A permeability testing device and method

Abstract

The application provides a permeability testing device and a testing method, and relates to the technical field of permeability testing.The device comprises a storage container, a pipe body and a first valve.The storage container contains a trapping liquid.The pipe body penetrates the storage container, and both ends of the pipe body are located outside the storage container.Both ends of the pipe body are sealed, and the pipe body contains a liquid whose permeability needs to be tested.The first valve is arranged on the top of the storage container.The permeability testing device provided by the application can test the permeability of the liquid in the pipeline, and the permeability testing device provided by the application is convenient to use and has low production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of permeability testing, and in particular to a permeability testing device and a testing method. Background Art

[0002] Permeability testing is an important method for evaluating a material's ability to penetrate liquids, and is widely used in fields such as materials science, chemical engineering, and environmental engineering. Permeability is influenced by numerous factors, including the material's microstructure and porosity, as well as the physical and chemical properties of the liquid itself. Accurate permeability measurement is crucial for material selection, environmental monitoring, and product performance evaluation, helping engineers and researchers develop more effective design plans and safety measures.

[0003] However, research and relevant data on the permeability of liquids in pipelines, such as tritiated water, are still scarce, particularly regarding permeability testing of tritiated water. As a unique fluid, the permeability characteristics of tritiated water are of great significance to environmental safety and engineering design. Therefore, effectively measuring the permeability of liquids in pipelines has become a pressing scientific challenge. This is not only crucial for ensuring the integrity and safety of pipeline systems, but also provides new directions and challenges for further research.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0005] In order to solve the above problems, the present invention discloses a permeability testing device and a testing method.

[0006] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by practice of the present disclosure.

[0007] In one aspect, a permeability testing device is provided, comprising:

[0008] A storage container, wherein the storage container is used to hold the captured liquid;

[0009] The tube body passes through the storage container, and both ends of the tube body are located outside the storage container. Both ends of the tube body are sealed, and the tube body contains the liquid to be tested for permeability;

[0010] A first valve is provided on the top of the storage container, and the first valve is used to input the captured liquid;

[0011] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0012] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0013] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0014] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0015] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0016] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0017] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0018] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0019] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0020] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0021] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0022] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0023] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0024] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0025] The pipe body is provided with a pressure gauge at one end outside the storage container, and is provided with a second valve at the other end outside the storage container, the second valve is used to add the liquid with to-be-tested permeability into the pipe body, and is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body;

[0026] As a preferred technical solution, the ratio of the volume of the trapping liquid in the storage container to the volume of the sampling sample is greater than or equal to 80.

[0027] As a preferred technical solution, the first valve is opened for sampling every 10 days, and the radioactivity concentration of the nuclide in the sampling sample is tested to obtain the radioactivity concentration of the nuclide outside the pipe body.

[0028] As a preferred technical solution, a curve of the permeation flux changing with time is drawn, and when the permeation curve observes that the permeation reaches a steady state, that is, when the radioactivity does not change with time, the test is ended.

[0029] As a preferred technical solution, when the radioactivity does not change with time, the test is ended, the tested pipe body is taken out, the pipe body is crushed and sampled, and then the tritium activity concentration in the pipe body is measured.

[0030] The present application has the beneficial technical effects that:

[0031] 1. The permeation rate testing device of the present application can test the permeation rate of the liquid in the pipeline, and the permeation rate testing device provided by the present application is convenient to use and has low production cost.

[0032] 2. The two ends of the pipe body are located outside the storage container, which can prevent the liquid in the pipe body from leaking into the storage container and affecting the test results.

[0033] 3. The support part is arranged to facilitate the addition of liquid into the pipe body.

[0034] 4. The inner cavity of the pipe body is pressurized, so that the permeation rate of the liquid in the pipe body can be tested in a short period of time.

[0035] 5. The storage container is added with the trapping liquid meeting at least 80 times of sampling, so as to ensure that the test can collect enough samples and ensure the accuracy of the test results.

[0036] 6. The present application provides a test method for testing the tritiated water permeation rate of pipe materials, which is simple to test and has low production cost of the test device.

[0037] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0038] The drawings incorporated into the specification and forming a part thereof show embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0039] Figure 1 Fig. 1 shows a structural schematic diagram of a permeability testing device in an embodiment of the present disclosure;

[0040] Figure 2 Fig. 2 shows a structural schematic diagram of a permeability testing device in another embodiment of the present disclosure;

[0041] Figure 3 Fig. 3 shows a structural schematic diagram of a permeability testing device in still another embodiment of the present disclosure;

[0042] Figure 4 Fig. 4 shows a structural schematic diagram of a permeability testing device in yet another embodiment of the present disclosure;

[0043] Figure 5 Fig. 5 shows a permeability testing method in an embodiment of the present disclosure;

[0044] Figure 6 Fig. 6 shows a partial cross-sectional schematic diagram of a tube in an embodiment of the present disclosure.

