A leak detection device and method for iodine-125 extraction device

Abstract

The present invention discloses a leak detection device and method for an iodine-125 extraction device, and belongs to the technical field of radioisotope equipment. It includes: a base plate and a leak detection mechanism installed on the base plate; the leak detection mechanism includes: a hand-turned valve, a barometer and a gas detection seat that are detachably connected to each other; the hand-turned valve is installed on the base plate through a gas valve seat; an iodine-125 extraction device is installed on the gas detection seat; two leak detection gas nozzles are also provided on the gas detection seat, and the two leak detection gas nozzles are respectively connected to the column nozzles on the iodine-125 extraction device. The leak detection device for an iodine-125 extraction device provided by the present invention can ensure the requirements of the leakage rate of an iodine-125 loop device in the production process. The use of the leak detection device can avoid the loss of expensive gas and the release of radioactive gas, improve work efficiency, reduce radioactive operation time, and reduce radiation damage to workers.

Description

Technical Field

[0001] The invention relates to the technical field of radioisotope preparation, and in particular to a leak detection device and method for an iodine-125 extraction device, and is particularly suitable for rapid leak detection of an iodine-125 extraction device in an iodine-125 irradiation production loop of a continuous circulation loop method. Background Art

[0002] Iodine-125 is an important medical radionuclide. It has a long half-life, moderate energy, and little radiation damage to human tissue, making it widely used in biomedicine, radioimmunoassay in vitro diagnosis, and close-range implantation for tumor treatment. However, the raw materials of iodine-125 in China have long been completely dependent on imports.

[0003] At present, taking advantage of the reactor and supporting resources, China Nuclear Power Research and Design Institute has completed a large number of experimental verifications and proposed a technical method and device for producing iodine-125 by continuous cycle irradiation. This method innovatively designs a quick-pluggable iodine-125 extraction device in the loop device. The use of this device prevents the iodine-125 produced in the loop from continuing to circulate into the reactor active area and being converted into iodine-126 impurities by irradiation, thereby reducing the iodine-126 content to the greatest extent, improving the quality of iodine-125, and also increasing the reuse rate of xenon-124 gas. In addition, compared with traditional methods, the design and use of this device reduces the transfer of xenon-125 gas, xenon-125 decay, liquid nitrogen freezing, target tube cutting, alkali solution leaching and extraction processes required by traditional methods, greatly simplifying the process flow and reducing costs.

[0004] In order to facilitate the replacement of the adsorbent in the adsorption column core in the iodine-125 extraction device and the quick plugging and unplugging from the iodine-125 gas circuit, the patent number is CN202110697116.5, and the patent name is a device for extracting gaseous iodine in the preparation of iodine-125 by loop method. The extraction device is designed with four detachable structures, namely the screw sleeves at both ends of the extraction column and the gas nozzles connected to both ends of the loop. During long-term repeated use, there may be a risk of gas leakage at the four detachable and assembled structural points due to operation and wear. Moreover, when the extraction device is installed in the gas circuit of the continuous circulation loop method for irradiation production of iodine-125, the air tightness of the circuit is high, and the circuit is filled with radioactive gas medium. If the circuit is found to be leaking after the extraction device is installed, it will not only lead to the loss of important and expensive gases in the gas circuit, but also cause the leakage of radioactive gas, causing radiation damage to the staff. In addition, the extraction device circuit is used for irradiation production of iodine-125. Due to the special chemical properties of iodine, it is required that no water, oil or other impurities should be introduced into the circuit during each leak detection and installation of the extraction device.

[0005] Based on the above considerations, it is urgently necessary to design a simple and quick leak detection device for the iodine-125 extraction device to ensure that the four detachable structures in the assembled extraction device do not leak, thereby ensuring that the extraction device does not leak after being installed in the loop. In addition, impurities such as water and oil cannot be introduced during the leak detection process of the extraction device. Summary of the invention

[0006] The purpose of the present invention is to provide a leak detection device and method for an iodine-125 extraction device, so as to solve the problem that the screw sleeves at both ends of the extraction column and the gas nozzles connected to both ends of the loop in the existing iodine-125 extraction device may cause the risk of gas leakage at four detachable and assembled structural points due to operation and wear during long-term repeated use. The purpose of ensuring that the gaseous iodine-125 extraction device has good air tightness after each assembly, so that the overall air tightness is good after being installed in the iodine-125 loop, and at the same time, impurities such as water and oil are not introduced into the loop device, thereby reducing the radiation time of personnel, improving work efficiency, and saving working time.

