Radon-tritium separation and tritium measurement system and method

Abstract

The present invention discloses a system and method for separating radon and tritium and measuring tritium, comprising: a first measuring unit, which comprises a catalyst, a drying tube, an ionization chamber I and an emission unit I connected in sequence through a pipeline; a second measuring unit, which comprises an equivalent device, an ionization chamber II and an emission unit II connected in sequence through a pipeline; wherein a gas sample containing radon and tritium is divided into two paths, one path enters the first measuring unit and generates a radon current signal in the ionization chamber I, and the other path enters the second measuring unit and generates a superimposed current signal of radon and tritium in the ionization chamber II, and the current signals of the ionization chambers I and II are collected and processed so that the output is only a tritium signal, and the tritium signal is processed to realize online monitoring and alarm of tritium. The present invention adopts tritium oxygen catalysis and gas-liquid separation technology to realize online real-time measurement of tritium; and realizes online monitoring of abnormal release of tritium under radon-containing atmosphere conditions.

Description

Technical Field

[0001] The present invention belongs to the field of radioactive radiation protection measurement technology, and specifically relates to a system and method for separating radon and tritium and measuring tritium. The method can be applied to the absolute measurement of tritium under high radon background, and timely provide real-time data of tritium concentration in the air under radon background. Background Art

[0002] Tritium is the only radioactive isotope of hydrogen. The maximum energy of the beta ray emitted by tritium decay is 18.6keV, and its average energy is 5.65keV. Tritium may corrode the containing material or cause degradation of material performance (brittle cracking, aging). Moreover, tritium can enter the human body through inhalation, ingestion, and penetration through intact skin, and be absorbed by human tissues and cause internal radiation hazards. Due to its radioactive hazards and its characteristics in the environment, the monitoring of tritium has received increasing attention in radiation protection monitoring. The measurement of high concentrations of tritium in the gas is all carried out using the ionization chamber method. The ionization chamber can measure a single radioactive ray (α, β, γ, n) of any radioactive nuclide, but the measurement of tritium cannot be measured separately under a high radon background. The measurement result is the sum of the radioactive intensities of radon and tritium, which makes the measurement of tritium under a high radon background a technical bottleneck.

[0003] The method of the present invention adopts ionization chamber measurement technology, and simultaneously combines catalytic oxidation detritium technology, gas drying technology and gas cleaning technology. The catalytic oxidation detritium technology is adopted to convert all the tritium therein into tritiated water; the drying tube drying technology is adopted to efficiently separate the gas and water in the airflow; the gas bubbling technology is adopted to clean the water vapor in the airflow, and the tritium component therein is completely collected, thereby realizing efficient radon-tritium separation and environmental protection. Summary of the invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] In order to achieve these purposes and other advantages according to the present invention, a system for separating radon and tritium and measuring tritium is provided, comprising:

[0006] A first measuring unit, which includes a catalyst, a drying tube, an ionization chamber I and an emission unit I connected in sequence through a pipeline;

[0007] A second measuring unit, which includes an equivalent device, an ionization chamber II and an exhaust unit II which are sequentially connected through a pipeline;

[0008] Among them, the gas sample containing both radon and tritium is divided into two paths. One path enters the first measuring unit and generates a radon current signal in ionization chamber I. The other path enters the second measuring unit and generates a superimposed current signal of radon and tritium in ionization chamber II. By collecting the current signals of ionization chamber I and ionization chamber II and superimposing them, the output is only a tritium signal. By processing the tritium signal, online monitoring and alarm of tritium can be achieved.

[0009] Preferably, the catalyst is a stainless steel tube with an inner diameter of Φ44mm×135mm, which contains a catalyst; the equivalent device is a stainless steel container; and the catalyst is Al2O3 plated with 1% Pd.

[0010] Preferably, the catalyst is arranged in an electric heating furnace, a spiral heating tube is arranged in the electric heating furnace, and the catalyst is placed in the spiral heating tube; an aluminum silicate fiber insulation layer is arranged on the electric heating furnace; and an armored thermocouple is inserted in the catalyst.

