Analysis and measurement method

Abstract

The embodiment of the invention provides an analysis and measurement method, which is used for measuring the concentration of tritium in a spent fuel dissolving solution, and 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, and filtering to obtain a target solution; adding liquid flashing liquid into the target solution for mixing, and obtaining a measurement result through a liquid flashing counter; and obtaining the tritium concentration according to the measurement result. The analysis method provided by the embodiment of the invention is high in accuracy of measuring the tritium concentration in the spent fuel dissolving solution.

Description

Technical Field

[0001] The present application relates to the technical field of spent fuel post-processing analysis, and in particular to an analysis and measurement method. Background Art

[0002] In the traditional spent fuel reprocessing process, the spent fuel components are directly dissolved after shearing. During the shearing and dissolving process of spent fuel, most of the tritium will be transferred into the dissolving liquid. Tritium cannot be treated by conventional three-waste systems, so it is the main radioactive nuclide discharged into the environment during nuclear power plants and nuclear fuel reprocessing. Since the maximum energy of tritium's β-ray is 18keV and the average energy is 5.7keV, while other nuclides (such as 41 Ar and 90 The high-energy radiation generated by Sr) will be greater than the decay energy of tritium, so the detection or monitoring of tritium is very difficult. In addition, the analytical measurement method for measuring the tritium concentration in the spent fuel solution in the related art has a low measurement accuracy. Summary of the invention

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

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

[0005] The embodiment of the present application provides a method for analyzing and measuring a tritium concentration in a spent fuel solution, and the method for analyzing and measuring comprises the following steps:

[0006] diluting and distilling the spent fuel solution to obtain a distillate;

[0007] adding the distillation distillate into a tritium column for filtration to obtain a target solution;

[0008] adding liquid scintillation liquid to the target solution for mixing, and obtaining a measurement result by a liquid scintillation counter;

[0009] The tritium concentration is obtained according to the measurement result.

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

[0011] Diluting the spent fuel solution by a preset multiple, and adjusting the pH of the diluted spent fuel solution to neutral, so as to obtain an initial analysis solution;

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

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

[0014] Deionized water was used to dilute the initial analysis solution.

[0015] In one embodiment, the step of obtaining the distillation distillate specifically comprises:

[0016] The first sample liquid is slightly boiled and distilled to obtain the distillation distillate.

[0017] In one embodiment, the initial analysis solution is the supernatant of the solution after the pH of the spent fuel solution is adjusted to neutral.

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

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

[0020] The distillate is added to the tritium column for filtration in multiple portions.

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

[0022] The tritium column has a liquid inlet at the top and a liquid outlet at the bottom. The distillate enters the tritium column from the liquid inlet and flows out from the liquid outlet after being filtered.

[0023] The first part of the second preset volume of the effluent filtered through the tritium column is discarded, and the remaining part of the effluent filtered through the tritium column is collected as the target solution.

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

[0025] The volume of the target solution mixed with the liquid scintillator is adjusted according to the measurement result 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] The embodiment of the present application provides an analytical measurement method for measuring the tritium concentration in a spent fuel solution, and the analytical measurement method includes the following steps: diluting and distilling the spent fuel solution to obtain a distillate; adding the distillate to a tritium column for filtration to obtain a target solution; adding liquid scintillator to the target solution for mixing, and obtaining a measurement result through a liquid scintillation counter; and obtaining the tritium concentration based on the measurement result. Thus, on the one hand, through the dilution and distillation steps, most of the interfering ions and impurities can be preliminarily removed without adding a variety of chemical reagents, and the equipment and operation process are simple. On the other hand, through the further filtering effect of the tritium column, the residual ionic impurities and organic impurities in the distillate can be effectively removed, reducing the interference of these impurities on the measurement of tritium concentration, thereby further improving the accuracy of measuring tritium concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of an analysis and measurement method according to an embodiment of the present application;

[0029] Figure 2 This is a schematic structural diagram of a distillation device according to another embodiment of the present application;

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

[0031] Description of Reference Numerals

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

[0033] The main instruments currently 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 facility buildings, chimneys and process monitoring processes.

[0034] In the related art, the analysis of tritium in reactor decommissioning waste uses tritium humidification and high-temperature analysis to collect tritiated water, and then uses a liquid scintillation counter to measure it.

[0035] In the related art, a freeze-drying vacuum system equipped with a trap is used to extract HTO from tritium in the soil and plants around decommissioned facilities, and then a liquid scintillation counter is used to measure it.

[0036] In the related art, for tissue free water tritium (TFWT) in plant samples around nuclear facilities, a low-temperature analysis method is used to process the samples, and then a liquid scintillation counter is used to detect the tritium content in the plant samples around nuclear facilities.

