A device and method for radon and tritium separation and discrimination measurement in a high radon environment

Abstract

The present application relates to the technical field of nuclear radiation detection, and particularly relates to a radon-tritium separation discrimination measurement device and method in a high-radon environment, which comprises a first measurement channel, a second measurement channel, a third measurement channel and a fourth measurement channel, and respectively measures a first current value I1, a second current value I2, a third current value I3 and a fourth current value I4, and respectively calculates the activity concentration C Rn of radon Rn, the activity concentration C HTO of tritiated water HTO and the activity concentration C HT of tritium gas HT according to the first current value I1, the second current value I2, the third current value I3 and the fourth current value I4. The present application focuses on the characteristics of indoor environment, considers the influence of indoor radon on tritium measurement, adopts a series-parallel differential mode, avoids the low detection limit influence caused by multi-channel measurement, is more suitable for low-concentration-level environment measurement, saves the need of purging gas, and simplifies the device structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear radiation detection, and particularly relates to a radon and tritium separation and discrimination measurement device and method in a high-radon environment. BACKGROUND

[0002] Tritium is a radioactive isotope of hydrogen, which emits beta rays when it decays spontaneously. In the ambient air, it mainly exists in the form of tritiated water vapor HTO and tritium gas HT, and a small amount exists in the form of tritiated methane CH3T. For a heavy tritium-related work site, when a large amount of tritium gas leaks, there will be a high activity concentration of HTO, HT and other different components of tritium in the local air. If it is inhaled into the body through the respiratory system, it can cause internal radiation damage. The radiation hazard ratio of HTO and HT is as high as 10000:1. Therefore, when different components of tritium sources exist at the same time, tritium discrimination measurement should be carried out to provide a scientific and reasonable basis for radiation protection of tritium-related workers and environmental safety evaluation. In addition, radon Rn is a naturally occurring alpha-emitting gas, which is commonly found in enclosed spaces and underground buildings, and can greatly interfere with the measurement of tritium in the place. Therefore, to achieve accurate measurement of tritium, the problem of radon and tritium separation and discrimination measurement in a high-radon environment must be solved.

[0003] There are methods for discriminating gaseous compounds related to tritium in the prior art, including drying method, bubbling method, condensation method, etc. These technologies or methods have the following problems: a. The device of the prior art mainly solves the discrimination measurement of tritium-related mixed gas in the outdoor environment, which is good for the discrimination measurement of tritium-related gas with high activity concentration, but the discrimination measurement effect of tritium-related mixed gas in indoor environment, especially in enclosed indoor environment, is limited, and it is not suitable for sampling of tritium-related gas with environmental background level; b. The prior art only aims at the discrimination measurement of tritium-related compounds, and does not solve the discrimination measurement of tritiated water HTO and tritium gas HT in a high-radon Rn environment, and the separation and discrimination measurement of radon Rn itself in tritium-related mixed gas; c. The prior art collects water samples by drying method, and the adsorption capacity is small, and there is a memory effect. The desorption process is time-consuming and complicated to operate; d. The prior art takes a long time to sample by using a series connection type atmospheric sampling device, and there is cross contamination between the sampling channels. There is a safety hazard in using a methane steel cylinder to provide CH4.

[0004] The prior art cannot meet the separation and discrimination measurement of radon and tritium-related gas in a high-radon environment, and the degree of automation of the device is low. The workers in the underground enclosed or low-level enclosed nuclear facilities storage space are at a high risk of radiation from radon and / or tritium-related gas. In order to solve the separation and discrimination measurement of radon and tritium-related gas in a high-radon environment, it is necessary to provide a radon and tritium separation and discrimination measurement device and method in a high-radon environment, which solves the separation and discrimination measurement of radon, tritium-related gas, and radon and tritium-related mixed gas in a high-radon environment. SUMMARY

[0005] The radioactive air environment forms in the underground closed or low-layer closed nuclear facilities mainly include: high-activity concentration radon Rn and tritiated water HTO, tritium gas HT mixed gas, high-activity concentration radon Rn and low-activity concentration tritiated water HTO, tritium gas HT mixed gas, low-activity concentration radon Rn and high-activity concentration tritiated water HTO, tritium gas HT mixed gas, and low-activity concentration radon Rn and tritiated water HTO, tritium gas HT mixed gas. The radioactive hazard of radon mainly reflects alpha rays, and the radioactive hazard of tritium gas mainly reflects beta rays. The separation and discrimination measurement of radon and tritium in the high-radon environment needs to use physical, chemical or physical and chemical mixed methods to judge the radiation hazards of radon and tritium in the high-radon environment. In view of the above analysis, the present application aims to provide a radon and tritium separation and discrimination measurement device and method in a high-radon environment, which separates and discriminates the radon Rn and tritiated water HTO, tritium gas HT in the high-radon environment, and provides a scientific and reasonable basis for the radiation protection of staff and the environmental safety evaluation.

