Liquid lead-bismuth environment fission product evaporation behavior test system and method

Abstract

The application belongs to the technical field of lead-bismuth fast reactor supporting test, and particularly relates to a liquid lead-bismuth environment fission product evaporation behavior test system and method. The application comprises a reaction tank, a temperature control system, an atmosphere control system, a reactant storage system and a sampling analysis system; the reaction tank is used for bearing liquid lead-bismuth and fission products, the temperature control system is used for realizing accurate control of the temperature of the reaction tank; the atmosphere control system is used for providing a controllable gas phase environment, the reactant storage system is used for storing iodine and cesium iodide, quantitative injection of iodine and cesium iodide is realized by adjusting inert gas pressure and flow of an inert gas driven injection unit, and the sampling analysis system is used for realizing measurement of evaporation product composition and particle size distribution. The application realizes accurate regulation and control of temperature, pressure and gas phase environment through modular design, and can carry out saturated vapor partial pressure, evaporation rate and aerosol characteristic research of fission products.

Description

Technical Field

[0001] This invention belongs to the technical field of lead-bismuth fast reactor supporting test technology, specifically relating to a test system and method for the evaporation behavior of fission products in liquid lead-bismuth environment. Background Technology

[0002] With the growing global demand for clean energy, fourth-generation advanced nuclear energy systems (such as lead-based fast reactors) have become a research hotspot. Lead-bismuth alloys, due to their high boiling point (above 1200℃), low vapor pressure, and excellent neutronics properties, are being used as the core coolant / split reaction target for lead-based fast reactors. The evaporation and migration behavior of fission products is a key aspect of nuclear safety assessment. Their characteristics in a lead-bismuth environment differ significantly from those of conventional water reactors, directly impacting the safety design and contingency planning of lead-based fast reactors.

[0003] Currently, existing research on lead-bismuth alloys mainly focuses on corrosion protection and heat transfer performance. However, specialized experimental systems for the evaporation behavior of fission products have a significant shortcoming: they cannot reproduce the actual evaporation scenario of fission products. Summary of the Invention

[0004] The purpose of this invention is to provide a test system and method for the evaporation behavior of liquid lead-bismuth environmental fission products.

[0005] A test system for the evaporation behavior of liquid lead-bismuth fission products in an environment includes a reaction vessel, a temperature control system, an atmosphere control system, a reactant storage system, and a sampling and analysis system. The reaction vessel is used to hold liquid lead-bismuth and fission products. The temperature control system includes a heating unit and a temperature monitoring unit for precise temperature control of the reaction vessel. The atmosphere control system includes an inert gas supply unit, an inert gas driving injection unit, and a pressure monitoring unit for providing a controllable gas phase environment. The reactant storage system stores iodine and cesium iodide, and the inert gas driving injection unit regulates the pressure and flow rate of the inert gas to achieve quantitative injection of iodine and cesium iodide. The sampling and analysis system includes a gas-liquid two-phase simultaneous sampling module and an analysis module for measuring the composition and particle size distribution of the evaporation products.

[0006] Furthermore, the reaction vessel module is a high-temperature resistant container with a protective layer on the inner wall and an insulation layer on the outer side.

[0007] Furthermore, the high-temperature resistant container is made of ceramic or graphite crucible, with a temperature resistance of over 1000℃; the protective layer is made of stainless steel coating, and the insulation layer is made of aluminum silicate insulation layer.

[0008] Furthermore, the bottom of the reaction vessel is designed as a hemispherical structure and is equipped with a lead-bismuth top charging pipe interface, a lead-bismuth reflux pipe interface, and an inert gas pipe interface.

[0009] Furthermore, the temperature monitoring unit uses a thermocouple as a temperature sensor, and the pressure monitoring unit uses a high-temperature resistant transmitter as a pressure sensor; the thermocouple and the high-temperature resistant transmitter are arranged along the axial direction of the reaction vessel to monitor the temperature field and pressure changes inside the reaction vessel in real time.

[0010] Furthermore, the gas-liquid two-phase synchronous sampling module includes a gas phase sampling pipeline, a liquid phase sampling pipeline, and a gas-liquid separation device. The gas phase sampling pipeline is installed in the gas space of the reaction tank, the liquid phase sampling pipeline has an adjustable sampling depth, and the gas-liquid separation device is used to separate the gas phase and liquid phase components during the sampling process. Multi-point sampling and sampling frequency control ensure the representativeness of the sample.