[0007] The technical solution of the present invention to solve the above technical problems is as follows:

[0008] The present invention provides a leak detection device for an iodine-125 extraction device, comprising: a bottom plate and a leak detection mechanism installed on the bottom plate;

[0009] The leak detection mechanism comprises: a hand-operated valve, a pressure gauge and a gas detection seat which are detachably connected to each other; the hand-operated valve is mounted on the bottom plate through the gas valve seat; an iodine-125 extraction device is mounted on the gas detection seat;

[0010] The gas detection seat is also provided with two leak detection gas nozzles, and the two leak detection gas nozzles are respectively connected to the column nozzles on the iodine-125 extraction device.

[0011] Furthermore, in the leak detection device for the iodine-125 extraction device, a fixing mechanism is also installed on the base plate, and the fixing mechanism includes: a support and a quick clamp for fixing the iodine-125 extraction device, the support is installed on the base plate, and the quick clamp is fixed on the support.

[0012] Furthermore, in the leak detection device for the iodine-125 extraction device, a flat gasket is provided between the support and the quick clamp.

[0013] Furthermore, in the leak detection device for the iodine-125 extraction device, an elastic gasket is provided between the support and the quick clamp, and the elastic gasket is located above the flat gasket.

[0014] Furthermore, in the leak detection device for the iodine-125 extraction device, handles are respectively installed on both sides of the bottom plate.

[0015] Furthermore, in the leak detection device for the iodine-125 extraction device, the hand valve, the pressure gauge and the gas detection seat are connected through a three-way joint.

[0016] Furthermore, in the leak detection device for the iodine-125 extraction device, the hand-turned valve is also connected to an inert gas cylinder.

[0017] Furthermore, in the leak detection device for the iodine-125 extraction device, a muffler is connected to the leak detection gas nozzle.

[0018] Furthermore, in the leak detection device for the iodine-125 extraction device, a sign for marking identification is provided on the bottom plate.

[0019] The present invention also provides a leak detection method for an iodine-125 extraction device, based on the above-mentioned leak detection device for an iodine-125 extraction device, comprising the following steps:

[0020] After installing the iodine-125 extraction device on the leak detection device, turn the hand valve to the pressurization gear, fill the leak detection device with inert gas, and when the pressure gauge reaches the preset setting value, turn the hand valve to the pressure maintaining gear and stop filling with gas; after the pressure value of the pressure gauge stably maintains the preset setting value for at least 30 minutes, release the pressure through the hand valve and discharge the gas.

[0021] The present invention has the following beneficial effects:

[0022] The leak detection device for an iodine-125 extraction device provided by the present invention can ensure the requirements for the leakage rate of the iodine-125 loop device in the production process, ensure the good air tightness of the iodine-125 extraction device after being installed in the loop, avoid the loss of expensive xenon-124 gas in the loop due to the presence of a leak in the extraction device; avoid the leakage of radioactive gas in the loop due to the presence of a leak in the extraction device. At the same time, it avoids repeated operations due to the presence of a leak in the extraction device, thereby improving work efficiency, reducing radioactive operation time, and reducing radiation damage to workers; at the same time, it avoids the possibility of the iodine-125 extraction device introducing impurities such as water and oil into the loop device during the leak detection and installation process, and ensures the quality of the iodine-125 product.

[0023] The leak detection device for an iodine-125 extraction device provided by the present invention is an independent structure, which is installed on the leak detection device before being installed in a loop for producing iodine-125 for pressure-maintaining leak detection, and the pressure-maintaining time is at least 30 minutes, and the pressure is stable, which proves that the four detachable structural positions of the extraction device have good air tightness, thereby ensuring that the overall air tightness is good after it is installed in the loop, and in addition, the leak detection method will not introduce impurities such as water and oil into the extraction device, thereby ensuring the quality of the iodine-125 product in the loop. The use of the leak detection device can greatly improve work efficiency, reduce radioactive working time, and reduce the radiation time of the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0025] Figure 1 It is a front view structural schematic diagram of the leak detection device for an iodine-125 extraction device of the present invention;

[0026] Figure 2 It is a side structural schematic diagram of the leak detection device for an iodine-125 extraction device of the present invention;

[0027] Figure 3 It is a schematic diagram of the top view of the structure of the leak detection device for the iodine-125 extraction device of the present invention;

[0028] Figure 4 The present invention is a schematic diagram of the bottom structure of the leak detection device for the iodine-125 extraction device.

