Device and method for measuring aerosol release share and particle size distribution under damage of lead-bismuth fuel

Abstract

The invention discloses a device and a method for measuring aerosol release share and particle size distribution under damage of lead-bismuth fuel. The device comprises a high-pressure gas tank, an aerosol weighing device, a simulation fuel rod, a crevasse sealing device, a collecting device, a wet particle size analyzer, a pipeline valve and a measuring instrument, the high-pressure gas tank is used for providing gas required by the whole device, the aerosol weighing device is used for weighing aerosol powder used in the fuel rod in an initial state, and the simulated fuel rod is designed according to the size and the structure of the real lead-bismuth reactor fuel rod and is used for accommodating high-pressure gas and aerosol and constructing cladding crevices with different shapes and sizes; the crevasse sealing device is used for sealing a crevasse to construct a closed environment in the fuel rod, the collecting device serves as a containing place for aerosol released by the fuel rod to facilitate subsequent sampling measurement, and the wet particle size analyzer is used for measuring particle size distribution of aerosol particles. The device disclosed by the invention can be used for measuring the release share and the particle size distribution of the aerosol in the fuel rod pellet-cladding gap through the cladding crevasse, and can be used for researching the release characteristics of the aerosol under different fission gas pressures and different crevasse sizes and morphologies.

Description

Technical Field

[0001] This invention belongs to the technical field of fission product release mechanism research, specifically involving an apparatus and method for measuring the aerosol release fraction and particle size distribution under fuel damage in lead-bismuth reactors. Background Technology

[0002] During reactor operation, the fuel assemblies in the reactor core generate a large number of radioactive fission products during fission. However, under the influence of fretting erosion, foreign object erosion, chemical corrosion, irradiation creep and swelling, and the high pressure of fission products within the fuel cladding, the fuel cladding may break, releasing fission products into the coolant. In addition to common fission gases, the fission products released from the break also include non-gaseous fission products such as solid and liquid fission products. In program calculations, liquid and solid fission products are generally simulated using aerosol particles. Currently, in the source term analysis of lead-bismuth reactor mechanisms, the proportion of aerosols released from the break is assumed, introducing uncertainty into the source term calculation results. Therefore, it is urgent to conduct relevant experimental research on the complex physical process of fission products being released from fuel elements into liquid lead-bismuth alloy coolant in lead-bismuth fast reactors to obtain key parameters of the fission product migration process, such as the gas release rate and the total aerosol release proportion after release, to provide support for model development and source term analysis calculations. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention aims to provide an apparatus and method for measuring the aerosol release fraction and particle size distribution under lead-bismuth fuel breakage, which can be used to study the release characteristics of aerosols and fission gases under different fission gas pressures and different breakage sizes and morphologies.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: An apparatus for measuring the aerosol release fraction and particle size distribution under lead-bismuth fuel breakage, comprising a high-pressure gas tank 1, an aerosol weighing device 2, a simulated fuel rod 3, a breakage sealing device 4, a collection device 5, a wet particle size analyzer 6, and pipeline valves and flow and pressure measuring instruments. The high-pressure gas tank 1 is used to provide the gas required for the entire device and is connected to the upper port of the simulated fuel rod 3 through a gas-tight ventilation pipe. The aerosol weighing device 2 is used to weigh the aerosol powder used, so as to provide a specified mass of aerosol to the simulated fuel rod 3. The aerosol is injected through the upper port of the simulated fuel rod 3 to reduce pipeline residue and loss. The simulated fuel rod 3 is used to contain high-pressure aerosol and to construct ruptures of different shapes and sizes on the fuel rod shell. It is designed with reference to the size and structure of the fuel rod in a real lead-bismuth reactor. The front gas enters the simulated fuel rod through the high-pressure gas tank 1, and the rupture sealing device 4 is set on the rupture of the fuel rod shell as a gas outlet. The rupture sealing device 4 has the function of sealing the rupture of the fuel rod casing, and can construct a closed internal space of the fuel rod to carry high-pressure gas. It is set on the simulated fuel rod 3 and serves as a gas outlet when opened. At the same time, the rear end is connected to the collection device 5. The collection device 5 serves as a container for aerosols released from the fuel rods, facilitating subsequent sampling and measurement. It is located at the end of the gas flow path. The released aerosol powder is subsequently collected from the collection device and used by the wet particle size analyzer 6 to measure the particle size distribution. The wet particle size analyzer 6 is used to measure the particle size distribution of aerosol particles in the sample gas and collects the aerosol to be tested from the collection device 5.

