A system and method for on-line boron concentration detection in a nuclear power plant

Abstract

This invention discloses an online boron concentration detection system and method for nuclear power plants. The system includes: a sample introduction module for pretreating a boron-containing aqueous sample to obtain a sample aerosol, and delivering the sample aerosol to the reaction end; a microwave plasma torch generation module for receiving the sample aerosol delivered by the sample introduction module and forming a high-temperature microwave plasma torch through microwave field coupling, then generating a characteristic spectrum through the high-temperature microwave plasma torch; and a characteristic spectrum identification and concentration detection module for acquiring the characteristic spectrum and performing qualitative identification and quantitative calculation to obtain the corresponding boron element concentration data. This invention, by employing microwave-induced plasma spectroscopy technology, enables accurate online analysis of boron concentration in liquid samples, thereby improving the detection accuracy and efficiency of boron.

Description

Technical Field

[0001] This invention relates to the field of element detection technology, and in particular to an online boron concentration detection system and method for nuclear power plants. Background Technology

[0002] In the operation of pressurized water reactor nuclear power plants, boric acid (H3BO3) is a crucial chemical compensation control agent and nuclear safety protection medium. Its boron-10 isotope has a high thermal neutron absorption cross-section, which can efficiently capture core fission neutrons, thereby achieving three core functions: precise control of reactor reactivity, emergency mitigation of accident conditions, and auxiliary protection of the loop system. It is a key chemical substance for ensuring the safe, stable, and economical operation of nuclear power plants. Accurate measurement of boron concentration is a prerequisite for achieving reactor reactivity control and nuclear safety protection; concentration deviations directly endanger reactor operational safety. Therefore, the reliability and accuracy of boron concentration monitoring technology are of paramount importance.

[0003] During normal operation of a pressurized water reactor (PWR), operators precisely control the reactor fission reaction rate by adjusting the concentration of boric acid in the primary coolant, thus compensating for reactivity gaps not covered by control rods. Real-time monitoring of boron concentration is also a core element in achieving closed-loop temperature control and stable power output, effectively preventing the risk of reactivity runaway. In accident scenarios, boric acid becomes a critical barrier for emergency reactor shutdown and core destruction, playing a vital role in defense-in-depth. Rapid and accurate boron concentration detection is crucial for ensuring the effectiveness of boron injection during an accident, promptly terminating the chain reaction, preventing safety barrier failure, and avoiding the escalation of the accident.

[0004] In addition to boron concentration monitoring, monitoring of key nuclides in the primary loop is also one of the key directions for subsequent primary loop water quality control in nuclear power plants. Among them, lithium and zinc are key metals in primary loop water chemistry, and their concentration changes directly affect the stability and safety of nuclear power plant operation and maintenance. Therefore, it is even more necessary to achieve efficient online monitoring of lithium and zinc ions to further improve the primary loop water quality control system.

[0005] Currently, the traditional method for monitoring boron concentration in nuclear power plants is a neutron source boron meter. This technology is based on the selective capture and absorption principle of thermal neutrons by the boron-10 isotope to achieve quantitative detection of boron concentration. Its core measurement process mainly consists of four steps: First, a thermal neutron beam is continuously emitted using isotopic neutron sources such as Am-Be and Pu-Be to form a stable neutron field; second, the boric acid solution to be tested flows through the measurement cell, where boron atoms in the solution capture a large number of thermal neutrons, and the higher the boron concentration, the more neutrons are absorbed; subsequently, the unabsorbed transmitted neutrons enter detectors such as the fission ionization chamber and the BF3 proportional counter, generating an ionization current signal through nuclear reactions; finally, since the detected neutron count rate is negatively correlated with the boron concentration, the system converts the neutron count signal into a boric acid concentration value through a calibration curve, completing the quantitative detection.

[0006] While neutron source boron meters have certain application value in some special scenarios, this technology, which relies on the neutron capture principle to monitor boron content, has multiple inherent drawbacks, including radiation safety, measurement stability, operation and maintenance costs, and scenario adaptability. Specifically, these drawbacks include: Neutron source boron meters use radioactive isotope neutron sources such as Am-Be and Cf-252, inherently posing radiation safety risks, and requiring extremely stringent compliance management throughout their entire lifecycle. Firstly, the radiation safety risks are significant, with risks of radioactive leakage and external radiation exposure during daily use, storage, and transportation. Dedicated shielding facilities and comprehensive emergency response plans are essential, and operators must be certified and receive regular radiation protection training, placing immense pressure on daily management. Secondly, for monitoring lithium and zinc ions, operators must collect samples on-site and then return to the laboratory for concentration measurement using an expensive mass spectrometer, a cumbersome and inefficient process. On the other hand, the compliance approval process is cumbersome. The application of this technology requires multiple administrative approvals, including radiation safety permits, source term registration, and environmental protection acceptance. When the equipment is decommissioned, qualified professional institutions must be entrusted to dispose of the waste source. The overall process is complex and time-consuming, making it difficult for ordinary laboratories or industrial sites to quickly deploy and implement it. In addition, source term decay is irreversible. The intensity of the neutron source will continue to decrease with the half-life. Not only does it require regular calibration to compensate for signal drift, but the source term must also be replaced after reaching its service life. The waste source disposal cost is high, and it faces significant environmental control pressure, further limiting the promotion and application of this technology. Summary of the Invention

[0007] This invention provides an online boron concentration detection system and method for nuclear power plants, aiming to improve the accuracy and efficiency of boron concentration detection.