[0011] Preferably, the drying tube is a stainless steel jacket type drying tube, the inner tube of the drying tube transfers the tritium water from the catalyst to the outer tube of the drying tube, and the gas output from the inner tube is only the gas containing radon.

[0012] Preferably, the discharge unit I comprises:

[0013] A flow meter I, one end of which is connected to the gas outlet of the ionization chamber I through a pipeline, and the other end of which is connected to the inlet of the outer sleeve of the drying tube through a pipeline;

[0014] The bubbler is connected to the outlet of the outer sleeve of the drying tube through a pipeline; a solenoid valve I is arranged on the connecting pipeline between the bubbler and the outer sleeve of the drying tube; the outlet of the bubbler is sequentially connected to a buffer I, and two sets of parallel solenoid valves II and a vacuum pump I through a pipeline.

[0015] Preferably, the discharge unit I comprises:

[0016] A flow meter II has one end connected to the gas outlet of the ionization chamber I through a pipeline, and the other end connected to the inlet of the outer sleeve of the drying tube through a pipeline; the outlet of the outer sleeve of the drying tube is sequentially connected to the solenoid valve III, the buffer II, and two parallel sets of solenoid valves III and the vacuum pump II through a pipeline.

[0017] Preferably, the discharge unit II comprises:

[0018] The flow meter III has one end connected to the gas outlet of the ionization chamber II through a pipeline, and the other end connected to the inlet of the buffer I or the buffer II through a pipeline to be connected to the discharge unit I.

[0019] Preferably, it also includes:

[0020] A filter I for filtering the gas entering the catalyst and the equivalent device, which is connected to the inlet of the catalyst and the equivalent device through a pipeline; the inlet of the filter I is connected to the sampling tube interface;

[0021] Filter II is connected between the catalyst and the drying tube.

[0022] The present invention also provides a method for measuring using the above-mentioned radon-tritium separation and tritium measurement system, comprising the following steps:

[0023] The gas sample containing radon and tritium is divided into two paths. The first path enters the catalyst of the first measuring unit, catalyzes T2 in the gas containing radon and tritium into T2O, and then enters the drying tube. The inner tube of the drying tube migrates T2O to the outer tube of the drying tube. After T2 is removed from the inner tube of the drying tube, only the gas containing Rn enters the ionization chamber I. The high voltage polarity is negative, and the -I generated by radon is converted into Rn The signal is sent to the preamplifier circuit for superposition; the second gas enters the equivalent device and enters the ionization chamber II. The high voltage polarity is positive, and the gas in the ionization chamber II produces a superposition signal I of radon and tritium. Rn +I T , sent to the preamplifier circuit for signal superposition; after the preamplifier circuit superimposes the signals of ionization chamber I and ionization chamber II, the output is only the tritium signal, which is sent to the pre-microcurrent amplifier for amplification, and then AD conversion and numerical analysis are performed, and then displayed after calculation, so as to realize online monitoring and alarm of tritium; the gas passing through ionization chamber I and ionization chamber II is discharged through emission unit I and emission unit II.

[0024] Preferably, a programmable controller PLC is electrically connected to ionization chamber I and ionization chamber II to collect current signal data of ionization chamber I and ionization chamber II and perform data processing; a touch screen is used to display the data processing results of PLC after radon-tritium separation.

[0025] The present invention includes at least the following beneficial effects: the present invention adopts tritium-oxygen catalysis and gas-liquid separation technology to realize online real-time measurement of tritium; adopts PLC plus touch screen for automatic control and data processing, reduces manual intervention, improves measurement efficiency, and ensures work quality, and its purpose is to realize online monitoring of abnormal release of tritium under radon-containing atmosphere conditions.