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

[0038] In the related art, for the determination of tritium in spent fuel reprocessing solution, the sample is treated by distillation, and then tritium is measured using a liquid scintillation counter. However, this distillation method has complex equipment and requires the use of multiple chemical reagents such as AgNO3, HNO3, NaOH, etc., and the operation is complicated.

[0039] Since there are many interfering ions (such as U, Sr, Cs, Zr, etc.) in the spent fuel reprocessing solution, and the content of these elements is very high and the radioactivity is very high, the degree of purification required is very high. However, methods such as humidified high-temperature analysis, freeze drying, low-temperature analysis, and electrolytic concentration are not suitable for processing such samples and cannot eliminate the influence of interfering ions.

[0040] An embodiment of the present application provides an analytical measurement method for measuring the tritium concentration in spent fuel solution. 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 distillation distillate into the tritium column 20 for filtration to obtain the target solution.

[0043] S3: Add liquid scintillation fluid to the target solution to mix, and obtain the measurement result by liquid scintillation counter.

[0044] S4: Obtain tritium concentration according to the measurement result.

[0045] Specifically, spent fuel solution refers to the solution obtained after dissolving spent fuel, which contains a variety of elements and radioactive substances.

[0046] Distillation distillate refers to a solution obtained by utilizing the different boiling points of the components in the spent fuel solution to evaporate the low-boiling-point components and then condensing the evaporated components.

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

[0048] The structure of the tritium column 20 is not limited as long as it can filter the impurities in the distillation 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 can effectively filter impurities in the distillate, thereby improving the accuracy of measuring the tritium concentration.

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

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

[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 liquid scintillator and converts them into electrical signals for analysis and processing, thereby determining the content of radioactive nuclides in the sample.

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

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

[0055] The spent fuel solution is diluted by a preset multiple, and the pH of the diluted spent fuel solution is adjusted to neutral to obtain an initial analysis solution.

[0056] The initial analysis solution is diluted to a first preset volume to obtain a first sample solution. Since the spent fuel solution is acidic, under acidic conditions, hydrogen ions in the solution will exchange with tritium ions, so that tritium exists in the solution in the form of ions. Therefore, by adjusting the pH of the diluted spent fuel solution to neutral, it is easy to extract tritium, thereby improving the accuracy of the measurement.

[0057] Specifically, the method of adjusting the pH of the spent fuel solution is not limited.

[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-set and clear solution volume value. When the initial analysis solution is diluted to this volume, the solution can reach a concentration range suitable for subsequent analysis operations (such as entering a distillation device for distillation, etc.).

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

[0061] The initial analysis solution can be diluted in any manner.

[0062] For example, deionized water is used to dilute the initial analysis solution, thereby reducing the concentration of impurity ions in the initial analysis solution and preventing other impurity ions from being introduced during the dilution process, thereby affecting the measurement accuracy.

[0063] In a specific embodiment, please refer to Figure 2 The distillation device includes a round bottom flask 10, a fractionating head 11, a ground-mouth thermometer 12, a condenser 13, a vacuum receiving tube 14, a ground-mouth conical flask 15, a heater 16, an iron stand 17 and a four-claw clamp 18. The round bottom flask 10 contains spent fuel solution. The diluted spent fuel solution in the round bottom flask 10 is slightly boiled, and the distillate is collected by the ground-mouth conical flask 15 through the condenser 13. The ground-mouth thermometer 12 detects the temperature during distillation. The iron stand 17 and the four-claw clamp 18 are used to fix the round bottom flask 10. The heater 16 is set at the bottom of the round bottom flask 10 to heat the spent fuel solution in the round bottom flask 10. The condenser 13 has a water flow channel from the water inlet to the water outlet to cool the distillate.

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

[0065] The first sample liquid is subjected to micro-boiling distillation to obtain a distillate. Thus, through micro-boiling distillation, the volatilization of high-boiling impurities can be reduced, so that more impurities with a boiling point higher than tritium and mainly accompanying low-boiling substances remain in the distillation flask, reducing the total amount of impurities in the distillate, thereby further improving the accuracy of tritium concentration measurement.

[0066] Specifically, micro-boiling refers to keeping the solution in a slightly boiling state under relatively mild heating conditions. The bubbles generated inside the liquid are fewer and escape from the liquid surface more slowly, which on the one hand avoids the phenomena of violent boiling and splashing caused by the solution, and on the other hand reduces the impurities that may be brought in by violent stirring or the excessive volatilization of certain volatile impurities, which may affect the quality of the distillate.

[0067] In one embodiment, the initial analysis liquid is the supernatant of the spent fuel solution after the pH of the spent fuel solution is adjusted to neutral, thereby removing insoluble impurities, precipitation, and flocculants that may be formed under neutral conditions in the spent fuel solution, thereby further improving the measurement accuracy.