[0008] This invention provides an online boron concentration detection system for nuclear power plants, comprising: The sample introduction module is used to pretreat the test liquid sample containing boron water sample to obtain sample aerosol, and to transport the sample aerosol to the reaction end; The microwave plasma torch generating module is used to receive the sample aerosol delivered by the sample introduction module, and to form a high-temperature microwave plasma torch on the sample aerosol through microwave field coupling, and then to generate characteristic spectra through the high-temperature microwave plasma torch. The feature spectrum identification and concentration detection module is used to collect the feature spectrum and perform qualitative identification and quantitative calculation on the feature spectrum to obtain the corresponding boron element concentration data.

[0009] Furthermore, it also includes: An online verification module is used to monitor and verify the overall boron concentration detection process; wherein, the monitoring and verification methods include inserting standard substances, blank controls, and signal drift correction.

[0010] Furthermore, it also includes: An online self-cleaning module is used to clean crystallized and deposited impurities in the sample introduction module and the microwave plasma torch generation module; wherein the cleaning process includes online acid washing, plasma burn-off, and pipeline purging.

[0011] Furthermore, the microwave plasma torch generating module and the characteristic spectrum recognition and concentration detection module operate in parallel.

[0012] Furthermore, the sample introduction module includes: The sample preparation and pretreatment unit is used to introduce a test liquid sample containing boric acid solution through a pipeline and to pretreat the test liquid sample; wherein, the pretreatment includes quantitative injection, filtration to remove impurities and acidity adjustment; The boric acid sample atomization unit is used to convert pretreated liquid samples into sample aerosols by means of one or more of a peristaltic pump, an atomizer, and / or atomizing chamber, according to flow control requirements.

[0013] Furthermore, the microwave plasma torch generating module includes: The microwave generator unit is used to generate high-frequency microwave energy to provide an energy source for plasma formation. A gas control unit is used to control the flow rates of the working gas and the carrier gas to transport the sample aerosol; wherein the working gas includes any one or more of argon, nitrogen, and air; The plasma torch unit is used to form high-temperature microwave plasma on the sample aerosol, and to induce energy level transitions of element atoms or ions and emit characteristic spectra through the high-temperature microwave plasma.

[0014] Furthermore, the feature spectrum recognition and concentration detection module includes: Background acquisition unit, used to pre-acquire the background spectrum of the plasma; A sample spectral acquisition unit is used to acquire the characteristic spectrum through a filtering method; The data processing unit is used to combine the background spectrum and the characteristic spectrum, convert them into an analog quantity of boron concentration through linear transformation, and set the analog quantity as the boron concentration data.

[0015] Furthermore, the data processing unit includes: An isotope processing unit is used to obtain the average wavelength of boron isotopes and perform analog quantity conversion based on the average wavelength; wherein the boron isotopes include 10 B and 11 B; And used in isotopes 10 When the abundance of B decreases to a preset abundance threshold, it is detected by isotope analysis. 10 B and 11 The characteristic spectral line differences of B correct the analog quantity.

[0016] This invention also provides a method for detecting online boron concentration in a nuclear power plant, applicable to the detection of online boron concentration in a nuclear power plant as described in any of the preceding embodiments, the method comprising: The test liquid sample containing boron water is pretreated to obtain a sample aerosol, and the sample aerosol is then transported to the reaction end. A high-temperature microwave plasma torch is formed on the sample aerosol through microwave field coupling, and then the high-temperature microwave plasma torch is used to excite and generate characteristic spectra. The characteristic spectra are qualitatively identified and quantitatively calculated to obtain the corresponding boron concentration data.

[0017] Furthermore, the step of forming a high-temperature microwave plasma torch on the sample aerosol through microwave field coupling, and then generating a characteristic spectrum by excitation through the high-temperature microwave plasma torch, includes: High-frequency microwave energy is generated by a microwave generator unit to provide an energy source for plasma formation. The sample aerosol is transported by controlling the flow rates of the working gas and the carrier gas; wherein the working gas includes any one or more of argon, nitrogen, and air; High-temperature microwave plasma is formed on the sample aerosol by a plasma torch, and the high-temperature microwave plasma causes element atoms or ions to undergo energy level transitions and emit characteristic spectra.

[0018] Furthermore, the qualitative identification and quantitative calculation of the characteristic spectrum to obtain the corresponding boron concentration data includes: Pre-collection of the plasma background spectrum; The characteristic spectrum is acquired using a filtering method; By combining the background spectrum and the characteristic spectrum, a simulated value of boron concentration is calculated through linear transformation, and this simulated value is set as the boron concentration data.

