Real-time analysis method and device for uranium and acid concentration in uranium acid solution to be measured

Abstract

The invention discloses a real-time analysis method and device for uranium and acid concentration in a uranium acid solution to be measured, the method comprising the following steps: measuring the absorbance and conductivity of the prepared uranium acid solution, and performing temperature compensation on the conductivity of the prepared uranium acid solution; establishing a parameter database of the uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation of the prepared uranium acid solution, and integrating the parameters into an array; performing surface fitting on the data in the integrated array based on MATLAB to obtain a fitted surface equation; measuring the absorbance and conductivity of the uranium acid solution to be measured, and performing temperature compensation on the conductivity of the uranium acid solution to be measured; obtaining the uranium concentration and acid concentration of the uranium acid solution to be measured by the absorbance and temperature compensation of the uranium acid solution to be measured according to the fitted surface equation. The method effectively completes the real-time analysis of uranium concentration and nitric acid concentration during the preparation of uranium-nitric acid solution in a high temperature, strong acid, and radioactive environment.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel post-processing, and in particular relates to a real-time analysis method and device for uranium and acid concentrations in a uranium acid solution to be tested. Background Art

[0002] The nuclear fuel reprocessing process requires the preparation of a large amount of nitric acid and uranium solution. During the preparation process, the concentration of nitric acid and uranium needs to be quickly analyzed to determine whether the process requirements are met. Currently, reprocessing plants mainly analyze uranium and acid concentrations through manual sampling and analysis, which has the disadvantages of long analysis time and high radiation dose for personnel.

[0003] There are many methods for analyzing uranium concentration and nitric acid concentration at home and abroad. At present, the γ absorption method is commonly used for online measurement of uranium concentration, and the electrodeless conductivity method is used for online measurement of nitric acid concentration. For example, the Chinese invention patent with the announcement number CN105115993A discloses "online measurement device for uranium concentration in solution", and the Chinese invention patent with the announcement number CN108872323A discloses "an electromagnetic nitric acid concentration online analyzer".

[0004] These devices are all used for the concentration analysis of natural uranium and nitric acid, but there is no report on the device dedicated to the real-time analysis of uranium concentration and nitric acid concentration in the uranium dissolving tank in the post-processing process. The main reason is that the uranium dissolving tank in the post-processing process is quite different from the dissolving tank in the traditional chemical process. The solution in the uranium dissolving tank is highly radioactive, highly corrosive, and has a large temperature change range, which affects the measurement results. Summary of the invention

[0005] The technical problem to be solved by the present invention is to solve the problems of cumbersome analysis process and delayed analysis result in the preparation process of uranium-nitric acid solution in the prior art, and to provide a real-time analysis method and device for uranium and acid concentrations in a uranium acid solution to be tested, so as to effectively complete the real-time analysis of uranium concentration and nitric acid concentration in the preparation process of uranium-nitric acid solution in a high temperature, strong acid and radioactive environment.

[0006] The technical solution adopted to solve the technical problem of the present invention is to provide a real-time analysis method for the concentration of uranium and acid in a uranium acid solution to be measured, comprising the following steps:

[0007] The absorbance and conductivity of the prepared uranyl acid solution are measured, and the conductivity of the prepared uranyl acid solution is temperature compensated to obtain the conductivity of the sample after temperature compensation;

[0008] Establishing a parameter database of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, and integrating the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array;

[0009] The data in the integrated array are respectively used for surface fitting based on MATLAB, with uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation;

[0010] Measure the absorbance and conductivity of the uranyl acid solution to be tested, and perform temperature compensation on the conductivity of the uranyl acid solution to be tested;

[0011] The absorbance of the uranyl acid solution to be measured and the conductivity after temperature compensation are used according to the fitted surface equation to obtain the uranium concentration and acid concentration of the uranyl acid solution to be measured.

[0012] Preferably, the fitted surface equation is:

[0013] U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY (1);

[0014] H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 - 34.56X 2 Y-126.2XY 2 -12.96Y 3 +58.97X 2 Y 2 +77.04XY 3 +3.606Y 4 (2)

[0015] Where X is the absorbance of the uranyl acid solution, Y is the conductivity after temperature compensation, U is the uranium concentration, and H is the hydrogen ion concentration in the acid.

[0016] Preferably, the correlation coefficient of the fitted surface equation is in the range of 0.99-1.

[0017] Preferably, the uranium-containing group in the uranium acid solution to be detected is a uranyl group.