[0068] Specifically, the supernatant refers to the relatively clear and uniform liquid on the top of the solution after solid particles, precipitation or denser substances therein settle to the bottom of the container when the solution is treated (such as pH adjustment and then standing).

[0069] In one embodiment, the distillate is added to the tritium column 20 for filtering, which specifically includes:

[0070] The distillate is added to the tritium column 20 for filtration in multiple times. Thus, by adding the distillate to the tritium column 20 for filtration in multiple times, the resin in the tritium column 20 has enough time to fully perform ion exchange and adsorption treatment on the liquid added each time, thereby improving the removal rate of impurities and thus improving the overall filtration efficiency.

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

[0072] The tritium column 20 has a liquid inlet at the top and a liquid outlet at the bottom. The distillate enters the tritium column 20 from the liquid inlet and flows out from the liquid outlet after being filtered.

[0073] The first part of the second preset volume of effluent filtered by the tritium column 20 is discarded, and the remaining part of the effluent filtered by the tritium column 20 is collected as the target solution. In this way, the influence of the lower tritium concentration in the first part of the second preset volume of effluent on the measurement result can be avoided, thereby improving the accuracy of the measurement.

[0074] Specifically, at the beginning of filtration, the tritium concentration of the front part of the effluent filtered through the tritium column 20 is relatively low, and the tritium concentration of the remaining part of the effluent is more accurate and its distribution is more uniform. By discarding the front part of the second preset volume of the effluent and collecting the remaining part of the effluent as the target solution, the influence of the front part of the second preset volume of the effluent with a lower tritium concentration on the measurement result 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 front part of the effluent, that volume of liquid, is discarded.

[0076] The value of the second preset volume is not limited.

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

[0078] The liquid inlet refers to the inlet through which the distillate enters the tritium column 20 .

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

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

[0081] For example, the cross-sectional area of ​​the liquid inlet is larger than the cross-sectional area of ​​the liquid outlet. Thus, the larger liquid inlet facilitates the distillate to enter the tritium column 20, and the smaller liquid outlet facilitates the tritium column 20 to better filter the distillate, making the target solution purer, thereby making the measurement result more accurate.

[0082] In a specific embodiment, the distillate enters the tritium column 20 from the liquid 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 liquid outlet.

[0083] Specifically, the distillate is first passed through the cation exchange resin 21 to remove impure cations in the solution, which can prevent the impurity cations from combining with the anions in the anion exchange resin 22 to form precipitation that blocks the pores of the anion exchange resin 22, reduces the exchange efficiency of the resin, and even damages the resin structure.

[0084] After the distillate is treated with the anion exchange resin 22, the ion environment of the solution can be made simpler, which is conducive to the better function of the organic impurity adsorption resin 23. 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, adding liquid scintillator to the target solution for mixing, and obtaining the measurement result by a liquid scintillation counter specifically includes:

[0086] The volume of the target solution mixed with the liquid scintillator was adjusted according to the measurement results so that the reading of the liquid scintillation counter was within the preset range.

[0087] Specifically, the measurement accuracy and error range of the liquid scintillation counter are different in different counting rate ranges. By adjusting the tritium concentration in the mixed solution of the target solution and the liquid scintillator, the reading of the liquid scintillation counter is within a preset range, so that the measurement error of the liquid scintillation counter can be relatively small, thereby being able to more accurately reflect the concentration of tritium in the target solution.

[0088] The preset range refers to the pre-set interval 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 100000. For example, the reading of the liquid scintillation counter is 100, 1000, 10000 or 100000. Keeping the reading of the liquid scintillation counter in the above range can make the accuracy and reliability of the measurement results higher, the data more credible, and can reduce the errors caused by over- or under-counting.

[0090] In one embodiment, a simulated liquid of spent fuel solution was prepared, and the simulated liquid was pretreated using a distillation device and a tritium column method to obtain the purification coefficient 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 solution

[0092] Element Type Purification coefficient of each ion by distillation method Purification coefficients of various ions by 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] It can be seen from the data in the above table that the method of using distillation + tritium column can meet the requirements of high purification coefficient of spent fuel solution pretreatment.

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

[0095] Table 2 Standard tritium water recovery experimental results

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

[0097] It can be seen from the experimental data of standard tritium water recovery rate in the above table that the recovery rate of this method is good. It can be inferred that this method is more accurate in measuring tritium in 1AF solution, which solves the problem of accurate measurement of tritium in spent fuel solution.

