An online measurement system for total radioactivity and nuclides of water body

Abstract

The present application relates to the technical field of nuclear radiation monitoring, in particular to a kind of water total radioactivity and nuclide online measurement system, comprising: gamma detector, beta detector, alpha detector and water treatment component, the water treatment component extracts water sample and processes after passing through the gamma detector, beta detector and alpha detector, the gamma detector is arranged in the first shielding body, the beta detector and the alpha detector are arranged in the second shielding body;Water treatment component provided by the present application is responsible for extracting and processing water sample, so that it passes through various detectors in turn, gamma detector obtains the gamma energy spectrum of water sample, beta detector and alpha detector obtain the beta and alpha total activity of water sample, to realize the accurate detection of different types of radiation.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation monitoring technology, specifically to an online measurement system for total radioactivity and nuclides in water. By integrating multiple types of radiation detectors, it is used to monitor the α, β, and γ radioactivity activities and nuclide types in water in real time. Its application scope includes online monitoring and threshold alarms for radiation levels in water bodies such as nuclear facilities, drinking water, and industrial wastewater, thereby improving the ability to quickly detect and respond to water radiation pollution. Background Technology

[0002] With the development of nuclear energy utilization and nuclear technology, monitoring radionuclides in water bodies has become a critical requirement for environmental protection, especially in the field of nuclear emergency response. Currently, various low-background radioactivity measurement systems have been developed both domestically and internationally. However, most existing systems employ offline sampling and analysis techniques, such as liquid scintillation counters (LSCs). While these systems can effectively detect alpha and beta activities in water samples, they require manual sampling and laboratory analysis, making them unsuitable for real-time monitoring. The TAWARA_RTM system, developed abroad, enables real-time online monitoring of radioactivity in tap water; however, its equipment is expensive, maintenance costs are high, and it has limitations in nuclide identification, failing to simultaneously monitor multiple types of radiation in real time.

[0003] Research and application of online monitoring of radioactivity in water bodies in China is relatively lagging, mainly relying on laboratory analytical methods for measuring total radioactivity and nuclides, which cannot reflect the radioactivity level of water bodies in real time. Therefore, there is a need for an efficient, accurate, and economical online measurement system to meet the practical application requirements for rapid detection of radioactive pollution in water bodies.

[0004] Based on this, the present invention proposes an online measurement system for total radioactivity and nuclides in water bodies, enabling comprehensive and real-time monitoring of radioactive pollution in water bodies. Summary of the Invention

[0005] The technical problem to be solved by this invention is that existing methods for detecting radioactivity and nuclides in water cannot meet the requirements for real-time online monitoring, and there are insufficient accuracy issues in nuclide identification and low-background measurement. The purpose is to provide an online measurement system for total radioactivity and nuclides in water, which realizes real-time and accurate measurement of α, β, and γ radioactivity activities and nuclide types in water, and has low-background and high-precision monitoring capabilities, enabling continuous monitoring of water radiation pollution and alarms for exceeding thresholds.

[0006] This invention is achieved through the following technical solution:

[0007] An online measurement system for total radioactivity and nuclides in water includes: a gamma detector, a beta detector, an alpha detector, and a water treatment component. The water treatment component extracts and processes water samples before passing them through the gamma detector, beta detector, and alpha detector. The gamma detector is housed within a first shielding body, and the beta detector and alpha detector are housed within a second shielding body.

[0008] The gamma detector acquires the gamma energy spectrum of the water sample, the beta detector acquires the total beta activity of the horizontal sample, and the alpha detector acquires the total alpha activity of the horizontal sample.

[0009] Specifically, the water treatment assembly includes a peristaltic pump, a particle filter, and an ultraviolet generator. The input end of the peristaltic pump is connected to the water body, the output end of the peristaltic pump is connected to the input end of the particle filter, the output end of the particle filter pump is connected to the input end of the ultraviolet generator, the output end of the ultraviolet generator is connected to the input end of the gamma detector disposed in the first shield, the output end of the gamma detector is connected to the input end of the beta detector disposed in the second shield, the output end of the beta detector is connected to the input end of the alpha detector disposed in the second shield, and the output end of the alpha detector is connected to the water body.

[0010] Furthermore, a flow meter and a pressure gauge are optionally installed at positions between the γ detector, the β detector, the α detector, and the water treatment component.

[0011] Specifically, the first shield has a cavity inside, and a shielding water tank is installed inside the cavity. The gamma detector is installed inside the shielding water tank. Both the first shield and the shielding water tank are provided with a water inlet and a water outlet that connect to the gamma detector. The water inlet is connected to the output end of the water treatment component, and the water outlet is connected to the input end of the beta detector.

[0012] Optionally, the gamma detector includes a main detector and an anti-coincidence detector. The main detector is provided with a central waterway connecting the waterway inlet and the waterway outlet. The anti-coincidence detectors are arranged in a ring, and the main detector is disposed within the anti-coincidence detectors.

[0013] The main detector is a large-volume NaI detector and a main photomultiplier tube, and the main photomultiplier tube is coupled to the large-volume NaI detector;

[0014] The anti-coincidence detector includes a NaI ring crystal array and a first photomultiplier tube, wherein multiple first photomultiplier tubes are respectively coupled to multiple scintillation crystals in the NaI ring crystal array.

