A device and method for on-site measurement of key parameters of nuclide diffusion behavior

Abstract

The present invention relates to an apparatus for on-site measurement of key parameters of radionuclide diffusion behavior, comprising a main apparatus body comprising a water inlet layer, a sealing layer, a water quality analysis layer, a pressure stabilization layer, a power layer, a diffusion layer, and a water outlet layer, arranged in sequence. The water inlet layer, the water quality analysis layer, the pressure stabilization layer, the power layer, and the diffusion layer are sequentially connected; the diffusion layer is connected to the ground surface; and a radioactive nuclide tracer is disposed within the pressure stabilization layer. The present invention also provides a method for on-site measurement of key parameters of radionuclide diffusion behavior. The apparatus and method for on-site measurement of key parameters of radionuclide diffusion behavior described herein have the advantages of equipment safety, sample stability, and long-term durability, and can provide a large amount of data and technical support for safety assessments of radioactive waste disposal sites.

Description

Technical Field

[0001] The present invention belongs to the research field of radioactive nuclide groundwater environmental migration behavior, and in particular relates to a device and method for on-site measurement of key parameters of nuclide diffusion behavior. Background Art

[0002] Nuclear energy, as a clean energy source, is bound to develop rapidly. It is foreseeable that significant investment will be made in the construction of disposal sites, crucial facilities for handling nuclear waste. Unlike general waste disposal sites, the government explicitly requires that radioactive waste disposal sites conduct research on the diffusion behavior of radionuclides in various engineering and environmental media to obtain key parameters, which are then used to conduct safety assessments of the facilities. Therefore, obtaining accurate radionuclide diffusion behavior parameters is crucial for safety assessments. Compared to other clean energy sources like solar and wind power, one of the major constraints on the development of nuclear energy is the safety of nuclear facilities. This is also a major factor in public fear of nuclear power, and nuclear safety has always been a hot topic for scholars worldwide. Within the entire nuclear power industry, repositories, as the final disposal site for radioactive waste, are critical facilities at the back end of the nuclear energy industry. Their safety has always been a key component of my country's "safe development of nuclear power" requirements. The safety performance of disposal sites represents the safety level of radioactive waste disposal and is a crucial component in addressing public concerns about the safety and reliability of nuclear energy.

[0003] The diffusion and migration behavior of radionuclides within engineered barriers (backfill materials) and natural barriers (surrounding rock) has long been a hot topic for researchers worldwide in the safety performance evaluation of repositories. Currently, the primary methods for studying radionuclides' diffusion and migration are indoor diffusion experiments and field experiments. The latter, as the parameters obtained more closely reflect actual on-site environmental conditions, has long been the primary experimental approach explored by researchers worldwide. Field measurement experiments present three key challenges: ensuring that radionuclides do not leak in the field; establishing a stable hydraulic connection between the interior and exterior of the device; and obtaining real-time samples (or data) during the experiment.

[0004] Since this type of experiment has a high threshold, there is currently no standardized experimental equipment on the market, and the procedures and standards for project experimental operations have not been established. This is very unfavorable for the safety assessment of radioactive waste disposal sites. Therefore, there is an urgent need to form a set of specialized experimental research equipment and operating procedures. Summary of the Invention

[0005] In response to the defects in the prior art, the purpose of the present invention is to provide a device and method for on-site measurement of key parameters of radionuclide diffusion behavior, which can collect key parameters in a standardized manner, have the advantages of equipment safety, sample stability, and long-term durability, and can provide a large amount of data and technical support for the safety assessment of radioactive waste disposal sites.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a device for on-site measurement of key parameters of radionuclide diffusion behavior, which is arranged in a geological borehole and includes: a device body, the device body including a water inlet layer, a sealing layer, a water quality analysis layer, a pressure stabilization layer, a power layer, a diffusion layer and a water outlet layer arranged in sequence, the water inlet layer, the water quality analysis layer, the pressure stabilization layer, the power layer and the diffusion layer are connected in sequence, the diffusion layer is connected to the ground surface, and a radionuclide tracer is arranged in the pressure stabilization layer; wherein the water inlet layer is used to pump groundwater into the water quality analysis layer through the sealing layer, the water quality analysis layer is used to measure the pH-Eh of the groundwater, the pressure stabilization layer is used to stabilize the water pressure between the radionuclide tracer and the groundwater, and the power layer is used to provide power to the groundwater and the radionuclide tracer to transport the groundwater and the radionuclide tracer to the experimental medium in the diffusion layer, and transport the groundwater and the radionuclide tracer that have passed through the experimental medium to the ground surface through the water outlet layer.