[0005] The gas in the high-pressure gas tank 1 is helium; the aerosol powder is silicon dioxide powder.

[0006] The high-pressure gas tank 1 consists of multiple gas tanks to provide sufficient gas to the device. The high-pressure gas tank is connected to the aerosol injection section of the simulated fuel rod 3 through a pressure regulating valve to adjust the upper pressure of the aerosol injection section.

[0007] The aerosol weighing device 2 is mainly composed of a measuring balance, which weighs the aerosol powder and ensures that a specified mass of aerosol is provided to the simulated fuel rod.

[0008] The simulated fuel rod 3 includes an upper plug 3-1, a fuel rod casing 3-2, an inner core block 3-3, a lower plug 3-4, and a positioning post 3-5. The upper plug 3-1, the lower plug 3-4, and the fuel rod casing 3-2 are connected by threads to form the fuel rod as a whole. The fuel rod casing 3-2 and the inner core block 3-3 are connected by the positioning post 3-5. The lower plug 3-4 includes a support rod 3-8 to connect to the inner core block 3-3 and provide support and center positioning. The dimensions of each part of the simulated fuel rod 3 are designed with reference to the dimensions of the fuel rod of a real lead-bismuth fast reactor. At the same time, a pressure gauge 3-6 is placed at the fuel rod casing 3-2 to measure the gas pressure inside the simulated fuel rod. A vent 3-7 is designed on the fuel rod casing 3-2 to release high-pressure gas.

[0009] The breach sealing device 4 includes a breach platform 4-1, a rupture disc 4-2, and a clamping flange 4-3. The internal structure of the breach platform 4-1 is consistent with the shape of the fuel rod casing 3-2 and is smooth enough to ensure that it can fit the fuel rod casing and thus ensure its sealing performance. When sealing the breach, the breach is sealed by installing the rupture disc 4-2 and the clamping flange 4-3 at the breach, while maintaining the balance of the force on the fuel rod. During the experiment, when the internal pressure of the fuel rod reaches the bursting pressure of the rupture disc 4-2, the breach opens and aerosol particles are released outward.

[0010] The collection device 5 serves as a container for aerosols released from the simulated fuel rods and facilitates sampling and measurement. It is connected to the fuel rod casing 3-2 via a rupture sealing device 4.

[0011] The wet particle size analyzer 6 is a measuring instrument used to measure the particle size distribution, particle shape distribution, and count of aerosol particles or droplets collected and released in the collection device 5. The measuring instrument captures images of aerosol particles using a high-resolution digital industrial camera and a backlight system, and performs morphological parameter analysis.

[0012] The method of using the device includes the following steps: Assembly of the simulated fuel rod: Fix the measuring channel of pressure gauge 3-6 to the designated position of the simulated fuel rod, align the internal core block 3-3 of the simulated fuel rod with the positioning stake 3-5 and install it. After assembly, shake the simulated fuel rod 3 to check whether the assembly is secure. Then, according to the working condition settings, select the rupture disc 4-2 that will rupture under the expected burst pressure, and clamp the rupture disc 4-2 between the rupture platform 4-1 and the clamping flange 4-3. Finally, fix the simulated fuel rod 3 in the designated position and prepare to start the experiment. Aerosol injection: The aerosol particles, which are pre-calculated and weighed by the aerosol weighing device 2, are dried and sieved to obtain the required weight. The aerosol powder is poured into the upper plug 3-1 of the simulated fuel rod, and the gas injection channel is fixed by the upper plug 3-1. Finally, the high-pressure gas cylinder 1 is opened to start injecting gas into the simulated fuel rod 3 until the internal pressure of the simulated fuel rod 3 is close to the explosion set value. After standing for a period of time, the aerosol in the simulated fuel rod 3 is uniformly dispersed and deposited in the gas phase. Aerosol release: After the internal pressure of the simulated fuel rod 3 approaches the explosion set value, the gas pressure inside the simulated fuel rod is slowly increased until it explodes; at this time, the rupture disc 4-2 at the rupture point of the fuel rod casing explodes, and the rupture point 3-7 is in the open state. The gas and aerosol inside the fuel rod casing 3-2 begin to be released into the collection device 5; as the gas and aerosol are released, the reading of the pressure gauge 3-6 begins to decrease until the release ends. The reading drops to atmospheric pressure and no longer changes, the release stage ends, the release stage data is recorded, and the aerosol powder in the collection device 5 is collected for the wet particle size analyzer 6 to measure the particle size distribution of the released aerosol particles; Test bench cleaning and repeated experiments: After the release phase, disassemble the breach sealing device 4 and the simulated fuel rod 3, clean the simulated fuel rod to ensure that there are no aerosol particles remaining inside the simulated fuel rod; after cleaning, replace the rupture disc 4-2 under other working conditions and repeat the above process to conduct repeated experiments under the same working conditions. The repeated experiments should be conducted at least twice; after the repeated experiments are completed, the experimental data should be preliminarily sorted out and the data should be checked to see if they match the actual process. Experiments under different working conditions: After the experiment under the same working condition is completed, the working condition is changed to conduct the experiment under the next working condition, and the above experimental steps are repeated. After the experiment is completed, process the experimental data recorded by the data acquisition system and analyze the experimental phenomena and results.