[0018] Preferably, the temperature compensation formula is:

[0019]

[0020] Where ρ is the conductivity, t is the temperature, β1 is the first temperature coefficient, β2 is the second temperature coefficient, ρ T is the conductivity at the compensation temperature, and T is the compensation temperature.

[0021] Preferably, the uranium concentration of the uranium acid solution to be tested is 30 g / L to 350 g / L, the hydrogen ion concentration in the acid is 0.1 mol / L to 6 mol / L, the temperature is 0 to 80° C., and the ambient humidity is 20% to 80%.

[0022] The present invention provides an analysis device used in the above-mentioned real-time analysis method for the concentration of uranium and acid in a uranium acid solution to be measured, comprising:

[0023] The detection module is used to measure the absorbance and conductivity of the prepared uranic acid solution, send the absorbance of the prepared uranic acid solution to the data integration module, and send the conductivity of the prepared uranic acid solution to the temperature compensation module. The detection module is also used to measure the absorbance and conductivity of the uranic acid solution to be measured, send the absorbance of the uranic acid solution to be measured to the calculation module, and send the conductivity of the uranic acid solution to be measured to the temperature compensation module;

[0024] The temperature compensation module is used to perform temperature compensation on the conductivity of the prepared uranyl acid solution, obtain the sample conductivity after temperature compensation, and send it to the data integration module. The temperature compensation module is also used to perform temperature compensation on the conductivity of the uranyl acid solution to be measured, obtain the sample conductivity after temperature compensation, and send it to the calculation module;

[0025] A data integration module is used to establish a database with the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, integrate the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array, and send the array to the fitting module;

[0026] The fitting module is used to perform surface fitting based on MATLAB on the data in the array integrated by the data integration module, taking uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation;

[0027] The calculation module is used to obtain the uranium concentration and acid concentration of the uranium acid solution to be measured according to the fitted surface equation by using the absorbance of the uranium acid solution to be measured and the conductivity after temperature compensation obtained by the detection module.

[0028] Preferably, the detection module comprises:

[0029] The first detection module is used to measure the absorbance of the prepared uranic acid solution and the absorbance of the uranic acid solution to be tested respectively, send the absorbance of the prepared uranic acid solution to the data integration module, and send the absorbance of the uranic acid solution to be tested to the calculation module;

[0030] The second detection module is used to measure the conductivity of the prepared uranyl acid solution and the conductivity of the uranyl acid solution to be measured respectively, and send the conductivity of the prepared uranyl acid solution and the conductivity of the uranyl acid solution to be measured to the temperature compensation module.

[0031] Preferably, the fitted surface equation is:

[0032] U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY (1);

[0033] H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 - 34.56X 2 Y-126.2XY 2 -12.96Y 3 +58.97X 2 Y 2 +77.04XY 3 +3.606Y 4 (2)

[0034] Where X is the absorbance of the uranyl acid solution, Y is the conductivity after temperature compensation, U is the uranium concentration, and H is the hydrogen ion concentration in the acid.

[0035] Preferably, the temperature compensation formula is:

[0036]

[0037] Where ρ is the conductivity, t is the temperature, β1 is the first temperature coefficient, β2 is the second temperature coefficient, ρ T is the conductivity at the compensation temperature, and T is the compensation temperature.

[0038] The beneficial effects of the real-time analysis method and device for measuring the concentration of uranium and acid in the uranium acid solution to be measured in the present invention are as follows:

[0039] (1) This method can be directly used for real-time monitoring of uranium concentration and acid concentration in the uranium dissolution tank of the post-processing process. This method does not require sampling and analysis and can maintain long-term stability and reliability;

[0040] (2) The device overcomes the influence of temperature and uranium acid mixture system on the measurement results of uranium concentration and acid concentration;

[0041] (3) Compared with the single measurement method for determining the uranium concentration and acid concentration in the solution, the error of the device is smaller and the acid concentration and uranium concentration data obtained are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of the real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured in Example 2 of the present invention;

[0043] Figure 2is a structural block diagram of an analysis device in Embodiment 2 of the present invention;

[0044] Figure 3 is a schematic diagram of the structure of the analysis device in Example 2 of the present invention;

[0045] Figure 4 is a schematic diagram of the structure of the uranium concentration probe in Example 2 of the present invention;

[0046] Figure 5 It is a schematic diagram of the structure of the acid concentration probe in Example 2 of the present invention.