[0007] Furthermore, a water inlet peristaltic pump is provided in the water inlet layer to pump groundwater into the water inlet layer through the water inlet peristaltic pump.

[0008] Furthermore, a groundwater pH-Eh detector is provided in the water quality analysis layer.

[0009] Furthermore, a pressure-stabilizing cavity is provided in the pressure-stabilizing layer, and a pressure stabilizer is movably provided in the pressure-stabilizing cavity to separate the pressure-stabilizing cavity into a groundwater cavity and a tracer cavity. The groundwater cavity is respectively connected to the water quality analysis layer and the power layer. A radioactive nuclide tracer is provided in the tracer cavity and is respectively connected to the power layer and the diffusion layer.

[0010] Furthermore, a groundwater peristaltic pump and a tracer peristaltic pump are provided in the power layer. The groundwater peristaltic pump is respectively connected to the groundwater cavity, the water quality analysis layer and the diffusion layer. The tracer peristaltic pump is respectively connected to the tracer cavity and the diffusion layer.

[0011] Furthermore, a raw liquid tank and a liquid collection tank are provided in the diffusion layer. The raw liquid tank is connected to the tracer cavity and the tracer peristaltic pump, and passes through the water outlet layer to form a raw liquid port. The liquid collection tank is connected to the groundwater peristaltic pump, and passes through the water outlet layer to form a liquid collection port. The experimental medium is located between the raw liquid tank and the liquid collection tank.

[0012] Furthermore, the device for on-site measurement of key parameters of radionuclide diffusion behavior also includes a device fixing part and a transmission layer. The device fixing part is located in the geological borehole to fix the device body. The transmission layer is located on the side of the water-yielding layer close to the ground and is connected to the ground.

[0013] Furthermore, the device for on-site measurement of key parameters of nuclide diffusion behavior also includes a sample collection component, which is located on the ground to collect samples output from the device body through the water-yielding layer.

[0014] Furthermore, the raw liquid port and the liquid taking port are both provided with a water outlet peristaltic pump.

[0015] The present invention also provides a method for on-site measurement of key parameters of radionuclide diffusion behavior, comprising the steps of: arranging a sampling borehole in a field site, placing and fixing a device body in the borehole; extracting groundwater to fully saturate the experimental medium, and recording groundwater pH and Eh data; sampling the device body and analyzing the radioactive nuclides; and when the data reaches diffusion equilibrium, closing the device body to complete the experiment.

[0016] The effect of the present invention is that it can form a set of devices and methods for measuring key parameters of nuclide diffusion behavior in field conditions, and is adaptable to the general main geological borehole sizes, thereby having the advantages of equipment safety, sample stability, and long-term durability, and can provide a large amount of data and technical support for the safety assessment of radioactive waste disposal sites. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a device body in a device for on-site measurement of key parameters of nuclide diffusion behavior provided by the present invention;

[0018] Figure 2 Schematic diagram of the positional relationship between the device fixing parts, bed delivery layer and sample collection components.

[0019] Description of reference numerals:

[0020] 1. Water inlet layer; 2. Sealing layer; 3. Water quality analysis layer; 4. Pressure stabilizing layer; 5. Power layer; 6. Diffusion layer; 7. Water outlet layer; 41. Pressure stabilizing cavity; 42. Pressure stabilizer; 411. Groundwater cavity; 412. Tracer cavity; 51. Groundwater peristaltic pump; 52. Tracer peristaltic pump; 61. Raw liquid tank; 62. Liquid collection tank; 611. Raw liquid port; 621. Liquid collection port; 8. Device fixings; 9. Transport layer; 10. Sample collection assembly. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1-2 As shown, the present invention provides a device for on-site measurement of key parameters of radionuclide diffusion behavior, which is arranged in a geological borehole and includes a device body, which includes a water inlet layer 1, a sealing layer 2, a water quality analysis layer 3, a pressure stabilizing layer 4, a power layer 5, a diffusion layer 6 and a water outlet layer 7 arranged in sequence. The water inlet layer 1, the water quality analysis layer 3, the pressure stabilizing layer 4, the power layer 5 and the diffusion layer 6 are connected in sequence, the diffusion layer 6 is connected to the ground surface, and a radioactive nuclide tracer is arranged in the pressure stabilizing layer 4.