[0006] The present application provides a radon and tritium separation and discrimination measurement device in a high-radon environment, which comprises: a first measurement channel, a second measurement channel, a third measurement channel and a fourth measurement channel, which respectively measure first current value I1, second current value I2, third current value I3 and fourth current value I4, and according to the first current value I1, the second current value I2, the third current value I3 and the fourth current value I4, the activity concentration C Rn of radon Rn, the activity concentration C HTO of tritiated water HTO and the activity concentration C HTThe first measuring path comprises: the input end of the electromagnetic valve and the output end of the sample gas are connected, the output end is connected with the input end of the filter through a connecting pipeline, the output end of the filter is connected with the input end of the first ionization chamber, the data I / O end of the first ionization chamber is connected with the programmable logic controller to collect the first current value I1; the second measuring path comprises: the output end of the first ionization chamber of the first measuring path is connected with the first HTO separation device through a connecting pipeline, the output end of the first HTO separation device is connected with the input end of the second ionization chamber through a connecting pipeline, the data I / O end of the second ionization chamber is connected with the programmable logic controller to collect the second current value I2; the third measuring path comprises: the output end of the second ionization chamber of the second measuring path is connected with the first port of the first three-way electromagnetic valve through a connecting pipeline; the second port of the first three-way electromagnetic valve is connected with the input end of the first dynamic balance valve through a connecting pipeline, the output end of the first dynamic balance valve is connected with the input end of the third ionization chamber, the output end of the third ionization chamber is connected with the first flow meter, the data I / O end of the third ionization chamber is connected with the programmable logic controller to collect the third current value I3; the fourth measuring path comprises: the third port of the first three-way electromagnetic valve of the third measuring path is connected with the input end of the second dynamic balance valve through a connecting pipeline, the output end of the second dynamic balance valve is connected with the input end of the HT catalytic device through a connecting pipeline, the output end of the HT catalytic device is connected with the input end of the second HTO separation device through a connecting pipeline, the output end of the second HTO separation device is connected with the input end of the fourth ionization chamber through a connecting pipeline, the data I / O end of the fourth ionization chamber is connected with the programmable logic controller to collect the fourth current value I4; the output end of the fourth ionization chamber is connected with the second flow meter, the heating belt and the dryer in sequence through connecting pipelines, the output end of the dryer is connected with the first port of the third three-way electromagnetic valve, the second port of the third three-way electromagnetic valve is connected with the electronic vacuum gauge and the vacuum pump, the third port of the third three-way electromagnetic valve is connected with the collection bottle; the output end of the first flow meter is connected with the input end of the bubbler, the output end of the bubbler is connected with the first port of the second three-way electromagnetic valve, the second port of the second three-way electromagnetic valve is connected with the electronic vacuum gauge and the vacuum pump, and the third port of the second three-way electromagnetic valve is connected with the collection bottle.

[0007] Preferably, the control ends of the vacuum pump, the electromagnetic valve, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve, the second dynamic balance valve, the dryer and the heating belt are connected with the programmable logic controller, the data I / O ends of the first ionization chamber, the second ionization chamber, the third ionization chamber and the fourth ionization chamber are connected with the programmable logic controller, and the programmable logic controller is connected with the computer module through a communication port.

[0008] The preferred technical solution is to calculate the activity concentration C of radon Rn. Rn The activity concentration C of HTO in tritium-treated water HTO Activity concentration C of tritium (HT) HT The formulas are as follows: Radon Rn activity concentration C Rn The formula is: In equation (A1), I4 is the current value measured in the fourth ionization chamber, and E α Radon gas R n The energy of the decaying alpha particle, C Rn Radon R in the mixed gas n Concentration, V is the sensitive volume of the fourth ionization chamber, The average ionization energy required to produce a pair of ions from an alpha particle; where the activity concentration C of tritium (HT) is... HT The formula is: In equation (A2), I3 is the current value measured in the third ionization chamber; E β C is the energy of the β particle from the decay of tritium (HT). HT The concentration of tritium (HT) in the mixed gas; the activity concentration (C) of tritium-treated water (HTO). HTO for: In equation (A3), I1 is the current value measured in the first ionization chamber, I2 is the current value measured in the second ionization chamber, and E β C is the energy of the β particle from the decay of tritium (HT). HTO The concentration of water tritium (HTO) in the mixed gas. The average ionization energy required to produce a pair of ions for a β particle.

[0009] The preferred technical solution is as follows: the dryer is a dual-tube structure, including a first Nafion dryer and a second Nafion dryer. The sample gas enters from the input end of the first Nafion dryer and exits from the output end of the second Nafion dryer. A temperature and flow controller is provided at the inlet of the purge gas path of the second Nafion dryer to control the temperature and flow rate of the purge gas.

