An analytical measurement method

Abstract

The embodiment of the present application provides an analysis measurement method for measuring the tritium concentration in a spent fuel dissolving solution, and the analysis measurement method comprises the following steps: diluting and distilling the spent fuel dissolving solution to obtain a distillation distillate; adding the distillation distillate into a tritium column for filtering to obtain a target solution; adding a liquid scintillation liquid into the target solution for mixing, and obtaining a measurement result through a liquid scintillation counter; and obtaining the tritium concentration according to the measurement result. The analysis method of the embodiment of the present application has high accuracy in measuring the tritium concentration in the spent fuel dissolving solution.

Description

Technical Field

[0001] This application relates to the field of spent fuel reprocessing and analysis technology, and in particular to an analytical measurement method. Background Technology

[0002] In traditional spent fuel reprocessing, spent fuel assemblies are sheared and then directly dissolved. During this shearing and dissolution process, the vast majority of tritium is transferred into the dissolution solution. Tritium cannot be treated through conventional waste systems, making it a major radionuclide emitted into the environment during nuclear power plants and nuclear fuel reprocessing. Because tritium's beta rays have a maximum energy of 18 keV and an average energy of 5.7 keV, while other radionuclides (such as...)... 41 Ar and 90 The high-energy radiation produced by tritium (Sr) exceeds the decay energy of tritium, making its detection and monitoring very difficult. Furthermore, analytical methods for measuring tritium concentration in spent fuel solvents in related technologies have low accuracy. Summary of the Invention

[0003] In view of this, the main objective of the embodiments of this application is to provide an analytical measurement method with high accuracy for measuring the tritium concentration in spent fuel solution.

[0004] To achieve the above objectives, the technical solution of this application embodiment is implemented as follows:

[0005] This application provides an analytical measurement method for measuring the tritium concentration in spent fuel dissolved liquid. The analytical measurement method includes the following steps:

[0006] The spent fuel solution is diluted and distilled to obtain a distillate.

[0007] The distillate was added to a tritium column and filtered to obtain the target solution;

[0008] The target solution is mixed with a liquid scintillation solution, and the measurement results are obtained using a liquid scintillation counter.

[0009] The tritium concentration is obtained based on the measurement results.

[0010] In one embodiment, the dilution of the spent fuel solution specifically includes:

[0011] The spent fuel solution is diluted by a preset factor, and the pH of the diluted spent fuel solution is adjusted to neutral to obtain the initial analytical solution.

[0012] The initial analytical solution is diluted to a first preset volume to obtain a first sample solution.

[0013] In one embodiment, diluting the initial analytical solution to a first preset volume to obtain a first sample solution specifically includes:

[0014] The initial analytical solution was diluted with deionized water.

[0015] In one embodiment, obtaining the distillate specifically includes:

[0016] The first sample solution is distilled by gentle boiling to obtain the distillate.

[0017] In one embodiment, the initial analytical feed solution is the supernatant of the solution after the pH of the spent fuel dissolution solution has been adjusted to neutral.

[0018] In one embodiment, the tritium column comprises at least one of a cation exchange resin, an anion exchange resin, and an organic impurity adsorption resin.

[0019] In one embodiment, adding the distillate to a tritium column for filtration specifically includes:

[0020] The distillate was added to a tritium column in multiple batches for filtration.

[0021] In one embodiment, the step of adding the distillate to a tritium column for filtration to obtain the target solution specifically includes:

[0022] The tritium column has an inlet at the top and an outlet at the bottom. The distillate enters the tritium column through the inlet, is filtered, and then flows out through the outlet.

[0023] Discard the first portion of the second preset volume of effluent filtered through the tritium column, and collect the remaining portion of the effluent filtered through the tritium column as the target solution.

[0024] In one embodiment, adding a liquid scintillation solution to the target solution for mixing and obtaining the measurement results using a liquid scintillation counter specifically includes:

[0025] The volume of the target solution mixed with the liquid scintillation liquid is adjusted according to the measurement results so that the reading of the liquid scintillation counter is within a preset range.

[0026] In one embodiment, the reading of the liquid scintillation counter is greater than or equal to 100 and less than or equal to 100,000.

