Method for measuring sampling efficiency of a bubble method tritium sampler

Abstract

The present application relates to a kind of bubble method tritium sampler sampling efficiency determination method, gas generated by water vapor generator is passed into tritium sampler, sampling flow in gas path is controlled by flowmeter, after sampling, sampling efficiency is the ratio of the mass of tritium sampler and the mass of water vapor generator.The present application realizes using water vapor generator to generate water vapor as sampling gas source to replace non-radioactive method of tritium water vapor gas source, while using weighing method to measure and calculate bubble method tritium sampler, sampler sampling efficiency, effectively avoids the problem of tritium water vapor activity concentration traceability, avoids the risk of contamination of tritium sampler, sampler and tritiated water vapor leakage in the process of efficiency determination using tritiated water vapor gas source.The present application provides a convenient, fast, non-polluting, no need to operate radioactive source and safe determination method for bubble method tritium sampler, sampler sampling efficiency determination.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sample sampling efficiency measurement, and particularly relates to a method for determining sampling efficiency of a bubble method tritium sampler. BACKGROUND

[0002] In the process of gas monitoring in environmental monitoring and industrial sites, chimney exhaust streams, process pipelines, glove box atmospheres, etc., the use of tritium samplers and samplers is a key tool to ensure the safety and compliance of gas emissions. These devices are mainly used to detect and quantify the concentration of tritium (a radioactive isotope) in the air or exhaust gas to assess the potential risk of radiation exposure. Bubble method is a commonly used sampling technology, which is widely used due to its simplicity and effectiveness.

[0003] Bubble method is a physical and chemical process that separates and captures target substances (such as tritiated water vapor HTO) in gas by introducing air or other gases into a container containing absorbing liquid. Specifically, when the gas passes through a bubble bottle containing a specific solvent (usually water or aqueous solution), the solvent in the bubble bottle can effectively absorb the tritiated water vapor in the gas. Although the device used in the bubble method has a simple structure and low cost, it is very important to maximize the capture of target gas. If the sampling efficiency is low, part of the target gas may not be captured, resulting in a lower measurement result that cannot truly reflect the actual concentration. How to ensure the high sampling efficiency of the bubble method is the key to ensuring the reliability and repeatability of measurement data.

[0004] In the determination of sampling efficiency of tritium samplers and samplers, there are usually two main methods: theoretical calculation method and experimental measurement method. The theoretical calculation method is based on the basic principles of the bubble method, which uses mathematical models to predict and calculate the sampling efficiency. This method relies on a series of assumptions and physical and chemical laws, such as gas solubility, diffusion coefficient, flow rate, temperature and pressure parameters, and specific formulas such as Henry's law, Fick's first law, and mass transfer coefficient. In theory, these formulas can be used in combination with specific device geometry and operating conditions to calculate the expected sampling efficiency. However, due to the complexity and variability of actual operating conditions, theoretical calculations often fail to accurately reflect the actual situation, so they are often used as preliminary estimates or auxiliary means. Experimental measurement method is more direct, which involves using standard tritiated water (HTO) with known activity concentration, generating tritiated water vapor through the bubble method, and then allowing the vapor to pass through the bubble device (absorption bottle) of the sampler or sampler for capture. After that, the amount of tritium captured in the absorption bottle is measured by a liquid scintillation counter (LSC) to determine the sampling efficiency. Although the experimental measurement method can provide more accurate sampling efficiency data, it also has some problems:

[0005] (1) Traceability problem: The activity of the standard tritiated water with known activity concentration cannot be completely traced to the international standard, which will affect the accuracy of the measurement results.

[0006] (2) Pollution risk: Any leakage during the handling of radioactive substances can cause environmental and personnel contamination.

[0007] (3) Safety risk: If tritiated water vapor leaks occur during operation, not only will it cause environmental pollution, but it may also pose a threat to the health of the operator.

[0008] Therefore, there is an urgent need for a convenient, fast, non-polluting, non-radioactive source operation and safe method for measuring the sampling efficiency of a bubble method tritium sampler. SUMMARY

[0009] The present application discloses a method for measuring the sampling efficiency of a bubble method tritium sampler, to solve the problems of low accuracy, pollution and safety risk in the above-mentioned sampling efficiency measurement methods of tritium samplers and samplers.

