Device and method for measuring migration parameters of fission products in lead-bismuth replacement fluid

Abstract

The invention discloses a device and method for measuring migration parameters of fission products in a lead-bismuth substitute fluid, a device main body is composed of a visual shell and a sealing cover which are connected through a bolt, the upper part of the shell is provided with an air inlet pipe and an air outlet pipe, and the bottom of the shell is provided with a liquid outlet; a gas injection opening is formed in one side edge of the lower portion of the shell and is composed of a reference opening, a sealing gasket, a crevasse gasket, a sealing flange, a sealing bolt and a gas injection pipe connected with the crevasse gasket, wherein the reference opening, the sealing gasket, the crevasse gasket, the sealing flange and the sealing bolt are arranged on the shell. The gas inlet pipe is used for filling aerosol into the device to replace fission products, the gas outlet pipe is used for guiding out gas for measurement, and the liquid outlet is used for discharging alternative fluid; the sealing flange and the sealing bolt are used for fixing the sealing crevasse gasket and the sealing gasket to prevent the alternative fluid from leaking; and gas injection ports with different sizes and shapes can be replaced by the crevasse gasket and the gas injection pipe according to requirements, so that experiments under different working conditions can be completed. The device provided by the invention can measure aerosol migration morphological parameters and aerosol washing parameters in the visual alternative fluid, and can measure parameters in the gas and aerosol migration process under different flows, different crevasse sizes and morphologies according to requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of visualization of gas migration in liquid, and in particular relates to a device and method for measuring migration parameters of fission products in a lead-bismuth substitution fluid. Background Art

[0002] The fuel assembly of the core will produce a large amount of radioactive fission products when the reactor is running. However, the fuel rod cladding may be damaged and cracked for some reasons, thereby releasing fission products into the coolant. In addition to the common fission gases, the fission products released from the rupture also include solid fission products and liquid fission products. In the prior art, liquid and solid fission products are generally simulated uniformly with aerosol particles. At present, in the process of conducting the source term analysis of the lead-bismuth reactor mechanism, the aerosol fraction adopts 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 migration of fission products of the lead-bismuth fast reactor in the liquid lead-bismuth alloy coolant to obtain the key parameters of the fission product migration process, such as gas dynamic parameters and aerosol removal factors during the migration process, to provide support for model development and source term analysis calculations. Summary of the invention

[0003] In order to solve the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a device and method for measuring the migration parameters of fission products in a lead-bismuth substitute fluid, which can be used to study the migration and washing characteristics of gases and aerosols in liquid lead-bismuth substitute fluids with different rupture sizes and morphologies.

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

[0005] A device for measuring the migration parameters of fission products in a lead-bismuth substitution fluid, the device comprising a housing 1, a sealing cover 2, an air inlet pipe 3, an exhaust pipe 4, a liquid discharge pipe 5, a connecting bolt 1 6, a reference opening 7, a sealing gasket 8, a breach gasket 9, a sealing flange 10, a connecting bolt 2 11 and a nozzle 12;

[0006] The housing 1 is used as the main experimental site to carry the substitute fluid of the liquid lead-bismuth coolant of the lead-bismuth reactor;

[0007] The sealing cover 2 is placed above the housing 1 and connected to the housing 1 via a connecting bolt 6 to form a sealed space.

[0008] The air inlet pipe 3 is connected to the housing 1 through the air inlet at the upper part of the housing, is located outside the housing 1, and is used to directly introduce the experimental gas into the device for replacing air or pressurizing;

[0009] The exhaust pipe 4 is connected to the housing 1 through the exhaust port on the upper part of the housing, and is located outside the housing 1. It is used to discharge the gas in the device to the external environment in time when in use to ensure that the device is always under a constant pressure. At the same time, it serves as a sampling port to absorb the aerosol after the replacement fluid is passed through, and measure the particle concentration of the experimental aerosol after washing;

[0010] The drain pipe 5 is connected to the housing 1 through the drain port at the bottom of the housing, is located outside the housing 1, and is used to discharge the replacement fluid in the device;

[0011] The connecting bolts 6 are located at the periphery of the sealing cover and are evenly arranged, and connect and fasten the housing 1 and the sealing cover 2 through the screw holes on the housing 1 and the sealing cover 2;

[0012] The reference opening 7 is a square opening of a specified size processed at a specified position of the shell, and is located at the lower end of one side of the shell;

[0013] The sealing gasket 8 has the same inner dimensions as the reference opening 7, plays a sealing role to prevent liquid leakage, is located between the breach gasket and the housing 1, and is provided with a fastening screw hole;

