Device and method for measuring aerosol release share and rate at lead-bismuth reactor fuel crevasse

Abstract

The invention discloses a device and a method for measuring aerosol release share and rate at a lead-bismuth reactor fuel crevasse. The device comprises a high-pressure gas tank, an aerosol mixing device, a simulation fuel rod, a crevasse sealing device, a collecting device, a particle size spectrometer, a pipeline valve, flow, pressure and other measuring instruments. The high-pressure gas tank is used for providing needed gas, the aerosol mixing device is used for mixing the gas and used aerosol powder, and the simulation fuel rod is designed according to the size and the structure of the real lead-bismuth reactor fuel rod and used for containing high-pressure aerosol and constructing cladding crevices of different shapes and sizes. The crevasse sealing device is used for sealing the crevasse to construct a closed environment in the fuel rod, the collecting device serves as an aerosol accommodating place to facilitate subsequent sampling measurement, and the particle size spectrometer is used for measuring the aerosol particle concentration of sample gas. The device can complete the measurement of the release share of the aerosol in the fuel rod pellet-cladding gap through the cladding crevasse and the release rate of the gas through the crevasse, and is used for researching the release characteristics of the aerosol and the fission gas under different fission gas pressures and different crevasse sizes and morphologies.

Description

Technical Field

[0001] The invention belongs to the technical field of research on the release mechanism of fission products, and in particular relates to a device and a method for measuring the aerosol release fraction and rate at a lead-bismuth pile fuel breach. Background Art

[0002] When the reactor is in operation, the core fuel assembly will produce a large amount of radioactive fission products during the fission process. However, under the action of micro-abrasion, foreign body abrasion, chemical corrosion, irradiation creep and swelling, and the high pressure of fission products in the fuel cladding, the fuel cladding may be damaged, thereby releasing fission products into the coolant. In addition to the common fission gases, the fission products released from the breach also include non-gaseous fission products such as solid fission products and liquid fission products. In the program calculation, liquid and solid fission products are generally simulated by aerosol particles. At present, in the process of conducting the source term analysis of the lead-bismuth reactor mechanism, the aerosol fraction released from the breach is assumed to have an assumed value, which introduces uncertainty into the source term calculation results. Therefore, it is urgent to conduct relevant experimental research on the complex physical process of the release of fission products from fuel elements to liquid lead-bismuth alloy coolant in the lead-bismuth fast reactor to obtain the key parameters of the fission product migration process, such as the gas release rate and the total release fraction of the aerosol after the release, so as to provide support for model development and source term analysis calculation. Summary of the invention

[0003] To solve the above problems, the purpose of the present invention is to provide a device and method for measuring the aerosol release fraction and rate at the rupture of lead-bismuth pile fuel, which can be used to study the release characteristics of aerosol and fission gas under different fission gas pressures and different rupture sizes and morphologies.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A device for measuring the aerosol release ratio and rate at the breach of lead-bismuth pile fuel, the device comprising a high-pressure gas tank 1, an aerosol mixing device 2, a simulated fuel rod 3, a breach sealing device 4, a collecting device 5, a particle size spectrometer 6, a pipeline valve and a flow pressure measuring instrument;

[0006] The high-pressure gas tank 1 is used to provide the gas required by the entire device, is arranged at the front end of the device, and is connected to the aerosol mixing device 2 through a ventilation pipe;

[0007] The aerosol mixing device 2 is used to uniformly mix the gas and the aerosol powder used, and provide aerosol of a specified concentration to the simulated fuel rod 3. It is arranged near the front gas inlet of the simulated fuel rod 3 and connected to the simulated fuel rod 3 through a ventilation pipe to ensure that the aerosol enters quickly after mixing and reduce pipeline residue;

[0008] The simulated fuel rod 3 is used to contain high-pressure aerosol and to construct holes of different shapes and sizes on the fuel rod cladding, and the front gas enters the simulated fuel rod 3 through the high-pressure gas tank 1 and the aerosol mixing device 2 in turn with reference to the size and structure design of the real lead-bismuth pile fuel rod;