[0045] Legend of reference numerals: storage container 1; tube 2; first valve 3; support portion 4; voltmeter 5; second valve 6. DETAILED DESCRIPTION

[0046] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations can be implemented in any

[0047] In addition, the drawings are to be considered in all respects as illustrative and not restrictive; identical reference numerals have been used, where possible, to denote identical or similar features, and thus repetitive descriptions thereon will be omitted. Some of the block components shown in the drawings can be functional blocks that do not necessarily have to have physical or logical boundaries in the real world. These functional blocks can be implemented in software, or in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0048] It should be understood that the various steps in the method implementations of the present disclosure can be performed in different order, and / or in parallel. In addition, the method implementations can include additional steps and / or omit performing the steps shown. The scope of the present disclosure is not limited in this respect.

[0049] It should be noted that the terms "first", "second", and the like in the present disclosure are only used to distinguish different devices, modules or units, and do not limit the order or interdependence of the functions performed by these devices, modules or units.

[0050] It should be noted that the modification of "one" or "multiple" in the present disclosure is illustrative but not restrictive, and those skilled in the art should understand that unless otherwise explicitly indicated in the context, it should be understood as "one or more".

[0051] Figure 1 The structure of the permeability testing device in an embodiment of the present disclosure is shown in a schematic diagram as shown in Figure 1 As shown, a permeability testing device can include: a storage container 1, the storage container 1 containing a trapping liquid; a pipe body 2, the pipe body 2 penetrating the storage container 1, and both ends of the pipe body 2 being located outside the storage container 1, both ends of the pipe body 2 being sealed, the pipe body 2 containing a liquid to be tested for permeability; and a first valve 3, the first valve 3 being arranged at the top of the storage container 1.

[0052] In an embodiment of the present disclosure, the trapping liquid is a trapping liquid used to test the permeability of the liquid in the pipe body 2, and the liquid in the pipe body 2 can diffuse into the trapping liquid through the pipe body 2. The present disclosure does not limit the specific type of trapping liquid. For example, the trapping liquid is ultrapure water. For another example, the trapping liquid is multiple distilled water. For example, the trapping liquid is twice distilled water or thrice distilled water. It should be noted that the trapping liquid is added to the storage container 1 through the first valve 3.

[0053] In an embodiment of the present disclosure, the liquid to be tested for permeability can be a solution of inorganic compounds carrying radionuclides. For example, the liquid to be tested for permeability can be tritiated water. For example, the liquid to be tested for permeability is a salt-containing tritiated water sample.

[0054] In an embodiment of the present disclosure, the pipe body 2 is sealingly connected with the penetration part of the storage container 1, and the present disclosure does not limit how to achieve the sealing. For example, the sealing is achieved by an O-ring. For another example, the pipe body 2 and the storage container 1 are integrally injection molded / cast formed. For another example, the pipe body 2 and the storage container 1 are threadedly detachably connected.

[0055] In an embodiment of the present disclosure, the shape of the pipe body 2 and the storage container 1 is not limited. For example, the cross section of the pipe body 2 can be circular, oval or rectangular. The storage container 1 can be cuboid, spherical, cubic or circular truncated cone. For example, the pipe body 2 is cylindrical and the storage container 1 is cuboid.

[0056] In the embodiments of the present disclosure, the way of how to seal the two ends of the pipe body 2 is not limited. For example, when the material of the pipe body 2 is thermoplastic plastic, the two ends of the pipe body 2 are blocked by first plugs, and the first plugs are connected to the two ends of the pipe body 2 by heat melting, wherein the material of the first plug is the same as that of the pipe body 2. It should be noted that when the material of the first plug is the same as that of the pipe body 2, it is beneficial to connect the first plug to the two ends of the pipe body 2 by heat melting, and each end of the pipe body 2 has a first plug. The material of the pipe body 2 can be one of polypropylene, polyvinyl chloride and polyethylene. For example, the material of the pipe body 2 can be polyethylene.

