Method for measuring water content in a radioactive suspension

Abstract

The present invention provides a method for determining the water content in a radioactive suspension, comprising: taking the radioactive suspension and determining the mass of the radioactive suspension; adding the radioactive suspension to a Karl Fischer reagent, causing the water in the radioactive suspension to react with the Karl Fischer reagent and oxidizing iodine to iodide ions, wherein the Karl Fischer reagent at least comprises: iodine, sulfur dioxide, and pyridine; subjecting the iodide ions to electrolytic treatment to reduce the iodide ions to iodine and obtaining the amount of electricity consumed when reducing the iodide ions; and calculating the water content in the radioactive suspension according to the mass of the radioactive suspension and the amount of electricity consumed when reducing the iodide ions. The solution of the present invention can quickly and accurately determine the water content in the radioactive suspension.

Description

Technical Field

[0001] The present invention relates to the technical field of spent fuel reprocessing analysis, and particularly to a method for determining the water content in a radioactive suspension. Background Art

[0002] Rectification residue will be generated in the spent fuel reprocessing process. The rectification residue usually contains tributyl phosphate, kerosene and other radiation degradation products. To treat the above rectification residue, it is often formulated into a radioactive suspension for pyrolysis incineration volume reduction treatment.

[0003] Among them, the radioactive suspension contains a certain amount of water. The water helps to adjust the system viscosity, improve the stability and uniformity of the radioactive suspension, and promote the pyrolysis incineration volume reduction treatment. However, when the water content in the radioactive suspension is too high, it will increase the heat load of the pyrolysis furnace. Therefore, in order to ensure that the water content in the radioactive suspension is within an appropriate range to ensure the smooth progress of the process flow and operate at a lower cost, it is necessary to measure and analyze the water content in the radioactive suspension.

[0004] At present, there are many methods for measuring the water content. Commonly used methods for measuring the water content include distillation method, gravimetric method, microwave method, infrared absorption spectrometry, etc. However, due to the special composition of the radioactive suspension, the above methods are not applicable to the determination of the water content in the radioactive suspension, and the measurement results cannot be obtained quickly and accurately. Summary of the Invention

[0005] The present invention provides a method for determining the water content in a radioactive suspension to solve the problem that the existing methods for measuring the water content cannot quickly and accurately measure the water content in the radioactive suspension.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A method for determining the water content in a radioactive suspension, comprising:

[0008] (1) Take a radioactive suspension and determine the mass of the radioactive suspension;

[0009] (2) Add the radioactive suspension to the Karl Fischer reagent, so that the water in the radioactive suspension reacts with the Karl Fischer reagent, and oxidize iodine to iodide ion. Among them, the Karl Fischer reagent at least includes: iodine, sulfur dioxide, pyridine;

[0010] (3) Electrolyze the iodide ion obtained in step (2) to reduce the iodide ion to iodine, and obtain the amount of electricity consumed when reducing the iodide ion;

[0011] (4) Calculate the water content in the radioactive suspension based on the mass of the radioactive suspension obtained in step (1) and the amount of electricity consumed in reducing iodide ions in step (3).

[0012] Optionally, in step (1), the mass of the radioactive suspension is determined by the following method:

[0013] Take a container, determine the mass of the container, then place the radioactive suspension in the container and determine the total mass of the container and the radioactive suspension; then, subtract the mass of the container from the total mass to obtain the mass of the radioactive suspension.

[0014] Optionally, in step (3), the electrolysis current for the electrolysis treatment is 0 to 300 milliamperes.

[0015] Optionally, in step (4), the water content in the radioactive suspension is the water content obtained after rounding.

[0016] Optionally, in step (2), first dilute and mix the radioactive suspension with ethanol, and then add the Karl Fischer reagent.

[0017] Optionally, step (2) further includes: centrifuging the radioactive suspension after diluting and mixing it with ethanol, and taking the supernatant.

[0018] Optionally, the method for measuring the water content in the radioactive suspension further includes:

[0019] (a) Take the ethanol and determine the mass of the ethanol;

[0020] (b) Add the ethanol to the Karl Fischer reagent so that the water in the ethanol reacts with the Karl Fischer reagent and oxidizes iodine to iodide ions, where the Karl Fischer reagent at least includes: iodine, sulfur dioxide, pyridine;

[0021] (c) Electrolyze the iodide ions obtained in step (b) to reduce the iodide ions to iodine and obtain the amount of electricity consumed when reducing the iodide ions;

[0022] (d) Calculate the water content in the ethanol based on the mass of the ethanol obtained in step (a) and the amount of electricity consumed in reducing the iodide ions obtained in step (c).