[0047] In the figure: 1-uranium concentration probe; 2-acid concentration probe; 3-acid signal transmitter; 4-uranium signal transmitter; 5-control panel; 6-mounting flange; 7-connecting cable; 8-radiation source; 9-lead tank; 10-test solution; 11-observation channel; 12-collimation hole; 13-photomultiplier tube; 14-sodium iodide crystal; 15-detection circuit; 16-terminal; 17-excitation coil; 18-detection coil; 19-temperature detector; 20-polytetrafluoroethylene shell; 21-measurement center inner hole; 22-signal lead wire; 23-stainless steel support connecting pipe; 24-uranium concentration probe access port; 25-acid concentration probe access port; 26-M12 fixing bolt; 27-lead shielding layer; 28-uranium dissolution tank. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0049] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0050] Example 1

[0051] This embodiment provides a real-time analysis method for uranium and acid concentrations in a uranium acid solution to be measured, comprising the following steps:

[0052] The absorbance and conductivity of the prepared uranyl acid solution are measured, and the conductivity of the prepared uranyl acid solution is temperature compensated to obtain the conductivity of the sample after temperature compensation;

[0053] Establishing a parameter database of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, and integrating the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array;

[0054] The data in the integrated array are respectively used for surface fitting based on MATLAB, with uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation;

[0055] Measure the absorbance and conductivity of the uranyl acid solution to be tested, and perform temperature compensation on the conductivity of the uranyl acid solution to be tested;

[0056] The absorbance of the uranyl acid solution to be measured and the conductivity after temperature compensation are used according to the fitted surface equation to obtain the uranium concentration and acid concentration of the uranyl acid solution to be measured.

[0057] This embodiment provides an analysis device used in the above-mentioned real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured, comprising:

[0058] The detection module is used to measure the absorbance and conductivity of the prepared uranic acid solution, send the absorbance of the prepared uranic acid solution to the data integration module, and send the conductivity of the prepared uranic acid solution to the temperature compensation module. The detection module is also used to measure the absorbance and conductivity of the uranic acid solution to be measured, send the absorbance of the uranic acid solution to be measured to the calculation module, and send the conductivity of the uranic acid solution to be measured to the temperature compensation module;

[0059] The temperature compensation module is used to perform temperature compensation on the conductivity of the prepared uranyl acid solution, obtain the sample conductivity after temperature compensation, and send it to the data integration module. The temperature compensation module is also used to perform temperature compensation on the conductivity of the uranyl acid solution to be measured, obtain the sample conductivity after temperature compensation, and send it to the calculation module;

[0060] A data integration module is used to establish a database with the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, integrate the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array, and send the array to the fitting module;

[0061] The fitting module is used to perform surface fitting based on MATLAB on the data in the array integrated by the data integration module, taking uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation;

[0062] The calculation module is used to obtain the uranium concentration and acid concentration of the uranium acid solution to be measured according to the fitted surface equation by using the absorbance of the uranium acid solution to be measured and the conductivity after temperature compensation obtained by the detection module.

[0063] The beneficial effects of the real-time analysis method and device for uranium and acid concentration in the uranium acid solution to be measured in this embodiment are as follows:

[0064] (1) This method can be directly used for real-time monitoring of uranium concentration and acid concentration in the uranium dissolution tank of the post-processing process. This method does not require sampling and analysis and can maintain long-term stability and reliability;

[0065] (2) The device overcomes the influence of temperature and uranium acid mixture system on the measurement results of uranium concentration and acid concentration;

[0066] (3) Compared with the single measurement method for determining the uranium concentration and acid concentration in the solution, the error of the device is smaller and the acid concentration and uranium concentration data obtained are more accurate.

[0067] Example 2

[0068] like Figure 1 As shown, this embodiment provides a real-time analysis method for the concentration of uranium and acid in a uranium acid solution to be measured, comprising the following steps:

[0069] S201 measures the absorbance and conductivity of the prepared uranyl acid solution, performs temperature compensation on the conductivity of the prepared uranyl acid solution, and obtains the conductivity of the sample after temperature compensation;

[0070] S202 establishes a parameter database of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, and integrates the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array;

[0071] S203 performs surface fitting on the data in the integrated array based on MATLAB, taking uranium concentration and acid concentration as dependent variables and absorbance and conductivity as independent variables, to obtain a fitted surface equation;

[0072] S204 measures the absorbance and conductivity of the uranyl acid solution to be tested, and performs temperature compensation on the conductivity of the uranyl acid solution to be tested;

[0073] S205 obtains the uranium concentration and acid concentration of the uranium acid solution to be measured by using the absorbance of the uranium acid solution to be measured and the conductivity after temperature compensation according to the fitted surface equation.

