Electrostatic collection and monitoring of airborne effluents from nuclear facilities

Abstract

The utility model is suitable for nuclear power detection field, disclose a kind of nuclear facility airborne effluent electrostatic collection and monitoring device, comprising: the sampling tube being arranged in nuclear facility chimney, the ionization unit for ionizing aerosol particle transmission of the sampling tube being connected with the sampling tube, electrode adsorption unit for adsorbing aerosol particle after ionization, high purity germanium detector being arranged in the electrode adsorption unit and being used to detect nuclide;By setting first optical aerosol particle size spectrometer in the sampling tube close to nuclear facility chimney, then the other end of sampling tube is provided with second optical aerosol particle size spectrometer, the proportion of aerosol particle mass at the both ends of sampling tube is compared, the proportion of aerosol particle loss in sampling tube is obtained, then after nuclide detection and the collection of aerosol particle containing strontium-90, it is detected and corrected according to proportion, and the actual discharge capacity can be accurately obtained.

Description

Technical Field

[0001] This utility model relates to the field of nuclear power plant detection, and in particular to an electrostatic collection and monitoring device for gaseous effluent from nuclear facilities. Background Technology

[0002] During normal operation, abnormal operation, and nuclear accidents, nuclear facilities release gaseous radioactive effluents into the atmosphere through chimneys. These effluents contain radioactive suspended particles with diameters ranging from 0.01 micrometers to tens of micrometers. When released into the environment, these particles can be inhaled and remain in the body, causing internal radiation exposure and resulting in radiation damage. Therefore, the sampling and measurement of radioactive aerosols is an important research area in the fields of radiation protection and environmental monitoring.

[0003] The penetration efficiency of radioactive aerosols in nuclear facility chimneys is a key indicator of sample representativeness. During transport in the sampling and transmission system, aerosol particles experience deposition losses on the inner surface of the transmission pipes due to various factors such as gravitational settling, inertial collisions, and turbulence, resulting in reduced penetration efficiency. The "Technical Specification for Radioactive Monitoring of Effluents from Nuclear Facilities" requires that "the collection efficiency of airborne effluent samples must be strictly calibrated. For airborne effluent sampling, the pipe deposition rate of aerosols and iodine sampling should be verified and used to correct the collection efficiency." It also stipulates that nuclear facilities must conduct monitoring of gamma nuclides and strontium-90 in radioactive aerosols. HJ 61-2021, the "Technical Specification for Radiation Environment Monitoring," requires that radiation environment monitoring during nuclear power plant operation, low- and intermediate-level radioactive waste disposal sites, and nuclear fuel reprocessing facilities all include monitoring of gamma nuclides and strontium-90 in radioactive aerosols. The sampling volume of airborne effluents from nuclear facilities must be corrected for aerosol pipe deposition losses; otherwise, it will lead to a significant underestimation of actual emissions.

[0004] Existing technologies generally rely on theoretical calculations or model experiments, rather than direct sampling in nuclear facility systems, leading to significant discrepancies between test results and actual conditions. Current technologies employ high-powered fans and filter membranes to collect aerosols; however, the accumulation of aerosol particles on the filter membrane generates substantial air resistance, resulting in high energy consumption and unstable sampling flow rates. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an electrostatic collection and monitoring device for gaseous effluent from nuclear facilities.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: A device for electrostatic collection and monitoring of gaseous effluent from a nuclear facility is constructed, comprising: a sampling tube installed inside the nuclear facility chimney; an ionization unit connected to the sampling tube for ionizing aerosol particles transported by the sampling tube; an electrode adsorption unit for adsorbing ionized aerosol particles; and a high-purity germanium detector installed inside the electrode adsorption unit for detecting nuclides. The sampling tube is equipped with a first optical aerosol particle size spectrometer for detecting the mass of aerosol particles at one end near the nuclear facility chimney, and a second optical aerosol particle size spectrometer for detecting the mass of aerosol particles at the other end near the ionization unit.

[0007] Furthermore, a first switching valve is provided at the connection between the first optical aerosol particle size spectrometer and the sampling tube, and a second switching valve is provided at the connection between the second optical aerosol particle size spectrometer and the sampling tube.