[0057] For another example, when the pipe body 2 is a metal material, the two ends of the pipe body 2 are blocked by second plugs, and the second plugs are threadedly connected to the two ends of the pipe body 2, and the material of the second plug is the same as that of the pipe body 2. It should be noted that when the material of the second plug is the same as that of the pipe body 2, it is beneficial to connect the second plug to the two ends of the pipe body 2 by thread sealing. Each end of the pipe body 2 has a second plug. The material of the pipe body 2 can be one of stainless steel, carbon steel, alloy steel, titanium alloy, aluminum alloy and copper alloy. For example, the material of the pipe body 2 is stainless steel.

[0058] In the embodiments of the present disclosure, the two ends of the pipe body 2 are located outside the storage container 1, which can prevent the liquid in the pipe body 2 from leaking into the storage container 1, thereby affecting the test result.

[0059] In the embodiments of the present disclosure, the way of how to add the liquid into the pipe body 2 is not limited. For example, when the pipe body 2 is detachably connected to the storage container 1, one end of the pipe body 2 is sealed first, the liquid is added into the pipe body 2, and then the other end of the pipe body 2 is sealed. After that, the pipe body 2 containing the liquid to be tested for permeability is installed on the storage container 1. For another example, when the pipe body 2 is fixedly connected to the storage container 1, one end of the pipe body 2 is sealed first, and then the liquid is added into the pipe body 2, and then the other end of the pipe body 2 is sealed. In order to facilitate the addition of the liquid into the pipe body 2, the pipe body 2 can be placed vertically first. For example, as shown in Figure 2 shown, one side of the storage container 1 is provided with a support part 4, and when the storage container 1 is rotated to the position that the support part 4 is below the storage container 1, the pipe body 2 is in a vertical state. The support part 4 is used to support the storage container 1, so that the pipe body 2 is in a vertical state, and the liquid can be easily added into the pipe body 2. The specific structure of the support part 4 is not limited in the embodiments of the present disclosure. For example, the support part 4 includes a plurality of support rods. The height of the support part 4 is greater than the length of the extension part of the pipe body 2 extending out of the storage container 1, and when the storage container is rotated to the position that the support part 4 is below the storage container 1, the pipe body 2 is in a vertical state. For another example, the support part 4 is a retractable support frame, which is elongated when in use and retracted when no liquid is added.

[0060] The permeability testing device provided by the present disclosure can test the permeability of the liquid in the pipeline, and the permeability testing device provided by the present disclosure is convenient to use and has low production cost.

[0061] The permeability testing device described above can test the permeability of the liquid (such as tritiated water) to be tested in the pipe body under normal pressure. When the pipe body is made of hard high-density material, a large amount of data may not be obtained in a short period of time. If the measurement results are all below the detection limit (about 1 Bq / L (Becquerel per liter)), the specific permeability value cannot be obtained, and further testing is performed by increasing the pressure using the permeability testing device described below. If the permeability value can be obtained, the testing experiment of different specifications of pipe materials is continued.

[0062] Figure 3 The structure of the permeability testing device in another embodiment of the present disclosure is shown in the structural schematic diagram as shown in Figure 3 The permeability testing device can include a storage container 1 containing a trapping liquid, a pipe body 2 penetrating the storage container 1, both ends of the pipe body 2 being located outside the storage container 1, both ends of the pipe body 2 being sealed, and the pipe body 2 containing a liquid to be tested for permeability. A first valve 3 is arranged at the top of the storage container 1. A pressure gauge 5 is arranged at one end of the pipe body 2 outside the storage container 1, and a second valve 6 is arranged at the other end of the pipe body 2 outside the storage container 1. The pressure gauge 5 and the second valve 6 are both located outside the storage container 1. The second valve 6 is used to add the liquid to be tested for permeability into the pipe body 2, and the second valve 6 is also used to be connected with an external pressurizing device to pressurize the internal cavity of the pipe body 2, so that the permeability of the liquid in the pipe body 2 can be tested in a short period of time. For example, the liquid to be tested for permeability (such as tritiated water standard solution) is added into the pipe body 2 through the second valve 6, and then nitrogen is supplemented into the pipe body 2 through the second valve 6 to a pressure of 0.5 MPa (megapascal), and then the second valve 6 is closed.

[0063] In an embodiment of the present disclosure, the trapping liquid is a trapping liquid used for testing the permeability of the liquid in the pipe body 2, and the liquid in the pipe body 2 can diffuse into the trapping liquid through the pipe body 2. The present disclosure does not limit the specific type of the trapping liquid. For example, the trapping liquid is ultrapure water. For another example, the trapping liquid is multiple distilled water. For example, the trapping liquid is twice distilled water or thrice distilled water. It should be noted that the trapping liquid is added into the storage container 1 through the first valve 3. The pipe body 2 located in the storage container 1 is immersed in the trapping liquid.

