Online monitoring device for multiple nuclides in liquid effluent

Abstract

The invention provides an online monitoring device for multiple nuclides in liquid effluent, and particularly relates to the technical field of radioactive substance detection. The online monitoring device comprises a shell, a cascade separation module, a fluid control module, a detection module and a control system, the cascade separation module, the detection module and the control system are arranged in the shell, the cascade separation module comprises a plurality of resin columns and a plurality of separated liquid collecting bottles communicated with the resin columns, and the separated liquid collecting bottles are communicated with the resin columns. The fluid control module comprises a liquid storage device, an injection pump and a control valve, the liquid storage device is respectively communicated with the plurality of resin columns through pipelines, the injection pump and the control valve are respectively arranged on the pipelines and are used for controlling the flow direction and the flow velocity of fluid in the liquid storage device, and the detection module is used for detecting the radioactive activity of nuclide; the control system is used for controlling operation of the cascade separation module, the fluid control module and the detection module. According to the invention, synchronous monitoring of multiple nuclides is realized, the multi-nuclide monitoring efficiency is improved, and the monitoring cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of radioactive material detection technology, and in particular to an online monitoring device for multiple nuclides in liquid effluents. Background Technology

[0002] The operation of nuclear power plants and other nuclear facilities involves the release of radioactive materials, which enter the environment through liquid and gaseous effluents, posing a radiation risk to the public. Therefore, assessing the radioactive emissions in the effluents of nuclear power plants and other nuclear facilities is a primary task in radioactive waste management and environmental protection. Among the liquid effluents from nuclear power plants, Fe-55, Ni-63, Sr-89, and Sr-90 are radionuclides requiring close monitoring. However, these nuclides are all pure beta nuclides, which cannot be monitored using conventional gamma spectroscopy methods. Complex radiochemical separation processes are required, followed by measurement on a liquid scintillation spectrometer or beta counter. This analytical process is lengthy and complex, often requiring several days to obtain results. The complex analytical procedures often affect the implementation of emissions, potentially causing adverse effects on the production and operation of nuclear power plants.

[0003] Therefore, developing an online monitoring device for difficult-to-detect nuclides in liquid effluents to replace the lengthy and complex method of manual analysis in the laboratory after sampling, and to implement rapid and efficient automatic monitoring, has become a problem that the nuclear power industry must solve. Summary of the Invention

[0004] This invention provides an online monitoring device for multiple nuclides in liquid effluents to solve the technical problems of low detection efficiency and high manpower and material costs in existing technologies.

[0005] This invention provides an online monitoring device for multiple nuclides in liquid effluents. The online monitoring device includes: a shell, a cascade separation module, a fluid control module, a detection module, and a control system. The cascade separation module is disposed within the shell and includes multiple resin columns for adsorbing nuclides and multiple separation liquid collection bottles connected to the resin columns. The fluid control module includes a liquid storage device, an injection pump, and a control valve. The liquid storage device is connected to the multiple resin columns via pipelines. The injection pump and the control valve are respectively disposed on the pipelines and are used to control the flow direction and flow rate of the fluid in the liquid storage device. The detection module is used to detect the radioactivity of the nuclides. The control system is disposed within the shell and is used to control the operation of the cascade separation module, the fluid control module, and the detection module.

[0006] In one embodiment of the present invention, the housing is provided with a sample inlet, multiple fluid inlets and a waste liquid outlet. The sample inlet is connected to a sample container storing liquid effluent and the resin column through a pipeline. The multiple fluid inlets are respectively connected to the liquid storage device and the multiple resin columns through pipelines. The waste liquid outlet is respectively connected to the multiple resin columns through pipelines. Waste liquid generated by the multiple resin columns is discharged from the waste liquid outlet.

[0007] In one embodiment of the present invention, the plurality of resin columns include a first cation resin column, an anion resin column, a second cation resin column, an iron adsorption resin column, a strontium adsorption resin column, a yttrium adsorption resin column, and a nickel adsorption resin column. The first cation resin column is connected to a sample container. The anion resin column is located downstream of and connected to the first cation resin column. The iron adsorption resin column, the strontium adsorption resin column, the yttrium adsorption resin column, and the nickel adsorption resin column are all located downstream of the anion resin column. The second cation resin column is located on the connecting branch between the iron adsorption resin column and the anion resin column. The strontium adsorption resin column is connected to the yttrium adsorption resin column. A temporary storage tank is provided between the yttrium adsorption resin column and the nickel adsorption resin column.

[0008] In one embodiment of the present invention, the plurality of separation liquid collection bottles include an iron separation liquid collection bottle, a strontium separation liquid collection bottle, a yttrium separation liquid collection bottle, and a nickel separation liquid collection bottle, which are respectively connected to the iron adsorption resin column, the strontium adsorption resin column, the yttrium adsorption resin column, and the nickel adsorption resin column via pipelines.