[0010] The present application adopts the following technical solutions:

[0011] The present application provides a method for measuring the sampling efficiency of a bubble method tritium sampler, comprising the following steps: passing the gas generated by a water vapor generator into a tritium sampler, the tritium sampler comprising a plurality of absorption bottles containing an absorbent, the plurality of absorption bottles being connected in series, the first absorption bottle being connected to the water vapor generator through a gas pipeline, the gas pipeline being provided with a gas pump and a flow regulating valve, the sampling flow in the gas circuit being controlled by a flow meter, and the sampling efficiency being the ratio of the mass added to the tritium sampler to the mass reduced by the water vapor generator after sampling.

[0012] Preferably, the tritium sampler comprises a first-stage absorption bottle and a second-stage absorption bottle connected in series, one end of the first-stage absorption bottle being connected to the water vapor generator through a gas pipeline, the other end of the first-stage absorption bottle being connected to one end of the second-stage absorption bottle, and the other end of the second-stage absorption bottle being connected to an exhaust pipeline, the exhaust pipeline being provided with a flow meter.

[0013] Preferably, the absorbent is ethanol.

[0014] Preferably, the sampling flow includes the instantaneous flow displayed by the flow meter and the cumulative sampling flow, wherein the instantaneous flow is 55-65 L / h, and the cumulative sampling flow is 0.5-2 m 3 .

[0015] Preferably, the instantaneous flow is 60 L / h, and the cumulative sampling flow is 1.5 m 3 .

[0016] Preferably, the sampling efficiency = (the increased mass of the first-stage absorption bottle + the increased mass of the second-stage absorption bottle) / the decreased mass of the water vapor generator x 100%.

[0017] Preferably, the sampling efficiency is measured to be more than 99% by the measurement method.

[0018] The second aspect of the present application provides a sampling device of a bubble method tritium sampler, comprising a water vapor generator and a tritium sampler, the tritium sampler comprising a plurality of absorption bottles, the plurality of absorption bottles being sequentially connected in series, the first absorption bottle being connected in communication with the water vapor generator through a gas pipeline, and the last absorption bottle being connected in communication with an exhaust pipeline.

[0019] Preferably, a gas suction pump and a flow regulating valve are sequentially arranged on the gas pipeline in the direction of gas flow, and a flow meter is arranged on the exhaust pipeline.

[0020] Preferably, the gas pipeline, through which the gas is introduced into the absorption bottle, extends below the liquid surface of the ethylene glycol, and the gas pipeline, through which the gas is discharged, is located above the liquid surface of the ethylene glycol.

[0021] The technical solution adopted by the present application can achieve the following beneficial effects:

[0022] (1) The conventional bubble method sampling efficiency determination usually relies on standard tritiated water (HTO) with a known activity concentration, which is tested by generating tritiated water vapor through the bubble method. However, this method has obvious safety hazards, including the risk of tritiated water vapor leakage and potential contamination of the environment and personnel. The present application completely avoids the use of radioactive substances by using a water vapor generator to generate water vapor as a sampling gas source, which not only eliminates the safety risks of handling radioactive substances, but also simplifies the experimental operation process and reduces the need for special protective equipment.

[0023] (2) The tritiated water vapor generated by the conventional method using standard tritiated water with a known activity concentration cannot be traced back to the international standard, which affects the accuracy of the measurement results. The present application directly measures the decreased mass of the water vapor generator and the increased mass of the tritium sampler by weighing method, thereby calculating the sampling efficiency. This measurement method based on the law of conservation of mass is more intuitive and reliable, and can provide more accurate sampling efficiency data.

[0024] (3) The present application simplifies the entire sampling efficiency determination operation process, uses a water vapor generator and a flow meter to control the sampling flow in the gas circuit, making the experimental device simpler and easier to use. At the same time, the design of sequentially connecting a plurality of absorption bottles can effectively improve the trapping efficiency and reduce sample loss. In addition, the arrangement of the gas suction pump and the flow regulating valve makes the flow control more accurate and the operation more convenient.

[0025] (4) Traditional methods pose a significant risk of environmental pollution when using tritized water vapor for sampling efficiency determination. Even with strict safety measures, the possibility of leakage cannot be completely eliminated. This invention completely eliminates this risk by using water vapor as the sampling gas source. Water vapor itself is non-toxic and harmless, and even if leakage occurs, it will not cause any pollution to the environment.

