Radioactivity measurement device for waste classification

Abstract

The invention relates to the technical field of radioactivity measurement, in particular to a radioactivity measurement device for waste classification, which comprises a control module for controlling the opening and closing of the radioactivity measurement device, the control module further comprises an analysis module and a general control data analysis module; and the detection module is composed of a cubic measurement cabin and a Na I detector array. According to the invention, by arranging components such as a control module, a detection module, a signal processing unit, a single-path analysis module, a general control data analysis module and an adjustment module, through a cooperation relationship between 96 NaI detector arrays uniformly distributed on six surfaces in the detection module and a spatial discrete model of the general control data analysis module, the detection module can be used for detecting the spatial discrete model of the general control data analysis module; the total control data analysis module can calculate and analyze the radionuclide and the total activity of the detected object based on the detection efficiency database of 64 areas, so that the device can detect the radioactive waste in a multi-angle and non-blind area manner.

Description

Technical Field

[0001] This invention relates to the field of radioactivity measurement technology, and more specifically to a radioactivity measurement device for waste sorting. Background Technology

[0002] In nuclear power plant operation and radioactivity-related fields, the classification and treatment of low-level and extremely low-level radioactive waste is a crucial step, which is of great significance for the safe disposal of waste and the rational utilization of resources. Radioactive measuring devices detect the radioactivity of waste through modules such as detection sensors and data processing algorithms.

[0003] Traditional radioactive waste detection devices often employ single-sided or limited double-sided detector layouts. Due to space limitations, these devices have large blind spots at multiple angles of the waste, making it difficult to effectively capture gamma-ray signals from these directions. When processing non-uniform radioactive waste, there may be areas with high local radioactivity within the waste. However, due to the dilution effect of the surrounding low-activity matrix, these high-risk points are easily masked. Detection equipment often calculates results based on the overall average radioactivity level. This measurement method can result in detection values ​​that are significantly lower than the actual maximum local risk level in the waste, easily leading to misjudgments of radioactive risk. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a radioactive measurement device for waste sorting, which can effectively solve the problems of spatial detection blind spots, local radioactive risks being masked and insufficient measurement accuracy in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention provides a radioactivity measuring device for waste sorting, comprising: a control module for controlling the opening and closing of the radioactivity measuring device, the control module further comprising an analysis module and a total control data analysis module;

[0007] The detection module consists of a cubic measurement chamber and a NaI detector array;

[0008] The cube-shaped measurement chamber has an outer wall covered with a lead shield to shield the ambient gamma background, and a manual door is installed at the front.

[0009] The NaI detector array consists of 96 NaI detectors, evenly distributed on the six inner surfaces of the cubic measurement chamber, with a 4×4 array on each side. Each detector integrates a plumb collimator with an opening on its end face to form a spatially resolved detection grid. The six-sided detector array eliminates multi-angle detection blind spots.

[0010] The overall control data analysis module divides the inner cavity of the measurement chamber into 64 regions based on a spatial discrete model, calculates and analyzes the radionuclides and total activity of the tested object, and determines whether the tested object meets the clean release standard.

[0011] The signal processing unit, including a 96-channel preamplifier circuit, a pulse processing circuit, and a multi-channel processing board, is used to convert the analog pulse signal output by the NaI detector into digital energy spectrum data.

[0012] The signal receiving module is used to receive electrical signals fed back during the use of the equipment;

[0013] The adjustment module includes multiple sets of position sensors, which are electrically connected to the signal receiving module to detect the position of the container carrying waste.

[0014] Furthermore, in the linear equation, it is...

[0015] Q1 = P1*X1 + P2*X2 + P3*X3 + P4*X4 is formula 1.

[0016] Q2 = P1*X5 + P2*X6 + P3*X7 + P4*X8 is formula 2.

[0017] *****

[0018] Q16 = P1*X1 + P2*X5 + P3*X9 + P4*X12 is formula 16.

[0019] Furthermore, the single-channel analysis module is electrically connected to the signal receiving module. The single-channel analysis module is used to control and acquire the energy spectrum of a single NaI detector. The single-channel analysis module is also electrically connected to the signal processing unit for real-time data transmission.

