An online liquid scintillation degassing device and method

Abstract

The present invention discloses a degassing device and method for on-line liquid scintillation, which relates to the field of radioactive nuclide measurement. The device includes a degassing tank, a screen hole adsorption layer and a diaphragm pump. The inner cavity of the degassing tank is divided into a first area and a second area. The degassing tank is externally connected with a liquid inlet pipe communicating with the first area, and the degassing tank is externally connected with a film pipe communicating with the second area. The film pipe is used to connect with a scintillation liquid storage tank; the screen hole adsorption layer is arranged in the second area, and the air extraction end of the diaphragm pump is connected to the outer wall of the degassing tank and communicates with the first area; the first area is a vacuum area, and the second area is a solution area; the method is realized by using this device. The degassing device and method for on-line liquid scintillation provided by the present invention not only have the advantages of on-line measurement, are safer and more efficient during the radioactive substance test process, but also the impurity removal stage is carried out in categories and in sequence, and the purpose of high-efficiency impurity removal can be achieved in a short time, especially suitable for the scenario of on-line measurement of radioactive gas impurities.

Description

Technical Field

[0001] The present invention relates to the field of radionuclide measurement, and more particularly, to a degassing device and method for on-line liquid scintillation. Background Art

[0002] During the operation of reactors and nuclear power plants, it is necessary to monitor the operating status in real time to ensure their operating safety and the radiation safety of personnel and the public. Among them, the activity of tritium (H-3) is one of the nuclides to be monitored. Currently, there are mainly three types of tritium measurement methods, namely the scintillation method, the ionization chamber method, and the proportional counting method. The scintillation method is mainly used for the measurement of tritium in liquids due to its high sensitivity and low cost.

[0003] Currently, the scintillation method mainly adopts an off-line measurement method, sampling the loop water to the laboratory for analysis. Because there are many radioactive gas impurities in the loop water, such as 135 Xe, 85 Kr, 41 Ar, 131 I, 132 I and other radionuclides. These radioactive gas impurities have a great influence on the measurement results. By using methods such as opening to the air and standing for a long time, these gases undergo radioactive decay or natural volatilization to reduce their activity, thereby reducing the influence on the measurement results.

[0004] On the one hand, the above methods mainly rely on staff for manual sampling, which is prone to irradiation risks. At the same time, chemical toxic solutions are used during sample preparation, resulting in radioactive toxic solutions after measurement, which are difficult to handle. On the other hand, the timeliness of measurement is insufficient, and data cannot be obtained in a timely manner.

[0005] In view of this, the present application is specifically proposed. Summary of the Invention

[0006] The object of the present invention is to provide a degassing device and method for on-line liquid scintillation. By connecting a degassing tank and a membrane tube to a scintillation liquid storage tank, the device and method can realize on-line measurement of loop water, avoid irradiation risks and ensure the timeliness of data acquisition. At the same time, atomized spraying, adsorption and filtration are used to reduce the content of radioactive impurity gases in the loop water, thereby ensuring the accuracy of measurement results.

[0007] The embodiments of the present invention are implemented as follows:

[0008] In a first aspect, a degassing device for on-line liquid scintillation includes a degassing tank, a screen adsorption layer and a diaphragm pump. The inner cavity of the degassing tank is divided into a first region and a second region. The degassing tank is externally connected with a liquid inlet pipe communicating with the first region. One end of the liquid inlet pipe extends into the first region and is connected with an atomizing nozzle; the degassing tank is externally connected with a film tube communicating with the second region, and the film tube is used to connect with a scintillation liquid storage tank; the screen adsorption layer is arranged in the second region and divides the second region into two spaces communicating with each other through the screen holes; the air extraction end of the diaphragm pump is connected to the outer wall of the degassing tank and communicates with the first region; wherein, the first region is a vacuum region, the second region is a solution region, and the spraying direction of the atomizing nozzle is directly opposite to the solution region.