[0023] Optionally, in step (4), the water content in the radioactive suspension is calculated by the following method:

[0024]

[0025] Wherein, ω is the water content in the radioactive suspension; m2 is the sum of the masses of the radioactive suspension, ethanol, and the container; m0 is the mass of the container; ω1 is the water content in the radioactive suspension after dilution and mixing with ethanol; m1 is the sum of the masses of the radioactive suspension and the container; ω EtOH is the water content in the ethanol obtained in step (d).

[0026] Optionally, the water content in the radioactive suspension after dilution and mixing with ethanol is calculated by the following method:

[0027] ω1 = Q / 10.722

[0028] Wherein, the ω1 is the water content in the radioactive suspension after dilution and mixing with ethanol; Q is the electricity consumption for reducing iodide ions obtained in step (3).

[0029] Optionally, the water content of the ethanol is calculated by the following method:

[0030] ω EtOH = Q' / 10.722

[0031] Wherein, the ω EtOH is the water content in the ethanol, and Q' is the electricity consumption for reducing iodide ions obtained in step (c).

[0032] The above solution of the present invention has at least the following beneficial effects:

[0033] The method for measuring the water content in the radioactive suspension of the present invention includes: taking the radioactive suspension and determining the mass of the radioactive suspension; adding the radioactive suspension to the Karl Fischer reagent to react the water in the radioactive suspension with the Karl Fischer reagent and oxidize iodine to iodide ions, wherein the Karl Fischer reagent at least includes: iodine, sulfur dioxide, pyridine; electrolyzing the iodide ions to reduce the iodide ions to iodine and obtaining the electricity consumption for reducing iodide ions; calculating the water content in the radioactive suspension according to the mass of the radioactive suspension and the electricity consumption for reducing iodide ions. The method for measuring the water content in the radioactive suspension can quickly and accurately measure the water content in the radioactive suspension. Specific Embodiments

[0034] In the embodiments of the present invention, those not specified in specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase. Raw materials from different manufacturers and models do not affect the implementation of the technical solution of the present invention and the realization of the technical effect.

[0035] Example 1

[0036] The method for measuring the water content in the radioactive suspension of this embodiment includes the following steps:

[0037] (1) Take the radioactive suspension and determine the mass of the radioactive suspension.

[0038] Among them, the radioactive suspension mainly may include: tributyl phosphate, or kerosene and other radiation degradation products.

[0039] Specifically, the mass of the radioactive suspension can be determined by the following method:

[0040] Take a container, determine the mass of the container, then place the radioactive suspension in the container, and determine the total mass of the container and the radioactive suspension; then, subtract the mass of the container from the total mass to obtain the mass of the radioactive suspension.

[0041] (2) After diluting and mixing the radioactive suspension with ethanol, centrifuge the radioactive suspension and take the supernatant of the radioactive suspension; here, a centrifuge can be used to centrifuge the radioactive suspension, and then a syringe is used to suck the supernatant; among them, the dilution multiple of the radioactive suspension diluted with ethanol can be: 20 - 100 times; the centrifugation rate for centrifuging the radioactive suspension is: 4000 r / min (4000 revolutions per minute); the centrifugation time is: 5 minutes. Diluting, mixing and then centrifuging the radioactive suspension with ethanol is convenient for analyzing and processing the radioactive suspension, which can greatly shorten the time for processing and analysis and improve the accuracy of the analysis results at the same time.

[0042] Add the supernatant of the radioactive suspension to the Karl Fischer reagent, so that the water in the radioactive suspension reacts with the Karl Fischer reagent and oxidizes iodine to iodide ions, where the Karl Fischer reagent at least includes: iodine, sulfur dioxide, pyridine.

[0043] (3) Electrolyze the iodide ions obtained in step (2) to reduce the iodide ions to iodine and obtain the amount of electricity consumed when reducing the iodide ions.

[0044] Among them, the electrolysis current for the electrolysis treatment is 50 milliamperes.

[0045] (4) Calculate the water content in the radioactive suspension according to the mass of the radioactive suspension obtained in step (1) and the amount of electricity consumed when reducing the iodide ions obtained in step (3). Among them, the water content in the radioactive suspension is the water content obtained after rounding treatment.

