Adsorption sampling device for radioactive substances and radioactive gas sampling system for nuclear power station

Abstract

The invention discloses a radioactive substance adsorption sampling device which comprises an inlet shell, a middle shell and an outlet shell which are connected in sequence, the inlet shell and the outlet shell are each provided with a cavity structure with the two ends communicated, the inlet shell is provided with a first airflow channel, and the outlet shell is provided with a second airflow channel; a porous third airflow channel is formed in the middle shell, an aerosol filtering layer is arranged between the inlet shell and the middle shell, and a radioactive iodine adsorption container is arranged in the second airflow channel of the outlet shell; gas flows into the first gas flow channel of the inlet shell, sequentially passes through the aerosol filtering layer, the third gas flow channel and the radioactive iodine adsorption container, and then flows out of the outlet shell from the second gas flow channel. The adsorption sampling device is used in a radioactive gas sampling system of a nuclear power station, and is convenient to use and relatively good in performance.

Description

Technical Field

[0001] The invention relates to the technical field of radioactive material sampling, in particular to an adsorption sampling device for radioactive material and a radioactive gas sampling system for a nuclear power plant. Background Art

[0002] In the containment atmosphere and exhaust gas system of a nuclear power plant, some radioactive iodine, aerosols and impurity particles will inevitably be produced after long-term operation. When it is required to measure the activity of aerosols and radioactive iodine in the gas, it is necessary to obtain a certain amount of test system gas samples, and then use a special device to filter and adsorb the radioactive iodine, aerosols and impurity particles. The collected samples are used to analyze the activity of aerosols and radioactive iodine in the test gas.

[0003] The radioactive iodine adsorption sampling device in the test system is part of the supporting equipment of the nuclear sampling system of the nuclear power plant. It is used to filter and adsorb the radioactive substance iodine, aerosols and impurity particles in the test gas. The collected samples are used to analyze and measure the activity of aerosols and radioactive iodine in the test gas.

[0004] The prior art CN111220428A discloses a multi-channel test device for sampling radioactive aerosols and gaseous iodine, comprising an exhaust mechanism, and a plurality of parallel sampling gas paths connected to the exhaust mechanism, wherein the sampling gas paths comprise a sample fixture, a sampling branch pipe and a sampling branch pipe, the interior of the sample fixture is filled with aerosol filter material and gaseous iodine adsorption material to be tested, one end of the sample fixture is provided with an air inlet, and the other end is provided with an air outlet, the air inlet is connected to the sampling branch pipe, the air outlet is connected to the sampling branch pipe, and the sampling branch pipe is connected to the exhaust mechanism.

[0005] The existing radioactive iodine adsorption sampling device has the problems of complex system, large volume, inconvenient assembly and disassembly and use.

[0006] In view of the above technical problems, the present invention is specially introduced. Summary of the invention

[0007] The main purpose of the present invention is to provide a radioactive material adsorption sampling device and a nuclear power plant radioactive gas sampling system for filtering and adsorbing radioactive material iodine, aerosol and impurity particles in the test gas to obtain samples of radioactive aerosol and radioactive iodine.

[0008] In order to achieve the above object, according to one aspect of the present invention, a radioactive material adsorption sampling device is provided, comprising an inlet shell, an intermediate shell and an outlet shell connected in sequence, wherein the inlet shell and the outlet shell both have a cavity structure with two ends connected, so that the inlet shell has a first airflow channel, and the outlet shell has a second airflow channel;

[0009] The intermediate shell is provided with a porous third airflow channel, an aerosol filter layer is provided between the inlet shell and the intermediate shell, and a radioactive iodine adsorption container is provided in the second airflow channel of the outlet shell;

[0010] The gas flows into the first air flow channel of the inlet housing, passes through the aerosol filter layer, the third air flow channel and the radioactive iodine adsorption container in sequence, and then flows out of the outlet housing from the second air flow channel.

[0011] Furthermore, the first end of the inlet shell is detachably connected to the intermediate shell, the first end of the inlet shell is provided with a clamping surface along the radial direction of the device, one end of the intermediate shell is also correspondingly provided with a clamping surface, and the aerosol filter layer is clamped and fixed between the two clamping surfaces.

[0012] Furthermore, the first end of the outlet shell is detachably connected to the intermediate shell, an adsorption container slot is provided in the cavity of the first end of the outlet shell, and the radioactive iodine adsorption container is detachably accommodated in the adsorption container slot.