[0009] In one embodiment of the present invention, the control valve includes multiple multi-channel switching valves, multiple dual-flow switching valves, and a three-way valve. The multi-channel switching valves are disposed on the connecting pipeline between the liquid storage device and the resin column. One end of the dual-flow switching valve is connected to the multi-channel switching valve, and the other end is connected to the resin column. The three-way valve is disposed on the connecting pipeline between the resin column and the corresponding separation liquid collection bottle.

[0010] In one embodiment of the present invention, pressure sensors are provided at the inlet and outlet of the plurality of resin columns. The pressure sensors monitor the pressure changes in the pipeline in real time and feed back to the control unit to adjust the flow rate.

[0011] In one embodiment of the present invention, the detection module includes a four-channel β detector array with dual-mode detection, which is used to detect the radioactivity of Fe-55, Ni-63, Sr-89, and Sr-90, respectively.

[0012] In one embodiment of the present invention, the dual-mode detection includes a liquid scintillator detection unit and a Chernkov detection unit. The liquid scintillator detection unit uses a combination of a plastic scintillator and a photomultiplier tube to detect low-energy β rays of Fe-55 and Ni-63. The Chernkov detection unit uses a combination of a quartz window and a photomultiplier tube array to detect high-energy β rays of Sr-89 and Sr-90.

[0013] In one embodiment of the present invention, the control system includes an industrial computer and a PLC controller. The industrial computer has a built-in human-machine interface, and the PLC controller is electrically connected to the industrial computer, the cascaded separation module, the fluid control module, and the detection module.

[0014] In one embodiment of the present invention, the surface of the shell is provided with an acid and alkali resistant protective layer.

[0015] The beneficial effects of this invention are as follows: The online monitoring device for multiple nuclides in liquid effluents proposed in this invention integrates a cascaded separation module, a fluid control module, and a control system into a single device. Simultaneously, it constructs a cascaded separation module by constructing a multi-resin column array working in synergy. Combined with control valves and an injection pump, it achieves automatic switching of the multi-nucleus separation path, thereby enabling simultaneous monitoring of multiple nuclides, improving monitoring efficiency, and reducing monitoring costs. By compressing the traditional multi-system separation process into a single device, it significantly reduces the size of the nuclide monitoring equipment, saving space.

[0016] Furthermore, the cascade separation module employs graded enrichment and specific adsorption techniques, first using a cation exchange column to target Fe3+. + Ni 2 +、Sr2 + Primary enrichment was performed, followed by selective adsorption of FeCl4 using an anion exchange column. - Complexes, iron adsorption resin columns specifically adsorb Fe3+ + Nickel adsorption resin column specifically adsorbs Ni 2 Strontium adsorption resin columns and yttrium adsorption resin columns separate Sr isotopes, significantly improving the recovery rate of radionuclides. Dynamic flow path control technology, through a combination of multi-channel switching valves and dual-flow-path switching valves, enables automatic switching of multi-nuctopic diversion paths, thereby achieving synchronous monitoring of multiple nuclides and solving the problems of low efficiency and high cost in multi-nuctopic monitoring. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] In the attached diagram:

[0019] Figure 1 This is a schematic diagram of the structure of an online monitoring device for multiple nuclides in liquid effluent provided in an embodiment of the present invention;

[0020] Figure 2 This is a front view schematic diagram of an online monitoring device for multiple nuclides in liquid effluent provided in an embodiment of the present invention;

[0021] Figure 3 This is a partial structural diagram of the inner side of an online monitoring device for multiple nuclides in liquid effluent provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram showing the connection of the components of the online detection device for multiple nuclides in liquid effluent provided in one embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram showing the connection of each component in the cascade separation module of the online monitoring device for multiple nuclides in liquid effluent provided in one embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram showing the connection between the fluid control module and the cascade separation module of the online monitoring device for multiple nuclides in liquid effluent provided in one embodiment of the present invention.

[0025] The attached figures are labeled as follows:

[0026] 1000, Housing; 1100, Human-Machine Interface; 1200, Opening Door; 1210, Liquid Inlet; 1220, Switch Button; 100, Cascade Separation Module; 110, Resin Column Array; 111, First Cation Resin Column; 112, Anion Resin Column; 113, Second Cation Resin Column; 114, Iron Adsorption Resin Column; 115, Strontium Adsorption Resin Column; 116, Yttrium Adsorption Resin Column; 117, Nickel Adsorption Resin Column; 118, Temporary Storage Tank; 119, Waste Liquid Collection Tank ; 121. Iron separation liquid collection bottle; 122. Strontium separation liquid collection bottle; 123. Yttrium separation liquid collection bottle; 124. Nickel separation liquid collection bottle; 200. Fluid control module; 210. Control valve; 211. Multi-channel switching valve; 212. Dual-flow-path switching valve; 213. Three-way valve; 220. Feedback module; 221. Pressure sensor; 222. Thermometer; 223. pH meter; 230. Storage bottle; 240. Injection pump; 300. Detection module; 310. Beta detector. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0030] This invention provides an online monitoring device for multiple nuclides in liquid effluents. Through resin column array and flow path control technology, it can realize the synchronous processing and detection of multiple nuclides, shortening the single analysis time to less than 24 hours. At the same time, through automated fluid control, manual operation is reduced, which can reduce the radiation dose to personnel while eliminating human intervention.