[0020] Furthermore, the adjustment module also includes an angle adjustment unit, which is electrically connected to the signal receiving module and is used to adjust the angle of the NaI detector;

[0021] The adjustment module also includes a voltage adjustment unit, which is electrically connected to the signal receiving module, for adjusting the output voltage of a single NaI detector to stabilize the use of the NaI detector and adjust the power of the NaI detector.

[0022] Furthermore, the single-channel analysis module also includes a spectrum stabilization detection unit, which includes a gamma-ray sensor composed of a NaI crystal and a photomultiplier tube, and is electrically connected to the signal receiving module for detecting the energy spectrum stability of the NaI detector. The spectrum stabilization detection unit is electrically connected to a voltage regulation unit, and after detection, the voltage regulation module adjusts the voltage to stabilize the energy spectrum of the NaI detector.

[0023] Furthermore, the overall control data analysis module also includes a storage unit, a confidentiality management unit, and a report output unit. The storage unit is used to record and store the test data, the confidentiality management unit is used to set a password to protect the data, and the report output unit is used to output the test report.

[0024] Furthermore, the overall control data analysis module also includes a detection efficiency correction unit, which can individually edit the material and density of 64 regions.

[0025] Beneficial effects

[0026] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0027] I. This invention, by setting up components such as a control module, a detection module, a signal processing unit, a single-channel analysis module, a total control data analysis module, and an adjustment module, utilizes the coordination between the array of 96 NaI detectors evenly distributed on six sides in the detection module and the spatial discrete model of the total control data analysis module. This enables the total control data analysis module to calculate and analyze the radionuclides and total activity of the tested object based on a database of detection efficiency in 64 regions. Thus, this device achieves the effect of detecting radioactive waste from multiple angles without blind spots. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0029] Figure 1 This is a schematic diagram of the overall method of the present invention;

[0030] Figure 2 This is a schematic diagram of the single-layer NaI detector array of the present invention;

[0031] Figure 3 This is a schematic diagram of the internal method S200 of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The present invention will be further described below with reference to embodiments.

[0034] Example: A radioactive measuring device for waste sorting, comprising: a control module for controlling the start-up and shutdown of the radioactive measuring device, the control module further comprising an analysis module and a total control data analysis module;

[0035] The detection module consists of a cubic measurement chamber and a NaI detector array;

[0036] The cubic measurement chamber has lightweight, thin-walled side walls and is covered with a lead shield to protect against the ambient gamma background. It has a manual door at the front. Ideally, the device should be a cube with a side length not exceeding 1.2 meters, but the specific shape can be chosen based on actual conditions. The inner cavity is a 51cm square measurement chamber. The inner and outer walls of the device are made of stainless steel. Each of the six surfaces of the inner wall has a collimation hole for the NaI detector for subsequent calibration to ensure the detection accuracy of the NaI detector.

[0037] The NaI detector array consists of 96 NaI detectors, mounted on six sides and evenly distributed across the six inner surfaces of the cubic measurement chamber. Each side is arranged in a 4×4 array. Each detector integrates a lead collimator, which is designed according to the dimensions of the cubic measurement chamber, along with a supporting frame. A certain amount of lead is added to the outermost side of the cubic measurement chamber to form a lead shield, which covers the outer wall of the cubic measurement chamber to shield the ambient gamma background. The end face of the lead collimator has openings to form a spatially resolved detection grid for detecting the radioactivity of waste.

[0038] The preferred NaI detector is a 2-inch NaI detector, which integrates the NaI crystal, PMT, voltage divider, and multichannel design. Each NaI detector is installed in a plumb collimator, which has a cuboid structure with a side length of 125mm and a 65mm diameter collimation hole on the end face to install the NaI detector. It can be adjusted according to actual conditions.

[0039] In each section, refer to the appendix. Figure 2 The 16 NaI detectors divide the detection area into 16 blocks. The data of each NaI detector comes from the radioactive synthesis of 4 blocks in its detection field of view. The detection efficiency of each block is pre-calibrated and can be adjusted according to the material and density of the object being tested. It is equipped with a 50*50*50cm cubic container. The object being tested is placed in the container and then put into the cubic measurement chamber. After the door is closed, the measurement is started.

