Automatic sampling and measuring method for gaseous tritium

Abstract

The invention provides an automatic sampling and measuring method for gaseous tritium, which comprises the following steps: S1, sampling of tritium-containing gas: dissolving the tritium-containing gas in sampling liquid through a tritium-containing gas sampling unit to prepare tritium-containing liquid; s2, tritium-containing liquid sample preparation and sample feeding: tritium-containing liquid and scintillation liquid are proportionally injected into a measuring bottle through a tritium-containing liquid sample preparation unit, and then the moving position of the measuring bottle is controlled through a sample feeding operation unit; and S3, automatic measurement: measuring the flicker spectrum of the measurement bottle placed in an automatic measurement unit through the automatic measurement unit, and calculating the activity of tritium after measurement. According to the invention, automatic sampling, automatic sample preparation, automatic sample feeding and automatic measurement of tritium in air can be realized, automatic online monitoring of gaseous tritium is realized, and improvement of monitoring efficiency is facilitated; unattended operation and long-time full-automatic sampling and measurement of tritium in the atmospheric environment and gaseous effluent can be realized, and on-line monitoring of low-concentration tritium in air is realized; the system can be quickly started when a nuclear radiation accident occurs, and the response speed of nuclear emergency monitoring is improved.

Description

Technical Field

[0001] This invention relates to the field of environmental radiation measurement technology, and in particular to an automatic sampling and measurement method for gaseous tritium. Background Technology

[0002] tritium( 3 Tritium (H) is a radioactive element produced and released during the production process of nuclear power plants and nuclear fuel processing plants. It decays, releasing beta rays with a maximum energy of 18.6 keV and an average energy of 5.7 keV. Due to its low energy, beta rays have a short range in air, making measurement difficult. Current tritium measurement techniques mainly include:

[0003] (1) Ionization Chamber Method: A sampled gas containing gaseous tritium is passed into a tritium ionization chamber. The β particles produced by tritium decay interact with the medium within the chamber, causing ionization of the medium molecules and generating electron-ion pairs. A voltage is applied between the electrodes of the ionization chamber to create an electric field. Under the influence of this electric field, the generated positive and negative ions drift towards the negative and positive electrodes, respectively, forming an ionization current. The magnitude of the ionization current is proportional to the tritium activity. By measuring the magnitude of the ionization current, the tritium activity can be determined. Because background ionizing radiation exists in the air, a compensation ionization chamber is needed to eliminate the influence of background ionizing radiation and provide real-time monitoring capabilities.

[0004] (2) “Sampling + liquid scintillation measurement” method: First, gaseous tritium is converted into tritium water by catalytic oxidation. Then, tritium water in the air is collected by bubbling, condensation, freezing and adsorption methods to form a tritium-containing liquid sample. Finally, the sample is mixed with scintillation liquid and sent to an automatic measurement unit to measure the tritium activity. Finally, the concentration of tritium in the air is calculated based on the volume of collected air. This method has a low measurement limit, but it requires offline sampling, sample preparation and measurement, which leads to monitoring lag and cannot meet the requirements of online rapid response.

[0005] "Sampling + liquid flash measurement" is a common method for measuring low-level tritium concentrations in the air. The technologies involved mainly include tritium catalytic oxidation technology, tritized water collection technology, and tritium-containing liquid measurement technology.

[0006] Tritium catalytic oxidation technology uses a catalyst to react gaseous tritium (HT, T2) with oxygen at high temperatures to generate water tritide (HTO), making it easier for tritium in the air to be adsorbed and treated. The catalysts used are mainly metal oxide catalysts (such as copper oxide, cerium oxide, etc.) and noble metal catalysts (such as platinum, palladium, etc.).