[0009] The breach sealing device 4 has the function of sealing the breach of the simulated fuel rod, and can construct a closed internal space of the simulated fuel rod to carry high-pressure gas. It is arranged on the simulated fuel rod 3 as a gas outlet, and the rear end is connected to the collecting device 5;

[0010] The collecting device 5 is used as a place to contain the aerosol after the simulated fuel rod is released, which is convenient for subsequent sampling and measurement. It is located at the end of the gas flow path, and a gas measurement pipeline is led out from it to connect to the particle size spectrometer 6;

[0011] The particle size spectrometer 6 is used to measure the aerosol particle concentration of the sample gas, and collects the measured gas from the collecting device 5 .

[0012] The high-pressure gas tank 1 is composed of a plurality of gas tanks to provide sufficient gas to the aerosol mixing device 2. The high-pressure gas tank is connected to the aerosol injection section of the aerosol mixing device 2 through a gas tank pressure regulating valve 7 to adjust the upper end pressure of the aerosol injection section.

[0013] The gas in the high-pressure gas tank 1 is helium.

[0014] The main body of the aerosol mixing device 2 is composed of a mixing device shell 2-2 and a rotating screw 2-1 located in the shell 2-2. The mixing device shell 2-2 is provided with a mixing device gas inlet 2-3 and a mixing device aerosol outlet 2-4. The motor 2-5 provides power to drive the rotating screw rotating shaft 2-6 to rotate so as to rotate the rotating screw 2-1. Aerosol powder 2-7 is arranged at the bottom of the mixing device shell 2-2. The rotating screw 2-1 rotates to drive the aerosol powder 2-7 to move upward so as to mix with the incoming gas to form an aerosol.

[0015] The aerosol powder 2-7 is titanium dioxide powder.

[0016] The simulated fuel rod 3 is composed of an upper end plug 3-1, a fuel rod cladding 3-2 and an internal core block unit. The upper end plug 3-1 and the fuel rod cladding 3-2 are threadedly connected to form a fuel rod as a whole, wherein the core block unit is composed of a spring 3-3 and a core block 3-4 connected to each other. The dimensions of each part of the simulated fuel rod 3 are designed with reference to the dimensions of a real lead-bismuth fast reactor fuel rod; a fuel rod pressure gauge 3-8 is placed at the upper end plug 3-1 to measure the internal gas pressure of the simulated fuel rod, and a rupture 3-5, a gas injection port 3-6 and a sampling port 3-7 are designed on the fuel rod cladding 3-2, which are respectively used to release high-pressure gas, inject high-pressure gas into the simulated fuel rod and sample and measure the high-pressure gas.

[0017] The breach closing device 4 includes two sealing devices relatively arranged on the simulated fuel rod 3, each sealing device includes a pressure cap 4-1 and a pressure rod 4-2, the two pressure caps 4-1 are butted, the internal structure of the pressure cap 4-1 is consistent with the shape of the fuel rod cladding and is smooth to ensure that it can fit the fuel rod cladding to ensure its sealing. When sealing the breach, a force along the radial direction of the simulated fuel rod is applied to the pressure rods 4-2 of the two sealing devices so that the two sealing devices can close the breach while keeping the force on the fuel rod balanced. When opening the breach, the radial force is removed and the breach closing device 4 is moved to expose the breach.

[0018] The collecting device shell 5-1 of the collecting device 5 is integrated with the fuel rod cladding 3-2, serving as a place to contain aerosols released from the simulated fuel rods and facilitating sampling and measurement. Samples are sucked through a sampling tube 5-2 arranged on the collecting device shell 5-1.

[0019] 9. The device for measuring the aerosol release proportion and rate at the breach of lead-bismuth pile fuel according to claim 1 is characterized in that the particle size spectrometer 6 includes a scanning mobility particle size spectrometer 6-1 and a pre-measurement channel 6-2 directly connected to the scanning mobility particle size spectrometer 6-1, an in-cladding measurement channel 6-4, a collecting device measurement channel 6-6, and a residual gas cleaning channel 6-9; the pre-measurement channel 6-2 is provided with a pre-measurement channel valve 6-3, the in-cladding measurement channel 6-4 is provided with an in-cladding measurement channel valve 6-5, the collecting device measurement channel 6-6 is provided with a collecting device measurement channel valve 6-7, and the residual gas cleaning channel 6-9 is provided with a residual gas cleaning channel valve 6-8.