[0013] Furthermore, a first connecting external thread is provided on the circumferential outer wall of the first end of the inlet shell, and a second connecting external thread is provided on the circumferential outer wall of the first end of the outlet shell. The first connecting external thread and the second connecting external thread are respectively fastened to the internal threads at both ends of the intermediate shell.

[0014] Furthermore, sealing rings are provided at the thread roots of the first connecting external thread and the thread roots of the second connecting external thread.

[0015] Furthermore, the second end of the inlet shell is an inlet connecting section, and an inlet internal thread is provided in the cavity at the inlet connecting section. The second end of the outlet shell is an outlet connecting section, and an outlet internal thread is provided in the cavity at the outlet connecting section.

[0016] Furthermore, the inlet shell further comprises an inlet main section and an inlet transition section, wherein the inlet transition section is located between the inlet connecting section and the inlet main section, and the outlet shell further comprises an outlet main section and an outlet transition section, wherein the outlet transition section is located between the outlet connecting section and the outlet main section.

[0017] Furthermore, knurled portions are provided on the circumferential outer walls of the inlet main body section, the outlet main body section and the intermediate shell.

[0018] Furthermore, the radioactive iodine adsorption container has an integrated shell, activated carbon is arranged in the shell, and both end surfaces of the radioactive iodine adsorption container have porous airflow channels.

[0019] In order to achieve the above-mentioned purpose, according to another aspect of the present invention, a nuclear power plant radioactive gas sampling system is proposed, including a sampling pipeline, wherein the sampling pipeline includes a sampling inlet pipe and a sampling outlet pipe, and also includes an adsorption sampling device for radioactive substances, one end of an inlet shell is detachably connected to the sampling inlet pipe, and one end of an outlet shell is detachably connected to the sampling outlet pipe.

[0020] By applying the technical solution of the present invention, at least the following beneficial effects are achieved:

[0021] 1. The adsorption sampling device of the present invention is configured as a three-section shell connection structure, and connected air flow channels are respectively provided, so that the structure of the device is compact and light, with fewer components, and is suitable for operation in a fume hood in a laboratory; by providing a porous third air flow channel, the air flow entering the radioactive iodine adsorption container is evenly dispersed, and the adsorption effect is better.

[0022] 2. The adsorption sampling device of the present invention is provided with a clamping surface and an adsorption container groove, so that the aerosol filter layer and the radioactive iodine adsorption container are separately packaged, which is convenient for taking them out separately, avoiding cross contamination and improving the test accuracy.

[0023] 3. The adsorption sampling device of the present invention is provided with an inlet internal thread and an outlet internal thread, which are respectively used to connect the sampling inlet pipe and the sampling outlet pipe in the radioactive gas sampling system of a nuclear power plant, so as to facilitate the installation and disassembly of the device.

[0024] 4. The adsorption sampling device of the present invention is convenient for manual disassembly and assembly through the threaded connection structure of the circumferential outer wall of each shell and the knurled part. By further arranging a sealing ring at the root of the thread, the internal sealing performance of the device is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 A schematic diagram of an adsorption sampling device according to an embodiment of the present invention is shown;

[0027] Figure 2 A top view of an adsorption sampling device according to an embodiment of the present invention is shown.

[0028] The above drawings include the following reference numerals:

[0029] 1. Inlet housing; 101. Inlet connecting section; 102. Inlet internal thread; 103. First connecting external thread; 104. Inlet main section; 105. Inlet transition section; 106. First air flow channel;

[0030] 2. Intermediate housing; 201. Third air flow channel;

[0031] 3. outlet shell; 301. adsorption container slot; 302. second connecting external thread; 303. outlet connecting section; 304. outlet internal thread; 305. outlet main section; 306. outlet transition section; 307. second air flow channel;

[0032] 4. Aerosol filter layer; 5. Radioactive iodine adsorption container; 6. Sealing ring; 7. Knurled part. DETAILED DESCRIPTION

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] The present invention is further described in detail below in conjunction with specific embodiments, and these embodiments cannot be understood as limiting the scope of protection claimed by the present invention. The term "including" when used indicates the existence of a feature, but does not exclude the existence or addition of one or more other features; the orientation or position relationship indicated by the terms "lateral", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0035] In the description, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0036] Example:

[0037] The present invention proposes a radioactive material adsorption sampling device, combined with Figure 1-Figure 2 As shown, it includes an inlet shell 1, an intermediate shell 2 and an outlet shell 3 connected in sequence. The inlet shell 1 and the outlet shell 3 both have a cavity structure with two ends connected, so that the inlet shell 1 has a first airflow channel 106 and the outlet shell 3 has a second airflow channel 307.