[0010] The preferred technical solution is as follows: the HT catalytic device comprises: the HT catalytic device is composed of catalytic boxes with two to six graded density gradients, the HT catalytic device uses Al2O3 plated with 1% palladium as the catalytic material of the HT catalytic device catalytic box, and the mass and distribution density of the catalytic material of each graded catalytic box increases sequentially from the gas inlet to the gas outlet.

[0011] The preferred technical solution is that the first ionization chamber, the second ionization chamber, the third ionization chamber, and the fourth ionization chamber are cancellation compensation ionization chambers.

[0012] The preferred technical solution is that the programmable logic controller is a UNC host or an industrial control computer.

[0013] Preferably, the filter is a glass fiber filter membrane or a multi-layer filter membrane kit.

[0014] The application further discloses a radon-tritium separation and discrimination measurement method in a high-radon environment, which is applied to the radon-tritium separation and discrimination measurement device in the high-radon environment and comprises the following steps: 101, setting test environment parameters and condition thresholds of control instructions of a vacuum pump, an electromagnetic valve, a first three-way electromagnetic valve, a second three-way electromagnetic valve, a third three-way electromagnetic valve, a first dynamic balance valve, a second dynamic balance valve, a dryer and a heating belt through a computer module, and sending the condition thresholds to a programmable logic controller; 102, starting, purifying a pipeline environment, controlling the electromagnetic valve of sample gas to be closed, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve and the second dynamic balance valve to be in an open state through the programmable logic controller; 103, controlling the vacuum pump to start through the programmable logic controller, and controlling the vacuum pump to stop when vacuum parameters RH and humidity parameters δ meet vacuum conditions δ1 and humidity conditions RH1, that is, δ ≤ δ1 and RH ≤ RH1, and recording humidity parameters δ1 and vacuum parameters RH1; 104, controlling the heating belt to be heated to t through the programmable logic controller, and stopping heating when t ≥ t1; 105, controlling the second three-way electromagnetic valve and the third three-way electromagnetic valve connected with an electronic vacuum gauge and the vacuum pump to be closed through the programmable logic controller; 106, controlling the electromagnetic valve of sample gas to be opened and inputting a gas to be measured through the programmable logic controller; 107, controlling the electromagnetic valve, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve and the second dynamic balance valve to be closed according to a time threshold of separation and discrimination measurement through the programmable logic controller, and recording a first current value I1 of a first ionization chamber, a second current value I2 of a second ionization chamber, a third current value I3 of a third ionization chamber and a fourth current value I4 of a fourth ionization chamber; 108, calculating the activity concentration C Rn of radon Rn, the activity concentration C HTO of tritiated water HTO, the activity concentration C HT of tritium gas HT and the activity concentration C Rn of radon Rn according to the first current value I1, the second current value I2, the third current value I3 and the fourth current value I4 respectively, and the formula is as follows: In the formula (A1), I4 is a current value measured by the fourth ionization chamber, E α is an α particle energy of radon R n decay, C Rn is a radon R n concentration in a mixed gas, and V is a sensitive volume of the fourth ionization chamber, is an average ionization energy required for an α particle to generate a pair of ion pairs; wherein the formula of the activity concentration C HT of tritium gas HT is as follows: (A2), In equation (A2), I3 is the current value measured in the third ionization chamber; E β C is the energy of the β particle from the decay of tritium (HT). HT The concentration of tritium (HT) in the mixed gas; the activity concentration (C) of tritium-treated water (HTO). HTO for: In equation (A3), I1 is the current value measured in the first ionization chamber, I2 is the current value measured in the second ionization chamber, and E β C is the energy of the β particle from the decay of tritium (HT). HTO The concentration of water tritium (HTO) in the mixed gas. The average ionization energy required to produce a pair of ions for a β particle; 109: reset.

[0015] The beneficial effects of this invention are:

[0016] 1. This invention focuses on the characteristics of indoor environments and considers the impact of indoor radon gas on tritium measurement. By connecting the first, second, third, and fourth measurement paths in a differential series-parallel mode, it avoids the challenge of low detection limits caused by multi-channel measurement, is more suitable for measurement in low-concentration environments, saves the need for purge gas, and simplifies the device structure.

[0017] 2. The drying tube of this invention adopts a dual-tube mode, which further improves the separation performance and solves the problem of small adsorption capacity of a single tube. At the same time, compared with semiconductor gradient cold trap, the Nafion dryer is cheaper, more cost-effective, and easier to maintain.

[0018] 3. The first ionization chamber, second ionization chamber, third ionization chamber and fourth ionization chamber of the present invention adopt a high-precision tritium measurement chamber with cancellation compensation, which reduces the influence of memory effect and environmental γ on the measurement of low concentration tritium, and further improves the measurement accuracy. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of the radon-tritium separation and identification measurement device under high radon conditions according to the present invention;

[0021] Figure 2 This is a schematic diagram of the Nafion dryer 12 in the radon-tritium separation and identification measurement device under high radon conditions of the present invention;

[0022] Figure 3 This is a schematic diagram of the HT catalytic device 11 of the radon-tritium separation and identification measurement equipment under high radon conditions of the present invention.