[0026] (5) The present invention uses a steam generator and a weighing method to determine the sampling efficiency of a bubbling method tritium sampler and a sampler, which has the advantages of avoiding the use of radioactive materials, improving the accuracy of measurement results, simplifying the operation process, and reducing the risk of environmental pollution. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 This is a flowchart of the sampling efficiency determination process in Example 1.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Steam generator; 2. Vacuum pump; 3. Flow regulating valve; 4. First-stage absorption bottle; 5. Second-stage absorption bottle; 6. Ethylene glycol; 7. Flow meter. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly indicated.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a magnetic connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0033] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] This embodiment provides a method for determining the sampling efficiency of a bubbling tritium sampler, including the following steps: introducing gas generated by a steam generator into the tritium sampler, controlling the sampling flow rate in the gas path by a flow meter, and after sampling, the sampling efficiency is the ratio of the mass increase of the tritium sampler to the mass decrease of the steam generator.

[0035] Currently, the most accurate method for determining the sampling efficiency of a bubble-type tritium sampler is experimental measurement. However, this method requires using standard tritium water with a known activity concentration as raw material. Tritized water vapor is generated through bubbling, then captured by a sampler or sampler. Finally, a liquid scintillation counter is used to measure the amount of tritium captured in the sampler or sampler. The sampling efficiency is calculated based on the captured amount of tritium and the initial input amount. The experimental measurement may introduce errors in several steps: the method used to measure the standard tritium water with a known activity concentration, and whether the given activity concentration accurately reflects the tritium concentration, are uncertain; whether the sampler or sampler can capture all the generated tritized water vapor is also uncertain; and the final measurement of the tritium amount using a liquid scintillation counter itself contains errors. Therefore, the experimental measurement in the existing technology contains errors in multiple steps, leading to a larger error and lower accuracy in the final sampling efficiency measurement result. To address this problem, this invention proposes a novel method for determining sampling efficiency. It replaces the traditional method of generating tritized water vapor using a steam generator instead of standard tritium water with known activity concentration through a bubbling method. This effectively avoids the difficulty in tracing the activity concentration of standard tritium water and reduces the risk of contamination of the tritium sampler and sampler, as well as leakage of tritized water vapor (HTO), that may occur during efficiency determination using a tritized water vapor HTO gas source. In this invention, the sampling efficiency is the ratio of the mass gained by the tritium sampler to the mass lost by the steam generator. This invention does not perform LSC measurement on the amount of tritium captured in the tritium sampler, simplifying the operation and avoiding unavoidable errors in LSC measurement. Furthermore, this invention directly uses a calibrated analytical balance for mass measurement, further improving the accuracy of sampling efficiency measurement.

[0036] In a further embodiment, the tritium sampler includes multiple absorption bottles connected in series, with the first absorption bottle connected to a water vapor generator via a gas pipe.

[0037] This invention employs multiple absorption bottles connected in series to form a multi-stage collection system. Each stage of the absorption bottle captures a portion of the target gas (such as water vapor), significantly improving overall collection efficiency. Even if the first-stage absorption bottle fails to completely capture all the gas, subsequent absorption bottles can continue to capture the remaining portion, ensuring minimal sample loss. Multiple absorption bottles allow for better gas distribution, preventing overload caused by excessive flow in a single bottle. By rationally designing the volume and structure of each absorption bottle, the gas flow can be evenly distributed across them, improving collection effectiveness. The multi-stage absorption system effectively reduces gas flow pulsations and fluctuations, providing more stable sampling conditions and ensuring accurate measurement results. The use of multiple absorption bottles also facilitates maintenance and reduces errors throughout the sampling and measurement process. When one absorption bottle requires maintenance or replacement, others can continue operating, ensuring continuous system operation. This modular design makes maintenance and repair more convenient and efficient; the collection results from multiple absorption bottles allow for more data points and cross-validation. This helps identify potential problems, such as a decrease in the collection efficiency of a particular absorption bottle, allowing for timely adjustments. Multi-stage absorption systems can reduce random errors caused by individual absorption bottles through multiple collections and measurements, thus improving the reliability and accuracy of measurement results.

[0038] In a further embodiment, the tritium sampler includes a first-stage absorption bottle and a second-stage absorption bottle connected in series. One end of the first-stage absorption bottle is connected to a water vapor generator through a gas pipe, and the other end of the first-stage absorption bottle is connected to one end of the second-stage absorption bottle. The other end of the second-stage absorption bottle is connected to an exhaust pipe, and a flow meter is installed on the exhaust pipe.

[0039] In a further embodiment, a vacuum pump and a flow regulating valve are installed on the gas pipeline. Specifically, the gas pipeline is located between the steam generator and the first-stage absorption bottle, and the vacuum pump and the flow regulating valve are sequentially installed in the direction of gas flow.