[0008] Furthermore, the electrode adsorption unit is provided with a sealed cylinder, the ionization unit is disposed inside the sealed cylinder, and the end of the ionization unit away from the sampling tube abuts against the electrode adsorption unit.

[0009] Furthermore, the electrode adsorption unit includes several electrode wires for adsorbing aerosol particles and several collection filter papers for collecting aerosol particles.

[0010] Furthermore, each layer of the collecting filter paper is arranged around the high-purity germanium detector, and the collecting filter paper is perpendicular to the airflow direction inside the sealed cylinder.

[0011] Furthermore, the end of the sealing cylinder away from the ionization unit is provided with a sealing cap that is detachably connected to the sealing cylinder.

[0012] Furthermore, the sealing cap is equipped with a filtration pump for drawing in and filtering the air inside the sealing cylinder.

[0013] Furthermore, a first flow meter for detecting the flow rate of the sampling tube is provided at the end of the sampling tube closest to the nuclear facility chimney.

[0014] Furthermore, the high-purity germanium detector is equipped with a second flow meter for detecting the flow rate of the outgoing gas.

[0015] Furthermore, the ionization unit is provided with a high-voltage power supply for providing high-voltage current to the ionization unit and the electrode adsorption unit, the high-voltage power supply providing a voltage range of 5 kV to 20 kV.

[0016] The present invention provides an electrostatic collection and monitoring device for airborne effluent from nuclear facilities, which has the following advantages: By setting a first optical aerosol particle size spectrometer near the nuclear facility chimney in the sampling tube, and then setting a second optical aerosol particle size spectrometer at the other end of the sampling tube, the proportion of aerosol particle loss in the sampling tube can be obtained by comparing the mass ratio of aerosol particles at both ends of the sampling tube. Then, after nuclide detection and collection of aerosol particles containing strontium-90, the actual emission amount can be accurately obtained. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this utility model, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings:

[0018] Figure 1 This is an overall diagram of a nuclear facility gaseous effluent electrostatic collection and monitoring device according to one embodiment of the present invention;

[0019] Figure 2 This is an overall diagram of a nuclear facility gaseous effluent electrostatic collection and monitoring device according to one embodiment of the present invention.

[0020] Figure Labels

[0021] 1. Chimney; 2. Sampling tube; 3. First flow meter; 4. First switching valve; 5. First optical aerosol particle size spectrometer; 6. Second switching valve; 7. Second optical aerosol particle size spectrometer; 8. Adapter assembly; 9. Ionization unit; 10. Ionization wire; 11. Sealing cylinder; 12. Electrode wire; 13. Sealing cover; 14. High voltage power supply; 15. Collection filter paper; 16. High-purity germanium detector; 17. Second flow meter; 18. Vacuum filtration pump. Detailed Implementation

[0022] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "upper," "inner," and "outer" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0023] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0024] Figure 1 and Figure 2 This invention illustrates an electrostatic collection and monitoring device for airborne effluent from a nuclear facility, according to one embodiment of the present invention. This device can be used to detect the emission of radioactive aerosol particles from a nuclear facility chimney 1. It includes a sampling tube 2 installed inside the nuclear facility chimney 1, an ionization unit 9 connected to the sampling tube 2 for ionizing the aerosol particles transmitted through the sampling tube 2, an electrode adsorption unit for adsorbing the ionized aerosol particles, and a high-purity germanium detector 16 installed within the electrode adsorption unit for detecting nuclides. The sampling tube 2 has a first optical aerosol particle size spectrometer 5 for detecting the mass of aerosol particles near the end of the nuclear facility chimney 1, and a second optical aerosol particle size spectrometer 7 for detecting the mass of aerosol particles near the end of the sampling tube 2 near the ionization unit 9.

[0025] By installing a first optical aerosol particle size spectrometer 5 near the nuclear facility chimney 1 in the sampling tube 2, and a second optical aerosol particle size spectrometer 7 at the other end of the sampling tube 2, the proportion of aerosol particle loss in the sampling tube 2 can be obtained by comparing the mass ratio of aerosol particles at both ends of the sampling tube 2. Then, after nuclide detection and collection of aerosol particles containing strontium-90, the actual emission amount can be accurately obtained by correcting the proportion.