[0038] The middle shell 2 is provided with a porous third airflow channel 201, an aerosol filter layer 4 is provided between the inlet shell 1 and the middle shell 2, and a radioactive iodine adsorption container 5 is provided in the second airflow channel 307 of the outlet shell 3. The porous third airflow channel 201 allows the airflow entering the radioactive iodine adsorption container to be evenly dispersed, and the adsorption effect is better.

[0039] The gas flows into the first air flow channel 106 of the inlet housing 1, passes through the aerosol filter layer 4, the third air flow channel 201 and the radioactive iodine adsorption container 5 in sequence, and then flows out of the outlet housing 3 from the second air flow channel 307. The three-stage housing connection structure and the connected air flow channels are respectively provided, so that the structure of the device is compact and light, with fewer parts, and is suitable for operation in the fume hood of the laboratory.

[0040] Preferably, the aerosol filter layer 4 and the radioactive iodine adsorption container 5 are both independent components. The main function of the aerosol filter layer 4 is to filter out the aerosol and impurity particles in the test gas first, and also to prevent the downstream radioactive iodine adsorption container 5 from being blocked and ineffective due to impurities. The main function of the radioactive iodine adsorption container 5 is to adsorb the radioactive substance iodine in the test gas by chemical and physical means, further making the test gas cleaner.

[0041] Preferably, the radioactive iodine adsorption container 5 adopts a thin-walled integrated shell structure and is installed in the cavity of the outlet shell 3. Specially treated activated carbon is contained in the shell, and both end surfaces of the radioactive iodine adsorption container 5 have porous airflow channels.

[0042] The first end of the inlet housing 1 is detachably connected to the intermediate housing 2. Preferably, the first end of the inlet housing 1 is provided with a clamping surface along the radial direction of the device, and one end of the intermediate housing 2 is also correspondingly provided with a clamping surface, and the aerosol filter layer 4 is clamped and fixed between the two clamping surfaces. This facilitates the installation and removal of the aerosol filter layer 4.

[0043] The first end of the outlet housing 3 is detachably connected to the intermediate housing 2, and an adsorption container slot 301 is provided in the cavity of the first end of the outlet housing 3, and the radioactive iodine adsorption container 5 is detachably accommodated in the adsorption container slot 301. The aerosol filter layer and the radioactive iodine adsorption container are separately packaged, which is convenient for taking them out separately, avoiding cross contamination, and improving the accuracy of the test.

[0044] Furthermore, a first connecting external thread 103 is provided on the circumferential outer wall of the first end of the inlet shell 1, and a second connecting external thread 302 is provided on the circumferential outer wall of the first end of the outlet shell 3. The first connecting external thread 103 and the second connecting external thread 302 are respectively fastened to the internal threads at both ends of the intermediate shell 2.

[0045] A sealing ring 6 is installed at the thread root of the first connecting external thread 103, which is used for compression and sealing of the threaded connection between the inlet housing 1 and the intermediate housing 2. A sealing ring 6 is also provided at the thread root of the second connecting external thread 302, which is used for compression and sealing of the threaded connection between the outlet housing 3 and the intermediate housing 2, so that the internal sealing performance of the device is better.

[0046] Preferably, the inlet main body section 104, the outlet main body section 305 and the circumferential outer wall of the intermediate housing 2 are all provided with a knurled portion 7 to prevent slipping during manual disassembly and assembly, and facilitate manual disassembly and assembly of the device.

[0047] Furthermore, the second end of the inlet shell 1 is an inlet connection section 101, and an inlet internal thread 102 is provided in the cavity at the inlet connection section 101. The second end of the outlet shell 3 is an outlet connection section 303, and an outlet internal thread 304 is provided in the cavity at the outlet connection section 303. The inlet internal thread and the outlet internal thread are respectively used to connect the sampling inlet pipe and the sampling outlet pipe in the nuclear power plant radioactive gas sampling system, so as to facilitate the installation and disassembly of the device as a whole.

[0048] Furthermore, the inlet shell 1 also includes an inlet main section 104 and an inlet transition section 105 , wherein the inlet transition section 105 is located between the inlet connecting section 101 and the inlet main section 104 . The outlet shell 3 also includes an outlet main section 305 and an outlet transition section 306 , wherein the outlet transition section 306 is located between the outlet connecting section 303 and the outlet main section 305 .