[0020] Technical problems and advantages solved by the present invention:

[0021] Technical problems solved by the present invention:

[0022] 1) The device of the present invention solves the problem of measuring the release proportion and rate of fission products after the lead-bismuth pile fuel is damaged;

[0023] 2) The device described in the present invention solves the problem that it is difficult to restore the structural dimensions of the real lead-bismuth stack fuel rods in experiments.

[0024] The present invention has the following advantages and beneficial effects:

[0025] 1) The device of the present invention adopts the structure and size of the actual lead-bismuth reactor fuel rod, which is as close to the actual reactor as possible, laying a foundation for the authenticity and reliability of the experimental data.

[0026] 2) The gas and aerosol powder of the present invention respectively use helium and titanium dioxide powder, which are non-polluting and harmless to the environment and human body, and can therefore be directly discharged into the environment, greatly simplifying the waste collection link of the experiment.

[0027] 3) Due to its special gas supply method (gas supply by high-pressure gas cylinders), the device of the present invention can increase or decrease the number of gas cylinders according to demand to meet the time requirement for conducting steady-state experiments.

[0028] 4) The device of the present invention has a simple structure, is easy to process and disassemble, and has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0030] Figure 1 The present invention is a schematic diagram of a device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach.

[0031] Figure 2 It is a schematic structural diagram of the aerosol mixing device of the present invention.

[0032] Figure 3 It is a schematic diagram of the simulated fuel rod structure of the present invention.

[0033] Figure 4 It is a schematic diagram of the appearance of the breach sealing device of the present invention.

[0034] Figure 5 It is a schematic diagram of the appearance of the collecting device of the present invention.

[0035] Figure 6 It is a schematic diagram of the appearance of the measurement system of the present invention.

[0036] 1-high pressure gas tank, 2-aerosol mixing device, 2-1-rotating screw, 2-2-mixing device housing, 2-3-gas inlet, 2-4-mixing device aerosol outlet, 2-5-motor, 2-6-rotating screw rotating shaft, 2-7-aerosol powder, 3-simulated fuel rod, 3-1-upper end plug, 3-2-fuel rod cladding, 3-3-spring, 3-4-core block (the lower part contains a cavity), 3-5-break, 3-6-gas injection port, 3-7-sampling port, 3-8-fuel rod pressure gauge, 4-break closing device, 4-1-pressure cover, 4-2-pressure rod, 5-collecting device, 5-1-collecting device housing, 5-2-sampling tube, 6-particle size spectrometer, 6-1-scanning mobility particle size spectrometer, 6-2-pre-measurement channel, 6-3-pre-measurement channel valve, 6-4-measuring channel inside the cladding, 6-5-measuring channel valve inside the cladding, 6-6-collecting device measurement channel, 6-7-collecting device measurement channel valve, 6-8-residual gas cleaning channel valve, 6-9-residual gas cleaning channel, 7-gas tank pressure regulating valve, 8-stable bypass pressure regulating valve, 9-fuel rod sampling pressure regulating valve. DETAILED DESCRIPTION

[0037] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0038] like Figure 1 As shown, the present invention provides a device for measuring the aerosol release proportion and rate at the breach of lead-bismuth pile fuel, the device comprising a high-pressure gas tank 1, an aerosol mixing device 2, a simulated fuel rod 3, a breach sealing device 4, a collecting device 5, a particle size spectrometer 6 and measuring instruments such as pipeline valves and flow pressure.