[0011] Furthermore, the analysis module includes a gas chromatography-mass spectrometry (GC-MS) instrument and an inductively coupled plasma mass spectrometer (ICP-MS), which are used to determine the concentrations of gas-phase fission products and liquid-phase fission products, respectively. Based on the gas-phase concentration data and temperature and pressure parameters, the saturated vapor partial pressure is calculated. Based on the changes in gas and liquid phase concentrations and the kinetic model, the evaporation rate is derived, and then the evaporation behavior of fission products under different temperature and pressure conditions is analyzed.

[0012] A method for testing the evaporation behavior of fission products in liquid lead-bismuth in an environment includes the following steps:

[0013] Step 1: Add solid lead bismuth to the reaction vessel, start the heating unit, raise the temperature to above the melting point of lead bismuth, maintain the gas phase oxygen content within the preset range through the atmosphere control system, and proceed to the next step after the temperature is stabilized.

[0014] Step 2: Set the inert gas driving pressure and flow rate through the inert gas driving injection unit, and quantitatively inject iodine and cesium iodide into the reaction vessel; promote the uniform dispersion of fission products in liquid lead bismuth through a stirring mechanism, and verify the concentration uniformity through multi-point liquid phase sampling to ensure that the concentration deviation is within the preset range.

[0015] Step 3: Starting from the initial temperature, increase the temperature stepwise according to the preset temperature gradient, and stabilize at each temperature point for a preset time; maintain the stability of each parameter through temperature-pressure-atmosphere linkage control;

[0016] Step 4: After stabilization at each temperature point, gas and liquid phase samples are taken simultaneously; gas phase samples are collected through an anti-condensation sampling tube, processed by a gas-liquid separation device, and then analyzed by a gas chromatography-mass spectrometry (GC-MS); liquid phase samples are collected through an adjustable depth sampling tube, cooled and solidified, and then analyzed by an inductively coupled plasma mass spectrometer (ICP-MS); sampling is repeated multiple times at each temperature point, and the average value is taken to ensure data representativeness.

[0017] Step 5: Calculate the saturated vapor partial pressure using a vapor partial pressure calculation model based on gas phase concentration data and temperature and pressure parameters; derive the evaporation rate using an evaporation kinetics model based on gas-liquid phase concentration change data; eliminate measurement errors using data processing algorithms, and perform data fitting and verification.

[0018] Step 6: Store temperature, pressure, gas phase concentration, liquid phase concentration, vapor partial pressure, and evaporation rate data in real time, generate evaporation kinetic curves, and analyze the evaporation behavior of fission products under different temperature and pressure conditions.

[0019] Furthermore, pretreatment is performed before the experiment: the reaction vessel is evacuated to a preset vacuum level, inert gas is introduced to a preset pressure, and the heating unit is started to preheat the reaction vessel and pipelines to a preset temperature.

[0020] Furthermore, after the experiment, the heating unit was shut down; liquid lead and bismuth were discharged into the recovery tank through the lead and bismuth recovery pipeline; after cooling to room temperature, the atmosphere control system was shut down; and the system was cleaned and decontaminated.

[0021] The beneficial effects of this invention are as follows:

[0022] This invention achieves precise control of temperature, pressure, and gaseous environment (air / argon) through modular design, enabling research on the saturated vapor partial pressure, evaporation rate, and aerosol characteristics of fission products (such as iodine and cesium). This invention can be used to study the mechanism of fission product evaporation behavior in lead-bismuth environments under accident conditions, providing experimental basis for the safety analysis and radiation protection design of lead-bismuth cooled fast reactors. It features high temperature control precision, a wide parameter adjustment range, and strong real-time data acquisition, ensuring the reliability and repeatability of experimental results. It effectively solves the problem in existing technologies of lacking dedicated experimental equipment for the evaporation characteristics of fission products in lead-bismuth environments, and the inability to accurately measure the evaporation behavior and migration patterns of fission products under high temperature and high pressure conditions. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a test system for the evaporation behavior of liquid lead-bismuth environmental fission products according to the present invention. Detailed Implementation

[0024] The present invention will now be further described with reference to the accompanying drawings.

