An online gamma absorption measurement device and a post-processing online analysis system

Abstract

The present invention discloses an online measurement device for gamma absorption, comprising a detector assembly, a radioactive source assembly, a measuring cell, a calibration piece, and a data processing unit. The detector assembly and the radioactive source assembly are arranged relative to each other, the measuring cell and the calibration piece are located between the detector assembly and the radioactive source assembly, the measuring cell is used for the circulation of post-processing liquid, and the radioactive source assembly is used for emitting gamma rays to the detector assembly. The detector assembly is used for detecting the radioactivity of gamma rays passing through the measuring cell when receiving the gamma rays, so as to generate a first radioactivity signal, or, when receiving the gamma rays passing through the calibration piece, detecting the radioactivity of the gamma rays, so as to generate a second radioactivity signal. The data processing unit is connected to the detector assembly, and is used for analyzing the concentration of each metal element in the post-processing liquid when receiving the first radioactivity signal, or, when receiving the second radioactivity signal, calibrating the detector assembly. The present invention also discloses an online analysis system for post-processing.

Description

Technical Field

[0001] The invention specifically relates to a gamma absorption online measuring device and a post-processing online analysis system. Background Art

[0002] Post-processing online analysis technology is a technology that directly monitors the radioactive process logistics in the production system of the post-processing plant. It can display the instantaneous changes of the process material composition in real time. Compared with conventional sampling analysis, it has the advantages of no need for any chemical treatment, no destruction of liquid flow, continuous measurement, real-time provision of measurement results for process parameter adjustment, and remote operation. It can even replace part of the laboratory analysis to reduce the frequency of sampling and analysis, reduce the workload of personnel analysis, reduce the radiation dose of staff, and quickly and timely guide process control. Online analysis plays an irreplaceable role in improving production efficiency, controlling the loss of heavy metals and saving manpower in post-processing plants.

[0003] The gamma absorption method is a non-destructive measurement method. Its principle is to establish a linear relationship between the sample concentration and the natural logarithm of the ray intensity based on the attenuation law of gamma rays passing through the sample, and then determine the sample concentration by measuring the ray intensity. The gamma absorption method has nothing to do with the isotopic composition, valence state, chemical bonding and other states of the object to be measured, and is suitable for heavy element concentration analysis. Generally, the absorption coefficient of light elements to gamma photons is not large, while the absorption coefficient of heavy elements such as uranium, plutonium, and lead is very large. When the thickness of the absorption cell and the incident intensity of gamma rays are constant, the transmission intensity is only related to the concentration of the element to be measured. After the gamma rays pass through the uranium solution, the gamma ray intensity is weakened, so by measuring the gamma ray count rate after absorption, the concentration of the corresponding metal element can be obtained.

[0004] my country has been using on-line gamma absorption measurement devices since the production reactor period. However, previous on-line gamma absorption measurement devices had the following disadvantages: after long-term use, errors will occur in the detector components in the on-line gamma absorption measurement devices, resulting in inaccurate measurements.

[0005] Therefore, it is urgent to propose a modular γ absorption online measurement device that can be calibrated online to solve the problems that have occurred in the past, to better guide process operations, and to be more widely used in various industries. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a gamma absorption online measurement device and a post-processing online analysis system in view of the above-mentioned deficiencies in the prior art, which can facilitate the calibration of the detector assembly to improve the accuracy of the detector assembly.

[0007] According to an embodiment of the first aspect of the present invention, there is provided a γ absorption online measurement device, comprising: a measuring cell, a calibration piece, a detector assembly, a radiation source assembly and a data processing unit, wherein the detector assembly and the radiation source assembly are arranged relative to each other, the measuring cell and the calibration piece are located between the detector assembly and the radiation source assembly, the measuring cell is used for allowing post-processing liquid to flow, the radiation source assembly is used for emitting γ rays to the detector assembly, the γ rays are received by the detector assembly after passing through the measuring cell or the calibration piece, the detector assembly is used for detecting the radioactivity of the γ rays passing through the measuring cell when receiving the γ rays, so as to generate a first radioactivity signal, or, when receiving the γ rays passing through the calibration piece, detecting the radioactivity of the γ rays, so as to generate a second radioactivity signal, the data processing unit is connected to the detector assembly, and is used for analyzing the concentration of each metal element in the post-processing liquid when receiving the first radioactivity signal, or, when receiving the second radioactivity signal, calibrating the detector assembly.

[0008] Preferably, the detector assembly includes a detector, which can move between a measuring position and a calibration position, the measuring position is aligned with the measuring cell, and the calibration position is aligned with the calibration piece, the radiation source assembly is used to emit gamma rays to the measuring position and the calibration position respectively, the gamma rays emitted to the measuring position pass through the measuring cell, and the post-treatment liquid in the measuring cell can absorb the gamma rays, the gamma rays emitted to the calibration position pass through the calibration piece, and the calibration piece can absorb the gamma rays, the detector is used to detect the radioactivity of the gamma rays absorbed by the post-treatment liquid in the measuring cell when the detector is in the measuring position, and detect the radioactivity of the gamma rays absorbed by the calibration piece when the detector is in the calibration position.

