System and method for detecting leakage rate of seal box to environment
阅读说明：本技术 一种密封箱向环境泄漏率检测系统和方法 (System and method for detecting leakage rate of seal box to environment ) 是由 刘鲜丽 王坤俊 丘丹圭 侯建荣 张渊 李永国 张崇文 王稹 常森 邱继林 张志凯 于 2021-07-14 设计创作，主要内容包括：本发明涉及一种密封箱向环境泄漏率检测系统和方法,系统包括外箱、示踪剂注入装置、第一采样装置、第二采样装置和γ谱仪,外箱用于包容试验箱,示踪剂注入装置置于所述试验箱内,第一采样装置通过管道连通所述试验箱,第二采样装置通过管道连通所述外箱,γ谱仪用于测定所述第一采样装置和所述第二采样装置采集到样本的活度；本发明系统和方法通过采集一段时间内试验箱和外箱内气体的变化,测定第一采样装置和第二采样装置采集到样本的活度,可以检测出不同工作条件下,高密封等级箱体内示踪剂气体向环境极微量泄漏值,方法灵敏度高,受温度、湿度等条件的影响小。(The invention relates to a system and a method for detecting the leakage rate of a seal box to the environment, wherein the system comprises an outer box, a tracer injection device, a first sampling device, a second sampling device and a gamma spectrometer, the outer box is used for containing a test box, the tracer injection device is arranged in the test box, the first sampling device is communicated with the test box through a pipeline, the second sampling device is communicated with the outer box through a pipeline, and the gamma spectrometer is used for measuring the activity of a sample collected by the first sampling device and the second sampling device; the system and the method can detect the trace leakage value of tracer gas in the box body with high sealing grade to the environment under different working conditions by acquiring the change of the gas in the test box and the outer box within a period of time and measuring the activity of the samples acquired by the first sampling device and the second sampling device, and the method has high sensitivity and is less influenced by conditions such as temperature, humidity and the like.)
1. A seal box leaks rate detecting system to environment which characterized in that includes:
the outer box is used for containing the test box;
a tracer injection device, which is arranged in the test chamber and is used for injecting a tracer into the test chamber;
the first sampling device is communicated with the test box through a pipeline and is used for collecting a gas sample in the test box;
the second sampling device is communicated with the outer box through a pipeline and is used for collecting a gas sample in the outer box;
and the gamma spectrometer is used for measuring the activity of the samples collected by the first sampling device and the second sampling device.
2. The system of claim 1, further comprising a first air flow perturbation device disposed within the test chamber for perturbing the air flow within the test chamber.
3. The system of claim 2, further comprising a second air flow disruption means disposed within the outer box for disrupting the air flow within the outer box.
4. The system of claim 1, further comprising a first purging device in fluid communication with the test chamber via a conduit and a second purging device in fluid communication with the outer box via a conduit for removing the tracer gas.
5. A method for detecting the leakage rate of a seal box to the environment, which is characterized by being carried out by using the system for detecting the leakage rate of the seal box to the environment as claimed in any one of claims 1 to 4, and comprising the following steps:
(1) adjusting the pressure of the test chamber to meet the detection requirement;
(2) injecting a tracer gas into the test chamber;
(3) starting a second sampling device, and collecting gas in the outer box for a period of time;
(4) starting a first sampling device, and collecting gas in the test chamber for a period of time;
(5) and measuring the activity values of the samples collected by the first sampling device and the second sampling device through a gamma spectrometer, and calculating the tracer leakage rate value of the test chamber to the environment.
6. The method of claim 5, wherein the step of detecting the leakage rate of the seal box to the environment comprises the steps of: in the step (2), the tracer gas is a short-lived radionuclide labeled gas.
7. The method of claim 6, wherein the step of detecting the leakage rate of the seal box to the environment comprises the steps of: in the step (2), the injection activity concentration value of the tracer gas is more than 8.2 multiplied by 103Bq/m3。
8. The method of claim 5, wherein the step of detecting the leakage rate of the seal box to the environment comprises the steps of: in the step (4), the starting time for collecting the gas in the outer box is the same as the injection time of the tracer in the test box.
9. The method of claim 5, wherein the step of detecting the leakage rate of the seal box to the environment comprises the steps of: in the step (5), a calculation formula for calculating the tracer leakage rate value of the test chamber to the environment is as follows:
in the formula, v1Is the total volume (m) of the outer box3)；v2Sampling the Total volume (m) for the outer Box3)；a1Is the outer case sample measurement (Bq); v1Sample the total volume (m) for the test chamber3)；V2Is the total volume (m) of the test chamber3)；A1The inner box sample measurement (Bq).
Technical Field
The invention belongs to the field of nuclear technology application, and particularly relates to a system and a method for detecting the leakage rate of a seal box to the environment.