[0040] In this invention, the vacuum pump, flow regulating valve, and flow meter work together as a whole to regulate the flow rate in the gas path. The vacuum pump provides a stable pressure source, ensuring that the gas passes through the absorption bottle at a constant speed. This helps maintain the consistency of experimental conditions and reduces measurement errors caused by airflow fluctuations. By adjusting the power of the vacuum pump, the airflow speed can be controlled to be within the optimal range (e.g., 55–65 L / h), thereby improving the collection efficiency of the absorption bottle for the target gas (e.g., tritized water vapor). The flow regulating valve can adjust the airflow in real time according to experimental needs, ensuring that each experiment is conducted under optimal flow conditions. For example, the flow rate can be flexibly adjusted at different stages or for different samples to adapt to different collection requirements. The flow meter can display the instantaneous flow rate in real time, helping operators to understand the current airflow status at any time. The flow meter can also record the cumulative sampling flow rate, providing complete flow data for subsequent analysis and verification.

[0041] In a further embodiment, the absorption bottle contains ethylene glycol. Specifically, one end of the gas inlet pipe in the absorption bottle extends below the surface of the ethylene glycol liquid, while the other end of the gas outlet pipe is located above the surface of the ethylene glycol liquid.

[0042] The ethylene glycol used in this invention has high solubility for water vapor, effectively capturing moisture in gases, including tritium water vapor (HTO). Compared to pure water, ethylene glycol maintains high solubility over a wider temperature range, ensuring effective capture of target gases under various environmental conditions. Furthermore, ethylene glycol has a high boiling point and is less prone to evaporation, reducing the volatilization loss of the absorbent itself and ensuring stable capture performance over a long period. Ethylene glycol is relatively environmentally friendly, with simpler treatment and discharge processes, meeting stringent environmental standards and reducing the risk of environmental pollution.

[0043] It should also be noted that ethylene glycol is primarily used as a water vapor absorbent. However, other absorbents can be used in this invention to replace ethylene glycol, as long as they can effectively absorb water vapor. Ethylene glycol is preferred in this invention primarily because it has lower toxicity compared to some other organic solvents, resulting in less impact on human health. Even if a small amount of leakage occurs during operation, it will not cause serious harm to operators, thus increasing the safety factor. Furthermore, ethylene glycol is relatively environmentally friendly, with simpler treatment and discharge processes, meeting stringent environmental standards and reducing the risk of environmental pollution.

[0044] In a further embodiment, the sampled flow rate includes the instantaneous flow rate displayed by the flow meter and the cumulative sampled flow rate, wherein the instantaneous flow rate is 55–65 L / h and the cumulative sampled flow rate is 0.5–2 m³ / h. 3 .

[0045] This invention sets specific instantaneous flow rates (55-65 L / h) and cumulative sampling flow rates (0.5-2 m³ / h).3 This ensures consistent experimental conditions and reduces the influence of external factors on measurement results. Strict control of flow parameters allows for more accurate and reliable sampling efficiency data. Within this range, the absorption bottle can fully utilize its collection capacity, ensuring efficient collection of the target gas. Appropriate flow settings in this invention avoid incomplete collection due to excessively fast airflow or excessively slow sample retention time. Optimizing flow parameters minimizes sample loss and improves collection efficiency.

[0046] In a further embodiment, the sampling efficiency was measured to be above 99% by a measurement method.

[0047] The sampling efficiency in this invention is over 99%, meaning that almost all target gases (such as water vapor) are effectively captured in the absorption bottle, which makes the measurement results more accurate and reduces errors caused by sample loss.

[0048] Example 1

[0049] Embodiment 1 of this application provides a method for determining the sampling efficiency of a bubbling method tritium sampler. In the process of determining the sampling efficiency of the bubbling method tritium sampler, water vapor is generated by a steam generator to replace the use of standard tritium water with a known activity concentration to generate tritized water vapor (HTO) via bubbling. This effectively avoids the problem of difficulty in tracing the activity concentration of the generated tritized water vapor (HTO) and avoids the risk of contamination of the tritium sampler and sampler, as well as leakage of tritized water vapor (HTO), that may occur during efficiency determination using a tritized water vapor (HTO) gas source. The sampling efficiency of the bubbling method tritium sampler is calculated by weighing the water loss of the steam generator and the weight gain of the two-stage bubbler (absorption bottle) filled with ethylene glycol, and the ratio between the two values. This facilitates the determination of the sampling efficiency of the bubbling method tritium sampler and sampler.

