Gas sampling and quantification module, reactor building atmosphere sampling system and method

Abstract

The application discloses a gas sampling and quantifying module, a sampling system and method for a reactor plant atmosphere. The gas sampling and quantifying module comprises at least one quantifying ring for quantitatively sampling sample gas, a multi-way valve comprising a gas inlet end and a gas outlet end and at least one set of quantifying ring connection end groups, the quantifying ring connection end groups comprising a quantifying ring first connection end and a quantifying ring second connection end, a dilution unit connection end and a sampling unit connection end. When in a sampling mode, the gas inlet end, the quantifying ring first connection end, the quantifying ring, the quantifying ring second connection end and the gas outlet end are sequentially connected. When in a quantifying mode, the dilution unit connection end, the quantifying ring first connection end, the quantifying ring, the quantifying ring second connection end and the sampling unit connection end are sequentially connected in series. The scheme realizes quantitative sampling of airborne radioactive substances in the atmosphere in a reactor plant.

Description

Technical Field

[0001] This invention relates to the field of atmospheric sampling technology for nuclear power plants in the event of an accident and after an accident, and particularly to a gas sampling and quantification module, a sampling system and method for the atmosphere of the reactor building. Background Technology

[0002] In the event of a design basis accident (such as a large breach loss-of-coolant accident) or a severe accident (core damage), a nuclear power plant may release large amounts of radioactive material into the reactor building in both gaseous and liquid forms. Gaseous radioactive material diffuses into the reactor building atmosphere, while liquid radioactive material flows into a sump and is collected. To accurately assess the severity of a nuclear accident within the reactor building, measurements from on-site temperature, humidity, pressure, and radiation monitoring instruments can be used. Alternatively, samples can be taken from the reactor building atmosphere and sump waste liquid and analyzed in a laboratory to determine the concentration of radionuclides. The sampling and analysis results of radioactive waste liquid from the reactor building are crucial decision-making information for the nuclear power plant's emergency command center regarding the orderly and controlled release of radioactive waste liquid into the environment.

[0003] In the current technology, the atmospheric sampling system of the reactor building uses a sampling pump to extract samples. The flow rate of the sampling pump is generally 10L / min to 30L / min, which cannot achieve quantitative sampling of 1mL or 0.1mL of atmospheric samples from the reactor building. The samples need to be processed before they can be analyzed by the gamma spectrometer in the laboratory. During the sample processing, the radioactivity of the sample decreases, resulting in inaccurate radioactivity of the sample obtained in the final analysis. Summary of the Invention

[0004] The embodiments of the present invention provide a gas sampling and quantification module, a sampling system and method for the atmosphere of a reactor building, which aims to solve the problem of inaccurate sample analysis results caused by the inability to quantitatively sample airborne radioactive materials in the atmosphere of a reactor building after a design basis accident or a serious accident in a nuclear power plant.

[0005] In a first aspect, the gas injection and quantification module includes: at least one quantitative loop for quantitative sampling of sample gas; a multi-port valve including an inlet end and an outlet end, and at least one set of quantitative loop connection end groups, wherein the quantitative loop connection end group includes a first quantitative loop connection end and a second quantitative loop connection end, a dilution unit connection end and a sampling unit connection end; wherein, in the injection mode, the inlet end, the first quantitative loop connection end, the quantitative loop, the second quantitative loop connection end and the outlet end are connected in sequence; and / or, in the quantification mode, the dilution unit connection end, the first quantitative loop connection end, the quantitative loop, the second quantitative loop connection end and the sampling unit connection end are connected in series.

[0006] Secondly, embodiments of the present invention also provide a sampling system for reactor building atmosphere, comprising: a gas sampling and quantification unit, including the gas sampling and quantification module as described above; an inlet unit connected to the inlet end, the inlet unit being used to allow reactor building atmosphere to pass through the containment and enter the sampling system; an exhaust unit connected to the outlet end, the exhaust unit being used to allow gas in the sampling system to pass through the containment and be discharged into the reactor building; a sampling unit connected to the sampling unit connection end and the exhaust unit, the sampling unit being used to contain the sampled reactor building atmosphere gas; and a diluent injection unit connected to the diluent unit connection end and the exhaust unit, the diluent injection unit being used to inject diluent into the gas sampling and quantification unit so that the sampling unit obtains diluted sample gas.

[0007] Thirdly, embodiments of the present invention also provide a method for sampling the atmosphere of a reactor building, applied to the reactor building atmosphere sampling system described above, comprising: controlling the multi-way valve to be in the sampling mode; opening the inlet unit and the exhaust unit to allow the metering loop to quantitatively inject the sample gas; closing the inlet unit and controlling the multi-way valve to be in the metering mode; opening the diluent injection unit to blow the sample gas in the metering loop into the sampling unit to dilute and sample the sample gas; closing the diluent injection unit and the exhaust unit to obtain a gas sample from the sampling unit.