[0009] Preferably, the detector assembly also includes a photomultiplier tube, and the detector is connected to the data processing unit through the photomultiplier tube. The detector is used to generate a first light signal according to the radioactivity after receiving the gamma rays absorbed by the post-processing liquid in the measuring cell, and send the first light signal to the photomultiplier tube. The photomultiplier tube is used to convert the first light signal into a first electrical signal, and amplify the first electrical signal to generate the first radioactivity activity signal, and send the first radioactivity activity signal to the data processing unit. The data processing unit is used to determine the absorption amount of the gamma rays by the post-processing liquid according to the first radioactivity activity signal, and then detect the concentration data of each metal element in the liquid, and output the concentration data of each metal element.

[0010] Preferably, the detector assembly also includes a cylinder, the telescopic end of the cylinder is connected to the detector, and is used to drive the detector to automatically move between the measurement position and the calibration position. When the detector moves to the calibration position, it is used to receive the gamma rays absorbed by the calibration piece, generate a second light signal according to its radioactive activity, and send the second light signal to the photomultiplier tube. The photomultiplier tube is also used to convert the second light signal into a second electrical signal, and amplify the second electrical signal to generate a second radioactive activity signal, and send the second radioactive activity signal to the data processing unit. The data processing unit is used to calculate the measured value of the absorption of the gamma rays by the calibration piece according to the second radioactive activity signal, and the data processing unit pre-stores the standard value of the absorption of the gamma rays by the calibration piece. The data processing unit is also used to compare the measured value with the standard value, and send a reminder signal when the difference between the measured value and the standard value is greater than the allowable range.

[0011] Preferably, the device also includes an attenuation correction unit, which is electrically connected to the data processing unit and is used to perform attenuation correction calculations on the radioactivity of the radioactive source and transmit the obtained radioactivity data of the radioactive source to the data processing unit. The data processing unit is used to calculate the absorption of gamma rays by the post-processing liquid based on the first radioactivity signal and the radioactivity data of the radioactive source, and to calculate the measured value of the absorption of gamma rays by the calibration piece based on the second radioactivity signal and the radioactivity data of the radioactive source.

[0012] Preferably, the detector assembly also includes a first position sensor and a second position sensor, and the first position sensor and the second position sensor are both electrically connected to the data processing unit. The first position sensor is arranged at the measuring position, and is used to send a first sensing signal to the data processing unit when the detector moves to the measuring position, and the data processing unit detects the concentration of each metal element in the slurry according to the first sensing signal and the first radioactive activity signal. The second position sensor is arranged at the calibration position, and is used to send a second sensing signal to the data processing unit when the detector moves to the calibration position, and the data processing unit calibrates the detector according to the second sensing signal and the second radioactive activity signal.

[0013] Preferably, the detector is a Na I detector, an SDD detector, a cadmium zinc telluride detector or a cadmium telluride detector.

[0014] Preferably, the calibration piece is a stainless steel sheet.

[0015] Preferably, the radiation source assembly includes a turntable and a radiation source, the radiation source is mounted on the turntable, the turntable surface is vertically arranged and can rotate around its own central axis, a first position is provided on one side of the turntable, and a second position is provided on the other side, the first position and the second position are axially symmetrically arranged with the central axis of the turntable as the axis, the first position is aligned with the measuring cell, and the second position is aligned with the calibration component, the turntable is used to drive the radiation source to rotate, so that the radiation source periodically passes through the first position and the second position, thereby causing the radiation source to emit pulsed gamma rays toward the measuring cell and the calibration component.

[0016] Preferably, the radiation source is an americium source, and the activity of the americium source is 10 mCi to 300 mCi.

[0017] Preferably, it further comprises a shielding body, wherein a containing cavity is provided in the shielding body, and the calibration component, the measuring cell, the detector assembly and the radiation source assembly are all contained in the containing cavity.

[0018] Preferably, the device also includes a feed pipe and a discharge pipe, one end of the feed pipe is connected to the measuring cell, and the other end is connected to the liquid production system in the equipment room, for supplying the post-processed liquid to flow into the measuring cell; one end of the discharge pipe is connected to the measuring cell, and the other end is connected to the liquid processing system in the equipment room, for supplying the post-processed liquid that has completed the detection to flow into the post-processing liquid processing system.

[0019] According to an embodiment of the second aspect of the present invention, there is provided a post-processing online analysis system, comprising an air lifting device and the above-mentioned γ absorption online measuring device, wherein the γ absorption online measuring device is installed on the top plate of the equipment room, and the air lifting device is connected to the measuring cell in the γ absorption online measuring device, and is used to lift the post-processing liquid and input the liquid into the measuring cell.

