Power tube structure for Po-210 protection device and performance test method thereof

Abstract

The application discloses a power pipe structure for a Po-210 protection device and a performance testing method thereof, relates to the technical field of radioactive waste gas treatment, and the power pipe structure comprises a pipe body, open ends are arranged at both ends of the pipe body, pipe caps are arranged at the open ends, sealing pads are arranged at the connecting positions of the pipe caps and the pipe body, a plurality of sieve plates are arranged in the pipe body, the plurality of sieve plates divide the pipe body into a plurality of cavities, and filter materials are arranged in the cavities. The power pipe structure can be used for testing the performance of a plurality of candidate Po trapping materials, verifying the structure and performance optimization of a subsequent protection filter box, guiding the selection of Po-210 filter materials and the design and optimization of a Po-210 personal protection device, and providing support for the protection of personnel in the operation and maintenance processes of a subsequent lead-bismuth fast reactor. The performance testing method can accurately measure the filtration efficiency of the power pipe structure, and thus facilitates the detection of the filtration performance of the Po-210 protection device.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste gas treatment technology, specifically to a power pipe structure for a Po-210 protective device and its performance testing method. Background Technology

[0002] Polonium-210 (Po) is an extremely toxic radioactive nuclide that readily forms Polonium-210 aerosols with a half-life of 138.4 days. If it enters the body, it can damage the structure of human tissues and organs, harm DNA, and lead to cell death. There is a possibility of Polonium-210 leakage in certain nuclear facilities (such as lead-bismuth fast reactors), which could have serious effects on workers and the environment. The relative concentration of Polonium-210 is particularly high in high-temperature environments such as cover gases. Even under normal operating conditions, there is a risk of Po leakage into the ambient gas. When monitoring equipment does not detect any radioactive risk, or detects only low to medium concentrations, it is necessary to wear Po-210 protective equipment for low to medium concentration scenarios and to conduct regular inspections and maintenance. Therefore, there is a need to develop Po protective devices suitable for capturing and adsorbing Po-210-containing gases in radioactive environments.

[0003] Patent CN109166641B discloses a low-level radioactive waste gas treatment system for a lead-bismuth pile. The system includes a waste gas inlet for inputting the radioactive waste gas to be treated, a filtration unit for filtering aerosols and particulate matter from the waste gas, a compression and storage unit for pressurizing and temporarily storing the filtered waste gas, a retention unit for retaining and decaying the waste gas output from the compression and storage unit, and a radioactive monitoring unit for collecting waste gas from multiple locations within the system and analyzing its radioactive concentration. The waste gas inlet, filtration unit, compression and storage unit, and retention unit are sequentially connected via pipelines. The filtration unit includes a first filter and a second filter. The first filter performs preliminary filtration of aerosols and particulate matter in the waste gas input through the waste gas inlet; the second filter performs secondary filtration of aerosols and particulate matter in the pre-filtered waste gas.

[0004] Currently, the publicly disclosed methods for treating radioactive waste gas typically employ filtration, as disclosed in the aforementioned patent. Filters are used to filter aerosols and particulate matter in the waste gas. The filtration performance of the Po trapping filter material used in the filter is extremely important for the final treatment effect of the radioactive waste gas. Moreover, due to the special physicochemical properties of Po-210, it is necessary to test the protective performance of the Po trapping filter material. However, there are currently no reports on testing the protective performance of Po trapping filter materials used in Po-210 protection devices. Summary of the Invention

[0005] Addressing the current lack of testing methods for the protective performance of Po trapping filter media used in Po-210 protective devices, the present invention aims to provide a power tube structure for Po-210 protective devices and its performance testing method. This power tube structure can perform performance testing on various candidate Po trapping materials, as well as verify the structural and performance optimization of subsequent protective filter boxes, guiding the selection of Po-210 trapping filter media and the design and optimization of Po-210 personal protective equipment, thus providing support for personnel protection during the operation and maintenance of lead-bismuth fast reactors.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, this application provides a power pipe structure for a Po-210 protection device, including a pipe body, both ends of which are provided with openings and pipe caps are installed at the openings, and a sealing gasket is installed at the connection between the pipe caps and the pipe body; multiple sieve plates are installed inside the pipe body, and the multiple sieve plates divide the pipe body into multiple cavities, and Po trapping filter media are installed in the cavities.