[0015] Specifically, the second shield is provided with a β placement cavity inside, and the β detector is disposed inside the β placement cavity;

[0016] The β detector includes: a plastic scintillator plate and a second photomultiplier tube. The two plastic scintillator plates are arranged in parallel, and the inner sides of the two plastic scintillator plates form a β measurement chamber. The input end of the β measurement chamber extends out of the β placement cavity and communicates with the output end of the γ detector. The output end of the β measurement chamber extends out of the β placement cavity and communicates with the input end of the α detector.

[0017] Multiple second photomultiplier tubes are respectively disposed on the outer side of the plastic scintillator plate.

[0018] Optionally, the β measuring chamber is sealed on all sides, and the surface of the plastic scintillator plate is covered with a PMMA protective film.

[0019] Specifically, the second shield is provided with an α placement cavity inside, and the α detector is disposed inside the α placement cavity;

[0020] The α detector includes: a micro-scintillator, a light guide support, and a third photomultiplier tube. The interior of the light guide support is an α measurement chamber, and multiple micro-scintillators are distributed within the α measurement chamber. The input end of the α measurement chamber extends out of the α placement cavity and communicates with the output end of the β detector. The output end of the α measurement chamber extends out of the α placement cavity and connects to the water body.

[0021] Multiple third photomultiplier tubes are respectively disposed on the outside of the light guide support.

[0022] Furthermore, the system also includes a water sample retention component. The output of the α detector is connected to the water sample retention component and the water body respectively through a three-way pipe. A switch valve is provided at the inlet of the water sample retention component.

[0023] Optionally, the flow rate of the peristaltic pump is 10 L / min.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] The water treatment component provided by this invention is responsible for extracting and processing water samples, which are then passed through various detectors in sequence. A gamma detector obtains the gamma spectrum of the water sample, and a beta detector and an alpha detector obtain the beta and alpha total activities of the water sample, respectively, thereby achieving accurate detection of different types of radiation.

[0026] This invention enables real-time online monitoring of γ, β, and α radiation in water bodies, improving the timeliness and accuracy of water radiation pollution detection. Furthermore, it employs a multi-probe design and physical shielding technology to effectively reduce background radiation interference, ensuring low background and high sensitivity in the measurement. Attached Figure Description

[0027] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, but do not constitute a limitation on the embodiments of the present invention.

[0028] Figure 1 This is a schematic diagram of the structure of an online measurement system for total radioactivity and nuclides in water, as described in this invention.

[0029] Figure 2 This is a schematic diagram of the gamma detector according to the present invention.

[0030] Figure 3 This is a schematic diagram of the structure of the β detector according to the present invention.

[0031] Figure 4 This is a schematic diagram of the structure of the α detector according to the present invention.

[0032] Figure 5 This is a schematic diagram of a plastic scintillator plate excited by radioactive particles in water, according to the present invention.

[0033] Figure 6 This is a schematic diagram of the excited light of a particle scintillator according to the present invention.

[0034] Figure 7 This is a block diagram of the mechanism of an online measurement system for total radioactivity and nuclides in water, as described in this invention.

[0035] Figure reference numerals: 1-particle filter, 2-ultraviolet generator, 3-flow meter, 4-first shield, 5-shielded water tank, 6-gamma detector, 7-pressure gauge, 8-second shield, 9-β detector, 10-alpha detector;

[0036] 61-NaI ring crystal array, 62-first photomultiplier tube, 91-plastic scintillator plate, 92-second photomultiplier tube, 101-light guide support, 102-third photomultiplier tube, 103-microparticle scintillator. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0038] It should also be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0039] Where there is no conflict, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] With the rapid development of nuclear energy and nuclear technology utilization in my country, researching methods and devices for rapidly measuring radionuclides in water bodies has become an urgent need in my country's environmental monitoring, especially in nuclear emergency situations. Therefore, it is necessary to conduct uninterrupted environmental monitoring of radionuclides in water bodies.

[0041] Total radioactivity and nuclide measurement in water is a low-background measurement technique. Online analysis of total radioactivity and nuclide measurement began earlier abroad, and various low-background measurement systems have been developed and widely applied both domestically and internationally, with related research and experimental work conducted. The earliest low-background radioactivity measurement systems used a flow-gas proportional counter as the detection element. A typical example is the MPC-9604 low-background counter manufactured by ORTEC Corporation in the United States, which uses a flow-gas proportional counter with P10 gas (90% argon and 10% methane) as the working gas. It has a simple structure and stable performance. The iMac low-background activity analyzer developed by CANBERRA Corporation uses two detection elements: a PIPS semiconductor detector and a plastic scintillator detector. The PIPS detector is used to detect alpha and beta particles, while the plastic scintillator detector acts as an anti-coincidence detector to subtract interference from cosmic rays.

[0042] In summary, detectors used in low-background measurement systems include gas detectors (proportional counters), scintillator detectors (mainly composite scintillators combining plastic scintillators and zinc sulfide scintillators), and semiconductor detectors (gold-silicon surface barrier detectors, PIPS detectors).