[0074] Preferably, the fitted surface equation is:

[0075] U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY (1);

[0076] H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 - 34.56X 2 Y-126.2XY 2 -12.96Y3 +58.97X 2 Y 2 +77.04XY 3 +3.606Y 4 (2)

[0077] Where X is the absorbance of the uranyl acid solution, Y is the conductivity after temperature compensation, U is the uranium concentration, and H is the hydrogen ion concentration in the acid.

[0078] Preferably, the correlation coefficient of the fitted surface equation is in the range of 0.99-1.

[0079] Preferably, the uranium-containing group in the uranium acid solution to be detected is a uranyl group.

[0080] Specifically, the acid of the uranyl acid solution to be tested in this embodiment is nitric acid. The uranyl acid solution in this embodiment contains uranyl nitrate. Of course, the uranyl acid solution to be tested may contain fluorine ions, chloride ions, iron ions, americium ions, and chromium ion impurities.

[0081] Preferably, the temperature compensation formula is:

[0082]

[0083] Where ρ is the conductivity, t is the temperature, β1 is the first temperature coefficient, β2 is the second temperature coefficient, ρ T is the conductivity at the compensation temperature, and T is the compensation temperature.

[0084] Preferably, the uranium concentration of the uranium acid solution to be tested is 30 g / L to 350 g / L, and the hydrogen ion concentration in the acid is 0.1 mol / L to 6 mol / L.

[0085] like Figure 2 , 3 This embodiment provides an analysis device used in the above-mentioned real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured, comprising:

[0086] The detection module is used to measure the absorbance and conductivity of the prepared uranic acid solution, send the absorbance of the prepared uranic acid solution to the data integration module, and send the conductivity of the prepared uranic acid solution to the temperature compensation module. The detection module is also used to measure the absorbance and conductivity of the uranic acid solution to be measured, send the absorbance of the uranic acid solution to be measured to the calculation module, and send the conductivity of the uranic acid solution to be measured to the temperature compensation module;

[0087] The temperature compensation module is used to perform temperature compensation on the conductivity of the prepared uranyl acid solution, obtain the sample conductivity after temperature compensation, and send it to the data integration module. The temperature compensation module is also used to perform temperature compensation on the conductivity of the uranyl acid solution to be measured, obtain the sample conductivity after temperature compensation, and send it to the calculation module;

[0088] A data integration module is used to establish a database with the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, integrate the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array, and send the array to the fitting module;

[0089] The fitting module is used to perform surface fitting based on MATLAB on the data in the array integrated by the data integration module, taking uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation;

[0090] The calculation module is used to obtain the uranium concentration and acid concentration of the uranium acid solution to be measured according to the fitted surface equation by using the absorbance of the uranium acid solution to be measured and the conductivity after temperature compensation obtained by the detection module.

[0091] Preferably, the detection module comprises:

[0092] The first detection module is used to measure the absorbance of the prepared uranic acid solution and the absorbance of the uranic acid solution to be tested respectively, send the absorbance of the prepared uranic acid solution to the data integration module, and send the absorbance of the uranic acid solution to be tested to the calculation module;

[0093] The second detection module is used to measure the conductivity of the prepared uranyl acid solution and the conductivity of the uranyl acid solution to be measured respectively, and send the conductivity of the prepared uranyl acid solution and the conductivity of the uranyl acid solution to be measured to the temperature compensation module.

[0094] Preferably, the fitted surface equation is:

[0095] U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY (1);

[0096] H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 - 34.56X 2 Y-126.2XY 2 -12.96Y 3 +58.97X 2 Y 2 +77.04XY 3 +3.606Y 4 (2)

[0097] Where X is the absorbance of the uranyl acid solution, Y is the conductivity after temperature compensation, U is the uranium concentration, and H is the hydrogen ion concentration in the acid.

[0098] Specifically, the first detection module in this embodiment includes an acid concentration probe 2 and an acid signal transmitter 3 connected to the acid concentration probe 2, and the acid concentration probe 2 sends a signal to the data integration module through the acid signal transmitter 3. The second detection module includes a uranium concentration probe 1 and a uranium signal transmitter 4 connected to the uranium concentration probe 1, and the uranium concentration probe 1 sends a signal to the data integration module through the uranium signal transmitter 4. The analysis device in this embodiment is a U-HNO3 real-time monitor, which also includes: a control panel 5, a mounting flange 6, a connecting cable 7 and other supporting and fixing components.