[0008] When assembling this power pipe structure, first fill the pipe body with Po trapping filter media and separate it with a sieve plate. Then seal the pipe cap to the pipe body with a sealing gasket and screws.

[0009] Furthermore, the cap has a conical structure.

[0010] Furthermore, the inner diameter of the larger end of the cap is 2cm to 4cm, and the length is 3cm to 12cm; the inner diameter of the smaller end of the cap is 1mm to 50mm, and the length is 0.2cm to 2cm.

[0011] The inner diameter of the large end of the conical cap can be 2cm, 2.5cm, 3cm, 3.5cm, 4cm, or any size within the range of 2cm to 4cm. The specific size can be determined based on the inner diameter of the pipe body, with the aim of achieving a sealed connection between the cap and the pipe body.

[0012] The length of the wide end of the conical cap can be any size within the range of 3cm, 3.5cm, 4cm, 4.5cm, 5cm, 5.5cm, 6cm, 6.5cm, 7cm, 7.5cm, 8cm, 8.5cm, 9cm, 9.5cm, 10cm, 10.5cm, 11cm, 11.5cm, or 3cm to 12cm, depending on the actual needs.

[0013] The inner diameter of the small end of the cone-shaped cap can be any size within the range of 1mm to 50mm, including 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, and 50mm. The size can be determined based on actual needs.

[0014] The length of the small end of the cone-shaped cap can be any size within the range of 0.2cm, 0.3cm, 0.4cm, 0.5cm, 0.6cm, 0.7cm, 0.8cm, 0.9cm, 1.0cm, 1.1cm, 1.2cm, 1.3cm, 1.4cm, 1.5cm, 1.6cm, 1.7cm, 1.8cm, 1.9cm, or 2cm, depending on the actual needs.

[0015] Furthermore, the total weight of the Po trapping filter material installed inside the tube is 10g~200g.

[0016] The total weight of the Po collection filter media installed inside the tube can be any value within the range of 10g, 20g, 30g, 40g, 50g, 60g, 70g, 80g, 90g, 100g, 110g, 120g, 130g, 140g, 150g, 160g, 170g, 180g, 190g, 200g, or 10g to 200g, depending on actual needs.

[0017] The power tube structure in this invention can be used in Po-210 protective devices, enabling performance testing of various candidate Po trapping materials, as well as subsequent structural and performance optimization verification of protective filter boxes. It guides the selection of Po-210 trapping filter materials and the design and optimization of Po-210 personal protective equipment, providing support for personnel protection during the operation and maintenance of lead-bismuth fast reactors.

[0018] Secondly, this application provides a Po-210 protection device, including the aforementioned power pipe structure.

[0019] Thirdly, this application provides a performance testing device for the power pipe structure of a Po-210 protection device, comprising a power pipe structure installed on a gas pipeline, wherein two parallel gas branch pipelines are provided at the front and rear ends of the power pipe structure, a first gas washing bottle and a first rotor flow meter are connected to the gas branch pipeline at the gas inlet end of the power pipe structure, and a second gas washing bottle and a second rotor flow meter are connected to the gas branch pipeline at the gas outlet end of the power pipe structure.

[0020] Furthermore, both the first and second gas washing bottles contain nitric acid solution.

[0021] Fourthly, this application provides a performance testing method for a power pipe structure, using the aforementioned performance testing device, comprising the following steps:

[0022] Install the Po trapping filter media in the power pipe;

[0023] Inject nitric acid solution into the first and second gas washing bottles, and then turn off the first and second rotor flow meters;

[0024] Perform an airtightness test on the entire testing device and maintain the pressure until the pressure change is no greater than 5kPa-20kPa; the pressure holding time can be 5min-30min.

[0025] The holding time can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, or 30 min, or any value within the range of 5 min to 30 min, depending on the actual situation.

[0026] Po-containing aerosol is introduced into the performance testing device through a gas pipeline, and the Po-containing aerosol passes through the power pipe structure, the first gas washing bottle, and the second gas washing bottle;

[0027] Set the ventilation time according to the protection time required by the Po-210 protective device, and stop ventilation after the preset time is reached;

[0028] Take the same volume of solution from the first and second gas washing bottles, add Po-209 tracer to each, and analyze the activity concentration of Po-210 to obtain the collection efficiency of the Po collection filter material.