[0007] Tritium water can be collected through various methods, including bubbling, condensation, freezing, and adsorption. Bubbling involves passing air through a collection system containing water or other non-aqueous solvents, allowing the tritium water vapor to be absorbed by the solvent, thus capturing the tritium water. Condensation uses a dehumidifier as a collector; airborne tritium (HTO) is drawn into the dehumidifier and condensed into liquid water, which is then collected directly from the dehumidifier's outlet. Freezing uses a cold trap (semiconductor, liquid nitrogen) as a collector; the sampled air passes through a cold trap cooled below its freezing point, freezing the HTO in the collection container. After sampling, a heating system melts the captured frozen water before collection. Drying uses a desiccant as a collector; HTO in the air is adsorbed as it passes through a desiccant adsorption column. Commonly used desiccants include silica gel, molecular sieves, anhydrous calcium sulfate, and activated alumina. The adsorbed HTO forms a hydrated compound with the adsorbent, requiring distillation or heating to desorb it before it can be used as a sample for measurement.

[0008] The basic principle of liquid scintillator spectrometry is based on the fluorescence effect generated by the interaction of radiation and matter. When radioactive particles emitted by a radioactive isotope collide with solvent molecules in the scintillator fluid, the solvent molecules absorb the radiation energy and transition to an excited state. Subsequently, during their return to the ground state, they transfer energy to the scintillator molecules. As the scintillator molecules return from the excited state to the ground state, they emit fluorescent photons. These fluorescent photons are received by a photomultiplier tube and converted into photoelectrons. After multiplication, they are collected at the anode and ultimately output as pulse signals. By coinciding, amplifying, analyzing, and displaying these pulse signals, the intensity and magnitude of radioactivity in the sample liquid can be reflected.

[0009] However, while ionization chambers can measure tritium concentration in the air in real time, their detection limit is relatively high (≥3.7 × 10⁻⁶). 4 Bq / m 3 This cannot meet the requirement of low concentration (≤1×10⁻⁶). 3 Bq / m 3 It has monitoring needs and is susceptible to interference from radon and cosmic rays.

[0010] While the "sampling + measurement" method can collect tritium in the air over a long period of time and has a low detection limit, the samples need to be collected, prepared, and sent to a liquid scintillation spectrometer for measurement. This method has a low degree of automation and cannot achieve online monitoring. Summary of the Invention

[0011] The purpose of this invention is to provide an automatic sampling and measurement method for gaseous tritium, which solves the problem that manual sampling, sample preparation and measurement are required when monitoring low concentrations of tritium in the air, which is labor-intensive and cannot achieve online monitoring.

[0012] This invention provides an automatic sampling and measurement method for gaseous tritium, comprising the following steps: S1 Tritium gas sampling, wherein tritium gas is dissolved in a sampling liquid using a tritium gas sampling unit to prepare a tritium-containing liquid, and the mixture is homogeneous; S2 Tritium-containing liquid sample preparation and delivery, wherein the tritium-containing liquid and scintillation fluid are mixed and added to a measurement bottle using a tritium-containing liquid sample preparation unit, and the measurement bottle is moved using a sample delivery operation unit; S3 Automatic measurement, wherein the scintillation spectrum of the measurement bottle placed therein is measured using an automatic measurement unit, and the tritium activity is calculated after the measurement.

[0013] Furthermore, in step S1, during tritium gas sampling, the tritium gas sampling unit converts gaseous tritium into water tritide through a tritium catalytic oxidation component, and then dissolves the water tritide in the sampling liquid through a tritium enrichment component.

[0014] Furthermore, in the tritium catalytic oxidation component, tritium-containing air is collected by a gas pump and sent into the catalytic oxidation furnace, where gaseous tritium is converted into tritized water.

[0015] Furthermore, in the tritium enrichment component, tritized water in the catalytic oxidation furnace is fed into the sampling bottle, and the gas in the sampling bottle is bubbled through a bubbler to dissolve the tritized water into the sampling liquid, thereby achieving tritium sampling and enrichment.

[0016] Furthermore, there are two sampling bottles, namely a first sampling bottle and a second sampling bottle connected in series along the tritium water path, and the first sampling bottle and the second sampling bottle are mixed through a sampling liquid mixing box.

[0017] Furthermore, in step S2, the preparation and delivery of tritium-containing liquid samples, in the tritium-containing liquid preparation unit, pure water is drawn from the pure water tank by a water pump and added to the first sampling bottle and the second sampling bottle respectively. After sampling, pure water is drawn from the pure water tank to rinse the sampling bottles, and the first sampling bottle and the second sampling bottle are mixed in the sampling liquid mixing tank.