[0050] like Figure 1 As shown, this embodiment provides a method for determining the sampling efficiency of a bubbling tritium sampler, including the following steps:

[0051] A three-stage bubbling apparatus is used, comprising a steam generator 1, a first-stage absorption bottle 4, and a second-stage absorption bottle 5. The steam generator 1 contains pure water and is used to generate steam during the heating process. The steam serves as the gas source and is introduced into the first-stage absorption bottle 4. One end of the first-stage absorption bottle 4 is connected to the steam generator 1 via a gas pipe, and the other end of the first-stage absorption bottle 4 is connected to one end of the second-stage absorption bottle 5. The other end of the second-stage absorption bottle 5 is connected to an exhaust pipe, on which a flow meter 7 is installed. The gas flow path is along the gas flow direction... A vacuum pump 2 and a flow regulating valve 3 are sequentially installed. Both the first-stage absorption bottle 4 and the second-stage absorption bottle 5 are filled with ethylene glycol 6 absorbent. One end of the gas pipe in the absorption bottle extends below the surface of the ethylene glycol 6 liquid, while the other end extends above the surface. The first-stage absorption bottle 4 and the second-stage absorption bottle 5 are connected in series for continuous sampling. The gas flow rate in each gas path is adjusted by the vacuum pump 2, the flow regulating valve 3, and the flow meter 7. During the experiment, the instantaneous sampling flow rate is 60 L / h, and the cumulative sampling flow rate is 0.5 m³ / h. 3 , until the measurement is completed.

[0052] After the measurement, the water was weighed using a calibrated balance. Finally, the weight loss of water in the steam generator 1 and the total weight gain of the first-stage absorption bottle 4 and the second-stage absorption bottle 5 filled with ethylene glycol absorbent were measured. The ratio of the two values ​​can be used to determine the collection efficiency of the two-stage absorption bottles for water vapor. This allows us to verify the sampler's efficiency in collecting water vapor and further validate its efficiency in collecting tritium water vapor.

[0053] Sampling efficiency = (weight gain of the first-stage absorption bottle + weight gain of the second-stage absorption bottle) / weight loss of the steam generator × 100%.

[0054] Example 2

[0055] The difference between this embodiment and Embodiment 1 is that the cumulative sampling flow rate is different; in this embodiment, the cumulative sampling flow rate is 1 m³ / s. 3 .

[0056] Example 3

[0057] The difference between this embodiment and Embodiment 1 is that the cumulative sampling flow rate is different; in this embodiment, the cumulative sampling flow rate is 1.5 m³ / s. 3 .

[0058] The sampling efficiency test data and results for Examples 1 to 3 are shown in Table 1.

[0059] Table 1

[0060]

[0061] As can be seen from Table 1, the present invention can ensure a sampling efficiency of over 99% under a specific cumulative sampling flow rate, indicating that the water vapor generated by the water vapor generator is almost entirely absorbed by the ethylene glycol in the first-stage and second-stage absorption bottles, which significantly improves the sampling efficiency.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 is that the sampling efficiency determination method used is different; this comparative example uses a traditional experimental measurement method.

[0064] Radioactive sampling and capture efficiency test method: Tritized water vapor is captured by absorbing three-stage bubblers connected in series. The first, second and third stage bubblers are absorption bottles filled with deionized water absorption liquid for continuous sampling. Finally, the tritium count in the three-stage bubblers is measured by liquid scintillation. The ratio of the tritium count in the first two stage bubblers to the tritium count in the third stage bubbler can be used to determine the capture efficiency of the two-stage bubblers for tritized water vapor.

[0065] The instantaneous flow rate sampled during the experiment was 60 L / h, and the cumulative sampling flow rate was measured at 5 m³ / h. 3 Under the given conditions, the water vapor sampling and collection efficiency was calculated. The experimental data are shown in Table 2.

[0066] Table 2 3 H sampling efficiency test data

[0067]

[0068] Comparative Example 2

[0069] The difference between this comparative example and Example 1 is that the sampling efficiency measurement method used is different; this comparative example uses the traditional theoretical calculation measurement method.

[0070] Theoretical calculations:

[0071] The HTO sampling efficiency of the bubbler was calculated and verified using the RVOsborne formula. The RVOsborne formula is shown in equations (1) and (2).