[0023] Among them, the water inlet layer 1 is used to pump groundwater and pass through the sealing layer 2 into the water quality analysis layer 3. The water quality analysis layer 3 is used to measure the pH-Eh of the groundwater. The pressure stabilization layer 4 is used to stabilize the water pressure between the radionuclide tracer and the groundwater. The power layer 5 is used to provide power to the groundwater and the radionuclide tracer to transport the groundwater and the radionuclide tracer to the experimental medium in the diffusion layer 6, and transport the groundwater and the radionuclide tracer that have passed through the experimental medium to the surface through the water outlet layer 7.

[0024] It can be understood that the communication among the water inlet layer 1, the water quality analysis layer 3, the power layer 5, and the diffusion layer 6, as well as the communication between the diffusion layer 6 and the ground surface, can all be achieved through pipelines.

[0025] It will be appreciated that the device for in-situ measurement of key parameters of radionuclide diffusion behavior is adapted to the dimensions of a typical geological borehole. In this embodiment, the device body is cylindrical, 11 cm in diameter, and 5 m in length. In other embodiments, the size and shape of the device body may vary depending on the shape of the geological borehole.

[0026] It can be understood that the water inlet layer 1, sealing layer 2, water quality analysis layer 3, voltage stabilizing layer 4, power layer 5, diffusion layer 6 and water outlet layer 7 can be integrally formed or assembled, as long as the sealing between the two adjacent layers is guaranteed after assembly.

[0027] Furthermore, a water inlet peristaltic pump is provided in the water inlet layer 1 so as to pump groundwater into the water inlet layer 1 through the water inlet peristaltic pump.

[0028] It can be understood that the sealing layer 2 has an internal impermeable material, and its main function is to fix the connecting pipe between the water inlet layer 1 and the water quality analysis layer 3 while preventing groundwater from infiltrating into the water quality analysis layer 3 without being filtered through the pipe.

[0029] Furthermore, a groundwater pH-Eh detector is provided in the water quality analysis layer 3 .

[0030] It can be understood that the data detected by the groundwater pH-Eh detector can be uploaded to the ground through a data cable. On the one hand, it can be used to measure the changes in groundwater quality in real time, and on the other hand, it can be used to determine whether groundwater has entered the water quality analysis layer 3.

[0031] Furthermore, a pressure-stabilizing cavity 41 is provided in the pressure-stabilizing layer 4, and a pressure stabilizer 42 is movably provided in the pressure-stabilizing cavity 41 to separate the pressure-stabilizing cavity 41 into a groundwater cavity 411 and a tracer cavity 412. The groundwater cavity 411 is respectively connected to the water quality analysis layer 3 and the power layer 5. A radioactive nuclide tracer is provided in the tracer cavity 412, and is respectively connected to the power layer 5 and the diffusion layer 6.

[0032] It will be appreciated that after groundwater is analyzed by water quality analysis layer 3, it enters groundwater cavity 411. Simultaneously, the power provided by power layer 5 pumps the groundwater in groundwater cavity 411 and the radionuclide tracer in tracer cavity 412 into the experimental medium in diffusion layer 6. During the extraction process by power layer 5, the position of pressurizer 42 within pressure stabilization cavity 41 is adjusted based on pressure changes within groundwater cavity 411 and tracer cavity 412, thereby maintaining constant water pressure.

[0033] It can be understood that the pressure stabilizer 42 is movably arranged in the pressure stabilizing cavity 41. The movement of the pressure stabilizer 42 can be directly achieved through the friction between the pressure stabilizer 42 and the inner wall of the pressure stabilizing cavity 41, thereby adjusting the water pressure. Alternatively, a guide rail can be set in the pressure stabilizing cavity 41 so that the pressure stabilizer 42 can be movable relative to the pressure stabilizing cavity 41 in a direction perpendicular to the ground. It can also be any other method, as long as the purpose of stabilizing the water pressure can be achieved by floating the pressure stabilizer 42 up and down during the process of extracting groundwater and radioactive nuclide tracers from the power layer 5.