[0064] In an embodiment of the present disclosure, the liquid to be tested for permeability can be a solution of an inorganic compound carrying a radionuclide. For example, the liquid to be tested for permeability is tritiated water. For example, the liquid to be tested for permeability is a sample of salt-containing tritiated water.

[0065] In the embodiments of the present disclosure, the pipe body 2 is sealingly connected with the storage container 1 at the through part. The sealing manner is not limited in the embodiments of the present disclosure. For example, the sealing is achieved by an O-shaped sealing ring. For another example, the pipe body 2 and the storage container 1 are integrally injection molded or cast formed. For another example, the pipe body 2 and the storage container 1 are threadedly detachably connected.

[0066] In the embodiments of the present disclosure, the shape of the pipe body 2 and the storage container 1 is not limited. For example, the cross section of the pipe body 2 can be circular, oval or rectangular. The storage container 1 can be cuboid, spherical, cubic or circular truncated cone shaped.

[0067] The installation positions of the voltmeter and the second valve are described below.

[0068] As a preferred technical solution, as shown in Figure 3 , the voltmeter 5 can be installed at one end of the pipe body 2, and the second valve 6 can be installed at the other end of the pipe body 2.

[0069] In another embodiment, as shown in Figure 4 , the voltmeter 5 and the second valve 6 are installed on the pipe body 2. Both the voltmeter 5 and the second valve 6 are sealingly connected with the pipe body 2. When the voltmeter 5 and the second valve 6 are installed on the pipe body 2, the sealing manner of the two ends of the pipe body 2 is not limited in the embodiments of the present disclosure. For example, when the material of the pipe body 2 is thermoplastic plastic, the two ends of the pipe body 2 are blocked by first plugs, and the first plugs are heat-fusedly connected to the two ends of the pipe body 2, wherein the material of the first plug is the same as that of the pipe body 2. It should be noted that when the material of the first plug is the same as that of the pipe body 2, it is beneficial to heat-fuse the first plug to the two ends of the pipe body 2, and each end of the pipe body 2 has a first plug. The material of the pipe body 2 can be one of polypropylene, polyvinyl chloride and polyethylene. For example, the material of the pipe body 2 can be polyethylene. For another example, when the pipe body 2 is a metal material, the two ends of the pipe body 2 are blocked by second plugs, the second plugs are threadedly connected with the pipe body 2, and the material of the second plug is the same as that of the pipe body 2. It should be noted that when the material of the second plug is the same as that of the pipe body 2, it is beneficial to threadedly sealingly connect the second plug to the two ends of the pipe body 2. Each end of the pipe body 2 has a second plug. The material of the pipe body 2 can be one of stainless steel, carbon steel, alloy steel, titanium alloy, aluminum alloy and copper alloy. For example, the material of the pipe body 2 is stainless steel.

[0070] In the embodiments of the present disclosure, the pipe body is pressurized by the second valve, so that the permeability of the liquid in the pipe body can be tested in a short period of time, and the test efficiency is improved.

[0071] Based on the same inventive concept, the disclosure also provides a permeability testing method, as described in the following embodiment. Since the principle of solving problems of the method embodiment is similar to that of the above-mentioned device embodiment, the implementation of the method embodiment can be referred to the implementation of the above-mentioned device embodiment, and the repeated parts will not be described here.

[0072] Figure 5 A permeability testing method is shown in the embodiment of the disclosure, as Figure 5 As shown, the permeability testing device applied in the above-mentioned embodiment, the method can include the following S501 to S505.

[0073] S501, adding a liquid with a permeability to be tested into the pipe body, and sealing the pipe body.

[0074] In the embodiment of the disclosure, the activity of the nuclide contained in the liquid with a permeability to be tested is a known amount. As to how to seal the pipe body, it has been described in the above-mentioned embodiment, and will not be described here.

[0075] As to how to add the liquid with a permeability to be tested into the pipe body, it can be determined according to whether it is a normal pressure test or a pressurized test.

[0076] As a preferred technical solution, the permeability test is a normal pressure test, adding the liquid with a permeability to be tested into the pipe body, and sealing the pipe body, can include any one of the following: adding the liquid with a permeability to be tested into the pipe body through one port of the pipe body, and sealing the pipe body; adding the liquid with a permeability to be tested into the pipe body through the second valve, and closing the second valve to seal the pipe body.