[0040] The signal processing unit, including a 96-channel preamplifier circuit, a pulse processing circuit, and a multi-channel processing board, is used to convert the analog pulse signal output by the NaI detector into digital energy spectrum data.

[0041] The signal receiving module is used to receive electrical signals fed back during the use of the equipment, and is electrically connected to each module unit as needed.

[0042] The single-channel analysis module is electrically connected to the signal receiving module. The single-channel analysis module is used to control and acquire the energy spectrum of a single NaI detector. The single-channel analysis module is also electrically connected to the signal processing unit for real-time data transmission.

[0043] The single-channel analysis module also includes a spectrum stabilization detection unit, which includes a gamma-ray sensor composed of a NaI crystal and a photomultiplier tube, and is electrically connected to the signal receiving module to detect the energy spectrum stability of the NaI detector. The spectrum stabilization detection unit is electrically connected to a voltage regulation unit. After detection, the voltage regulation module adjusts the voltage to stabilize the energy spectrum of the NaI detector.

[0044] The single-channel analysis module can connect or disconnect the NaI detector at any time, adjust the NaI detector sensitivity such as high voltage adjustment, start or stop measurement, or refresh data. It has a built-in editable nuclide database, supports fully automatic energy spectrum analysis of common radioactive substances, and has fully automatic energy spectrum analysis and peak fitting functions. It can set peak finding sensitivity and nuclide identification sensitivity, and has nuclide identification and net peak count rate output functions. By flexibly setting the identification sensitivity, it avoids missing weak signals or misjudging interference peaks. Finally, it outputs the nuclide type and accurate activity value. It also has self-calibration capability, completes energy scale to ensure accurate peak position and efficiency scale correlation activity calculation, and is equipped with automatic spectrum stabilization function to compensate for energy spectrum drift caused by environmental fluctuations in real time, ensuring long-term measurement stability.

[0045] During operation, the NaI detector is started through the single-channel analysis module. The NaI detector transmits the real-time acquired γ-ray energy spectrum data to the single-channel analysis module. The built-in stable spectrum detection unit of the single-channel analysis module automatically analyzes the results and sends a signal to the signal receiving module. Subsequently, the voltage sensor adjusts the voltage of the NaI detector to ensure the stability of the measurement data.

[0046] The overall control data analysis module divides the inner cavity of the measurement chamber into 64 regions based on the spatial discrete model, calculates and analyzes the radionuclides and total activity of the test object, and determines whether the test object meets the clean release standard. The test object is divided into 64 regions of 4*4*4. The detection efficiency of each region has been pre-calibrated and stored in the form of a database through the storage unit.

[0047] The overall control data analysis module also includes a storage unit, a confidentiality management unit, and a report output unit. The storage unit is used to record and store the detection data, the confidentiality management unit is used to set passwords to protect the data, and the report output unit is used to output the detection report. The overall control data analysis module also includes a detection efficiency correction unit, which can edit the material and density of 64 areas separately, and fine-tune the efficiency of each detection area based on the efficiency library to improve measurement accuracy.

[0048] like Figure 2 As shown, the analyte is divided into 16 detection regions by 16 NaI detectors. The energy spectrum data of each NaI detector comes from four detection regions within the field of view of its collimator. Taking a detector in the figure as an example, the detection efficiencies of the four regions in front of it, from near to far, are P1, P2, P3, and P4, respectively. The detector analyzes the nuclide results and obtains the net count rate of the full-energy peak as Q1. Assuming the radioactivity of the 16 regions is Xi (i = 1-16), the formula can be obtained as follows:

[0049] Q1 = P1*X1 + P2*X2 + P3*X3 + P4*X4 is formula 1.

[0050] Q2 = P1*X5 + P2*X6 + P3*X7 + P4*X8 is formula 2.

[0051] *****

[0052] Q16 = P1*X1 + P2*X5 + P3*X9 + P4*X12 is formula 16;

[0053] By analogy, 16 linear equations can be obtained, corresponding to 16 unknowns Xi. Therefore, solving the equations can yield the radioactivity Xi of 16 regions. Similarly, the radioactivity of each region in other layers can also be obtained, for a total of 64 activity values. Summing these values ​​yields the total radioactivity of the analyte.