[0039] The high-pressure gas tank 1 is used to provide the gas required by the entire device, is arranged at the front end of the device, and is connected to the aerosol mixing device 2 through a ventilation pipe with good airtightness;

[0040] The aerosol mixing device 2 is used to uniformly mix the gas and the aerosol powder used, and provide the simulated fuel rod with a specified concentration of aerosol. It is arranged near the front gas inlet of the simulated fuel rod 3, and is connected to the simulated fuel rod 3 through a ventilation pipe with good airtightness, so as to ensure that the aerosol enters quickly after mixing and reduce the pipeline residue;

[0041] The simulated fuel rod 3 is used to contain high-pressure aerosol and to construct holes of different shapes and sizes on the cladding. It is designed with reference to the size and structure of the real lead-bismuth pile fuel rod and is arranged at the center of the device. The front gas enters the device through the high-pressure gas tank 1 and the aerosol mixing device 2 in sequence.

[0042] The breach sealing device 4 has the function of sealing the breach of the fuel rod, and can construct a closed internal space of the simulated fuel rod to carry high-pressure gas. It is arranged on the simulated fuel rod 3 as a gas outlet, and the rear end is connected to the collecting device 5;

[0043] The collecting device 5 is used as a place to contain the aerosol after being released from the fuel rod, which is convenient for subsequent sampling and measurement. It is located at the end of the gas flow path, and a gas measurement pipeline is led out from it to connect to the particle size spectrometer 6;

[0044] The particle size spectrometer 6 is used to measure the aerosol particle concentration of the sample gas, and collects the measured gas from the collecting device 5 .

[0045] 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, and the high-pressure gas tank is connected to the aerosol injection section of the aerosol mixing device 2 through the gas tank pressure regulating valve 7 to adjust the upper end pressure of the aerosol injection section. More preferably, the gas in the high-pressure gas tank 1 is helium.

[0046] Preferably, Figure 2 As shown, the main body of the aerosol mixing device 2 of the present invention is composed of a mixing device housing 2-2 and a rotating screw 2-1 located in the housing 2-2. The mixing device housing 2-2 is provided with a mixing device gas inlet 2-3 and a mixing device aerosol outlet 2-4. The motor 2-5 provides power to drive the rotating screw rotating shaft 2-6 to rotate so as to rotate the rotating screw 2-1. Aerosol powder 2-7 is arranged at the bottom of the mixing device housing 2-2. The rotating screw 2-1 rotates to drive the aerosol powder 2-7 to move upward so as to mix with the incoming gas to form an aerosol. More preferably, the aerosol powder 2-7 is titanium dioxide powder.

[0047] Preferably, Figure 3 As shown, the simulated fuel rod 3 of the present invention is composed of an upper end plug 3-1, a fuel rod cladding 3-2 and an internal pellet unit, and the upper end plug 3-1 and the fuel rod cladding 3-2 are connected by threads to form a fuel rod as a whole, wherein the pellet unit is composed of a spring 3-3 and a pellet 3-4 (the lower part contains a cavity), and the dimensions of each part of the simulated fuel rod 3 are designed with reference to the dimensions of a real lead-bismuth fast reactor fuel rod. At the same time, a fuel rod pressure gauge (3-8) is placed at the upper end plug 3-1 to measure the internal gas pressure of the simulated fuel rod, and a breach 3-5, a gas injection port 3-6 and a sampling port 3-7 are designed on the fuel rod cladding 3-2, which are respectively used to release high-pressure gas, inject high-pressure gas into the simulated fuel rod, and sample and measure the high-pressure gas.

[0048] Preferably, Figure 4As shown, the breach sealing device 4 of the present invention includes two sealing devices relatively arranged on the simulated fuel rod 3, each sealing device is composed of a pressure cap 4-1 and a pressure rod 4-2, the two pressure caps 4-1 are butted, the internal structure of the pressure cap 4-1 is consistent with the shape of the fuel rod cladding and is smooth enough to ensure that it can fit the fuel rod cladding to ensure its sealing performance, when sealing the breach, a force along the radial direction of the fuel rod is applied to the pressure rods 4-2 of the two sealing devices so that the two sealing devices can close the breach and keep the force on the fuel rod balanced at the same time, and when opening the breach, the radial force is removed to move the sealing device to expose the breach.