[0043] To achieve rapid detection, international standards have proposed using liquid scintillator methods for the analysis of standard water samples, tap water, and drinking water. The Nuclear Science Institute of Ankara University in Turkey followed this method and calculated the minimum detectable concentrations (MDCs) of total alpha and total beta, achieving good results. Subsequently, they used liquid scintillation spectroscopy (LSS) to simultaneously determine the concentrations of total alpha and total beta in drinking water, verifying the effectiveness of the method and demonstrating good accuracy and precision. LSS technology can be used for the rapid screening of samples with excessive radioactive substances, providing a basis for the rapid assessment of the radioactive content of samples. The Polytechnic University of Valencia in Spain mixed water samples with liquid scintillator and measured them using a low-background scintillation counter / ultra-low-background liquid scintillation spectrometer, Quantulas 1220. This method can analyze samples with different salinity and pH values, and can complete radioactive contamination assessment within 2 hours, enabling a rapid and accurate response in emergency situations.

[0044] Liquid scintillation counters (LSCs) can be used to monitor alpha and beta radioactivity in water in a timely manner. However, LSCs are an offline technology that requires water samples to be collected and mixed with the liquid scintillation material for measurement, so they are not suitable for real-time monitoring.

[0045] Currently, only the European Union has developed a real-time online monitoring system for radioactivity in tap water, abbreviated as TAWARA_RTM. The research team has conducted corresponding research and testing on detector performance and system measurement, achieving good online analysis results. The TAWARA_RTM system is used for real-time monitoring of radioactive pollution in water, providing timely early warnings of radioactivity exceeding limits and nuclide identification. As shown in the figure, the TAWARA_RTM system consists of three parts: an Early Alarm Detector (EAD) for early monitoring of gamma radioactivity in water; a Real-Time Monitor (RTM) for continuous monitoring of total alpha and beta radioactivity in water; and a Spectroscopic Detector (SPEC) for identifying and quantifying radionuclides. The detector in the RTM uses an EJ-444 plastic scintillator. EJ-444 consists of a 20 μm thick layer of ZnS(Ag) phosphor deposited on a thin plastic scintillator layer (EJ-212). The ZnS(Ag) layer is used to detect alpha particles, and the plastic scintillator layer is used to detect beta particles. To prevent direct contact between the crystal material and water, a PMMA thin film is coated on the outermost layer of the detector. The EJ-444 plastic scintillator is very thin and almost insensitive to gamma rays.

[0046] In China, the measurement and analysis of total radioactivity mainly relies on the national standard method—the thick source method and the evaporation and concentration method. At the same time, there are also studies on measuring total radioactivity using liquid flashover. Overall, the online monitoring and analysis of total radioactivity in water bodies is still relatively backward.

[0047] Some basic research has been conducted in China on the rapid and timely measurement of alpha and beta radioactivity in water bodies. The University of Science and Technology of China (USTC) has developed a device for rapid monitoring of radionuclides in water bodies, using a liquid scintillator. In the event of an emergency, it can quickly measure and analyze alpha and beta nuclides in the target water body without requiring water sample concentration or other processing. However, it cannot measure total radioactivity. Tsinghua University has designed an online monitoring device for total beta in drinking water. This device's detector is constructed from 1096 scintillator optical fibers, each 50cm long and 1mm in diameter, achieving continuous online measurement of total beta, but it has not been able to achieve online measurement of alpha and gamma. In recent years, China has successively carried out investigations and studies on the concentration of natural radionuclides in inland water bodies. However, the investigation methods are basically based on fixed-point sampling and laboratory analysis, which consumes a lot of human, material, and financial resources, and the monitoring results have large deviations.

[0048] To address the need for online measurement and analysis of total radioactivity in water bodies, a real-time online measurement system centered on a thin plastic scintillator array detector needs to be established to control the background and achieve a good minimum detectable activity index, thereby enabling real-time online measurement and analysis of total radioactivity in water bodies.

[0049] Foreign technologies are mature and reliable, leading the market in their respective fields and holding a high market share, but their prices are also high. Currently, there is no mature and reliable online measurement system for total radioactivity and nuclides in water bodies in China, and the functionality and performance of domestically produced similar products urgently need development to meet market demands.

[0050] This invention proposes a monitoring system for continuous monitoring of αβγ radioactivity in water. It directly performs online measurements on the water body under test, rapidly measures and analyzes the total αβγ radioactivity level in the water in real time, issues alarms when thresholds are exceeded, and monitors water quality changes in real time, thereby achieving continuous monitoring of total radioactivity and nuclides in water.