[0023] In the drawings, the meaning of the reference numerals is as follows: including:

[0024] 1 …… vacuum pump, 2 …… electronic vacuum gauge, 3 …… electromagnetic valve, 4 …… filter, 51 …… first ionization chamber, 52 …… second ionization chamber, 53 …… third ionization chamber, 54 …… fourth ionization chamber, 61 …… first HTO separation device, 62 …… second HTO separation device, 71 …… first three-way electromagnetic valve, 72 …… second three-way electromagnetic valve, 73 …… third three-way electromagnetic valve, 81 …… first dynamic balance valve, 82 …… second dynamic balance valve, 91 …… first flow meter, 92 …… second flow meter, 10 …… bubbler, 11 …… HT catalytic device, 111 …… first, second and third catalytic boxes, 112 …… electric heating wire, 113 …… input port of HT catalytic device, 114 …… output port of HT catalytic device, 12 …… dryer, 121 …… first Nafion dryer, 122 …… second Nafion dryer, 1211 …… input port of first Nafion dryer, 1221 …… output port of second Nafion dryer, 1222 …… temperature flow controller, 13 …… heating belt, 14 …… temperature sensor, 15 …… humidity sensor, 16 …… programmable logic controller, 17 …… computer module, 18 …… power supply module for each electrical device, 19 …… pipe, 20 …… collection bottle, 100 …… first measurement channel, 200 …… second measurement channel, 300 …… third measurement channel, 400 …… fourth measurement channel DETAILED DESCRIPTION

[0025] The application will be described in further detail below with reference to the drawings. Like elements in different embodiments are denoted by like reference numerals. In the following embodiments, many details are described in order to provide a better understanding of the application. However, a person skilled in the art can easily recognize that some features can be omitted in different cases, or can be replaced by other elements, materials or methods. In some cases, some operations related to the application are not shown or described in the specification in order to avoid the core of the application being overwhelmed by too much description, and it is not necessary to describe these related operations in detail for a person skilled in the art based on the description in the specification and general technical knowledge in the art.

[0026] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0027] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). Detailed Implementation Method 1

[0029] As attached Figure 1 As shown: This invention provides a radon-tritium separation and identification measurement device under high radon environment, comprising: a vacuum pump 1, an electronic vacuum gauge 2, a solenoid valve 3, a filter 4, a first ionization chamber 51, a second ionization chamber 52, a third ionization chamber 53, a fourth ionization chamber 54, a first HTO separation device 61, a second HTO separation device 62, a first three-way solenoid valve 71, a second three-way solenoid valve 72, a third three-way solenoid valve 73, a first dynamic balancing valve 81, a second dynamic balancing valve 82, a first flow meter 91, a second flow meter 92, a bubbler 10, an HT catalytic device 11, a dryer 12, a heating belt 13, a temperature sensor 14, a humidity sensor 15, a programmable logic controller 16, a computer module 17, power supply modules for various electrical devices 18, pipelines 19, and a collection bottle 20.

[0030] Based on the measured first current value I1, second current value I2, third current value I3 and fourth current value I4, they can be divided into: first measurement path 100, second measurement path 200, third measurement path 300 and fourth measurement path 400.

[0031] The first measurement path 100 includes: the input end of the solenoid valve 3 is connected to the output end of the sample gas, the output end of the solenoid valve 3 is connected to the filter 4 through the pipe 19, the filter 4 is connected to the input end of the first ionization chamber 51 through the connecting pipe 19, and the data I / O terminal of the first ionization chamber is connected to the programmable logic controller 16 to collect the first current value I1.

[0032] The second measuring path 200 includes: the output end of the first ionization chamber 51 is connected to the input end of the first HTO separation device 61 through the connecting pipeline 19, the output end of the first HTO separation device 61 is connected to the input end of the second ionization chamber 52 through the connecting pipeline 19, the output end of the second ionization chamber 52 is connected to the first port of the first three-way electromagnetic valve 71 through the connecting pipeline 19, and the data I / O end of the second ionization chamber 52 is connected to the programmable logic controller 16 to collect the second current value I2.

[0033] The third measuring path 300 includes: the second port of the first three-way electromagnetic valve 71 is connected to the input end of the first dynamic balance valve 81 through the connecting pipeline 19, the output end of the first dynamic balance valve 81 is connected to the input end of the third ionization chamber 53 through the connecting pipeline 19, and the data I / O end of the third ionization chamber 53 is connected to the programmable logic controller 16 to collect the third current value I3.