[0031] Please see Figures 1 to 6 The online monitoring device for multiple nuclides in liquid effluent provided by this invention includes a housing 1000, a cascade separation module 100, a fluid control module 200, a detection module 300, and a control system. The housing 1000 has a receiving cavity, within which the cascade separation module 100, fluid control module 200, detection module 300, and control system are installed. The fluid control module 200 supplies pretreatment liquid, desorption liquid, and regeneration liquid to the cascade separation module 100, cooperating with the cascade separation module 100 to separate and purify radionuclides and regenerate resin. The detection module 300 detects the concentration of each nuclide in the separation liquid of the cascade separation module 100 and feeds the monitoring data back to the control system (not shown in the figure). The control system controls the operation of the cascade separation module 100, fluid control module 200, and detection module 300, and automatically plans the separation path according to measurement requirements, forming a closed-loop process of separation-detection-optimization.

[0032] Please see Figures 1 to 3The housing 1000 can be any structure with a receiving cavity, and its outer contour shape includes, but is not limited to, regular geometric shapes such as cuboids, cubes, and polygonal prisms, or irregular structures designed according to the requirements of the installation environment. In one embodiment, the outer contour of the housing 1000 is a cuboid structure, and its specific dimensions are not limited and can be set according to the actual installation environment requirements. In this embodiment, the housing 1000 is provided with a partition inside, which can divide the receiving cavity into vertically distributed upper and lower layer structures. The cascaded separation module 100 and the detection module 300 are located in the lower receiving cavity, and the fluid control module 200 and the control system are located in the upper receiving cavity. The fluid control module 200 is arranged along the side wall of the housing 1000, and the control system is located in the middle position of the upper receiving cavity, thereby making full use of the internal space of the housing 1000 and providing a compact and modular monitoring device, realizing the miniaturization and rapid maintenance of the device.

[0033] Please see Figure 4 and Figure 5 The cascade separation module 100 includes multiple resin columns for adsorbing nuclides and a separation liquid collection bottle connected to the multiple resin columns. The resin column array 110, composed of multiple resin columns, achieves the separation of multiple nuclides through the graded enrichment and specific adsorption of various nuclides in the liquid effluent. The type and number of resin columns are related to the types of nuclides to be separated. In one embodiment, the liquid effluent to be separated contains radioactive nuclides such as Fe, Ni, and Sr. The resin column array 110 then includes a first cation resin column 111, an anion resin column 112, a second cation resin column 113, an iron adsorption resin column 114, a strontium adsorption resin column 115, a yttrium adsorption resin column 116, a nickel adsorption resin column 117, a temporary storage tank 118, and a waste liquid collection tank 119. The first cation resin column 111 contains a large number of anion groups, such as sulfonic acid groups (-SO3). - ), carboxyl group (-COO) - The radionuclides in the liquid effluent exist as positively charged cations; therefore, the first cation exchange resin column 111 can initially enrich Fe. 3+ Ni 2 +、Sr2 + Metal ions, with a recovery rate >97%, were adsorbed by anion exchange resin column 112 for FeCl4. - Complex, secondary purification of Fe using a second cation exchange resin column 113 3+ Iron adsorption resin column 114 specifically adsorbs Fe 3+ For example, the TRU resin column achieved a recovery rate of 78.3%, and the nickel adsorption resin column 117 selectively adsorbed Ni. 2 +, with a recovery rate of 82.1%. Yttrium adsorption resin column 116 uses a DGA resin column. Since Sr-90 continuously decays to produce Y-90, the DGA resin column is used to adsorb Sr.2+ and Y 3+ The combination of strontium adsorption resin column 115 and DGA resin column can separate Sr isotopes (Sr-89 and Sr-90) with a recovery rate of 85.6% to 88.9%.

[0034] The first cation exchange resin column 111 is connected to a sample container (not shown in the figure) containing liquid effluent and a waste collection container 119 via pipelines. The liquid effluent flows from the sample container into the first cation exchange resin column 111, where Fe, Ni, Sr, and other ions are adsorbed onto the column via electrostatic adsorption or ion exchange reaction. The liquid effluent is then discharged into the waste collection container 119. An anion exchange resin column 112 is located downstream of and connected to the first cation exchange resin column 111. Iron adsorption resin columns 114, strontium adsorption resin columns 115, yttrium adsorption resin columns 116, and nickel adsorption resin columns 117 are arranged in parallel in the downstream branch of the anion exchange resin column 112. A second cation exchange resin column 113 is located in the connecting branch between the iron adsorption resin column 114 and the anion exchange resin column 112. The second cation exchange resin column 113 can further purify the iron ions in the desorbed liquid from the anion exchange resin column 112. The strontium adsorption resin column 115 and the yttrium adsorption resin column 116 are connected by a pipeline. A temporary storage tank 118 is located at the outlet of the yttrium adsorption resin column 116 and is connected to the nickel adsorption resin column 117 via a pipeline. Waste liquid collection tanks 119 are connected to each resin column. The number of separation liquid collection bottles is related to the number of nuclides to be separated. In this embodiment, the separation liquid collection bottles include an iron separation liquid collection bottle 121, a strontium separation liquid collection bottle 122, a yttrium separation liquid collection bottle 123, and a nickel separation liquid collection bottle 124. These bottles are connected to the iron adsorption resin column 114, the strontium adsorption resin column 115, the yttrium adsorption resin column 116, and the nickel adsorption resin column 117, respectively. In other embodiments, if it is necessary to monitor other nuclides, other resin columns can be replaced accordingly, for example, to monitor... 137 Cs was analyzed using an AMP (ammonium phosphomolybdate) resin column, with the eluent adjusted to 0.5 MH NO3; monitoring was performed. 60 Co, using TRP resin columns, adding DTPA complexing agents, etc. All of the above resin columns can be purchased through general commercial means.

