阅读说明：本技术 一种饮用水中放射性在线测量装置和测量方法 (On-line measuring device and method for radioactivity in drinking water ) 是由 覃国秀 潘靓亮 李凡 关百尧 于 2021-05-26 设计创作，主要内容包括：本发明公开一种饮用水中放射性核素在线测量方法,包括：水样采集、放射性测量和数据处理三个部分。水样采集部分能够将饮用水连续不断的采集到测量室；放射性测量部分能够快速准确地测量饮用水中的α、β和γ放射性核素污染物；数据处理部分用于对获取的核信号进行实时处理,选择感兴趣的信号幅度谱进行分析,当信号的计数率超过阈值或计数率随时间变化超过一定程度则自动报警。本在线测量方法解决了水系统的常规监测方法无法检测短期污染、无法连续监测水系统放射性污染、无法直接判断饮用水是否受到污染的问题。本发明还提出一种饮用水中放射性在线测量装置。(The invention discloses an online measuring method of radioactive nuclide in drinking water, which comprises the following steps: water sample collection, radioactivity measurement and data processing. The water sample collecting part can continuously collect the drinking water to the measuring chamber; the radioactivity measuring part can quickly and accurately measure alpha, beta and gamma radionuclide pollutants in the drinking water; the data processing part is used for processing the acquired nuclear signals in real time, selecting the interesting signal amplitude spectrum for analysis, and automatically giving an alarm when the counting rate of the signals exceeds a threshold value or the counting rate changes along with time to exceed a certain degree. The online measurement method solves the problems that the conventional monitoring method of the water system can not detect short-term pollution, can not continuously monitor the radioactive pollution of the water system and can not directly judge whether the drinking water is polluted or not. The invention also provides an on-line measuring device for radioactivity in drinking water.)

1. The utility model provides an online measuring device of radioactivity in drinking water which characterized in that: the measuring chamber is cylindrical, an aluminum foil is adhered to the inner wall of the measuring chamber, a light-transmitting plate made of glass covers the top of the measuring chamber, the measuring chamber is further provided with a water inlet used for inputting drinking water and a water outlet used for discharging the drinking water, the detector is made of a plastic scintillator, the detector comprises an outer ring and an inner ring group, the outer ring is cylindrical and divides the inside of the measuring chamber into two independent chambers, the inner ring group consists of a plurality of nested annular bodies, a drinking water flowing channel is formed between every two adjacent annular bodies, overflow holes are formed in the top of the measuring chamber, the lower ends of the channels between the annular bodies are communicated with the water inlet, and the upper ends of the overflow holes are communicated with the water outlet through the chambers between the outer ring and the measuring chamber; the top of the measuring chamber is provided with an inverted funnel-shaped light guide, the lower end of the light guide is buckled at the top of the measuring chamber, the upper end of the light guide is provided with a photomultiplier, and the photomultiplier is in signal connection with the data processing device.

2. An on-line measuring method of radioactivity in drinking water, using the on-line measuring device of radioactivity in drinking water of claim 1, characterized in that: the drinking water is input into the measuring chamber through the water inlet by the peristaltic pump, the drinking water flows through the detector, alpha and beta particles emitted by radionuclide decay in the drinking water interact with the detector to generate fluorescence, one part of the fluorescence directly passes through glass at the top of the measuring chamber to enter the light guide, the other part of the fluorescence is reflected by aluminum foil on the inner wall of the measuring chamber to enter the light guide, the fluorescence is transmitted to the photomultiplier by the light guide and converted into photoelectrons at the photocathode, and the photoelectrons are multiplied by the photomultiplier to finally obtain nuclear signals which can be processed by the data processing device.

3. The method for on-line measurement of radioactivity in drinking water according to claim 2, wherein: the data processing device processes the nuclear signals in the following mode:

step 1, signal discrimination: performing signal selection on the nuclear signals to reduce the interference of noise on counting and selecting proper signal amplitude for screening;

step 2, filtering and shaping: filtering and shaping the nuclear signals screened in the step 1 to form quasi-Gaussian waveforms so as to improve the signal-to-noise ratio of the system;

step 3, counting and displaying: and (3) finishing classification counting of the nuclear signals after filtering and shaping in the step 2 in a counting display module to obtain a pulse amplitude spectrum.

4. The method for on-line measurement of radioactivity in drinking water according to claim 3, wherein: in step 2, a quasi-gaussian filter forming circuit is used for carrying out filter forming processing on the kernel signal, the input signal obtained in step 1 is firstly subjected to signal width narrowing through a one-time zero-cancellation circuit, then is subjected to forming through a three-time integration circuit to form a quasi-gaussian waveform, and a filter formed by the zero-cancellation circuit and the integration circuit is a band-pass filter.