[0034] The fourth measuring path includes: the third port of the first three-way electromagnetic valve 71 is connected to the input end of the second dynamic balance valve 82 through the connecting pipeline 19, the output end of the second dynamic balance valve 82 is connected to the input end of the HT catalytic device 11 through the connecting pipeline 19, the output end of the HT catalytic device 11 is connected to the input end of the second HTO separation device 62 through the connecting pipeline 19, the output end of the second HTO separation device 62 is connected to the input end of the fourth ionization chamber 54 through the connecting pipeline 19, and the data I / O end of the fourth ionization chamber 54 is connected to the programmable logic controller 16 to collect the fourth current value I4.

[0035] Further, the output end of the fourth ionization chamber 54 is connected to the first three-way electromagnetic valve 73 through the connecting pipeline 19, the second flow meter 92, the heating belt 13, and the input end of the dryer 12 in sequence, the output end of the dryer 12 is connected to the first port of the first three-way electromagnetic valve 73 through the connecting pipeline 19, the second port of the first three-way electromagnetic valve 73 is connected to the electronic vacuum gauge 2, and the vacuum pump 1 is connected at the same time, and the third port of the second port of the first three-way electromagnetic valve 73 is connected to the collection bottle 20.

[0036] Further, the output end of the third ionization chamber 53 is connected to the first flow meter 91, the bubbler 10 in sequence through the connecting pipeline 19, the output end of the bubbler 10 is connected to the first port of the second three-way electromagnetic valve 72 through the connecting pipeline 19, the second port of the second three-way electromagnetic valve 72 is connected to the electronic vacuum gauge 2 in sequence, and the vacuum pump 1 is connected, and the third port of the second port of the second three-way electromagnetic valve 72 is connected to the collection bottle 20.

[0037] Further, the control end of the vacuum pump 1, the electromagnetic valve 3, the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81, the second dynamic balance valve 82, the dryer 12, and the heating belt 13 is connected with the programmable logic controller 16, the data I / O end of the first ionization chamber 51, the second ionization chamber 52, the third ionization chamber 53, and the fourth ionization chamber 54 is connected with the programmable logic controller 16, and the programmable logic controller 16 is connected with the computer module 17 through a communication port.

[0038] Further, the temperature sensor 14 is connected with the heating belt 13, and the humidity sensor 15 is connected with the dryer 12.

[0039] Figure 2 The structure diagram of an embodiment of the dryer 12 of the application is shown in FIG. 6. The dryer 12 is a double-tube structure including a first Nafion dryer 121 and a second Nafion dryer 122. Sample gas enters the first Nafion dryer 121 from an input end 1211 and is output from an output port 1221 of the second Nafion dryer 122. An inlet of a purge gas path of the second Nafion dryer 122 is provided with a temperature flow controller 1222. In normal operation, the temperature and flow of the purge gas can be controlled to improve the drying efficiency of the dryer. After long-term operation of the equipment, the drying efficiency may

[0040] Figure 3 The HT catalytic device 11 of the application is composed of first, second, and third catalytic boxes 111, electric heating wires 112, and a shell including an input port 113 of the HT catalytic device and an output port 114 of the HT catalytic device. The first, second, and third catalytic boxes 111 are made of Al2O3 coated with 1% palladium material with high catalytic efficiency. The multi-stage HT catalytic oxidation based on density gradient is realized by the mass and distribution density of the palladium material in different catalytic devices. The density gradient of the first, second, and third catalytic boxes 111 increases in turn. The first, second, and third catalytic boxes 111 are mainly used for catalytic oxidation of HT to make it oxidized into HTO, thereby improving the catalytic efficiency.

[0041] The working principle and use process of the application are as follows: first, the test environment parameters and the control instruction conditions of the vacuum pump 1, the electromagnetic valve 3, the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81, the second dynamic balance valve 82, the dryer 12 and the heating belt 13 are set by the computer module 17, and are sent to the programmable logic controller 16; the electromagnetic valve 3 of the sample gas is controlled to be closed by the programmable logic controller 16, and the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81 and the second dynamic balance valve 82 are controlled to be in the open state and start, and the pipeline 19 environment is purified.

[0042] Then, the programmable logic controller 16 controls the vacuum pump 1 to start, and controls the vacuum pump 1 to stop when the vacuum parameter RH and the humidity parameter δ meet the vacuum condition δ1 and the humidity condition RH1, that is, δ≤δ1 and RH≤RH1, and records the humidity parameter δ1 and the vacuum parameter RH1; the programmable logic controller 16 controls the heating belt 13 to heat to t, and stops heating when t≥t1; the second three-way electromagnetic valve 72 and the third three-way electromagnetic valve 73 connected with the electronic vacuum gauge 2 and the vacuum pump 1 are controlled to be closed by the programmable logic controller 16; the electromagnetic valve 3 of the sample gas is controlled to be opened by the programmable logic controller 16, and the measured gas is input under the action of negative pressure; the electromagnetic valve 3, the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81 and the second dynamic balance valve 82 are controlled to be closed by the programmable logic controller 16 according to the time threshold value of the separation and discrimination measurement, and the current values I1, I2, I3 and I4 of the first ionization chamber 51, the second ionization chamber 52, the third ionization chamber 53 and the fourth ionization chamber 54 are recorded; the current values are collected by the programmable logic controller 16, and the data are sent to the computer module 17; and the computer module 17 calculates the activity concentration C of radon Rn, the activity concentration C of tritiated water HTO and the activity concentration C of tritium gas HT respectively.