[0077] In another embodiment, the permeability test is a pressurized test, adding the liquid with a permeability to be tested into the pipe body, and sealing the pipe body, can include: adding the liquid with a permeability to be tested into the pipe body through the second valve, and pressurizing the pipe body, and closing the second valve to seal the pipe body after pressurizing. For example, filling the pipe body with tritiated water standard solution, and closing the second valve after supplementing nitrogen to a pressure of 0.5 MPa.

[0078] S502, adding a trapping liquid into the storage container, and closing the first valve.

[0079] In the embodiment of the disclosure, the amount of the trapping liquid added can be determined according to the testing requirements. For example, the ratio of the volume of the trapping liquid in the storage container to the volume of the sampling sample is greater than or equal to 80. For example, the ratio of the volume of the trapping liquid in the storage container to the volume of the sampling sample is any value in 80-200. The embodiment of the disclosure adds a trapping liquid that meets at least 80 times of sampling into the storage container, so as to ensure that the test can collect enough samples, and ensure the accuracy of the test results.

[0080] S503, opening the first valve every first time length to sample and testing the radioactivity concentration of the nuclide in the sampling sample to obtain the radioactivity concentration of the nuclide outside the tube body.

[0081] In the embodiments of the present disclosure, the size of the first time length is determined according to the properties of the liquid to be tested and the material of the tube body. For the liquid with large permeability and the tube body with small density, the value of the first time length can be determined as a small value. For the liquid with small permeability and the tube body with large density, the value of the first time length can be determined as a large value. For example, the value of the first time length can be in the range of 8-30 days, and for the liquid with large permeability and the tube body with small density, the value of the first time length can be determined as 8 days. For the liquid with small permeability and the tube body with large density, the value of the first time length can be determined as 30 days.

[0082] For example, when the liquid is standard tritiated water and the material of the tube body is stainless steel, the first time length is 10 days.

[0083] In the embodiments of the present disclosure, the device used to test the radioactivity concentration of the nuclide in the sampling sample is not limited. For example, the liquid scintillation spectrometer can be used to test the radioactivity concentration of the nuclide in the sampling sample.

[0084] S504, determining the radioactivity of the nuclide according to the radioactivity concentration of the nuclide outside the tube body.

[0085] In the embodiments of the present disclosure, the radioactivity of the nuclide is the activity of the nuclide that permeates the tube wall in t time, wherein t is the time from the start of the test to the sampling test. The radioactivity of the nuclide can be calculated according to the radioactivity concentration of the nuclide outside the tube body and the volume of the remaining trapping liquid in the storage container.

[0086] S505, obtaining the diffusion coefficient of the tube body to the liquid in the case that the radioactivity of the nuclide does not change with time.

[0087] In the embodiments of the present disclosure, when the cross section of the tube body is circular, the diffusion coefficient of the sampling sample can be solved by the Fick's law expression in the cylindrical coordinate system.

[0088] It should be noted that, in the whole process of the nuclide in the liquid permeating the material, if the time required by the surface process is much smaller than the time of the nuclide diffusing in the material matrix, the permeation rate of the nuclide is mainly determined by the diffusion process, that is, the diffusion behavior of the nuclide becomes the control factor of the permeation speed of the nuclide, and the diffusion coefficient obtained by the test can be equivalent to the permeability of the liquid.

[0089] It should be noted that, in the test of each tube body, a separate permeability test device is used to avoid cross contamination between the tube bodies.

[0090] The disclosed embodiments use a normal-pressure permeability testing device to test the permeability of a tube body on a solution containing radionuclides. This test can assess the tube body material's ability to protect against radionuclides, ensuring its safe use in nuclear energy or radioactive waste disposal. This helps monitor and analyze potential radioactive contamination, supporting environmental protection and safety management. The normal-pressure permeability testing device has a simple structure and low production cost.

[0091] The disclosed embodiment uses a pressurized permeability testing device to perform a permeability test on the solution contained in the tube body. The pressurized environment can more effectively simulate actual use conditions, obtain more realistic permeability data, and ensure that the tube body can still effectively isolate radioactive nuclides under high pressure conditions to ensure safety. It can also more comprehensively evaluate the performance of various materials under different pressures, providing a basis for selecting suitable materials. In addition, by applying pressure, the penetration rate of the solution through the tube body can be accelerated, thereby shortening the experimental time. The pressurized permeability testing device has a relatively simple structure and low production cost.

[0092] The following description will be made by taking tritiated water as an example of the liquid to be tested for permeability.