[0049] Preferably, Figure 5 As shown, the collecting device shell 5-1 of the collecting device 5 of the present invention is integrated with the fuel rod cladding 3-2, serving as a place to contain aerosols released from the fuel rods and facilitating sampling and measurement, and the sample is sucked through the sampling tube 5-3.

[0050] Preferably, Figure 6 As shown, the particle size spectrometer 6 of the present invention includes a scanning mobility particle size spectrometer 6-1 and a pre-measurement channel 6-2 directly connected to the scanning mobility particle size spectrometer 6-1, an in-cladding measurement channel 6-4, a collecting device measurement channel 6-6, and a residual gas cleaning channel 6-9; the pre-measurement channel 6-2 is provided with a pre-measurement channel valve 6-3, the in-cladding measurement channel 6-4 is provided with an in-cladding measurement channel valve 6-5, the collecting device measurement channel 6-6 is provided with a collecting device measurement channel valve 6-7, and the residual gas cleaning channel 6-9 is provided with a residual gas cleaning channel valve 6-8.

[0051] Example 1

[0052] Before starting use, assemble the entire device and check it to ensure that all systems are working properly, all connections are well sealed, there is no obvious damage or leakage, and the gas supply meets the experimental needs.

[0053] After the whole device is assembled, the simulated fuel rod rupture 4-3 is sealed by applying a tightening force to the rupture sealing device 4, the corresponding valve of the gas bypass of the aerosol injection section is opened, and gas is injected into the simulated fuel rod 3. The gas injection is terminated after observing the pressure gauge 3-8 to the specified pressure of the working condition. Let it stand for a sufficient time and continue to observe the reading of the pressure gauge 3-8. If the reading decreases significantly, the simulated fuel rod needs to be reassembled and sealed. If the reading is basically stable at the set working condition, it means that the simulated fuel rod has good airtightness and meets the requirements of subsequent experiments.

[0054] A certain amount of aerosol powder 2-7 is placed in the aerosol mixing device 2 and the device motor 2-5 is turned on. After the powder transported by the rotating screw 2-1 is stable, the high-pressure gas tank 1 and the gas tank pressure regulating valve 7 are opened to inject gas into the mixing device 2 at a specified pressure. At this time, the stable bypass pressure regulating valve 8 is opened to discharge the aerosol outward through the aerosol stable bypass. After a certain period of time, the pre-measurement channel valve 6-3 is opened to absorb the aerosol in the aerosol stable bypass through the measuring channel 6-2 to measure the aerosol concentration at different times. After the aerosol concentration is stable, the stable bypass pressure regulating valve 8 is closed to connect the injection section to the simulated fuel rod, and the aerosol is injected into the simulated fuel rod 3 to the specified pressure.

[0055] After the aerosol injection is completed, the entire device is left to stand for a long enough time to ensure that the aerosol in the simulated fuel rod can be fully deposited, the pressure regulating valve 9 on the simulated fuel rod 3 is opened, a small amount of gas in the simulated fuel rod 3 is discharged through the sampling port 3-7, and then the fuel rod sampling pressure regulating valve 9 is closed, and the particle size spectrometer 6 is turned on to absorb a small amount of sample through the measurement channel 6-4 in the cladding for measurement.

[0056] The breach 4-3 is opened by the breach sealing device 4, and the gas begins to be released. When the fuel rod pressure gauge 3-8 shows a substantially stable atmospheric pressure, the gas release is finished, and the particle size spectrometer 6 is turned on to absorb a certain amount of sample gas in the collecting device 5 through the collecting device measurement channel 6-6 for measurement.

[0057] Clean the aerosol in the collection device 5, open the gas bypass to purge and clean the entire device, record and organize the experimental data, and obtain the change law of aerosol release ratio. According to the different working conditions set, change the working conditions and conduct the experiment in the same way.

[0058] Example 2

[0059] Before starting use, assemble the entire device and check it to ensure that all systems are working properly, all connections are well sealed, there is no obvious damage or leakage, and the gas supply meets the experimental needs.