[0029] In the figure: 10-bottom plate, 11-handle, 12-label, 21-hand valve, 22-pressure gauge, 23-gas detection seat, 24-gas valve seat, 25-leak detection nozzle, 26-three-way connector, 27-muffler, 28-welded straight pipe connector, 29-quick plug connector, 31-support, 32-quick clamp, 33-flat washer, 34-elastic washer, 40-extraction device. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] The embodiment of the present invention provides a leak detection device for an iodine-125 extraction device, which is suitable for rapid leak detection of an iodine-125 extraction device that produces iodine-125 by continuous cycle irradiation. That is, the device for extracting gaseous iodine in the preparation of iodine-125 by loop method is designed with four detachable structures, namely, the screw sleeves at both ends of the extraction column and the gas nozzles connected to both ends of the loop. During long-term repeated use, there may be a risk of gas leakage at the four detachable and assembled structural points due to operation and wear. An independent leak detection device is designed, the leak detection device is installed on the extraction device, an inert gas is injected into the leak detection device, and the extraction device is subjected to gas pressure maintenance detection, thereby achieving rapid leak detection of the extraction device.

[0034] Please refer to Figure 1-4 An embodiment of the present invention provides a leak detection device for an iodine-125 extraction device, including a base plate 10 and a leak detection mechanism, wherein the leak detection mechanism is installed on the base plate 10.

[0035] The base plate 10 is used for integrating and fixing the components of the leak detection device. Handles 11 are installed on both sides of the base plate 10, and the transfer and transportation of the leak detection device are completed by the handles 11. It is convenient to use and easy to operate. Specifically, the two ends of the handle 11 are fixed to the base plate 10 by hexagon socket head screws, which is convenient for installation and disassembly. In other embodiments of the present invention, the hexagon socket head screws can also be replaced by bolts and other fixings. A sign 12 for identification is provided on the base plate 10, which is used to record relevant information of the leak detection device.

[0036] The leak detection mechanism includes: a hand-turned valve 21, a pressure gauge 22 and a gas detection seat 23 which are interconnected. The hand-turned valve 21, the pressure gauge 22 and the gas detection seat 23 are detachably connected, which is convenient for installation and disassembly and easy to carry. The gas detection seat 23 is installed on the base plate 10, and the hand-turned valve 21 is installed on the base plate 10 through the gas valve seat 24, which is convenient for installation and disassembly of the hand-turned valve 21. In this embodiment, the gas valve seat 24 is fixed to the base plate 10 by a hexagon socket head screw, which is convenient for installation and disassembly. In other embodiments of the present invention, the hexagon socket head screw can also be replaced by a fixing member such as a bolt.

[0037] The barometer 22 is located between the hand-turned valve 21 and the gas detection seat 23, and the barometer 22 is connected to both of them, and the hand-turned valve 21 and the gas detection seat 23 are also connected. Among them, the hand-turned valve 21 injects or discharges gas into the gas passage between the hand-turned valve 21 and the extraction device 40 by controlling its gear position. In the present embodiment, the hand-turned valve 21 is in manual control mode, which is convenient for operation during leak detection. In the present embodiment, the hand-turned valve 21 is connected to an inert gas cylinder. Specifically, the hand-turned valve 21 is connected to the inert gas cylinder through a quick-plug connector 29, and the quick-plug connector 29 can realize the quick connection between the hand-turned valve 21 and the inert gas cylinder. The inert gas cylinder is filled with inert gases such as air and nitrogen to provide a pressure source, and other impurity gases will not be introduced to cause adverse effects on the extraction device 40.