[0049] Preferably, Figure 1 As shown, the circumferential outer walls of the inlet main section 104 and the inlet connecting section 101 are both cylindrical, and the outer diameter of the inlet main section 104 is larger than that of the inlet connecting section 101, and the circumferential outer wall of the inlet transition section 105 adopts a conical surface as a transition. The internal cavity of the inlet shell 1 matches the shape of the circumferential outer wall. The circumferential outer diameters of the inlet main section 104, the intermediate shell 2 and the outlet main section 305 are the same.

[0050] The present invention also proposes a nuclear power plant radioactive gas sampling system, including a sampling pipeline, the sampling pipeline including a sampling inlet pipeline and a sampling outlet pipeline, and also including the above-mentioned radioactive material adsorption sampling device, one end of the inlet shell 1 is detachably connected to the sampling inlet pipeline through the inlet internal thread 102, and one end of the outlet shell 3 is detachably connected to the sampling outlet pipeline through the outlet internal thread 304. Specifically, the adsorption sampling device of this embodiment is mainly used for collecting samples before the containment atmosphere and exhaust gas are discharged from the nuclear power plant, and is usually arranged on the sampling pipeline of the test system. The specific use steps are as follows:

[0051] The aerosol filter layer 4 and the radioactive iodine adsorption container 5 are packaged separately and can be used after being respectively loaded into a shell and connected to the system pipeline at the use site. In the installation step, check that all parts of the radioactive iodine adsorption sampling device are complete and have no defects in appearance; unscrew the three sections of the shell by hand and place them properly; carefully take out the aerosol filter layer 4 from the packaging box, check that there are no defects such as damage and wrinkles on the appearance, put it into the groove on the air inlet side of the intermediate shell 2 close to the clamping surface, and place it flat and without wrinkles; slowly screw the inlet shell 1 and the intermediate shell 2 together until the end surface fitting clearance of the two shells is less than 0.2 mm and it cannot be twisted by hand, and then the assembly is placed properly; carefully take out the radioactive iodine adsorption container 5 from the packaging box, check that there is no damage on the appearance, and put it into the adsorption container slot 301 in the outlet shell 3, and it should be noted that the airflow direction on the radioactive iodine adsorption container 5 is consistent with the airflow direction on the outlet shell 3; screw the outlet shell 3 with the radioactive iodine adsorption container 5 and the assembly together by hand; slowly screw the assembly and the outlet shell 3 together until the end surface fitting clearance of the two shells is less than 0.2 mm and it cannot be twisted by hand.

[0052] At this point, the assembly of the radioactive iodine adsorption sampling device is completed; the next step is to install the adsorption sampling device on the sampling pipeline; use tools to connect the sampling inlet pipeline with the inlet internal thread 102 of the adsorption sampling device, and connect the sampling outlet pipeline with the outlet internal thread 304 of the adsorption sampling device to ensure that the airtightness of the threaded connection is safe and reliable. After the installation is completed, the test operation is started according to the test process.

[0053] After the gas sampling operation is completed, in the dismantling step, use tools to remove the connecting threads at both ends of the sampling inlet pipe and the sampling outlet pipe and the adsorption sampling device, and remove the adsorption sampling device from the sampling pipeline; unscrew the connection between the outlet shell 3 and the intermediate shell 2 by hand, carefully take out the radioactive iodine adsorption container 5 and put it into the transport container; unscrew the threaded connection between the inlet shell 1 and the intermediate shell 2 by hand, carefully take out the aerosol filter layer 4 and put it into the transport container; clean and decontaminate the three-section shell; pre-assemble the three-section shell and seal it according to the test procedures (without installing the aerosol filter layer and the radioactive iodine adsorption container), waiting for the next sampling test.

[0054] In summary, from the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0055] 1. The adsorption sampling device of the present invention is configured as a three-section shell connection structure, and connected air flow channels are respectively provided, so that the structure of the device is compact and light, with fewer components, and is suitable for operation in a fume hood in a laboratory; by providing a porous third air flow channel, the air flow entering the radioactive iodine adsorption container is evenly dispersed, and the adsorption effect is better.

[0056] 2. The adsorption sampling device of the present invention is provided with a clamping surface and an adsorption container groove, so that the aerosol filter layer and the radioactive iodine adsorption container are separately packaged, which is convenient for taking them out separately, avoiding cross contamination and improving the test accuracy.