[0035] Please see Figure 4The fluid control module 200 includes a liquid storage device, an injection pump 240, and a control valve 210. The liquid storage device includes multiple storage bottles 230 for storing nitric acid, hydrochloric acid, ammonium citrate, pH adjusting reagent, and scintillation solution. The nitric acid is available in two concentrations: 0.05-0.1M and 6-8M. The hydrochloric acid is available in two concentrations: 0.05M-0.1M and 4-6M. The ammonium citrate solution has a concentration of 1M-3M. Nitric acid can be used as a pretreatment solution to pretreat each resin column. The concentration of nitric acid used in resin column pretreatment depends on the type of resin column. For example, the pretreatment solution for a cation exchange resin column is 0.1M nitric acid, the pretreatment solution for a nickel adsorption resin column 117 is 1M ammonium citrate, and the pretreatment solution for anion exchange resin columns 112, iron adsorption resin columns 114, strontium adsorption resin columns 115, and yttrium adsorption resin columns 116 is 8M nitric acid. Hydrochloric acid can be used as an eluent; the choice depends on the type of resin column. Ammonia can be used as a pH adjusting agent. Nitric acid and hydrochloric acid of different concentrations should be stored in separate reservoirs. Figure 4 The storage bottles 230 are shown only as an example. The number of storage bottles 230 in the figure does not represent the actual number used in practice. The number of storage bottles 230 can be set according to actual needs. To facilitate the replacement of reagents in the storage bottles 230, each storage bottle 230 can be placed outside the housing 1000, ready to be used as needed. The number of syringe pumps 240 is consistent with the number of storage bottles 230. Under the control of the control system, multiple syringe pumps 240 deliver the solutions from multiple storage bottles 230 to the corresponding resin columns of the cascade separation module 100 according to instructions, so as to cooperate with the cascade separation module 100 to complete the separation and purification of radionuclides in the liquid effluent. In one embodiment, the syringe pump 240 is a vertical syringe pump, and the parameters of the syringe pump 240 are: flow rate 0.1-10 mL / min, back pressure 0.28 MPa, and PTFE piston.

[0036] Please see Figure 1 Furthermore, the side wall of the housing 1000 is provided with multiple liquid inlets 1210 and waste liquid outlets (not shown in the figure) communicating with the receiving cavity. The multiple liquid inlets 1210 include sample inlets and fluid inlets. The sample inlets are connected via pipelines to a sample container storing liquid effluent and a resin column. The multiple fluid inlets are respectively connected via pipelines to multiple storage bottles and multiple resin columns. The waste liquid outlets are respectively connected via pipelines to multiple resin columns, and the waste liquid generated by the multiple resin columns is discharged from the waste liquid outlets into a waste liquid collection tank 119. Even further, the housing 1000 is made of aluminum alloy, such as 6061 aluminum alloy, and the surface of the housing 1000 is provided with a protective layer, which is epoxy resin sprayed and can resist strong acid corrosion.

[0037] Please see Figure 4 and Figure 6The cascade separation module 100 utilizes control valves 210 to achieve multiple flow path combinations on its various pipelines. In one embodiment, the control valves 210 include multiple multi-channel switching valves 211, multiple dual-flow-path switching valves 212, and multiple three-way valves 213. The multiple multi-channel switching valves 211 are connected to each resin column and the storage bottle 230 of the cascade separation module 100 via pipelines, and the number of multi-channel switching valves 211 is consistent with the number of storage bottles 230. The multiple dual-flow-path switching valves 212 connect each resin column of the cascade separation module 100 to the multi-channel switching valves 211, and the number of dual-flow-path switching valves 212 is consistent with the number of resin columns. The three-way valves 213 are installed on the connecting pipeline between the resin column and the separated liquid collection bottle. Specifically, the multiple three-way valves 213 are installed on the drain pipelines of the iron adsorption resin column 114, the strontium adsorption resin column 115, the yttrium adsorption resin column 116, and the nickel adsorption resin column 117. One end of the three-way valve 213 is connected to the resin column, the other end is connected to the corresponding separation liquid collection bottle, and the remaining end is connected to the waste liquid collection tank 119. Since the pretreatment liquid and desorption liquid are highly acidic, all the above pipelines are made of acid-resistant polytetrafluoroethylene (PTFE). The multi-channel switching valve 211 is made of PCTFE, with a pressure resistance of 1.6 MPa and a response time of <0.5 s; the dual-flow switching valve 212 has a flow control accuracy of ±0.1 mL and an acid resistance rating of IP67.