[0008] Compared with the prior art, the beneficial effects of the present invention are:

[0009] In the technical solution of this invention, radioactive gas is quantitatively injected in injection mode by using a multi-port valve in conjunction with a quantitative loop. The function is then switched by the multi-port valve, so that in quantitative mode, the dilution unit is connected to the dilution unit and the sampling unit is connected to the sampling unit through the dilution unit connection end. This transfers the quantitatively injected radioactive gas in the quantitative loop to the sampling unit, realizing the quantitative sampling of airborne radioactive materials in the atmosphere of the reactor building after a design basis accident or severe accident in a nuclear power plant. This allows for more accurate analytical results to be obtained from the final sample analysis. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A schematic diagram of the gas injection and quantification module provided by the present invention;

[0012] Figure 2 A schematic diagram of the quantitative mode of the gas injection and quantitative module provided by the present invention;

[0013] Figure 3 A schematic diagram of the atmospheric sampling system for a reactor building provided by the present invention;

[0014] Figure 4 A schematic diagram of the control relationship of the gas sampling system control module for the atmosphere of the reactor building provided by the present invention;

[0015] Figure 5 A schematic diagram illustrating the steps of the reactor building atmosphere sampling method provided by the present invention;

[0016] Figure 6 A schematic diagram of the sub-steps of the method for sampling the atmosphere of a reactor building provided by the present invention;

[0017] Figure 7 A schematic diagram of another sub-step of the method for sampling the atmosphere of a reactor building provided by the present invention;

[0018] Explanation of reference numerals in the attached figures:

[0019] 01. Pressure sensor #1; 02. Temperature sensor #2; 03. Pressure sensor #3; 04. Gamma dose rate detector; 05. Temperature sensor #5; 06. Pressure sensor #6; 09. Electric valve #9; 010. Electric valve #10; 011. Flow meter #11;

[0020] 10. Intake module; 101. Electric valve No. 101; 102. Electric valve No. 102; 103. Electric valve No. 103; 104. Electric valve No. 104;

[0021] 20. Flow control module; 201. Electric valve No. 201; 202. Electric valve No. 202; 203. Electric valve No. 203; 204. Pump;

[0022] 30. Gas injection and quantification unit; 31. Gas injection and quantification module; 301. Multi-port valve; 30101. Gas inlet; 30102. First connection end of the first quantification loop; 30103. Connection end of the first sampling unit; 30104. Connection end of the first dilution unit; 30105. Second connection end of the second quantification loop; 30106. Gas outlet; 30107. Second connection end of the first quantification loop; 30108. First connection end of the second quantification loop; 30109. Connection end of the second dilution unit; 30110. Connection end of the second sampling unit;

[0023] 302. First metering loop; 303. Second metering loop; 304. Electric valve No. 304; 305. Electric valve No. 305; 306. Electric valve No. 306; 307. Electric valve No. 307; 308. Flow meter No. 308; 309. Flow meter No. 309;

[0024] 40. Sampling unit; 41. First quantitative loop sampling module; 42. Second quantitative loop sampling module; 401. First quick connector; 402. First aerosol and iodine retention bottle; 403. First switching valve; 404. First gas dilution bottle; 405. Electric valve No. 405; 406. Electric valve No. 406; 407. Second gas dilution bottle; 408. Electric valve No. 408; 409. Electric valve No. 409; 410. Second Quick connector; 411, First gas sampling bottle; 412, Second aerosol and iodine retention bottle; 413, Third switching valve; 414, Third gas dilution bottle; 415, Electric valve No. 415; 416, Electric valve No. 416; 417, Fourth gas dilution bottle; 418, Electric valve No. 418; 419, Electric valve No. 419; 420, Fourth quick connector; 421, Second gas sampling bottle; 422, Third quick connector;

[0025] 50. Injection module; 501. Gas injector; 502. Electric valve No. 502; 503. Nitrogen cylinder;

[0026] 60. Exhaust module; 601. Electric valve No. 601; 602. Electric valve No. 602; 603. Electric valve No. 603; 604. Electric valve No. 604;

[0027] 70. Diluent injection unit; 701. Inert gas source; 702. Second switching valve;

[0028] 90. Gas sampling system control module. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0033] To address the problem of inaccurate sample analysis results caused by the inability to quantitatively sample airborne radioactive materials in the atmosphere of the reactor building after a design basis accident or severe accident in a nuclear power plant, this invention proposes a gas sampling and quantification module 31, which includes: at least one quantitative loop for quantitative sampling of sample gas; a multi-way valve 301, which includes an inlet end 30101 and an outlet end 30106, and at least one set of quantitative loop connection end groups, the quantitative loop connection end group including a first quantitative loop connection end and a second quantitative loop connection end, a dilution unit 70 connection end, and a sampling unit 40 connection end; wherein, in the sampling mode, the inlet end 30101, the first quantitative loop connection end, the quantitative loop, the second quantitative loop connection end, and the outlet end 30106 are connected in sequence; and / or, in the quantification mode, the dilution unit connection end, the first quantitative loop connection end, the quantitative loop, the second quantitative loop connection end, and the sampling unit 40 connection end are connected in series.