[0018] Furthermore, in the tritium-containing liquid sample preparation unit, the first peristaltic pump draws liquid from the sampling bottle through the sampling liquid mixing tank and adds it to the scintillation measurement bottle, the second peristaltic pump draws scintillation liquid from the scintillation liquid storage tank and adds it to the scintillation measurement bottle, and the remaining mixed sampling liquid in the sampling liquid mixing tank is discharged into the waste liquid tank through the pipeline.

[0019] Furthermore, in the sample delivery unit, the operating gripper, driven by the linear guide rail, sequentially completes the following operations: gripping an empty measuring bottle from the measuring bottle grabbing position below the measuring bottle storage tank, unscrewing the bottle cap at the bottle cap operating position, adding scintillation liquid at the scintillation liquid filling position, adding tritium-containing liquid at the sampling liquid filling position, returning to the bottle cap operating position to tighten the bottle cap, shaking the measuring bottle, delivering the measuring bottle to the sample inlet of the automatic measuring unit, and releasing the gripper to allow it to fall into the automatic measuring unit.

[0020] Furthermore, in the automatic measurement unit, after the measuring bottle enters the sample inlet of the automatic measurement unit, the automatic measurement unit releases the measuring bottle support plate, allowing the measuring bottle to enter the measurement station, then closes the light-shielding cover, uses a photomultiplier tube to measure the scintillation spectrum, and calculates the tritium activity after the measurement is completed.

[0021] Furthermore, in the sample delivery unit, after the automatic measurement unit completes the measurement, the operating gripper, driven by the linear guide rail, sequentially completes the operations of picking up the measurement bottle from the sample inlet of the automatic measurement unit, reaching the measurement bottle collection position in the measurement bottle collection box, and releasing the gripper to fall into the measurement bottle collection box.

[0022] The technical solution of this invention achieves automatic sampling of tritium in the air to prepare a tritium-containing liquid using a tritium-containing gas sampling unit, which is then uniformly mixed. The tritium-containing liquid is then automatically prepared using a tritium-containing liquid sample preparation unit, and the sample delivery unit automatically delivers the prepared sample vial to the automatic measurement unit for measurement. Thus, this invention enables automatic sampling, sample preparation, sample delivery, and measurement of tritium in the air, eliminating reliance on manual operations for sample preparation and delivery, and achieving automatic online monitoring of gaseous tritium, thereby improving monitoring efficiency. It also enables unattended, long-term, fully automatic sampling and measurement of tritium in the atmospheric environment and gaseous effluents, achieving online monitoring of low concentrations of tritium in the air; and it can be quickly activated in the event of a nuclear radiation accident, improving the response speed of nuclear emergency monitoring. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is an overall schematic diagram of the present invention;

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-Air pump; 2-Flow meter; 3-Catalytic oxidation furnace; 4-First sampling bottle; 5-Second sampling bottle; 6-Bubbler; 7-Water pump; 8-Pure water tank; 9-First solenoid valve; 10-Sampling liquid mixing tank; 11-Scintillation liquid storage tank; 12-First peristaltic pump; 13-Second peristaltic pump; 14-Second solenoid valve; 15-Guide rail; 16-Slider; 17-Extension arm; 18-Measuring bottle storage tank; 19-Measuring bottle; 20-Rotating gripper; 21-Operating gripper; 211-Measuring bottle gripping position; 212-Bottle cap operating position; 213-Scintillation liquid filling position; 214-Sampling liquid filling position; 215-Automatic measurement unit inlet; 216-Measuring bottle collection position; 22-Measuring bottle collection box; 23-Waste liquid tank; 24-Automatic measurement unit. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Example 1

[0031] like Figure 1 As shown, the present invention provides an automatic sampling and measurement method for gaseous tritium, comprising the following steps: S1 Tritium gas sampling, wherein a tritium gas sampling unit is used to dissolve tritium gas in a sampling liquid to prepare a tritium liquid, and the liquid is mixed evenly in a sampling liquid mixing tank 10; S2 Tritium liquid sample preparation and delivery, wherein a tritium liquid and scintillation fluid are mixed and added to a measuring bottle 19 by a tritium liquid sample preparation unit; the measuring bottle 19 is moved by a sample delivery operation unit; S3 Automatic measurement, wherein an automatic measurement unit 24 measures the scintillation spectrum of the measuring bottle 19 placed therein, and the tritium activity is calculated after the measurement.