[0054] During the calculation process, based on the actual material and density uniformity of the measured object, the overall control data analysis module can also have the detection efficiency coefficient correction function through the detection efficiency correction unit. It can edit the material and density of 64 areas separately, and fine-tune the efficiency of each detection area based on the efficiency library through existing software to improve the measurement accuracy.

[0055] The central control data analysis module preprocesses the energy spectrum data transmitted from 96 NaI detectors, discretizes the 51cm square measurement chamber into 64 cubic regions in a 4×4×4 pattern, and calls a pre-calibrated efficiency database to store detection efficiency parameters related to the density, material, and probe distance of the analyte. For the net count rate of the full-energy peak in the four regions within the field of view of each detector, such as Q1, a linear equation system is established. After solving the 16 unknown activity values ​​in the regions through matrix operations, the system expands to the 64 regions and accumulates them to obtain the total activity value. If the density of the analyte is not uniform during the calculation, the parameters of the corresponding regions can be manually edited. The system dynamically fine-tunes the detection efficiency based on the efficiency database to improve accuracy. Finally, the total activity is compared with the cleanliness and de-control standard to generate a judgment result. At the same time, the measurement data, dose rate, nuclide information, etc. are encrypted and recorded through the storage unit, and data access control is achieved through the confidentiality management unit.

[0056] The adjustment module includes multiple sets of position sensors, which are electrically connected to the signal receiving module to detect the position of the container carrying waste;

[0057] The adjustment module also includes an angle adjustment unit, which is electrically connected to the signal receiving module and is used to adjust the angle of the NaI detector.

[0058] The adjustment module also includes a voltage adjustment unit, which is electrically connected to the signal receiving module, and is used to adjust the output voltage of a single NaI detector to stabilize the use of the NaI detector and adjust the power of the NaI detector.

[0059] The position of the container carrying waste is detected by multiple sets of position sensors. If the container position shifts, an electrical signal is sent to the signal receiving module. The signal receiving module then sends the electrical signal to the angle adjustment unit to adjust the angle of the NaI detector. If the container position does not shift, no additional action is performed.

[0060] The working principle of the radioactive waste classification and measurement device provided by this invention is as follows: When the waste to be tested is placed into the container and pushed into the cubic measurement chamber, the manual door is closed and the control module is triggered to start the device. The control module then instructs each module unit to be powered on and started. The single-channel analysis module controls the start of the NaI detector and monitors the NaI detector in real time through the γ-ray sensor of the spectrum stabilization detection unit. When the NaI detector fluctuates, the γ-ray sensor sends an electrical signal to the signal receiving module. After processing, the signal receiving module sends an electrical signal to the voltage regulation unit. The voltage regulation unit adjusts the voltage of the NaI detector to maintain the energy spectrum stability.

[0061] The adjustment module starts by detecting the position of the container carrying waste using multiple position sensors. If the container position shifts, it sends an electrical signal to the signal receiving module. After processing, the signal receiving module sends the electrical signal to the angle adjustment unit. The angle adjustment unit adjusts the angle of the NaI detector. Then, based on the container's tilt angle, the voltage of the NaI detector, which is farther away from the detection container, can be adjusted by the voltage adjustment unit to increase the power of the NaI detector and ensure that the NaI detector can detect waste normally. If the container position does not shift, no additional action is performed.

[0062] Meanwhile, the lead shield in the detection module shields the ambient gamma background, and 96 NaI detectors simultaneously collect gamma-ray signals. The analog pulses output by the NaI detectors are converted into digital energy spectra by the preamplifier circuit, pulse processing circuit and multichannel processing board of the signal processing unit, and transmitted to the single-channel analysis module in real time. The single-channel analysis module has a built-in nuclide library and realizes the analysis of the energy spectrum and subtracts the cosmic ray background through nuclide identification and net peak count rate output functions.