[0051] Currently, the international online monitoring technology (EU TAWARA_RTM) uses a large-size single detector coated with a micron-sized ZnS:Ag luminescent layer to distinguish between α and β particles. This method can only measure the total intensity of nuclides and cannot perform nuclide identification simultaneously with real-time monitoring. A separate gamma-ray spectrometer (SPEC) is required for nuclide identification, which is costly and technically challenging. Furthermore, damage to the ZnS:Ag coating prevents the identification of α particle signals, necessitating the replacement of the entire detector and posing a risk of high maintenance costs. On the other hand, although the light signals generated by the two luminescent layers have different emission peaks that can be used to distinguish particle types, the emission spectra overlap, resulting in significant crosstalk between the two signals and raising concerns about measurement accuracy. Moreover, this system only reduces the gamma background by decreasing the thickness of the plastic scintillator without further optimization. Currently, the liquid scintillator technology used domestically can only identify nuclides and cannot measure total α and β emissions in real time; the fiber optic technology can continuously measure total β online, but cannot achieve online measurement of α.

[0052] Compared to single-probe αβ activity monitoring, this invention utilizes the interaction characteristics of α and β particles with matter. By employing a shared-channel multi-probe approach for separate measurements of the two particle types, spectral isolation can be achieved. In a lead chamber, NaI(Tl) is used to measure gamma rays to identify nuclides and their corresponding activities. This technology is highly mature, featuring fast channel response, accurate identification, and low crosstalk ratio. Compared to domestic liquid scintillator and fiber optic technologies, this invention enables real-time measurement of dynamic flowing water, providing accurate information on the total radioactivity and nuclides in the water.

[0053] In nature, water is the main medium for transporting radioactive substances. During the decay process, radioactive substances may emit α, β, and γ rays simultaneously. Although the ranges of α and β rays are much smaller than that of γ rays, they have strong ionization capabilities. Once they enter the human body, they will cause internal irradiation to the human body, posing a great threat to physical health. Therefore, radioactive measurement of nuclides in water bodies is of great significance.

[0054] In the "Classification of Radioactive Wastes" standard, radioactive pollutants are classified into exempt radioactive pollutants, low-level radioactive pollutants (≤4×106 Bq / L), medium-level radioactive wastes (4×106 Bq / L < c ≤ 4×1010 Bq / L), and high-level radioactive pollutants (>4×1010 Bq / L) according to their radioactive activity concentration levels. Since radioactive liquid waste contains a large amount of radioactive nuclides, once it enters the human body through various channels, it will deposit in various organs of the body and cause internal irradiation, which will not only affect human health and life but also damage the ecological environment. Therefore, it is necessary to strictly monitor and treat the generated radioactive wastewater to make its concentration meet the corresponding discharge standards before discharging it into the surrounding receiving water bodies.

[0055] The national standard "Hygienic Standard for Drinking Water" (GB5749-2006) stipulates that the guiding values for radioactive indicators in drinking water are a maximum total α activity of 0.5 Bq / L and a maximum total β activity of 1.0 Bq / L. The purpose is to ensure that the annual irradiation dose equivalent received by each person is below 0.1 mSv / a when consuming 2 L of water per day; the national standard "Integrated Wastewater Discharge Standard" (GB8978-1996) stipulates that for the discharge of sewage containing radioactive substances, the maximum total α activity is 1.0 Bq / L and the maximum total β activity is 10 Bq / L.

[0056] At present, the construction of water body radioactive monitoring systems in China is not yet perfect. For the monitoring of total α radioactivity and total β radioactivity in inland water bodies and marine water bodies, the commonly used methods are on-site investigation sampling methods and laboratory energy spectrum analysis methods. Among them, laboratory analysis mostly involves stirring, evaporating, and sample preparation of water samples according to national standard methods, and then using a low-background αβ measurement device to measure and analyze the total α and total β contents, which requires a lot of manpower and material resources and has a complex procedure. Due to reasons such as a long sampling period, cumbersome operation steps, and poor timeliness of measurement and analysis, these two methods cannot give the total radioactivity and nuclides of the water body to be measured in real time, making the monitoring results unable to reflect the total αβ radioactivity level of the target water body in real time.

[0057] The present invention can be used in water treatment plants, sewage treatment plants, hydrological monitoring stations, reservoirs, offshore fishing grounds, industrial facilities discharging wastewater, nuclear power plants, fire departments, and chemical defense forces, etc.

[0058] The online measurement system for total radioactivity and nuclides in water bodies directly performs real-time online measurements of the water body to be tested. It can meet the needs of real-time measurement of the water body to be tested on site. It is of great significance for improving the efficiency of real-time monitoring of total radioactivity in drinking water and wastewater, and strengthening the monitoring of total radioactivity and nuclides in environmental water resources. It has important social value and economic benefits, and has broad application prospects.

[0059] For scenarios such as domestic tap water, industrial and medical wastewater, lakes and oceans in my country, there is a need for a device that can rapidly measure the radioactivity and nuclides in water bodies in real time. This device would be used to assess the degree and type of radioactive contamination in the water, and based on this assessment, to make rapid emergency responses to radioactive contamination and reduce losses to the country and its people in the event of an accident.

[0060] Example 1

[0061] like Figure 1 As shown, an online measurement system for total radioactivity and nuclides in water includes: a gamma detector 6, a beta detector 9, an alpha detector 10, and a water treatment component. The water treatment component extracts and processes water samples before passing them through the gamma detector 6, beta detector 9, and alpha detector 10. The gamma detector 6 is installed inside a first shield 4, and the beta detector 9 and alpha detector 10 are installed inside a second shield 8.