[0020] The gamma absorption online measuring device of the present invention can emit gamma rays to the detector assembly through the radiation source assembly, and the gamma rays have two routes. In one route, the gamma rays are received by the detector assembly after passing through the measuring cell, and the post-processing liquid in the measuring cell absorbs part of the gamma rays. When the detector assembly receives the gamma rays passing through the measuring cell, it generates a first radioactivity signal according to its radioactivity. The data processing unit analyzes the concentration of each metal element in the post-processing liquid according to the first radioactivity signal. Therefore, the measuring device can detect the various element components in the post-processing liquid. In another route, the gamma rays are received by the detector assembly after passing through the calibration piece, and the calibration piece absorbs part of the gamma rays. When the detector assembly receives the gamma rays passing through the calibration piece, it generates a second radioactivity signal according to its radioactivity. The data processing unit calibrates the detector assembly according to the second radioactivity signal. Therefore, the measuring device can conveniently calibrate the detector assembly to improve the accuracy of the detector assembly, and then can more accurately detect the element components in the post-processing liquid, so as to better guide the process operation and be more widely applied to various industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a cross-sectional view of a vertical section of a gamma absorption online measurement device in some embodiments of the present invention;

[0022] Figure 2 4 is a cross-sectional view of a horizontal section of an online gamma absorption measurement device in some embodiments of the present invention.

[0023] In the figure: 1-motor, 2-motor shaft, 3-shielding body, 4-turntable, 5-radiation source, 6-measuring cell, 7-feed pipe, 8-discharge pipe, 9-detector, 10-photomultiplier tube, 11-cable, 12-data processing unit, 13-calibration piece. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "upper", "lower", "upstream", "downstream" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0026] In the description of the present invention, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0028] Example 1

[0029] See also Figure 1 and Figure 2 The present invention discloses an online γ absorption measurement device, which includes a measuring cell 6, a calibration component 13, a detector assembly, a radiation source assembly and a data processing unit 12.

[0030] The detector assembly and the radiation source assembly are arranged opposite to each other. The measuring cell 6 and the calibration piece 13 are located between the detector assembly and the radiation source assembly. The measuring cell 6 is used for the circulation of the post-processing liquid. Specifically, the measuring cell 6 is in the shape of a rectangular parallelepiped and is integrally formed of stainless steel or titanium alloy. The inner surface of the measuring cell is polished, lasered or electroplated, and is provided with chamfers. The calibration piece 13 is a stainless steel sheet.

[0031] The radiation source assembly is used to emit gamma rays to the detector assembly, and the gamma rays are provided with two routes. One of the routes is that the gamma rays are received by the detector assembly after passing through the measuring cell 6, and the other route is that the gamma rays are received by the detector assembly after passing through the calibration piece 13. The detector assembly is used to detect the radioactivity when receiving the gamma rays passing through the measuring cell 6 to generate a first radioactivity signal, or to detect the radioactivity when receiving the gamma rays passing through the calibration piece 13 to generate a second radioactivity signal. The data processing unit 12 is connected to the detector assembly, and is used to analyze the concentration of each metal element in the post-processing liquid when receiving the first radioactivity signal, or to calibrate the detector assembly when receiving the second radioactivity signal.

[0032] Specifically, the detector assembly has a measuring position and a calibration position, wherein the measuring position is aligned with the measuring pool 6, and the calibration position is aligned with the calibration piece 13. The detector assembly also includes a detector 9 and a cylinder (not shown in the figure). The cylinder is provided with a telescopic end that can be telescoped in the horizontal direction, and the telescopic end automatically moves between the calibration position and the measuring position. The telescopic end of the cylinder is connected to the detector 9, and is used to drive the detector 9 to automatically move between the measuring position and the calibration position.

[0033] The radiation source assembly is used to emit gamma rays to the measurement position and the calibration position respectively. The gamma rays emitted by the radiation source assembly to the measurement position pass through the measurement cell 6, and the post-processing liquid in the measurement cell 6 can absorb the gamma rays. When the detector 9 moves to the measurement position, it can receive the gamma rays absorbed by the post-processing liquid in the measurement cell 6 and detect its radioactivity.

[0034] Furthermore, the detector assembly also includes a photomultiplier tube. The detector 9 is connected to the data processing unit 12 via the photomultiplier tube 10. After receiving the gamma rays absorbed by the post-processing liquid in the measuring cell 6, the detector 9 generates a first light signal according to its radioactivity, and sends the first light signal to the photomultiplier tube 10.

[0035] The detector 9 is a NaI detector 9. The gamma ray can excite the NaI crystal to release scintillation photons, which are the first light signal. The intensity of the released scintillation photons is related to the radioactivity of the gamma ray. Therefore, the detector 9 can generate the first light signal according to the radioactivity of the gamma ray. Of course, it is understandable that the detector 9 can also be an SDD detector 9, a cadmium zinc telluride detector 9 or a cadmium telluride detector 9.