[0043] The working principle and use process of the application are as follows: first, the test environment parameters and the control instruction conditions of the vacuum pump 1, the electromagnetic valve 3, the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81, the second dynamic balance valve 82, the dryer 12 and the heating belt 13 are set by the computer module 17, and are sent to the programmable logic controller 16; the electromagnetic valve 3 of the sample gas is controlled to be closed by the programmable logic controller 16, and the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81 and the second dynamic balance valve 82 are controlled to be in the open state and start, and the pipeline 19 environment is purified. Rn HTO HT The initial state of the equipment before measurement is restored by the programmable logic controller 16, and the next measurement is waited. Specific implementation 2

[0045] The application further discloses a radon-tritium separation and discrimination measurement method in a high-radon environment, which is applied to the radon-tritium separation and discrimination measurement equipment in a high-radon environment and includes the following steps.

[0046] ​​101: Set the condition threshold of the test environment parameters vacuum pump 1, electromagnetic valve 3, first three-way electromagnetic valve 71, second three-way electromagnetic valve 72, third three-way electromagnetic valve 73, first dynamic balance valve 81, second dynamic balance valve 82, dryer 12, heating belt 13 control instruction by computer module 16, and send to programmable logic controller 16, control the electromagnetic valve 3 connected to the sample gas output end to close by the programmable logic controller 16;

[0047] 102: Turn on, purify the pipeline 19 environment, control the electromagnetic valve 3 connected to the sample gas output end to close by the programmable logic controller 16, the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81, the second dynamic balance valve 82 are in the open state;

[0048] 103: Control the vacuum pump 1 to start by the programmable logic controller 16, and control the vacuum pump 1 to stop when the vacuum parameter RH and the humidity parameter δ meet the vacuum condition δ1 and the humidity condition RH1, that is, δ≤δ1 and RH≤RH1, record the humidity parameter δ1 and the vacuum parameter RH1;

[0049] 104: Control the heating belt 13 to heat to t by the programmable logic controller 16, and stop heating when t≥t1;

[0050] 105: Control the second three-way electromagnetic valve 72 and the third three-way electromagnetic valve 73 connected with the electronic vacuum gauge 2 and the vacuum pump 1 to close by the programmable logic controller 16;

[0051] 106: Control the electromagnetic valve 3 connected to the sample gas output end to open by the programmable logic controller 16, and input the gas to be measured;

[0052] 107: Close the first three-way electromagnetic valve 71, the second three-way electromagnetic valve 72, the third three-way electromagnetic valve 73, the first dynamic balance valve 81 and the second dynamic balance valve 82 according to the time threshold of the separation discrimination measurement by the programmable logic controller 16, record the current value I1 of the first ionization chamber 51, the current value I2 of the second ionization chamber 52, the current value I3 of the third ionization chamber 53 and the current value I4 of the fourth ionization chamber 54;

[0053] 108: According to the current values I1, I2, I3 and I4, respectively calculate the activity concentration C Rn of radon Rn, the activity concentration C HTO of tritiated water HTO and the activity concentration C HT of tritium gas HT, wherein:

[0054]

[0055] In the formula, I4 is the current value measured by the fourth ionization chamber 54, E αR is the radon gas in the mixed gas n Decay alpha particle energy, 5.3 MeV C Rn R is the radon gas in the mixed gas n Concentration, V is the sensitive volume of the ionization chamber, The average ionization energy required for an alpha particle to produce a pair of ion pairs is about 35.5 eV for a 5.3 MeV alpha particle

[0056]

[0057] In the formula, I3 is the current value measured by the third ionization chamber 53; E β The beta particle energy of tritium gas HT decay is 18.6 eV, and the average is 5.67 eV, C HT The tritium gas HT concentration in the mixed gas is

[0058]

[0059] In the formula, I1 is the current value measured by the first ionization chamber, I2 is the current value measured by the second ionization chamber 52, E β The beta particle energy of tritium gas HT decay is 18.6 eV, and the average is 5.67 eV, C HTO The tritiated water HTO concentration in the mixed gas is The average ionization energy required for a beta particle to produce a pair of ion pairs;

[0060] 109: Restoring the initial state of the pre-measurement device by the programmable logic controller 16.

