A uranium measuring instrument field calibration device and calibration method

Abstract

The application provides a uranium measuring instrument field calibration device and a calibration method, and belongs to the technical field of nuclear radiation monitoring and environmental analysis instrument, the device comprises a standard solution module, a transfer instrument, a calibration loop unit and a recovery system module, the standard solution module is connected with the calibration loop unit through a pipeline, the calibration loop unit comprises a first calibration loop and a second calibration loop, the calibration loop unit is connected with the transfer instrument through a pipeline, the recovery system module is connected with the calibration loop unit through a pipeline, the first calibration loop comprises a first pump circulation system, a first flow controller, a first quantitative sampler and a radioactive solution recovery system, and the second calibration loop comprises a second pump circulation system, a second flow controller and a second quantitative sampler. The uranium measuring instrument field calibration device and the calibration method are adopted, and the problems of long period, complex operation, inability to implement on site, insufficient range coverage and poor uncertainty control of the existing calibration mode are solved.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation monitoring and environmental analysis instruments, and in particular to a field calibration device and calibration method for a uranium measuring instrument. Background Technology

[0002] The mining, refining, and processing of uranium ore generate large amounts of uranium-containing wastewater. If this wastewater is not rigorously monitored and properly treated, it will cause serious radioactive pollution to aquatic environments, thereby threatening public health and the safety and stability of ecosystems. Therefore, accurate monitoring of uranium concentration is crucial throughout the entire lifecycle of the nuclear industry, from raw material extraction to waste disposal, and is a core aspect of radiation protection, environmental protection, and safe production.

[0003] As a key device for rapid, on-site monitoring of uranium concentration, the accuracy and reliability of uranium measuring instruments directly determine the effectiveness of environmental risk early warning and the targeted nature of radiation protection measures. Although modern uranium measuring instruments have broken free from the constraints of traditional laboratory analysis and achieved rapid on-site measurement, they still face many challenges in the calibration process. Currently, the calibration of uranium measuring instruments mainly relies on standard materials and static comparison methods provided by the laboratory. This approach cannot simulate the dynamic flow conditions in actual applications under field conditions, leading to significant deviations between calibration results and actual usage scenarios.

[0004] Specifically, existing calibration devices struggle to cover a wide measurement range from 0.2 mg / L to 2 g / L, limiting their application in monitoring wastewater of varying concentrations. Under dynamic conditions, fluctuations in flow rate and temperature variations can easily increase calibration errors, resulting in expanded uncertainties typically exceeding 5%, which fails to meet the requirements for high-precision measurements. Some calibration devices also have deficiencies in wastewater recovery, potentially leading to radioactive material leaks and posing environmental safety hazards. The lack of flexible calibration mode switching capabilities prevents adaptation to different field environments, limiting the flexibility and applicability of calibration. These issues not only restrict the accuracy and reliability of uranium measuring instruments in field monitoring but also increase the difficulty of environmental safety management in the nuclear industry. Summary of the Invention

[0005] The purpose of this invention is to provide a field calibration device and method for uranium measuring instruments, which solves the problems of long calibration cycles, complex operation, inability to be implemented on-site, insufficient range coverage, and poor uncertainty control of existing calibration methods, and realizes dynamic, real-time, and traceable calibration of uranium measuring instruments.

[0006] To achieve the above objectives, the present invention provides a field calibration device for a uranium measuring instrument. The device includes a standard solution module, a transfer instrument, a calibration loop unit, and a recovery system module. The standard solution module is connected to the calibration loop unit via a pipeline. The calibration loop unit includes a first calibration loop and a second calibration loop. The calibration loop unit is connected to the transfer instrument via a pipeline. The recovery system module is connected to the calibration loop unit via a pipeline. The first calibration loop includes a first pump circulation system, a first flow controller, a first quantitative sampler, and a radioactive solution recovery system. The second calibration loop includes a second pump circulation system, a second flow controller, and a second quantitative sampler.

[0007] Preferably, the device further includes a control module and a data processing module. The device is externally connected to the instrument being calibrated. The control module is connected to the calibration loop unit via a signal line, and the data processing module is connected to the transmission instrument and the instrument being calibrated via signal lines respectively.