[0009] In an optional embodiment, a rotary stirring mechanism is arranged in the second region.

[0010] In an optional embodiment, a heating component for changing the temperature of the second region is arranged on the outer wall of the degassing tank.

[0011] In an optional embodiment, an air extraction pump is further included, and the air extraction end of the air extraction pump is communicated with the inner cavity of the film tube.

[0012] In an optional embodiment, the ratio of the caliber of the liquid inlet pipe to the aperture of the spray hole of the atomizing nozzle is: 50-200:1.

[0013] In an optional embodiment, the ratio of the height of the first region to the height of the second region is 2-5:1.

[0014] In a second aspect, a degassing method for on-line liquid scintillation is characterized in that the above-mentioned degassing device for on-line liquid scintillation is applied, and the method includes:

[0015] S1: Control the loop water to enter the liquid inlet pipe, and the loop water forms water mist under the action of the atomizing nozzle and is sprayed onto the liquid surface of the second region;

[0016] S2: Open the diaphragm pump, keep a negative pressure of 20-80 kPa in the first region, and keep the liquid surface of the second region 1-4 cm lower than the port of the air extraction end of the diaphragm pump;

[0017] S3: Use the screen adsorption layer to mix and adsorb the loop water entering the second region, and guide the loop water after the mixing and adsorption is completed to enter the film tube;

[0018] S4: Make a pressure difference between the inner cavity and the outer wall of the film tube, suck out the small molecule gas in the loop water entering the film tube, and send it into the scintillation liquid storage tank.

[0019] In an optional embodiment, in step S1, the loop water is controlled to enter the liquid inlet pipe with pressure, and the pressure range is 300-600 kPa.

[0020] In an alternative embodiment, in step S3, a sieve pore adsorption layer is used for mixed adsorption, and the temperature in the second region is controlled to be 60-90°C.

[0021] In an alternative embodiment, in step S4, the pressure difference ranges from 70 to 90 kPa.

[0022] The beneficial effects of the embodiments of the present invention are:

[0023] The degassing device for online liquid scintillation provided by the embodiments of the present invention is connected to the loop water pipeline through the liquid inlet pipe of the degassing tank and connected to the scintillation liquid storage tank through the material film tube, so as to directly incorporate the entire degassing device into the reactor loop system, achieving an online measurement method. Compared with the traditional offline measurement method, it has the advantages of avoiding radiation exposure to staff, easy treatment of the loop aqueous solution, and timely acquisition of measurement data. In addition, by setting an atomizing nozzle to preliminarily remove impurities from the loop aqueous solution, separating insoluble inert gases in the first region, adsorbing and removing soluble gases in the second region, and finally removing small molecule gases such as dissolved oxygen through the material film tube, effective removal of radioactive impurity gases in the loop water is achieved through sequential impurity removal in the above three stages, thereby ensuring high accuracy in the final tritium measurement.

[0024] The degassing method for online liquid scintillation provided by the embodiments of the present invention not only has the beneficial effects of the degassing device on the basis of applying the above degassing device, but also has reasonable and effective parameter control in each stage. It can obtain a good gas-liquid separation effect during the preliminary removal of insoluble inert gases, achieve a better removal efficiency of easily adsorbed gases such as iodine during the adsorption and removal of soluble gases, and finally filter the remaining small molecule gases in the loop aqueous solution. The three steps progress layer by layer, not only being able to scientifically and effectively remove various impurity gases in the loop water, but also being applied in the scenario of online measurement. This method can greatly ensure the impurity removal efficiency and ensure the implementation of the online detection activity of the tritium activity in water, thereby achieving the advantage of timely acquisition of data measurement results.