[0038] In a feasible implementation scheme, the hand-turned valve 21, the pressure gauge 22 and the gas detection seat 23 are connected through a three-way joint 26, and the hand-turned valve 21, the pressure gauge 22 and the gas detection seat 23 are detachably installed through the connection of the three-way joint 26. In this embodiment, the hand-turned valve 21 and the three-way joint 26 are connected through a welded straight pipe joint 28 and fixed by a hexagon socket head screw. A hexagon socket plug is provided at the outlet of the hand-turned valve 21 for blocking the hand-turned valve 21.

[0039] Barometer 22 is used for monitoring the pressure value of the pressure-maintaining device 40, and the range of barometer 22 is 0-0.6 Mpa, and the minimum scale is 5Kpa. Gas detection seat 23 is used for installing the extraction device 40. An iodine-125 extraction device 40 is installed on the gas detection seat 23, and the extraction device 40, the gas detection seat 23, the barometer 22 and the hand-turned valve 21 can form a connected gas path, and the inert gas entering from the hand-turned valve 21 circulates in the gas path, and the pressurization and pressure-maintaining operations are realized by the hand-turned valve 21, and the leak detection operation is completed with reference to the numerical value of the pressure gauge. Two leak detection gas nozzles 25 are also provided on the gas detection seat 23, and the two leak detection gas nozzles 25 are respectively connected with the column nozzle on the iodine-125 extraction device 40. In the present embodiment, the inner diameter of the leak detection gas nozzle 25 is 2-4cm, and the gas entry speed is controlled by controlling the inner diameter size of the leak detection gas nozzle 25 to control the leak detection operation in a reasonable and accurate manner.

[0040] In a feasible implementation, during the pressure relief and exhaust process, the leak detection nozzle 25 can be used as a silencer, and the leak detection nozzle 25 is connected to a silencer 27 for eliminating the exhaust sound.

[0041] In a feasible implementation scheme, a fixing mechanism is also installed on the base plate 10, and the fixing mechanism includes: a support 31 and a quick clamp 32. The support 31 is installed on the base plate 10. In this embodiment, the support 31 is fixed to the base plate 10 by a hexagon socket head screw, which is convenient for installation and disassembly. In other embodiments of the present invention, the hexagon socket head screw can also be replaced by a bolt or other fixing part. The quick clamp 32 is fixed on the support 31. The quick clamp 32 is used to fix and protect the extraction column during the pressure holding process to prevent the extraction device 40 from being squeezed out by the air pressure due to excessive pressure during the inflation process. A flat washer 33 is also provided between the support 31 and the quick clamp 32, and an elastic washer 34 is also provided between the support 31 and the quick clamp 32, and the elastic washer 34 is located above the flat washer 33. The flat washer 33 and the elastic washer 34 are used to improve the stability of the support 31 and the quick clamp 32.

[0042] In a feasible implementation scheme, the base plate 10, the three-way connector 26, the gas inspection seat 23, the handle 11, the quick clamp 32, the support 31, the gas valve seat 24, the welded straight pipe connector 28, and the nameplate 12 are all made of stainless steel, which is wear-resistant and has a long service life.

[0043] The leak detection device of the embodiment of the present invention is an independent structure. The adsorption device can be quickly inserted and removed from the leak detection device. After installation, rapid leak detection can be performed by filling inert gas.

[0044] Example 2

[0045] Please refer to Figure 1-4 This embodiment also provides a leak detection method for an iodine-125 extraction device, based on the above-mentioned leak detection device for an iodine-125 extraction device, comprising the following steps:

[0046] After installing the iodine-125 extraction device on the leak detection device, turn the hand valve to the pressurization gear, fill the leak detection device with inert gas, and when the pressure gauge reaches the preset setting value, turn the hand valve to the pressure maintaining gear and stop filling with gas; after the pressure value of the pressure gauge has been stably maintained at the preset setting value for at least 30 minutes, release the pressure through the hand valve and discharge the gas.

[0047] Specifically, firstly, after the whole set of leak detection device is assembled, the extraction device is installed on the leak detection device.

[0048] Connect the quick-connect connector to the air pipe of the pressure reducing valve of the inert gas cylinder, slowly open the pressure reducing valve of the gas cylinder, open the valve of the hand-turn valve to the pressurization position, and allow the gas to slowly fill the passage between the hand-turn valve and the extraction device.