[0057] 3. The adsorption sampling device of the present invention is provided with an inlet internal thread and an outlet internal thread, which are respectively used to connect the sampling inlet pipe and the sampling outlet pipe in the radioactive gas sampling system of a nuclear power plant, so as to facilitate the installation and disassembly of the device.

[0058] 4. The adsorption sampling device of the present invention is convenient for manual disassembly and assembly through the threaded connection structure of the circumferential outer wall of each shell and the knurled part. By further arranging a sealing ring at the root of the thread, the internal sealing performance of the device is improved.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A radioactive material adsorption sampling device, characterized in that: The invention comprises an inlet shell (1), an intermediate shell (2) and an outlet shell (3) which are connected in sequence, wherein the inlet shell (1) and the outlet shell (3) both have a cavity structure with two ends connected, so that the inlet shell (1) has a first airflow channel (106) and the outlet shell (3) has a second airflow channel (307); the intermediate shell (2) is provided with a porous third airflow channel (201), an aerosol filter layer (4) is provided between the inlet shell (1) and the intermediate shell (2), and a radioactive iodine adsorption container (5) is provided in the second airflow channel (307) of the outlet shell (3); The gas flows into the first air flow channel (106) of the inlet housing (1), passes through the aerosol filter layer (4), the third air flow channel (201) and the radioactive iodine adsorption container (5) in sequence, and then flows out of the outlet housing (3) from the second air flow channel (307).

2. The adsorption sampling device according to claim 1, characterized in that: The first end of the inlet shell (1) is detachably connected to the intermediate shell (2); the first end of the inlet shell (1) is provided with a clamping surface along the radial direction of the device; one end of the intermediate shell (2) is also correspondingly provided with a clamping surface; the aerosol filter layer (4) is clamped and fixed between the two clamping surfaces.

3. The adsorption sampling device according to claim 2, characterized in that: The first end of the outlet shell (3) is detachably connected to the intermediate shell (2), and an adsorption container groove (301) is provided in the cavity of the first end of the outlet shell (3), and the radioactive iodine adsorption container (5) is detachably accommodated in the adsorption container groove (301).

4. The adsorption sampling device according to claim 3, characterized in that: A first connecting external thread (103) is provided on the circumferential outer wall of the first end of the inlet shell (1), and a second connecting external thread (302) is provided on the circumferential outer wall of the first end of the outlet shell (3), and the first connecting external thread (103) and the second connecting external thread (302) are respectively fastened to the internal threads at both ends of the intermediate shell (2).

5. The adsorption sampling device according to claim 4, characterized in that: The thread root of the first connecting external thread (103) and the thread root of the second connecting external thread (302) are both provided with sealing rings (6).

6. The adsorption sampling device according to any one of claims 3 to 5, characterized in that: The second end of the inlet shell (1) is an inlet connecting section (101), and an inlet internal thread (102) is provided in the cavity at the inlet connecting section (101); the second end of the outlet shell (3) is an outlet connecting section (303), and an outlet internal thread (304) is provided in the cavity at the outlet connecting section (303).

7. The adsorption sampling device according to claim 6, characterized in that: The inlet shell (1) further comprises an inlet main section (104) and an inlet transition section (105), wherein the inlet transition section (105) is located between the inlet connecting section (101) and the inlet main section (104); the outlet shell (3) further comprises an outlet main section (305) and an outlet transition section (306), wherein the outlet transition section (306) is located between the outlet connecting section (303) and the outlet main section (305).

8. The adsorption sampling device according to claim 7, characterized in that: The inlet main section (104), the outlet main section (305) and the circumferential outer wall of the intermediate shell (2) are all provided with a knurled portion (7).

9. The adsorption sampling device according to claim 1, characterized in that: The radioactive iodine adsorption container (5) has an integrated shell, activated carbon is arranged inside the shell, and both end surfaces of the radioactive iodine adsorption container (5) have porous airflow channels.

10. A nuclear power plant radioactive gas sampling system, characterized in that: The invention comprises a sampling pipeline, wherein the sampling pipeline comprises a sampling inlet pipe and a sampling outlet pipe, and further comprises an adsorption sampling device for radioactive substances according to any one of claims 1 to 9, wherein one end of an inlet shell (1) is detachably connected to the sampling inlet pipe, and one end of an outlet shell (3) is detachably connected to the sampling outlet pipe.

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