[0025] The purpose of this invention is to provide a testing system and method for the evaporation behavior of fission products in a liquid lead-bismuth environment, addressing the problems of insufficient dedicated equipment and inability to simulate complex operating conditions in existing technologies. This invention enables precise control of temperature, pressure, and atmosphere, and provides experimental basis for the safe design of lead-bismuth coolant reactors through multi-dimensional measurement and analysis of the evaporation characteristics of fission products.

[0026] A test system for the evaporation behavior of liquid lead-bismuth environmental fission products includes a reaction vessel, a temperature control system, an atmosphere control system, a reactant storage system, and a sampling and analysis system.

[0027] The reaction vessel is used to hold liquid lead-bismuth and its fission products. The reaction vessel module is a high-temperature resistant container with a protective inner wall and an outer insulation layer. The high-temperature resistant container uses a ceramic or graphite crucible with a temperature resistance exceeding 1000℃; the protective layer is made of stainless steel, and the insulation layer is made of aluminum silicate. The bottom of the reaction vessel is designed with a hemispherical structure and is equipped with lead-bismuth top charging pipe interface, lead-bismuth return pipe interface, and inert gas pipe interface.

[0028] The temperature control system includes a heating unit and a temperature monitoring unit for precise temperature control of the reaction vessel. The atmosphere control system includes an inert gas supply unit, an inert gas driving injection unit, and a pressure monitoring unit for providing a controllable gaseous environment. The temperature monitoring unit uses thermocouples as temperature sensors, and the pressure monitoring unit uses high-temperature transmitters as pressure sensors. The thermocouples and high-temperature transmitters are arranged along the axis of the reaction vessel to monitor the temperature field and pressure changes within the vessel in real time. The reactant storage system stores iodine and cesium iodide, and the quantitative injection of iodine and cesium iodide is achieved by adjusting the inert gas pressure and flow rate through the inert gas driving injection unit.

[0029] The sampling and analysis system includes a gas-liquid two-phase simultaneous sampling module and an analysis module, used to measure the composition and particle size distribution of evaporation products. The gas-liquid two-phase simultaneous sampling module includes a gas phase sampling pipeline, a liquid phase sampling pipeline, and a gas-liquid separation device. The gas phase sampling pipeline is located in the gas space of the reaction vessel, the liquid phase sampling pipeline has adjustable sampling depth, and the gas-liquid separation device is used to separate the gas and liquid phase components during the sampling process. Multi-point sampling and sampling frequency control ensure sample representativeness. The analysis module includes a gas chromatography-mass spectrometry (GC-MS) instrument and an inductively coupled plasma mass spectrometer (ICP-MS), used to determine the concentrations of gas-phase and liquid-phase fission products, respectively. Based on the gas phase concentration data and temperature and pressure parameters, the saturated vapor partial pressure is calculated. Based on the changes in gas and liquid phase concentrations and a kinetic model, the evaporation rate is derived, and the evaporation behavior of fission products under different temperature and pressure conditions is analyzed.

[0030] A method for testing the evaporation behavior of fission products in liquid lead-bismuth in an environment includes the following steps:

[0031] Step 1, System Pretreatment Steps: Evacuate the reaction vessel to the preset vacuum level, fill it with inert gas to the preset pressure, start the heating unit, and preheat the reaction vessel and pipelines to the preset temperature.

[0032] Step 2, lead-bismuth melting step: Add solid lead-bismuth to the reaction vessel, start the heating unit, raise the temperature to above the melting point of lead-bismuth, maintain the gas phase oxygen content within the preset range through the atmosphere control system, and proceed to the next step after the temperature is stabilized.

[0033] Step 3, quantitative injection of fission products: Iodine and cesium iodide are quantitatively injected into the reaction vessel by setting the inert gas driving pressure and flow rate through the inert gas driven injection unit; the uniform dispersion of fission products in liquid lead bismuth is promoted by the stirring mechanism; the concentration uniformity is verified by multi-point liquid phase sampling to ensure that the concentration deviation is within the preset range.

[0034] Step 4, Stepwise heating evaporation step: Starting from the initial temperature, the temperature is increased stepwise according to the preset temperature gradient, and the temperature is stabilized for a preset time at each temperature point; the stability of each parameter is maintained through temperature-pressure-atmosphere linkage control.

[0035] Step 5, simultaneous gas-liquid two-phase sampling: After stabilization at each temperature point, gas and liquid phase samples are simultaneously sampled; gas phase samples are collected through an anti-condensation sampling tube, processed by a gas-liquid separation device, and then analyzed by a gas chromatography-mass spectrometry (GC-MS); liquid phase samples are collected through an adjustable depth sampling tube, cooled and solidified, and then analyzed by an inductively coupled plasma mass spectrometer (ICP-MS); sampling is repeated multiple times at each temperature point, and the average value is taken to ensure data representativeness.