[0025] Generally speaking, the degassing device and method for online liquid scintillation provided by the embodiments of the present invention not only have the advantages of online measurement, being safer and more efficient during the radioactive substance test process, but also have classified and sequential impurity removal stages, with simple and efficient impurity removal effects, and are particularly suitable for the online measurement scenario of liquid scintillation containing radioactive impurity gases. Description of the Drawings

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0027] Figure 1 It is the schematic diagram of the structural composition of the degassing device provided by the embodiment of the present invention;

[0028] Figure 2 It is the schematic diagram of the structural composition of the degassing device provided by another embodiment of the present invention;

[0029] Figure 3 It is the main process schematic diagram of the degassing method provided by the embodiment of the present invention.

[0030] Icon: 1 - degassing tank; 2 - liquid inlet pipe; 3 - material film pipe; 4 - atomizing nozzle; 5 - diaphragm pump; 6 - air extraction pump; 7 - sieve hole adsorption layer; 8 - heating component; 11 - first area; 12 - second area. Detailed Embodiments

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, 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.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0035] Terms such as "substantially" and "essentially" are intended to indicate that the relevant content does not require absolute precision, but may have a certain deviation. For example: "substantially equal" does not merely mean absolute equality. Since it is difficult to achieve absolute "equality" during actual production and operation processes, there generally exists a certain deviation. Therefore, in addition to absolute equality, "substantially equal" also includes the situation of having a certain deviation as described above. Taking this as an example, in other cases, unless otherwise specified, terms such as "substantially" and "essentially" have meanings similar to the above.

[0036] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Embodiment 1

[0038] At present, the exhaust of domestic pressurized water reactors is mainly aimed at removing air from the primary loop water. For the chemical treatment of reactor water to remove radioactive gases in the reactor, the method of removing related nuclides by ion exchange is mainly used, but the exhaust effect is limited. The loop water of nuclear facilities exists in the loop of the reactor and is the medium for extracting the heat of the reactor. Especially the primary loop water of the reactor has strong radioactivity and contains very complex radioactive substances. When the reactor is in operation, the radioactive activity concentration of nuclides such as tritium in the loop water needs to be monitored to confirm the operating status of the reactor. When monitoring the tritium content in the reactor loop water, the main method used is offline measurement. This type of method requires personnel to be restricted to sampling the tritium-containing water in one loop, and then let it stand. On the one hand, it waits for the impurity gas in the water to undergo radioactive decay to reduce the content, and on the other hand, it uses the interface pressure difference between water and air to allow the impurity gas inside the water body to escape and reduce the content. The above method has the following problems: First, the radiation dose received by the staff during sampling is large, which affects radiation safety. Second, chemical toxic solutions are used during sample preparation, and after the measurement, the sample needs to be a radioactive toxic waste liquid, which is difficult to handle. Third, the measurement timeliness is insufficient and data cannot be obtained in time. To overcome the above problems, an embodiment of the present invention provides a degassing device for online liquid scintillator.

[0039] See also Figure 1 The present embodiment provides a degassing device for online liquid scintillator, comprising a degassing tank 1, a sieve adsorption layer 7 and a diaphragm pump 5. The degassing tank 1 is a tank body made of radiation-proof stainless steel, and has a liquid inlet, a liquid outlet and a plurality of exhaust ports. The inner cavity of the degassing tank 1 is divided into a first area 11 and a second area 12. In the usual use orientation, the first area 11 and the second area 12 are arranged vertically up and down. The degassing tank 1 is externally connected to a liquid inlet pipe 2 connected to the first area 11. One end of the liquid inlet pipe 2 extends into the first area 11 in the degassing tank 1 (which must be sealed) and is connected to an atomizing nozzle 4. The degassing tank 1 is externally connected to a material film tube 3 connected to the second area 12 (the connection between the material film tube 3 and the degassing tank 1 also needs to be sealed). The material film tube 3 is used to connect to a scintillation liquid storage tank, and scintillation liquid is stored in the scintillation liquid storage tank.