[0027] This application provides an analytical measurement method for measuring the tritium concentration in spent fuel dissolved liquid. The method includes the following steps: diluting and distilling the spent fuel dissolved liquid to obtain a distillate; adding the distillate to a tritium column for filtration to obtain a target solution; adding a liquid scintillation solution to the target solution for mixing, and obtaining the measurement result using a liquid scintillation counter; and obtaining the tritium concentration based on the measurement result. Therefore, on the one hand, the dilution and distillation steps can initially remove most interfering ions and impurities without adding multiple chemical reagents, simplifying the equipment and operation process. On the other hand, the further filtration by the tritium column can effectively remove residual ionic and organic impurities in the distillate, reducing the interference of these impurities on the tritium concentration measurement, thereby further improving the accuracy of the tritium concentration measurement. Attached Figure Description

[0028] Figure 1 This is a flowchart of an analytical measurement method according to an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of a distillation apparatus according to another embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of a tritium column according to another embodiment of this application.

[0031] Explanation of reference numerals in the attached figures

[0032] 10. Round-bottom flask; 11. Fractionating head; 12. Ground glass thermometer; 13. Condenser; 14. Vacuum receiving tube; 15. Ground glass conical flask; 16. Heater; 17. Iron stand; 18. Four-jaw clamp; 20. Tritium column; 21. Cation exchange resin; 22. Anion exchange resin; 23. Organic impurity adsorption resin. Detailed Implementation

[0033] Currently, the main instruments used for tritium detection or monitoring include ionization chambers, proportional counters, and liquid scintillation counters. Among them, gas-flow ionization chambers and proportional counters are used for continuous tritium monitoring in nuclear facilities, chimneys, and process monitoring.

[0034] In related technologies, the analysis of tritium in reactor decommissioning waste involves collecting tritium water through high-temperature desorption with humidification, followed by measurement using a liquid scintillation counter.

[0035] In related technologies, HTO is extracted from the soil and plants surrounding decommissioned facilities using a freeze-drying vacuum system equipped with a trap, and then measured using a liquid scintillation counter.

[0036] In related technologies, tissue free water tritium (TFWT) in plant samples around nuclear facilities is processed using a low-temperature analysis method, and then the tritium content in the plant samples around nuclear facilities is detected using a liquid scintillation counter.

[0037] In related technologies, for the analysis of tritium in drinking water or environmental water, tritium can be enriched by electrolytic concentration and then measured using a liquid scintillation counter.

[0038] In related technologies, the determination of tritium in spent fuel reprocessing solutions involves distilling the sample and then measuring the tritium using a liquid scintillation counter. However, this distillation method is complex and requires various chemical reagents such as AgNO3, HNO3, and NaOH, making the operation complicated.

[0039] Because spent fuel reprocessing solutions contain many interfering ions (such as U, Sr, Cs, Zr, etc.), and these elements are present in high concentrations and have high radioactivity, a high degree of purification is required. Methods such as humidification and high-temperature desorption, freeze-drying, low-temperature desorption, and electrolytic concentration are not suitable for processing these samples and cannot eliminate the influence of interfering ions.

[0040] One embodiment of this application provides an analytical measurement method for measuring the tritium concentration in spent fuel dissolved liquid. Please refer to [link to relevant documentation]. Figures 1 to 3 The analytical measurement method includes the following steps:

[0041] S1: Dilute and distill the spent fuel solution to obtain distillate.

[0042] S2: Add the distillate to a tritium column 20 for filtration to obtain the target solution.

[0043] S3: Add liquid scintillation liquid to the target solution for mixing, and obtain the measurement results through a liquid scintillation counter.

[0044] S4: Obtain the tritium concentration based on the measurement results.

[0045] Specifically, spent fuel dissolution fluid refers to the solution obtained after dissolving spent fuel, which contains various elements and radioactive materials.

[0046] Distillate refers to the solution obtained by evaporating the low-boiling-point components and then condensing the evaporated components, taking advantage of the different boiling points of the components in the spent fuel solution.

[0047] The tritium column 20 refers to the component used for filtering the distillate.

[0048] The structure of the tritium column 20 is not limited, as long as it can filter impurities in the distillate.

[0049] For example, the tritium column 20 includes at least one of a cation exchange resin 21, an anion exchange resin 22, and an organic impurity adsorption resin 23. This effectively filters impurities in the distillate, thereby improving the accuracy of tritium concentration measurement.

[0050] Specifically, the tritium column 20 may include only one of the cation exchange resin 21, anion exchange resin 22, and organic impurity adsorption resin 23, or it may include two of the cation exchange resin 21, anion exchange resin 22, and organic impurity adsorption resin 23 (for example, simultaneously including cation exchange resin 21 and anion exchange resin 22, or cation exchange resin 21 and organic impurity adsorption resin 23, or anion exchange resin 22 and organic impurity adsorption resin 23), or it may simultaneously include cation exchange resin 21, anion exchange resin 22, and organic impurity adsorption resin 23.