[0034] Reference Figure 1 , Figure 2 and Figure 3As shown, the so-called quantitative loop is used to accurately measure and control the gas volume, ensuring the consistency of sample volume in each sampling. The so-called multi-way valve 301 is used to connect different connection ends to realize the connection between various functional pipelines, and to change the interconnection relationship between different connection ends by switching the valve port. In this embodiment, a rotary multi-way valve 301 is specifically used. In the rotary multi-way valve 301, the valve core is cylindrical or spherical. As the valve stem rotates, different surfaces of the valve core align with the channels in the valve body, thereby realizing the switching. In order to first perform quantitative sampling of the highly radioactive atmosphere in the reactor building after the accident, it is necessary to first quantitatively inject the radioactive atmosphere through the quantitative loop, and then transfer the radioactive sample gas in the quantitative loop for sampling. Therefore, to achieve the above-mentioned quantitative injection and sampling, at least one multi-way valve 301 with six external ends is required to realize the function. The multi-way valve 301 is provided with an inlet end 30101 and an outlet end 30106 to provide channels for gas injection and discharge. It also includes a quantitative loop connection assembly, which comprises a first connection end and a second connection end of the quantitative loop, serving as channels for the radioactive gas to enter and exit the quantitative loop, respectively. It is important to emphasize that, if... Figure 3Taking this example for understanding, in this embodiment, the so-called first end of the quantitative loop can be considered as the first connection end 30102 of the first quantitative loop, the so-called second connection end of the quantitative loop can be considered as the second connection end 30105 of the second quantitative loop, and the so-called quantitative loop can be considered as a collection of the first quantitative loop 302, the first connection end 30107 of the first quantitative loop, the first connection end 30108 of the second quantitative loop, and the second quantitative loop 303. The so-called quantitative loop connection end group also includes a dilution unit connection end and a sampling unit 40 connection end. The dilution unit connection end is used to connect to the dilution unit and to adjust the concentration of the sample gas obtained by the final sampling. The sampling unit 40 connection end is used to connect to the sampling unit 40 and to inject the quantitative radioactive gas sample transferred from the quantitative loop into the sampling unit 40 to achieve quantitative sampling of the reactor building atmosphere. In this embodiment, the use of the quantitative loop to sample the radioactive atmosphere and the sampling of the radioactive atmosphere sample that has been quantitatively sampled from the quantitative loop are respectively referred to as the sampling mode and the quantitative mode. In these two modes, the multi-port valve 301 is in two different valve port switching states. When in sample introduction mode, the radioactive gas flow path is: inlet 30101, first connection of the quantitative loop, quantitative loop, second connection of the quantitative loop, and outlet 30106. This path ensures that the gas remains undisturbed after entering the quantitative loop, accurately maintaining the sample's state. When in quantitative mode, the diluent gas flowing from the dilution unit to transfer and dilute the radioactive gas in the quantitative loop flows through: dilution unit connection, first connection of the quantitative loop, quantitative loop, second connection of the quantitative loop, and sampling unit 40 connection. This path allows for necessary dilution before sample acquisition to meet the concentration requirements for subsequent analysis. The reason for dilution is that the acceptable upper limit of radioactivity of the analyte analyzed by the gamma spectrometer in the nuclear power plant laboratory is 10⁻⁶. 6 If Bq is sampled directly without dilution, the radioactivity of the sample gas will be far higher than the upper limit, making it impossible for the gamma spectrometer to measure normally, and secondary dilution is required.

[0035] Compared to existing technologies, the gas sampling and quantification module 31 of this invention uses a multi-way valve 301 in conjunction with a quantitative loop to quantitatively sample radioactive gases in the reactor building in sampling mode. The multi-way valve 301 then switches functions so that in quantitative mode, the dilution unit is connected via the dilution unit connection end, and the sampling unit 40 connection end is connected to the sampling unit 40. This transfers the quantitatively sampled radioactive gas from the quantitative loop to the sampling unit 40, enabling quantitative sampling of airborne radioactive materials in the atmosphere of the reactor building after a design basis accident or severe accident at a nuclear power plant. This results in more accurate analytical results for the final sample.

[0036] In one embodiment, reference is made to Figure 1 , Figure 2 and Figure 3 As shown, the gas injection and quantification module 31 of the present invention includes a first quantification ring 302, a second quantification ring 303, and correspondingly arranged first and second quantification ring connection end groups; wherein, in the injection mode, the gas inlet 30101, the first quantification ring first connection end 30102, the first quantification ring 302, the first quantification ring second connection end 30107, the second quantification ring first connection end 30108, the second quantification ring 303, and the second quantification ring second connection end are connected. Terminal 30105 and outlet 30106 are connected in sequence. In quantitative mode, the first dilution unit connection terminal 30104, the second connection terminal of the first quantitative loop 30107, the first quantitative loop 302, the first connection terminal of the first quantitative loop 30102, and the first sampling unit connection terminal 30103 are connected in sequence. The second dilution unit connection terminal 30109, the first connection terminal of the second quantitative loop 30108, the second quantitative loop 303, the second connection terminal of the second quantitative loop 30105, and the second sampling unit connection terminal 30110 are connected in sequence. To achieve more flexible quantitative sampling and improve measurement accuracy, two quantitative loops of different volumes need to be set, namely the first quantitative loop 302 and the second quantitative loop 303. The volume of the first quantitative loop 302 is 1 ml, and the volume of the second quantitative loop 303 is 0.1 ml. By using quantitative loops of different capacities, dilutions can be performed at different sampling stages or when connecting different dilution units, ensuring that the final diluted sample reaches the required analytical concentration. This makes the concentration adjustment of gas samples more precise and convenient. Since two quantitative loops are used, a set of quantitative loop connection terminals also needs to be added to the multi-port valve 301. In this case, the multi-port valve 301 should include six external terminals to achieve the desired function. In practical applications, even smaller quantitative loops can be selected to work with the multi-port valve 301 for quantitative sampling of smaller volumes of atmospheric samples from reactor buildings.