[0036] Step 6, Evaporation kinetic parameter calculation steps: Based on gas phase concentration data and temperature and pressure parameters, calculate the saturated vapor partial pressure using a vapor partial pressure calculation model; based on gas-liquid phase concentration change data, derive the evaporation rate using an evaporation kinetic model; eliminate measurement errors using data processing algorithms, and perform data fitting and verification;

[0037] Step 7, Data Recording and Analysis: Real-time storage of temperature, pressure, gas phase concentration, liquid phase concentration, vapor partial pressure, and evaporation rate data; generation of evaporation kinetic curves; and analysis of the evaporation behavior of fission products under different temperature and pressure conditions.

[0038] Step 8, System Recovery Steps: After the test, turn off the heating unit; discharge liquid lead and bismuth into the recovery tank through the lead and bismuth recovery pipeline; after cooling to room temperature, turn off the atmosphere control system; clean and decontaminate the system.

[0039] Example 1:

[0040] like Figure 1As shown in the figure, this embodiment provides a test system for the evaporation behavior of liquid lead-bismuth environmental fission products, including a reaction vessel system, a high-temperature heating system, a feeding and gas supply system, a pressure stabilization system, an evaporation and collection system, a gas-liquid sampling system, a measurement and data acquisition system, and a lead-bismuth recovery system. The reference numerals in the figure include: 1. Pressure stabilization system; 2. Air pump; 3. Gas storage tank; 4. Argon cylinder; 5. Pressure reducing valve; 6. Argon master tank; 7. Iodine and cesium iodide storage tank; 8. Reaction vessel; 9. Water washing container; 10. Gas phase sampling pipeline of the water washing container.

[0041] The reaction vessel is a critical component, employing a ceramic or graphite crucible as the high-temperature reaction container, with a temperature resistance exceeding 1000℃. The inner layer is made of 316L stainless steel, while the outer layer is wrapped with an aluminum silicate insulation layer. The bottom of the vessel is designed with a hemispherical structure and is equipped with lead-bismuth top-fill / back-flow pipe flanges and argon gas inlet and outlet interfaces. Temperature sensors (K-type thermocouples) and pressure sensors (PT3003 high-temperature transmitters) are arranged along the vessel's axis to monitor the temperature field and pressure changes within the reaction vessel in real time.

[0042] The temperature control and heating system consists of a high-temperature furnace and zoned heat tracing modules. The heat tracing system uses electric heat tracing wires to cover the reaction vessel, pipelines, and sampling circuits, effectively preventing lead and bismuth from solidifying. A PLC system enables closed-loop temperature control, supporting heating or constant temperature control within a range of 1000℃.

[0043] The atmosphere control system includes an argon gas supply subsystem and an air / argon gas switching subsystem. Argon gas, after being pressurized in a mother tank, is injected into the reaction vessel via a mass flow controller to maintain an inert environment. Air, after being dried and filtered, is used to simulate an oxidizing atmosphere. The system is equipped with an online oxygen content monitor to ensure atmosphere purity.

[0044] The sampling and analysis system includes gas phase and liquid phase sampling, as well as aerosol measurement. Gas phase sampling is performed by connecting a condenser and a gas chromatography-mass spectrometry (GC-MS) system via a gas space sampling pipeline to collect evaporated fission products. Liquid phase sampling uses a quartz sampling tube to collect samples from the lead-bismuth melt, and the concentration of fission products is analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Aerosol measurement is performed using an SMPS aerosol particle size analyzer to monitor the aerosol particle size distribution in the gas space in real time.

[0045] The data acquisition and control system uses an NI 24-bit data acquisition board to simultaneously acquire parameters such as temperature, pressure, and flow rate. It uses LabVIEW software to realize real-time data storage, visualization, and remote control, supporting the automated execution of experimental conditions.

[0046] During system preparation, high-purity lead-bismuth alloy was first precisely added to the reaction vessel. Then, the cover was closed, and a vacuum pump was used to evacuate the vessel, ensuring a low-pressure environment inside. Next, argon gas was introduced to the required pressure to prevent oxidation. Simultaneously, the heating system was activated to preheat the piping, preparing for subsequent experimental operations.