[0060] After the whole device is assembled, the breach 3-5 of the simulated fuel rod is sealed by applying a tightening force to the breach sealing device 4, the corresponding valve of the gas bypass of the aerosol injection section is opened, and gas is injected into the simulated fuel rod 3. The fuel rod pressure gauge 3-8 is observed to terminate the gas injection after reaching the specified pressure of the working condition. The fuel rod pressure gauge 3-8 is left to stand for a sufficient time and the reading of the fuel rod pressure gauge 3-8 is continuously observed. If the reading decreases significantly, the simulated fuel rod needs to be reassembled and sealed. If the reading is basically stable at the set working condition, it indicates that the simulated fuel rod has good air tightness and meets the requirements of subsequent experiments.

[0061] Start the gas bypass of the aerosol injection section, inject gas into the simulated fuel rod 3 until the fuel rod pressure gauge 3-8 shows the specified operating pressure, and close the aerosol injection section.

[0062] Adjust the outlet pressure of the gas tank pressure regulating valve 7 according to the preset pressure, open the aerosol injection section again and operate the breach sealing device 4 to open the breach at the same time. Adjust the injection pressure of the gas tank pressure regulating valve 7 based on the fuel rod pressure gauge 3-8 reading being stable at the set working condition value to ensure that the fuel rod pressure gauge 3-8 reading remains unchanged. The flow meter reading of the aerosol injection section is the flow rate of the breach 3-5. After the specified injection time, close the aerosol injection section and the experiment ends.

[0063] Clean up the entire device, record and organize the experimental data, and obtain the law of gas release rate changes. According to the different working conditions set, change the working conditions and use the same method to explore the effects of different internal pressures and rupture sizes on gas release rate.

[0064] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.

Claims

1. A device for measuring the aerosol release ratio and rate at the breach of lead-bismuth pile fuel, characterized in that: The device comprises a high-pressure gas tank (1), an aerosol mixing device (2), a simulated fuel rod (3), a breach sealing device (4), a collecting device (5), a particle size spectrometer (6), a pipeline valve and a flow pressure measuring instrument; The high-pressure gas tank (1) is used to provide the gas required by the entire device, is arranged at the front end of the device, and is connected to the aerosol mixing device (2) through a ventilation pipe; The aerosol mixing device (2) is used to uniformly mix the gas and the aerosol powder used, and provide aerosol of a specified concentration to the simulated fuel rod (3). It is arranged near the front gas inlet of the simulated fuel rod (3) and connected to the simulated fuel rod (3) through a ventilation pipe to ensure that the aerosol enters quickly after mixing, thereby reducing pipeline residue. The simulated fuel rod (3) is used to contain high-pressure aerosol and to construct holes of different shapes and sizes on the fuel rod cladding, and is designed with reference to the size and structure of real lead-bismuth pile fuel rods, and the front gas enters the simulated fuel rod (3) through the high-pressure gas tank (1) and the aerosol mixing device (2) in sequence; The breach sealing device (4) has the function of sealing the breach of the simulated fuel rod, can construct a closed internal space of the simulated fuel rod to carry high-pressure gas, is arranged on the simulated fuel rod (3) as a gas outlet, and is connected to a collecting device (5) at the rear end; The collecting device (5) serves as a place to contain the aerosol after being released from the simulated fuel rod, facilitating subsequent sampling and measurement. The collecting device (5) is located at the rear end of the gas flow path, and a gas measurement pipeline is led out from the inside to connect to the particle size spectrometer (6); The particle size spectrometer (6) is used to measure the aerosol particle concentration of the sample gas, and collects the measured gas from the collection device (5).

2. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 1, characterized in that: The high-pressure gas tank (1) is composed of a plurality of gas tanks to provide a sufficient amount of gas to the aerosol mixing device (2). The high-pressure gas tank is connected to the aerosol injection section of the aerosol mixing device (2) via a gas tank pressure regulating valve (7) to adjust the upper end pressure of the aerosol injection section.

3. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 2, characterized in that: The gas in the high-pressure gas tank (1) is helium.

4. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 1, characterized in that: The main body of the aerosol mixing device (2) is composed of a mixing device shell (2-2) and a rotating screw (2-1) located in the shell (2-2); the mixing device shell (2-2) is provided with a mixing device gas inlet (2-3) and a mixing device aerosol outlet (2-4); a motor (2-5) provides power to drive a rotating screw shaft (2-6) to rotate, thereby rotating the rotating screw (2-1); aerosol powder (2-7) is arranged at the bottom of the mixing device shell (2-2); the rotating screw (2-1) rotates to drive the aerosol powder (2-7) to move upward, thereby mixing with the incoming gas to form an aerosol.

5. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 4, characterized in that: The aerosol powder (2-7) is titanium dioxide powder.

6. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 1, characterized in that: The simulated fuel rod (3) is composed of an upper end plug (3-1), a fuel rod cladding (3-2) and an internal pellet unit. The upper end plug (3-1) and the fuel rod cladding (3-2) are connected by threads to form a fuel rod as a whole, wherein the pellet unit is composed of a spring (3-3) and a pellet (3-4) connected to each other. The dimensions of each part of the simulated fuel rod (3) are designed with reference to the dimensions of a real lead-bismuth fast reactor fuel rod. A fuel rod pressure gauge (3-8) is placed at the upper end plug (3-1) to measure the internal gas pressure of the simulated fuel rod. A rupture (3-5), a gas injection port (3-6) and a sampling port (3-7) are designed on the fuel rod cladding (3-2), which are respectively used to release high-pressure gas, inject high-pressure gas into the simulated fuel rod and sample and measure the high-pressure gas.

7. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 1, characterized in that: The breach closing device (4) comprises two sealing devices arranged relatively on the simulated fuel rod (3), each sealing device comprising a pressure cap (4-1) and a pressure rod (4-2), the two pressure caps (4-1) are butt-jointed, the internal structure of the pressure cap (4-1) is consistent with the shape of the fuel rod cladding and is smooth to ensure that it can fit the fuel rod cladding and thus ensure its sealing performance. When sealing the breach, a force along the radial direction of the simulated fuel rod is applied to the pressure rods (4-2) of the two sealing devices so that the two sealing devices can close the breach while maintaining the balance of force on the fuel rod. When opening the breach, the radial force is removed to move the breach closing device (4) to expose the breach.

8. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 1, characterized in that: The collecting device shell (5-1) of the collecting device (5) is integrated with the fuel rod cladding (3-2), serving as a place to contain aerosols released from the simulated fuel rods and facilitating sampling and measurement. The sample is sucked through a sampling tube (5-2) arranged on the collecting device shell (5-1).

9. The device for measuring the aerosol release ratio and rate at the lead-bismuth pile fuel breach according to claim 1, characterized in that: The particle size spectrometer (6) comprises a scanning mobility particle size spectrometer (6-1), a pre-measurement channel (6-2) directly connected to the scanning mobility particle size spectrometer (6-1), an in-cladding measurement channel (6-4), a collection device measurement channel (6-6), and a residual gas cleaning channel (6-9); the pre-measurement channel (6-2) is provided with a pre-measurement channel valve (6-3), the in-cladding measurement channel (6-4) is provided with an in-cladding measurement channel valve (6-5), the collection device measurement channel (6-6) is provided with a collection device measurement channel valve (6-7), and the residual gas cleaning channel (6-9) is provided with a residual gas cleaning channel valve (6-8).