[0026] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The structure principle diagram of the system for separating radon and tritium and measuring tritium of the present invention;

[0028] Figure 2This is a structural principle diagram of another radon-tritium separation and tritium measurement system of the present invention (using a bubbler);

[0029] Figure 3 This is a structural principle diagram of another radon-tritium separation and tritium measurement system of the present invention (without using a bubbler);

[0030] Figure 4 It is a structural principle diagram of another system for separating radon and tritium and measuring tritium of the present invention;

[0031] Figure 5 It is a front view of the three-dimensional structure of another system for separating radon and tritium and measuring tritium according to the present invention;

[0032] Figure 6 It is a rear view of the three-dimensional structure of another system for separating radon and tritium and measuring tritium according to the present invention;

[0033] Figure 7 A three-dimensional structural diagram of the catalyst of the radon-tritium separation and tritium measurement system of the present invention (without the electric heating furnace cover);

[0034] Figure 8 This is a schematic diagram of the drying tube tritium water vapor separation performance test system of the present invention;

[0035] Fig. 9 It is a structural principle diagram of the preamplifier circuit of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0037] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0038] Figure 1 A system for separating radon and tritium and measuring tritium according to the present invention is shown, comprising:

[0039] A first measuring unit, which includes a catalyst 3, a drying tube 5, an ionization chamber I 6 and an emission unit I 19 connected in sequence through a pipeline;

[0040] A second measuring unit, which includes an equivalent device 15, an ionization chamber II 16 and an exhaust unit II 20 connected in sequence through a pipeline;

[0041] Among them, the gas sample containing radon and tritium is divided into two paths, one path enters the first measuring unit and generates a radon current signal in the ionization chamber I, and the other path enters the second measuring unit and generates a superimposed current signal of radon and tritium in the ionization chamber II. By collecting the current signals of the ionization chamber I and the ionization chamber II and superimposing them, the output is only a tritium signal. By processing the tritium signal, online monitoring and alarm of tritium can be realized; the emission unit I19 and the emission unit II20 realize the emission of the gas passing through the ionization chamber I and the ionization chamber II.

[0042] In the above technical solution, the radon and tritium measurement principle is to first draw a gas sample containing radon and tritium (Rn+T2) into the ionization chamber II to generate a total linear current signal (I Rn +I T ), then separate the tritium and radon in the gas sample, and then draw the radon-containing gas into the ionization chamber I to generate a linear current signal of radon (I Rn ) The symmetrical ionization chamber I and ionization chamber II are exactly the same size, but the high voltage polarity is opposite. The signals generated by ionization chamber I and ionization chamber II are superimposed in the preamplifier circuit, and the total superimposed signal is Itotal = (I Rn +I T )-I Rn =I T , that is, the total superimposed signal is the tritium signal. After eliminating the influence of radon, the total signal enters the signal amplifier and data unit for processing, and the tritium concentration of the gas sample can be given in real time; Fig. 9 The circuit diagram of the preamplifier circuit is shown, in which A1 is a weak current amplifier, which performs current conversion and differential amplification on weak current; A2 is a single-ended to dual-ended amplifier, which converts single-ended signals into dual-ended signals; A3 is a mixer, which converts the signal frequency into the design frequency; A4 is an intermediate frequency amplifier, which amplifies the converted frequency signal again; A5 is a harmonic filter, which filters out the frequencies that do not need to be processed; A6 and A7 are low drift amplifiers, which amplify the signal; R1 is a feedback resistor, with low noise coefficient and current differential amplification; C1 is a feedback capacitor, and a π-type capacitor with high insulation impedance can be selected; C2, C3, and C4 are precision capacitors.

[0043] In the above technical solution, the catalyst is a stainless steel tube with an inner diameter of Φ44mm×135mm, which contains a catalyst; the equivalent device is a stainless steel container; the catalyst is Al2O3 plated with 1% Pd, which is used for catalytic oxidation to convert gaseous tritium into liquid tritium, and its conversion efficiency can reach more than 99%.

[0044] In the above technical solution, if Figures 5 to 7As shown, the catalyst 3 is arranged in an electric heating furnace 31, and a spiral heating tube 32 is arranged in the electric heating furnace 31, and the catalyst 3 is placed in the spiral heating tube 32; the electric heating furnace is provided with an aluminum silicate fiber insulation layer; an armored thermocouple 33 is inserted in the catalyst; considering the long-term use of the catalyst in this system, it is necessary to provide catalyst regeneration conditions, that is, it is necessary to configure a matching electric heating furnace, adopt a spiral heating tube heating method, the insulation resistance is above 5MΩ, and the heating power is about 1.5kw; an armored thermocouple is inserted in the center of the catalytic tube, which is convenient for measuring and controlling the working temperature of the catalyst, and the working temperature of the catalytic furnace is automatically collected and controlled by the armored thermocouple and PLC; the purpose of heating is mainly to prevent the surface of the catalyst from being covered with a water film and affecting the catalytic efficiency. Therefore, the heating temperature of the catalyst center can be maintained at about 100°C.