[0040] Through the above technical solutions, the basic structure for the on-line access and installation of the degassing device is realized. It is hermetically connected to the pipeline in the loop water system through the liquid inlet pipe 2, and the loop water to be measured (with a control valve) is introduced into the liquid inlet pipe 2 on-line for subsequent tritium measurement. The incoming loop water is atomized by the atomizing nozzle 4 and becomes in the form of droplets, and in this way, the insoluble gas in the loop water is initially separated from the gas-liquid. To achieve a further separation effect and effectively separate the soluble impurity gas, the sieve hole adsorption layer 7 is arranged in the second area 12, and the second area 12 is divided into two spaces that communicate with each other through the sieve holes. The loop water solution entering the second area must pass through the sieve hole adsorption layer 7 before entering the next link. The sieve hole adsorption layer 7 can adopt, for example, an activated carbon adsorption layer to effectively adsorb soluble gas impurities such as gaseous iodine and then enter the filter membrane tube 3 for filtration to achieve the purpose of removing small molecule gases.

[0041] In the above three-stage impurity removal process, to ensure the impurity removal efficiency of each stage, especially the earlier stage, the air extraction end of the diaphragm pump 5 is connected to the outer wall of the degassing tank 1 and communicates with the first area 11. On the one hand, this is to create a vacuum environment in the first area 11, and on the other hand, it is to provide negative pressure during the process of the loop water solution entering the second area 12 from the first area 11 to assist the escape of insoluble impurity gases. More importantly, the first area 11 is a vacuum area, the second area 12 is a solution area, and the spraying direction of the atomizing nozzle 4 is directly facing the solution area. Through the above technical solutions, when the loop water solution is sprayed from the atomizing nozzle 4 into the first area 11 to form a spray, most of the insoluble gases can be separated from the gas-liquid and thus be pumped away by the diaphragm pump 5. Since the spraying direction of the atomizing nozzle 4 is directly facing the liquid level surface of the solution area, the sprayed spray is pushed onto the liquid level surface under the action of force, and the surrounding is in a vacuum state, so the volume of the bubbles expands rapidly and explodes, thus achieving the purpose of removing excessive insoluble gases in the solution, and achieving a high-efficiency gas-liquid separation impurity removal efficiency in this first link. Especially during the on-line test process, the processing reliability of the previous link can reduce the complexity of the subsequent link and the deviation of the processing result.

[0042] Compared with the method of measuring tritium in loop water in an off-line manner, the degassing device provided by the embodiment of the present invention can not only effectively remove radioactive gases, adsorbable gases, and small molecule gases in the loop water, achieve the accuracy of the subsequent measurement results, and provide a structural guarantee for obtaining the data measurement results in a timely manner, but also can avoid the irradiation risk caused by manual sampling through automated operation, and there is no need to perform off-line treatment on the subsequent solution, which also reduces the irradiation risk from another aspect. In addition, compared with the traditional degassing method for nuclear facilities, which is mainly the degassing of the pressurizer, the volume of this degassing device can be made smaller, the liquid treatment volume can be controlled according to requirements, and the operation is simple and easy to control, so as to achieve the purpose of effectively monitoring the operation status of nuclear facilities in real time.

[0043] In addition, in the process of removing insoluble gas molecules, in order to achieve a better impurity removal effect, the ratio of the diameter of the liquid inlet pipe 2 to the aperture range of the spray holes of the atomizing nozzle 4 is: 50 - 200:1. For example, a design specification of 100:1 is adopted, so that when the circulating water enters, it will be more dispersed when falling by gravity, facilitating the escape of the internal gas. Similarly, considering that when the mist-like liquid is ejected, enough space should be given for the gas molecules to escape. The height range of the first region 11 is 50 - 120 cm, which can be selected according to specific requirements, so as to provide sufficient space conditions for the initial process of gas-liquid separation. After determining the height of the first region 11, the remaining space is provided for the second region 12 to determine the height of the second region 12. That is, in this embodiment, the ratio of the height of the first region to the height of the second region is 2 - 5:1. For example, 3:1, so as to achieve a relatively reasonable distribution space for the two regions.