[0019] This invention provides an online boron concentration detection system and method for nuclear power plants. By employing microwave-induced plasma (MIP) spectroscopy, it achieves accurate online analysis of boron concentration in liquid samples. This method abandons the neutron capture principle relied upon by traditional neutron source boron meters, eliminating the inherent radiation safety hazards and stringent compliance controls of radioactive isotope neutron sources throughout their entire lifecycle. This fundamentally avoids the safety risks and regulatory pressures associated with neutron sources. Compared to traditional technologies, this detection system not only offers higher measurement accuracy but also features real-time self-checking capabilities, ensuring the reliability of the detection data throughout the process. Furthermore, it eliminates the need for on-site sampling by operators, effectively avoiding radioactive safety risks during sampling and significantly improving the accuracy and efficiency of boron concentration detection. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the principle architecture of an online boron concentration detection system for a nuclear power plant provided in an embodiment of the present invention; Figure 2 This is a schematic flowchart of an online boron concentration detection method for nuclear power plants, provided as an embodiment of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0024] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0026] Please see below. Figure 1 The present invention provides an online boron concentration detection system for nuclear power plants, comprising: The sample introduction module 100 is used to pretreat the test liquid sample containing boron water sample to obtain sample aerosol, and to transport the sample aerosol to the reaction end. The microwave plasma torch generating module 200 is used to receive the sample aerosol delivered by the sample introduction module 100, and to form a high-temperature microwave plasma torch on the sample aerosol through microwave field coupling, and then generate a characteristic spectrum through the high-temperature microwave plasma torch. The feature spectrum identification and concentration detection module 300 is used to acquire the feature spectrum and perform qualitative identification and quantitative calculation on the feature spectrum to obtain the corresponding boron element concentration data.

[0027] In this embodiment, the detection system specifically includes a sample introduction module 100, a microwave plasma torch generation module 200, and a characteristic spectrum recognition and concentration detection module 300. The sample introduction module 100 is the entry point and foundation of the entire analytical process. Its core function is to accurately, stably, and continuously deliver boron-containing aqueous samples (to be tested) to the reaction end, while simultaneously performing pretreatment such as quantitative injection, filtration to remove impurities, and acidity control, providing a uniform and stable sample aerosol for the subsequent plasma excitation stage. The operational stability of this module directly determines the consistency of the subsequent detection signal. Fluctuations in sample introduction, pipeline blockage, or sample residue will directly cause spectral signal drift; therefore, it is a prerequisite for the efficient operation of the other modules.

[0028] The microwave plasma torch generation module 200 is the energy core and excitation center of the MIP analysis technology. It directly receives the sample aerosol delivered by the sample introduction module 100 and forms a high-temperature microwave plasma torch through microwave field coupling. This provides sufficient atomization and excitation energy for the trace elements to be measured, causing energy level transitions in element atoms / ions and emitting characteristic spectra. As a key bridge connecting sample introduction and spectral detection, its plasma stability and excitation efficiency directly determine the intensity and quality of the spectral signal. At the same time, it relies on the online self-cleaning module 500 to remove interference such as boron crystals and matrix deposition to maintain the stable excitation state of the plasma torch.

[0029] The characteristic spectral identification and concentration detection module 300 is the signal terminal and quantitative core of the entire analysis system. It is responsible for acquiring the characteristic spectral signals generated by microwave plasma excitation. Through spectral analysis, target spectral line identification, noise removal, and signal integration, it completes the qualitative identification and quantitative calculation of trace multi-element data, and finally outputs elemental concentration data. This module directly receives the spectral signal excited by plasma and is the final output port of the detection results. Its detection accuracy is highly dependent on the stability of plasma excitation and the uniformity of sample injection; and it needs to be calibrated by the online calibration module 400 to ensure the reliability of the quantitative results.

[0030] This embodiment utilizes microwave-induced plasma (MIP) spectroscopy to achieve precise online analysis of boron concentration in liquid samples. This method abandons the neutron capture principle relied upon by traditional neutron source boron meters, eliminating the inherent radiation safety hazards and stringent compliance controls of radioactive isotope neutron sources throughout their entire lifecycle. This fundamentally avoids the safety risks and regulatory pressures associated with neutron sources. Compared to traditional technologies, this detection system not only offers higher measurement accuracy but also features real-time self-checking capabilities, ensuring the reliability of the detection data throughout the process. Furthermore, it eliminates the need for on-site sampling by operators, effectively avoiding radioactive safety risks during sampling and significantly improving the accuracy and efficiency of boron concentration detection.

[0031] Furthermore, the detection system provided in this embodiment has strong adaptability and can be directly introduced into existing nuclear sampling systems for in-situ replacement without requiring large-scale reconstruction of the existing system. This significantly reduces the difficulty of modification, construction period, and investment costs, and facilitates easy integration with the existing operation and maintenance system of nuclear power plants. The detection system also boasts advantages of safety, reliability, and ease of operation and maintenance. It completely eliminates the inherent radiation safety hazards and stringent compliance controls of radioactive isotope neutron sources throughout their entire lifecycle. This fundamentally eliminates various safety risks and compliance control pressures during the use, storage, transportation, and disposal of neutron sources. Simultaneously, it avoids the inherent defect of neutron sources requiring periodic calibration and drift compensation due to the continuous decay of intensity over half-life, effectively reducing operation and maintenance workload and costs, and improving system operational stability. Furthermore, compared to traditional technologies that can only detect boron concentration, this system can simultaneously and accurately measure multiple elements (such as lithium, zinc, and other key metal elements in primary loop water chemistry) in addition to boric acid. It does not require additional specialized testing equipment or on-site sampling by operators for offline laboratory testing. This further improves the primary loop water quality control system of nuclear power plants, enhances the stability, safety, and testing efficiency of nuclear power plant operation and maintenance, and provides more comprehensive technical support for the safe, stable, and economical operation of nuclear power plants.

[0032] In one embodiment, the online boron concentration detection system for the nuclear power plant further includes: The online verification module 400 is used to monitor and verify the overall detection process of boron concentration; wherein, the monitoring and verification methods include inserting standard substances, blank control, and signal drift correction.