[0045] In the above technical solution, the drying tube 5 is a stainless steel jacket drying tube, which is a PD-50 stainless steel jacket drying tube produced by Perma Pure Inc. The inner tube of the drying tube transfers the tritium water from the catalyst to the outer tube of the drying tube, and the gas output from the inner tube is only the gas containing radon.

[0046] Preferably, if Figure 2 As shown, the discharge unit Ⅰ19 includes:

[0047] A flow meter Ⅰ 7, one end of which is connected to the gas outlet of the ionization chamber Ⅰ 6 through a pipeline, and the other end is connected to the inlet of the outer sleeve of the drying tube 5 through a pipeline; after the gas is dried by the drying tube, its water content is extremely low, and the gas coming out of the ionization chamber Ⅰ 6 can be used as a backwash gas to take away the water vapor in the outer sleeve of the drying tube;

[0048] The bubbler 12 is connected to the outlet of the outer sleeve of the drying tube 5 through a pipeline; a solenoid valve Ⅰ11 is provided on the connecting pipeline between the bubbler 12 and the outer sleeve of the drying tube 5; the outlet of the bubbler 12 is connected to the buffer Ⅰ10, and two sets of parallel solenoid valves Ⅱ13, 17 and vacuum pumps Ⅰ14, 18 in sequence through a pipeline; in this way, the gas-liquid flow rate in the pipeline is controlled by the flow meter Ⅰ, the vacuum pump Ⅰ is used as the power for the flow of gas and liquid in the whole system, and the buffer Ⅰ is used to stabilize the gas flow; the water vapor of the outer sleeve of the drying tube 5 is sent into the bubbler for bubbling, and the bubbler is pre-filled with bubbling liquid to efficiently collect the tritium water catalyzed by tritium gas; if an alarm event occurs, 1 mL of the bubbling liquid can be taken for tritium spectrum analysis using a liquid scintillation analyzer, thereby judging the accident identification and providing an accurate judgment basis for the emergency standby of the accident; in addition, the vacuum pump Ⅰ can be used as the power for the flow of gas and liquid in the whole system; the vacuum pump Ⅰ adopts the German Beker VT4.8 oil-free chip-selective vacuum pump, dual pumps work alternately; the solenoid valve adopts ZBS-1 high-end stainless steel solenoid valve.

[0049] In another technical solution, Figure 3 As shown, the discharge unit Ⅰ19 includes:

[0050] One end of the flow meter II 71 is connected to the gas outlet of the ionization chamber I 6 through a pipeline, and the other end is connected to the inlet of the outer sleeve of the drying tube 5 through a pipeline; the outlet of the outer sleeve of the drying tube 5 is connected to the solenoid valve III 8, the buffer II 101, and two parallel sets of solenoid valves III 131, 171 and vacuum pumps II 141, 181 in sequence through a pipeline. In this way, the gas-liquid flow rate in the pipeline is controlled by the flow meter II 71, the vacuum pump is used as the power for the gas and liquid flow of the entire system, and the buffer II is used to stabilize the gas flow.

[0051] In addition, if Figures 4 to 6 As shown, the above Figure 2 and 3 The two technical solutions are combined into one technical solution, and the electromagnetic valve III8, the electromagnetic valve I11 and the bubbler 12 can be connected in parallel. In the actual application process, the electromagnetic valve I11 or the electromagnetic valve III8 is opened to realize the process selection of using the bubbler and not using the bubbler. At the same time, the ionization chamber I and the ionization chamber II are existing commercially available ionization chambers, which are connected to the power box 61 and the high-voltage generator 62 to realize their working process.

[0052] In the above technical solution, if Figures 2 to 4 As shown, the discharge unit II comprises:

[0053] One end of the flow meter III 9 is connected to the gas outlet of the ionization chamber II 16 through a pipeline, and the other end is connected to the inlet of the buffer I 10 or the buffer II 101 through a pipeline and connected to the discharge unit I, so as to realize the process of the discharge unit II. By adopting this technical solution, the second gas passes through the ionization chamber II and then adopts the discharge unit I of the first gas, making the system structure more compact and saving costs.