[0044] Considering that in the first region 11, since the escape of insoluble gas molecules still needs to be achieved by hitting the liquid level surface of the second region 12 on the one hand, when the height ratio of the first region 11 to the second region 12 is too large (exceeding a certain limit), the effect of escape by impact will be weakened. Therefore, on the basis of determining the ratio of the diameter of the liquid inlet pipe 2 to the aperture range of the spray holes of the atomizing nozzle 4, the ratio of the height of the first region to the height of the second region is selected as 3:1, which can ensure that the mist-like liquid has sufficient gas separation conditions (under the synergistic action of the impact and negative pressure effects) on the one hand, and on the other hand, ensure that it has sufficient speed to impact the liquid level surface of the second region 12, so as to achieve the optimal gas-liquid separation effect. It should be noted that the negative pressure suction of the diaphragm pump 5 can accelerate the suction effect on the spray, and to a certain extent, it can assist the spray in impacting the liquid level surface of the second region 12. Therefore, when designing the above parameters, the effect of the working power of the diaphragm pump 5 is considered. For the negative pressure control in the first region 11, it can be achieved by configuring a pressure sensor to ensure the controllability of the pressure parameters and the safety of the test process.

[0045] In the process of removing soluble impurity gases, in order to ensure a certain timeliness, that is, to meet the requirements of online measurement timeliness, a rotary stirring mechanism (not shown) is provided in the second region 12. The purpose of this rotary stirring mechanism is to increase the effective contact rate between the circulating aqueous solution entering the second region 12 and the sieve hole adsorption layer 7, so as to achieve the purpose of fully adsorbing soluble impurity gases. Since the tritium-containing circulating aqueous solution entering the second region will gather at the bottom of the degassing tank 1, during this gathering process, the solution is rotated and stirred to achieve a more sufficient combination between the gas molecules and the adsorption material, and further remove easily adsorbed gases such as iodine.

[0046] In this embodiment, the integration method of the main driving part and the acting part of the rotary stirring mechanism, for example, the integration method of the driving motor and the stirring blade, the output shaft of the driving motor is connected to the central axis of the stirring blade, the stirring blade is arranged in the second region 12 of the degassing tank 1, and the rotary seal is carried out at the intersection of the central axis and the degassing tank 1, such as the sealing method of cooperating the bearing with the rubber ring or the bearing gas sealing method, etc. The arrangement method of the stirring blade can arrange part or all of the stirring blades in the second region 12 between the sieve hole adsorption layer 7 and the first region 11, and can disperse the circulating aqueous solution entering the second region 12 to achieve the purpose of high-speed movement of gas molecules, so as to achieve the purpose of further adsorption before passing through the sieve holes. It is also possible to arrange part of the stirring blade in the second region 12 between the sieve hole adsorption layer 7 and the first region 11, and arrange the other part in the second region 12 between the material film tube 3 and the sieve hole adsorption layer 7. The shaft body of the stirring blade passes through the sieve hole adsorption layer 7 (also using the rotary seal method), and the blades are located on both sides of the sieve hole adsorption layer 7, which can ensure the high-speed movement of gas molecules before and after the circulating aqueous solution passes through the sieve holes, so as to achieve a further adsorption purpose.

[0047] On the basis of the above embodiment or in the remaining embodiments, please refer to Figure 2 , a heating component 8 for changing the temperature of the second region 12 is provided on the outer wall of the degassing tank 1. The heating component 8 is mainly composed of a heating power supply and a heating resistance coil. The heating resistance coil can be wound around the outer wall of the degassing tank 1 to effectively cover or wrap the second region 12. The circulating aqueous solution entering the second region 12 can reduce the solubility of gas in water under the heating action at 60-90°C, for example, 80°C alone, to achieve the effect of accelerating the movement of gas molecules, thereby increasing the effective contact between gas molecules and the adsorption material, or the circulating water can achieve a better adsorption effect under the synergistic action of rotation and heating, and can significantly improve the removal efficiency of easily adsorbed gases such as iodine.