[0008] Preferably, the first pump circulation system is connected to the first flow controller via a pipeline, the first flow controller is connected to the first quantitative sampler via a pipeline, the outlet of the first quantitative sampler is connected to the first pump circulation system via a pipeline, and the radioactive solution recovery system is connected to the output end of the first pump circulation system via a pipeline.

[0009] Preferably, the second pump circulation system is connected to the second flow controller via a pipeline, the second flow controller is connected to the second quantitative sampler via a pipeline, and the second quantitative sampler is connected to the transfer instrument and the calibrated instrument via pipelines respectively.

[0010] Preferably, the standard solution module includes a high-concentration standard uranium solution container and a low-concentration standard uranium solution container, the transfer instrument includes a uranium measuring instrument based on laser fluorescence method, and the recovery system module includes a sealed container with radiation shielding.

[0011] A method for on-site calibration of a uranium measuring instrument includes the following steps:

[0012] S1. Preparation before calibration: Place the calibration device under standard working conditions, connect the power supply and set the parameters through the control module, preheat the calibration device for no less than 30 minutes, until the fluctuation range of the calibration device reading is reduced to within ±1%.

[0013] S2. Calibration Mode Selection: Select one of the following four calibration modes to operate according to actual calibration needs:

[0014] Mode 1 involves directly using a standard solution for calibration. The prepared standard solution is added to the instrument being calibrated, and the calibration process is completed by comparing the measured value of the instrument with the known concentration of the standard solution.

[0015] Mode 2 involves calibrating the instrument under test by combining a standard solution with the first calibration loop. The instrument under test is connected to the first calibration loop, and a standard solution is added to simulate the dynamic flow of the solution.

[0016] Mode 3 involves comprehensive calibration using standard solutions, a first calibration loop, a second calibration loop, and a transfer instrument. The transfer instrument is set using the first calibration loop, and then both the transfer instrument and the instrument being calibrated are measured simultaneously in the second calibration loop. The calibration is completed by comparing the readings.

[0017] Mode 4, based on Mode 3, involves obtaining the measurement value from the transfer instrument by diluting the high-concentration solution at a fixed ratio.

[0018] S3. Standard addition measurement: Take 4.50 mL of sample and add 0.50 mL of deionized water. After mixing well, measure its fluorescence intensity as the background value N0. Take the same volume of sample and add 0.50 mL of fluorescence enhancer. Measure its fluorescence intensity as the sample value N1. Add a uranium standard solution of known concentration to the sample solution and perform spiking measurement N2. Calculate the uranium concentration in the sample based on the concentration and volume parameters of the standard solution.

[0019] S4. Calculate the calibration factor. Based on the predetermined low-concentration calibration procedure, accurately calculate the calibration factor using the ratio between the standard solution concentration and the instrument measurement value.

[0020] S5. Adjustment of operating parameters: Static calibration directly uses standard solutions for comparison, without the need to adjust flow parameters; Dynamic calibration requires setting the flow range between 0.6 and 15 L / min through the first calibration loop to simulate actual solution flow conditions.

[0021] S6. Stability and repeatability verification: Perform multiple repeated measurements on the same solution to verify whether the expanded uncertainty of the multiple measurements meets the requirement of being less than or equal to 5%.

[0022] S7. Wastewater recycling and treatment: The radioactive wastewater generated during the calibration process is collected and treated through the recycling system module.

[0023] Preferably, the expression for calculating the uranium concentration in the sample is:

[0024] ;

[0025] Where C1 is the concentration of the standard solution. This refers to volume parameters.

[0026] Preferably, the calibration factor expression is:

[0027] ;

[0028] in, The concentration of the standard solution. These are instrument measurements.

[0029] Preferably, during the dynamic calibration process, data should be recorded after 5 to 10 minutes of stable operation, and the flow fluctuation should be controlled within ±1%.

[0030] Therefore, the technical effects of the above-mentioned on-site calibration device and calibration method for uranium measuring instruments in this invention are as follows:

[0031] 1. High calibration accuracy: It has two calibration modes, static and dynamic. The dynamic mode can simulate the working conditions of solution flow, and the calibration expanded uncertainty is ≤5%, and the value transfer is reliable.