[0036] The photomultiplier tube 10 converts the first light signal into a first electrical signal, amplifies the first electrical signal to generate a first radioactivity signal, and sends the first radioactivity signal to the data processing unit 12. Specifically, the detector 9 is connected to the photomultiplier tube 10 through a light guide. The scintillation photons (i.e., the first light signal) generated by the detector 9 are injected into the photocathode of the photomultiplier tube 10 through the light guide and emit photoelectrons. The photoelectrons are accelerated by the strong electric field between the dynodes and bombard the next dynode to emit more photoelectrons, thereby achieving the multiplication of photoelectrons until they finally reach the anode and are in the output loop, so that the photomultiplier tube 10 generates a first electrical signal. The photomultiplier tube 10 is also used to amplify the first electrical signal to generate a first radioactivity signal. The photomultiplier tube 10 is connected to the data processing unit 12 through a cable 11, and the first radioactivity signal is sent to the data processing unit 12.

[0037] It is worth noting that Figure 2 As shown, in this embodiment, the angle between the center extension line of the detector 9 and the center extension line of the photomultiplier tube 10 is equal to or greater than 90°, which can effectively prevent the photomultiplier tube 10 from being directly irradiated by gamma rays, thereby effectively improving the service life of the photomultiplier tube 10.

[0038] The data processing unit 12 is used to determine the absorption amount of gamma rays by the post-processing liquid according to the first radioactivity signal, and then detect the concentration data of each metal element in the liquid, and output the concentration data of each metal element. Specifically, the data processing unit 12 calculates the radioactivity data of the gamma rays received by the detector 9 according to the first radioactivity signal. Moreover, the data processing unit 12 can obtain the radioactivity data of the radioactive source 5, and then compare the radioactivity data of the gamma rays absorbed by the post-processing liquid with the radioactivity data of the radioactive source 5 to obtain the absorption amount of gamma rays by the post-processing liquid. Because different elements have different absorption coefficients for gamma rays, for example: the absorption coefficient of light elements for gamma photons is not large, while the absorption coefficient of heavy elements such as uranium, plutonium, and lead is very large. Therefore, the data processing unit 12 can measure the content of each metal element in the post-processing liquid according to the absorption amount of gamma rays by the post-processing liquid.

[0039] In addition, in order to realize the online measurement function of the post-processed liquid, the device also includes a feed pipe 7 and a discharge pipe 8. One end of the feed pipe 7 is connected to the measuring cell 6, and the other end is connected to the liquid production system in the equipment room, so as to allow the post-processed liquid to flow into the measuring cell. One end of the discharge pipe is connected to the measuring cell, and the other end is connected to the liquid processing system in the equipment room, so as to allow the post-processed liquid that has completed the detection to flow into the post-processing liquid processing system. Therefore, the post-processed liquid can continuously flow through the measuring cell 6 to realize the online measurement function of the post-processed liquid.

[0040] More specifically, the lower end of the measuring cell 6 is provided with a feed port, and the upper end is provided with a discharge port. The feed pipe 7 is connected to the feed port, and is used to transfer the post-processing liquid to the measuring cell 6. When the liquid level of the post-processing liquid in the measuring cell accumulates to a certain height, it overflows through the discharge port. The discharge port is connected to the discharge pipe 8, and is used to supply the post-processing liquid to flow back to the equipment room.

[0041] Therefore, this measuring device can realize the online measurement of post-processing liquid, and analyze the content of each component in the post-processing liquid based on the γ absorption method. Compared with conventional sampling analysis, this measuring device has the advantages of no need for any chemical treatment, no destruction of liquid flow, continuous measurement, etc., and can provide measurement results in real time to facilitate process parameter adjustment and remote operation.

[0042] In this embodiment, since the detector 9 is in long-term use, the staff needs to frequently calibrate the detector 9. When the detector 9 needs to be calibrated, the detector 9 is moved to the calibration position by the cylinder.

[0043] The gamma rays emitted by the radiation source assembly to the calibration position pass through the calibration piece 13, and the calibration piece 13 can absorb the gamma rays. When the detector 9 is in the calibration position, it can receive the gamma rays absorbed by the calibration piece, detect its radioactivity, and generate a second optical signal according to its radioactivity, and send the second optical signal to the photomultiplier tube 10. The photomultiplier tube 10 is also used to convert the second optical signal into a second electrical signal, amplify the second electrical signal to generate a second radioactivity signal, and send the second radioactivity signal to the data processing unit 12. The data processing unit 12 determines the amount of gamma rays absorbed by the calibration piece 13 based on the second radioactivity signal, and then calibrates the detector 9.

[0044] Specifically, the calibration piece 13 is a stainless steel sheet. The principle of the data processing unit 12 calibrating the detector 9 is as follows: since the material selection and thickness of the calibration piece 13 are fixed, there is a standard value for the absorption of gamma rays by the calibration piece 13, and the standard value of the absorption of gamma rays by the calibration piece 13 is pre-stored in the data processing unit 12. The data processing unit 12 calculates the radioactivity of the gamma rays absorbed by the calibration piece 13 according to the second radioactivity signal, and then compares the radioactivity of the gamma rays absorbed by the calibration piece 13 with the radioactivity data of the radiation source 5 to obtain the measured value of the absorption of gamma rays by the calibration piece 13. Further, the data processing unit 12 compares the measured value of the absorption of the calibration piece 13 with the standard value. If the difference between the measured value and the standard value is within the allowable range, it is considered that the probe is working normally and can continue to be used, and then the data processing unit 12 controls the end of calibration. If the difference between the measured value and the standard value is greater than the allowable range, the data processing unit 12 sends a reminder signal to remind the staff to inspect the detector 9.