[0029] The Po trapping filter media inside the power tube structure was removed layer by layer. The alpha radioactivity of each layer of Po trapping filter media was measured. The filtration efficiency of a single layer of Po trapping filter media was calculated. The total filtration efficiency of the device was then calculated to verify the filtration efficiency obtained from the gas washing bottle.

[0030] Based on the Po-210 activity concentration calculated from the second gas washing bottle and referring to the Po-210 limit in air, the protection time was calculated; and under the protection time, the Po-210 concentration after gas washing was measured to further verify the accuracy of the protection time.

[0031] The gas pipeline inlet provides air intake for the entire performance testing device, allowing gas containing low to medium concentrations of Po aerosol to enter. A device that generates Po aerosol is connected to the gas pipeline inlet. Po-catching filter media within the power pipe structure specifically adsorbs Po, achieving highly efficient adsorption and retention. The gas, after adsorption by the Po-catching filter media, is discharged from the pipeline outlet. The discharged gas undergoes testing; if further filtration is required, it is released before being discharged. The first and second gas washing bottles are used to wash the gas before and after passing through the power pipe structure, respectively, transferring Po from the gas phase to the liquid phase. Both the first and second gas washing bottles contain high-concentration nitric acid solutions. A first rotor flowmeter controls the inlet flow rate of the first gas washing bottle, and a second rotor flowmeter controls the inlet flow rate of the second gas washing bottle.

[0032] Furthermore, the flow rate of Po aerosol at the gas pipeline inlet is controlled at 1 SLPM-30 SLPM, with an accuracy better than or equal to ±0.5 FS.

[0033] The flow rate of Po aerosol at the gas pipeline inlet can be 1 SLPM, 2 SLPM, 3 SLPM, 4 SLPM, 5 SLPM, 6 SLPM, 7 SLPM, 8 SLPM, 9 SLPM, 10 SLPM, 11 SLPM, 12 SLPM, 13 SLPM, 14 SLPM, 15 SLPM, 16 SLPM, 17 SLPM, 18 SLPM, 19 SLPM, 20 SLPM, 21 SLPM, 22 SLPM, 23 SLPM, 24 SLPM, 25 SLPM, 26 SLPM, 27 SLPM, 28 SLPM, 29 SLPM, or 30 SLPM, or any value within the range of 1 SLPM to 30 SLPM, which can be determined according to actual needs.

[0034] Furthermore, the activity concentration of Po in the Po aerosol at the gas pipeline inlet was 11.1 Bq / m³. 3 -111.0 Bq / m 3 .

[0035] Specifically, the activity concentration of Po in the Po aerosol at the gas pipeline inlet can be 11.1 Bq / m³. 3 15.0 Bq / m 3 20.0 Bq / m 3 25.0 Bq / m 3 30.0 Bq / m 3 35.0 Bq / m 3 40.0 Bq / m 3 45.0 Bq / m 3 50.0 Bq / m 3 55.0 Bq / m 3 60.0 Bq / m 3 65.0 Bq / m 3 70.0 Bq / m 3 75.0 Bq / m 3 80.0 Bq / m 3 85.0 Bq / m 3 90.0 Bq / m 3 95.0 Bq / m 3 100.0 Bq / m 3 105.0 Bq / m 3 111.0 Bq / m 3 It can also be 11.1 Bq / m 3 -111.0 Bq / m 3 Any value within the range can be determined according to actual needs.

[0036] Furthermore, the concentration of nitric acid used in the first and second gas washing bottles is 1 mol / L to 10 mol / L. The volume of the first and second gas washing bottles can be 100 mL to 1000 mL, and each bottle contains 20 mL to 300 mL of nitric acid.

[0037] The concentration of nitric acid used in the first and second gas washing bottles can be 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, or 10 mol / L, or any value within the range of 1 mol / L to 10 mol / L, and can be determined according to actual needs.