[0032] 2. High calibration flexibility: Supports switching between more than three calibration modes to adapt to diverse field scenarios such as emergency and routine operations;

[0033] 3. Wide calibration range: It can adapt to the calibration needs of wastewater with different concentrations without changing the standard system, covering the full range of calibration from 0.2mg / L to 2g / L;

[0034] 4. High environmental safety factor: The integrated radiation shielding recovery system enables the sealed recovery of radioactive wastewater throughout the entire process. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the principle of an on-site calibration device for a uranium measuring instrument according to the present invention;

[0036] Figure 2 This is a schematic diagram of the first calibration loop of the on-site calibration device for a uranium measuring instrument according to the present invention;

[0037] Figure 3 This is a schematic diagram of the second calibration loop of the on-site calibration device for a uranium measuring instrument according to the present invention;

[0038] Figure 4 This is a flowchart illustrating the measurement process of an on-site calibration device for a uranium measuring instrument according to the present invention.

[0039] Figure 5 This is a flowchart illustrating the dynamic calibration process of an on-site calibration device for a uranium measuring instrument according to the present invention.

[0040] Figure 6 This is a flowchart illustrating the calculation of calibration factors in a field calibration device for a uranium measuring instrument according to the present invention. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0043] Example 1

[0044] like Figure 1 As shown, the present invention provides a field calibration device for a uranium measuring instrument, which mainly consists of six modules: a standard solution module, a transfer instrument, a calibration loop unit, a control module, a data processing module, and a recovery system module.

[0045] The standard solution module includes containers for high and low concentration standard uranium solutions, using national primary or secondary standard materials. The standard uranium solution containers are connected to the pump circulation system of the calibration loop unit via piping, ensuring that the standard solution is accurately added to the calibration loop.

[0046] The transfer instrument employs a uranium measuring instrument based on laser fluorescence, with a measurement range covering 0.2 mg / L–2 g / L. The transfer instrument is connected to the data processing module via a signal line for real-time data transmission. Simultaneously, during calibration, the transfer instrument must be connected to the calibration loop unit for synchronous measurement with the instrument being calibrated.

[0047] like Figures 2-3 As shown, the calibration loop unit includes a first calibration loop and a second calibration loop. The first calibration loop includes a first pump circulation system, a first flow controller, a first quantitative sampler, and a radioactive solution recovery system, mainly used to generate a dynamic uranium solution of standard concentration to simulate field conditions. The second calibration loop includes a second pump circulation system, a second flow controller, and a second quantitative sampler. The second quantitative sampler also serves as a radioactive solution shield and transport container, used for synchronous measurements between the instrument being calibrated and the transfer instrument. Both calibration loops circulate and dilute the standard solution through pipes and valves, and are both connected to the recovery system to ensure the safe recovery of radioactive wastewater.

[0048] The first pump circulation system is connected to the first flow controller via a pipeline. The first flow controller is connected to the first quantitative sampler via a pipeline. The outlet of the first quantitative sampler is connected to the first pump circulation system via a pipeline. The radioactive solution recovery system is connected to the output of the first pump circulation system via a pipeline. The second pump circulation system is connected to the second flow controller via a pipeline. The second flow controller is connected to the second quantitative sampler via a pipeline. The second quantitative sampler is connected to the transfer instrument and the instrument being calibrated via pipelines.

[0049] The control module uses a touchscreen as the master unit and a microcontroller, relays, and stepper motor drivers as slave units, communicating via the Modbus protocol. Relays control the solenoid valves and air pump, while the stepper motor drivers control the peristaltic pump's operation, thus automating the calibration process. The control module is connected to all components of the calibration loop unit via control lines to ensure accurate execution of the calibration process.

[0050] The data processing module includes a preamplifier, an amplifier, a microcontroller (ADC), and a data storage unit. This module connects to the transmitting instrument and the instrument being calibrated via signal lines, and is responsible for converting fluorescence signals into electrical signals, amplifying, filtering, and performing analog-to-digital conversion, ultimately completing data storage, analysis, and calibration factor calculation.

[0051] The recovery system module uses a radiation-shielded sealed container with a volume sufficient for storing calibration wastewater and features a leak-proof design. The recovery system module is connected to the radioactive solution recovery system of the calibration loop unit via piping, ensuring the safe recovery and treatment of radioactive wastewater generated during calibration.

[0052] like Figure 4 As shown, the calibration method of this uranium measuring instrument's on-site calibration device mainly includes the following steps:

[0053] S1. Preparations before calibration

[0054] Ensure the instrument's operating conditions meet the requirements: power supply voltage 220V±10%, 50HZ; operating temperature 10℃~35℃; humidity less than 85% (30℃).