[0051] Liquid scintillation solution refers to a solution used for liquid scintillation measurements, which includes organic solvents and solutes (such as scintillators). During the measurement process, when the radiation generated by the decay of a radioactive nuclide (such as tritium) in the sample interacts with the liquid scintillation solution, the scintillator absorbs the radiation energy and emits photons. These photons can be detected by a liquid scintillation counter, thereby enabling the measurement of the radioactive nuclide.

[0052] A liquid scintillation counter is an instrument used to detect radioactive nuclides. It detects photon signals generated by the decay of radioactive nuclides in a liquid scintillation liquid, converts them into electrical signals for analysis, and thus determines the content of radioactive nuclides in a sample.

[0053] The analytical measurement method of this application embodiment is used to measure the tritium concentration in spent fuel dissolved liquid. The analytical measurement method includes the following steps: diluting and distilling the spent fuel dissolved liquid to obtain a distillate; adding the distillate to a tritium column 20 for filtration to obtain a target solution; adding a liquid scintillation solution to the target solution for mixing, and obtaining the measurement result through a liquid scintillation counter; obtaining the tritium concentration based on the measurement result. Therefore, on the one hand, the dilution and distillation steps can initially remove most interfering ions and impurities without adding multiple chemical reagents, and the equipment and operation process are simple. On the other hand, the further filtration effect of the tritium column 20 can effectively remove residual ionic and organic impurities in the distillate, reducing the interference of these impurities on the tritium concentration measurement, thereby further improving the accuracy of the tritium concentration measurement.

[0054] In one embodiment, diluting the spent fuel solution specifically includes:

[0055] The spent fuel solution was diluted by a preset factor, and the pH of the diluted spent fuel solution was adjusted to neutral to obtain the initial analytical solution.

[0056] The initial analytical solution is diluted to a first preset volume to obtain the first sample solution. Since the spent fuel dissolution solution is acidic, under acidic conditions, hydrogen ions in the solution exchange with tritium ions, causing tritium to exist in the solution in ionic form. Therefore, adjusting the pH of the diluted spent fuel dissolution solution to neutral facilitates tritium extraction, thereby improving the accuracy of the measurement.

[0057] Specifically, there are no restrictions on the method of adjusting the pH of the spent fuel solution.

[0058] For example, an alkaline solution (such as NaOH) is added to the spent fuel solution to neutralize the hydrogen ions in the spent fuel solution, making the spent fuel solution neutral.

[0059] The first preset volume refers to a pre-defined and specific solution volume value. Diluting the initial analytical solution to this volume will bring the solution to a concentration range suitable for subsequent analytical operations (such as distillation in a distillation apparatus).

[0060] For example, the first preset volume is 100 mL.

[0061] The dilution method for the initial analytical solution is not limited.

[0062] For example, deionized water can be used to dilute the initial analytical solution. This reduces the concentration of impurity ions in the initial analytical solution and also avoids introducing other impurity ions during the dilution process, which could affect measurement accuracy.

[0063] In one specific embodiment, please refer to Figure 2 The distillation apparatus includes a round-bottom flask 10, a fractionating head 11, a ground-glass thermometer 12, a condenser 13, a vacuum receiving tube 14, a ground-glass conical flask 15, a heater 16, an iron stand 17, and a four-jaw clamp 18. The round-bottom flask 10 contains spent fuel solution. By gently boiling the diluted spent fuel solution in the round-bottom flask 10, the distillate is collected in the ground-glass conical flask 15 via the condenser 13. The ground-glass thermometer 12 detects the temperature during distillation. The iron stand 17 and the four-jaw clamp 18 are used to secure the round-bottom flask 10. The heater 16 is located at the bottom of the round-bottom flask 10 and is used to heat the spent fuel solution inside. The condenser 13 has a water flow channel from the inlet to the outlet to cool the distillate.

[0064] In one embodiment, obtaining the distillate specifically includes:

[0065] The first sample solution is distilled by micro-boiling to obtain the distillate. Thus, micro-boiling distillation reduces the volatilization of high-boiling-point impurities, allowing more impurities with boiling points higher than tritium and those mainly accompanied by low-boiling-point substances to remain in the distillation flask, reducing the total amount of impurities in the distillate and further improving the accuracy of tritium concentration measurement.