[0038] Furthermore, the online monitoring device also includes a feedback module 220, which is used to monitor changes in pressure, temperature, and pH in the pipeline in real time and feed the data back to the control system. In one embodiment, the feedback module includes fourteen pressure sensors 221, eight thermometers 222, and nine pH meters 223. The fourteen pressure sensors 221 are respectively installed at the inlet and outlet ends of the seven resin columns of the cascade separation module 100, and are used to monitor pressure changes in the pipeline in real time and feed the data back to the control system to adjust the flow rate. The pressure sensors 221 have a range of 0-1.6 MPa and an accuracy of ±0.5% FS. One pH meter 223 is installed in the sample container, another pH meter 223 is installed in the temporary storage tank 118 at the inlet of the nickel adsorption resin column 117, and the remaining seven pH meters 223 are installed at the inlet ends of the seven resin columns of the cascade separation module 100, respectively. One thermometer 222 is installed in the temporary storage tank 118 at the inlet of the nickel adsorption resin column 117, and the seven thermometers 222 are installed at the outlet ends of the seven resin columns, respectively. The thermometers 222 have a range of 0-50℃ and an accuracy of ±0.5℃, and are used to monitor the operating temperature of the resin columns. The pressure sensor 221, thermometers 222, and pH meters can feed back real-time pressure, temperature, and pH data to the control system, enabling the control system to monitor the operating status in real time and provide timely feedback in case of abnormalities.

[0039] Please see Figure 2The detection module 300 includes multiple beta detectors 310, the number of which corresponds to the number of nuclides to be detected. In one embodiment, the detection module 300 includes a four-channel beta detector array with dual-mode detection, used to detect the radioactivity of Fe-55, Ni-63, Sr-89, and Sr-90, respectively. Specifically, the dual-mode detection includes a liquid scintillator detection unit and a Cherenkov detection unit. The liquid scintillator detection unit uses a combination of a plastic scintillator and a photomultiplier tube to detect low-energy beta rays of Fe-55 and Ni-63. The Cherenkov detection unit uses a combination of a quartz window and a photomultiplier tube array to detect high-energy beta rays of Sr-89 and Sr-90. Further, the plastic scintillator uses plastic scintillator microspheres (20 micrometers) made of polyethylene, coated with 1 wt% fluorescence enhancer PPO and 0.2 wt% wavelength transfer agent (POPOP); the photomultiplier tube uses Hamamatsu R6231-100 with a gain of 10. 6 The dark current is <1nA; the sample cell is made of quartz glass with a volume of 10mL and an acid resistance rating of IP68. This means that two of the four β detectors use liquid scintillation detection mode (β particle counting mode) to measure Fe-55 and Ni-63, and the other two use Cherenkov detection mode to measure Sr-89 and Sr-90. The detection module 300 transmits the measurement data to the control system, and simultaneously uploads the detection data to the data recording platform in real time, generating an encrypted and tamper-proof traceability record of the separation process.

[0040] Please see Figure 1 and Figure 4 The control system includes an industrial computer and a PLC controller. The PLC controller is electrically connected to the industrial computer and also electrically connected to the multi-channel switching valve 211, the dual-flow-path switching valve 212, and the syringe pump 230. The industrial computer has a built-in program and a human-machine interface 1100. The PLC controller controls the operation of the multi-channel switching valve 211, the dual-flow-path switching valve 212, and the syringe pump 230 through the built-in program. It can automatically plan the separation path according to measurement requirements and dynamically adjust the flow rate according to the feedback real-time parameters, forming a closed-loop process of separation-detection-optimization. The human-machine interface 1100 is located on the outer wall of the housing 1000. The feedback real-time parameters are displayed on the human-machine interface 1100, and operators can also perform various operations through the human-machine interface 1100. In this application, the control system processes various parameters and detection data through a built-in program to form a closed-loop process of separation-detection-optimization. The built-in program of the control system can adopt conventional programs in this field, which will not be described in detail here. To facilitate observation of the testing process, the lower layer of the housing 1000 is equipped with an opening and closing door 1200, which is made of a transparent material, such as transparent glass. The housing 1000 is also equipped with a switch button 1220 to control the entire device. When monitoring is required, the online monitoring device can be activated by using the switch button 1220.