[0038] The volumes of the first and second gas washing bottles can be 100mL, 150mL, 200mL, 250mL, 300mL, 350mL, 400mL, 450mL, 500mL, 550mL, 600mL, 650mL, 700mL, 750mL, 800mL, 850mL, 900mL, 950mL, or 1000mL, or any value within the range of 100mL to 1000mL, and can be determined according to actual needs.

[0039] The volume of nitric acid placed in the bottle can be 20mL, 30mL, 40mL, 50mL, 60mL, 70mL, 80mL, 90mL, 100mL, 110mL, 120mL, 130mL, 140mL, 150mL, 160mL, 170mL, 180mL, 190mL, 200mL, 210mL, 220mL, 230mL, 240mL, 250mL, 260mL, 270mL, 280mL, 290mL, or 300mL, or any value within the range of 20mL to 300mL, depending on the actual needs.

[0040] Furthermore, the maximum range of the first and second rotor flow meters is not less than 0.5 L / min, and the flow rate is set to 0.1 L / min to 0.5 L / min during use.

[0041] The flow rates set for the first and second rotor flow meters during use can be 0.1L / min, 0.2L / min, 0.3L / min, 0.4L / min, or 0.5L / min, or any value within the range of 0.1L / min to 0.5L / min, depending on actual needs.

[0042] Furthermore, during the testing, 0.1 Bq-10 Bq Po-209 tracer was added to the first and second gas washing bottles, respectively.

[0043] During testing, the Po-209 tracer added to the first and second gas washing bottles can be 0.1 Bq, 1 Bq, 2 Bq, 3 Bq, 4 Bq, 5 Bq, 6 Bq, 7 Bq, 8 Bq, 9 Bq, or 10 Bq, or any value within the range of 0.1 Bq to 10 Bq, depending on actual needs.

[0044] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0045] (1) Based on the power tube structure in this invention, the performance of various candidate Po trapping materials is tested, and the structure and performance of the subsequent protective filter box are optimized and verified, guiding the selection of Po-210 trapping filter material and the design and optimization of Po-210 personal protective equipment, providing support for personnel protection during the operation and maintenance of the subsequent lead-bismuth fast reactor.

[0046] (2) The power pipe structure of the present invention has good scalability and can simulate the core component in the protective device—the protective filter box.

[0047] (3) The Po-210 performance test method of the present invention is based on the overall filtration effect of the gas washing bottle and the cumulative filtration efficiency of the Po-210 trapping filter material in the power tube structure. The combination of the two can accurately measure the filtration efficiency of the power tube structure, thereby facilitating the detection of the filtration performance of the Po-210 protection device. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0049] Figure 1 This is a schematic diagram of a power pipe structure for a Po-210 protection device according to the present invention;

[0050] Figure 2 for Figure 1 Enlarged view of A in the middle;

[0051] Figure 3 This is a schematic diagram of the cone-shaped cap in this invention;

[0052] Figure 4 This is a schematic diagram of the performance testing device for the power pipe structure in this invention. Attached Figure Description

[0054] 01-Pipe cap, 02-Pipe body, 03-Sieve plate, 04-PO collection filter media, 05-Sealing gasket, 06-Second rotor flow meter, 07-Power pipe structure, 08-Gas pipeline, 09-First gas washing bottle, 10-First rotor flow meter, 11-Second gas washing bottle. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0056] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the power pipe structure for the Po-210 protective device and its performance testing method. However, unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0057] The "scope" disclosed in this application is defined by a lower limit and an upper limit. A given scope is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific scope. A scope defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a scope. Unless otherwise specified, the terms "comprising" and "including" in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that it may also include or include other substances not listed, or it may only include or include the listed substances.

[0058] In this application, the terms "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "high," "low," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention. The terms "first," "second," etc., used in this invention are merely for the purpose of clarity in distinguishing corresponding components and are not intended to limit any order or emphasize importance. Furthermore, the term "connection" used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0059] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example 1

[0060] like Figures 1-3 As shown, this embodiment provides a power pipe structure for a Po-210 protection device, including a pipe body 02, with openings at both ends of the pipe body 02, and a conical cap 01 installed at each opening. A sealing gasket 05 is installed at the connection between the conical cap 01 and the pipe body 02. Multiple sieve plates 03 are installed inside the pipe body 02, and the multiple sieve plates 03 divide the pipe body 02 into multiple cavities. Po trapping filter media 04 is installed inside the cavities.