[0032] Specifically, the tritium-containing gas sampling unit can automatically sample tritium from the air to prepare a tritium-containing liquid, which is then uniformly mixed in a sampling liquid mixing tank 10. The tritium-containing liquid sample preparation unit can automatically prepare the sample, and the sample delivery unit can automatically deliver the prepared sample to a liquid scintillation spectrometer 19 for automatic measurement. Thus, this invention enables automatic sampling, sample preparation, sample delivery, and measurement of tritium in the air, eliminating reliance on manual operations for sample preparation and delivery, and achieving automatic online monitoring of gaseous tritium, thereby improving monitoring efficiency. It also enables unattended, long-term, fully automatic sampling and measurement of tritium in the atmospheric environment and gaseous effluents, achieving online monitoring of low concentrations of tritium in the air; and it can be quickly activated in the event of a nuclear radiation accident, improving the response speed of nuclear emergency monitoring.

[0033] Example 2

[0034] The tritium-containing gas sampling unit converts gaseous tritium into tritized water through a tritium catalytic oxidation component. The tritium catalytic oxidation component includes a gas pump 1, a flow meter 2, and a catalytic oxidation furnace 3 connected in sequence. The tritium-containing gas sampling unit dissolves the tritized water in the sampling liquid through a tritium enrichment component. The tritium enrichment component includes sampling bottles (4, 5) and a bubbler 6, with the bubbler 6 disposed inside the sampling bottles (4, 5).

[0035] Specifically, the gas pump 1 is used to deliver the gas to be measured into the system; the flow meter 2 is used to measure the gas flow rate; the catalytic oxidation furnace 3 is used to convert gaseous tritium (T2, HT) into tritized water; there are two sampling bottles, namely the first sampling bottle 4 and the second sampling bottle 5 connected in series along the tritized water path. The two sampling bottles (4, 5) are equipped with a bubbler 6. The gas passes through the bubbler 6 to dissolve the tritized water into the sampling liquid (pure water 8), thereby achieving the sampling and enrichment of tritium.

[0036] Example 3

[0037] The tritium-containing liquid sample preparation unit includes a water pump 7 and a pure water tank 8, which is connected to the sampling bottle (4, 5) via the water pump 7. The tritium-containing liquid sample preparation unit includes a first peristaltic pump 12, a second peristaltic pump 13, and a scintillation fluid storage tank 11. The sampling bottle (4, 5) is connected to the measuring bottle 19 via the first peristaltic pump 12, and the scintillation fluid storage tank 11 is connected to the measuring bottle 19 via the second peristaltic pump 13.

[0038] Specifically, water pump 7 is used to draw a certain amount of purified water 8 from purified water tank 8 and add it to the first sampling bottle 4 and the second sampling bottle 5 respectively. After sampling, a certain amount of purified water 8 is drawn from purified water tank 8 in 2-3 times to rinse the sampling bottles (4, 5). The first sampling bottle 4 and the second sampling bottle 5 are mixed through sampling liquid mixing tank 10 and controlled by the first solenoid valve 9. The first peristaltic pump 12 draws 8 ml of liquid from sampling bottles (4, 5) through sampling liquid mixing tank 10 and adds it to scintillation measurement bottle 19. The second peristaltic pump 13 is used to draw 12 ml of scintillation liquid from scintillation liquid storage tank 11 and add it to scintillation measurement bottle 19. The remaining mixed sampling liquid in sampling liquid mixing tank 10 is discharged into waste liquid tank 23 through pipeline and the second solenoid valve 14.

[0039] Example 4

[0040] The sample delivery unit includes a guide rail 15 and an operating gripper 21. The operating gripper 21 is mounted on an extension arm 17, which is movably mounted on the guide rail 15 via a slider 16. The linear guide rail 15 is driven by a motor screw mechanism. Within the operating range of the guide rail 15 and the operating gripper 21, there are a measuring bottle storage tank 18, a scintillation liquid filling port, a sampling liquid filling port, an automatic measuring unit inlet 215, and a measuring bottle collection box 22. The sample delivery unit also includes a rotating gripper 20, whose operating range is within the operating range of the operating gripper 21. The rotating gripper 20 is used to unscrew and tighten the cap of the measuring bottle 19.