[0013] The technical problem solved and the advantages of this invention are as follows: The technical problem solved by this invention: 1. The device described in this invention solves the problem of measuring the release proportion and particle size distribution of fission products after lead-bismuth pile fuel damage; 2. The device described in this invention solves the problem of difficulty in replicating the actual structural dimensions of lead-bismuth reactor fuel rods in experiments.

[0014] 3. The device described in this invention solves the problem of simulating the opening process of a fuel rod cladding failure under real-world conditions.

[0015] The present invention has the following advantages and beneficial effects: 1. The device of the present invention adopts the structure and size of the fuel rods of an actual lead-bismuth reactor, which is as close as possible to the actual reactor, laying the foundation for the authenticity and reliability of experimental data.

[0016] 2. The gas and aerosol powder of the present invention are helium and silicon dioxide powder, respectively, which have no pollution or harm to the environment and human body. Therefore, they can be directly discharged into the environment, which greatly simplifies the waste collection process of the experiment.

[0017] 3. Due to its special gas supply method (high-pressure gas tank supply), the device of the present invention can increase or decrease the number of gas tanks as needed to meet the time requirements for conducting steady-state experiments.

[0018] 4. The device of the present invention has a simple structure, is easy to process and disassemble, and has high reliability. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the simulated fuel rod structure of the present invention.

[0020] Figure 2This is a schematic diagram of the simulated fuel rod of the present invention.

[0021] Figure 3 This is a schematic diagram of the appearance of the breach sealing device of the present invention.

[0022] 1-High-pressure gas tank, 2-Aerosol weighing device, 3-Simulated fuel rod, 3-1-Upper plug, 3-2-Fuel rod casing, 3-3-Internal pellet, 3-4-Lower plug, 3-5-Positioning stake, 3-6-Pressure gauge, 3-7-Break, 3-8-Support rod, 4-Break sealing device, 4-1-Break platform, 4-2-Rupture disc, 4-3-Pressure flange, 5-Collection device, 6-Wet particle size analyzer. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0024] like Figure 1 As shown, the present invention relates to an apparatus for measuring the aerosol release fraction and particle size distribution under lead-bismuth fuel breakage. The apparatus includes a high-pressure gas tank 1, an aerosol weighing device 2, a simulated fuel rod 3, a break sealing device 4, a collection device 5, a wet particle size analyzer 6, and measuring instruments such as pipelines, valves, and flow and pressure gauges.

[0025] The high-pressure gas tank 1 is used to provide the gas required for the entire device. It is located at the front end of the device and is connected to the simulated fuel rod 3 through a well-sealed ventilation pipe. The aerosol weighing device 2 is used to weigh the aerosol powder used. It provides a specified mass of aerosol to the simulated fuel rod 3 through a metering balance. It is set at the front gas inlet near the simulated fuel rod 3. The aerosol is injected through the upper port of the simulated fuel rod 3 to reduce pipeline residue and loss. The simulated fuel rod 3 is used to contain high-pressure aerosol and to construct ruptures of different shapes and sizes on the fuel rod shell. It is designed with reference to the size and structure of the fuel rod in a real lead-bismuth reactor and is located at the center of the device. The front gas enters the simulated fuel rod through the high-pressure gas tank 1, and the rupture sealing device 4 is set on the rupture of the fuel rod shell as a gas outlet. The rupture sealing device 4 has the function of sealing the rupture of the fuel rod casing, and can construct a closed internal space of the fuel rod to carry high-pressure gas. It is set on the simulated fuel rod 3 and serves as a gas outlet when opened. At the same time, the rear end is connected to the collection device 5. The collection device 5 serves as a container for aerosols released from the fuel rods, facilitating subsequent sampling and measurement. It is located at the end of the gas flow path. The released aerosol powder is subsequently collected from the collection device and used by the wet particle size analyzer 6 to measure the particle size distribution. The wet particle size analyzer 6 is used to measure the particle size distribution of aerosol particles in the sample gas and collects the aerosol to be tested from the collection device 5.