[0033] The online calibration module 400 described in this embodiment is the core of the end-to-end quality control to ensure detection accuracy. It runs through the entire process of sample introduction, excitation, and detection. Its core function is to dynamically monitor sample introduction accuracy, plasma stability, and spectral detection deviation through real-time insertion of standard substances, blank controls, and signal drift correction. It promptly corrects systematic errors caused by matrix interference, instrument drift, and residual contamination, providing accurate calibration basis for the characteristic spectrum identification and concentration detection module 300. Although this module does not directly participate in sample excitation and spectral acquisition, it links with other modules throughout the process to achieve real-time dynamic quality control, thus solidifying the baseline of data accuracy for trace multi-element detection.

[0034] To ensure the effectiveness of the calibration, a calibration standard solution must be prepared in advance, i.e., a standard boric acid solution must be prepared, and this solution must cover the concentration of at least two points within the measurement range. In practical applications, a reasonable calibration cycle can be determined based on the stability and operating requirements of the instrument. The calibration standard solution is introduced into the detection system periodically via automatic valve switching according to the cycle, and the sample testing procedure is strictly followed. Finally, by testing the concentration of the calibration standard solution, the deviation generated by the system measurement is corrected to the standard value, ensuring that the accuracy of the entire detection system is always within the qualified range.

[0035] In another embodiment, the online boron concentration detection system for the nuclear power plant further includes: The online self-cleaning module 500 is used to clean the crystallized and deposited impurities in the sample introduction module 100 and the microwave plasma torch generation module 200; wherein the cleaning method includes online acid washing, plasma burn-off and pipeline purging.

[0036] The online self-cleaning module 500 described in this embodiment is the core of the instrument's operation and maintenance guarantee and interference prevention for long-term stable operation. Its design is based on the inherent characteristics of microwave-induced plasma (MIP) atomic spectroscopy detection and the special operating conditions of primary loop water samples from nuclear power plants: the MIP plasma temperature is lower than ICP, making it more prone to residue and salt formation in the primary loop boric acid solution. Furthermore, the primary loop contains a small amount of radioactivity, requiring regular cleaning to reduce the impact of residue on measurement accuracy. Specifically, the interference and residue problems that easily occur during detection mainly include: salt and scale formation on the inner wall of the plasma tube / microwave cavity; adsorption of metal ions in the atomization chamber and sample introduction pipeline; deposition of high-salt, high-boron, high-phosphorus, and high-silicon samples due to their difficulty in volatilization; and memory effects (with the memory effects of B, Hg, Pb, As, and Zn elements being the most pronounced).

[0037] To address the issues of boron salt deposition, boric acid crystallization, matrix residue, and memory effect that easily occur in boron-containing water samples during MIP atomic spectroscopy detection, the online self-cleaning module 500 in this embodiment establishes a graded cleaning and interference control system to effectively ensure the accuracy and stability of the detection results. Firstly, pretreatment is performed before sample detection: the boron-containing water sample is filtered through an aqueous filter membrane and diluted ≥5 times with a 5% dilute nitric acid system, strictly controlling the sample acidity within the range of 2%~5%, thus preventing boric acid crystallization induced by insufficient acidity at the source, and reducing the risk of adsorption and deposition of high-concentration boric acid and salts in the sample introduction system. Secondly, a periodic automatic cleaning procedure is executed during the detection process: after each certain amount or time of detection, an online cleaning process is automatically inserted, sequentially injecting 5% nitric acid solution to flush the pipeline and atomization chamber, promptly dissolving trace amounts of boron crystals in the pipeline; subsequently, the MIP plasma is ignited and purged for 3 minutes, followed by rinsing the system with ultrapure water for 8~10 minutes; after rinsing, the flame is extinguished, and the blank signal baseline is checked to confirm the absence of residue and crystal interference before continuing sample introduction and detection. In addition, all samples after testing and liquids generated during the purification and rinsing process are condensed, collected, and discharged in a standardized manner through dedicated pipelines to ensure that the entire testing and purification process complies with environmental protection and nuclear safety control requirements.

[0038] The online self-cleaning module 500 uses automated cleaning methods such as online acid washing, plasma dry burning, and pipeline purging to remove crystallized and deposited impurities from the inner walls of the sample introduction module 100 and the microwave plasma torch generation module 200 in real time. This effectively avoids problems such as pipeline blockage, signal drift, and cross-contamination, clearing operational obstacles for the aforementioned modules and continuously ensuring sample introduction smoothness, plasma stability, and detection optical path cleanliness. It is the key to achieving continuous online analysis, and is especially suitable for the long-term detection needs of samples with easy crystallization and high residue characteristics, such as boron-containing water samples.

[0039] Therefore, the detection system provided in this embodiment comprises five core modules: a sample introduction module 100, a microwave plasma torch generation module 200, a characteristic spectrum identification and concentration detection module 300, an online calibration module 400, and an online self-cleaning module 500. These modules work in an orderly and interconnected manner, supporting each other to construct a closed-loop analysis system covering the entire process of "sample delivery—plasma excitation—spectral detection—quality calibration—residue purification." In practical applications, each module has a clear division of labor and operates collaboratively, jointly ensuring the stability of online detection, data accuracy, and reliability of long-term continuous operation.

[0040] In one embodiment, the microwave plasma torch generating module 200 and the characteristic spectrum recognition and concentration detection module 300 operate in parallel.