[0026] Understandably, nuclear facility chimney 1 emits a large amount of radioactive aerosol particles, making it unsuitable for staff to conduct detection. Typically, a pipeline several hundred meters long needs to be built to extract the emitted aerosol particles for detection. However, aerosol particles can accumulate inside the pipeline, resulting in a significant difference in emissions compared to the final stage.

[0027] In one specific embodiment, the electrostatic collection and monitoring device for gaseous effluent from a nuclear facility is equipped with a computer. The computer is electrically connected to a first optical aerosol particle size spectrometer 5, a second optical aerosol particle size spectrometer 7, and a high-purity germanium detector 16. The γ nuclide obtained by the high-purity germanium detector 16 can be immediately corrected by the mass ratio of the first optical aerosol particle size spectrometer 5 and the second optical aerosol particle size spectrometer 7. After the content of strontium-90 in the aerosol particles collected by the subsequent electrode adsorption unit is detected, the information is input into the computer for correction.

[0028] In one specific embodiment, the ionization device is provided with an ionization wire 10 for ionizing aerosol particles.

[0029] In one specific embodiment, the ionization device is provided with a transfer component 8 connected to the sampling tube 2, and the transfer component 8 is a sealed connection between the sampling tube 2 and the ionization device.

[0030] Figure 1 The first optical aerosol particle size spectrometer 5, as shown in one embodiment, may include a first switching valve 4 at the connection between the first optical aerosol particle size spectrometer 5 and the sampling tube 2, and a second switching valve 6 at the connection between the second optical aerosol particle size spectrometer 7 and the sampling tube 2. When detection is not required, the first switching valve 4 and the second switching valve 6 can be closed to reduce the damage of the radiation-containing chimney gas to the first optical aerosol particle size spectrometer 5 and the second optical aerosol particle size spectrometer 7, thereby improving the service life of the first optical aerosol particle size spectrometer 5 and the second optical aerosol particle size spectrometer 7.

[0031] In one specific embodiment, the first switching valve 4 and the second switching valve 6 are flow control valves. The opening degree of the flow control valves can be from 0% to 100%, which can control the flow rate of gas entering the first optical aerosol particle size spectrometer 5 and the second optical aerosol particle size spectrometer 7.

[0032] Figure 1 and Figure 2 The electrode adsorption unit shown in one embodiment may include a sealed cylinder 11, and an ionization unit 9 disposed inside the sealed cylinder 11. The end of the ionization unit 9 away from the sampling tube 2 is in contact with the electrode adsorption unit. After the ionization unit 9 ionizes the aerosol particles, the aerosol particles can pass directly into the electrode adsorption unit through the sealed cylinder 11, thus preventing the aerosol particles from being lost to the outside world and affecting the accuracy of the detection.

[0033] In one specific embodiment, the sealing cylinder 11 is cylindrical, which can reduce corners and avoid aerosol particle deposition.

[0034] Figure 1 and Figure 2The electrode adsorption unit shown in one embodiment may include a plurality of electrode wires 12 for adsorbing aerosol particles and a plurality of collection filter papers 15 for collecting aerosol particles. The collection filter papers 15 can collect and filter aerosol particles. After the collection filter papers 15 are removed from the sealed cylinder 11, they are sent to the laboratory for Strontium-90 detection.

[0035] Figure 1 and Figure 2 The illustration shows that in one embodiment, the collection filter paper 15 may include layers of collection filter paper 15 arranged around the high-purity germanium detector 16, with the collection filter paper 15 perpendicular to the airflow direction within the sealed cylinder 11, and the collection filter paper 15 contacting aerosol particles in the airflow with the maximum area to improve collection efficiency.

[0036] Figure 1 In one embodiment, the sealing cylinder 11 may include a sealing cap 13 detachably connected to the end of the sealing cylinder 11 away from the ionization unit 9, which facilitates the removal of the collection filter paper 15.

[0037] In one specific embodiment, the sealing cap 13 and the sealing cylinder 11 are threaded together, which can ensure sealing while facilitating removal.