[0061] Specifically, the inner diameter of the large end of the conical cap 01 is 2cm~4cm, and the length is 3cm~12cm; the inner diameter of the small end of the cap 01 is 1mm~50mm, and the length is 0.2cm~2cm.

[0062] Specifically, the total weight of the Po trapping filter material 04 installed inside the tube 02 is 10g~200g.

[0063] This power tube structure can be used in Po-210 protective devices, enabling performance testing of various candidate Po trapping materials, as well as subsequent structural and performance optimization verification of protective filter cartridges. It guides the selection of Po trapping filter material 04 and the design and optimization of Po-210 personal protective equipment, providing support for personnel protection during the operation and maintenance of lead-bismuth fast reactors. Example 2

[0064] like Figures 1-4 As shown, this embodiment provides a performance testing device for the power pipe structure of a Po-210 protection device, including a power pipe structure 07 installed on a gas pipeline 08. Two parallel gas branch pipelines are provided at the front and rear ends of the power pipe structure 07. A first gas washing bottle 09 and a first rotor flow meter 10 are connected to the gas branch pipeline at the gas inlet end of the power pipe structure 07, and a second gas washing bottle 11 and a second rotor flow meter 06 are connected to the gas branch pipeline at the gas outlet end of the power pipe structure 07.

[0065] The power pipe structure 07 in this embodiment is the same as the power pipe structure 07 in Embodiment 1. Specifically, it includes a pipe body 02, with openings at both ends, and a conical cap 01 installed at each opening. A sealing gasket 05 is installed at the connection between the conical cap 01 and the pipe body 02. Multiple sieve plates 03 are installed inside the pipe body 02, dividing it into multiple cavities. Po-collecting filter media 04 is installed inside each cavity. The inner diameter of the larger opening of the conical cap 01 is 2cm~4cm, and its length is 3cm~12cm. The inner diameter of the smaller opening of the cap 01 is 1mm~50mm, and its length is 0.2cm~2cm. The total weight of the Po-collecting filter media 04 installed inside the pipe body 02 is 10g~200g.

[0066] Specifically, both the first gas washing bottle 09 and the second gas washing bottle 11 contain nitric acid solution; the concentration of nitric acid is 1 mol / L-10 mol / L; the volume of the first gas washing bottle 09 and the second gas washing bottle 11 can be 100 mL to 1000 mL, and 20 mL to 300 mL of nitric acid is placed in the bottle.

[0067] The inlet of gas pipeline 08 provides air intake for the entire performance testing device, allowing gas containing low to medium concentrations of Po aerosol to enter the device. A device capable of generating Po aerosol is connected to the inlet of gas pipeline 08. Po-collecting filter material 04 installed within the power pipe structure 07 is used for specific adsorption of Po, achieving efficient adsorption and retention. The gas, after adsorption by the Po-collecting filter material 04, is discharged from the pipeline outlet. If further filtration is required after testing, the discharged gas is then subjected to further filtration before being released. The first gas washing bottle 09 and the second gas washing bottle 11 are used to wash the gas before and after passing through the power pipe structure 07, respectively, transferring Po from the gas phase to the liquid phase. Both the first gas washing bottle 09 and the second gas washing bottle 11 contain high-concentration nitric acid solutions. The first rotor flowmeter 10 controls the inlet flow rate of the first gas washing bottle 09, and the second rotor flowmeter 06 controls the inlet flow rate of the second gas washing bottle 11.

[0068] This performance testing device, based on the power tube structure 07 in Embodiment 1 and the connection structure of the first gas washing bottle 09 and the second gas washing bottle 11 connected in the gas pipeline 08, can accurately measure the filtration efficiency of the power tube structure 07, thereby facilitating the testing of the filtration performance of the Po-210 protection device. Example 3

[0069] like Figures 1-4 As shown, this embodiment provides a performance testing method for the power pipe structure of a Po-210 protection device, using the performance testing device in Embodiment 2. The specific testing steps are as follows:

[0070] S1. Install the Po trapping filter media 04 inside the tube body 02 of the power pipe structure 07;

[0071] S2. Inject 100mL~1000mL of 1mol / L-10mol / L nitric acid solution into the first gas washing bottle 09 and the second gas washing bottle 11, and close the first rotor flow meter 10 and the second rotor flow meter 06.