[0062] γ detector 6 acquires the γ energy spectrum of the water sample, β detector 9 acquires the β total activity of the horizontal sample, and α detector 10 acquires the α total activity of the horizontal sample.

[0063] The water treatment unit first extracts samples from the water body and performs preliminary treatments, such as filtering impurities and eliminating microorganisms. The treated water samples then sequentially pass through the system's gamma detector 6, beta detector 9, and alpha detector 10 to measure the radioactivity of gamma rays, beta rays, and alpha rays, respectively. The gamma detector 6 is housed within a first shield 4 to shield against external radiation interference and to acquire the gamma energy spectrum of the water sample. The energy spectrum refers to the measurement of the energy distribution of gamma rays to identify and quantitatively analyze the radioactive characteristics of different nuclides in the sample.

[0064] The β detector 9 and α detector 10 are housed within a second shield 8, which also serves to reduce the influence of external radiation, thereby ensuring the accuracy of the measurements. The β detector 9 is primarily responsible for measuring the total β activity of the water sample, i.e., the total radioactivity of β particles; while the α detector 10 is used to measure the total α activity, i.e., the total radioactivity of α particles.

[0065] In this embodiment, real-time monitoring is achieved by extracting environmental water samples to form a circulating water path within the system. Therefore, the main interference during the detection process is the background radiation generated by radioactive nuclides in the external water body on the internal detector. The overall structural design requires the use of a shield of a certain thickness as the outer shell of the measurement chamber to reduce the influence of nuclides outside the measurement unit. The shield is a material used to absorb or block external radiation interference to ensure that the detector only measures radiation from the sample.

[0066] Materials commonly used for shielding include lead, concrete, steel, polyethylene, tungsten, etc. The shielding in this embodiment usually refers to one or a combination of these materials.

[0067] In this system, the water treatment component first ensures the purity of the water sample to reduce measurement errors. The gamma detector 6 utilizes a combination of a photomultiplier tube and a scintillation crystal to acquire the gamma energy spectrum by detecting photons generated from the interaction of gamma rays with the crystal. The beta and alpha detectors 10 obtain the corresponding total activity data by measuring the interaction of beta and alpha particles in the water sample with the plastic scintillator or other sensitive materials. The entire system uses a shield to reduce interference from external background radiation, thereby ensuring the accuracy and sensitivity of the measurement results.

[0068] To ensure purity and provide high-precision and high-sensitivity detection conditions for online measurement of total radioactivity and nuclides in water, the water treatment component includes: a peristaltic pump, a particle filter 1, and an ultraviolet generator 2. The input end of the peristaltic pump is connected to the water body, and the output end of the peristaltic pump is connected to the input end of the particle filter 1. The output end of the particle filter pump is connected to the input end of the ultraviolet generator 2. The output end of the ultraviolet generator 2 is connected to the input end of a gamma detector 6 installed inside a first shield 4. The output end of the gamma detector 6 is connected to the input end of a beta detector 9 installed inside a second shield 8. The output end of the beta detector 9 is connected to the input end of an alpha detector 10 also installed inside the second shield 8. The output end of the alpha detector 10 is connected to the water body.

[0069] A flow meter 3 and a pressure gauge 7 are optionally positioned between the gamma detector 6, beta detector 9, alpha detector 10, and the water treatment components. The flow meter 3 is used to monitor and control the flow rate of the water sample, ensuring stable flow throughout the system; the pressure gauge 7 is used to monitor the pressure of the water sample, preventing pressure fluctuations from affecting measurement accuracy.

[0070] A peristaltic pump propels liquid flow by squeezing a pipe, offering advantages such as minimal direct contact with the water sample and reduced risk of contamination. The extracted water sample passes through the peristaltic pump into particle filter 1 to remove particulate matter, and then into ultraviolet generator 2. Ultraviolet light is emitted to disinfect and kill algae, further ensuring the cleanliness of the water sample and preventing biological contamination from interfering with subsequent measurements. Typically, the flow rate of the peristaltic pump is 10 L / min.

[0071] In addition, the system also includes a water sample retention component. The output of the α detector 10 is connected to the water sample retention component and the water body respectively through a three-way pipe. A switch valve is installed at the inlet of the water sample retention component.

[0072] By retaining a portion of the water sample for subsequent laboratory analysis or quality control, and because the water sample retention component is directly connected to the α detector 10, the retained water sample can fully represent the sample characteristics measured during the detection process, ensuring the accuracy and consistency of subsequent analyses.

[0073] Example 2

[0074] like Figure 1 and Figure 2 As shown, the first shield 4 has a cavity inside, and a shield water tank 5 is installed inside the cavity. The γ detector 6 is installed inside the shield water tank 5. Both the first shield 4 and the shield water tank 5 are provided with a water inlet and a water outlet that connect the inlet and outlet of the γ detector 6. The water inlet is connected to the output end of the water treatment component, and the water outlet is connected to the input end of the β detector 9.

[0075] The gamma detector 6 includes a main detector and an anti-coincidence detector. The main detector is provided with a central waterway connecting the waterway inlet and the waterway outlet. The anti-coincidence detectors are arranged in a ring, and the main detector is located inside the anti-coincidence detectors.