[0037] Furthermore, in order to realize the function of the multi-way valve 301, in addition to the inlet end 30101 and the outlet end 30106, the multi-way valve 301 also includes a first set of metering ring connection end groups and a second set of metering ring connection end groups. The first metering ring 302 connection end group includes a first metering ring first connection end 30102, a first metering ring second connection end 30107, a first dilution unit connection end 30104, and a first sampling unit connection end 30103. The second metering ring 303 connection end group includes a second metering ring first connection end 30108, a second metering ring second connection end 30105, a second dilution unit connection end 30109, and a second sampling unit connection end 30110. When in the injection state, the gas flow path is as follows: inlet 30101, first connection end of first quantitative loop 30102, first quantitative loop 302, second connection end of first quantitative loop 30107, first connection end of second quantitative loop 30108, second quantitative loop 303, second connection end of second quantitative loop 30105, outlet 30106. The radioactive gas passes through two quantitative loops at once through the above path, and the two quantitative loops complete the quantitative injection at the same time. This saves on quantitative injection and also prevents the 1 ml quantitative loop from taking too much sample through the 0.1 ml quantitative loop, avoiding sample saturation and affecting subsequent analysis. In quantitative mode, the flow path of the diluent gas flowing out of the dilution unit to transfer and dilute the radioactive gas in the quantitative loop is divided into two paths. The first path is: first dilution unit connection end 30104, first quantitative loop second connection end 30107, first quantitative loop 302, first quantitative loop first connection end 30102, first sampling unit connection end 30103. The second path is: second dilution unit connection end 30109, second quantitative loop first connection end 30108, second quantitative loop 303, second quantitative loop second connection end 30105, second sampling unit connection end 30110. The diluent gas transfers the radioactive gas in the quantitative loop to the sampling unit 40 to complete the sampling. During this process, the sampling processes of the first quantitative loop 302 and the second quantitative loop 303 do not interfere with each other, allowing independent dilution and sampling operations for each quantitative loop, resulting in more accurate sampling results. The resulting diluted samples have two different orders of magnitude. When measuring the samples, these two orders of magnitude help to minimize the risk of the sampled samples exceeding the upper limit of radioactivity acceptable to the gamma spectrometer. The gas sampling and quantification module 31 in this embodiment features a more flexible connection system, enabling rapid switching between sampling and quantification modes based on the actual needs of atmospheric sampling in the reactor building after an accident. Furthermore, the design of two quantification loops with different capacities allows for more precise gas sampling and analysis. Moreover, this gas sampling and quantification module 31 is applicable to various gas analysis scenarios, including environmental monitoring and industrial gas detection.

[0038] Specifically, refer to Figure 1 , Figure 2 and Figure 3 As shown, the gas sampling and quantification module 31 of this invention is further equipped with an electric valve 306 connected to the first sampling unit connection terminal 30103, an electric valve 307 connected to the second sampling unit connection terminal 30110, an electric valve 304 connected to the first dilution unit connection terminal 30104, and an electric valve 305 connected to the second dilution unit connection terminal 30109. These electric valves are used to control the flow of gas and, under certain circumstances, isolate the gas sampling and quantification module 31 from external interconnection, thereby ensuring the safety of the gas sampling and quantification module 31. Flow meters 308 and 309 are also provided to monitor the flow rate of the diluent gas and prevent excessive injection of diluent gas.

[0039] This invention also provides a reactor building atmosphere sampling system, specifically for post-accident reactor building atmosphere sampling, referring to... Figure 3The reactor building atmosphere sampling system includes a gas sampling and quantification unit 30, comprising the gas sampling and quantification module 31 as described in the previous embodiment; an intake unit connected to an intake end 30101, used to allow the reactor building atmosphere to pass through the containment structure and enter the sampling system; an exhaust unit connected to an exhaust end 30106, used to allow the gas in the sampling system to pass through the containment structure and be discharged into the reactor building; a sampling unit 40 connected to the sampling unit 40 connection end and the exhaust unit, used to contain the sample gas to be sampled; and a diluent injection unit 70 connected to the dilution unit connection end and the exhaust unit, used to inject diluent into the gas sampling and quantification unit 30 so that the sampling unit 40 can obtain a diluted sample gas. A containment structure is provided in the reactor building to effectively contain and prevent the leakage of radioactive materials into the environment in the event of a reactor accident or malfunction. It is typically constructed of robust materials capable of withstanding high pressure and high temperature, ensuring that it remains sealed even under extreme conditions. Therefore, in order for the reactor building atmosphere sampling system to sample radioactive gases from the atmosphere after an accident, and to ensure the safe and effective introduction of radioactive gases into the system without compromising the protective performance of the containment structure, an intake unit is required. Simultaneously, since the reactor building atmosphere sampling system itself also requires a closed system to prevent radioactive gases entering the sampling system from leaking outside the containment structure and causing radiation hazards, an exhaust unit is also needed. This exhaust unit vents the gases from the sampling system through the containment structure into the reactor building. The sampling unit 40 is connected to the exhaust unit and is used to contain the sampled gas, ensuring sample integrity. The diluent injection unit 70 is connected to the dilution unit and the exhaust unit, and is used to inject diluent into the gas injection and metering unit 30, so that the sampling unit 40 obtains diluted sample gas. In embodiments of the present invention, it is necessary to ensure that the selected dilution gas does not chemically react with the radioactive gas, causing changes in sample properties, generating new harmful gases, or affecting sample testing. Therefore, an inert gas, such as helium or nitrogen, must be used. Considering cost and the uncontrollable temperature of the sample gas, nitrogen is chosen as the optimal solution. The diluent injection unit 70 can adjust the concentration of the sample gas as needed, facilitating subsequent analysis. To effectively control each unit, module, and component in the reactor building atmosphere sampling system to accurately realize the functions of the sampling and measurement system, a gas sampling system control module 90 is also provided. The gas sampling system control module 90 is electrically connected to each electronic control component, receives feedback from each component for automatic control, and also actively intervenes based on manually input commands.