Background
The uranium plutonium Mixed Oxide (MOX) fuel is a closed cycle fuel assembly which is applied more at present, accords with strategic development requirements of nuclear fission sustainable development, and has good market prospect. Plutonium is highly toxic and can be easily inhaled by a human body, and once the plutonium permeates into the environment, the plutonium can cause harm to workers and the environment. Therefore, in the MOX fuel assembly development test operating line, plutonium-related operations were all performed in a sealed, shielded glove box. The general glove box is designed to work under the pressure of (-300 to-400) Pa so as to reduce the seepage of the gas in the box to the environment.
Under the working condition, the leakage rate of harmful gas in the box to the environment is a direct determining factor influencing the safety of workers and the environment, so that the leakage rate of the harmful gas in the negative pressure sealing box to the environment is very necessary to determine and is an important reference for designing and establishing the working condition of the glove box. The detection technology of the leakage rate of the gas in the high-sealing-level box body to the environment is not reported in the published literature data at home and abroad at present.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a system and a method for detecting the leakage rate of a sealed box to the environment, which are applied to the detection of the leakage rate of the sealed box to the environment with a high sealing grade.
In order to achieve the above purposes, the invention adopts the technical scheme that: a seal box to environment leakage rate detection system, comprising:
the outer box is used for containing the test box;
a tracer injection device, which is arranged in the test chamber and is used for injecting a tracer into the test chamber;
the first sampling device is communicated with the test box through a pipeline and is used for collecting a gas sample in the test box;
the second sampling device is communicated with the outer box through a pipeline and is used for collecting a gas sample in the outer box;
and the gamma spectrometer is used for measuring the activity of the samples collected by the first sampling device and the second sampling device.
Furthermore, the system for detecting the leakage rate of the seal box to the environment further comprises a first air flow disturbance device, wherein the first air flow disturbance device is arranged in the test box and used for disturbing the air flow in the test box.
Furthermore, the seal box is still including second air current disturbance device to environmental leakage rate detecting system, place in the second air current disturbance device the outer container for the disturbance air current in the outer container.
Further, the seal box is still including first purifier and second purifier to environmental leakage rate detecting system, first purifier passes through the pipeline intercommunication the proof box, second purifier passes through the pipeline intercommunication the outer container for get rid of the tracer gas.
A method for detecting the leakage rate of a seal box to the environment is carried out by using the system for detecting the leakage rate of the seal box to the environment, and comprises the following steps:
(1) adjusting the pressure of the test chamber to meet the detection requirement;
(2) injecting a tracer gas into the test chamber;
(3) starting the second sampling device, and collecting the gas in the outer box for a period of time;
(4) starting the first sampling device, and collecting the gas in the test chamber for a period of time;
(5) and measuring the activity values of the samples collected by the first sampling device and the second sampling device through the gamma spectrometer, and calculating the tracer leakage rate value of the test chamber to the environment.
Further, in the step (2), the tracer gas is a short-lived radionuclide labeled gas.
Further, in the step (2), the injection activity concentration value of the tracer gas is more than 8.2 x 103Bq/m3。
Further, in the step (4), the starting time of collecting the gas in the outer box is the same as the injection time of the tracer in the test box.
Further, in the step (5), the calculation formula for calculating the tracer leakage rate value of the test chamber to the environment is as follows:
in the formula, v1Is the total volume (m) of the outer box3)；v2Sampling the Total volume (m) for the outer Box3)；a1Is the outer case sample measurement (Bq); v1Sample the total volume (m) for the test chamber3)；V2Is the total volume (m) of the test chamber3)；A1The inner box sample measurement (Bq).
The invention has the following effects: by adopting the system and the method, the activity of the samples collected by the first sampling device and the second sampling device is measured by collecting the change of the gas in the test chamber and the outer box within a period of time, and the leakage rate of the test chamber can be measured according to the trace leakage rate of the tracer gas to the environment.
Drawings
FIG. 1 is a block diagram of the system of the present invention;
FIG. 2 is a flow chart of the method of the present invention.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
As shown in fig. 1, a system for detecting the leakage rate of a sealed box to the environment comprises an outer box 1, a tracer injection device 2, a first sampling device 3, a second sampling device 4 and a gamma spectrometer 5. Wherein outer container 1 is used for holding proof box 6 to form the space that can the simulated environment between outer container 1 and proof box 6, conveniently sample ambient gas in the space.
The tracer injection device 2 of the present embodiment is built in the test chamber 6, and is used to inject the tracer into the test chamber 6. When the tracer leaks from test chamber 6 to outer case 1, the leak rate of test chamber 6 can be determined based on the amount of leakage of the tracer.