[0014] The breach gasket 9 is a metal sheet with the same size as the sealing gasket 8, used for processing breaches of different shapes and sizes, located between the sealing flange and the sealing gasket 8, and provided with fastening screw holes;

[0015] The sealing flange 10 is used to fix the breach gasket and the sealing gasket 8 and play a sealing role, and is provided with fastening screw holes;

[0016] The connecting bolt 2 11 is used to connect the sealing flange 10, the breach gasket 9 and the sealing gasket 8 to the housing in sequence and play a tightening role;

[0017] The nozzle 12 is connected to the breach gasket 9. The shape and size of the breach gasket 9 are changed by replacing the nozzle 12 to simulate the breach of the lead-bismuth pile fuel, so as to inject aerosol into the device to replace the fission products.

[0018] The housing 1 and the sealing cover 2 are made of visible materials, which is convenient for photographing the aerosol migration morphology in the replacement fluid.

[0019] The sealing gasket 8 and the sealing flange 10 are annular squares with a certain thickness, and their inner dimensions are the same as the reference opening 7 . The size of the breach gasket 9 is the same as the outer dimensions of the sealing gasket 8 and the sealing flange 10 .

[0020] The breach gasket 9 and the nozzle 12 are processed separately and then connected into a whole.

[0021] Technical problems and advantages solved by the present invention:

[0022] Technical problems solved by the present invention:

[0023] 1. The device of the present invention solves the problem that it is difficult to visualize and measure the release and migration of fission products in a lead-bismuth pile; 2. The device of the present invention has the ability to measure the particle concentration of fission products after passing through a replacement fluid, solving the problem that it is difficult to determine the proportion of fission products in a lead-bismuth pile after being released into a lead-bismuth coolant;

[0024] 3. The device of the present invention solves the problem of difficulty in determining the rupture change in the lead-bismuth pile fission product release experiment by designing a replaceable nozzle.

[0025] The present invention has the following advantages and beneficial effects:

[0026] 1. The main body of the device of the present invention is made of visual materials, which is convenient for parameter observation during use.

[0027] 2. The device of the present invention is easy to disassemble and replace, and can more easily meet the requirements of different working conditions.

[0028] 3. 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 It is a schematic diagram of the device structure of the present invention.

[0031] 1-housing, 2-sealing cover, 3-inlet pipe, 4-exhaust pipe, 5-drain pipe, 6-connecting bolt 1, 7-reference opening, 8-sealing gasket, 9-break gasket, 10-sealing flange, 11-connecting bolt 2, 12-nozzle. DETAILED DESCRIPTION

[0032] 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.

[0033] like Figure 1 As shown, the present invention is a device for measuring the migration parameters of fission products in a lead-bismuth substitution fluid, the device comprising a housing 1, a sealing cover 2, an air inlet pipe 3, an exhaust pipe 4, a liquid discharge pipe 5, a connecting bolt 1 6, a reference opening 7, a sealing gasket 8, a breach gasket 9, a sealing flange 10, a connecting bolt 2 11 and a nozzle 12;

[0034] The housing 1 is used as the main experimental site to carry the substitute fluid of the liquid lead-bismuth coolant of the lead-bismuth reactor;

[0035] The sealing cover 2 is placed above the housing 1 and connected to the housing 1 via a connecting bolt 6 to form a sealed space.

[0036] The air inlet pipe 3 is connected to the housing 1 through the air inlet at the upper part of the housing, is located outside the housing 1, and is used to directly introduce the experimental gas into the device for replacing air or pressurizing;

[0037] The exhaust pipe 4 is connected to the housing 1 through the exhaust port on the upper part of the housing, and is located outside the housing 1. It is used to discharge the gas in the device to the external environment in time when in use to ensure that the device is always under a constant pressure. At the same time, it serves as a sampling port to absorb the aerosol after the replacement fluid is passed through, and measure the particle concentration of the experimental aerosol after washing;

[0038] The drain pipe 5 is connected to the housing 1 through the drain port at the bottom of the housing, is located outside the housing 1, and is used to discharge the replacement fluid in the device;

[0039] The connecting bolts 6 are located at the periphery of the sealing cover and are evenly arranged, and connect and fasten the housing 1 and the sealing cover 2 through the screw holes on the housing 1 and the sealing cover 2;

[0040] The reference opening 7 is a square opening of a specified size processed at a specified position of the shell, and is located at the lower end of one side of the shell;

[0041] The sealing gasket 8 has the same inner dimensions as the reference opening 7, plays a sealing role to prevent liquid leakage, is located between the breach gasket and the housing 1, and is provided with a fastening screw hole;

[0042] The breach gasket 9 is a metal sheet with the same size as the sealing gasket 8, used for processing breaches of different shapes and sizes, located between the sealing flange and the sealing gasket 8, and provided with fastening screw holes;

[0043] The sealing flange 10 is used to fix the breach gasket and the sealing gasket 8 and play a sealing role, and is provided with fastening screw holes;

[0044] The connecting bolt 2 11 is used to connect the sealing flange 10, the breach gasket 9 and the sealing gasket 8 to the housing in sequence and play a tightening role;

[0045] The nozzle 12 is connected to the breach gasket 9. The shape and size of the breach gasket 9 are changed by replacing the nozzle 12 to simulate the breach of the lead-bismuth pile fuel, so as to inject aerosol into the device to replace the fission products.