[0076] The main detector consists of a large-volume NaI detector and a main photomultiplier tube, with the main photomultiplier tube coupled to the large-volume NaI detector.

[0077] The anti-coincidence detector includes a NaI ring crystal array 61 and a first photomultiplier tube 62, with multiple first photomultiplier tubes 62 coupled to multiple scintillation crystals in the NaI ring crystal array 61.

[0078] The nuclear decay signals recorded in the detector include pulse signals from the sample and background signals from the environment. The background mainly comes from three sources: surrounding radionuclides, cosmic rays, and electronic noise.

[0079] To reduce background noise, a combination of physical shielding and anti-coincidence techniques is employed. A portion of the ambient gamma rays is shielded by the first shielding body 4 and the shielding water tank 5, thus shielding surrounding radionuclides and external background light signals. This minimizes the background noise of the measurement chamber and improves the collection efficiency of the fluorescence signal. Some gamma rays pass through the main detector and deposit energy in the anti-coincidence detector. An anti-coincidence algorithm is used to subtract this portion of gamma rays, achieving the goal of reducing background noise.

[0080] The main detector directly measures gamma rays in the water sample. It consists of a large-volume NaI (sodium iodide) detector and a main photomultiplier tube coupled to it. The NaI detector converts gamma rays into optical signals through the scintillation effect, while the main photomultiplier tube further amplifies these optical signals and converts them into detectable electrical signals, thereby achieving accurate measurement of gamma rays.

[0081] The anti-coincidence detector is arranged in a ring around the main detector and is mainly used to eliminate interference from ambient gamma rays on the measurement. It consists of a NaI ring crystal array 61 and multiple first photomultiplier tubes 62. These photomultiplier tubes are coupled to scintillation crystals in the NaI ring crystal array 61. When ambient gamma rays pass through the main detector and enter the anti-coincidence detector, the anti-coincidence detector captures these rays and excludes them from the measurement data through an anti-coincidence algorithm, thereby significantly reducing the measurement background noise and improving the measurement accuracy of the detector.

[0082] Example 3

[0083] Alpha and beta rays have short ranges, so the detector needs to be placed in the water sample to achieve online measurement. To adapt to different water environments, the selected scintillation crystal needs to be non-hygroscopic and corrosion-resistant. At the same time, the main detector needs to have the ability to distinguish between alpha and beta rays and have good energy resolution.

[0084] like Figure 1 and Figure 3 As shown, the second shield 8 has a β placement cavity inside, and the β detector 9 is placed inside the β placement cavity;

[0085] The β detector 9 includes: a plastic scintillator plate 91 and a second photomultiplier tube 92. The two plastic scintillator plates 91 are arranged in parallel, and the inner sides of the two plastic scintillator plates 91 form a β measurement chamber. The input end of the β measurement chamber passes through the β placement cavity and is connected to the output end of the γ detector 6. The output end of the β measurement chamber passes through the β placement cavity and is connected to the input end of the α detector 10.

[0086] Multiple second photomultiplier tubes 92 are respectively disposed on the outer side of the plastic scintillator plate 91. The photomultiplier tubes in this embodiment are silicon photomultiplier tubes (SiPM).

[0087] The β measurement chamber is sealed on all sides, and the surface of the plastic scintillator plate 91 is covered with a PMMA protective film.

[0088] The β detector 9 consists of two parallel plastic scintillator plates 91 and multiple second photomultiplier tubes 92. A β measurement chamber is formed between the two plastic scintillator plates 91 for measuring the β radioactivity activity of the water sample. The surface of the plastic scintillator plates 91 is covered with a PMMA protective film. This protective film primarily serves to prevent corrosion of the scintillator plates by chemicals in the water sample, extend the detector's lifespan, and ensure the stability and accuracy of the measurement.

[0089] When the water sample flows through the β measurement chamber, β particles interact with the plastic scintillator, generating photon signals. These photon signals are collected and amplified by multiple second photomultiplier tubes 92 located outside the plastic scintillator plate 91, and finally converted into electrical signals for subsequent analysis.

[0090] Example 4

[0091] The second shield 8 has an α placement cavity inside, and the α detector 10 is placed inside the α placement cavity.

[0092] Because alpha particles have a short range and lose energy quickly in matter, the alpha detector 10 includes: a particle scintillator, a light guide support 101, and a third photomultiplier tube 102. The interior of the light guide support 101 is an alpha measurement chamber, in which multiple particle scintillators are distributed. The input end of the alpha measurement chamber extends out of the alpha placement cavity and connects to the output end of the beta detector 9. The output end of the alpha measurement chamber extends out of the alpha placement cavity and connects to the water body.

[0093] Multiple third photomultiplier tubes 102 are respectively disposed on the outside of the light guide support 101.

[0094] An alpha measurement chamber is formed inside the light guide support 101, and multiple micro-scintillators are uniformly distributed within the alpha measurement chamber. A micro-scintillator is a material capable of interacting with alpha particles; when an alpha particle passes through it, the scintillator emits a light signal. These light signals pass through the light-transmitting light guide support 101 and are received by a third photomultiplier tube 102, which converts these signals into electrical signals.