[0026] Preferably, the high-pressure gas tank 1 of the present invention can be composed of multiple gas tanks to provide sufficient gas to the device. The high-pressure gas tank is connected to the aerosol injection section of the simulated fuel rod 3 through a pressure regulating valve, thereby adjusting the upper pressure of the aerosol injection section.

[0027] Preferably, the aerosol weighing device 2 of the present invention is mainly composed of a measuring balance, which weighs the aerosol powder and ensures that a specified mass of aerosol is provided to the simulated fuel rod.

[0028] Preferred, such as Figure 2 As shown, the simulated fuel rod 3 of the present invention includes an upper plug 3-1, a fuel rod casing 3-2, an inner core block 3-3, a lower plug 3-4, and a positioning post 3-5. The upper plug 3-1, the lower plug 3-4, and the fuel rod casing 3-2 are connected by threads to form the fuel rod as a whole. The fuel rod casing 3-2 and the inner core block 3-3 are connected by the positioning post 3-5. The lower plug 3-4 includes a support rod 3-8 to connect the inner core block 3-3 and provide support and center positioning. The dimensions of each part of the simulated fuel rod 3 are designed with reference to the dimensions of the fuel rod of a real lead-bismuth fast reactor. At the same time, a pressure gauge 3-6 is placed at the fuel rod casing 3-2 to measure the gas pressure inside the simulated fuel rod. A vent 3-7 is designed on the fuel rod casing 3-2 for releasing high-pressure gas.

[0029] Preferred, such as Figure 3 As shown, the rupture sealing device 4 of the present invention includes a rupture platform 4-1, a rupture disc 4-2, and a clamping flange 4-3. The internal structure of the rupture platform 4-1 is consistent with the shape of the fuel rod casing 3-2 and is smooth enough to ensure that it can fit the fuel rod casing and thus ensure its sealing performance. When sealing the rupture, the rupture disc 4-2 and the clamping flange 4-3 are installed at the rupture to seal the rupture while maintaining the balance of the force on the fuel rod. During the experiment, when the internal pressure of the fuel rod reaches the bursting pressure of the rupture disc 4-2, the rupture opens and aerosol particles are released outward.

[0030] Preferably, the collection device 5 of the present invention serves as a containment site for aerosols released from the simulated fuel rods and facilitates sampling and measurement, and is connected to the fuel rod casing 3-2 via the rupture sealing device 4.

[0031] Preferably, the wet particle size analyzer 6 of the present invention is a measuring instrument used to measure the particle size distribution, particle shape distribution, and count of aerosol particles or droplets collected in the collection device (5). The measuring instrument captures images of aerosol particles using a high-resolution digital industrial camera and a backlight system, and performs morphological parameter analysis (such as perimeter, area, length, width, diameter, equivalent perimeter diameter, sphericity, convexity, aspect ratio, etc.).

[0032] The method of using the device described in this invention is as follows: Assembling the simulated fuel rod: Fix the measuring channel of pressure gauge 3-6 to the designated position on the simulated fuel rod. Align the internal core block 3-3 of the simulated fuel rod with the positioning stake 3-5 and install it. After assembly, you can slightly shake the simulated fuel rod to check if the assembly is secure. Then, according to the working condition settings, select the rupture disc 4-2 that will explode under the expected burst pressure, and clamp the rupture disc between the rupture platform 4-1 and the clamping flange 4-3. Finally, fix the simulated fuel rod 3 in the designated position, ready to start the experiment.

[0033] Aerosol injection: The aerosol particles, pre-calculated and weighed by the aerosol weighing device 2, are dried and sieved to obtain the required weight. The aerosol powder is poured into the upper plug 3-1 of the simulated fuel rod, and the gas injection channel is fixed by the upper plug 3-1. Finally, the high-pressure gas cylinder 1 is opened to start injecting gas into the simulated fuel rod 3 until the internal pressure of the simulated fuel rod 3 approaches the explosion set value. After standing for a period of time, the aerosol in the simulated fuel rod 3 is uniformly dispersed and deposited in the gas phase.