[0041] This embodiment addresses the need for continuous measurement by designing the microwave plasma torch generation module 200 and the characteristic spectrum recognition and concentration detection module 300 into a parallel dual-column structure (columns A and B). When one column performs online calibration or self-cleaning, the system automatically switches to the other column to maintain online measurement without interrupting the overall detection process. This design satisfies the requirement for continuous online monitoring without affecting periodic quality control and maintenance operations, completely solving the pain point of traditional single-channel systems being unable to continuously measure during maintenance and calibration, and further improving the long-term reliability of the system. For example, when column A is performing online calibration or self-cleaning, the system can automatically switch to column B to handle sample delivery and detection tasks, ensuring uninterrupted detection. After column A completes calibration and purification and returns to standby mode, if column B needs to perform the corresponding operation, it can switch back to column A. The two columns alternate in rotation, working together to ensure continuous online monitoring.

[0042] In one embodiment, the sample introduction module 100 includes: The sample preparation and pretreatment unit is used to introduce a test liquid sample containing boric acid solution through a pipeline and to pretreat the test liquid sample; wherein, the pretreatment includes quantitative injection, filtration to remove impurities and acidity adjustment. The boric acid sample atomization unit is used to convert pretreated liquid samples into sample aerosols by means of one or more of a peristaltic pump, an atomizer, and / or atomizing chamber, according to flow control requirements.

[0043] In this embodiment, the sample introduction module 100 specifically includes a sample preparation and pretreatment unit and a boric acid sample atomization unit. The sample preparation and pretreatment unit introduces a high-temperature (300℃) and high-pressure (15.5MPa) boric acid solution through a pipeline, which is then cooled and depressurized via pipes, valves, heat exchangers, and throttling devices to bring the sample to the required room temperature, normal pressure, and low flow rate for detection. If the sample is turbid, suspended impurities are removed by filtration through a membrane filter. If the sample concentration is too high, it is diluted proportionally with a quantitative amount of deionized pure water to meet the requirements of subsequent measurement steps. The boric acid sample atomization unit converts the liquid sample into a sample aerosol using a peristaltic pump, atomizer, and a mist chamber, according to flow control requirements.

[0044] For example, in practical applications, when introducing a liquid sample to be tested, it is first connected through the existing pipeline of the original nuclear sampling system, without the need to lay additional main process pipelines. This allows for precise control of the sampling flow rate. Subsequently, the cooled and depressurized sample is passed into the filtration unit to remove suspended impurities that may clog the sample inlet pipeline. Then, the sample acidity is adjusted to a preset range by the online acidity adjustment unit, reducing the risk of boric acid crystallization from the source. After pretreatment, a peristaltic pump delivers the sample to the nebulizer at a set constant flow rate. With the assistance of the carrier gas, the nebulizer disperses the liquid sample into uniform and fine droplets. Only fine droplets that meet the particle size requirements can pass through the fog chamber into the microwave plasma torch generation module 200. Large droplets will condense on the fog chamber wall and be discharged as waste liquid. This ensures that the sample aerosol entering the plasma is uniform and stable, providing a reliable sample input basis for subsequent excitation and detection.

[0045] In one embodiment, the microwave plasma torch generating module 200 includes: The microwave generator unit is used to generate high-frequency microwave energy to provide an energy source for plasma formation. A gas control unit is used to control the flow rates of the working gas and the carrier gas to transport the sample aerosol; wherein the working gas includes any one or more of argon, nitrogen, and air; The plasma torch unit is used to form high-temperature microwave plasma on the sample aerosol, and to induce energy level transitions of element atoms or ions and emit characteristic spectra through the high-temperature microwave plasma.

[0046] In this embodiment, after receiving the sample aerosol, the microwave plasma torch generation module 200 first uses a gas control unit to stably control the flow rates of the carrier gas and working gas (such as argon, nitrogen, and air) according to preset parameters. The carrier gas transports the sample aerosol to the plasma torch unit. Simultaneously, the high-frequency microwave energy (e.g., 2.45 GHz) output by the microwave generator unit is introduced into the plasma torch unit through a coupling structure. Under the action of the microwave field within the torch, the working gas is ionized to form a stable high-temperature microwave plasma torch. After the sample aerosol enters the plasma torch with the carrier gas, it undergoes desolvation, evaporation, and atomization processes in a high-temperature environment. The atoms of the analyte further gain energy and undergo energy level transitions, ultimately emitting the characteristic spectrum of the corresponding element, which is then transmitted to the subsequent characteristic spectrum identification and concentration detection module 300. Throughout the process, the gas control unit stabilizes the gas pressure and flow rate in real time to avoid plasma jitter caused by airflow fluctuations, ensuring the continuous stability of the plasma torch's excitation state and providing support for obtaining high-intensity, low-noise characteristic spectra.

[0047] In this embodiment, the plasma torch tube can be a coaxial, wave-shaped structure with a high-temperature resistant integrated all-quartz structure. The overall structure is simple, compact, and easy to assemble and disassemble, facilitating daily maintenance and replacement. Simultaneously, the inner wall of the torch tube can be polished to reduce the adsorption and deposition of matrix impurities such as boron salts, thus reducing the cleaning burden on the subsequent self-cleaning module. Furthermore, an integrated water-cooling structure can be installed on the outside of the torch tube to promptly remove excess heat generated by microwave coupling, preventing deformation and damage due to high temperatures, further extending the service life of the components, and ensuring the long-term stable operation of the plasma torch.