[0040] The reactor building atmosphere sampling system in this embodiment of the invention enables the dilution and sampling of the reactor building atmosphere outside the reactor building after an accident without damaging the containment structure, thus ensuring the radiation safety of sampling personnel.

[0041] In one embodiment, reference is made to Figure 3 The sampling unit 40 includes a retention bottle and a gas dilution bottle. The input end of the retention bottle is connected to the connection end of the sampling unit 40, and the output end of the retention bottle is connected to the input end of the gas dilution bottle. The output end of the gas dilution bottle is connected to the exhaust unit. The retention bottle refers to the first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412, which are used to capture radioactive aerosol substances and concentrate volatile radioactive substances such as radioactive iodine in the sample gas. The input end of the retention bottle is connected to the connection end of the multi-port valve 301 and the sampling unit 40. When the radioactive gas passes through the connection end of the sampling unit 40, it enters the retention bottle. After the retention bottle washes and filters the radioactive aerosols and radioactive iodine in the sample gas, the gas then enters the input end of the gas dilution bottle and the sampling bottle from the output end of the retention bottle, thus realizing the sampling of the water-washed, filtered and diluted radioactive gas.

[0042] In one embodiment, reference is made to Figure 3The sampling unit 40 also includes a first switching valve 403 with multiple valve ports. The dilution bottles include a first gas dilution bottle 404 and a second gas dilution bottle 407, which have different volumes. The first switching valve 403 is connected to the output end of the retention bottle, the input end of the first gas dilution bottle 404, and the input end of the second gas dilution bottle 407, respectively. The output ends of both the first gas dilution bottle 404 and the second gas dilution bottle 407 are connected to an exhaust unit. The first switching valve 403 can switch the connection between the output end of the retention bottle and the input ends of the first gas dilution bottle 404 and the second gas dilution bottle 407. In order to obtain a larger quantity of dilution gas and ensure that even when the radioactive atmosphere in the reactor building is at extremely high radioactivity, the diluted gas can still be measured normally using a gamma spectrometer in the laboratory, multiple gas dilution bottles of different volumes need to be set in the sampling unit 40, which is connected to a quantitative loop. Therefore, this embodiment includes two gas dilution bottles of different volumes in the sampling unit 40: a first gas dilution bottle 404 and a second gas dilution bottle 407. The first gas dilution bottle 404 has a volume of 100 ml, and the second gas dilution bottle 407 has a volume of 1000 ml. A first switching valve 403 is also provided to switch the sampling pipeline between the gas dilution bottles of different volumes. After 1 ml of a quantitative amount of radioactive gas is transferred to the 100 ml first gas dilution bottle 404, the diluent gas released from the diluent injection unit 70 continuously fills the first gas dilution bottle 404, resulting in a 100-fold dilution of the sample gas. After 1 ml of a quantitative amount of radioactive gas is transferred to the 1000 ml second gas dilution bottle 407, the diluent gas released from the diluent injection unit 70 continuously fills the second gas dilution bottle 407, resulting in a 1000-fold dilution of the sample gas. The configuration of this embodiment makes it easier to obtain sample dilution gas that can be measured and analyzed by a gamma spectrometer when the radioactive atmosphere inside the reactor building is at an extremely high level of radioactivity, reducing invalid sampling and resulting in a higher sampling success rate. It should be emphasized that the third gas dilution bottle 414 has the same volume as the first gas dilution bottle 404, and the fourth gas dilution bottle 417 has the same volume as the second gas dilution bottle 407.

[0043] In one embodiment, reference is made to Figure 3The sampling unit 40 also includes a first gas sampling bottle 411, and a first switching valve 403 is connected to the first gas sampling bottle 411. A gas sampling bottle is used for direct sampling, and a valve port with a switchable sampling channel is configured on the first switching valve 403 connected to the first gas sampling bottle 411. When the radioactivity concentration in the reactor building atmosphere is high, the sampling bottle 411 is connected to the first gas dilution bottle 404, or the sampling bottle 411 is connected to the second gas dilution bottle 407. After the sampling bottle 411 obtains the diluted gas sample, the sampling bottle 411 and the collected diluted gas sample are sent to the laboratory for gamma-ray spectroscopy analysis. When the radioactivity concentration in the reactor building atmosphere is low, samples can also be obtained directly through the first gas sampling bottle 411. This ensures that even when the radioactivity concentration in the reactor building atmosphere is low, samples with sufficient radioactivity activity can still be obtained for testing, preventing inaccurate measurement and analysis results due to excessively low sample concentration. In this embodiment of the invention, the volume of the gas sampling bottle is preferably 14 ml. In practical use, it was found that since the first gas sampling bottle is connected to the first quick connector 401 and the second gas sampling bottle is connected to the second quick connector 410, and neither the first quick connector 401 nor the second quick connector 410 has an external discharge pipeline, a vacuum bottle is selected as the gas sampling bottle. The vacuum gas sampling bottle enables the collection of radioactive gas samples while ensuring that no radioactive gas spillage or leakage occurs. Therefore, the gas sampling bottle and its connected pipeline do not need to be purged before sampling.