[0046] Preferably, the housing 1 and the sealing cover 2 are made of a visible material to facilitate photographing the aerosol migration morphology in the replacement fluid.

[0047] Preferably, the sealing gasket 8 and the sealing flange 10 are annular squares with a certain thickness, and their inner dimensions are the same as the reference opening 7, and the size of the breach gasket 9 is the same as the outer dimensions of the sealing gasket 8 and the sealing flange 10. This design can ensure that there is enough space for the breach gasket to construct breaches of different sizes and shapes, and at the same time can ensure sealing to prevent liquid leakage.

[0048] The breach gasket 9 and the nozzle 12 are connected as a whole after being processed separately, which reduces the number of installation parts and can effectively enhance the sealing performance here.

[0049] The method for using the device for measuring the migration parameters of fission products in the lead-bismuth substitution fluid comprises the following steps:

[0050] First, assemble the sealing gasket 8, the breach gasket 9 and the sealing flange 10 according to the selected working conditions, seal the sealing cover 2, and ensure that each joint is well sealed and has no obvious damage or leakage;

[0051] After the assembly is completed, liquid lead-bismuth coolant is added to the device to replace the fluid to the specified height, the air inlet pipe 3 and the exhaust pipe 4 are closed to seal the entire device, and the device is left to stand for a preset time to observe whether there is liquid leakage in various parts of the device. If there is, the sealing device needs to be reassembled; if not, it means that the device has good sealing performance and meets subsequent requirements;

[0052] Open the air inlet pipe 3 and the exhaust pipe 4, inject the experimental gas into the device, and after all the air in the gas area is replaced by the experimental gas, close the air inlet pipe 3 and the exhaust pipe 4; use an external gas injection device to inject an aerosol with a known particle concentration into the liquid in the device through the nozzle 12 and the rupture gasket 9 to replace the fission products, and at the same time open the exhaust pipe 4 to exhaust the gas outward; during the gas injection process, it is necessary to pay attention to the pressure in the device at all times. If there is a significant increase, it is necessary to open more exhaust pipes 4 for exhaust; at the same time, it is necessary to measure the aerosol parameters during the gas injection stage, and the aerosol migration morphology in the replacement fluid is photographed by an external high-speed camera, and the particle concentration of the washed gas is absorbed by the exhaust pipe 4 into the external particle size spectrometer for measurement. The release share of the fission products after passing through the replacement fluid is calculated based on the initial aerosol particle concentration. The measurement of the two fission product migration parameters, gas morphology and fission product release share, is completed through the above measurement;

[0053] After the gas injection stage is completed, record and organize the data and turn off the measuring equipment; drain the liquid in the device through the drain port 5, open all the air inlet pipes 3 and exhaust pipes 4, open the sealing cover 2, add deionized water to the device for cleaning, and after cleaning, remove the sealing flange 10, the breach gasket 9 and the sealing gasket 8, and wait for the entire device to dry.