[0099] The device has a simple interface connection with the uranium dissolution tank 28. The uranium concentration probe 1, the acid concentration probe 2 and the mounting flange 6 are designed to be integrated. The mounting flange 6 is a DN150 flange. The mounting flange 6 is provided with a uranium concentration probe access port 24 and an acid concentration probe access port 25. The mounting flange 6 is fixed by an M12 fixing bolt 26. The uranium concentration probe 1, the acid concentration probe 2 and the uranium dissolution tank 28 can be installed through the DN150 flange. The cable is connected to the control panel 5. The cable is also connected to the acid signal transmitter 3 and the uranium signal transmitter 4 respectively. The cable is a radiation-resistant cable. The measurement signal is transmitted to the control panel 5 in the green zone room through the radiation-resistant cable to ensure that the operator is subjected to the minimum radiation dose. At the same time, the control panel 5 has the functions of signal remote transmission and over-limit alarm.

[0100] like Figure 4 As shown, the uranium concentration probe 1 of the device is arranged vertically. The uranium concentration probe 1 includes a radiation source 8, a detector, and a lead tank 9. The lead tank 9 is arranged outside the radiation source 8. The solution 10 to be tested is placed between the radiation source 8 and the detector. The container shell containing the solution 10 to be tested is provided with a lead shielding layer 27. An observation channel 11 is provided on the lead tank 9. A collimation hole 12 is provided between the radiation source 8 and the detector for observation. The collimation hole 12 passes through the observation channel 11. The radiation source 8 is 30mCi 241 Am source, the detector is a sodium iodide crystal detector, there is no lead shielding layer at the connection between the container for holding the solution 10 to be tested and the collimation hole 12 and the sodium iodide crystal 14, the sodium iodide crystal detector includes a photomultiplier tube 13, a sodium iodide crystal 14 arranged at the detection end of the photomultiplier tube 13, a detection circuit 15 connected to the photomultiplier tube 13, and a terminal 16 connected to the detection circuit 15. The outside of the radiation source 8 is a 4mm lead can 9 to ensure the shielding requirements, the probe support part is a hole structure, the probe size is Φ65, and the top of the radiation source 8 adopts a conical design to ensure good fluidity of the probe.

[0101] like Figure 5As shown, the acid concentration probe 2 of the device adopts an electromagnetic sensor probe, and the acid concentration probe 2 includes a conductivity measurement coil and a conductivity measurement coil temperature sensitive element connected to the conductivity measurement coil. The conductivity measurement coil and the temperature sensitive element are designed in an integrated manner to ensure the miniaturization and sensitivity of the probe. The size of the acid concentration probe 2 is Φ60, and the thickness of the measurement center inner hole 21 of the probe is 40mm, and it is designed to be in a vertical direction, which can effectively prevent the accumulation of solids in the measured solution from clogging the measurement center inner hole 21 and affecting its normal measurement function. The shells of the uranium concentration probe 1 and the acid concentration probe 2 are both made of polyvinylidene fluoride (PVDF) material, which has excellent chemical stability, corrosion resistance, high temperature resistance, radiation resistance, easy sealing of key measurement components, anti-scaling and good anti-aging ability.

[0102] Preferably, the temperature compensation formula is:

[0103]

[0104] Where ρ is the conductivity, t is the temperature, β1 is the first temperature coefficient, β2 is the second temperature coefficient, ρ T is the conductivity at the compensation temperature, and T is the compensation temperature.

[0105] Specifically, the device in this embodiment measures the absorbance of the uranyl acid solution based on the gamma-ray absorption method, and measures the conductivity of the uranyl acid solution based on the electrodeless conductivity method. Electrodeless conductivity method: Since the nitric acid concentration in the measured uranyl acid solution is relatively high, the solution conductivity is relatively large, and the solution conductivity measurement adopts an electromagnetic sensor probe, which uses the electromagnetic induction method to measure the solution conductivity. Because the induction element is not directly in contact with the measured solution, it is called the electrodeless conductivity method.