[0072] S3. Perform an airtightness test on the entire testing device, maintain pressure for 5 to 30 minutes, until the pressure change is no greater than 5 kPa to 20 kPa.

[0073] S4. Open the Po-210 aerosol generator, the first rotor flow meter 10, the second rotor flow meter 06 and the corresponding pipeline valves, so that the gas containing Po aerosol flows through the power pipe structure 07, the first gas washing bottle 09, and the second gas washing bottle 11.

[0074] Specifically, the protection time of the protective filter cartridge in low to medium concentration scenarios is 30 min to 120 min, and the filtration performance test with equivalent protection time is carried out based on this testing device;

[0075] Specifically, the maximum range of the first rotor flowmeter 10 and the second rotor flowmeter 06 is not less than 0.5L / min, and the flow rate is set to 0.1L / min~0.5L / min during use;

[0076] Specifically, the activity concentration of Po in the Po aerosol at the air inlet of gas pipeline 08 is 11.1 Bq / m3-111.0 Bq / m3;

[0077] Specifically, the concentration of nitric acid used in the first gas washing bottle 09 and the second gas washing bottle 11 is 1mol / L-10mol / L, the volume of the first gas washing bottle 09 and the second gas washing bottle 11 is 100mL-1000mL, and 20mL-300mL of nitric acid is placed in the bottle.

[0078] S5. Set the ventilation time according to the protection time required by the Po-210 protection device. After the predetermined protection time is reached, close the corresponding aerosol generator, the first rotor flow meter 10, the second rotor flow meter 06 and the corresponding pipeline valves.

[0079] S6. Take 50 mL of solution from the first gas washing bottle 09 and the second gas washing bottle 11 respectively, add 0.1 Bq-10 Bq Po-209 tracer respectively, and obtain the collection efficiency of Po trapping filter material 04 by analyzing the activity concentration of Po-210.

[0080] S7. Remove the Po trapping filter material 04 from the power tube structure 07 in layers, measure the α radioactivity of each layer of Po trapping filter material 04, calculate the filtration efficiency of a single layer of Po trapping filter material 04, and calculate the total filtration efficiency of the device to verify the filtration efficiency obtained based on the gas washing bottle.

[0081] S8. Based on the Po-210 activity concentration calculated from the second gas washing bottle 11, and referring to the Po-210 limit in the air, the protection time is calculated; and under the protection time, the concentration of Po-210 after gas washing is measured to further verify the accuracy of the protection time.

[0082] This performance testing method is based on the connection between the power pipe structure 07 and the first gas washing bottle 09 and the second gas washing bottle 11 connected in the gas pipeline 08. The combination of the two can accurately measure the filtration efficiency of the power pipe structure 07, thereby facilitating the testing of the filtration performance of the Po-210 protection device.

[0083] Experimental Case 1

[0084] The protective performance of the power tube structure in the performance testing device of Example 2 is tested using the performance testing method in Example 3. The structure of the testing device includes a power tube structure 07 installed on the gas pipeline 08. Two parallel gas branch pipelines are provided at the front and rear ends of the power tube structure 07. A first gas washing bottle 09 and a first rotor flowmeter 10 are connected to the gas branch pipeline at the gas inlet end of the power tube structure 07. A second gas washing bottle 11 and a second rotor flowmeter 06 are connected to the gas branch pipeline at the gas outlet end of the power tube structure 07.

[0085] The power pipe structure 07 includes a pipe body 02, with openings at both ends of the pipe body 02, and a conical cap 01 installed at each opening. A sealing gasket 05 is installed at the connection between the conical cap 01 and the pipe body 02. Multiple sieve plates 03 are installed inside the pipe body 02, dividing the pipe body 02 into six cavities. Each cavity is equipped with Po collection filter media 04.

[0086] Specifically, the Po trapping filter media used in the power pipe structure is a modified carbon-based material. This material is endowed with the ability to specifically adsorb Po by impregnating the surface or interior of the activated carbon material with metals such as copper, silver, platinum, nickel, and zinc. In this experimental case, a modified carbon-based material with copper impregnated on the surface of the activated carbon material was used.