[0045] In the previous γ absorption online measurement device, the staff had to dismantle the detector 9 and send it to the laboratory for calibration. However, the present measurement device does not need to dismantle the detector 9. The detector 9 can be calibrated by simply moving it to the calibration position through the cylinder. Therefore, compared with the previous online measurement device, the present measurement device can realize the online calibration of the detector, making it convenient for the staff to calibrate the detector 9, and then more accurately detect the elemental composition in the post-processing liquid, so as to better guide the process operation and be more widely used in various industries.

[0046] Since the radioactivity of the radioactive source 5 decays over time, its radioactivity data will also change over time. If the radioactivity of the radioactive source 5 is not corrected, it may cause errors in the absorption of gamma rays by the post-processing liquid calculated by the data processing unit 12 and the absorption of gamma rays by the calibration piece 13. Therefore, in this embodiment, the gamma absorption online measurement device also includes an attenuation correction unit. The attenuation correction unit is connected to the data processing unit 12, and is used to perform attenuation correction calculation on the radioactivity of the radioactive source 5, and transmit the radioactivity data of the radioactive source 5 obtained by the attenuation correction calculation to the data processing unit 12. The data processing unit 12 calculates the absorption of gamma rays by the post-processing liquid based on the first radioactivity signal and the radioactivity data of the radioactive source 5. The data processing unit 12 can also calculate the measured value of the absorption of gamma rays by the calibration piece 13 based on the second radioactivity signal and the radioactivity data of the radioactive source 5.

[0047] Specifically, the principle of the attenuation correction unit for the radiation source 5 is that since the half-life of the radiation source 5 is a fixed value, there is a corresponding relationship between the actual radioactivity of the radiation source 5 and the half-life and decay time of the radiation source 5. Therefore, the attenuation correction unit can calculate the change value of the radioactivity of the radiation source over time through the corresponding relationship.

[0048] More specifically, the attenuation correction unit pre-stores the initial radioactivity of the radioactive source 5 and the correction function, and the radioactivity of the radioactive source 5 at the current time can be calculated by the correction function. The calibration function is: A = A0e -λt Among them, A is the corrected radioactivity of the radioactive source 5; A0 is the initial radioactivity of the radioactive source 5; λ is the half-life constant (i.e., λ = ln2 / T 1 / 2 , where T 1 / 2 is the half-life of the radioactive source 5), and t is the time.

[0049] The attenuation correction unit also pre-stores a calculation step length. In each calculation step length, the attenuation correction unit performs an attenuation correction calculation on the radiation source and transmits the radioactivity data after attenuation correction to the data processing unit 12. The attenuation correction unit can be a computing device such as an industrial computer.

[0050] By performing attenuation correction on the radioactivity data of the radioactive source 5 in the data processing unit 12 through the attenuation correction unit, the accuracy of the concentration analysis of each element in the post-processing liquid by the measuring device can be improved.

[0051] In order to enable the data processing unit 12 to identify the position of the detector 9 and switch different functions according to the position of the detector 9, in this embodiment, the detector assembly also includes a first position sensor (not shown in the figure) and a second position sensor (not shown in the figure). The first position sensor and the second position sensor are both electrically connected to the data processing unit 12. The first position sensor is arranged at the measuring position, and is used to send a first sensing signal to the data processing unit 12 when the detector 9 moves to the measuring position. The data processing unit 12 detects the concentration of each metal element in the slurry according to the first sensing signal and the first radioactive activity signal. The second position sensor is arranged at the calibration position, and is used to send a second sensing signal to the data processing unit 12 when the detector 9 moves to the calibration position. The data processing unit 12 calibrates the detector 9 according to the second sensing signal and the second radioactive activity signal.

[0052] Please continue to refer to Figure 1 and Figure 2 In this embodiment, the radiation source assembly includes a turntable 4 and a radiation source 5, and the radiation source 5 is installed on the turntable 4. The turntable 4 is vertically arranged and can rotate around its central axis. Specifically, the device also includes a motor 1, which is connected to the turntable 4 through a motor shaft 2 and is used to drive the turntable 4 to rotate.

[0053] A first position is provided on one side of the turntable 4, and a second position is provided on the other side, and the first position and the second position are symmetrically arranged with the central axis of the turntable 4 as the axis. The first position is aligned with the measuring cell 6, and the second position is aligned with the calibration piece 13. The turntable 4 is used to drive the radiation source 5 to rotate, so that the radiation source 5 periodically passes through the first position and the second position, and then the radiation source 5 emits pulsed gamma rays to the measuring cell 6 and the calibration piece 13.

[0054] Therefore, when the detector 9 is in the measuring position, it can receive the pulsed gamma rays absorbed by the post-processing liquid in the measuring cell 6 ; when the detector 9 is in the calibration position, it can receive the pulsed gamma rays absorbed by the calibration piece 13 .

