and a measuring end of the liquid level measuring component is inserted into the sodium delivery tank to monitor the liquid level of the liquid metallic sodium in the sodium delivery tank.

11. The simulation test device according to claim 8, characterized in that: The top of the sodium delivery tank is provided with a delivery port, and the delivery port is used to deliver the simulated substance into the sodium delivery tank.

12. The simulation test device according to any one of claims 1 to 11, characterized in that: Also includes: A vacuum pump, connected to the sodium delivery tank, for extracting gas from the sodium delivery tank; An inert gas storage tank, in which inert gas is stored, the inert gas storage tank is connected to the sodium delivery tank, and the vacuum pump and the inert gas storage tank are used to replace the gas in the sodium delivery tank with the inert gas.

13. The simulation test device according to claim 12, characterized in that: Also includes: A sodium storage tank stores liquid metallic sodium, and the sodium storage tank is used to transport the liquid metallic sodium to the sodium delivery tank when the interior of the sodium delivery tank is filled with the inert gas.

14. The simulation test device according to claim 1, characterized in that: Also includes: A plurality of temperature monitoring components are respectively arranged on the combustion container, the sodium delivery tank or the sodium transmission pipe, and are used to monitor the temperature of the outer wall of the combustion container, the sodium delivery tank or the sodium transmission pipe.

15. The simulation test device according to claim 14, characterized in that: A measuring end of one of the temperature monitoring components is inserted into the combustion container, and the temperature monitoring component is also used to monitor the temperature inside the combustion container.

16. A simulation test method for simulating and verifying the release of radioactive fission products during sodium combustion, characterized in that: The simulation test method is implemented using the simulation test device according to any one of claims 1 to 15, and the method comprises: Heating the sodium delivery tank, the combustion container and the sodium transmission pipe between the sodium delivery tank and the combustion container; When the temperatures of the sodium delivery tank, the combustion container and the sodium transmission pipe meet the preset conditions, the liquid metal sodium containing the radioactive fission product simulation substance in the sodium delivery tank is controlled to be delivered to the combustion disk of the combustion container, and the liquid metal sodium contacts the air in the combustion disk and starts to burn, forming an aerosol containing the simulation substance; When the combustion is complete, stopping heating and leaving the combustion container still to allow the aerosol in the combustion container to settle; When the aerosol is completely deposited, taking out the sampling piece in the combustion container and the sodium oxide generated by the combustion of the liquid metal sodium in the combustion plate; The release behavior of the simulated substance during the sodium combustion process is analyzed based on the simulated substance and the sodium oxide in the aerosol deposited on the sampling sheet.

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