10. A method for using the device for measuring the aerosol release fraction and rate at the lead-bismuth pile fuel breach as claimed in any one of claims 1 to 9, characterized in that: The method comprises the following steps: Conduct a transient experiment to explore the changing law of aerosol release ratio: Before starting to use, assemble the entire device and check to ensure that all components are working properly, all connections are well sealed, there is no obvious damage or leakage, and the gas supply meets the experimental requirements; After the whole device is assembled, the breach (3-5) of the simulated fuel rod is sealed by applying a tightening force to the breach sealing device (4), the corresponding valve of the aerosol injection section is opened, gas is injected into the simulated fuel rod (3), and the fuel rod pressure gauge (3-8) is observed to stop the gas injection after reaching the specified pressure of the working condition. The fuel rod pressure gauge (3-8) is left to stand for a sufficient time and the reading is continuously observed. If the reading decreases significantly, the simulated fuel rod (3) needs to be reassembled and sealed. If the reading is stable at the set working condition, it means that the simulated fuel rod (3) has good airtightness and meets the requirements of subsequent experiments. A preset amount of aerosol powder (2-7) is placed in the aerosol mixing device (2) and the motor (2-5) is turned on. After the rotating screw (2-1) transports the powder to stabilize, the high-pressure gas tank (1) and the gas tank pressure regulating valve (7) are turned on to inject gas into the aerosol mixing device (2) at a specified pressure. At this time, the stabilizing bypass pressure regulating valve (8) is turned on to discharge the aerosol outward through the aerosol stabilizing bypass. After a preset time, the pre-measurement channel valve (6-3) is turned on to absorb the aerosol in the aerosol stabilizing bypass through the pre-measurement channel (6-2) to measure the aerosol concentration at different times. After the aerosol concentration stabilizes, the stabilizing bypass pressure regulating valve (8) is turned off to connect the aerosol mixing device (2) to the simulated fuel rod (3), and the aerosol is injected into the simulated fuel rod (3) to a specified pressure. After the aerosol injection is completed, the entire device is left to stand still to ensure that the aerosol in the simulated fuel rod (3) can be fully deposited, and after the gas in the simulated fuel rod (3) is sampled through the sampling port (3-7), the particle size spectrometer (6) is turned on to absorb the sample through the measurement channel (6-4) in the cladding for measurement; The breach (3-5) is opened by the breach sealing device (4), and the gas begins to be released. When the fuel rod pressure gauge (3-8) shows a stable atmospheric pressure, the gas release is completed, and the particle size spectrometer (6) is turned on to absorb the sample gas in the collection device (5) through the collection device measurement channel (6-6) for measurement; Clean the aerosol in the collection device (5), purge and clean the entire device, record and organize the experimental data, and obtain the change law of the aerosol release ratio; according to the different set working conditions, change the working conditions and conduct the experiment according to the same method; Conduct a steady-state experiment to explore the changing law of gas release rate: Before starting to use, assemble the entire device and check to ensure that all components are working properly, all connections are well sealed, there is no obvious damage or leakage, and the gas supply meets the experimental requirements; After the whole device is assembled, the breach (3-5) of the simulated fuel rod is sealed by applying a tightening force to the breach sealing device (4), the corresponding valve of the aerosol injection section is opened, gas is injected into the simulated fuel rod (3), and the fuel rod pressure gauge (3-8) is observed to terminate the gas injection after reaching the specified pressure of the working condition. The device is left to stand for a preset time and the reading of the fuel rod pressure gauge (3-8) is continuously observed. If the reading decreases significantly, the simulated fuel rod (3) needs to be reassembled and sealed. If the reading is stable at the set working condition, it indicates that the simulated fuel rod (3) has good airtightness and meets the requirements of subsequent experiments. Starting the gas bypass of the aerosol injection section, injecting gas into the simulated fuel rod (3) until the fuel rod pressure gauge (3-8) shows a specified operating pressure, and closing the aerosol injection section; The outlet pressure of the gas tank pressure regulating valve (7) is adjusted according to the preset pressure, the aerosol injection section is opened again and the breach sealing device (4) is operated at the same time to open the breach; the injection pressure of the gas tank pressure regulating valve (7) is adjusted based on the indication of the fuel rod pressure gauge (3-8) being stable at the set working condition value, so as to ensure that the indication of the fuel rod pressure gauge (3-8) remains unchanged, and the flow meter indication of the aerosol injection section is the flow rate of the breach (3-5); after the specified injection time, the aerosol injection section is closed and the experiment ends; Clean and organize the entire device, record and organize the experimental data, and obtain the changing law of gas release rate; according to the different set working conditions, change the working conditions, and use the same method to explore the effects of different internal pressures and rupture sizes on the gas release rate.

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