[0055] It should be noted that the post-processing process liquid has a high radioactive background, which causes great interference to the radiation received by the detector 9, resulting in reduced measurement accuracy and inability to effectively guide process operation. In addition, the previous γ absorption online measurement device cannot effectively deduct the radioactive background of the post-processing liquid.

[0056] The measuring device emits pulsed gamma rays to the measuring pool 6, and the detector 9 at the measuring position receives the pulsed gamma rays absorbed by the post-processing liquid in the measuring pool 6, and generates a plurality of first radioactivity signals. Meanwhile, during the rotation of the turntable, when the radiation source turns away from the flow pool, the detector 9 only receives the local signal of the liquid. The data processing unit 12 can measure and deduct the radioactive background of the post-processing liquid according to the plurality of first radioactivity signals, thereby improving the accuracy of the online analysis.

[0057] Furthermore, there are multiple radioactive sources 5, and the multiple radioactive sources 5 are all installed on the disk surface of the turntable 4 and are evenly arranged along the circumference of the disk surface. The turntable 4 drives these radioactive sources 5 to periodically pass through the first position and the second position. Of course, it is understandable that the more radioactive sources 5 there are, the higher the frequency of the radioactive source assembly emitting pulsed gamma rays to the detector 9, the more times the data processing unit 12 performs analysis and calculation, and the more accurate the concentration of each metal element in the post-processing liquid is detected. However, if the pulse frequency of the gamma ray is too high, the load of the data processing unit 12 will be too large, which is not conducive to extending the service life. Therefore, preferably, the number of radioactive sources 5 is two.

[0058] Furthermore, the radiation source 5 is an americium source, and the activity of the americium source is 10 mCi to 300 mCi.

[0059] In this embodiment, the measuring device further includes a shielding body 3. A containing cavity is provided in the shielding body 3, and the calibration component 13, the measuring cell 6, the detector assembly and the radiation source assembly are all contained in the containing cavity to shield the influence of external radiation on the detector 9 and improve the analysis accuracy of the concentration of each element.

[0060] In addition, if Figure 1 As shown, the motor 1 is installed at the upper end of the shielding body 3. The data processing unit 12 is arranged outside the shielding body 3. It is worth noting that Figure 1 The position of the data processing unit 12 in the figure is only for illustration, and the data processing unit 12 may also be located away from the shielding body 3. Specifically, the data processing unit 12 may be an industrial computer or a mobile computer, so that the staff can directly observe the concentration data of each metal element in the post-processing liquid through the processing unit 12, and it is convenient for the staff to inspect and repair the data processing unit 12.

[0061] The present measuring device realizes modular design by fixing the calibration part 13, the measuring cell 6, the detector assembly and the radiation source assembly in the shielding body 3. When a certain component needs to be repaired, the staff can directly disassemble the components in the entire shielding body 3 and move them out together for easy maintenance. Specifically, the present shielding body 3 can be installed in the equipment room of a nuclear facility. When the components in the shielding body 3 need to be repaired, they can be transported to the maintenance station as a whole through a special maintenance container for maintenance, or they can be brought out nearby through a lifting device for on-site maintenance. During the lifting process, the seal of the equipment room will not be damaged.

[0062] It should be further explained that the existing γ absorption online measurement device cannot be flexibly arranged. The niche-type online analyzer must be arranged in the partition wall between the equipment room and the orange zone, which causes the wall radiation shielding to be thinned, which may cause the radiation dose to exceed the standard; the glove box-type online analyzer is arranged in the orange zone room close to the equipment room, and a special corridor for online analysis is required. If it is arranged in an exhaust corridor or a detection corridor, it is very likely to cause interference with air ducts, bridges, etc., which has a great impact on the layout of the plant. However, this measurement device is modularly designed to meet a variety of layout methods, including cover type, glove box type, niche type, etc. Therefore, this measurement device has strong flexibility during installation.

[0063] The gamma absorption online measurement device can automatically move the detector 9 between the measurement position and the calibration position through the cylinder to achieve the switching between the online measurement function and the calibration function. The specific working process is as follows:

[0064] When it is necessary to measure the elemental composition of the post-processed liquid in the measuring cell 6, the detector 9 is moved to the measuring position by the cylinder. At this time, the gamma rays emitted by the radiation source 5 pass through the measuring cell and are received by the detector 9, and the post-processed liquid in the measuring cell 6 can absorb part of the gamma rays. The detector 9 detects the radioactivity of the gamma rays absorbed by the post-processed liquid, and generates a first light signal based on its radioactivity. The photomultiplier tube 10 generates a first radioactivity signal based on the first light signal, and sends the first radioactivity signal to the data processing unit 12. The data processing unit 12 calculates the absorption of gamma rays by the post-processed liquid based on the first radioactivity signal and the radioactivity data of the radiation source 5 corrected by the attenuation correction unit, and then analyzes the concentration data of each metal element in the post-processed liquid.