[0034] Aerosol Release: After the internal pressure of the simulated fuel rod 3 approaches the explosion set value, the gas pressure inside the simulated fuel rod is slowly increased until it explodes. At this time, the rupture disc 4-2 at the rupture point of the fuel rod casing explodes, and the rupture point 3-7 is in the open state. The gas and aerosol inside the fuel rod casing 3-2 begin to be released into the collection device 5. As the gas and aerosol are released, the reading of the pressure gauge 3-6 begins to decrease until the release ends. The reading drops to atmospheric pressure and no longer changes, marking the end of the release phase. The release phase data is recorded, and the aerosol powder in the collection device 5 is collected for the wet particle size analyzer 6 to measure the particle size distribution of the released aerosol particles.

[0035] Test bench cleaning and repeat experiments: After the release phase, disassemble the breach sealing device 4 and the simulated fuel rod 3, clean the simulated fuel rod to ensure that no aerosol particles remain inside. After cleaning, replace the rupture disc 4-2 with one from another operating condition and repeat the above steps to conduct repeat experiments under the same operating condition. The repeat experiments should be conducted at least twice. After the repeat experiments are completed, the experimental data are preliminarily compiled, and the data are checked to see if they match the actual process.

[0036] Experiments under different working conditions: After the experiment under the same working condition (including repeated experiments) is completed, the working condition is changed to conduct the experiment under the next working condition, and the above experimental steps are repeated.

[0037] After the experiment is completed, process the experimental data recorded by the data acquisition system and analyze the experimental phenomena and results.

[0038] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An apparatus for measuring the aerosol release fraction and particle size distribution under lead-bismuth fuel breakage, characterized in that: The device includes a high-pressure gas tank (1), an aerosol weighing device (2), a simulated fuel rod (3), a breach sealing device (4), a collection device (5), a wet particle size analyzer (6), and pipeline valves and flow and pressure measuring instruments; The high-pressure gas tank (1) is used to provide the gas required for the entire device and is connected to the upper port of the simulated fuel rod (3) through a gas-tight ventilation pipe. The aerosol weighing device (2) is used to weigh the aerosol powder used, so as to provide a specified mass of aerosol to the simulated fuel rod (3) and inject the aerosol through the upper port of the simulated fuel rod (3) to reduce pipeline residue and loss. The simulated fuel rod (3) is used to contain high-pressure aerosol and to construct ruptures of different shapes and sizes on the fuel rod shell. It is designed with reference to the size and structure of the fuel rod of the real lead-bismuth pile. The front gas enters the simulated fuel rod through the high-pressure gas tank (1), and the rupture sealing device (4) is set on the rupture of the fuel rod shell as a gas outlet. The rupture sealing device (4) has the function of sealing the rupture of the fuel rod casing, and can construct a closed internal space of the fuel rod to carry high-pressure gas. It is set on the simulated fuel rod (3) and serves as a gas outlet when opened. At the same time, the rear end is connected to the collection device (5). The collection device (5) serves as a container for aerosols released from the fuel rods, facilitating subsequent sampling and measurement. It is located at the end of the gas flow path. The released aerosol powder is then collected from the collection device and used by the wet particle size analyzer (6) to measure the particle size distribution. The wet particle size analyzer (6) is used to measure the particle size distribution of aerosol particles in the sample gas and to collect the aerosol to be tested from the collection device (5).

2. The apparatus according to claim 1, characterized in that, The gas in the high-pressure gas tank (1) is helium; the aerosol powder is silicon dioxide powder.

3. The apparatus according to claim 1, characterized in that, The high-pressure gas tank (1) consists of multiple gas tanks to provide sufficient gas to the device. The high-pressure gas tank is connected to the aerosol injection section of the simulated fuel rod (3) through a pressure regulating valve to adjust the upper pressure of the aerosol injection section.

4. The apparatus according to claim 1, characterized in that, The aerosol weighing device (2) is mainly composed of a measuring balance, which weighs the aerosol powder and ensures that a specified mass of aerosol is provided to the simulated fuel rod.

5. The apparatus according to claim 1, characterized in that, The simulated fuel rod (3) includes an upper plug (3-1), a fuel rod cladding (3-2), an inner core (3-3), a lower plug (3-4), and a positioning post (3-5). The upper plug (3-1), lower plug (3-4), and fuel rod cladding (3-2) are connected by threads to form the fuel rod as a whole. The fuel rod cladding (3-2) and the inner core (3-3) are connected by the positioning post (3-5). The lower plug (3-4) includes a support rod (3-8) to connect the inner core (3-3) and provide support and center positioning. The dimensions of each part of the simulated fuel rod (3) are designed with reference to the dimensions of the actual lead-bismuth fast reactor fuel rod. At the same time, a pressure gauge (3-6) is placed at the fuel rod cladding (3-2) to measure the internal gas pressure of the simulated fuel rod. A vent (3-7) is designed on the fuel rod cladding (3-2) to release high-pressure gas.