[0048] In practical applications, the core workflow of the microwave plasma torch generating module 200 is mainly divided into four stages, as follows: (1) Start-up and pre-ionization: First, the gas control unit introduces working gas (such as argon) into the plasma torch tube until a stable gas flow environment is established; after the gas pressure in the torch tube reaches the preset standard, the microwave generator starts and outputs microwaves. The microwaves are introduced into the plasma torch tube through the transmission system. The strong electric field breaks down the working gas instantly, generating a small number of "seed" electrons to complete the plasma ignition operation.

[0049] (2) Power Coupling and Maintenance: The "seed" electrons oscillate violently under the action of the microwave electric field. During the oscillation, they collide with gas molecules, transferring energy to the gas molecules and triggering an avalanche ionization reaction. The core task of the control system at this stage is to match the output power of the microwave generator with the load impedance of the plasma torch tube to ensure efficient deposition of microwave energy, thereby forming and maintaining a high-temperature and high-density plasma torch.

[0050] (3) Airflow and thermal management: Plasma torches typically employ a multi-layered concentric tube structure, with different layers of airflow serving different functions: the outer protective gas forms an air curtain, cooling and confining the plasma to prevent the quartz torch from burning out due to high temperatures; the central carrier gas or middle-layer auxiliary gas is used to transport the test sample (suitable for scenarios such as spectral analysis). The gas control unit precisely adjusts the gas flow rate of each layer, effectively protecting the torch and accurately shaping the plasma morphology to ensure testing requirements.

[0051] (4) Closed-loop feedback and protection: During the operation of the plasma torch, if the reflected power of the torch tube suddenly increases due to impedance mismatch, or if the torch tube overheats due to gas flow interruption, the control system will immediately issue a command to control the microwave generator to automatically cut off the microwave output, and at the same time trigger the audible and visual alarm mechanism to avoid equipment damage. Under normal operating conditions, the system will also dynamically fine-tune the microwave power and the gas flow rate of each level to ensure the continuous and stable operation of the plasma torch.

[0052] The functions of each component in this module can be further clarified through analogy: the microwave generator is equivalent to an engine, providing energy for the generation and maintenance of the plasma torch; the gas control unit is equivalent to a fuel supply and cooling system, responsible for delivering working gas and cooling the torch tube; the plasma torch tube is equivalent to a combustion chamber and nozzle, which is the core carrier for the formation and operation of the plasma torch. The three work together to achieve the stable maintenance of the plasma torch by stably supplying working gas and continuously outputting energy.

[0053] The typical cycle of this module in actual operation is as follows: Start the main control system → The gas control unit introduces the working gas and sets the preset gas pressure and flow rate → The microwave generator starts and completes the ignition operation in low power mode → After the plasma torch stabilizes, the microwave output power is gradually increased → The gas flow rate of each level is adjusted to shape the plasma morphology that meets the detection requirements → The system continuously monitors key parameters such as reflection power and torch temperature → During operation, the microwave power, gas flow rate and other related parameters are automatically adjusted according to parameter changes to ensure stable operation of the module.

[0054] In one embodiment, the feature spectrum recognition and concentration detection module 300 includes: Background acquisition unit, used to pre-acquire the background spectrum of the plasma; A sample spectral acquisition unit is used to acquire the characteristic spectrum through a filtering method; The data processing unit is used to combine the background spectrum and the characteristic spectrum, convert them into an analog quantity of boron concentration through linear transformation, and set the analog quantity as the boron concentration data.

[0055] Furthermore, the data processing unit includes: An isotope processing unit is used to obtain the average wavelength of boron isotopes and perform analog quantity conversion based on the average wavelength; wherein the boron isotopes include 10 B and 11 B; And used in isotopes 10 When the abundance of B decreases to a preset abundance threshold, it is detected by isotope analysis. 10 B and 11 The characteristic spectral line differences of B correct the analog quantity.

[0056] In this embodiment, when the characteristic spectrum identification and concentration detection module 300 performs identification and detection, the background acquisition unit first acquires the background spectrum of the plasma in advance, which is used to subtract the spectral interference caused by the environmental background. Then, the sample spectrum acquisition unit accurately separates the characteristic spectrum of boron (in other embodiments, it can also be processed for other elements to be measured) through a specific filtering method, such as a smoothing filtering method. Finally, the data processing unit combines the pre-acquired background spectrum to subtract interference, performs linear transformation according to the established standard curve, calculates the concentration data of the corresponding element, and converts the concentration data into a transmittable analog quantity (e.g., a 4-20mA analog quantity) and outputs it to the upper monitoring system.

[0057] For boron detection, the data processing unit first obtains two isotopes of boron. 10 B and 11 The characteristic spectral wavelengths of B are used to calculate the average wavelength of boron, and then the concentration is converted based on the average wavelength; at the same time, the operation of nuclear power plants is taken into account. 10 B will be continuously consumed, therefore when 10 When the abundance of boron drops to a preset threshold, the concentration calculation results are corrected by using the difference in the intensity of the characteristic spectral lines of the two isotopes, ensuring that the boron concentration measurement results are always accurate.

[0058] Specifically, the processing of boron isotopes needs to be combined with their atomic characteristics and spectral detection patterns: due to the small atomic weight of boron, its two isotopes ( 10 B and 11 The mass difference between B) produces a measurable spectral line shift, known as the isotope effect. However, in atomic emission spectroscopy, this spectral line shift is extremely small—for example, in the 345 nm wavelength region, the shift is typically on the order of 0.001 nm or less, far below the resolution of conventional spectrometers. Therefore, in practical detection applications, there is no need to [further details needed]. 10 B and 11 B is distinguished separately, usually by directly using the average wavelength of the characteristic spectral lines of the two isotopes for analysis. The system can be based on the boric acid solution... 10 The actual abundance of B, independently completing the total boron concentration and 10 Calculation of B concentration.