[0046] It should be noted that the supernatant of the radioactive suspension is added to the Karl Fischer reagent, so that the water in the radioactive suspension reacts with substances such as iodine, sulfur dioxide, and pyridine in the Karl Fischer reagent to produce pyridine hydroiodide and pyridine methyl sulfate, and oxidize iodine to iodide ions. The consumed iodine is electrolyzed at the anode, so that the redox reaction proceeds continuously until all the water is exhausted. The reaction formula of the above reaction process is as follows:

[0047] H2O+I2+SO2+3C5H5N→2C5H5N·HI+C5H5N·SO3

[0048] 2I - -2e→I2

[0049] According to Faraday's law of electrolysis, the amount of iodine electrolyzed is proportional to the amount of electricity consumed when reducing iodide ions. Therefore, the water content in the radioactive suspension can be calculated based on the amount of electricity consumed when reducing iodide ions.

[0050] As a specific implementation manner of this embodiment, the water content in the radioactive suspension is calculated by the following method:

[0051]

[0052] where ω is the water content in the radioactive suspension; m2 is the sum of the masses of the radioactive suspension, ethanol, and the container; m0 is the mass of the container; ω1 is the water content in the radioactive suspension diluted and mixed with ethanol; m1 is the sum of the masses of the radioactive suspension and the container; ω EtOH is the water content in the ethanol obtained in step (d).

[0053] It should be noted that the water content in the radioactive suspension is the average value calculated by repeating the calculation step (4) twice and rounding the calculation results of the two times respectively. The calculation result can be retained to three decimal places.

[0054] The water content in the radioactive suspension diluted and mixed with ethanol is calculated by the following method:

[0055] ω1=Q / 10.722

[0056] where ω1 is the water content in the radioactive suspension diluted and mixed with ethanol; Q is the amount of electricity consumed when reducing iodide ions obtained in step (3).

[0057] The water content ω of the ethanol EtOH , is obtained by the following method:

[0058] (a) Take the ethanol and determine the mass of the ethanol;

[0059] (b) Add the ethanol to the Karl Fischer reagent, causing the water in the ethanol to react with the Karl Fischer reagent and oxidize iodine to iodide ions. Among them, the Karl Fischer reagent at least includes: iodine, sulfur dioxide, and pyridine;

[0060] (c) Electrolyze the iodide ions obtained in step (b) to reduce the iodide ions to iodine and obtain the amount of electricity consumed when reducing the iodide ions;

[0061] (d) Calculate the water content in the ethanol based on the mass of the ethanol obtained in step (a) and the amount of electricity consumed when reducing the iodide ions obtained in step (c).

[0062] The water content of the ethanol is calculated by the following method:

[0063] ω EtOH = Q’ / 10.722

[0064] Among them, the ω EtOH is the water content in the ethanol, and Q’ is the amount of electricity consumed when reducing the iodide ions obtained in step (c).

[0065] In this embodiment, the sum of the masses of the calculated radioactive suspension and ethanol (m2 - m0) is multiplied by the measured water content ω1 in the radioactive suspension after dilution and mixing with ethanol, and then the mass of ethanol (m2 - m1) multiplied by the measured water content ω of ethanol is subtracted. EtOH , and then divided by the mass of the radioactive suspension (m1 - m0), and multiplied by one hundred percent to obtain the water content ω in the radioactive suspension;

[0066] Then, by repeating step (4) twice and performing rounding processing on the calculation results of the two times respectively, and calculating the average value from the water content values of the radioactive suspension obtained from the two calculation results, the accurate water content in the radioactive suspension can be obtained.

[0067] Comparative Example 1

[0068] The method for measuring the water content in the radioactive suspension of this comparative example is only different from that of Example 1 in that: in step (2), the following steps are omitted: after diluting and mixing the radioactive suspension with ethanol, centrifuging the radioactive suspension and taking the supernatant of the radioactive suspension. That is, directly add the radioactive suspension to the Karl Fischer reagent, causing the water in the radioactive suspension to react with the Karl Fischer reagent and oxidize iodine to iodide ions.