[0041] Specifically, after tritium collection is completed, the operating gripper 21, driven by the linear guide rail 15, sequentially completes the following operations: gripping an empty measuring bottle 19 from the measuring bottle gripping position 211 below the measuring bottle storage tank 18; reaching the bottle cap operating position 212 (by rotating the gripper 20) to unscrew the bottle cap; reaching the scintillation liquid filling position 213 to fill the scintillation liquid; reaching the sampling liquid filling position 214 to fill the tritium-containing liquid; returning to the bottle cap operating position 212 (by rotating the gripper 20) to tighten the bottle cap; shaking the measuring bottle 19 (by operating the gripper 21); sending the measuring bottle 19 to the liquid scintillation spectrometer inlet; and releasing the gripper.

[0042] After the automatic measurement unit 24 completes the measurement, the operating gripper 21, driven by the linear guide rail 15, sequentially completes the operations of picking up the measurement bottle 19 from the sample inlet 215 of the automatic measurement unit, reaching the measurement bottle collection position 216 of the measurement bottle collection box 22, and releasing the gripper.

[0043] Example 5

[0044] The automatic measurement unit 24 is equipped with a support plate for the measurement bottle 19 and a light-shielding cover. After the measurement bottle 19 enters the sample inlet 215 of the automatic measurement unit, the automatic measurement unit 24 releases the support plate for the measurement bottle 19, allowing the measurement bottle 19 to enter the measurement station. Then, the light-shielding cover is closed, and the scintillation spectrum is measured using a photomultiplier tube. After the measurement is completed, the activity of tritium is calculated.

[0045] Specifically, the automatic measurement unit 24 uses an RLS400P liquid scintillation spectrometer with a measurement range of 1×10⁻⁶. 3 ~1×10 5 Bq / m 3 Detection efficiency ≥25%.

[0046] The complete measurement process of the automatic sampling and measurement method for gaseous tritium of this invention:

[0047] Tritium-containing air is collected by air pump 1 and sent to catalytic oxidation furnace 3. In catalytic oxidation furnace 3, gaseous tritium is converted into tritized water and further sent to sampling bottle. The gas in the sampling bottle is bubbled by bubbler 6 to dissolve the tritized water into the sampling liquid (pure water 8), thus achieving tritium sampling and enrichment. The first peristaltic pump 12 draws 8 ml of liquid from the sampling bottle and adds it to the scintillation measurement bottle 19; the second peristaltic pump 13 draws 12 ml of scintillation liquid from the scintillation liquid storage tank 11 and adds it to the scintillation measurement bottle 19. Driven by the linear guide rail 15, the operating gripper 21 picks up an empty measuring bottle 19 from below the measuring bottle storage tank 18, and carries the measuring bottle 19 to the cap operation position 212. The cap is then unscrewed by rotating the gripper 20, and the bottle is moved to the scintillation liquid filling position 213 to add scintillation liquid. Next, the bottle is moved to the sampling liquid filling position 214 to add tritium-containing liquid, and then back to the cap operation position 212. The cap is tightened by rotating the gripper 20, and the measuring bottle 19 is shaken to deliver it to the automatic measurement unit inlet 215. The gripper then releases the bottle, allowing it to fall into the automatic measurement unit 24. After the measuring bottle 19 enters the automatic measurement unit inlet 215, the scintillation spectrum is measured, and the tritium activity is calculated after the measurement. After the automatic measurement unit 24 completes the measurement, the operating gripper 21, driven by the linear guide rail 15, picks up the measuring bottle 19 from the automatic measurement unit inlet 215, and carries it to the measuring bottle collection box 22. The gripper then releases the bottle, allowing it to fall into the measuring bottle collection box 22.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic sampling and measurement method for gaseous tritium, characterized in that, Includes the following steps: S1 tritium gas sampling involves dissolving tritium gas in the sampling liquid using a tritium gas sampling unit to create a tritium-containing liquid, which is then thoroughly mixed. S2 Tritium-containing liquid sample preparation and delivery: The tritium-containing liquid and scintillation fluid are mixed and added to the measuring bottle through the tritium-containing liquid sample preparation unit, and the moving position of the measuring bottle is controlled by the sample delivery operation unit. The S3 automatic measurement unit measures the scintillation spectrum of the measurement bottle placed inside and then calculates the tritium activity.