[0095] Microparticle scintillators are scintillating materials composed of tiny particles, used to detect high-energy particles such as alpha particles, and have high sensitivity and response speed.

[0096] The light guide support 101 is usually made of optical fiber or other high light transmittance materials to ensure that the light signal can be effectively transmitted to the photomultiplier tube.

[0097] Example 5

[0098] Provide a specific example.

[0099] The detector parameters are as follows:

[0100] Beta detector: consists of two plastic scintillator plates, each measuring 500mm*500mm*0.3mm, and is used with a high-performance silicon photomultiplier tube (SiPM).

[0101] Alpha detector: a microparticle scintillator (filled in a 20mm thick measurement chamber), used in conjunction with a high-performance silicon photomultiplier tube (SiPM);

[0102] γ detector: 6 sets of NaI scintillators (φ25mm H40mm) ring crystals and photomultiplier tube arrays.

[0103] The radiation detection performance is as follows:

[0104] Background count pass rate: ≥250kcps;

[0105] Energy resolution and energy range: The NaI gamma online spectrometer has an energy resolution better than 4% (662 keV for Cs-137), and measures gamma rays with energies from 200 keV to 3 MeV. Depending on the detection site, the following nuclides can be selected for monitoring: Co-58, Co-60, Mn-54, Sb-124, Cs-137, I-131, Bi-214, Tl-208, K-40, etc.

[0106] Track ratio: α to β: less than 10%; β to α: less than 2%;

[0107] Minimum detectable activity concentration (MDAC) detection limit: (12 hours)

[0108] γ: less than 0.2 Bq / L 137Cs;

[0109] α: less than 0.05 Bq / L;

[0110] β: less than 0.5 Bq / L;

[0111] Response speed: alarm within 15 minutes, total α alarm limit is 0.5 Bq / L; total β alarm limit is 1 Bq / L;

[0112] Electrical characteristics: Main power supply is 220V (±10%), 50 / 60Hz; backup power supply is an online UPS with a power supply time of not less than 0.5h;

[0113] Environmental adaptability: Operating temperature: -0℃~+50℃; Storage temperature: -10℃~+60℃; Humidity: 10%-95%.

[0114] Mechanical characteristics: Total weight: excluding test water sample: ≤500kg; External dimensions (length × width × height): ≤(1300±5)mm×(800±5)mm×(1200±5)mm.

[0115] The system is installed on the inlet pipe and continuously monitors the total radioactivity and nuclides in the drainage of the entire facility 24 hours a day. The detector is designed to be easily replaceable.

[0116] Example 6

[0117] like Figure 7 As shown, the online measurement system for total radioactivity and nuclides in water, as described in this invention, achieves efficient identification of multiple nuclides and accurate measurement of radioactivity activity in water through a series of advanced algorithms and hardware designs. Key steps in system operation include initial value verification calculation, structural characterization correction, sampling via composite measurement channels, energy-resolved counting statistics, energy spectrum deconvolution, and multi-nuclide identification.

[0118] Initial value verification calculations and structural characterization corrections are fundamental steps in the system, used to correct and verify the detector's initial parameters and structural characteristics to ensure the accuracy of subsequent measurements.

[0119] During the sampling process, the system employed a composite measurement channel sampling method, comprehensively capturing radiation information from water samples through multi-probe measurements. Subsequently, the system performed energy-resolution counting and statistics, utilizing an FPGA-based interval multi-pulse clustering algorithm and an energy spectrum deconvolution algorithm. These algorithms, through meticulous analysis and processing of the measurement signals, significantly improved energy resolution, reduced measurement errors, and ensured accurate identification of different rays (α, β, γ).

[0120] The interval multi-pulse clustering algorithm consists of an interval seed averaging algorithm and a digital doubling technique. The interval seed averaging algorithm implements a selective method for performing statistical analysis within a narrow pulse amplitude window. When measuring the height of the first pulse, it creates a statistical range based on the statistical window. When measuring the amplitude of the second pulse within this statistical range, the two pulse amplitudes are averaged, and the center of the statistical range is moved to the calculated average. This process continues until a predetermined number of statistical pulse amplitudes are reached, at which point the average pulse amplitude is extracted as the pulse amplitude.

[0121] Certain energies of α and β rays in water can cause detectors to record repeatedly, thus requiring α and β differentiation. Research into multi-probe measurement algorithms can enable accurate measurement of total α and β activity concentrations. Based on the different decay times of α, β, and γ rays in a scintillation crystal, resulting in different pulse shapes and amplitudes, pulse discrimination techniques are used to differentiate between the two types of pulses. α, β, and γ pulses are acquired using an oscilloscope, and the effectiveness of different discrimination algorithms is calculated in MATLAB. The optimal algorithm is then implemented on an FPGA to determine the decay of different types of rays.

[0122] Radiation rays of similar energies also exhibit peak overlap, forming complex energy spectra. Therefore, research is needed on the identification and analysis techniques for multiple nuclides in gamma spectroscopy. This study investigates information extraction and recognition techniques using artificial neural networks, applying these networks to the rapid identification and processing of nuclides. Combined with spectral analysis methods, this enables rapid identification and analysis of multiple nuclides based on a NaI gamma spectrometer.