[0059] Here, there are three commonly used analytical spectral lines for boron, as follows: 249.677 nm is the most commonly used analytical line, with moderate intensity and less interference; 249.772 nm is another strong spectral line, often used in conjunction with 249.677 nm for qualitative and quantitative analysis of boron; and 208.889 nm has a relatively low intensity and is only selected under specific analytical conditions.

[0060] As the reactor continues to operate 10 B will be continuously consumed, and its abundance will decrease, especially towards the end of the reactor's lifespan. 10 B abundance drops to its lowest level. At this point, it is necessary to utilize... 10 B and 11 The characteristic spectral line differences of B correct the concentration calculation results to ensure measurement accuracy. For example, at the 208.959 nm atomic spectrum line, the maximum difference between the spectral lines of the two isotopes is 0.02 angstroms (i.e., 0.002 nm, 1 angstrom = 0.1 nanometer, where angstrom represents a unit of length). This difference can be used to calculate the concentration. 10 The real-time abundance of B, and thus the total boron concentration and 10 The calculated concentration of B. Compared to existing technologies that can only measure... 10 B. The limitation of not requiring correction is addressed in this embodiment, where the correction logic is as follows: Based on the initial stage of reactor operation... 10 Using B abundance (e.g., 35%) as the initial baseline, and combining it with the abundance at the end of the run (e.g., 33%), according to... 10 A formula was established to determine the decreasing pattern of B abundance, and the interpolation method was used to calculate the abundance at different stages of reactor operation. 10 B abundance, completing concentration correction.

[0061] It should be noted that, 10 B and 11 The wavelength differences caused by the superposition of characteristic spectral lines B cannot be distinguished by conventional instruments. Based on the requirements of spectral analysis, three core resolvable boron isotope spectral lines can be selected, and their wavelengths, isotope shifts, and unit conversion relationships can be clearly defined. These lines can be directly used for spectral analysis, as detailed below: First, the B II ion line (345.1 nm, with the largest isotopic shift, is the preferred spectral line), whose vacuum wavelength (Å) is: 10 B-3451.3876 Å (equivalent to 345.13876 nm). 11 B-3451.2819 Å (equivalent to 345.12819 nm), with an isotopic difference Δλ=0.1057Å (i.e. 10.57 pm), is the most easily distinguishable boron isotope line in spectral analysis.

[0062] Second, the BI atomic line (208.96 nm, secondary choice, located in the ultraviolet region), its vacuum wavelength (Å) is: 10 B-2089.625 Å (equivalent to 208.9625 nm). 11 B-2089.600 Å (equivalent to 208.9600 nm), isotopic difference Δλ=0.025Å (i.e. 2.5 pm).

[0063] Thirdly, the BI atomic line (249.68 nm, with a relatively weak displacement, suitable for routine analysis) has a vacuum wavelength (Å) of: 10 B-2496.811 Å (equivalent to 249.6811 nm). 11 B-2496.800 Å (equivalent to 249.6800 nm), isotopic difference Δλ=0.011Å (i.e. 1.1 pm).

[0064] This embodiment completes concentration calculation and correction by screening suitable isotope spectral lines, eliminating the need for a special ultra-high resolution spectrometer, thus controlling equipment costs, while also adapting to the boron concentration detection requirements throughout the reactor's entire lifespan, ensuring measurement accuracy at different operational stages. In practical applications, in addition to boron, the system can also identify and quantify the characteristic spectra of other elements such as lithium and zinc in the sample based on preset parameters. Only the establishment of standard curves for the corresponding elements in advance is required to complete simultaneous multi-element detection, without additional hardware adjustments. This fully leverages the technical advantages of atomic emission spectroscopy for simultaneous multi-element analysis, meeting the online monitoring needs of nuclear power plants for the content of multiple elements in the primary coolant.

[0065] like Figure 2 As shown, this embodiment of the invention also provides a method for detecting online boron concentration in a nuclear power plant, which is applied to the detection of online boron concentration in a nuclear power plant as described above. The method includes steps S101 to S103.

[0066] Step S101: Pre-treat the test liquid sample containing boron water sample to obtain sample aerosol, and transport the sample aerosol to the reaction end; Step S102: A high-temperature microwave plasma torch is formed on the sample aerosol through microwave field coupling, and then a characteristic spectrum is generated by excitation through the high-temperature microwave plasma torch; Step S103: Qualitatively identify and quantitatively calculate the characteristic spectrum to obtain the corresponding boron concentration data.

[0067] In one embodiment, the step of forming a high-temperature microwave plasma torch from the sample aerosol through microwave field coupling, and then generating a characteristic spectrum by excitation through the high-temperature microwave plasma torch, includes: High-frequency microwave energy is generated by a microwave generator unit to provide an energy source for plasma formation. The sample aerosol is transported by controlling the flow rates of the working gas and the carrier gas; wherein the working gas includes any one or more of argon, nitrogen, and air; High-temperature microwave plasma is formed on the sample aerosol by a plasma torch, and the high-temperature microwave plasma causes element atoms or ions to undergo energy level transitions and emit characteristic spectra.

[0068] In one embodiment, the step of qualitatively identifying and quantitatively calculating the characteristic spectrum to obtain the corresponding boron concentration data includes: Pre-collection of the plasma background spectrum; The characteristic spectrum is acquired using a filtering method; By combining the background spectrum and the characteristic spectrum, a simulated value of boron concentration is calculated through linear transformation, and this simulated value is set as the boron concentration data.