[0055] Connect the instrument to the power supply, turn on the power switch and LED light source, click on the touch screen to enter the main menu, set the parameters, and preheat for at least 30 minutes until the reading fluctuation is less than 1%.

[0056] S2. Calibration Mode Selection: Select one of the following four calibration modes to operate according to actual calibration needs:

[0057] Mode 1 involves directly using a standard solution for calibration. The prepared standard solution is added to the instrument being calibrated, and the calibration process is completed by comparing the measured value of the instrument with the known concentration of the standard solution. This method has a range of 0-2 g / L and is suitable for simple and rapid calibration needs.

[0058] Mode 2 involves combining a standard solution with the first calibration loop. The instrument to be calibrated is connected to the first calibration loop, and a standard solution is added to simulate the dynamic flow of the solution. Calibration is completed by comparing the measured value of the instrument to the concentration of the standard solution. This method has a range of 0.2 mg / L to 2 g / L and is suitable for calibration scenarios that require simulation of on-site conditions.

[0059] Mode 3 utilizes a standard solution, a first calibration loop, a second calibration loop, and a transfer instrument for comprehensive calibration. The transfer instrument is set using the first calibration loop, and then both the transfer instrument and the instrument being calibrated are measured simultaneously in the second calibration loop. Calibration is completed by comparing the readings. This method can easily perform continuous multi-point measurement calibration, and the measurement range depends on the range of the transfer instrument.

[0060] Mode 4, building upon Mode 3, involves obtaining a measurement from the transfer instrument after a fixed-ratio dilution in a high-concentration solution; calibration is then completed by comparing the "transfer instrument's measurement * dilution ratio" with the measurement of the instrument being calibrated. This method can significantly increase the measurement range of the calibration device.

[0061] S3. Standard addition measurement: Take 4.50 mL of sample and add 0.50 mL of deionized water. After mixing well, measure its fluorescence intensity as the background value N0. Take the same volume of sample and add 0.50 mL of fluorescence enhancer. Measure its fluorescence intensity as the sample value N1 (target value 1000-3000 count). Add a uranium standard solution of known concentration to the sample solution and perform spiking measurement N2. Calculate the uranium concentration in the sample based on the standard solution concentration and volume parameters.

[0062] The expression for calculating the uranium concentration in a sample is:

[0063] ;

[0064] Where C1 is the concentration of the standard solution. This refers to volume parameters.

[0065] S4. Calculate the calibration factor. Based on the predetermined low-concentration calibration procedure, accurately calculate the calibration factor using the ratio between the standard solution concentration and the instrument measurement value; the specific procedure is as follows: Figure 6 As shown;

[0066] The calibration factor expression is:

[0067] ;

[0068] in, The concentration of the standard solution. These are instrument measurements.

[0069] S5. Adjusting operating parameters, such as Figure 5 As shown, static calibration directly uses a standard solution for comparison without adjusting the flow rate parameters; dynamic calibration requires setting the flow rate range between 0.6 and 15 L / min through the first calibration loop to simulate actual solution flow conditions; during dynamic calibration, data should be recorded after 5 to 10 minutes of stable operation, and the flow rate fluctuation should be controlled within ±1%.

[0070] S6. Stability and repeatability verification: Perform multiple repeated measurements on the same solution to verify whether the expanded uncertainty of the multiple measurements meets the requirement of being less than or equal to 5%.

[0071] S7. Wastewater recycling and treatment: The radioactive wastewater generated during the calibration process is collected and treated through the recycling system module.