[0063] Subsequently, the single-channel analysis module transmits the data to the central control data analysis module. After receiving the energy spectrum data, the central control data analysis module discretizes the inner cavity of the measurement chamber into 64 regions in a 4×4×4 pattern. It calls the efficiency database, which is pre-calibrated with a standard source and stores detection efficiency parameters related to material, density, and distance. A system of linear equations is established for the four regions within the field of view of each detector. After solving the 16 region activity unknowns through matrix operations, the results are extended to the 64 regions and accumulated to obtain the total activity value. If the material and density of the measured object are not uniform, the parameters of the corresponding region can be manually edited through the detection efficiency correction unit. Finally, the total activity is compared with the cleanliness control standard, and a test report is output through the report output unit. At the same time, the data is encrypted and recorded through the storage unit, and access control is achieved through the confidentiality management unit.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A radioactivity measuring device for waste sorting, characterized in that, It includes a control module for controlling the opening and closing of the radioactivity measuring device, and the control module also includes an analysis module and a master control data analysis module; The detection module consists of a cubic measurement chamber and a NaI detector array; The cube-shaped measurement chamber has an outer wall covered with a lead shield to shield the ambient gamma background, and a manual door is installed at the front. The NaI detector array consists of 96 NaI detectors, evenly distributed on the six inner surfaces of the cubic measurement chamber, with a 4×4 array on each side. Each detector integrates a plumb collimator with an opening on its end face to form a spatially resolved detection grid. The six-sided detector array eliminates multi-angle detection blind spots. The overall control data analysis module divides the inner cavity of the measurement chamber into 64 regions based on a spatial discrete model, calculates and analyzes the radionuclides and total activity of the tested object, and determines whether the tested object meets the clean release standard. The overall control data analysis module calculates and analyzes the radionuclides and total activity of the tested object through linear equations. The signal processing unit, including a 96-channel preamplifier circuit, a pulse processing circuit, and a multi-channel processing board, is used to convert the analog pulse signal output by the NaI detector into digital energy spectrum data. The signal receiving module is used to receive electrical signals fed back during the use of the equipment; The adjustment module includes multiple sets of position sensors, which are electrically connected to the signal receiving module to detect the position of the container carrying waste.

2. The radioactivity measuring device for waste sorting according to claim 1, characterized in that, The linear equation is as follows: Q1 = P1*X1 + P2*X2 + P3*X3 + P4*X4 is formula 1. Q2 = P1*X5 + P2*X6 + P3*X7 + P4*X8 is formula 2. ***** Q16 = P1*X1 + P2*X5 + P3*X9 + P4*X12 is formula 16.

3. A radioactive measuring device for waste sorting according to claim 1, characterized in that, The single-channel analysis module is electrically connected to the signal receiving module. The single-channel analysis module is used to control and acquire the energy spectrum of a single NaI detector. The single-channel analysis module is also electrically connected to the signal processing unit for real-time data transmission.

4. A radioactive measuring device for waste sorting according to claim 1, characterized in that, The adjustment module also includes an angle adjustment unit, which is electrically connected to the signal receiving module and is used to adjust the angle of the NaI detector. The adjustment module also includes a voltage adjustment unit, which is electrically connected to the signal receiving module, for adjusting the output voltage of a single NaI detector to stabilize the use of the NaI detector and adjust the power of the NaI detector.

5. A radioactive measuring device for waste sorting according to claim 3, characterized in that, The single-channel analysis module also includes a spectrum stabilization detection unit, which includes a gamma-ray sensor composed of a NaI crystal and a photomultiplier tube, and is electrically connected to the signal receiving module for detecting the energy spectrum stability of the NaI detector. The spectrum stabilization detection unit is electrically connected to a voltage regulation unit, and after detection, the voltage regulation module adjusts the voltage to stabilize the energy spectrum of the NaI detector.

6. A radioactive measuring device for waste sorting according to claim 1, characterized in that, The overall control data analysis module also includes a storage unit, a confidentiality management unit, and a report output unit. The storage unit is used to record and store the test data, the confidentiality management unit is used to set a password to protect the data, and the report output unit is used to output the test report.

7. A radioactive measuring device for waste sorting according to claim 1, characterized in that, The overall control data analysis module also includes a detection efficiency correction unit, which can individually edit the material and density of 64 regions.

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