The first sampling device 3 of the embodiment is communicated with the test chamber 6 through a pipeline and is used for collecting a gas sample in the test chamber 6; the second sampling device 4 is communicated with the outer box 1 through a pipeline and is used for collecting the gas sample in the outer box 1. It is noted that the number of sampling devices can be set according to actual needs.
The gamma spectrometer 5 is used for measuring the activity of the samples collected by the first sampling device 3 and the second sampling device 4. In the present embodiment, the gamma spectrometer 5 uses a MAESTRO-32 gamma spectrometer 5. Of course, other types of gamma spectrometers 5 can be used according to actual needs.
Further, the system for detecting the leakage rate of the seal box to the environment of the embodiment further comprises a first air flow disturbance device 7 and a second air flow disturbance device 8, wherein the first air flow disturbance device 7 is arranged in the test box 6 and is used for disturbing the air flow in the test box 6. The second airflow disturbing device 8 is arranged in the outer box 1 and is used for disturbing the airflow in the outer box 1. Through the disturbance of the first airflow disturbance device 7 and the second airflow disturbance device 8 to the airflow, the radioactive tracer can be dispersed in the box body more uniformly, so that the collected gas sample is more uniform, and the data is more accurate. It is noted that the number of the air flow disturbing devices can be set according to actual needs. For example, in the present embodiment, two first air flow disturbance devices 7 are provided, and the two first air flow disturbance devices 7 are respectively arranged at two diagonal corners inside the test chamber 6.
Further, the seal box leakage rate detection system to the environment further comprises a first purification device 9 and a second purification device 10, wherein the first purification device 9 is communicated with the test box 6 through a pipeline, and the second purification device 10 is communicated with the outer box 1 through a pipeline and used for removing radioactive gas. It should be noted that the second purifying device 10 can be installed according to actual conditions, and can also be combined with the outer box sampling device 4.
An exemplary method for seal box leak rate detection using the above exemplary seal box to environment leak rate detection system of the present invention and results are as follows:
a method for detecting the leakage rate of a seal box to the environment is carried out by using the system for detecting the leakage rate of the seal box to the environment, and comprises the following steps:
(1) adjusting the pressure of the test box 6 to meet the detection requirement; wherein, the atmospheric pressure change of the test box 6 is less than 1000 Pa; the relative pressure change in the test chamber 6 is less than 100 Pa; the internal temperature variation is less than 3 ℃.
(2) Injecting tracer gas into the test chamber 6; in this embodiment, the tracer gas is a short-lived radionuclide labeled gas, such as radioactive methyl iodide gas, and the concentration value of the injection activity of the tracer gas is greater than 8.2 × 103Bq/m3。
(3) Starting a second sampling device 4, and collecting gas in the outer box 1 for a period of time; in this example, the collection time was 1 hour.
(4) Starting the first sampling device 3, and collecting the gas in the test chamber 6 for a period of time; the gas collection of the test box 6 needs to be started after the outer box 1 finishes sampling, and the collection time is 8 minutes. Capturing tracer gas in a sample gas flow by a sampler; in this example, the tracer gas is radioactive methyl iodide gas, the sampler is provided with an iodine sampling carbon box inside, and the MAESTRO-32 gamma spectrometer 5 is used to measure the gamma count.
(5) The activity values of the samples collected by the first sampling device 3 and the second sampling device 4 are measured by the gamma spectrometer 5, and the tracer leakage rate value of the test chamber 6 to the environment is calculated.
Further, in the step (5), the calculation formula for calculating the tracer leakage rate value of the test chamber 6 to the environment is as follows:
in the formula, v1The total volume (m) of the outer box 13)；v2Sample the total volume (m) for the outer case 13)；a1Measured for the case 1 sample (Bq); v1Sample the total volume (m) for test chamber 63)；V2Is the total volume (m) of the test chamber 63)；A1The inner box sample measurement (Bq).
The tests are repeated under different working pressures of the environment by using test boxes with different sealing grades, and the measured results of the leakage rate of the tracer agent to the environment per hour are shown in the following table 1.
TABLE 1 detection result of tracer leakage rate per hour from sealed box to environment
As shown in the table, the sealing boxes with the sealing grades of 1 grade and 2 grade respectively quantitatively detect the tracer leakage of the box body to the environment per hour under the working pressure of (-300 +/-100) Pa, and the value is obviously increased when the pressure is close to 0 Pa. The results show that: the method and the system for detecting the leakage rate of the seal box can quantitatively detect the leakage rate of the tracer to the environment per hour under the negative pressure working condition.
It will be appreciated by those skilled in the art that the method and system of the present invention are not limited to the embodiments illustrated in the detailed description, which is intended to be illustrative of the invention and is not intended to be limiting. Other embodiments will be apparent to those skilled in the art from the following detailed description, which is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
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