[0044] Reference Figure 3Since the gas sampling and quantification unit 30 includes a first quantitative loop 302 and a second quantitative loop 303, each quantitative loop is equipped with an independent sampling module, namely the first quantitative loop sampling module 41 and the second quantitative loop sampling module 42. In the first quantitative sampling module 41, the inlet end of the first aerosol and iodine retention bottle 402 is connected to the No. 306 electric valve 306. The pipelines connected to the inlet and outlet ends of the first aerosol and iodine retention bottle 402 both pass through the first quick connector 401. The outlet end of the first aerosol and iodine retention bottle 402 is connected to the first switching valve 403. The first switching valve 403 is equipped with 5 ports, one of which is a blind port. The other four are respectively connected to the outlet end of the first aerosol and iodine retention bottle 402, the inlet end of the first gas dilution bottle 404, the inlet end of the second gas dilution bottle 407, and the first gas sampling bottle 411. The first gas sampling bottle 411 is connected to the second quick connector 410. The connecting pipe between the second quick connector 410 and the inlet of the first gas dilution bottle 404 and the second gas dilution bottle 407 is equipped with electric valves 406 and 409. Correspondingly, in the second quantitative loop sampling module 42, the second aerosol and iodine retention bottle 412, the third switching valve 413, the third gas dilution bottle 414, the electric valve 415, the electric valve 416, the fourth gas dilution bottle 417, the electric valve 418, the electric valve 419, the fourth quick connector 420, the second gas sampling bottle 421, and the third quick connector 422 are as follows: Figure 3 The positional relationship and function of each component in the first quantitative loop sampling module 41 are similar to those in the first quantitative loop sampling module 41, and will not be elaborated further here.

[0045] In one embodiment, reference is made to Figure 3The exhaust unit includes an injection module 50 and an exhaust module 60. The output end of the injection module 50 is connected to the exhaust module 60. A No. 9 electric valve 09 is provided between the two connecting pipes to control the gas flow and isolate the pipes. The input end of the injection module 50 is connected to the outlet end 30106, the output end of the first gas dilution bottle 404, the output end of the second gas dilution bottle 407, the output end of the second gas dilution bottle 414, and the output end of the second gas dilution bottle 417. The exhaust module 60 is used to allow the gas in the sampling system to pass through the containment and be discharged into the reactor building. The injection module 50 is used to pressurize the gas to be discharged from the sampling system. To allow the gas in the reactor building atmosphere sampling system of this invention to be discharged into the reactor building to reduce radioactive residue and overcome the potential pressure difference between the inside and outside of the containment, an exhaust module 60 passing through the containment and an injection module 50 for gas injection within the pressurization booster system are required. The function of the injection module 50 is mainly realized by a gas injector 501, which is connected to a nitrogen cylinder 503. The nitrogen in the nitrogen cylinder 503 serves as the pressurization and purging gas. A No. 502 electric valve 502 is also installed in the middle of the pipeline connecting the gas injector 501 and the nitrogen cylinder 503 to prevent nitrogen leakage from the nitrogen cylinder 503. When the gas in the reactor building atmosphere sampling system reaches the gas injector 501, the gas injector 501 mixes with nitrogen and performs pressurized injection before being injected into the reactor building atmosphere through the exhaust module 60 and the containment. The exhaust module 60 is also equipped with four electric valves: electric valve 601 (601), electric valve 602 (602), electric valve 603 (603), and electric valve 604 (604). Electric valves 601 and 603 are located inside the containment, while electric valves 602 and 604 are located outside the containment. Electric valve 602 and electric valve 601 are connected along the gas flow direction and form a set of safety control valves controlling the gas discharge from the reactor building's atmospheric sampling system into the containment. When the exhaust module needs to discharge gas, electric valves 601 and 602 will be opened, allowing the gas to escape. However, in the event of a design basis accident or a severe accident, the electric valves are likely to be damaged, especially the No. 601 electric valve 601 and its connected piping located inside the containment. Furthermore, under accident conditions, it is impossible to inspect or replace components and piping inside the containment. To ensure that the sampling system can still normally vent air into the reactor building after an accident, No. 603 electric valve 603 and No. 604 electric valve 604 are installed as redundancies for No. 601 electric valve 601 and No. 602 electric valve 602, ensuring the normal operation of the reactor building atmospheric sampling system.It should be noted that the redundant equipment does not only include electric valves 603 and 604. For electric valves 601 and 602, at least three sets of redundant equipment are usually set to ensure the normal operation of the sampling system. In this embodiment, only one set of redundant equipment is set in the accompanying drawings for illustrative purposes.