[0106] The device in this embodiment is designed by combining the gamma-ray absorption method and the conductivity method. By measuring the conductivity and gamma-ray transmission intensity of prepared uranyl acid solutions of different concentrations, the influence law between conductivity, absorbance and uranium concentration and nitric acid concentration in the prepared uranyl acid solution is established. At the same time, the mutual compensation relationship between temperature, uranium concentration and nitric acid concentration is established, and the real-time analysis of uranium concentration and acid concentration under the conditions of uranium concentration in uranyl acid solution: 30g / L~350g / L, nitric acid concentration: 0.1mol / L~6mol / L, temperature: 0~80℃, ambient humidity: 20%~80%, and stirring speed: 0-150r / min is achieved.

[0107] Specifically, the analysis method in this embodiment is as follows:

[0108] First, the relationship between the conductivity and temperature of the prepared uranyl acid solution is studied and determined: in addition to the relationship between the conductivity of the solution and the acid concentration, the temperature change of the solution also has a great influence on its conductivity. The conductivity of the solution increases significantly with the increase of the solution temperature, which seriously affects the measurement of acidity by the conductivity method, and certain temperature compensation measures need to be taken. In this embodiment, a temperature compensation test was carried out, and 4 prepared uranyl acid solutions were selected for the temperature compensation test. The solution concentration and the conductivity of the solution at different temperatures are shown in Table 1 below. The table below lists the uranium concentration, acid concentration, corresponding conductivity at different temperatures in different uranyl acid solutions, and the corresponding first temperature coefficient β1 and second temperature coefficient β2.

[0109] Table 1

[0110]

[0111]

[0112] The solution conductivity temperature compensation is performed according to the following temperature compensation formula: In the formula, the average value of β1 is 1.00%, the average value of β2 is 0.0014%,

[0113]

[0114] (For the first group, the uranium concentration is 50g / L, the acid concentration is 0.5mol / L, ρ 40 =0.2114,ρ 27 =0.18)

[0115]

[0116] (For the first group, the uranium concentration is 50g / L, the acid concentration is 0.5mol / L, ρ 61 =0.266,ρ 70 =0.29)

[0117] Solving the equation system consisting of the above two equations, we can obtain β1 of 0.979% and β2 of 0.0014% for a uranium concentration of 50g / L and an acid concentration of 0.5mol / L. Similarly, other β1 and β2 data are obtained using the above calculation method.

[0118] For temperature compensation formula

[0119] When the compensation temperature T = 60°C, the temperature compensation formula is as follows:

[0120]

[0121] The study established the relationship between the conductivity and absorbance of uranyl acid solution: under laboratory conditions, the absorbance of the uranium concentration probe 1 and the conductivity of the acid concentration probe 2 at the current temperature were tested using the above-mentioned prepared uranyl acid solutions of different concentration combinations after manual analysis, and the conductivity was converted to the conductivity at 60°C according to the above-mentioned temperature compensation formula. Specific test data examples are shown in Table 2 below.

[0122] Table 2

[0123]

[0124] The study established the influence between the conductivity and absorbance of the prepared uranium acid solution and the uranium concentration in the prepared solution and the hydrogen ion concentration in the acid: Based on the data in the above two tables, the uranium concentration and the hydrogen ion concentration in the acid are used as dependent variables, the absorbance and conductivity are used as independent variables, and matlab is used to make the surface equation. Set X as the absorbance of the uranium acid solution, Y as the conductivity after temperature compensation, U as the uranium concentration, and H as the hydrogen ion concentration in the acid. The fitted surface equation is as follows:

[0125] U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY (1) Correlation coefficient R1 2 =0.999;

[0126] H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 - 34.56X 2 Y-126.2XY2-12.96Y 3 +58.97X 2 Y2+77.04XY 3 +3.606Y 4 (2)

[0127] Correlation coefficient R2 2 =0.998;

[0128] It can be seen from the above fitted surface equation that the correlation between the surface equation and the measured data is relatively ideal. According to the above fitted surface equation, combined with the above conductivity and absorbance, the uranium concentration and acid concentration are back-calculated, and the relative error is calculated, which is within 5%.

[0129] The absorbance of the uranyl acid solution to be measured and the conductivity after temperature compensation are used according to the fitted surface equation to obtain the uranium concentration and acid concentration of the uranyl acid solution to be measured.

[0130] like Figure 1As shown, the analysis device in this embodiment includes two measuring probes (uranium concentration probe 1, acid concentration probe 2) and two signal transmitters (acid signal transmitter 3, uranium signal transmitter 4) and a control panel 5. The connecting cable 7 connects the several components together with the mounting flange 6 and the supporting components to form a complete set of devices.