[0093] Related technologies exist for testing the permeability of tritium gas and tritiated water on flat sheet materials (tritiated water is rarely tested), but there are no methods for testing the permeability of tritiated water on cylindrical tubing (tubes). Tritiated water is an inorganic compound composed of one hydrogen, one tritium, and one oxygen, with the chemical formula HTO. When tritiated water is present in tubing, the permeability effect of tritium needs to be considered.

[0094] Parameters used to quantitatively evaluate tritium's diffusion and permeation behavior in solid materials include permeability, diffusion coefficient, and solubility coefficient. If the surface process of tritium penetration through a material takes significantly less time than the time it takes for tritium to diffuse within the matrix, the tritium permeation rate is primarily determined by the diffusion process. In other words, tritium's diffusion behavior becomes the controlling factor in tritium permeation speed, and the diffusion coefficient obtained from the test can be compared to the permeability of the liquid.

[0095] There is very little research and data on the permeability of tritiated water in pipes. Therefore, in experimental work, the diffusion and permeation parameters (permeability) of tritium in the material are often measured experimentally according to the task requirements.

[0096] Normal pressure test is as follows: Figure 1 As shown, a tube 2 is filled with a tritiated water standard solution (the liquid whose permeability is to be tested) of known activity, sealed at both ends, and secured in a storage container 1. Storage container 1 contains double-distilled water (the capture solution), allowing the tube 2 to be completely submerged. Double-distilled water is periodically drawn and the tritium activity concentration in the double-distilled water is measured. The tritium activity is determined based on the tritium activity concentration in the double-distilled water. Assuming the tritium activity does not change over time, the diffusion coefficient of the tube 2 for the tritiated water standard solution is calculated.

[0097] The experiment was carried out using the pipe body 2 at room temperature and normal pressure in the laboratory. The water in the storage container 1 at different times was collected, and the activity concentration of tritium therein was determined using a low-level liquid scintillation spectrometer. The design information of the pipe body 2 tritiated water permeation experiment device is as follows:

[0098] (1) Basic function: Fill the pipe body 2 with tritiated water standard solution, and seal both ends of the pipe body 2. Open the valve to fill the storage container 1 with a quantitative trapping liquid, and close the first valve 3. After standing for a predetermined time (first time length), open the first valve, take a quantitative sample for measurement. After sampling, close the first valve and stand.

[0099] (2) Storage container 1 sealing: In order to avoid interference and pollution from the external environment, the storage container 1 adopts a fully sealed structure. In order to realize the need for regular sampling monitoring, the upper end of the storage container 1 is connected with a switchable first valve, which minimizes the contact area between the substances in the storage container 1 and the outside during sampling under the conditions of sampling and sampling.

[0100] (3) Pipe body sealing: After the pipe body 2 is sealed at both ends, it passes through the storage container 1, so that the sealed port outside is outside the storage container 1, avoiding the problem of misjudgment caused by possible leakage of the port. When the pipe body 2 is a polyethylene pipe body, the same material plug is used to close the two ends of the polyethylene pipe body by hot melt welding. When the pipe body 2 is a stainless steel pipe body, the same material plug is used to screw close the two ends of the stainless steel pipe body.

[0101] (4) Prevent cross contamination: ① Each pipe body 2 uses a set of pipe body tritiated water permeation experiment device (permeation rate test device) to avoid cross contamination between pipe bodies 2. ② The pipe body tritiated water permeation experiment device is sealed with a first valve, and the first valve is opened for about 2 minutes each time, which maximizes the prevention of excessive contact with the outside environment. ③ The pipe body 2 tritiated water permeation experiment device placed in the same place is placed with an open water sample as an environmental blank, and the environmental water tritium is monitored regularly to prevent external pollution.

[0102] The pressure test is as follows: a stainless steel cuboid box (referred to as storage container 1) sealed with a first valve 3 is used as a storage container, and symmetrically punched below to embed a test pipe body 2, which contains a tritiated water standard solution with a known tritium activity (liquid to be tested for permeation rate). The pipe body 2 is sealed and connected between the storage container 1, one end of the pipe body 2 is connected with a pressure gauge 5, and the other end is equipped with a pressure or liquid valve (second valve 6). The storage container 1 has a first valve 3 for water injection and water taking. The pipe body 2 tritiated water permeation rate test device is shown in Figure 3 .