5. The method for on-line measurement of radioactivity in drinking water according to claim 3, wherein: in step 3, classifying and counting the input signals by using a multichannel pulse amplitude analyzer to obtain a pulse amplitude distribution spectrum; then, the interested pulse amplitude is selected for analysis to obtain the activity concentration of the corresponding radionuclide, and when the activity concentration value is found to exceed the limit value, an automatic alarm is given.

Technical Field

The invention relates to the field of radionuclide measurement, in particular to an online measuring device and a measuring method for radioactivity in drinking water.

Background

The ingestion of radionuclides is one of the ways in which the human body is exposed to radiation, and the ingestion of large quantities of radionuclides increases the risk of cancer, and therefore ensuring a safe water supply is of great importance to public health. Drinking water systems are susceptible to contamination by radioactive substances due to accidents or human accidents. Conventional monitoring methods for water systems (periodic sampling for laboratory analysis) do not detect short-term contamination and therefore do not protect people from radiation exposure. In order to monitor the radioactive contamination of water systems caused by nuclear accidents, on-site on-line measurements are required to quickly and accurately assess alpha, beta and gamma radionuclide contaminants. However, there is currently no complete on-line monitoring method to permanently monitor drinking water systems.

Disclosure of Invention

In order to solve the problems, the invention provides an online radioactive measuring device for drinking water, which can be used for online measuring whether the content of radioactive nuclide pollutants in tap water exceeds the standard or not. The invention also provides an online measuring method for radioactivity in drinking water.

In order to achieve the purpose, the invention adopts the technical scheme that:

in the first technical scheme, the device for measuring the radioactivity in the drinking water on line comprises a measuring chamber, a detector, a light guide, a photomultiplier and a data processing device, wherein the measuring chamber is in a barrel shape, an aluminum foil is adhered on the inner wall of the measuring chamber, a light-transmitting plate made of glass covers the top of the measuring chamber, the measuring chamber is also provided with a water inlet for inputting drinking water and a water outlet for discharging lead water, the detector is made of a plastic scintillator and comprises an outer ring and an inner ring group, wherein the outer ring is cylindrical, the outer ring divides the interior of the measuring chamber into two independent chambers, the inner ring group consists of a plurality of nested annular bodies, a channel for flowing drinking water is formed between two adjacent annular bodies, the top of the measuring chamber is provided with overflow holes, the lower end of the channel between the annular bodies is communicated with the water inlet, and the upper end of the overflow hole is communicated with the water outlet through a cavity between the outer ring and the measuring chamber; the top of the measuring chamber is provided with an inverted funnel-shaped light guide, the lower end of the light guide is buckled at the top of the measuring chamber, the upper end of the light guide is provided with a photomultiplier, and the photomultiplier is in signal connection with the data processing device.

In a second technical scheme, the method for measuring the radioactivity in the drinking water on line is characterized in that the device for measuring the radioactivity in the drinking water on line in the first technical scheme is used, the drinking water is input into a measuring chamber from a water inlet through a peristaltic pump, the drinking water flows through a detector, alpha and beta particles emitted by radionuclide decay in the drinking water interact with the detector to generate fluorescence, a part of the fluorescence directly passes through glass at the top of the measuring chamber to enter a light guide, the other part of the fluorescence is reflected by aluminum foil on the inner wall of the measuring chamber to enter the light guide, the fluorescence is transmitted to a photomultiplier through the light guide and is converted into photoelectrons at a photocathode, and the photoelectrons are multiplied by the photomultiplier to finally obtain a nuclear signal which can be processed by a data processing device.

In the second technical means, the data processing apparatus preferably processes the core signal in the following manner:

step 1, signal discrimination: performing signal selection on the nuclear signals to reduce the interference of noise on counting and selecting proper signal amplitude for screening;

step 2, filtering and shaping: filtering and shaping the nuclear signals screened in the step 1 to form quasi-Gaussian waveforms so as to improve the signal-to-noise ratio of the system;

step 3, counting and displaying: and (3) finishing classification counting of the nuclear signals after filtering and shaping in the step 2 in a counting display module to obtain a pulse amplitude spectrum.

In the second technical solution, preferably, in step 2, a quasi-gaussian filter shaping circuit is used to perform filter shaping processing on the kernel signal, the input signal obtained in step 1 is first subjected to a one-time zero-crossing cancellation circuit to narrow the signal width, and then subjected to a three-time integration circuit to form a quasi-gaussian waveform, and a filter formed by the zero-crossing cancellation circuit and the integration circuit is a band-pass filter.

In the second technical solution, preferably, in step 3, a multichannel pulse amplitude analyzer is used to perform classification counting on the input signals to obtain a pulse amplitude distribution spectrum; then, the interested pulse amplitude is selected for analysis to obtain the activity concentration of the corresponding radionuclide, and when the activity concentration value is found to exceed the limit value, an automatic alarm is given.