[0034] Furthermore, a groundwater peristaltic pump 51 and a tracer peristaltic pump 52 are provided in the power layer 5. The groundwater peristaltic pump 51 is respectively connected to the groundwater cavity 411, the water quality analysis layer 3 and the diffusion layer 6. The tracer peristaltic pump 52 is respectively connected to the tracer cavity 412 and the diffusion layer 6.

[0035] It can be understood that the groundwater peristaltic pump 51 and the tracer peristaltic pump 52 provide power for the flow of groundwater and tracer respectively.

[0036] Furthermore, a raw liquid tank 61 and a liquid collection tank 62 are provided in the diffusion layer 6. The raw liquid tank 61 is connected to the tracer cavity 412 and the tracer peristaltic pump 52, and passes through the water outlet layer 7 to form a raw liquid port 611. The liquid collection tank 62 is connected to the groundwater peristaltic pump 51, and passes through the water outlet layer 7 to form a liquid collection port 621. The experimental medium is located between the raw liquid tank 61 and the liquid collection tank 62.

[0037] It can be understood that the diffusion layer 6 is the main experimental device, wherein the upper part is in contact with the radioactive nuclides (the original liquid tank 61), the lower part is in contact with the groundwater (the liquid sampling tank 62), and the middle part is the experimental medium under study. By real-time analysis of the changes in the content of radioactive nuclides in the groundwater, the diffusion behavior of radioactive nuclides in the experimental medium under the concentration gradient is studied.

[0038] It can be understood that the water outlet layer 7 has the same function as the sealing groove 2 and is built with impermeable material to prevent the radioactive nuclide tracer and groundwater from leaking from positions other than the raw liquid port 611 and the liquid extraction port 621.

[0039] Furthermore, the device for on-site measurement of key parameters of radionuclide diffusion behavior also includes a device fixing part 8 and a transmission layer 9. The device fixing part 8 is located in the geological borehole to fix the device body. The transmission layer 9 is located on the side of the water-yielding layer 7 close to the ground and is connected to the ground.

[0040] Furthermore, the device for on-site measurement of key parameters of nuclide diffusion behavior also includes a sample collection component 10, which is located on the ground to collect samples output from the device body through the water-yielding layer 7.

[0041] In this embodiment, the sample collection assembly 10 is used to collect liquid flowing out of the original liquid port 611 and the liquid extraction port 621 .

[0042] Furthermore, both the original liquid port 611 and the liquid extraction port 621 are provided with a water outlet peristaltic pump to extract the liquid from the original liquid port 611 and the liquid extraction port 621 .

[0043] The present invention also provides a method for on-site measurement of key parameters of nuclide diffusion behavior, comprising the steps of:

[0044] S1, arrange sampling holes in the field, place the device body in the holes and fix it;

[0045] Specifically, a sampling borehole is arranged in the field and drilled according to the groundwater level until the borehole exceeds the groundwater level by about 1-2 meters, ensuring a stable groundwater flow even during the dry season. After drilling is completed, the device is placed in the borehole and secured for subsequent sampling.

[0046] S2, extract groundwater to fully saturate the experimental medium and record the groundwater pH and Eh data;

[0047] Specifically, the groundwater in the sampling borehole is extracted using the water inlet layer in the device body, and the experimental medium in the device body is fully saturated. At the same time, the pH and Eh data of the groundwater are recorded.

[0048] S3, sampling the main body of the device and performing radionuclide analysis;

[0049] Specifically, the peristaltic pump of the water layer is turned on at a fixed experimental node, the radionuclides in the original liquid tank and the liquid extraction tank are analyzed, and the diffusion curve is drawn.

[0050] S4, when the data reaches diffusion equilibrium, the device body is closed and the experiment is completed;

[0051] Specifically, when the experimental data reaches the expected time (after diffusion equilibrium), the entire experimental device is closed, the integrated experimental device is taken out, and the experimental process is completed.