[0103] The pipe body 2 tritium water permeability test device has the basic function of testing the tritium permeability from the liquid in the pipe body 2 to the outside of the pipe body 2. The pipe body 2 is filled with tritiated water standard solution, and the second valve 6 is closed after the nitrogen gas is supplemented to a pressure of 0.5 MPa. The first valve 3 is opened, the storage container 1 is filled with a quantitative trapping liquid, and the first valve 3 is closed. After standing for a predetermined time, the first valve 3 is opened, and the sample is prepared for measurement. After sampling, the first valve 3 is closed and stands. The trapping liquid is taken periodically and continuously, and the tritium activity concentration in the trapping liquid is measured. The tritium activity is determined according to the tritium activity concentration in the trapping liquid, and the diffusion coefficient of the pipe body to the tritiated water standard solution is obtained when the tritium activity does not change with time.

[0104] In order to avoid interference and pollution from the external environment, the storage container 1 adopts a fully sealed structure. In order to realize the need of periodic sampling monitoring, the upper end of the storage container 1 is connected with a switchable first valve, which can minimize the contact area between the substances in the storage container 1 and the outside during sampling under the conditions of sample addition and sampling.

[0105] The sealing of the pipe body 2 is ensured by the device design and connection process of the present disclosure. The two ends of the pipe body 2 are composed of the second valve 6 and the pressure gauge 4, and the pipe body 2 passes through the storage container 1, so that the sealed port on the outside is outside the storage container 1, avoiding the problem of false judgment caused by possible leakage of the port. When the pipe body 2 is a polyethylene pipe body, the same material plug is used at both ends of the polyethylene pipe body and is closed by heat fusion welding. When the pipe body 2 is a stainless steel pipe body, the same material plug is used at both ends of the stainless steel pipe body and is closed by screwing.

[0106] In order to effectively prevent cross contamination that may occur during testing, various methods such as independent devices, standardized operations and blank monitoring are used to avoid cross contamination. ① Each pipe body 2 uses a set of permeability test device to avoid cross contamination between pipe bodies 2. ② The permeability test device is sealed by the first valve, and the valve is opened for about 2 minutes each time, which maximizes the avoidance of excessive contact with the outside world. ③ The permeability test devices placed in the same place are placed with open water samples as environmental blanks, and the environmental water tritium is monitored regularly to prevent external pollution.

[0107] For example, the permeability test device of the present disclosure is used to test the permeability of liquid in the pipe body, and the permeability test method comprises the following steps A1 to A5.

[0108] Step A1, sample sealing: tritium labeled water sample with known activity is added to the pipe body 2. The second valve 6 is closed. It should be noted that when the pipe body 2 is a polyethylene pipe body, the same material is used at both ends of the polyethylene pipe body and the second valve 6 and the pressure gauge 5 are closed by heat fusion welding. When the pipe body 2 is a stainless steel pipe body, the same material is used at both ends of the stainless steel pipe body and the second valve 6 and the pressure gauge 5 are connected by screwing.

[0109] Step A2, water addition: open the first valve 3 at the top of the storage container 1, add a certain amount of double-distilled water into the storage container 1, and close the first valve 3. The amount of water added should be enough to test 80 sampling samples.

[0110] Step A3, regular testing: regularly take water samples, and then use a liquid scintillation spectrometer to measure the tritium activity concentration in the water. The sampling test frequency is initially set to be tested once every 10 days or so.

[0111] Step A4, curve drawing: for each test scheme, calculate the permeation flux of the pipe body 2 to the tritiated water, that is, test the radioactivity of tritium in the sampling sample. Draw a curve of the permeation flux over time. When the permeation curve observes that the permeation reaches a steady state, that is, when the radioactivity does not change over time, the test is completed.

[0112] Step A5, pipe body 2 tritium concentration test verification: taking a test scheme as an example, when the tritium permeation reaches a steady state, the tested pipe body 2 is taken out, crushed, and sampled, and then the tritium activity concentration in the pipe body 2 is measured.

[0113] It should be noted that based on the permeation rate testing device of the present disclosure, the tritium activity concentration outside the pipe body 2 after a certain time can be obtained. Under the initial condition, the tritium activity concentration inside the pipe body 2 is 4-5 orders of magnitude higher than that outside the pipe body 2. Assuming that the exuded tritium is mainly in the form of a steady-state flow diffusion process, that is, the motive force of tritium permeation is the concentration gradient caused by the uneven distribution of tritium in the material, then by solving the steady-state diffusion equation of the cylindrical pipe and substituting the experimental test data, the diffusion coefficient of the pipe body 2 to the tritiated water can be obtained. The diffusion equation at steady state is shown in the following formula 1.