[0065] When the detector 9 needs to be calibrated, the detector 9 is moved to the calibration position by the cylinder. At this time, the gamma rays emitted by the radiation source 5 pass through the calibration piece 13 and are received by the detector 9, and the calibration piece 13 can absorb part of the gamma rays. The detector 9 generates a second light signal according to the radioactivity of the gamma rays. The photomultiplier tube 10 generates a second radioactivity signal according to the second light signal, and sends the second radioactivity signal to the data processing unit 12. The data processing unit 12 measures the absorption of the gamma rays by the calibration piece according to the second radioactivity signal and the radioactivity of the radiation source 5 corrected by the attenuation correction unit, and compares the measured value of the absorption with the standard value. If the difference between the measured value and the standard value is greater than the allowable range, the data processing unit 12 sends a reminder signal to remind the staff to inspect the detector 9.

[0066] It is worth noting that in other embodiments, the positions of the detector 9 and the radiation source 5 in the measuring device may also be fixed, and the switching between the online measurement function and the calibration function is achieved by horizontally moving the measuring cell 6 and the calibration piece 13.

[0067] In summary, the γ absorption online measurement device has the following advantages:

[0068] 1. The detector 9 can be conveniently calibrated online;

[0069] 2. It can deduct the radioactive background of the post-processing liquid in real time, effectively improving the accuracy of the measurement;

[0070] 3. The modular design facilitates the precise positioning of the measuring components and the calibration components. On the other hand, they can be removed together when maintenance is required, which is convenient for maintenance. In addition, the seal with the equipment room will not be damaged during the lifting process.

[0071] 4. It can adapt to various layout types such as cover type, glove box type, niche type, etc., and has strong flexibility.

[0072] 5. By arranging the detector 9 and the photomultiplier tube 10 vertically, the irradiation of the photomultiplier tube 10 by gamma rays is effectively avoided, thereby increasing the life of the photomultiplier tube 10.

[0073] 6. The measuring cell 6 is made of stainless steel or titanium alloy in one piece, ensuring maintenance-free during the entire service life.

[0074] Example 2

[0075] The present invention also discloses a post-processing online analysis system, comprising an air lifting device, and characterized in that it also comprises the γ absorption online measurement device in embodiment 1.

[0076] Among them, the γ absorption online measurement device is installed on the top plate of the equipment room, and the air lifting device is connected to the measurement pool 6 in the γ absorption online measurement device, which is used to lift the post-processing liquid and input the liquid into the measurement pool 6.

[0077] Specifically, the air lift device is connected to the feed pipe 7 of the gamma absorption online measuring device, and is fed into the measuring cell 6 by air lift. When the liquid level of the post-processed liquid in the measuring cell 6 reaches a certain height, it overflows from the discharge port and flows back to the liquid processing system in the equipment room through the discharge pipe 8.

[0078] Therefore, the measuring device can realize the online measurement of the post-processing liquid, and analyze the content of each component in the post-processing liquid based on the γ absorption method. Moreover, the measuring device has the advantages of not destroying the liquid flow, continuous measurement, etc., and can provide measurement results in real time to facilitate process parameter adjustment and realize remote operation.

[0079] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A γ absorption online measurement device, characterized in that: include: A measuring cell (6), a calibration component (13), a detector assembly, a radiation source assembly and a data processing unit (12), The detector assembly and the radiation source assembly are arranged relative to each other. The measuring cell (6) and the calibration component (13) are located between the detector assembly and the radiation source assembly. The measuring cell (6) is used for the post-processing liquid to flow through. The radiation source assembly is used to emit gamma rays to the detector assembly, and the gamma rays are received by the detector assembly after passing through a measuring cell or a calibration piece (13). The detector assembly is used to detect the radioactivity of gamma rays passing through the measuring cell (6) when receiving the gamma rays, so as to generate a first radioactivity signal, or to detect the radioactivity of gamma rays passing through the calibration piece (13) when receiving the gamma rays, so as to generate a second radioactivity signal. The data processing unit (12) is connected to the detector assembly and is used to analyze the concentration of each metal element in the post-processing liquid according to the first radioactivity signal when receiving the first radioactivity signal, or to calibrate the detector assembly when receiving the second radioactivity signal; The detector assembly comprises a detector (9), and the detector (9) is movable between two positions: a measuring position and a calibration position. The measuring position is aligned with the measuring cell (6), and the calibration position is aligned with the calibration piece (13). The radiation source assembly is used to emit gamma rays to the measuring position and the calibration position respectively. The gamma rays emitted to the measuring position pass through the measuring cell (6), and the post-processing liquid in the measuring cell (6) can absorb the gamma rays. The gamma rays emitted to the calibration position pass through the calibration piece (13), and the calibration piece (13) can absorb the gamma rays. The detector is used to detect the radioactivity of the gamma rays absorbed by the post-processing liquid in the measuring cell when it is in the measuring position, and to detect the radioactivity of the gamma rays absorbed by the calibration piece when it is in the calibration position.