[0041] The monitoring process using the online monitoring device of the present invention is as follows: The control system controls the storage device to deliver pretreatment liquid to the cascade separation module 100. First, the first cation resin column 111, the anion resin column 112, the second cation resin column 113, the iron adsorption resin column 114, the strontium adsorption resin column 115, the yttrium adsorption resin column 116, and the nickel adsorption resin column 117 are pretreated to reach the required pH. Then, the sample (liquid effluent) is injected into the first cation resin column 111. The cations (radioactive elements) in the sample are adsorbed on the first cation resin column 111, and the effluent is discharged to the waste liquid collection tank 119. The desorption process is then performed: the cation resin desorption solution is first injected into the first cation resin column 111 through the washing and storage device. The effluent passes sequentially through the anion resin column 112, the strontium adsorption resin column 115, and the yttrium adsorption resin column 116 and is then collected in the temporary storage tank 118. The pH value of the effluent in the temporary storage tank 118 is adjusted to 8-9 using ammonia water, and then injected into the nickel adsorption resin column 117. After being adsorbed by the nickel adsorption resin column 117, it is discharged into the waste liquid collection tank 119. Then, the desorption solution of the anion exchange resin column 112 is injected into the anion exchange resin column 112, and the effluent passes through the second cation exchange resin column 113 and is discharged into the waste liquid collection tank 119; the desorption solution of the cation exchange resin is then injected into the second cation exchange resin column 113, and the effluent passes through the iron adsorption resin column 114 and is discharged into the waste liquid collection tank 119; the desorption solutions of the iron adsorption resin, strontium adsorption resin, yttrium adsorption resin, and nickel adsorption resin are injected into the iron adsorption resin column 114, strontium adsorption resin column 115, yttrium adsorption resin column 116, and nickel adsorption resin column 117, respectively, to obtain separation solutions containing Fe, Ni, Sr, and Y, which are collected in the corresponding separation solution collection bottles. Finally, the regenerated solution is injected into the first cation resin column 111, the anion resin column 112, the second cation resin column 113, the iron adsorption resin column 114, the strontium adsorption resin column 115, the yttrium adsorption resin column 116, and the nickel adsorption resin column 117 respectively to achieve resin regeneration.

[0042] The Fe, Ni, Y, and S-containing separation liquid in the separation liquid collection bottle is injected into the detector of the detection module 300. After the measurement is completed by the β array detector, the result is output to the control system. After processing by the preset program, the raw data and the processing result are uploaded to the data recording platform.

[0043] In one embodiment, the control system can automatically plan the separation path according to the monitoring requirements of the sample. If the sample only needs to measure Fe nuclides, the desorption solution of the anion exchange resin column 112 does not pass through the strontium adsorption resin column 115, the yttrium adsorption resin column 116 and the nickel adsorption resin column 117.

[0044] The processing procedure of the online monitoring device will be described in detail below through a specific embodiment.

[0045] Resin column pretreatment:

[0046] First, the pretreatment solution in the storage device is injected into each resin column using the syringe pump 240 to pretreat the resin columns to achieve the required pH. For example, the first cation exchange resin column 111 and the second cation exchange resin column 113 use 0.1M HNO3, 20 mL, at a flow rate of 4 mL / min; the nickel adsorption resin column 117 uses 1M ammonium citrate, 20 mL, at a flow rate of 4 mL / min; the anion exchange resin column 112, the iron adsorption resin column 114, the strontium adsorption resin column 115, and the yttrium adsorption resin column 116 use 8M HNO3, 20 mL, at a flow rate of 4 mL / min.

[0047] Sample loading:

[0048] After the liquid effluent is adjusted to a pH of 2.0 ± 0.1 by an online pH meter, it is pumped into the first cation exchange resin column 111 at a rate of 4 mL / min by a syringe pump.

[0049] Nuclide separation process:

[0050] Fe-55 separation:

[0051] (1) Use a syringe pump to draw 30 mL of 8 M HNO3 to rinse the first cation exchange resin column 111, Fe3+. + FeCl4 - The eluent enters the anion exchange resin column 112, and after passing through the strontium adsorption resin column and the yttrium adsorption resin column, it is collected and the pH is adjusted to 8-9 with ammonia.

[0052] (2) Use a syringe pump to draw 4-6M HCl (40mL) to wash the anion exchange resin column 112 and remove impurity ions;

[0053] (3) Use a syringe pump to draw 0.05-0.1M HCl (30mL) to elute Fe3+. + To the second cation exchange resin column 113;

[0054] (4) Use a syringe pump to draw 6-8M HNO3 (30mL) to elute Fe3+. + To the iron adsorption resin column 114;

[0055] (5) Use a syringe pump to draw 0.5M-1M HPO4 (10mL) to elute Fe from the iron adsorption resin column 114. 3+ To the iron separation liquid collection bottle 121.

[0056] Ni-63 separation:

[0057] (1) The eluent (pH 8.5, 20 mL) after pH adjustment with ammonia water in the above steps was drawn by a syringe pump and passed through a nickel adsorption resin column 117. 2+Enter the nickel column;

[0058] (2) Use a syringe pump to draw 3M HCl (10mL) to elute Ni from the nickel adsorption resin column 117. 2 +To nickel separation solution collection bottle 122.

[0059] Sr isotope separation:

[0060] (1) Use a syringe pump to draw 0.1M HNO3 (10mL) to elute 89Sr from the strontium adsorption resin column 115 to the strontium separation collection bottle 123.

[0061] (2) Use a syringe pump to draw 0.1M HCl (10mL) to elute 90Sr (Y90) in the yttrium adsorption resin column 116 and transfer it to the yttrium separation liquid collection bottle 124.