[0066] Specifically, gentle boiling refers to maintaining a solution in a state of slight boiling under relatively mild heating conditions. Fewer bubbles are generated inside the liquid and escape to the surface more slowly. This avoids phenomena such as violent boiling and splashing caused by vigorous boiling, and also reduces the possibility of impurities being introduced due to vigorous agitation or excessive volatilization of certain volatile impurities, which could affect the quality of the distillate.

[0067] In one embodiment, the initial analytical feed solution is the supernatant of a spent fuel dissolution solution whose pH has been adjusted to neutral. This removes insoluble impurities, precipitates, and flocculants that may form under neutral conditions from the spent fuel dissolution solution, thereby further improving measurement accuracy.

[0068] Specifically, the supernatant refers to the relatively clear and uniform liquid at the top of the container when the solution has been treated (such as by adjusting the pH and letting it stand). Solid particles, precipitates, or substances with higher density will settle to the bottom of the container.

[0069] In one embodiment, the process of adding the distillate to a tritium column 20 for filtration specifically includes:

[0070] The distillate is added to the tritium column 20 in multiple batches for filtration. This allows the resin within the column sufficient time for each addition of liquid to undergo adequate ion exchange and adsorption, improving the removal rate of impurities and thus enhancing overall filtration efficiency.

[0071] In one embodiment, adding the distillate to a tritium column 20 for filtration to obtain the target solution specifically includes:

[0072] The tritium column 20 has an inlet at the top and an outlet at the bottom. The distillate enters the tritium column 20 through the inlet and flows out through the outlet after filtration.

[0073] The first portion of the second preset volume of effluent filtered through the tritium column 20 is discarded, and the remaining portion of the effluent filtered through the tritium column 20 is collected as the target solution. This avoids the influence of the low tritium concentration in the first portion of the second preset volume of effluent on the measurement results, thereby improving the accuracy of the measurement.

[0074] Specifically, in the initial stage of filtration, the tritium concentration of the first portion of the effluent filtered through the tritium column 20 is relatively low, while the tritium concentration of the remaining effluent is more accurate and its distribution is more uniform. By discarding the first portion of the second preset volume of effluent and collecting the remaining effluent as the target solution, the influence of the second preset volume of effluent with a lower tritium concentration on the measurement results can be effectively avoided, thereby improving the accuracy of the measurement.

[0075] The second preset volume refers to a predetermined, fixed liquid volume value. After the distillate is filtered through the tritium column 20, the first portion of this volume of liquid in the effluent is discarded.

[0076] The value of the second preset volume is unlimited.

[0077] For example, the second preset volume is 5 mL.

[0078] The inlet refers to the entrance where the distillate enters the tritium column 20.

[0079] The outlet refers to the outlet of the solution after the distillate has been filtered through the tritium column 20.

[0080] The size of the inlet and outlet is not limited.

[0081] For example, the cross-sectional area of ​​the inlet is larger than that of the outlet. Thus, the larger inlet facilitates the entry of the distillate into the tritium column 20, while the smaller outlet allows the tritium column 20 to better filter the distillate, resulting in a purer target solution and more accurate measurement results.

[0082] In one specific embodiment, the distillate enters the tritium column 20 through the inlet, passes through the cation exchange resin 21, the anion exchange resin 22 and the organic impurity adsorption resin 23, and flows out from the outlet.

[0083] Specifically, the distillate first passes through cation exchange resin 21 to remove impurity cations in the solution, which can prevent impurity cations from combining with anions in anion exchange resin 22 to form precipitates that block the pores of anion exchange resin 22, reduce the exchange efficiency of the resin, or even damage the resin structure.

[0084] After the distillate is treated with anion exchange resin 22, the ionic environment of the solution becomes purer, which is beneficial for the organic impurity adsorption resin 23 to function better. If there are a large number of ionic impurities in the solution, it may interfere with the adsorption between the organic impurity adsorption resin 23 and the organic impurities.

[0085] In one embodiment, the process of adding a liquid scintillation solution to the target solution for mixing and obtaining the measurement results using a liquid scintillation counter specifically includes:

[0086] Adjust the volume of the target solution mixed with the liquid scintillation liquid based on the measurement results so that the reading of the liquid scintillation counter is within the preset range.