[0069] Effect Test Example

[0070] To verify the technical effect of the method for measuring the water content in the radioactive suspension of the present invention, the following experiment is carried out:

[0071] The same batch of radioactive suspension was measured according to the method for measuring the water content in the radioactive suspension in Example 1, and a total of three groups were measured. Among them, when the first group was measured, in step (2), the volume ratio of the radioactive suspension to 99.0 wt% ethanol used for dilution was 1:20, and the measurement result of this group was recorded as the first group; when the second group was measured, in step (2), the volume ratio of the radioactive suspension to 99.0 wt% ethanol used for dilution was 1:60, and the measurement result of this group was recorded as the second group; when the third group was measured, in step (2), the volume ratio of the radioactive suspension to 99.0 wt% ethanol used for dilution was 1:100, and the measurement result of this group was recorded as the third group. The radioactive suspension of this batch was measured according to the method for measuring the water content in the radioactive suspension of Comparative Example 1, and the measurement result of this group was recorded as the fourth group. Each group was measured three times repeatedly, and the water content was recorded, where the water content refers to the percentage (%) of the mass of water in the total mass of the radioactive suspension.

[0072] The test results are as follows:

[0073]

[0074] According to the comparison, the dilution multiple of the radioactive suspension with ethanol has a certain influence on the measurement result of the water content ω1 in the radioactive suspension. Whether the test parameters include the water content ω in ethanol EtOH has a significant impact on the accuracy of the water content in the radioactive suspension. When the volume ratio of the radioactive suspension to 99.0 wt% ethanol used for dilution is 1:60, the results of three parallel experiments fluctuate the least, and the test results have the best stability.

[0075] As is known by common technical knowledge, the present invention can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and are not the only ones. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. A method for measuring the water content in a radioactive suspension, characterized in that, Comprising: (1) Take a radioactive suspension and determine the mass of the radioactive suspension; The radioactive suspension includes: tributyl phosphate, or kerosene and other radiation degradation products; the mass of the radioactive suspension is determined by the following method: Take a container, determine the mass of the container, then place the radioactive suspension in the container, and determine the total mass of the container and the radioactive suspension; then, subtract the mass of the container from the total mass to obtain the mass of the radioactive suspension; (2) After diluting and mixing the radioactive suspension with ethanol, centrifuge the radioactive suspension and take the supernatant of the radioactive suspension. The dilution ratio of the radioactive suspension to ethanol is 20 - 100 times; add the supernatant of the radioactive suspension to the Karl Fischer reagent to cause the water in the radioactive suspension to react with the Karl Fischer reagent and oxidize iodine to iodide ions. Among them, the Karl Fischer reagent at least includes: iodine, sulfur dioxide, pyridine; (3) Electrolyze the iodide ions obtained in step (2) to reduce the iodide ions to iodine and obtain the amount of electricity consumed when reducing the iodide ions; (4) Calculate the water content in the radioactive suspension according to the mass of the radioactive suspension obtained in step (1) and the amount of electricity consumed when reducing the iodide ions obtained in step (3); The water content in the radioactive suspension is calculated by the following method: Where ω is the water content in the radioactive suspension; m2 is the sum of the masses of the radioactive suspension, ethanol, and the container; m0 is the mass of the container; ω1 is the water content in the radioactive suspension after dilution and mixing with ethanol; m1 is the sum of the masses of the radioactive suspension and the container; ω EtOH is the water content in the ethanol obtained in step (d); The water content in the radioactive suspension after dilution and mixing with ethanol is calculated by the following method: ω1 = Q / 10.722 Wherein, ω1 is the water content in the radioactive suspension after dilution and mixing with ethanol; Q is the amount of electricity consumed when reducing the iodide ions obtained in step (3); The water content ω in the ethanol EtOH is obtained by the following method: (a) Take the ethanol and determine the mass of the ethanol; (b) Add the ethanol to the Karl Fischer reagent to cause the water in the ethanol to react with the Karl Fischer reagent and oxidize iodine to iodide ions. Among them, the Karl Fischer reagent at least includes: iodine, sulfur dioxide, pyridine; (c) Electrolyze the iodide ions obtained in step (b) to reduce the iodide ions to iodine and obtain the amount of electricity consumed when reducing the iodide ions; (d) Calculate the water content in the ethanol according to the mass of the ethanol obtained in step (a) and the amount of electricity consumed when reducing the iodide ions obtained in step (c); The water content of the ethanol is calculated by the following method: ω EtOH = Q’ / 10.722 where ω EtOH is the water content in ethanol, and Q' is the electricity consumption for reducing iodide ions obtained in step (c).

2. The method for measuring the water content in the radioactive suspension according to claim 1, characterized in that In step (3), the electrolysis current of the electrolysis treatment is 0 - 300 mA.

3. The method for determining the water content in the radioactive suspension according to claim 1, characterized in that, In step (4), the water content in the radioactive suspension is the water content obtained after rounding treatment.

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