[0062] During the above process, the multi-channel switching valve 211, the dual-flow-path switching valve 212, and the three-way valve 213 are freely combined under the control of the PLC controller to complete the entire process of pretreatment, sample loading, rinsing, and desorption. At the same time, the data from the pressure sensor 221 is fed back to the PLC controller in real time, and the PLC controller dynamically adjusts the flow rate of the syringe pump 240 according to the changes in the pipeline pressure value.

[0063] After desorption by each resin column in the cascade separation module 100, the resulting separation solutions containing radionuclides are collected in iron separation solution collection bottles 121, nickel separation solution collection bottles 122, strontium separation solution collection bottles 123, and yttrium separation solution collection bottles 124. These solutions are then detected by the detection module 300, specifically as follows: the iron and nickel separation solutions are detected using the β counting detection unit of the β detector 310, with a magnification of 1000x and an energy threshold <100keV. The strontium and yttrium separation solutions are detected using the Cherenkov detection unit of the β detector 310, with an energy threshold >500keV and an integration time of 300 minutes. After detection, the data is fed back to the control system.

[0064] The test results data of the online monitoring device of this application are as follows:

[0065] (1) Chemical recovery rate

[0066]

[0067]

[0068] (2) Limit of Detection (LLD) for TER waste liquid

[0069]

[0070] The online monitoring device of this application can be used for monitoring TER waste liquid in nuclear power plants, such as TER waste liquid from a CPR1000 unit, with a daily discharge of 1 tank of liquid effluent, volume 3L, monitoring Sr-90, Fe-55, and Ni-63.

[0071] The operating procedure is as follows: The device automatically completes sample loading, radionuclide separation and detection, and the analysis time for a single 3L sample is less than 24 hours (the traditional method requires 72 hours).

[0072] The output report shows: Fe-55 activity 12.3±1.2 Bq / L, Ni-63 activity 8.7±0.9 Bq / L, Sr-90 activity 0.35±0.05 Bq / L (complies with the requirements of the National Nuclear Safety Administration Document

[2020] No. 44).

[0073] Benefit analysis: Reduced labor costs: Saves 1,200 hours of monitoring personnel annually.

[0074] The online monitoring device of this application can also be used for emergency monitoring of SEL discharge liquid. For example, if the radioactivity level of SEL discharge liquid in a power plant increases due to system abnormality, it is necessary to urgently monitor Sr-89 / Sr-90.

[0075] Operating Procedure: The device is activated in rapid mode (shortening rinsing time), prioritizing Sr isotope separation. Results are output within 6 hours: Sr-89 activity 1.2±0.2 Bq / L, Sr-90 activity 0.8±0.1 Bq / L. At this point, an alarm is triggered and the discharge valve is automatically closed to prevent over-discharge.

[0076] This application also conducted lifespan and replacement tests on the resin column in the online monitoring device. For the Dowex 50WX8 model cation exchange resin column: after 10 consecutive uses, Fe... 3+ Recovery rate drops below 90%; NiResin nickel resin column: after 15 consecutive uses, Ni 2+ The recovery rate dropped to below 75%.

[0077] When replacing the resin column: close the corresponding flow path valve; remove the quick-release clamp connector and take out the old resin column; install the new resin column and start the activation program, which takes 5 minutes.

[0078] In summary, this application constructs a seven-column synergistic resin column array to achieve simultaneous processing of Fe-55, Ni-63, and Sr-89 / 90: ① Hierarchical enrichment and specific adsorption technology: Fe3+ is processed using a Dowex 50WX8 cation exchange column. + Ni 2 +、Sr2 + Primary enrichment was performed (recovery > 97%), followed by selective adsorption of FeCl4- complexes (detergent agent > 10) using an AG1-X8 anion exchange column.3 TRU resin column specifically adsorbs Fe3+ + (Recovery rate 78.3%), nickel resin column specifically adsorbs Ni 2 + (Recovery rate 82.1%), Sr isotope separation using strontium resin column and DGA resin column (recovery rate 85.6%-88.9%); ② Dynamic flow path control technology: Through hundreds of combination modes of multi-channel switching valves and dual-flow path switching valves, automatic switching of multi-nucleus diversion paths is achieved, compressing the traditional multi-system separation process into a single device. This architecture reduces the single analysis time from 72 hours to 24 hours, reduces the equipment size by 80%, and solves the problems of low efficiency and high cost of multi-nucleus monitoring in nuclear power plants.

[0079] This application adopts a vertical layout: a stacked design of the lower resin column and detection module, and the upper valve array, pump body, and control system, compressing the device size to 700×500×650mm; ② Quick-release maintenance structure: the resin column uses 1 / 4-inch clamp connectors (PTFE sealing rings), which can be replaced within 5 minutes, improving maintenance efficiency by 5 times; Corrosion-resistant integrated shell: 6061 aluminum alloy + epoxy resin spraying (resistant to 8MHNO3 corrosion), with a lifespan of >10 years. This design allows the device to be directly installed on the nuclear power plant's discharge pipeline, achieving in-situ online monitoring and replacing traditional methods.