[0131] Uranium concentration measurement: The uranium concentration probe 1 is installed and fixed in the dissolution tank. During the uranium dissolution process, the dissolving liquid completely fills the measuring hole of the probe. The 241Am radiation source 8 emits 59.5keV gamma rays, which pass through the dissolving liquid and reach the NaI (Tl) crystal. The excited photons are converted into photoelectric signals and amplified by the photomultiplier tube 13, and the electrical signals are transmitted to the control panel 5 through the uranium signal transmitter. The analog front-end circuit of the control panel 5 converts the signal into a 0-2V voltage signal, and the voltage signal is converted into a digital signal by the A / D converter and sent to the single-chip microcomputer. The single-chip microcomputer performs digital filtering on the signal, nonlinear calibration and other operations, and then sends the concentration value to the D / A converter. The analog voltage signal output by the D / A converter is converted into a 4-20mA standard signal output by the V / I conversion circuit to display the uranium concentration measurement result.

[0132] Acid concentration measurement: The acid concentration probe 2 includes an excitation coil 17, a detection coil 18 and a temperature detector 19. The excitation coil 17, the detection coil 18 and the temperature detector 19 are all arranged in a polytetrafluoroethylene shell 20. The temperature detector 19 includes a temperature probe and a temperature measurement circuit. The excitation coil 17 and the detection coil 18 are both magnetic core rings wound with copper wire. The excitation coil 17 and the detection coil 18 are both arranged outside the measurement center inner hole 21. Therefore, when the dissolved liquid completely fills the measurement center inner hole 21 of the acid concentration probe 2, a conductivity inductance is formed. The conductivity signal output by the detection coil 18 passes through the acid signal transmitter, and then is transmitted to the control panel 5 through the signal lead-out line 22 connected thereto. A stainless steel support connecting tube 23 is arranged outside the signal transmission line. The analog front circuit of the control panel 5 converts the conductivity signal into a voltage signal, and the voltage signal is converted into a digital signal and sent to the single-chip microcomputer. The temperature compensation circuit converts the temperature signal into a digital signal. The single-chip microcomputer performs digital filtering, D / A conversion, and V / I conversion on the signal to output a 4-20mA standard signal to display the acid concentration measurement result.

[0133] The beneficial effects of the real-time analysis method and device for uranium and acid concentration in the uranium acid solution to be measured in this embodiment are as follows:

[0134] (1) This method can be directly used for real-time monitoring of uranium concentration and acid concentration in the uranium dissolving tank 28 of the post-processing process. This method does not require sampling and analysis and can maintain long-term stability and reliability. It is specifically used for real-time analysis of uranium concentration and acid concentration in the uranium dissolving tank 28 of the post-processing process under the condition that uranium and acid interfere with each other. It has the advantages of fast analysis speed, no need to consume samples, good radiation resistance, simple operation and maintenance, and long-distance transmission of measurement results.

[0135] (2) The device overcomes the influence of temperature and uranium acid mixture system on the measurement results of uranium concentration and acid concentration;

[0136] (3) Compared with the single measurement method for determining the uranium concentration and acid concentration in the solution, the error of the device is smaller and the acid concentration and uranium concentration data obtained are more accurate.

[0137] 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 real-time analysis method for the concentration of uranium and acid in a uranium acid solution to be measured, characterized in that: The following steps are involved: The absorbance and conductivity of the prepared uranyl acid solution are measured, and the conductivity of the prepared uranyl acid solution is temperature compensated to obtain the conductivity of the sample after temperature compensation; Establishing a parameter database of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, and integrating the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array; The data in the integrated array are respectively used for surface fitting based on MATLAB, with uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation; Measure the absorbance and conductivity of the uranyl acid solution to be tested, and perform temperature compensation on the conductivity of the uranyl acid solution to be tested; The absorbance of the uranyl acid solution to be measured and the conductivity after temperature compensation are used according to the fitted surface equation to obtain the uranium concentration and acid concentration of the uranyl acid solution to be measured.

2. The real-time analysis method for measuring the concentration of uranium and acid in a uranium acid solution to be measured according to claim 1, characterized in that: The fitted surface equation is: U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY(1) H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 -34.56X 2 Y-126.2XY 2 -12.96Y 3 +58.97X 2 Y 2 +77.04XY 3 +3.606Y 4 (2) Where X is the absorbance of the uranic acid solution, Y is the conductivity after temperature compensation, U is the uranium concentration, and H is the hydrogen ion concentration in the acid.