[0087] Specifically, the inner diameter of the large end of the cone-shaped cap 01 is 3cm and the length is 8cm; the inner diameter of the small end of the cap 01 is 20mm and the length is 1cm.

[0088] Specifically, the total weight of the Po trapping filter material 04 installed inside the tube 02 is 100g.

[0089] The specific testing method is as follows:

[0090] S1. Install the Po trapping filter media 04 inside the tube body 02 of the power pipe structure 07;

[0091] S2. Inject 300 mL of 5 mol / L nitric acid solution into the first gas washing bottle 09 and the second gas washing bottle 11, and close the first rotor flow meter 10 and the second rotor flow meter 06.

[0092] S3. Perform an airtightness test on the entire testing device, maintain pressure for 10 minutes, until the pressure change is no greater than 10 kPa.

[0093] S4. Open the Po-210 aerosol generator, the first rotor flow meter 10, the second rotor flow meter 06 and the corresponding pipeline valves, so that the gas containing Po aerosol flows through the power pipe structure 07, the first gas washing bottle 09, and the second gas washing bottle 11.

[0094] Taking a 30-minute protection time for a protective filter box in a low-to-medium concentration scenario as an example, a filtration performance test with the same protection time was conducted based on this testing device. The designed standard tank diameter is 105mm and the air volume is 30L / min. Based on the diameter D (in mm) of the power pipe, the air intake Q1 of the power pipe can be calculated as: Q1 = 30*(D / 105). 2 Specifically, when the diameter D of the power pipe is 20 mm, the air inlet flow rate Q1 of the power pipe is 1.1 L / min. The flow rates Q2 of the first rotor flowmeter 10 and the second rotor flowmeter 06 are set to 0.1 L / min to 0.5 L / min. Therefore, the flow rate Q of the inlet for low-to-medium concentration Po aerosol is: Q = Q1 + Q2. When the flow rate Q2 of the rotor flowmeter is set to 0.2 L / min and the diameter D of the power pipe is 20 mm, the flow rate Q of the inlet for Po aerosol is 1.3 L / min.

[0095] S5. Based on the protection time required by the Po-210 protection device, set the ventilation time to 30 minutes. After the predetermined protection time is reached, close the corresponding aerosol generator, the first rotor flow meter 10, the second rotor flow meter 06, and the corresponding pipeline valves.

[0096] S6. Take 50 mL of solution from the first gas washing bottle 09 and the second gas washing bottle 11 respectively, add 0.5 Bq Po-209 tracer to each, and obtain the collection efficiency of Po trapping filter material 04 by analyzing the activity concentration of Po-210.

[0097] S7. Remove the Po trapping filter material 04 from the power tube structure 07 in layers, measure the α radioactivity of each layer of Po trapping filter material 04, calculate the filtration efficiency of a single layer of Po trapping filter material 04, and calculate the total filtration efficiency of the device to verify the filtration efficiency obtained based on the gas washing bottle.

[0098] S8. Based on the Po-210 activity concentration calculated from the second gas washing bottle 11, and referring to the Po-210 limit in the air, the protection time is calculated; and under the protection time, the concentration of Po-210 after gas washing is measured to further verify the accuracy of the protection time.

[0099] Tests showed that the Po-210 count in the first gas washing bottle 09 was 14452 cpm, and the Po-210 count in the second gas washing bottle 11 was 10 cpm. Based on the calculation of the change in Po-210 content before and after gas washing, the filtration efficiency was determined to be 99.93%.

[0100] The Po-210 content data of the six-layer Po trap filter media 04 are 564 cpm, 87 cpm, 22 cpm, 7 cpm, 1 cpm, and 0.5 cpm, respectively. Based on the Po-210 counts in the first and last layers of Po trap filter media 04 near the air inlet of the power pipe, the filtration efficiency is determined to be 99.91%.

[0101] Based on the test results of the gas washing bottle and Po trapping filter material 04, it was confirmed that the filtration efficiency of the power tube and Po trapping filter material 04 for Po-210 can reach 99.9%, and the provided power tube and Po trapping filter material 04 can effectively filter Po-210 in the gas space.