[0047] Regarding the operating conditions, based on experimental requirements, the temperature range of the reaction vessel was set within 1000℃, and the pressure was set between 0.8 and 1.2 atm. A suitable carrier gas type, such as argon or air, was selected. The high-temperature furnace was automatically started via a PLC (Programmable Logic Controller) for heating. During the fission product injection stage, argon was used as the driving medium to quantitatively inject high-purity iodine / cesium iodide reagent into the reaction vessel. After injection, the mixture was stirred to ensure thorough mixing of the reagent and the lead-bismuth alloy. Subsequently, the reaction vessel was allowed to stand to allow the chemical reaction to proceed fully.

[0048] During the sampling and analysis phase, after the temperature inside the reaction vessel stabilized, samples were collected periodically. The collected samples included both gas and liquid phases. The vapor partial pressure was determined using GC-MS (gas chromatography-mass spectrometry), and the concentration in the liquid phase was analyzed using ICP-MS (inductively coupled plasma mass spectrometry). The evaporation rate was calculated using these data.

[0049] After the experiment, the system recovery phase began. First, the heating system was shut down. Then, by adjusting the argon pressure, the reacted lead-bismuth alloy was recovered into the storage tank. After cooling to room temperature, the system was cleaned to prepare for the next experiment. Through these steps, the experiment not only obtained accurate experimental data but also ensured the stable operation of the system, thus achieving the expected beneficial results.

[0050] In this embodiment, fission products are introduced into the reaction vessel via a feeding and gas supply system. The fission products, stored in corresponding storage tanks as iodine or cesium iodide, enter the reaction vessel under the action of argon carrier gas, ensuring full contact with the liquid lead bismuth. A pressure stabilization system continuously adjusts the pressure within the reaction vessel, maintaining it within a set range. After evaporation from the liquid lead bismuth, the fission products enter the gas phase space and are then condensed or adsorbed by an evaporation and collection system. The collected samples are analyzed using a measurement and data acquisition system to obtain data on the concentration, chemical speciation, and evaporation characteristics of the fission products.

[0051] In this embodiment, the core experimental container is made of 316L stainless steel, combined with an aluminum silicate insulation layer and an electric heating system, which can ensure the fluidity and oxidation resistance of the lead-bismuth medium at high temperatures; the pressure is regulated by an argon gas supply system, thereby controlling the lead-bismuth liquid level and maintaining an inert environment; the measurement system integrates a high-precision temperature sensor, a pressure transmitter, and a gas chromatography-mass spectrometry device, combined with PLC automation control and a LabVIEW data acquisition platform, to achieve real-time monitoring of multiple parameters and data visualization.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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. A test system for the evaporation behavior of fission products in a liquid lead-bismuth environment, characterized in that: This includes reaction vessels, temperature control systems, atmosphere control systems, reactant storage systems, and sampling and analysis systems. The reaction vessel is used to hold liquid lead-bismuth and fission products; The temperature control system includes a heating unit and a temperature monitoring unit, which are used to achieve precise control of the reaction vessel temperature; The atmosphere control system includes an inert gas supply unit, an inert gas driving injection unit, and a pressure monitoring unit, which are used to provide a controllable gas phase environment. The reactant storage system is used to store iodine and cesium iodide, and the quantitative injection of iodine and cesium iodide is achieved by adjusting the pressure and flow rate of the inert gas through the inert gas driven injection unit. The sampling and analysis system includes a gas-liquid two-phase simultaneous sampling module and an analysis module, which are used to measure the composition and particle size distribution of evaporation products.

2. The experimental system for testing the evaporation behavior of liquid lead-bismuth environmental fission products according to claim 1, characterized in that: The reaction vessel module is a high-temperature resistant container with a protective layer on the inner wall and an insulation layer on the outer side.

3. The experimental system for testing the evaporation behavior of liquid lead-bismuth environmental fission products according to claim 2, characterized in that: The high-temperature resistant container is made of ceramic or graphite crucible, with a temperature resistance of over 1000℃; the protective layer is made of stainless steel coating, and the insulation layer is made of aluminum silicate insulation layer.

4. The experimental system for testing the evaporation behavior of liquid lead-bismuth environmental fission products according to claim 1, characterized in that: The bottom of the reaction vessel is designed with a hemispherical structure and is equipped with a lead-bismuth top charging pipe interface, a lead-bismuth reflux pipe interface, and an inert gas pipe interface.