[0054] 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 migration parameters of fission products in a lead-bismuth substitution fluid, Features: The device comprises a housing (1), a sealing cover (2), an air inlet pipe (3), an exhaust pipe (4), a liquid discharge pipe (5), a first connecting bolt (6), a reference opening (7), a sealing gasket (8), a breach gasket (9), a sealing flange (10), a second connecting bolt (11) and a nozzle (12); The housing (1) is used as the main experimental site and is used to carry the substitute fluid of the liquid lead-bismuth coolant of the lead-bismuth reactor; The sealing cover (2) is placed above the outer shell (1) and connected to the outer shell (1) via a connecting bolt (6) to form a sealed space. The air inlet pipe (3) is connected to the outer shell (1) through an air inlet port at the upper part of the outer shell, is located outside the outer shell (1), and is used to directly introduce experimental gas into the device for replacing air or increasing pressure; The exhaust pipe (4) is connected to the housing (1) via an exhaust port at the upper portion of the housing, is located outside the housing (1), and is used to timely exhaust the gas in the device to the external environment when in use to ensure that the pressure in the device is always constant, and is also used as a sampling port to absorb the aerosol after the replacement fluid is passed through, so as to measure the particle concentration of the experimental aerosol after washing; The drain pipe (5) is connected to the housing (1) via a drain port at the bottom of the housing, is located outside the housing (1), and is used to discharge the replacement fluid in the device; The connecting bolts (6) are located on the periphery of the sealing cover and are evenly arranged, and are connected and fastened to the housing (1) and the sealing cover (2) through screw holes on the housing (1) and the sealing cover (2); The reference opening (7) is a square opening of a specified size processed at a specified position of the shell, and is located at the lower end of one side of the shell; The sealing gasket (8) is a gasket with the same inner dimensions as the reference opening (7), which plays a sealing role to prevent liquid leakage, is located between the breach gasket and the housing (1), and is provided with a fastening screw hole; The breach gasket (9) is a metal sheet having the same size as the sealing gasket (8) and is used for processing breaches of different shapes and sizes. It is located between the sealing flange and the sealing gasket (8) and is provided with a fastening screw hole. The sealing flange (10) is used to fix the breach gasket and the sealing gasket (8) and play a sealing role, and is provided with fastening screw holes; The second connecting bolt (11) is used to connect the sealing flange (10), the breach gasket (9) and the sealing gasket (8) to the housing in sequence and plays a tightening role; The nozzle (12) is connected to the breach gasket (9), and the shape and size of the breach gasket (9) are changed by replacing the nozzle (12) to simulate the breach of the lead-bismuth pile fuel, so as to inject aerosol into the device to replace the fission product.

2. The device for measuring the migration parameters of fission products in a lead-bismuth substitution fluid according to claim 1, It is characterized in that The housing (1) and the sealing cover (2) are made of visible materials, which facilitates photographing the aerosol migration morphology in the replacement fluid.

3. The device for measuring the migration parameters of fission products in a lead-bismuth substitution fluid according to claim 1, It is characterized in that The sealing gasket (8) and the sealing flange (10) are annular squares with a certain thickness, and their inner dimensions are the same as the reference opening (7). The size of the breach gasket (9) is the same as the outer dimensions of the sealing gasket (8) and the sealing flange (10).

4. The device for measuring the migration parameters of fission products in a lead-bismuth substitution fluid according to claim 1, It is characterized in that The breach gasket (9) and the nozzle (12) are processed separately and then connected into a whole.

5. A method for using the device for measuring the migration parameters of fission products in a lead-bismuth substitution fluid as claimed in any one of claims 1 to 4, It is characterized in that The method comprises the following steps: First, assemble the sealing gasket (8), the breach gasket (9) and the sealing flange (10) according to the selected working conditions, seal the sealing cover (2), and ensure that all joints are well sealed and have no obvious damage or leakage; After the assembly is completed, liquid lead-bismuth coolant is added to the device to replace the fluid to a specified height, the air inlet pipe (3) and the exhaust pipe (4) are closed to seal the entire device, and the device is left to stand for a preset time to observe whether there is liquid leakage in various parts of the device. If there is, the sealing device needs to be reassembled; if not, it means that the device has good sealing performance and meets subsequent requirements; The air inlet pipe (3) and the exhaust pipe (4) are opened, and the experimental gas is injected into the device. After all the air in the gas area is replaced by the experimental gas, the air inlet pipe (3) and the exhaust pipe (4) are closed; an external air injection device is used to inject an aerosol with a known particle concentration into the liquid in the device through a nozzle (12) and a rupture gasket (9) to replace the fission product, and the exhaust pipe (4) is opened to exhaust the gas outward; during the air injection process, it is necessary to pay attention to the pressure in the device at all times. If there is a significant increase, more exhaust pipes (4) need to be opened for exhaust; at the same time, the aerosol parameters need to be measured during the air injection stage, and the aerosol migration morphology in the replacement fluid is photographed by an external high-speed camera. The particle concentration of the washed gas is measured by absorbing the gas through the exhaust pipe (4) into an external particle size spectrometer, and the release fraction of the fission product after passing through the replacement fluid is calculated based on the initial aerosol particle concentration. The measurement of the two fission product migration parameters, gas morphology and fission product release fraction, is completed through the above measurement; After the gas injection phase is completed, the data is recorded and organized, and the measuring equipment is turned off; the liquid in the device is discharged through the drain port (5), all the air inlet pipes (3) and the exhaust pipes (4) are opened, the sealing cover (2) is opened, and deionized water is added to the device for cleaning. After the cleaning is completed, the sealing flange (10), the breach gasket (9) and the sealing gasket (8) are removed, and the entire device is allowed to dry.

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