[0048] After the effective removal of insoluble gas molecules and soluble gas molecules, the circulating aqueous solution will contain some small-molecule gas impurities when entering the membrane tube 3. The membrane tube 4 is made of polytetrafluoroethylene polymer through special treatment and can achieve the purpose of effectively filtering small-molecule gases. On this basis, considering the timeliness of on-line measurement, in order to achieve a more efficient gas impurity removal effect for small-molecule gases, the degassing device further includes a suction pump 6. The suction end of the suction pump 6 is communicated with the inner cavity of the membrane tube 4, so that a greater pressure difference can be formed inside and outside the membrane tube 4, accelerating the process of filtering small-molecule gases from the inner cavity of the membrane tube 4 to the outer wall of the membrane tube 4, so as to meet the timeliness requirements of on-line measurement. It can be understood that the circulating water passes through the membrane tube 4, and in a vacuum negative pressure environment, excessive oxygen and other small-molecule gases in the circulating water are effectively removed. Finally, it is introduced into the three-way through the conduit and flows into the scintillation liquid storage tank and is mixed with the scintillation liquid, while the separated small-molecule gases are pumped out into the nuclear facility gaseous discharge flow loop. This process does not require the waste liquid treatment steps during off-line, which is safer and more reliable.

[0049] Generally speaking, the working principle of this degassing device is as follows: After the circulating water enters the liquid inlet pipe 2, under the action of gravity and / or pressure, it naturally flows downward and enters the degassing tank 1. It is pressurized by the atomizing nozzle 4 at the upper end of the degassing tank 1, so that the circulating aqueous solution (solution to be measured) spreads out in the form of a layered mist. Due to the pressure difference inside the system and in the degassing tank 1, the gases inside the solution to be measured instantly disperse and escape into the upper space of the degassing tank 1, and are pumped into the circulating gaseous discharge flow treatment system by the diaphragm pump 5. The liquid solution to be measured then falls into the second area 12 at the lower end. With the stirring and the rise of temperature, the solubility of gas in the liquid further decreases, and some bubbles rise from the bottom of the liquid and burst, and the gas is gradually released. In addition, for the following gases that are easy to adsorb, they will tightly adsorb on the screen adsorption layer 7, effectively removing gases with higher solubility in water such as iodine. The adsorbed solution to be measured passes through the membrane tube 3 in the vacuum chamber. Due to the pressure difference inside and outside the membrane tube 3, dissolved oxygen and other gases in the water will further escape and are directly discharged through the suction pump 6. Through the above three-stage impurity removal, all small-molecule gases such as inert gases with low solubility, adsorbable gases with high solubility, and dissolved oxygen inside the solution to be measured are removed, ensuring a relatively uniform radioactive solution and meeting the measurement requirements of on-line liquid scintillation.

[0050] Embodiment 2

[0051] Please refer to Figure 3, this embodiment provides a degassing method for on-line liquid scintillation, which applies the degassing device for on-line liquid scintillation in Embodiment 1. It should be noted that the degassing device for on-line liquid scintillation here refers to the minimum component technical solution of the on-line liquid scintillation degassing device that can achieve the purpose of "by connecting the degassing tank and the film tube to the scintillation liquid storage tank, on-line measurement of the loop water can be realized, the irradiation risk can be avoided while ensuring the timeliness of data acquisition, and at the same time, the content of radioactive impurity gases in the loop water can be reduced by means of atomized spraying, adsorption and filtration, so as to ensure the accuracy of the measurement results".