[0102] In the description of this specification, the references to "Embodiment 1," "Embodiment 2," "Embodiment 3," etc., indicate that a specific feature, system, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, systems, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A performance testing method for a power pipe structure, characterized in that, The performance testing was conducted using a power pipe structure designed for Po-210 protection devices. The performance testing device includes a power pipe structure (07) installed on a gas pipeline (08). Two parallel gas branch pipelines are provided at the front and rear ends of the power pipe structure (07). A first gas washing bottle (09) and a first rotor flow meter (10) are connected to the gas branch pipeline at the inlet end of the power pipe structure (07). A second gas washing bottle (11) and a second rotor flow meter (06) are connected to the gas branch pipeline at the outlet end of the power pipe structure (07). The power pipe structure includes a pipe body (02), with openings at both ends of the pipe body (02) and a pipe cap (01) installed at each opening. A sealing gasket (05) is installed at the connection between the pipe cap (01) and the pipe body (02). Multiple sieve plates (03) are installed inside the pipe body (02), and the multiple sieve plates (03) divide the pipe body (02) into multiple cavities. Po trapping filter media (04) are installed inside the cavities. The cap (01) has a conical structure; The inner diameter of the large end of the cap (01) is 2cm~4cm and the length is 3cm~12cm; the inner diameter of the small end of the cap (01) is 1mm~50mm and the length is 0.2cm~2cm. The testing method using the aforementioned performance testing device includes the following steps: Install the Po trapping filter media (04) in the power pipe; Inject nitric acid solution into the first gas washing bottle (09) and the second gas washing bottle (11), and close the first rotor flow meter (10) and the second rotor flow meter (06); Perform an airtightness test on the entire testing device and maintain the pressure until the pressure change is no greater than 5kPa-20kPa. The Po-containing aerosol is introduced into the performance testing device through the gas pipeline (08), and the Po-containing aerosol passes through the power pipe structure (07), the first gas washing bottle (09), and the second gas washing bottle (11). Set the ventilation time according to the protection time required by the Po-210 protective device, and stop ventilation after the preset time is reached; Take the same volume of solution from the first gas washing bottle (09) and the second gas washing bottle (11), add Po-209 tracer to each, and analyze the activity concentration of Po-210 to obtain the collection efficiency of Po collection filter material (04). The Po trapping filter material (04) inside the power tube structure (07) was removed layer by layer. The α radioactivity of the Po trapping filter material (04) in each layer was measured. The filtration efficiency of a single layer of Po trapping filter material (04) was calculated. The total filtration efficiency of the device was then calculated to verify the trapping efficiency obtained based on the gas washing bottle. Based on the Po-210 activity concentration calculated from the second gas washing bottle (11), and with reference to the Po-210 limit in the air, the protection time is calculated; and under the protection time, the concentration of Po-210 after gas washing is measured to further verify the accuracy of the protection time.

2. The performance testing method for a power pipe structure according to claim 1, characterized in that, The total weight of the Po trapping filter material (04) installed inside the tube (02) is 10g~200g.

3. The performance testing method for a power pipe structure according to claim 1, characterized in that, Both the first gas washing bottle (09) and the second gas washing bottle (11) contain nitric acid solution.

4. The performance testing method for a power pipe structure according to claim 1, characterized in that, The flow rate of Po aerosol at the air inlet of the gas pipeline (08) is controlled at 1 SLPM-30 SLPM.

5. The performance testing method for a power pipe structure according to claim 1, characterized in that, The activity concentration of Po in the Po aerosol at the air inlet of the gas pipeline (08) is 11.1 Bq / m3-111.0 Bq / m3.

6. The performance testing method for a power pipe structure according to claim 1, characterized in that, The concentration of nitric acid used in the first gas washing bottle (09) and the second gas washing bottle (11) is 1 mol / L-10 mol / L.

7. The performance testing method for a power pipe structure according to claim 1, characterized in that, The maximum range of the first rotor flowmeter (10) and the second rotor flowmeter (06) is not less than 0.5L / min, and the flow rate is set to 0.1L / min~0.5L / min during use.

8. The performance testing method for a power pipe structure according to claim 1, characterized in that, During testing, 0.1 Bq-10 Bq Po-209 tracer was added to the first gas washing bottle (09) and the second gas washing bottle (11), respectively.

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