[0061] The advantages of the present application are:

[0062] 1. The present application focuses on the characteristics of indoor environment, considers the influence of indoor radon gas on tritium measurement, and avoids the low detection limit challenge brought by multi-channel measurement through the series-parallel differential mode connection of the first measurement path 100, the second measurement path 200, the third measurement path 300 and the fourth measurement path 400, which is more suitable for low concentration level environment measurement, saves the demand for purging gas, and simplifies the device structure.

[0063] 2. The double-tube mode of the drying tube 12 further improves the separation performance and solves the problem of small adsorption capacity of single-tube, and compared with the semiconductor gradient cold trap, the Nafion dryer is cheap in price, high in cost performance and easy to maintain.

[0064] 3. The first ionization chamber 51, the second ionization chamber 52, the third ionization chamber 53 and the fourth ionization chamber 54 of the present application adopt a high-precision tritium ionization chamber with cancellation compensation, which reduces the influence of memory effect and environmental gamma on low-concentration tritium measurement, and further improves the measurement precision.

Claims

1. A radon-tritium separation discrimination measurement device in a high radon environment, comprising: The first, second, third and fourth measuring paths measure the first, second, third and fourth current values I1, I2, I3 and I4, respectively, and the activity concentrations C Rn of radon Rn, C HTO of tritiated water HTO and C HT of tritium gas HT are calculated from the first, second, third and fourth current values I1, I2, I3 and I4, respectively. wherein: The first measuring path includes: the input end of the electromagnetic valve and the output end of the sample gas are connected, the output end is connected with the input end of the filter through the connecting pipeline, the output end of the filter is connected with the input end of the first ionization chamber, the data I / O end of the first ionization chamber is connected with the programmable logic controller to collect the first current value I1; The second measuring path includes: the output end of the first ionization chamber of the first measuring path is connected with the first HTO separation device through the connecting pipeline, the output end of the first HTO separation device is connected with the input end of the second ionization chamber through the connecting pipeline, the data I / O end of the second ionization chamber is connected with the programmable logic controller to collect the second current value I2; The third measuring path includes: the output end of the second ionization chamber of the second measuring path is connected with the first port of the first three-way electromagnetic valve through the connecting pipeline; the second port of the first three-way electromagnetic valve is connected with the input end of the first dynamic balance valve through the connecting pipeline, the output end of the first dynamic balance valve is connected with the input end of the third ionization chamber, the output end of the third ionization chamber is connected with the first flow meter, the data I / O end of the third ionization chamber is connected with the programmable logic controller to collect the third current value I3; The fourth measuring path includes: the third port of the first three-way electromagnetic valve of the third measuring path is connected with the input end of the second dynamic balance valve through the connecting pipeline, the output end of the second dynamic balance valve is connected with the input end of the HT catalytic device through the connecting pipeline, the output end of the HT catalytic device is connected with the input end of the second HTO separation device through the connecting pipeline, the output end of the second HTO separation device is connected with the input end of the fourth ionization chamber through the connecting pipeline, the data I / O end of the fourth ionization chamber is connected with the programmable logic controller to collect the fourth current value I4; The output of the fourth ionization chamber is connected with the second flow meter, the heating belt and the dryer in sequence through the connecting pipeline, the output of the dryer is connected with the first port of the third three-way electromagnetic valve, the second port of the third three-way electromagnetic valve is connected with the electronic vacuum gauge and the vacuum pump, the third port of the third three-way electromagnetic valve is connected with the collection bottle; the output end of the first flow meter is connected with the input end of the bubbler, the output end of the bubbler is connected with the first port of the second three-way electromagnetic valve, the second port of the second three-way electromagnetic valve is connected with the electronic vacuum gauge and the vacuum pump, the third port of the second three-way electromagnetic valve is connected with the collection bottle.

2. The apparatus for radon and tritium separation and discrimination measurement in a high radon environment according to claim 1, characterized in that: The control ends of the vacuum pump, the electromagnetic valve, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve, the second dynamic balance valve, the dryer and the heating belt are connected with the programmable logic controller, the data I / O ends of the first ionization chamber, the second ionization chamber, the third ionization chamber and the fourth ionization chamber are connected with the programmable logic controller, and the programmable logic controller is connected with the computer module through the communication port.

3. The apparatus for measurement of discrimination of separation of radon and tritium in a high radon environment according to claim 1, characterized in that: Calculate the activity concentration C of radon Rn respectively. Rn The activity concentration C of HTO in tritium-treated water HTO Activity concentration C of tritium (HT) HT The formulas are as follows: Radon Rn activity concentration C Rn The formula is: (A1), where I4 is the current value measured in the fourth ionization chamber, and E α Radon gas R n The energy of the decaying alpha particle, C Rn Radon R in the mixed gas n Concentration, V is the sensitive volume of the fourth ionization chamber, The average ionization energy required to produce a pair of ions from an alpha particle; where the activity concentration C of tritium (HT) is... HT The formula is: In equation (A2), I3 is the current value measured in the third ionization chamber; E β C is the energy of the β particle from the decay of tritium (HT). HT The concentration of tritium (HT) in the mixed gas, the sensitive volume of the third ionization chamber (V3), and the activity concentration (C) of tritized water (HTO) are given. HTO for: In equation (A3), I1 is the current value measured in the first ionization chamber, I2 is the current value measured in the second ionization chamber, and E β C is the energy of the β particle from the decay of tritium (HT). HTO The concentration of water tritium (HTO) in the mixed gas. The average ionization energy required to produce a pair of ions for a β particle.