[0054] The above technical solution also includes:

[0055] A filter Ⅰ2 for filtering the gas entering the catalyst 3 and the equivalent device 15, which is connected to the inlet of the catalyst 3 and the equivalent device 15 through a pipeline; the inlet of the filter Ⅰ2 is connected to the sampling tube interface 1; the filter Ⅰ can remove dust from the gas;

[0056] The filter II 4 is connected between the catalyst and the drying tube. The function of the filter II 4 is to filter the dust generated by the slight shedding and local pulverization of the catalyst coating in the catalyst.

[0057] The present invention also provides a method for measuring using the above-mentioned radon-tritium separation and tritium measurement system, comprising the following steps:

[0058] The gas sample containing radon and tritium is divided into two paths. The first path enters the catalyst of the first measuring unit, catalyzes T2 in the gas containing radon and tritium into T2O, and then enters the drying tube. The inner tube of the drying tube migrates T2O to the outer tube of the drying tube. After T2 is removed from the inner tube of the drying tube, only the gas containing Rn enters the ionization chamber I. The high voltage polarity is negative, and the -I generated by radon is converted into Rn The signal is sent to the preamplifier circuit for superposition; the second gas enters the equivalent device and enters the ionization chamber II. The high voltage polarity is positive, and the gas in the ionization chamber II produces a superposition signal I of radon and tritium. Rn +I T , sent to the preamplifier circuit for signal superposition; after the preamplifier circuit superimposes the signals of ionization chamber I and ionization chamber II, the output is only the tritium signal, which is sent to the pre-microcurrent amplifier for amplification, and then AD conversion and numerical analysis are performed, and then displayed after calculation to realize tritium online alarm monitoring; the gas passing through ionization chamber I and ionization chamber II is discharged into the laboratory local exhaust pipeline through emission unit I and emission unit II.

[0059] In the above technical solution, a programmable controller PLC is electrically connected to ionization chamber I and ionization chamber II to collect current signal data of ionization chamber I and ionization chamber II and perform data processing; a touch screen is used to display the results of radon and tritium separation after PLC data processing.

[0060] The technical core of the radon-tritium separation and tritium measurement system of the present invention is the catalytic reaction of the catalyst and the gas drying of the drying tube. The efficiency of the two is tested separately as follows:

[0061] Catalytic efficiency test of catalyst:

[0062] Will be equipped with 10 3 The Bq / L-level HT gas container is connected in series in front of the electric heating furnace with a built-in catalyst. The effective volume of the container is 1L. The electric heating furnace can continuously heat the catalytic reactor. Room air is used as the flushing gas, and the flow rate is controlled to 1L / min. The HT carried enters the catalytic reactor and is catalyzed into HTO. After passing through the drying tube, it enters the bubbler and is collected by the bubbling liquid. The bubbler is filled with 30mL of pure water bubbling liquid. After running for 60 minutes, it is stopped and 1mL of bubbling liquid is taken for measurement with a liquid scintillation analyzer to calculate the catalytic efficiency. Table 1 shows the test results of the catalytic efficiency;

[0063] Table 1

[0064]

[0065] As can be seen from Table 1, when the catalyst is at room temperature (20°C), the catalytic efficiency can reach 32%. When the catalyst is heated to 50°C, the catalytic efficiency reaches 95%, which has begun to rise. At 100°C, the catalytic efficiency is close to 100%, so it is appropriate to control the catalytic temperature within the range of 50°C to 110°C.