[0038] Figure 1 In one embodiment, the sealing cap 13 may include a filtration pump 18 for drawing in and filtering air from the sealing cylinder 11. The filtration pump 18 can draw in air while filtering out aerosol particles to prevent them from being discharged into the external environment and causing pollution.

[0039] Figure 1 The sampling tube 2 is shown in one embodiment to include a first flow meter 3 for detecting the flow rate of the sampling tube 2 at one end near the nuclear facility chimney 1. The first flow meter 3 can detect the gas flow rate in the sampling tube 2.

[0040] In one specific embodiment, the first flow meter 3 is electrically connected to the computer, and the flow data of the first flow meter 3 is fed back to the computer. The computer uses the flow data to assist in the analysis of the detection results of nuclides and strontium-90.

[0041] Figure 1 The sampling tube 2 is shown in one embodiment to include a second flow meter 17 at a high-purity germanium detector 16 for detecting the flow rate of the outgoing gas. The second flow meter 17 can accurately obtain the sampling volume of the aerosol.

[0042] In one specific embodiment, the second flow meter 17 is electrically connected to the computer, and the flow data of the second flow meter 17 is fed back to the computer. The computer uses the flow data to assist in the analysis of the detection results of nuclides and strontium-90.

[0043] Figure 1The ionization unit 9 is shown in one embodiment to include a high-voltage power supply 14 for providing high-voltage current to the ionization unit 9 and the electrode adsorption unit, the high-voltage power supply 14 providing a voltage range of 5 kV to 20 kV.

[0044] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A device for electrostatic collection and monitoring of gaseous effluent from a nuclear facility, characterized in that, include: A sampling tube (2) installed in the chimney (1) of the nuclear facility, an ionization unit (9) connected to the sampling tube (2) for ionizing the aerosol particles transmitted by the sampling tube (2), an electrode adsorption unit for adsorbing the ionized aerosol particles, and a high-purity germanium detector (16) installed in the electrode adsorption unit for detecting nuclides. The sampling tube (2) is equipped with a first optical aerosol particle size spectrometer (5) for detecting the mass of aerosol particles at one end near the nuclear facility chimney (1), and a second optical aerosol particle size spectrometer (7) for detecting the mass of aerosol particles at one end near the ionization unit (9).

2. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 1, characterized in that, A first switching valve (4) is provided at the connection between the first optical aerosol particle size spectrometer (5) and the sampling tube (2), and a second switching valve (6) is provided at the connection between the second optical aerosol particle size spectrometer (7) and the sampling tube (2).

3. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 1, characterized in that, The electrode adsorption unit is provided with a sealing cylinder (11), and the ionization unit (9) is disposed inside the sealing cylinder (11). The end of the ionization unit (9) away from the sampling tube (2) is in contact with the electrode adsorption unit.

4. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 3, characterized in that, The electrode adsorption unit includes several electrode wires (12) for adsorbing aerosol particles and several collection filter papers (15) for collecting aerosol particles.

5. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 4, characterized in that, Each layer of the collecting filter paper (15) is arranged around the high-purity germanium detector (16), and the collecting filter paper (15) is perpendicular to the airflow direction inside the sealed cylinder (11).

6. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 5, characterized in that, The sealing cylinder (11) has a sealing cap (13) that is detachably connected to the sealing cylinder (11) at one end away from the ionization unit (9).

7. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 6, characterized in that, The sealing cap (13) is equipped with a filtration pump (18) for drawing out and filtering the air inside the sealing cylinder (11).

8. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 1, characterized in that, The sampling tube (2) is equipped with a first flow meter (3) for detecting the flow rate of the sampling tube (2) at one end near the nuclear facility chimney (1).

9. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 1, characterized in that, The high-purity germanium detector (16) is equipped with a second flow meter (17) for detecting the flow rate of the outgoing gas.

10. The electrostatic collection and monitoring device for gaseous effluent from a nuclear facility according to claim 1, characterized in that, The ionization unit (9) is provided with a high-voltage power supply (14) for providing high-voltage current to the ionization unit (9) and the electrode adsorption unit, the high-voltage power supply (14) providing a voltage range of 5 kV to 20 kV.

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