3. The real-time analysis method for measuring the concentration of uranium and acid in a uranium acid solution to be measured according to claim 1, characterized in that: The correlation coefficients of the fitted surface equations range from 0.99 to 1.

4. The real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured according to claim 1, characterized in that: The group containing uranium in the uranyl acid solution to be tested is a uranyl group.

5. The real-time analysis method for measuring the concentration of uranium and acid in a uranium acid solution to be measured according to claim 1, characterized in that: The formula used for the temperature compensation is: Where ρ is the conductivity, t is the temperature, β1 is the first temperature coefficient, β2 is the second temperature coefficient, ρ T is the conductivity at the compensation temperature, and T is the compensation temperature.

6. The real-time analysis method for measuring the concentration of uranium and acid in a uranium acid solution to be measured according to claim 1, characterized in that: The uranium concentration of the uranium acid solution to be tested is 30 g / L to 350 g / L, the hydrogen ion concentration in the acid is 0.1 mol / L to 6 mol / L, the temperature is 0 to 80° C., and the environmental humidity is 20% to 80%.

7. An analysis device for use in a real-time analysis method for uranium and acid concentrations in a uranium acid solution to be measured according to any one of claims 1 to 6, characterized in that: include: The detection module is used to measure the absorbance and conductivity of the prepared uranic acid solution, send the absorbance of the prepared uranic acid solution to the data integration module, and send the conductivity of the prepared uranic acid solution to the temperature compensation module. The detection module is also used to measure the absorbance and conductivity of the uranic acid solution to be measured, send the absorbance of the uranic acid solution to be measured to the calculation module, and send the conductivity of the uranic acid solution to be measured to the temperature compensation module; The temperature compensation module is used to perform temperature compensation on the conductivity of the prepared uranyl acid solution, obtain the sample conductivity after temperature compensation, and send it to the data integration module. The temperature compensation module is also used to perform temperature compensation on the conductivity of the uranyl acid solution to be measured, obtain the sample conductivity after temperature compensation, and send it to the calculation module; A data integration module is used to establish a database with the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution, integrate the parameters of uranium concentration, acid concentration, absorbance, and sample conductivity after temperature compensation for preparing uranyl acid solution into an array, and send the array to the fitting module; The fitting module is used to perform surface fitting based on MATLAB on the data in the array integrated by the data integration module, taking uranium concentration and acid concentration as dependent variables, and absorbance and conductivity as independent variables, to obtain the fitted surface equation; The calculation module is used to obtain the uranium concentration and acid concentration of the uranium acid solution to be measured according to the fitted surface equation by using the absorbance of the uranium acid solution to be measured and the conductivity after temperature compensation obtained by the detection module.

8. The analysis device used in the real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured according to claim 7, characterized in that: The detection module comprises: The first detection module is used to measure the absorbance of the prepared uranic acid solution and the absorbance of the uranic acid solution to be tested respectively, send the absorbance of the prepared uranic acid solution to the data integration module, and send the absorbance of the uranic acid solution to be tested to the calculation module; The second detection module is used to measure the conductivity of the prepared uranyl acid solution and the conductivity of the uranyl acid solution to be measured respectively, and send the conductivity of the prepared uranyl acid solution and the conductivity of the uranyl acid solution to be measured to the temperature compensation module.

9. The analysis device used in the real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured according to claim 7, characterized in that: The fitted surface equation is: U=-14.22+590.1X-0.5419Y-174.3X 2 -20.51XY(1); H=0.7723-9.414X-3.912Y+6.151X 2 +61XY+15.23Y 2 -34.56X 2 Y-126.2XY 2 -12.96Y 3 +58.97X 2 Y 2 +77.04XY 3 +3.606Y 4 (2), Where X is the absorbance of the uranic acid solution, Y is the conductivity after temperature compensation, U is the uranium concentration, and H is the hydrogen ion concentration in the acid.

10. The analysis device used in the real-time analysis method for the concentration of uranium and acid in the uranium acid solution to be measured according to claim 7, characterized in that: The formula used for the temperature compensation is: Where ρ is the conductivity, t is the temperature, β1 is the first temperature coefficient, β2 is the second temperature coefficient, ρ T is the conductivity at the compensation temperature, and T is the compensation temperature.

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