[0114]

[0115] Wherein, D—diffusion coefficient, unit: cm2 / s; m—tritium activity exuded from the pipe wall within t time, unit: Bq; t—time from the start of the test to the water measurement, unit: s; r1—inner radius of the pipe body, unit: mm; r2—outer radius of the pipe body, unit: mm; L—length of the pipe body (length located in the permeation box), unit: mm; C1—tritium activity concentration inside the pipe body, unit: Bq / L. C2—tritium activity concentration outside the pipe body, unit: Bq / L.

[0116] According to the above formula 1 to solve the diffusion coefficient, the equation of the diffusion coefficient is shown in the following formula 2.

[0117]

[0118] Wherein, D—diffusion coefficient, unit is cm2 / s; m—tritium activity permeating the pipe wall in t time, unit is Bq; t—time from the beginning of the test to the measurement of water, unit is s; r1—inner radius of the pipe, unit is mm; r2—outer radius of the pipe, unit is mm; L—length of the pipe (length in the storage container), unit is mm; C1—tritium activity concentration inside the pipe, unit is Bq / L. C2—tritium activity concentration outside the pipe, unit is Bq / L.

[0119] It should be noted that the length indicated by r1 and r2 is as shown in Figure 6 C1 is the tritium activity concentration inside the pipe, C1, r1 and r2 are all known quantities, and C2 is the tritium activity concentration in the sampling sample measured by a liquid scintillation spectrometer. According to C2 and the volume of water in the storage container 1, m can be calculated, that is, m is the product of C2 and the volume of water in the storage container 1.

[0120] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A permeability testing device, characterized in that: include: a storage container, wherein the storage container is used to hold the captured liquid; a tube body, the tube body passing through the storage container, with both ends of the tube body located outside the storage container, the ends of the tube body being sealed, and the tube body containing a liquid whose permeability is to be tested; A first valve is provided on the top of the storage container, and the first valve is used to input the captured liquid; A pressure gauge is installed at one end of the tube body located outside the storage container, and a second valve is installed at the other end of the tube body located outside the storage container. The second valve is used to add the liquid to be tested for permeability into the tube body, and the second valve is also used to connect to an external pressurizing device so that the pressurizing device pressurizes the inner cavity of the tube body; Both ends of the tube body are provided with plugging heads.

2. A permeability testing device according to claim 1, characterized in that: A supporting portion is provided on the side surface of the storage container, and the supporting portion is distributed at the four corners of the side surface.

3. A permeability testing device according to claim 2, characterized in that: The height of the support portion is greater than the length of the extension portion of the tube extending from the storage container. When the storage container is rotated until the support portion is located below the storage container, the tube body is in a vertical state.

4. A permeability testing device according to claim 1, characterized in that: The liquid to be tested for permeability is tritiated water, and the capture liquid is ultrapure water.

5. A permeability testing method, characterized in that: Applied to the permeability testing device according to any one of claims 1 to 4, the method comprises: Adding a liquid whose permeability is to be tested into the tube body and sealing the tube body; Adding the capture liquid to the storage container and closing the first valve; opening the first valve at first time intervals to take samples, and testing the radioactivity concentration of the nuclides in the sampled samples to obtain the radioactivity concentration of the nuclides outside the tube body; determining the radioactivity of the nuclide based on the radioactivity concentration of the nuclide outside the tube; Under the condition that the radioactivity of the nuclide does not change with time, the diffusion coefficient of the tube body to the liquid is obtained.

6. A permeability testing method according to claim 5, characterized in that: The step of adding the liquid to be tested for permeability into the tube body and sealing the tube body comprises any one of the following: Adding a liquid whose permeability is to be tested into the tube body through a port of the tube body, and sealing the tube body; Adding a liquid whose permeability is to be tested into the tube body through a second valve, and closing the second valve to seal the tube body; The liquid whose permeability is to be tested is added into the tube body through the second valve, and the tube body is pressurized. After pressurization, the second valve is closed to seal the tube body.

7. A permeability testing method according to claim 6, characterized in that: The ratio of the volume of the capture liquid in the storage container to the volume of the sample is greater than or equal to 80.

8. A permeability testing method according to claim 5, characterized in that: The first valve is opened every 10 days to take samples, and the radioactivity concentration of the nuclides in the sampled samples is tested to obtain the radioactivity concentration of the nuclides outside the tube body.

9. A permeability testing method according to claim 8, characterized in that: The permeation flux is plotted as a function of time. The test is terminated when the permeation curve observes a steady state, that is, when the radioactivity does not change with time.

10. A permeability testing method according to claim 9, characterized in that: When the radioactivity does not change with time, the test is completed, the tube body to be tested is taken out, the tube body is crushed, a sample is prepared, and the tritium activity concentration in the tube body is measured.

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