4. The apparatus for measurement of discrimination of separation of radon and tritium in a high radon environment according to claim 1, characterized in that: The dryer is a double-tube structure, comprising a first Nafion dryer and a second Nafion dryer, sample gas enters from the input end of the first Nafion dryer and is output from the output end of the second Nafion dryer, and the inlet of the purge gas path of the second Nafion dryer is provided with a temperature flow controller for controlling the temperature and flow of the purge gas.

5. The apparatus for measurement of discrimination of separation of radon and tritium in a high radon environment according to claim 1, characterized in that: The HT catalytic device is composed of two to six levels of gradient density catalytic boxes, and the HT catalytic device adopts Al2O3 coated with 1% palladium material as the catalytic material of the catalytic boxes of the HT catalytic device, and the mass and distribution density of the catalytic material of each level of catalytic box gradually increase from the inlet to the outlet.

6. The apparatus for measurement of discrimination of separation of radon and tritium in a high radon environment according to claim 1, characterized in that: The first ionization chamber, the second ionization chamber, the third ionization chamber and the fourth ionization chamber are cancellation compensation ionization chambers.

7. The apparatus of claim 1, wherein: The programmable logic controller is an UNC host or an industrial computer. ​ 8. The apparatus for measurement of discrimination of separation of radon and tritium in a high radon environment according to claim 1, characterized in that: The filter is a glass fiber filter membrane or a multi-layer filter membrane kit.

9. A method for radon-tritium separation discrimination measurement in a high-radon environment, applied to the device for radon-tritium separation discrimination measurement in a high-radon environment, comprising the following steps: 101: Set the test environment parameters and the control instructions of the vacuum pump, the electromagnetic valve, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve, the second dynamic balance valve, the dryer, and the heating belt through the computer module, and send them to the programmable logic controller; 102: Turn on, purify the pipeline environment, and control the electromagnetic valve of the sample gas to be closed, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve, and the second dynamic balance valve to be in the open state through the programmable logic controller; 103: Control the vacuum pump to be turned on through the programmable logic controller, and control the vacuum pump to be turned off when the vacuum parameter RH and the humidity parameter δ meet the vacuum condition δ1 and the humidity condition RH1, i.e., δ≤δ1 and RH≤RH1, and record the humidity parameter δ1 and the vacuum parameter RH1; 104: Control the heating belt to be heated to t through the programmable logic controller, and stop heating when t≥t1; 105: Control the second three-way electromagnetic valve and the third three-way electromagnetic valve connected with the electronic vacuum gauge and the vacuum pump to be closed through the programmable logic controller; 106: Control the electromagnetic valve of the sample gas to be opened through the programmable logic controller, and input the gas to be measured; 107: Close the electromagnetic valve, the first three-way electromagnetic valve, the second three-way electromagnetic valve, the third three-way electromagnetic valve, the first dynamic balance valve, and the second dynamic balance valve according to the time threshold value of the separation discrimination measurement through the programmable logic controller, record the first current value I1 of the first ionization chamber, the second current value I2 of the second ionization chamber, the third current value I3 of the third ionization chamber, and the fourth current value I4 of the fourth ionization chamber; 108: Calculate the activity concentration C of radon Rn, respectively, according to the first current value I1, the second current value I2, the third current value I3 and the fourth current value I4 Rn , the activity concentration C of tritiated water HTO HTO , the activity concentration C of tritium gas HT HT , the activity concentration C of radon Rn Rn The formula is: In formula (A1), I4 is the current value measured by the fourth ionization chamber, E α is the α particle energy of radon R n Decay, C Rn is the concentration of radon R n In the mixed gas, V is the sensitive volume of the fourth ionization chamber, Is the average ionization energy required for an α particle to produce a pair of ion pairs; wherein the activity concentration C HT Of tritium gas HT is: In formula (A2), I3 is the current value measured by the third ionization chamber; E β is the β particle energy of tritium gas HT decay, C HT is the concentration of tritium gas HT in the mixed gas; the activity concentration C HTO Of tritiated water HTO is: In formula (A3), I1 is the current value measured by the first ionization chamber, I2 is the current value measured by the second ionization chamber, E β is the β particle energy of tritium gas HT decay, C HTO is the concentration of tritiated water HTO in the mixed gas, Is the average ionization energy required for a β particle to produce a pair of ion pairs; 109: Reset.

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