[0087] Specifically, the accuracy and error range of a liquid scintillation counter vary depending on the count rate range. By adjusting the tritium concentration in the mixture of the target solution and the liquid scintillation liquid, the reading of the liquid scintillation counter can be kept within a preset range, thus reducing the measurement error and enabling a more accurate reflection of the tritium concentration in the target solution.

[0088] The preset range refers to the pre-defined range of liquid scintillation counter readings.

[0089] For example, the reading of the liquid scintillation counter is greater than or equal to 100 and less than or equal to 100,000. For example, the reading of the liquid scintillation counter may be 100, 1000, 10000, or 100000. Maintaining the liquid scintillation counter reading within this range ensures higher accuracy and reliability of the measurement results, makes the data more credible, and reduces errors caused by over- or under-counting.

[0090] In one embodiment, a simulated solution of spent fuel dissolution was prepared, and the simulated solution was pretreated using a distillation apparatus and a tritium column to obtain the purification coefficients of each ion. The results are shown in Table 1.

[0091] Table 1. Purification coefficients of various ions in the simulated solution of spent fuel dissolution.

[0092] Element types Purification coefficients of various ions by distillation Purification coefficients of various ions in tritium column method Sr <![CDATA[1.79×10 4 ]]> <![CDATA[6.91×10 3 ]]> Zr <![CDATA[2.28×10 4 ]]> <![CDATA[8.50×10 2 ]]> Cs <![CDATA[3.61×10 4 ]]> <![CDATA[3.97×10 2 ]]> Sm <![CDATA[4.20×10 3 ]]> <![CDATA[2.40×10 4 ]]> Eu <![CDATA[2.39×10 3 ]]> <![CDATA[2.39×10 4 ]]>

[0093] The data in the table above shows that the method of distillation followed by tritium column percolation can meet the requirement of a high purification coefficient for the pretreatment of spent fuel dissolved liquid.

[0094] In one embodiment, the recovery rate of this method was tested using the standard tritium-water addition method in spent fuel reprocessing 1AF (spent fuel dissolution) solution, and the results are shown in Table 2:

[0095] Table 2. Experimental Results of Standard Tritium Water Recovery Rate

[0096] Distillation Tritium column method Average recovery rate 103.2％(n＝3) 105.1％(n＝2)

[0097] As can be seen from the experimental data of standard tritium water recovery rate in the table above, the recovery rate of this method is good. Therefore, it can be inferred that this method is more accurate in measuring tritium in 1AF solution, and solves the problem that tritium in spent fuel solution is not easy to measure accurately.

[0098] In one embodiment, the tritium content in the 1AF solution was analyzed by distillation.

[0099] Specifically, 100 μL of 1AF solution diluted 1000 times was added to 50 mL of distilled water and placed in a 100 mL flask. Distillation was performed using the prepared distillation apparatus, with the temperature slowly increased to approximately 140 °C until the solution reached a gentle boil. A sample was taken when distillation was complete. 500 μL of the sample was added to 10 mL of liquid scintillation solution and measured using liquid scintillation. The results are shown in Table 3.

[0100] Table 3. Measurement results of tritium content in AF solution by distillation method

[0101] Measurement items Measured value / Bq Measurement items Measured value / Bq Distillate 1 1.807 Distillation residue 1 8537.165 Distillate 2 1.466 Distillation residue 2 8502.709 Distillate 3 1.258 Distillation residue 3 8341.207

[0102] The concentration of tritium in the 1AF solution was calculated to be 1.51 × 10⁻⁶. 9 Bq / L. The table above shows that the measured values ​​of the distillation residue are relatively high, indicating that the interfering nuclides remained in the mother liquor and were not distilled out with the tritium water.

[0103] In one embodiment, a standard tritium water addition recovery rate test was performed using a distillation method.

[0104] Specifically, 1 mL of 1AF solution diluted 1000 times and 50 μL of standard tritium water were added to 50 mL of distilled water and placed in a 100 mL flask. Distillation was performed using the prepared distillation apparatus at a temperature of 140 °C. Samples were taken when distillation was complete. 1 mL of the distillate and 50 μL of the remaining distillate were then added to 10 mL of liquid scintillation solution and measured using liquid scintillation. The results are shown in Table 4.

[0105] Table 4. Results of the recovery rate test for standard tritium water added by distillation method.

[0106] Measurement items Measured value / Bq Measurement items Measured value / Bq Distillate 1 53.267 Distillation residue 1 7506.174 Distillate 2 52.160 Distillation residue 2 7435.007 Distillate 3 58.119 Distillation residue 3 7761.406

[0107] Calculations showed that the recovery rates for the three trials were 100.8%, 98.8%, and 110.1%, with an average recovery rate of 103.2%, indicating that the tritium recovery rate was quite good.