2. The automatic sampling and measurement method for gaseous tritium according to claim 1, characterized in that, In step S1, during tritium gas sampling, the tritium gas sampling unit converts gaseous tritium into tritized water through a tritium catalytic oxidation component, and then dissolves the tritized water in the sampling liquid through a tritium enrichment component.

3. The automatic sampling and measurement method for gaseous tritium according to claim 2, characterized in that, In the tritium catalytic oxidation unit, tritium-containing air is collected by a gas pump and sent into the catalytic oxidation furnace, where gaseous tritium is converted into tritized water.

4. The automatic sampling and measurement method for gaseous tritium according to claim 3, characterized in that, In the tritium enrichment component, tritized water in the catalytic oxidation furnace is fed into the sampling bottle, and the gas in the sampling bottle is bubbled through a bubbler to dissolve the tritized water into the sampling liquid, thereby achieving tritium sampling and enrichment.

5. The automatic sampling and measurement method for gaseous tritium according to claim 4, characterized in that, There are two sampling bottles, namely the first sampling bottle and the second sampling bottle connected in series along the tritium water path. The first sampling bottle and the second sampling bottle are mixed through a sampling solution mixing box.

6. The automatic sampling and measurement method for gaseous tritium according to claim 5, characterized in that, In step S2, during the preparation and delivery of tritium-containing liquid samples, in the tritium-containing liquid sample preparation unit, purified water is drawn from the purified water tank by a water pump and added to the first sampling bottle and the second sampling bottle respectively. After sampling, purified water is drawn from the purified water tank to rinse the sampling bottles. The first sampling bottle and the second sampling bottle are then mixed in a sampling liquid mixing tank.

7. The automatic sampling and measurement method for gaseous tritium according to claim 6, characterized in that, In the tritium-containing liquid sample preparation unit, the first peristaltic pump draws liquid from the sampling bottle through the sampling liquid mixing tank and adds it to the scintillation measurement bottle. The second peristaltic pump draws scintillation liquid from the scintillation liquid storage tank and adds it to the scintillation measurement bottle. The remaining mixed sampling liquid in the sampling liquid mixing tank is discharged into the waste liquid tank through the pipeline.

8. The automatic sampling and measurement method for gaseous tritium according to claim 7, characterized in that, In the sample delivery unit, the operating gripper, driven by the linear guide rail, sequentially completes the following operations: gripping an empty measuring bottle from the measuring bottle grabbing position below the measuring bottle storage tank, unscrewing the bottle cap at the bottle cap operating position, adding scintillation liquid at the scintillation liquid filling position, adding tritium-containing liquid at the sampling liquid filling position, returning to the bottle cap operating position to tighten the bottle cap, shaking the measuring bottle, delivering the measuring bottle to the sample inlet of the automatic measuring unit, and releasing the gripper to allow it to fall into the automatic measuring unit.

9. The automatic sampling and measurement method for gaseous tritium according to claim 8, characterized in that, In the automatic measurement unit, after the measuring bottle enters the sample inlet of the automatic measurement unit, the automatic measurement unit releases the measuring bottle support plate, allowing the measuring bottle to enter the measurement station. Then, the light-shielding cover is closed, and the scintillation spectrum is measured using a photomultiplier tube. After the measurement is completed, the activity of tritium is calculated.

10. The automatic sampling and measurement method for gaseous tritium according to claim 9, characterized in that, In the sample delivery unit, after the automatic measurement unit completes the measurement, the operating gripper, driven by the linear guide rail, sequentially completes the operations of picking up the measurement bottle from the sample inlet of the automatic measurement unit, reaching the measurement bottle collection position in the measurement bottle collection box, and releasing the gripper to fall into the measurement bottle collection box.

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