[0066] Drying tube tritium water vapor separation performance test:

[0067] The principle of the test system is shown in Figure 8 , add 50mL of tritiated water into the bubbler 111, and introduce argon gas from the carrier gas tank 116. By bubbling, at room temperature 20°C, tritiated water vapor with a relative humidity of 90% to 98% is generated. This is used as the experimental gas source, and its tritium concentration value is stable at 1.6×10 6 Bq / m 3 The tritiated water vapor is passed into the drying tube 112, and the flow meter 115 controls the flow rate at 1L / min. The outlet is connected to the 1# ionization chamber 113. After measurement, the gas enters the drying tube to flush the gas path, taking away the water vapor that penetrates the tube wall. The outlet is connected to the 2# ionization chamber 114 for monitoring the tritiated water vapor for comparison. Table 2 shows the separation performance test of the drying tube (Bq / m 3 )

[0068] Table 2

[0069] Serial number Test time (min) 2# Ionization Chamber 1# Ionization Chamber 1 0 <![CDATA[1.6×10 5 ]]> <![CDATA[1.62×10 5 ]]> 2 20 <![CDATA[7.4×10 5 ]]> <![CDATA[1.63×10 5 ]]> 3 40 <![CDATA[9.7×10 5 ]]> <![CDATA[1.58×10 5 ]]> 4 60 <![CDATA[1.1×10 6 ]]> <![CDATA[1.49×10 5 ]]> 5 120 <![CDATA[1.1×10 6 ]]> <![CDATA[1.61×10 5 ]]>

[0070] The test results show that the drying tube has a good separation effect on tritium water vapor. Since it takes about 20 minutes for tritiated water vapor to pass through the sulfonic acid wall of the drying tube, the waiting time for tritium identification under high radon background in the future should be no less than 20 minutes, and complete penetration takes about 60 minutes, which is the time required for the bubbler to run for tritium identification under high radon background for quantitative analysis of tritium identification.

[0071] It can also be seen from Table 2 that the tritiated water vapor cannot reach the outlet of the drying tube, and the reading of the No. 1 ionization chamber is always at the background level for up to 60 minutes.

[0072] Drying tube tritium permeability test:

[0073] System like Figure 8 As shown, no bubbling liquid was added to the bubbler, and the sampling flow rate was 1L / min. Argon was used as the drying tube flushing gas, the flow rate was controlled at 1L / min, and the test time was 140min. The results are shown in Table 3 Drying tube tritium permeability test (Bq / m 3 );

[0074] Table 3

[0075] Serial number Test time (min) 2# Ionization Chamber 1# Ionization Chamber 1 0 <![CDATA[1.4×10 5 ]]> <![CDATA[1.67×10 5 ]]> 2 10 <![CDATA[1.4×10 5 ]]> <![CDATA[1.63×10 5 ]]> 3 20 <![CDATA[9.3×10 5 ]]> <![CDATA[1.64×10 5 ]]> 4 30 <![CDATA[3.5×10 6 ]]> <![CDATA[1.60×10 5 ]]> 5 40 <![CDATA[1.1×10 7 ]]> <![CDATA[1.59×10 5 ]]> 6 50 <![CDATA[7.6×10 7 ]]> <![CDATA[1.63×10 5 ]]> 7 60 <![CDATA[1.5×10 7 ]]> <![CDATA[1.59×10 5 ]]> 8 70 <![CDATA[2.4×10 7 ]]> <![CDATA[1.66×10 5 ]]> 9 80 <![CDATA[1.3×10 7 ]]> <![CDATA[1.58×10 5 ]]> 10 90 <![CDATA[9.3×10 7 ]]> <![CDATA[1.66×10 5 ]]> 11 100 <![CDATA[5.2×10 6 ]]> <![CDATA[1.60×10 5 ]]> 12 110 <![CDATA[3.1×10 6 ]]> <![CDATA[1.61×10 5 ]]> 13 120 <![CDATA[8.4×10 5 ]]> <![CDATA[1.65×10 5 ]]> 14 130 <![CDATA[7.7×10 5 ]]> <![CDATA[1.62×10 5 ]]> 15 140 <![CDATA[4.6×10 5 ]]> <![CDATA[1.64×10 5 ]]>

[0076] The test results show that the tritium concentration in the dryer flushing airflow does not exceed the background and HT cannot pass through the inner tube of the dryer.