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

[0099] Specifically, take 100 μL of 1AF solution diluted 1000 times, add it to 50 mL of distilled water, place it in a 100 mL flask, and use the above-built distillation device to distill. Slowly increase the heating temperature to about 140°C to make the solution slightly boil. Take a sample when the distillation is complete. Take 500 μL in 10 mL of liquid scintillator and measure it with liquid scintillator. The measurement results are shown in Table 3:

[0100] Table 3 The results of tritium content measurement in 1AF solution by distillation analysis

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

[0102] By calculation, the concentration of tritium in 1AF solution is: 1.51×10 9 Bq / L. From the table above, it can be seen that the measured value of the distillation residue is relatively high, indicating that the interfering nuclides are all left in the distillation mother liquor and are not distilled out with the tritium water.

[0103] In one embodiment, a recovery rate test of adding standard tritium water by distillation was performed.

[0104] Specifically, take 1mL of 1AF solution diluted 1000 times and 50μL of standard tritium water, add them to 50mL of distilled water, place them in a 100mL flask, and use the built distillation device for distillation, and set the heating temperature to 140℃. Take samples when the distillation is complete. Take 1mL of distillate and 50μL of distillation residue in 10mL of liquid scintillator, respectively, and measure them with liquid scintillator. The measurement results are shown in Table 4:

[0105] Table 4 Recovery test results of standard tritium water added by distillation method

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

[0107] Through calculation, the recovery rates of the three times were 100.8%, 98.8%, and 110.1% respectively, and the average recovery rate was 103.2%, which shows that the recovery rate of tritium is good.

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

[0109] The specific steps include:

[0110] S1: dilute 1AF solution 1000 times and keep for later use;

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

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

[0113] S4: quantitatively take 20 mL of the solution obtained in step 3, add it to the top of the tritium column 20, allow it to 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 step S4 and step S5, add 15 mL of liquid scintillator, and measure with liquid scintillator. The measurement results are shown in Table 5:

[0116] Table 5 Analysis of tritium content in 1AF solution by tritium column method and test results of recovery rate of standard tritium water addition

[0117]

[0118]

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

[0120] In the description of the present application, the description with reference to the terms "in one embodiment", "in some embodiments", "in a specific embodiment", or "exemplary" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0121] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. An analytical measurement method for measuring the tritium concentration in spent fuel solution, characterized in that: The analytical measurement method comprises the following steps: diluting and distilling the spent fuel solution to obtain a distillate; adding the distillation distillate into a tritium column for filtration to obtain a target solution; adding liquid scintillation liquid to the target solution for mixing, and obtaining a measurement result by a liquid scintillation counter; The tritium concentration is obtained according to the measurement result.

2. The analytical measurement method according to claim 1, characterized in that: The diluting the spent fuel solution specifically includes: Diluting the spent fuel solution by a preset multiple, and adjusting the pH of the diluted spent fuel solution to neutral, so as to obtain an initial analysis solution; The initial analysis solution is diluted to a first preset volume to obtain a first sample solution.

3. The analytical measurement method according to claim 2, characterized in that: The step of diluting the initial analysis solution to a first preset volume to obtain a first sample solution specifically includes: Deionized water was used to dilute the initial analysis solution.

4. The analytical measurement method according to claim 2, characterized in that: The obtaining of distillation distillate specifically comprises: The first sample liquid is slightly boiled and distilled to obtain the distillation distillate.

5. The analytical measurement method according to claim 2, characterized in that: The initial analysis liquid is the supernatant of the solution after the pH of the spent fuel solution is adjusted to neutral.

6. The analytical measurement method according to any one of claims 1 to 5, characterized in that: The tritium column includes at least one of a cation exchange resin, an anion exchange resin and an organic impurity adsorption resin.

7. The analytical measurement method according to any one of claims 1 to 5, characterized in that: The step of adding the distillation distillate into a tritium column for filtering specifically comprises: The distillate is added to the tritium column for filtering in multiple times.

8. The analytical measurement method according to any one of claims 1 to 5, characterized in that: The step of adding the distillation distillate into a tritium column for filtration to obtain the target solution specifically comprises: The tritium column has a liquid inlet at the top and a liquid outlet at the bottom. The distillate enters the tritium column from the liquid inlet and flows out from the liquid outlet after being filtered. The first part of the second preset volume of the effluent filtered through the tritium column is discarded, and the remaining part of the effluent filtered through the tritium column is collected as the target solution.

9. The analytical measurement method according to any one of claims 1 to 5, characterized in that: The step of adding liquid scintillator to the target solution for mixing and obtaining the measurement result by a liquid scintillation counter specifically includes: The volume of the target solution mixed with the liquid scintillator is adjusted according to the measurement result so that the reading of the liquid scintillation counter is within a preset range.

10. The analytical measurement method according to claim 9, 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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