[0052] It can be seen from the above embodiments that the present invention can form a set of devices and methods for measuring key parameters of nuclide diffusion behavior in field conditions, and is adaptable to general major geological borehole sizes, thereby having the advantages of equipment safety, sample stability, and long-term durability, and can provide a large amount of data and technical support for the safety assessment of radioactive waste disposal sites.

[0053] The present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the scope of the technical innovation of the present invention.

Claims

1. A device for on-site measurement of key parameters of nuclide diffusion behavior, arranged in a geological borehole, characterized in that: The device comprises a main body, which includes a water inlet layer, a sealing layer, a water quality analysis layer, a pressure stabilization layer, a power layer, a diffusion layer and a water outlet layer arranged in sequence, wherein the water inlet layer, the water quality analysis layer, the pressure stabilization layer, the power layer and the diffusion layer are connected in sequence, the diffusion layer is connected to the ground surface, and a radioactive nuclide tracer is arranged in the pressure stabilization layer; The water inlet layer is used to pump groundwater into the water quality analysis layer through the sealing layer. The water quality analysis layer is used to measure the pH-Eh of the groundwater. The pressure stabilization layer is used to stabilize the water pressure between the radionuclide tracer and the groundwater. The power layer is used to provide power to the groundwater and the radionuclide tracer to transport the groundwater and the radionuclide tracer to the experimental medium in the diffusion layer, and to transport the groundwater and the radionuclide tracer that have passed through the experimental medium to the surface through the water outlet layer. A pressure stabilizing cavity is provided in the pressure stabilizing layer, and a pressure stabilizer is movably provided in the pressure stabilizing cavity to separate the pressure stabilizing cavity into a groundwater cavity and a tracer cavity. The groundwater cavity is respectively connected to the water quality analysis layer and the power layer. A radioactive nuclide tracer is provided in the tracer cavity and is respectively connected to the power layer and the diffusion layer. A groundwater peristaltic pump and a tracer peristaltic pump are provided in the power layer, the groundwater peristaltic pump is communicated with the groundwater cavity, the water quality analysis layer and the diffusion layer respectively, and the tracer peristaltic pump is communicated with the tracer cavity and the diffusion layer respectively; A raw liquid tank and a liquid collection tank are provided in the diffusion layer. The raw liquid tank is connected to the tracer cavity and the tracer peristaltic pump, and passes through the water outlet layer to form a raw liquid port. The liquid collection tank is connected to the groundwater peristaltic pump, and passes through the water outlet layer to form a liquid collection port. The experimental medium is located between the raw liquid tank and the liquid collection tank.

2. The device for on-site measurement of key parameters of nuclide diffusion behavior according to claim 1, characterized in that: A water inlet peristaltic pump is provided in the water inlet layer so as to pump groundwater in through the water inlet peristaltic pump.

3. The device for on-site measurement of key parameters of nuclide diffusion behavior according to claim 1, characterized in that: The water quality analysis layer is provided with a groundwater pH-Eh detector.

4. The device for on-site measurement of key parameters of nuclide diffusion behavior according to claim 1, characterized in that: The device for on-site measurement of key parameters of nuclide diffusion behavior also includes a device fixing part and a transmission layer. The device fixing part is located in the geological borehole to fix the device body. The transmission layer is located on the side of the water-yielding layer close to the ground and is connected to the ground.

5. The device for on-site measurement of key parameters of nuclide diffusion behavior according to claim 1, characterized in that: The device for on-site measurement of key parameters of nuclide diffusion behavior further comprises a sample collection assembly, which is located on the ground to collect samples output from the device body through the water-yielding layer.

6. The device for on-site measurement of key parameters of nuclide diffusion behavior according to claim 1, characterized in that: The raw liquid port and the liquid taking port are both provided with a water outlet peristaltic pump.

7. A method for on-site measurement of key parameters of nuclide diffusion behavior, characterized in that: Using the device for on-site measurement of key parameters of nuclide diffusion behavior according to any one of claims 1 to 6, the method comprises the steps of: Arrange sampling holes in the field, place the device body in the holes and secure it; Extract groundwater to fully saturate the experimental medium and record groundwater pH and Eh data; Sampling the main body of the device and conducting radionuclide analysis; When the data reaches diffusion equilibrium, the device body is closed and the experiment is completed.

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