5. The experimental system for testing the evaporation behavior of liquid lead-bismuth environmental fission products according to claim 1, characterized in that: The temperature monitoring unit uses a thermocouple as a temperature sensor, and the pressure monitoring unit uses a high-temperature transmitter as a pressure sensor; the thermocouple and the high-temperature transmitter are arranged along the axis of the reaction vessel to monitor the temperature field and pressure changes inside the reaction vessel in real time.

6. The experimental system for testing the evaporation behavior of liquid lead-bismuth environmental fission products according to claim 1, characterized in that: The gas-liquid two-phase synchronous sampling module includes a gas phase sampling pipeline, a liquid phase sampling pipeline, and a gas-liquid separation device. The gas phase sampling pipeline is located in the gas space of the reaction tank, the liquid phase sampling pipeline has an adjustable sampling depth, and the gas-liquid separation device is used to separate the gas phase and liquid phase components during the sampling process. Multi-point sampling and sampling frequency control ensure the representativeness of the sample.

7. The experimental system for testing the evaporation behavior of liquid lead-bismuth environmental fission products according to claim 1, characterized in that: The analysis module includes a gas chromatography-mass spectrometry (GC-MS) instrument and an inductively coupled plasma mass spectrometer (ICP-MS), which are used to determine the concentrations of gas-phase fission products and liquid-phase fission products, respectively. Based on the gas-phase concentration data and temperature and pressure parameters, the saturated vapor partial pressure is calculated. Based on the changes in gas and liquid phase concentrations and the kinetic model, the evaporation rate is derived, and then the evaporation behavior of fission products under different temperature and pressure conditions is analyzed.

8. A test method based on the test system for the evaporation behavior of liquid lead-bismuth environmental fission products as described in claim 1, characterized in that, Includes the following steps: Step 1: Add solid lead bismuth to the reaction vessel, start the heating unit, raise the temperature to above the melting point of lead bismuth, maintain the gas phase oxygen content within the preset range through the atmosphere control system, and proceed to the next step after the temperature is stabilized. Step 2: Set the inert gas driving pressure and flow rate through the inert gas driving injection unit, and quantitatively inject iodine and cesium iodide into the reaction vessel; promote the uniform dispersion of fission products in liquid lead bismuth through a stirring mechanism, and verify the concentration uniformity through multi-point liquid phase sampling to ensure that the concentration deviation is within the preset range. Step 3: Starting from the initial temperature, increase the temperature stepwise according to the preset temperature gradient, and stabilize at each temperature point for a preset time; maintain the stability of each parameter through temperature-pressure-atmosphere linkage control; Step 4: After stabilization at each temperature point, gas and liquid phase samples are taken simultaneously; gas phase samples are collected through an anti-condensation sampling tube, processed by a gas-liquid separation device, and then analyzed by a gas chromatography-mass spectrometry (GC-MS); liquid phase samples are collected through an adjustable depth sampling tube, cooled and solidified, and then analyzed by an inductively coupled plasma mass spectrometer (ICP-MS); sampling is repeated multiple times at each temperature point, and the average value is taken to ensure data representativeness. Step 5: Calculate the saturated vapor partial pressure using a vapor partial pressure calculation model based on gas phase concentration data and temperature and pressure parameters; derive the evaporation rate using an evaporation kinetics model based on gas-liquid phase concentration change data; eliminate measurement errors using data processing algorithms, and perform data fitting and verification. Step 6: Store temperature, pressure, gas phase concentration, liquid phase concentration, vapor partial pressure, and evaporation rate data in real time, generate evaporation kinetic curves, and analyze the evaporation behavior of fission products under different temperature and pressure conditions.

9. The method for testing the evaporation behavior of fission products in liquid lead-bismuth in an environment according to claim 8, characterized in that: Before the experiment, pretreatment was performed, the reaction vessel was evacuated to the preset vacuum level, inert gas was introduced to the preset pressure, and the heating unit was started to preheat the reaction vessel and pipeline to the preset temperature.

10. The method for testing the evaporation behavior of fission products in a liquid lead-bismuth environment according to claim 8, characterized in that: After the experiment, the heating unit was turned off; liquid lead and bismuth were discharged into the recovery tank through the lead and bismuth recovery pipeline; after cooling to room temperature, the atmosphere control system was turned off; and the system was cleaned and decontaminated.

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