The beneficial effects of the invention are as follows:

the problems that the conventional monitoring method (sampling periodically for laboratory analysis) of the water system can not detect short-term pollution, can not continuously monitor the radioactive pollution of the water system, and can not directly judge whether the drinking water is polluted or not are solved.

The designed water sample collecting part based on the automatic sampling principle sends drinking water into the measuring chamber through the peristaltic pump, the collected water sample is continuously monitored in the measuring chamber, and the monitoring result is displayed in real time through the counting display part, so that the defect that the conventional monitoring method cannot continuously monitor the radioactive pollution of a water system is overcome;

designed radioactivity measuring part based on plastic scintillator, which uses very thin and close plastic scintillator to measure alpha and low-energy beta rays emitted by radionuclide decay

The designed data display part realizes the filtering forming, the classification counting, the activity conversion and the over-threshold alarm of the nuclear signal and overcomes the defect that the conventional monitoring method can not directly judge whether the drinking water is polluted or not.

Drawings

Fig. 1 is a schematic diagram of the device for measuring radioactivity in drinking water on line.

FIG. 2 is a schematic view of a measuring chamber of the device for on-line measuring radioactivity in drinking water of the present invention.

Fig. 3 is a schematic side view of a detector in the online measuring device for radioactivity in drinking water.

Fig. 4 is a schematic top view of a detector in the online measuring device for radioactivity in drinking water.

FIG. 5 is a schematic view of the radioactivity measuring process in the online measuring device for radioactivity in drinking water according to the present invention.

FIG. 6 is a schematic diagram of nuclear signal processing in the online radioactivity measuring device in drinking water according to the present invention.

The reference numerals include:

1-drinking water supply system, 2-peristaltic pump, 3-measuring chamber, 31-light-transmitting plate, 32-water inlet, 33-water outlet, 4-detector, 41-outer ring, 42-inner ring group, 43-overflow hole, 5-light guide, 6-photomultiplier and 7-data processing device.

Detailed Description

In order to make the purpose, technical solution and advantages of the present technical solution more clear, the present technical solution is further described in detail below with reference to specific embodiments. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present teachings.

Example 1

As shown in fig. 1-6, the present embodiment provides an online measuring device for radioactivity in drinking water, which includes a measuring chamber 3, a detector 4, a light guide 5, a photomultiplier 6 and a data processing device 7, wherein the measuring chamber 3 is in a cylindrical shape, an aluminum foil is adhered to an inner wall of the measuring chamber 3, a transparent plate 31 made of glass is covered on a top of the measuring chamber 3, the measuring chamber 3 further has a water inlet 32 for inputting drinking water and a water outlet 33 for discharging drinking water, the detector 4 is made of a plastic scintillator, the detector 4 includes an outer ring 41 and an inner ring group 42, wherein the outer ring 41 is in a cylindrical shape, the outer ring 41 divides the inside of the measuring chamber 3 into two independent chambers, the inner ring group 42 is composed of a plurality of nested annular bodies, a channel for flowing drinking water is formed between two adjacent annular bodies, an overflow hole 43 is formed on the top of the measuring chamber 3, and a lower end of the channel between the annular bodies is communicated with the water inlet 32, the upper end of the overflow hole 43 communicates with the water outlet 33 through the chamber between the outer ring 41 and the measuring chamber 3; the top of the measuring chamber 3 is provided with an inverted funnel-shaped light guide 5, the lower end of the light guide 5 is buckled on the top of the measuring chamber 3, the upper end of the light guide 5 is provided with a photomultiplier 6, and the photomultiplier 6 is in signal connection with a data processing device 7.

Example 2

An online measurement method for radioactivity in drinking water comprises the steps that the online measurement device for radioactivity in drinking water in embodiment 1 is used, drinking water is input into a measurement chamber 3 through a water inlet 32 through a peristaltic pump 2, the drinking water flows through a detector 4, alpha and beta particles emitted by radionuclide decay in the drinking water interact with the detector 4 to generate fluorescence, a part of the fluorescence directly penetrates through glass on the top of the measurement chamber 3 to enter a light guide 5, the other part of the fluorescence is reflected by aluminum foil on the inner wall of the measurement chamber 3 to enter the light guide 5, the fluorescence is transmitted to a photomultiplier 6 through the light guide 5 and is converted into photoelectrons at a photocathode, and the photoelectrons are multiplied by the photomultiplier 6 to finally obtain nuclear signals capable of being processed by a data processing device 7.