2. The device according to claim 1, characterized in that The detector assembly further comprises a photomultiplier tube, and the detector (9) is connected to the data processing unit via the photomultiplier tube (10). The detector (9) is used to generate a first light signal according to the radioactivity after receiving the gamma rays absorbed by the post-processing liquid in the measuring cell, and send the first light signal to the photomultiplier tube (10). The photomultiplier tube (10) is used to convert the first optical signal into a first electrical signal, and amplify the first electrical signal to generate the first radioactivity signal, and send the first radioactivity signal to a data processing unit. The data processing unit (12) is used to determine the absorption amount of gamma rays by the post-processing liquid according to the first radioactivity signal, thereby detecting the concentration data of each metal element in the liquid and outputting the concentration data of each metal element.

3. The device according to claim 2, characterized in that The detector assembly also includes a cylinder, the telescopic end of which is connected to the detector and is used to drive the detector to automatically move between a measuring position and a calibration position. When the detector (9) moves to the calibration position, it is used to receive the gamma rays absorbed by the calibration piece, generate a second light signal according to the radioactivity thereof, and send the second light signal to the photomultiplier tube (10). The photomultiplier tube (10) is further used to convert the second optical signal into a second electrical signal, and to amplify the second electrical signal to generate a second radioactivity signal, and to send the second radioactivity signal to the data processing unit (12). The data processing unit (12) is used to calculate a measured value of the absorption amount of the gamma ray by the calibration piece (13) according to the second radioactivity signal, and The data processing unit (12) pre-stores a standard value of the amount of gamma ray absorption by the calibration component (13), and the data processing unit (12) is further used to compare the measured value with the standard value, and to issue a warning signal when the difference between the measured value and the standard value is greater than an allowable range.

4. The device according to claim 3, characterized in that The device also comprises an attenuation correction unit, which is electrically connected to the data processing unit and is used to perform attenuation correction calculation on the radioactivity of the radioactive source (5) and transmit the obtained radioactivity data of the radioactive source (5) to the data processing unit (12). The data processing unit (12) is used to calculate the absorption amount of gamma rays by the post-processing liquid according to the first radioactivity signal and the radioactivity data of the radioactive source (5), and to calculate the measured value of the absorption amount of gamma rays by the calibration piece (13) according to the second radioactivity signal and the radioactivity data of the radioactive source (5).

5. The device according to claim 4, characterized in that The detector assembly further comprises a first position sensor and a second position sensor, wherein the first position sensor and the second position sensor are both electrically connected to the data processing unit (12). The first position sensor is arranged at the measuring position and is used to send a first sensing signal to the data processing unit (12) when the detector (9) moves to the measuring position. The data processing unit (12) detects the concentration of each metal element in the slurry according to the first sensing signal and the first radioactivity signal. The second position sensor is arranged at the calibration position, and is used to send a second sensing signal to the data processing unit (12) when the detector (9) moves to the calibration position, and the data processing unit (12) calibrates the detector (9) according to the second sensing signal and the second radioactivity activity signal.

6. The device according to any one of claims 1 to 5, characterized in that: The detector (9) is a NaI detector, an SDD detector, a cadmium zinc telluride detector or a cadmium telluride detector.

7. The device according to any one of claims 1 to 5, characterized in that: The calibration piece (13) is a stainless steel sheet.

8. The device according to claim 1, characterized in that The radiation source assembly comprises a turntable (4) and a radiation source (5), wherein the radiation source (5) is mounted on the turntable (4). The surface of the turntable (4) is arranged vertically and can rotate around its own central axis. A first position is arranged on one side of the turntable (4) and a second position is arranged on the other side. The first position and the second position are arranged symmetrically with the central axis of the turntable (4). The first position is aligned with the measuring cell (6), and the second position is aligned with the calibration piece (13). The turntable (4) is used to drive the radiation source (5) to rotate, so that the radiation source periodically passes through the first position and the second position, thereby causing the radiation source to emit pulsed gamma rays toward the measuring cell (6) and the calibration piece (13).

9. The device according to claim 8, characterized in that The radiation source (5) is an americium source, and the activity of the americium source is 10 mCi to 300 mCi.

10. The device according to claim 1, characterized in that It also comprises a shielding body (3), wherein a containing cavity is provided in the shielding body (3), and the calibration component (13), the measuring cell (6), the detector assembly and the radiation source assembly are all contained in the containing cavity.

11. The device according to claim 1, characterized in that The device also includes a feed pipe (7) and a discharge pipe (8), One end of the feed pipe (7) is connected to the measuring cell, and the other end is connected to the feed liquid production system in the equipment room, so as to allow the post-processed feed liquid to flow into the measuring cell. One end of the discharge pipe (8) is connected to the measuring cell (6), and the other end is connected to the liquid processing system in the equipment room, so as to allow the post-processed liquid that has completed the test to flow into the post-processed liquid processing system.

12. A post-processing online analysis system, comprising an air lifting device, characterized in that: It also includes the gamma absorption online measurement device according to any one of claims 1 to 11, The gamma absorption online measuring device is installed on the top plate of the equipment room, and the air lifting device is connected to the measuring cell (6) in the gamma absorption online measuring device, and is used to lift the post-processing liquid and input the liquid into the measuring cell (6).

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