[0049] When the pressure value on the pressure gauge reaches 0.4-0.6Mpa, open the hand valve to the pressure-maintaining position, maintain the pressure between the hand valve and the extraction device, close the pressure reducing valve and main valve of the inert gas cylinder, and unplug the air pipe connected to the quick-connect connector.

[0050] After the pressure gauge has been stably maintained at 0.4-0.6Mpa for at least 30 minutes, open the hand valve to the pressure relief position to discharge the gas between the hand valve and the extraction device, remove the extraction device, and complete the pressure maintenance.

[0051] The leak detection device of the present invention is an independent structure. Before being installed in a loop for producing iodine-125, it is installed on the leak detection device for pressure-maintaining leak detection. The pressure-maintaining time is at least 30 minutes. If the pressure is stable, it proves that the four detachable structural positions of the extraction device have good air tightness, thereby ensuring that the overall air tightness is good after the extraction device is installed in the loop. In addition, the leak detection method will not introduce impurities such as water and oil into the extraction device, thereby ensuring the quality of the iodine-125 product in the loop.

[0052] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A leak detection device for an iodine-125 extraction device, characterized in that: include: A bottom plate (10) and a leak detection mechanism mounted on the bottom plate (10); The leak detection mechanism comprises: a hand-operated valve (21), a pressure gauge (22) and a gas detection seat (23) which are detachably connected to each other; the hand-operated valve (21) is mounted on the bottom plate (10) via a gas valve seat (24); an iodine-125 extraction device is mounted on the gas detection seat (23); The gas detection seat (23) is also provided with two leak detection gas nozzles (25), and the two leak detection gas nozzles (25) are respectively connected to the column nozzles on the iodine-125 extraction device; The iodine-125 extraction device is designed with four detachable structures, namely the screw sleeves at both ends of the extraction column and the gas nozzles connected to both ends of the loop; Before installing it in the circuit for producing iodine-125, install it on the leak detection device for pressure-maintaining leak detection. The pressure-maintaining time is at least 30 minutes. If the pressure is stable, it proves that the four detachable structural positions of the extraction device have good air tightness.

2. The leak detection device for iodine-125 extraction device according to claim 1, characterized in that: A fixing mechanism is also mounted on the bottom plate (10), the fixing mechanism comprising: a support (31) and a quick clamp (32) for fixing the iodine-125 extraction device, the support (31) being mounted on the bottom plate (10), and the quick clamp (32) being fixed on the support (31).

3. The leak detection device for iodine-125 extraction device according to claim 2, characterized in that: A flat washer (33) is also provided between the support (31) and the quick clamp (32).

4. The leak detection device for iodine-125 extraction device according to claim 3, characterized in that: An elastic washer (34) is also provided between the support (31) and the quick clamp (32), and the elastic washer (34) is located above the flat washer (33).

5. The leak detection device for iodine-125 extraction device according to claim 1, characterized in that: Handles (11) are respectively installed on both sides of the bottom plate (10).

6. The leak detection device for an iodine-125 extraction device according to claim 1, characterized in that: The hand-operated valve (21), the pressure gauge (22) and the gas detection seat (23) are connected via a three-way joint (26).

7. The leak detection device for an iodine-125 extraction device according to claim 1, characterized in that: The hand-operated valve (21) is also connected to an inert gas cylinder.

8. The leak detection device for an iodine-125 extraction device according to any one of claims 1 to 7, characterized in that: The leak detection air nozzle (25) is connected to a muffler (27).

9. The leak detection device for an iodine-125 extraction device according to claim 8, characterized in that: The bottom plate (10) is provided with a sign (12) for logo identification.

10. A leak detection method for an iodine-125 extraction device, characterized in that: The leak detection device for an iodine-125 extraction device according to any one of claims 1 to 9 comprises the following steps: After installing the iodine-125 extraction device on the leak detection device, pressurize it through the manual valve and fill the leak detection device with inert gas. When the pressure gauge reaches the preset setting value, maintain the pressure through the manual valve and stop filling the gas. After the pressure value of the pressure gauge has been stably maintained at the preset setting value for at least 30 minutes, release the pressure through the manual valve and discharge the gas.

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