[0077] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A system for separating radon and tritium and measuring tritium, characterized in that: include: a first measuring unit comprising a catalyst, a drying tube, an ionization chamber I and an emission unit I connected in sequence through a pipeline; a second measuring unit comprising an equivalent device, an ionization chamber II and an exhaust unit II connected in sequence through a pipeline; The gas sample containing both radon and tritium is divided into two paths. One path enters the first measurement unit and generates a radon current signal in ionization chamber I. The other path enters the second measurement unit and generates a superimposed current signal of radon and tritium in ionization chamber II. By collecting the current signals of ionization chambers I and II and superimposing them, only the tritium signal is output. By processing the tritium signal, online monitoring and alarm of tritium can be achieved. The drying tube is a stainless steel outer jacket type drying tube. The inner tube of the drying tube transfers the tritium water from the catalyst to the outer jacket of the drying tube, and the gas output from the inner tube is only the gas containing radon. The discharge unit I comprises: Flow meter I, one end of which is connected to the gas outlet of ionization chamber I through a pipeline, and the other end of which is connected to the inlet of the outer sleeve of the drying tube through a pipeline; A bubbler is connected to the outlet of the outer sleeve of the drying tube through a pipeline; a solenoid valve I is provided on the connecting pipeline between the bubbler and the outer sleeve of the drying tube; the outlet of the bubbler is sequentially connected to a buffer I, and two parallel sets of solenoid valves II and a vacuum pump I through a pipeline; The discharge unit I comprises: A flow meter II, one end of which is connected to the gas outlet of the ionization chamber I via a pipe, and the other end is connected to the inlet of the outer sleeve of the drying tube via a pipe; the outlet of the outer sleeve of the drying tube is sequentially connected to the solenoid valve III, the buffer II, and two parallel sets of solenoid valves III and the vacuum pump II via pipes; The discharge unit II includes: The flow meter III has one end connected to the gas outlet of the ionization chamber II through a pipeline, and the other end connected to the inlet of the buffer I or the buffer II through a pipeline to be connected to the discharge unit I.

2. The radon-tritium separation and tritium measurement system according to claim 1, characterized in that: The catalyst is a stainless steel tube with an inner diameter of Φ44mm×135mm, which contains a catalyst; the equivalent device is a stainless steel container; and the catalyst is Al2O3 plated with 1% Pd.

3. The radon-tritium separation and tritium measurement system according to claim 2, characterized in that: The catalyst is arranged in an electric heating furnace, which is provided with a spiral heating tube, and the catalyst is placed in the spiral heating tube; an aluminum silicate fiber insulation layer is provided on the electric heating furnace; and an armored thermocouple is inserted in the catalyst.

4. The radon-tritium separation and tritium measurement system according to claim 1, characterized in that: Also includes: A filter I for filtering the gas entering the catalyst and the equivalent device, which is connected to the inlet of the catalyst and the equivalent device through a pipeline; The inlet of the filter I is connected to the sampling tube interface; Filter II is connected between the catalyst and the drying pipe.

5. A method for measuring using the system for separating and measuring radon and tritium according to any one of claims 1 to 4, characterized in that: The following steps are involved: The gas sample containing radon and tritium is divided into two paths. The first path enters the catalyst of the first measuring unit, catalyzes the T2 in the gas containing radon and tritium into T2O, and then enters the drying tube. The inner tube of the drying tube transfers T2O to the outer tube of the drying tube. After T2 is removed from the inner tube of the drying tube, only the gas containing Rn enters the ionization chamber I. The high voltage polarity is negative, and the -I generated by radon is converted into Rn The signal is sent to the preamplifier circuit for superposition; The second gas enters the equivalent device and enters the ionization chamber II. The high voltage polarity is positive. The gas in the ionization chamber II generates a superposition signal I of radon and tritium. Rn +I T , sent to the preamplifier circuit for signal superposition; after the preamplifier circuit superimposes the signals of ionization chamber I and ionization chamber II, the output is only the tritium signal, which is sent to the preamplifier for amplification, and then AD conversion and numerical analysis are performed, and the signal is displayed after calculation to realize online monitoring and alarm of tritium; the gas passing through ionization chamber I and ionization chamber II is discharged through emission unit I and emission unit II.

6. The method according to claim 5, wherein A programmable controller (PLC) is electrically connected to ionization chamber I and ionization chamber II to collect current signal data of ionization chamber I and ionization chamber II and perform data processing; a touch screen is used to display the data processing results of the PLC after radon and tritium separation.

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