[0046] In one embodiment, reference is made to Figure 3The intake unit includes an intake module 10 and a flow control module 20. The input end of the flow control module 20 is connected to the intake module 10, and the output end of the flow control module 20 is connected to the intake end. The intake module 10 is used to allow the atmosphere from the reactor building to pass through the containment vessel and enter the sampling system, while the flow control module 20 is used to control the flow rate of the gas within the sampling system. The intake module 10 and flow control module 20 are configured to ensure the smooth entry of radioactive atmosphere from the reactor building into the sampling system. The intake module 10 is also equipped with four electric valves: electric valve 101 (No. 101), electric valve 102 (No. 102), electric valve 103 (No. 103), and electric valve 104 (No. 104). Electric valves 101 and 103 are located inside the containment vessel, while electric valves 102 and 104 are located outside the containment vessel. Electric valves 101 (No. 101) and 102 (No. 102) are connected along the gas flow direction and form a set of flow safety control valves to control the entry of gas from the containment into the intake module 10. When the intake module 10 requires the entry of radioactive gas, electric valves 101 and 102 will be opened, allowing radioactive gas from the reactor building to enter the intake module 10. However, in the event of a design basis accident or a severe accident, the electric valves are likely to be damaged, especially electric valve 101 and its connected piping located within the containment. Furthermore, under accident conditions, it is impossible to repair or replace components and piping within the containment. To ensure that the sampling system can still normally draw gas from the reactor building after an accident, electric valves 103 (No. 103) and 104 (No. 104) are provided as redundancy for electric valves 101 and 102 to ensure the normal operation of the reactor building atmospheric sampling system. It should be noted that the redundant equipment does not only include electric valves 103 and 104. For electric valves 101 and 102, at least three sets of redundant equipment are typically provided to ensure the normal operation of the sampling system. This embodiment only shows one set of redundant equipment in the accompanying drawings for illustrative purposes. Furthermore, to detect the atmospheric pressure and temperature inside the containment, a pressure sensor 01 and a temperature sensor 02 are also provided at the front end of the air intake module 10. After a design-baseline accident or severe accident, because the reactor is in a state of heat release, the atmosphere inside the reactor building is under high temperature and pressure. A huge pressure difference exists between the sampling system and the atmosphere inside the containment. If the system is directly connected to the atmosphere inside the containment under this high pressure difference, it may cause a high-pressure explosion of the sampling system. To this end, a flow control module 20 was installed, and an electric valve 201 was installed on the connecting pipeline. This electric valve can control the air intake speed when the atmospheric pressure inside the containment is greater than that inside the sampling system, so as to meet the flow rate requirements of the sampling system while protecting the pipeline safety of the sampling system.Following a design-baseline accident or severe accident, and after emergency response and follow-up procedures, the atmosphere inside the reactor building cools down. For safety reasons, the containment vessel remains under negative pressure for an extended period. In this situation, the radioactive gas inside the containment vessel lacks the power to enter the sampling system. Therefore, in the flow control module 20, electric valve 201 (parallel connection) is connected to electric valve 202 (sequential connection), pump 204, and electric valve 203 (sequential connection). Pump 204 provides the power for the radioactive gas from the reactor building atmosphere to enter the sampling system. Electric valves 202 (parallel connection) and 203 (sequential connection) control the flow rate of the radioactive gas. A pressure sensor 03 and a gamma dose rate detector 04 are also sequentially installed on the connecting pipe between the air intake module 10 and the flow control module 20. Pressure sensor 03 is used to monitor the pressure of the pipe section entering the sampling system but before passing through the flow control module 20, thereby providing the control basis for electric valves 201, 202, 204, and 203. The gamma dose rate detector 04 performs online monitoring to initially obtain the radioactivity of the radioactive gas entering the sampling system but before passing through the flow control module 20, providing a basis for the control of the subsequent gas injection and quantification unit 30, diluent injection unit 70, and sampling unit 40.

[0047] This invention also provides a method for sampling the atmosphere of a reactor building, applied to the above-mentioned sampling system for the atmosphere of a reactor building, with reference to... Figure 5 The sampling methods for the atmosphere of the reactor building include:

[0048] S810 controls the multi-way valve 301 to be in injection mode;

[0049] When sampling the sample gas, the multi-way valve 301 must first be switched to the sampling mode so that the quantitative loop can quantitatively sample the radioactive gas entering the reactor building atmosphere from the gas inlet unit 10. Simultaneously, after switching to the sampling mode, the diluent injection unit 70 injects diluent into the multi-way valve 301 to purge the entire sampling pipeline, expelling any residual radioactive gas present in the original sampling system pipeline through the exhaust unit, thereby ensuring the stability and accuracy of the sampling results.

[0050] S820. Open the air intake unit and the exhaust unit to allow the metering loop to quantitatively inject sample gas into the atmosphere of the reactor building.

[0051] After the intake and exhaust units are activated, the sampling system is connected to the atmosphere of the reactor building inside the containment, and the radioactive gas begins to circulate in the sampling system. The quantitative loop begins to quantitatively sample the radioactive gas.

[0052] S830, shut down the intake unit and control the multi-way valve 301 to be in metering mode;

[0053] After completing the quantitative sampling, the air intake unit is closed, so that the sampling system is isolated from the atmosphere of the reactor building inside the containment in the air intake direction. The multi-way valve 301 is switched to quantitative mode to prepare for the quantitative sampling operation.

[0054] S840. Open the diluent injection unit 70 and blow the sample gas in the quantitative loop into the sampling unit 40 to dilute and sample the sample gas.

[0055] The diluent gas injected by the diluent injection unit 70 provides power to blow the sample gas in the quantitative loop into the sampling unit 40, thereby achieving the dilution and sampling of a quantitative sample gas.

[0056] In one embodiment, reference is made to Figure 6 The process of opening the diluent injection unit 70 and blowing the sample gas from the quantitative loop into the sampling unit 40 to dilute and sample the sample gas also includes:

[0057] S841. Open the diluent injection unit 70 and blow the sample gas in the quantitative loop into the sampling unit 40;

[0058] S842. In sampling unit 40, sodium hydroxide solution is used to wash and retain airborne radioactive particles in the sample gas.

[0059] S843. Dilute and sample the gas after it has been treated with sodium hydroxide solution.