[0072] That is, the collection efficiency of the first-stage bubble flask for HTO is:

[0073]

[0074] The collection efficiency of HTO in the second-stage bubble flask is:

[0075]

[0076] In the formula: Assuming the relative humidity of the gas in the bubbler is H, then X represents the air moisture content (g / m³). 3 Y represents the saturated water content of air at the sampling temperature (g / m³). 3 ε is the saturation coefficient, which refers to the percentage of tritized water vapor in the bubbled air absorbed by the water in the bubbling flask; V is the volume of the sampled air; α is the isotope effect coefficient; A1 is the radioactivity (Bq) in the first-stage bubbler; A2 is the radioactivity (Bq) in the second-stage bubbler; C is the concentration of tritized water vapor HTO (Bq / m³). 3 m0 is the initial filling amount of the collecting liquid in the bubbler; m is the remaining amount of collecting liquid in the bubbler; X is the water content of the gas entering the bubbler.

[0077] By taking the saturation coefficient ε = 1 and the isotope effect coefficient α = 0.88 for the bubbler at a temperature of 20.6℃ and a relative humidity of 50%, the isotope effect coefficient increases with increasing temperature. However, in actual instrument sampling operations, the temperature of the bubbler is basically between 0℃ and 30℃, so the average value of 0.88 is taken. The calculation results are shown in Table 3.

[0078] Table 3 3 Theoretical calculation value of H sampling efficiency

[0079] Sample temperature (°C) Primary sparger efficiency (%) Secondary sparger efficiency (%) 20.6 76.2 96.6

[0080] As can be seen from Tables 2 and 3, the sampling efficiency of both traditional experimental measurements and theoretical calculations is lower than that of the weighing method in this invention. This indicates that the measurement method of this invention can avoid many errors present in the prior art and further improve the measurement accuracy.

[0081] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for determining the sampling efficiency of a bubbling tritium sampler, characterized in that, The process includes the following steps: gas generated by a steam generator is introduced into a tritium sampler, which includes multiple absorption bottles containing absorbent. The absorption bottles are connected in series. The first absorption bottle is connected to the steam generator via a gas pipeline. The gas pipeline is equipped with a vacuum pump and a flow regulating valve. The sampling flow rate in the gas path is controlled by a flow meter. After sampling, the sampling efficiency is the ratio of the mass gained by the tritium sampler to the mass lost by the steam generator.

2. The method for determining the sampling efficiency of a bubbling tritium sampler according to claim 1, characterized in that, The tritium sampler includes a first-stage absorption bottle and a second-stage absorption bottle connected in series. One end of the first-stage absorption bottle is connected to a steam generator through a gas pipe, and the other end of the first-stage absorption bottle is connected to one end of the second-stage absorption bottle. The other end of the second-stage absorption bottle is connected to an exhaust pipe, and a flow meter is installed on the exhaust pipe.

3. The method for determining the sampling efficiency of a bubbling tritium sampler according to claim 1, characterized in that, The absorbent is ethylene glycol.

4. The method for determining the sampling efficiency of a bubbling tritium sampler according to claim 1, characterized in that, The sampled flow rate includes the instantaneous flow rate displayed by the flow meter and the cumulative sampled flow rate, where the instantaneous flow rate is 55~65 L / h and the cumulative sampled flow rate is 0.5~2 m³ / h. 3 .

5. The method for determining the sampling efficiency of a bubbling tritium sampler according to claim 4, characterized in that, The instantaneous flow rate is 60 L / h, and the cumulative sampled flow rate is 1.5 m³. 3 .

6. The method for determining the sampling efficiency of a bubbling tritium sampler according to claim 2, characterized in that, Sampling efficiency = (weight gain of the first-stage absorption bottle + weight gain of the second-stage absorption bottle) / weight loss of the steam generator × 100%.

7. The method for determining the sampling efficiency of a bubbling tritium sampler according to claim 1, characterized in that, The sampling efficiency was measured to be over 99% using the specified method.

8. An apparatus for implementing the method for determining the sampling efficiency of a bubbling tritium sampler according to any one of claims 1-7, characterized in that, It includes a steam generator and a tritium sampler. The tritium sampler consists of multiple absorption bottles connected in series. The first absorption bottle is connected to the steam generator through a gas pipe, and the last absorption bottle is connected to the exhaust pipe.

9. The apparatus according to claim 8, characterized in that, A vacuum pump and a flow regulating valve are installed sequentially along the gas flow direction on the gas pipeline, and a flow meter is installed on the exhaust pipeline.

10. The apparatus according to claim 8, characterized in that, The gas pipe at one end of the absorption bottle, which allows gas to enter, extends below the surface of the ethylene glycol liquid, while the gas pipe at the other end, which discharges gas, is located above the surface of the ethylene glycol liquid.

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