[0069] Since the embodiments of the method section correspond to the embodiments of the system section, please refer to the description of the embodiments of the system section for the embodiments of the method section, and they will not be repeated here.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0071] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A system for detecting boron concentration in a nuclear power plant online, characterized in that, include: The sample introduction module is used to pretreat the test liquid sample containing boron water sample to obtain sample aerosol, and to transport the sample aerosol to the reaction end; The microwave plasma torch generating module is used to receive the sample aerosol delivered by the sample introduction module, and to form a high-temperature microwave plasma torch on the sample aerosol through microwave field coupling, and then to generate characteristic spectra through the high-temperature microwave plasma torch. The feature spectrum identification and concentration detection module is used to collect the feature spectrum and perform qualitative identification and quantitative calculation on the feature spectrum to obtain the corresponding boron element concentration data.

2. The online boron concentration detection system for nuclear power plants according to claim 1, characterized in that, Also includes: An online verification module is used to monitor and verify the overall boron concentration detection process; wherein, the monitoring and verification methods include inserting standard substances, blank controls, and signal drift correction.

3. The online boron concentration detection system for nuclear power plants according to claim 1, characterized in that, Also includes: An online self-cleaning module is used to clean crystallized and deposited impurities in the sample introduction module and the microwave plasma torch generation module; wherein the cleaning process includes online acid washing, plasma burn-off, and pipeline purging.

4. The online boron concentration detection system for nuclear power plants according to claim 1, characterized in that, The microwave plasma torch generation module and the characteristic spectrum recognition and concentration detection module operate in parallel.

5. The online boron concentration detection system for nuclear power plants according to claim 1, characterized in that, The sample introduction module includes: The sample preparation and pretreatment unit is used to introduce a test liquid sample containing boric acid solution through a pipeline and to pretreat the test liquid sample; wherein, the pretreatment includes quantitative injection, filtration to remove impurities and acidity adjustment. The boric acid sample atomization unit is used to convert pretreated liquid samples into sample aerosols by means of one or more of a peristaltic pump, an atomizer, and / or atomizing chamber, according to flow control requirements.

6. The method for detecting boron concentration in a nuclear power plant according to claim 1, characterized in that, The microwave plasma torch generating module includes: The microwave generator unit is used to generate high-frequency microwave energy to provide an energy source for plasma formation. A gas control unit is used to control the flow rates of the working gas and the carrier gas to transport the sample aerosol; wherein the working gas includes any one or more of argon, nitrogen, and air; The plasma torch unit is used to form high-temperature microwave plasma on the sample aerosol, and to induce energy level transitions of element atoms or ions and emit characteristic spectra through the high-temperature microwave plasma.

7. The method for detecting boron concentration in a nuclear power plant according to claim 6, characterized in that, The feature spectrum recognition and concentration detection module includes: Background acquisition unit, used to pre-acquire the background spectrum of the plasma; A sample spectral acquisition unit is used to acquire the characteristic spectrum through a filtering method; The data processing unit is used to combine the background spectrum and the characteristic spectrum, convert them into an analog quantity of boron concentration through linear transformation, and set the analog quantity as the boron concentration data.

8. The method for detecting boron concentration in a nuclear power plant according to claim 7, characterized in that, The data processing unit includes: An isotope processing unit is used to obtain the average wavelength of boron isotopes and perform analog quantity conversion based on the average wavelength; wherein the boron isotopes include 10 B and 11 B; And used in isotopes 10 When the abundance of B decreases to a preset abundance threshold, it is detected by isotope analysis. 10 B and 11 The characteristic spectral line differences of B correct the analog quantity.

9. A method for detecting online boron concentration in a nuclear power plant, applied to the detection of online boron concentration in a nuclear power plant as described in any one of claims 1-8, characterized in that, The method includes: The test liquid sample containing boron water is pretreated to obtain a sample aerosol, and the sample aerosol is then transported to the reaction end. A high-temperature microwave plasma torch is formed on the sample aerosol through microwave field coupling, and then the high-temperature microwave plasma torch is used to excite and generate characteristic spectra. The characteristic spectra are qualitatively identified and quantitatively calculated to obtain the corresponding boron concentration data.

10. The method for detecting boron concentration in a nuclear power plant according to claim 9, characterized in that, The process of forming a high-temperature microwave plasma torch from the sample aerosol through microwave field coupling, and then generating a characteristic spectrum by excitation through the high-temperature microwave plasma torch, includes: High-frequency microwave energy is generated by a microwave generator unit to provide an energy source for plasma formation. The sample aerosol is transported by controlling the flow rates of the working gas and the carrier gas; wherein the working gas includes any one or more of argon, nitrogen, and air; High-temperature microwave plasma is formed on the sample aerosol by a plasma torch, and the high-temperature microwave plasma causes element atoms or ions to undergo energy level transitions and emit characteristic spectra.

11. The method for detecting boron concentration in an online nuclear power plant according to claim 10, characterized in that, The qualitative identification and quantitative calculation of the characteristic spectrum to obtain the corresponding boron concentration data includes: Pre-collection of the plasma background spectrum; The characteristic spectrum is acquired using a filtering method; By combining the background spectrum and the characteristic spectrum, a simulated value of boron concentration is calculated through linear transformation, and this simulated value is set as the boron concentration data.

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