6. The apparatus according to claim 1, characterized in that, The rupture sealing device (4) includes a rupture platform (4-1), a rupture disc (4-2), and a clamping flange (4-3). The internal structure of the rupture platform (4-1) is consistent with the shape of the fuel rod casing (3-2) and is smooth enough to ensure that it can fit the fuel rod casing and thus ensure its sealing performance. When sealing the rupture, the rupture is sealed by installing the rupture disc (4-2) and the clamping flange (4-3) at the rupture, while maintaining the balance of the force on the fuel rod. During the experiment, when the internal pressure of the simulated fuel rod reaches the bursting pressure of the rupture disc (4-2), the rupture opens and releases aerosol particles to the outside.

7. The apparatus according to claim 1, characterized in that, The collection device (5) serves as a container for aerosols released from the simulated fuel rods and facilitates sampling and measurement. It is connected to the fuel rod casing (3-2) via a rupture sealing device (4).

8. The apparatus according to claim 1, characterized in that, The wet particle size analyzer (6) is a measuring instrument used to measure the particle size distribution, particle shape distribution and count of aerosol particles or droplets collected and released in the collection device (5); the measuring instrument captures images of aerosol particles using a high-resolution digital industrial camera and a backlight system and performs morphological parameter analysis.

9. A method of using the apparatus as described in any one of claims 1-8, characterized in that, The method includes the following steps: Assembly of the simulated fuel rod: Fix the measuring channel of the pressure gauge (3-6) to the designated position of the simulated fuel rod, align the internal core block (3-3) of the simulated fuel rod with the positioning stake (3-5) and install it. After assembly, shake the simulated fuel rod (3) to check whether it is firmly assembled. Then, according to the working condition settings, select the rupture disc (4-2) that will rupture under the expected burst pressure, and clamp the rupture disc (4-2) between the rupture platform (4-1) and the clamping flange (4-3). Finally, fix the simulated fuel rod (3) in the designated position and prepare to start the experiment. Aerosol injection: The aerosol particles are pre-calculated and weighed by the aerosol weighing device (2). After drying and sieving, the required weight is obtained. The aerosol powder is poured into the upper plug (3-1) of the simulated fuel rod. The gas injection channel is fixed by the upper plug (3-1). Finally, the high-pressure gas cylinder (1) is opened to start injecting gas into the simulated fuel rod (3) until the internal pressure of the simulated fuel rod (3) is close to the explosion set value. After standing for a period of time, the aerosol in the simulated fuel rod (3) is uniformly dispersed and deposited in the gas phase. Release of aerosols: After the internal pressure of the simulated fuel rod (3) approaches the explosion set value, the gas pressure inside the simulated fuel rod is slowly increased until it explodes; at this time, the rupture disc (4-2) at the rupture of the fuel rod casing explodes, the rupture (3-7) is in the open state, and the gas and aerosol inside the fuel rod casing (3-2) begin to be released into the collection device (5); as the gas and aerosols are released, the reading of the pressure gauge (3-6) begins to drop until the release ends, the reading drops to atmospheric pressure and no longer changes, the release stage ends, the release stage data is recorded, and the aerosol powder in the collection device (5) is collected for the wet particle size analyzer (6) to measure the particle size distribution of the released aerosol particles; Test bench cleaning and repeated experiments: After the release phase, disassemble the rupture sealing device (4) and the simulated fuel rod (3), clean the simulated fuel rod to ensure that there are no aerosol particles left in the simulated fuel rod; after cleaning, replace the rupture disc (4-2) under other working conditions and repeat the above process to conduct repeated experiments under the same working conditions. The repeated experiments should be conducted at least twice; after the repeated experiments are completed, the experimental data should be preliminarily sorted out and the data should be checked to see if they match the actual process. Experiments under different working conditions: After the experiment under the same working condition is completed, the working condition is changed to conduct the experiment under the next working condition, and the above experimental steps are repeated. After the experiment is completed, process the experimental data recorded by the data acquisition system and analyze the experimental phenomena and results.

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