The data processing device 7 processes the core signal as follows:

step 1, signal discrimination: performing signal selection on the nuclear signals to reduce the interference of noise on counting and selecting proper signal amplitude for screening;

step 2, filtering and shaping: filtering and shaping the nuclear signals screened in the step 1 to form quasi-Gaussian waveforms so as to improve the signal-to-noise ratio of the system;

step 3, counting and displaying: and (3) finishing classification counting of the nuclear signals after filtering and shaping in the step 2 in a counting display module to obtain a pulse amplitude spectrum.

In step 2, a quasi-gaussian filter forming circuit is used for carrying out filter forming processing on the kernel signal, the input signal obtained in step 1 is firstly subjected to signal width narrowing through a one-time zero-cancellation circuit, then is subjected to forming through a three-time integration circuit to form a quasi-gaussian waveform, and a filter formed by the zero-cancellation circuit and the integration circuit is a band-pass filter.

In step 3, classifying and counting the input signals by using a multichannel pulse amplitude analyzer to obtain a pulse amplitude distribution spectrum; then, the interested pulse amplitude is selected for analysis to obtain the activity concentration of the corresponding radionuclide, and when the activity concentration value is found to exceed the limit value, an automatic alarm is given.

Example 3

Example 3 the specific procedure and effects of the present measuring apparatus and measuring method will be described in detail with reference to example 1 and example 2.

Water sample collection: the water sample collecting part is provided with a drinking water supply system 1 and a measuring chamber 3, so that the online collection and discharge of drinking water are realized. The sampling pipeline mainly completes the collection function of the drinking water, the realization principle is as shown in figure 2, one water pipe is connected to a drinking water supply system 1, and the drinking water is collected to a measuring chamber 3 through a peristaltic pump 2. The top of the measuring chamber 3 is a glass light-transmitting plate 31, the other parts are made of ABS plastic, a layer of aluminum foil is adhered to the inner wall (the top is light-transmitting) of the measuring chamber 3, so that the interference of the outside to the detector 4 and the photomultiplier tube 6 can be isolated, and simultaneously, the fluorescence generated by the action of rays and the detector 4 is reflected to the photomultiplier tube 6.

And (3) radioactivity measurement: the detector 4 is designed in the part, and the measurement of radioactivity in drinking water is realized. The detector 4 mainly completes the detection function of nuclear radiation in drinking water, and is designed into a mode of nesting circular columns in order to detect the radioactivity in the drinking water in real time, wherein the outer ring 41 of the outermost detector 4 divides the measuring chamber 3 into an inner part and an outer part, the detector 4 has the structure shown in fig. 3 and 4, drinking water enters from a water inlet at the bottom of the detector 4, the tops of the outer ring 41 and the inner ring 42 are provided with overflow holes 43 with the diameter of 5mm, and when the pumped drinking water exceeds the overflow holes 43, the drinking water enters the measuring chamber 3 at the periphery of the outer ring 41 through the overflow holes 43 and then flows out of the measuring chamber 3 through the water outlet 33. If radionuclides are contained in the drinking water, the alpha and beta particles emitted by the decay of these radionuclides interact with the detector 4 to produce fluorescence. Some of this fluorescence light passes directly through the glass at the top of the measurement chamber 3 into the light guide 5, and some other fluorescence light is reflected by the aluminum foil on the inner wall of the measurement chamber 3 and enters the light guide 5 for the most part, as shown in fig. 5. The fluorescence is transmitted through the light guide 5 to the photomultiplier 6, converted at the photocathode into photoelectrons, which are multiplied at the photomultiplier 6, and finally, nuclear signals that can be processed by the data processing device 7 are obtained.

The light guide 5 of the radioactivity measuring part transmits the fluorescence output by the plastic scintillator detector 4 to the photocathode of the photomultiplier tube 6, where the light guide 5 has two functions: firstly, the measuring chamber 3 is matched with the photomultiplier 6, secondly, the fluorescence generated by the detector 4 is collected as much as possible, the more the collected fluorescence is, the more useful information is, and thus, the voltage of the photomultiplier 6 can be reduced, thereby reducing the noise. The photomultiplier 6 of the radioactivity measuring part converts the fluorescence transmitted from the light guide 5 into photoelectrons, and amplifies the electric signals to finally obtain appropriate signals which can be processed by the data processing device 7.

Data processing: the data processing part is designed with signal discrimination, filtering shaping and counting display, and is mainly used for processing nuclear signals output by the detector 4 and displaying results. As shown in fig. 6, the nuclear signal is first screened by signal screening; then, the nuclear signal is shaped into a quasi-Gaussian waveform and the interference of noise is reduced in a filtering and shaping module; and the nuclear signals after the filter shaping is finished are classified and counted in a counting display module and the result is displayed.

The foregoing is only a preferred embodiment of the present invention, and many variations in the specific embodiments and applications of the invention may be made by those skilled in the art without departing from the spirit of the invention, which falls within the scope of the claims of this patent.