[0080] The online monitoring device for multiple nuclides in liquid effluents provided by this invention integrates a cascaded separation module, a fluid control module, and a control system into a single device. It also constructs a cascaded separation module by constructing a multi-resin column array, combining a control valve and an injection pump to achieve automatic switching of the multi-nucleus separation path, thereby enabling simultaneous monitoring of multiple nuclides, improving monitoring efficiency, and reducing monitoring costs. By compressing the traditional multi-system separation process into a single device, the size of the nuclide monitoring equipment is significantly reduced, saving space and solving the problems of scattered redundancy and low automation in sample processing and monitoring equipment.

[0081] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A multi-nucleoside online monitoring device for liquid effluent, characterized in that, include: case; A cascade separation module is disposed within the housing, the cascade separation module comprising multiple resin columns for adsorbing nuclides and a separation liquid collection bottle communicating with the multiple resin columns. The fluid control module includes a liquid storage device, an injection pump, and a control valve. The liquid storage device is connected to multiple resin columns via pipelines. The injection pump and the control valve are respectively installed on the pipelines to control the flow direction and flow rate of the fluid in the liquid storage device. A detection module, disposed within the housing, is used to detect the radioactivity of the nuclide; A control system is disposed within the housing, and the control system is used to control the operation of the cascaded separation module, the fluid control module, and the detection module.

2. The online monitoring device for multiple nuclides in liquid effluent according to claim 1, characterized in that, The housing is provided with a sample inlet, multiple fluid inlets, and a waste liquid outlet. The sample inlet is connected to a sample container containing liquid effluent and the resin column via a pipeline. The multiple fluid inlets are respectively connected to the liquid storage device and the multiple resin columns via pipelines. The waste liquid outlet is respectively connected to the multiple resin columns via pipelines. Waste liquid generated by the multiple resin columns is discharged from the waste liquid outlet.

3. The online monitoring device for multiple nuclides in liquid effluent according to claim 1, characterized in that, The plurality of resin columns include a first cation resin column, an anion resin column, a second cation resin column, an iron adsorption resin column, a strontium adsorption resin column, a yttrium adsorption resin column, and a nickel adsorption resin column. The first cation resin column is connected to the sample container. The anion resin column is located downstream of and connected to the first cation resin column. The iron adsorption resin column, the strontium adsorption resin column, the yttrium adsorption resin column, and the nickel adsorption resin column are all located downstream of the anion resin column. The second cation resin column is located on the connecting branch between the iron adsorption resin column and the anion resin column. The strontium adsorption resin column is connected to the yttrium adsorption resin column. A temporary storage tank is provided between the yttrium adsorption resin column and the nickel adsorption resin column.

4. The online monitoring device for multiple nuclides in liquid effluent according to claim 3, characterized in that, The plurality of separation liquid collection bottles include iron separation liquid collection bottles, strontium separation liquid collection bottles, yttrium separation liquid collection bottles and nickel separation liquid collection bottles, which are respectively connected to the iron adsorption resin column, the strontium adsorption resin column, the yttrium adsorption resin column and the nickel adsorption resin column through pipelines.

5. The online monitoring device for multiple nuclides in liquid effluent according to claim 4, characterized in that, The control valve includes multiple multi-channel switching valves, multiple dual-flow switching valves, and a three-way valve. The multi-channel switching valve is installed on the connecting pipeline between the liquid storage device and the resin column. One end of the dual-flow switching valve is connected to the multi-channel switching valve, and the other end is connected to the resin column. The three-way valve is installed on the connecting pipeline between the resin column and the corresponding separation liquid collection bottle.

6. The online monitoring device for multiple nuclides in liquid effluent according to claim 1, characterized in that, Pressure sensors are installed at the inlet and outlet of each of the resin columns. The pressure sensors monitor the pressure changes in the pipeline in real time and feed them back to the control unit to adjust the flow rate.

7. The online monitoring device for multiple nuclides in liquid effluent according to claim 1, characterized in that, The detection module includes a four-channel β detector array with dual-mode detection, used to detect the radioactivity of Fe-55, Ni-63, Sr-89, and Sr-90, respectively.

8. The online monitoring device for multiple nuclides in liquid effluent according to claim 7, characterized in that, The dual-mode detection includes a liquid scintillator detection unit and a Chernkov detection unit. The liquid scintillator detection unit uses a combination of a plastic scintillator and a photomultiplier tube to detect low-energy β rays of Fe-55 and Ni-63. The Chernkov detection unit uses a combination of a quartz window and a photomultiplier tube array to detect high-energy β rays of Sr-89 and Sr-90.

9. The online monitoring device for multiple nuclides in liquid effluent according to claim 1, characterized in that, The control system includes an industrial computer and a PLC controller. The industrial computer has a built-in human-machine interface, and the PLC controller is electrically connected to the industrial computer, the cascaded separation module, the fluid control module, and the detection module.

10. The online monitoring device for multiple nuclides in liquid effluent according to claim 1, characterized in that, The surface of the shell is provided with an acid and alkali resistant protective layer.

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