[0052] Specifically, the degassing method includes the following steps:

[0053] S1: Control the loop water to enter the liquid inlet pipe 2. Under the action of the atomizing nozzle 4, the loop water forms water mist and is sprayed onto the liquid surface of the second area 12. This step is mainly the basis for realizing the first-stage gas-liquid separation, enabling the loop water to form a spray first at the atomizing nozzle 4 and effectively separating the insoluble gas molecules during the process of impacting the liquid surface of the second area 12. Since there is generally a certain pressure in the loop during reactor operation, the reactor loop water can be directly led out by using the degassing device, or a pressurizing device can be arranged at the liquid inlet of the liquid inlet pipe 2. Under the action of pressure, the water will naturally flow into the liquid inlet pipe 2 and smoothly enter the degassing tank 1 through the atomizing nozzle 4 to achieve the purpose of fully forming a spray. That is to say, in this step S1, it is only necessary to control the loop water to enter the liquid inlet pipe 2 with pressure, which can be the pressure range that can be achieved in the original loop, or can be realized by adding a pressurizing device. The pressure range is 300 - 600 kPa. For example, in this embodiment, 500 kPa is adopted, so as to achieve the purpose of fully forming a spray and having a certain speed to impact the liquid level surface of the second area 12 as expected.

[0054] S2: Turn on the diaphragm pump 5. At this time, a micro-negative pressure system will be formed in the degassing tank 1, maintaining a negative pressure of 20 - 80 kPa, such as 50 kPa, in the first region 11. The gas escaping from the loop water will pass through the filter membrane of the diaphragm pump 5 and then be discharged through the pipeline into the reactor gaseous discharge flow system. During this process, keep the liquid level in the second region 12 1 - 4 cm, such as 2 cm, lower than the suction end port of the diaphragm pump 5. On the one hand, due to the continuous input of loop water, the liquid level surface in the second region 12 will continuously rise, thus affecting the impact distance between the spray and the liquid level surface, and instead reducing the separation effect of poorly soluble gases. Therefore, it is necessary to control the discharge of the solution in the second region to ensure the stability of its liquid level height. Among them, the discharge method can be achieved, for example, by discharging through the material film tube 3, or by setting up another drainage pipeline. This drainage pipeline is connected to the solution buffer container, and the solution temporarily stored in the solution buffer container to control the liquid level height can be compensated back into the inlet pipe 2 by means of pump suction. On the other hand, the spray impact on the liquid level surface makes the escape effect of poorly soluble gas molecules better. At this time, arranging the suction end of the diaphragm pump 5 near the liquid level surface can achieve a more effective suction effect on the escaping gas molecules, and can also accelerate the possibility of poorly soluble gas molecules escaping during the impact, ensuring a higher separation efficiency of poorly soluble gas molecules.

[0055] S3: Use the sieve pore adsorption layer 7 to mix and adsorb the loop water entering the second region 12, and guide the loop water after the completion of the mixed adsorption into the material film tube 3. Through the sieve pore adsorption layer 7, the soluble gas molecules can be effectively adsorbed. And in order to achieve a better adsorption effect during this process, in some embodiments, when using the sieve pore adsorption layer 7 for mixed adsorption, control the temperature in the second region 12 to be 60 - 90 °C, such as 80 °C. The increase in temperature can reduce the solubility of gas in water and accelerate the movement of gas molecules, thereby improving the mixed adsorption effect. The heating method can use electric heating, for example, by passing an electric current through the heating coil to transfer heat to the second region 12. In addition, on this basis or in other embodiments, a stirring mechanism can also be set in the second region 12 to accelerate the thermal movement of liquid molecules and gas molecules, achieving the purpose of continuous contact with activated carbon, and removing gases with strong adsorption such as iodine and solid particle impurities.

[0056] S4: Create a pressure difference between the inner cavity and the outer wall of the material film tube 3, suck out the small molecule gas in the loop water entering the material film tube 3, and send it to the scintillation liquid storage tank. In this step S4, the range of the pressure difference is 70 - 90 kPa, such as 80 kPa, so that under the action of this negative pressure, some small molecule gases escape again, obtaining a purer liquid to be measured.