[0108] In one embodiment, the tritium content in the 1AF solution was analyzed by tritium column chromatography, and the recovery rate of the added standard tritium water was tested.

[0109] Specifically, the steps include the following:

[0110] S1: Dilute the 1AF solution 1000 times and store it for later use;

[0111] S2: Take 10 μL of standard tritium water, dilute it with deionized water to 10 mL, and store it for later use;

[0112] S3: Take 0.25 mL of diluted standard tritium water and 0.25 mL of diluted 1AF solution into a 50 mL centrifuge tube, dilute with deionized water to 25 mL, and shake well;

[0113] S4: Take 20 mL of the solution obtained in step 3 and add it to the top of the tritium column 20. Let it pass through the tritium column 20 under the action of gravity. Discard the first 5 mL of effluent and collect the remaining 15 mL of effluent.

[0114] S5: Repeat steps S3 and S4, but do not add diluted standard tritium water in step S3. Keep other operating steps unchanged and repeat the experiment.

[0115] S6: Take 1.5 mL of each sample of the effluent collected in steps S4 and S5, add 15 mL of liquid scintillation solution, and perform measurement using liquid scintillation. The measurement results are shown in Table 5.

[0116] Table 5. Tritium content in AF solution and recovery results of standard tritium water addition test by tritium column method.

[0117]

[0118]

[0119] The concentration of tritium water in the 1AF solution was calculated to be 1.63 × 10⁻⁶. 9 Bq / L, with an average recovery rate of 105.1% when standard tritium water was added.

[0120] In the description of this application, the references to terms such as "in one embodiment," "in some embodiments," "in a specific embodiment," or "exemplary," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the embodiments of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine the different embodiments or examples described in this application, as well as the features of the different embodiments or examples.

[0121] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. An analytical measurement method for measuring the tritium concentration in spent fuel dissolved liquid, characterized in that, The analytical measurement method includes the following steps: The spent fuel solution is diluted and distilled to obtain a distillate. The dilution of the spent fuel solution includes: diluting the spent fuel solution by a preset factor and adjusting the pH of the diluted spent fuel solution to neutral to obtain an initial analytical solution; and diluting the initial analytical solution to a first preset volume to obtain a first sample solution. The process of obtaining the distillate includes: distilling the first sample solution by micro-boiling to obtain the distillate; The distillate was added to a tritium column and filtered to obtain the target solution; The target solution is mixed with a liquid scintillation solution, and the measurement results are obtained using a liquid scintillation counter. The tritium concentration is obtained based on the measurement results.

2. The analytical measurement method according to claim 1, characterized in that, The step of diluting the initial analytical solution to a first preset volume to obtain the first sample solution specifically includes: The initial analytical solution was diluted with deionized water.

3. The analytical measurement method according to claim 1, characterized in that, The initial analytical feed solution is the supernatant of the solution after the pH of the spent fuel dissolution solution has been adjusted to neutral.

4. The analytical measurement method according to any one of claims 1-3, characterized in that, The tritium column comprises at least one of a cation exchange resin, an anion exchange resin, and an organic impurity adsorption resin.

5. The analytical measurement method according to any one of claims 1-3, characterized in that, The step of adding the distillate to a tritium column for filtration specifically includes: The distillate was added to the tritium column in multiple portions for filtration.

6. The analytical measurement method according to any one of claims 1-3, characterized in that, The step of adding the distillate to a tritium column for filtration to obtain the target solution specifically includes: The tritium column has an inlet at the top and an outlet at the bottom. The distillate enters the tritium column through the inlet, is filtered, and then flows out through the outlet. Discard the first portion of the second preset volume of effluent filtered through the tritium column, and collect the remaining portion of the effluent filtered through the tritium column as the target solution.

7. The analytical measurement method according to any one of claims 1-3, characterized in that, The step of adding liquid scintillation liquid to the target solution for mixing and obtaining measurement results using a liquid scintillation counter specifically includes: The volume of the target solution mixed with the liquid scintillation liquid is adjusted according to the measurement results so that the reading of the liquid scintillation counter is within a preset range.

8. The analytical measurement method according to claim 7, characterized in that, The reading of the liquid scintillation counter is greater than or equal to 100 and less than or equal to 100,000.

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