[0123] Finally, the system performs automated multi-nucleoside total activity analysis on all measurement data, and automatically generates a report on the radioactivity concentration of the water body by combining various measurement parameters. Simultaneously, the system has early warning-alarm and online recording remote monitoring functions, which can automatically issue alarms when the radioactivity of the water body exceeds the standard, and supports remote data access and real-time monitoring.

[0124] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0125] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0126] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above invention, and these changes or modifications still fall within the scope of the present invention.

Claims

1. An online measurement system for total radioactivity and nuclides in water, characterized in that, include: The water treatment component includes a gamma detector (6), a beta detector (9), an alpha detector (10), and a water treatment assembly. The water treatment assembly extracts and processes water samples, which are then passed through the gamma detector (6), beta detector (9), and alpha detector (10). The gamma detector (6) is located inside a first shield (4), and the beta detector (9) and the alpha detector (10) are located inside a second shield (8). The γ detector (6) acquires the γ energy spectrum of the water sample, the β detector (9) acquires the β total activity of the horizontal sample, and the α detector (10) acquires the α total activity of the horizontal sample. The first shield (4) has a cavity inside, and a shield water tank (5) is installed inside the cavity. The γ detector (6) is installed inside the shield water tank (5). Both the first shield (4) and the shield water tank (5) are provided with a water inlet and a water outlet that connect to the inlet and outlet of the γ detector (6). The water inlet is connected to the output end of the water treatment component, and the water outlet is connected to the input end of the β detector (9). The second shield (8) has a β placement cavity inside, and the β detector (9) is installed inside the β placement cavity. The β detector (9) includes: a plastic scintillator plate (91) and a second photomultiplier tube (92). The two plastic scintillator plates (91) are arranged in parallel, and the inner sides of the two plastic scintillator plates (91) are connected to a β measurement chamber. The input end of the β measurement chamber passes through the β placement cavity and is connected to the output end of the γ detector (6). The output end of the β measurement chamber passes through the β placement cavity and is connected to the input end of the α detector (10). A plurality of second photomultiplier tubes (92) are respectively arranged on the outside of the plastic scintillator plate (91). An α placement cavity is provided inside the second shield (8), and the α detector (10) is arranged inside the α placement cavity. The α detector (10) includes: a particle scintillator, a light guide support (101), and a third photomultiplier tube (102). The interior of the light guide support (101) is an α measurement chamber, and multiple particle scintillators are distributed in the α measurement chamber. The input end of the α measurement chamber extends out of the α placement cavity and is connected to the output end of the β detector (9). The output end of the α measurement chamber extends out of the α placement cavity and is connected to the water body. Multiple third photomultiplier tubes (102) are respectively disposed on the outside of the light guide support (101).

2. The online measurement system for total radioactivity and nuclides in water according to claim 1, characterized in that, The water treatment assembly includes a peristaltic pump, a particle filter (1), and an ultraviolet generator (2). The input end of the peristaltic pump is connected to the water body, the output end of the peristaltic pump is connected to the input end of the particle filter (1), the output end of the particle filter is connected to the input end of the ultraviolet generator (2), the output end of the ultraviolet generator (2) is connected to the input end of the γ detector (6) disposed in the first shield (4), the output end of the γ detector (6) is connected to the input end of the β detector (9) disposed in the second shield (8), the output end of the β detector (9) is connected to the input end of the α detector (10) disposed in the second shield (8), and the output end of the α detector (10) is connected to the water body.

3. The online measurement system for total radioactivity and nuclides in water according to claim 1, characterized in that, A flow meter (3) and a pressure gauge (7) are optionally located between the γ detector (6), the β detector (9), the α detector (10), and the water treatment assembly.

4. The online measurement system for total radioactivity and nuclides in water according to claim 1, characterized in that, The gamma detector (6) includes a main detector and an anti-coincidence detector. The main detector is provided with a central waterway connecting the waterway inlet and the waterway outlet. The anti-coincidence detectors are arranged in a ring, and the main detector is located inside the anti-coincidence detector. The main detector is a large-volume NaI detector and a main photomultiplier tube, and the main photomultiplier tube is coupled to the large-volume NaI detector; The anti-coincidence detector includes a NaI ring crystal array (61) and a first photomultiplier tube (62), wherein a plurality of the first photomultiplier tubes (62) are coupled to a plurality of scintillation crystals in the NaI ring crystal array (61).

5. The online measurement system for total radioactivity and nuclides in water according to claim 1, characterized in that, The β measuring chamber is sealed on all sides, and the surface of the plastic scintillator plate (91) is covered with a PMMA protective film.

6. The online measurement system for total radioactivity and nuclides in water according to claim 2, characterized in that, It also includes a water sample retention component. The output end of the α detector (10) is connected to the water sample retention component and the water body respectively through a three-way pipe. A switch valve is provided at the inlet of the water sample retention component.

7. The online measurement system for total radioactivity and nuclides in water according to claim 2, characterized in that, The flow rate of the peristaltic pump is 10 L / min.

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