[0072] Therefore, the present invention adopts the above-mentioned on-site calibration device and calibration method for uranium measuring instruments. By constructing an on-site calibration device for uranium measuring instruments that includes a standard solution module, a transfer instrument, a calibration loop unit, a control module, a data processing module, and a recovery system, and combining multiple calibration modes (static and dynamic) and a strict calibration process, it achieves high-precision, wide-range, dynamic real-time calibration of uranium measuring instruments under on-site conditions, ensuring the accuracy and reliability of uranium concentration monitoring throughout the entire nuclear industry chain.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for on-site calibration of a uranium measuring instrument, comprising applying an on-site calibration device for a uranium measuring instrument to on-site uranium calibration, characterized in that, The device includes a standard solution module, a transfer instrument, a calibration loop unit, and a recovery system module. The standard solution module is connected to the calibration loop unit via a pipeline. The calibration loop unit includes a first calibration loop and a second calibration loop. The calibration loop unit is connected to the transfer instrument via a pipeline. The recovery system module is connected to the calibration loop unit via a pipeline. The first calibration loop includes a first pump circulation system, a first flow controller, a first quantitative sampler, and a radioactive solution recovery system. The second calibration loop includes a second pump circulation system, a second flow controller, and a second quantitative sampler. The method includes the following steps: S1. Preparation before calibration: Place the calibration device under standard working conditions, connect the power supply and set the parameters through the control module, preheat the calibration device for no less than 30 minutes, until the fluctuation range of the calibration device reading is reduced to within ±1%. S2. Calibration Mode Selection: Select one of the following four calibration modes to operate according to actual calibration needs: Mode 1 involves directly using a standard solution for calibration. The prepared standard solution is added to the instrument being calibrated, and the calibration process is completed by comparing the measured value of the instrument with the known concentration of the standard solution. Mode 2 involves calibrating the instrument under test by combining a standard solution with the first calibration loop. The instrument under test is connected to the first calibration loop, and a standard solution is added to simulate the dynamic flow of the solution. Mode 3 involves comprehensive calibration using standard solutions, a first calibration loop, a second calibration loop, and a transfer instrument. The transfer instrument is set using the first calibration loop, and then both the transfer instrument and the instrument being calibrated are measured simultaneously in the second calibration loop. The calibration is completed by comparing the readings. Mode 4, based on Mode 3, involves obtaining the measurement value from the transfer instrument by diluting the high-concentration solution at a fixed ratio. S3. Standard addition measurement: Take 4.50 mL of sample and add 0.50 mL of deionized water. After mixing well, measure its fluorescence intensity as the background value N0. Take the same volume of sample and add 0.50 mL of fluorescence enhancer. Measure its fluorescence intensity as the sample value N1. Add a uranium standard solution of known concentration to the sample solution and perform spiking measurement N2. Calculate the uranium concentration in the sample based on the concentration and volume parameters of the standard solution. S4. Calculate the calibration factor. Based on the predetermined low-concentration calibration procedure, accurately calculate the calibration factor using the ratio between the standard solution concentration and the instrument measurement value. S5. Adjustment of operating parameters: Static calibration directly uses standard solutions for comparison, without the need to adjust flow parameters; Dynamic calibration requires setting the flow range between 0.6 and 15 L / min through the first calibration loop to simulate actual solution flow conditions. S6. Stability and repeatability verification: Perform multiple repeated measurements on the same solution to verify whether the expanded uncertainty of the multiple measurements meets the requirement of being less than or equal to 5%. S7. Wastewater recycling and treatment: The radioactive wastewater generated during the calibration process is collected and treated through the recycling system module.

2. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, The device also includes a control module and a data processing module. The device is externally connected to the instrument being calibrated. The control module is connected to the calibration loop unit via signal lines, and the data processing module is connected to the transmission instrument and the instrument being calibrated via signal lines.

3. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, The first pump circulation system is connected to the first flow controller via a pipeline. The first flow controller is connected to the first quantitative sampler via a pipeline. The outlet of the first quantitative sampler is connected to the first pump circulation system via a pipeline. The radioactive solution recovery system is connected to the output end of the first pump circulation system via a pipeline.

4. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, The second pump circulation system is connected to the second flow controller via a pipeline. The second flow controller is connected to the second quantitative sampler via a pipeline. The second quantitative sampler is connected to the transfer instrument and the instrument being calibrated via pipelines.

5. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, The standard solution module includes containers for high-concentration and low-concentration standard uranium solutions, the transfer instrument includes a uranium measuring instrument based on laser fluorescence, and the recovery system module includes a sealed container with radiation shielding.

6. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, The expression for calculating the uranium concentration in a sample is: ； Where C1 is the concentration of the standard solution. This refers to volume parameters.

7. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, The calibration factor expression is: ； in, The concentration of the standard solution. These are instrument measurements.

8. The on-site calibration method for a uranium measuring instrument according to claim 1, characterized in that, During dynamic calibration, data should be recorded after 5 to 10 minutes of stable operation, and flow fluctuations should be kept within ±1%.

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