[0057] Through the above technical solutions, the liquid to be measured is fully purified, so as to facilitate obtaining reliable measurement results. The sample solution for measurement generally refers to the solution to be measured containing impurity gases, such as the primary and secondary circuit waters of a reactor, etc. Generally, the activity concentration of the unknown solution to be measured is unknown and variable. When it is necessary to know the activity of the sample solution to be measured at a certain moment, the degassing device and the degassing method can be connected to the solution to be measured for measurement.

[0058] The above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. It should be noted that the structures or components illustrated in the drawings are not necessarily drawn to scale, and the present invention omits the description of well-known components and processing techniques and processes to avoid unnecessarily limiting the present invention.

Claims

1. An online liquid scintillation degassing device, characterized in that, Comprising: A degassing tank, the inner cavity of the degassing tank is divided into a first area and a second area, the degassing tank is externally connected with a liquid inlet pipe communicating with the first area, one end of the liquid inlet pipe extends into the first area and is connected with an atomizing nozzle, and the liquid inlet pipe is used for introducing pressurized loop water into the degassing tank; the degassing tank is externally connected with a film pipe communicating with the second area, and the film pipe is used for connecting with a scintillation liquid storage tank; A sieve hole adsorption layer, the sieve hole adsorption layer is arranged in the second area and divides the second area into two spaces communicating with each other through sieve holes; A diaphragm pump, the air extraction end of the diaphragm pump is connected to the outer wall of the degassing tank and communicates with the first area; Wherein, the first area is a vacuum area, the second area is a solution area, and the spraying direction of the atomizing nozzle is directly opposite to the solution area.

2. The degassing device for on-line liquid scintillation according to claim 1, characterized in that, A rotary stirring mechanism is arranged in the second area.

3. The degassing device for on-line liquid scintillation according to claim 1 or 2, characterized in that, A heating component for changing the temperature of the second area is arranged on the outer wall of the degassing tank.

4. The degassing device for on-line liquid scintillation according to claim 1, characterized in that, It further includes an air extraction pump, and the air extraction end of the air extraction pump communicates with the inner cavity of the film pipe.

5. The degassing device for on-line liquid scintillation according to claim 1, characterized in that, The ratio of the caliber of the liquid inlet pipe to the aperture of the spray hole of the atomizing nozzle is: 50-200:

1.

6. The degassing device for on-line liquid scintillation according to claim 1 or 5, characterized in that, The ratio of the height of the first area to the height of the second area is 2-5:

1.

7. A degassing method for on-line liquid scintillation, characterized in that, Applying the degassing device for online liquid scintillation according to any one of claims 1-6, the method includes: S1: Control the pressurized loop water to enter the liquid inlet pipe, and the pressurized loop water forms water mist under the action of the atomizing nozzle and sprays to the liquid level in the second area; S2: Open the diaphragm pump, keep a negative pressure of 20-80 kPa in the first area, and keep the liquid level in the second area 1-4 cm lower than the port of the air extraction end of the diaphragm pump; S3: Use the sieve hole adsorption layer to mix and adsorb the loop water entering the second area, and guide the loop water after the completion of the mixing adsorption to enter the film pipe; S4: Make a pressure difference be formed between the inner cavity and the outer wall of the film pipe, suck out the small molecule gas in the loop water entering the film pipe, and then send it into the scintillation liquid storage tank.

8. The degassing method for online liquid scintillation according to claim 7, characterized in that, In the step S1, control the loop water to enter the liquid inlet pipe with pressure, and the pressure range is 300-600 kPa.

9. The degassing method for on-line liquid scintillation according to claim 7, characterized in that, In the step S3, use the sieve hole adsorption layer for mixing adsorption, and control the temperature in the second area to be 60-90 °C.

10. The degassing method for on-line liquid scintillation according to claim 7, characterized in that, In the step S4, the range of the pressure difference is 70-90 kPa.

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