[0060] After the diluent injection unit 70 is opened, the sample gas in the metering loop is first blown into the aerosol and iodine retention bottle, which contains sodium hydroxide solution. The sodium hydroxide solution is used to retain airborne radioactive particles in the sample gas, including radioactive aerosol particles and radioactive iodine. The filtered sample gas then enters the gas dilution bottle, and the dilution and sampling are completed during the continuous injection of diluent gas.

[0061] In one embodiment, reference is made to Figure 7 The steps for diluting and sampling the sample gas after it has been treated with sodium hydroxide solution washing and dissolution include:

[0062] S8431. Based on the online gamma dose rate measurement results, select a gas dilution ratio that ensures the radioactivity of the inert gas in the gas sample is below the upper limit of the analyzer.

[0063] S8432a. When the measurement result is greater than the first preset value, dilution and sampling are performed using the first gas dilution bottle 404 and the gas sampling bottle 411.

[0064] S8432b: When the measurement result is less than the first preset value and greater than the second preset value, dilution and sampling are performed using the second gas dilution bottle 407 and the gas sampling bottle 411.

[0065] S8432c: When the measurement result is less than the second preset value, a gas sampling bottle is used for sampling.

[0066] The online gamma dose rate is the gamma dose rate result obtained from the initial measurement of the radioactive gas entering the sampling system pipeline by the gamma dose rate detector 04. The first preset value and the second preset value refer to the pre-set thresholds for switching between the gamma dose rate measurement result and the sampling mode. Based on the gamma dose rate measurement result, the first preset value, and the second preset value, different gas dilution bottles or gas sampling bottles are switched for sampling. The final dilution ratio of the sample changes with the sampling container, ultimately obtaining a gas sample that can be analyzed by a gamma spectrometer in the laboratory.

[0067] S850, shut down the diluent injection unit 70 and the exhaust unit, and obtain gas samples, aerosols and radioactive iodine sodium hydroxide solution samples from the sampling unit 40.

[0068] Finally, after closing the diluent injection unit 70 and the exhaust unit, the electric valves connecting each unit are closed, so that the pipelines connected to the gas dilution bottle or gas sampling bottle are in a closed state and the pipeline pressure does not change. Gas samples are then taken from the gas dilution bottle or gas sampling bottle of the sampling unit 40, and aerosol and sodium hydroxide solution samples of radioactive iodine are obtained from the iodine retention bottle.

[0069] To more clearly illustrate the reactor building atmosphere sampling system and method of the present invention, refer to... Figure 3 and Figure 4 The following example further illustrates this point:

[0070] During normal operation of the power plant, the atmospheric sampling system in the reactor building is shut down after an accident. During a nuclear power plant shutdown and overhaul, the atmospheric sampling system in the reactor building is activated to inspect and test the equipment status and operational reliability. Any component failures during the inspection and testing process are promptly replaced and repaired. In the event of an accident, atmospheric sampling of the reactor building is carried out according to the instructions of the nuclear power plant's emergency command center.

[0071] Upon receiving the atmospheric sampling command from the reactor building, the nuclear power plant's main control room operator remotely controls the opening of electric valves 101 (101), 102 (102), 601 (601), and 602 (602). If any of these electric valves fails to open, the main control room operator will immediately receive an indication signal indicating that the corresponding valve is not open. Upon receiving an indication signal that electric valve 101 or 102 is not open, the operator remotely controls the opening of electric valve 103 or 104 (104); similarly, upon receiving an indication signal that electric valve 601 or 602 is not open, the operator remotely controls the opening of electric valve 603 or 604 (604).

[0072] To reduce the error in the results, the radioactive gas will be sampled multiple times. Therefore, in order to clean the residual radioactive gas in the sampling system pipeline and ensure that the next sampling is not affected, the entire sampling system pipeline must be purged through the diluent injection unit 70.

[0073] Before performing the purging, confirm that the electric valves 201, 202, and 203 of the flow control module 20 and the pump 204 are in the closed state; open the electric valve 502 of the injection module 50 and open the electric valve 09. Connect terminals 1 and 4 of the second switching valve 702, and adjust it so that terminals 1 and 2 are connected. Nitrogen gas from inert gas source 701 is used to purge the gas injection and quantification module 31's injection circuit via electric valve 010. The injection circuit refers to the sequential connection of the inlet 30101 of multi-port valve 301, the first connection 30102 of the first quantification loop, the first quantification loop 302, the second connection 30107 of the first quantification loop, the first connection 30108 of the second quantification loop, the second quantification loop 303, the second connection 30105 of the second quantification loop, and the outlet 30106. The purging flow rate is adjusted to 500 mL / min by electric valve 010 and flow meter 011 to remove residual radioactive gas in the injection circuit. The purging time is 2 minutes. Simultaneously, the electric valves 304, 305, 306, and 307 of the gas injection and quantitative module 31 are opened. The first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412, which do not contain sodium hydroxide solution, in the first quantitative loop 302 sampling module and the second quantitative loop 303 sampling module are respectively connected to the first quick connector 401 and the third quick connector 422. The electric valves 405, 406, 408, 409, 415, 416, 418, and 419 are opened. The first switching valve 403 and the third switching valve 413 are connected at ends 1 and 3.

[0074] After the injection circuit is purged, connect terminals 1 and 2 of the second switching valve 702 and adjust it so that terminals 1 and 3 are connected. Nitrogen from the inert gas source 701 is used to purge the gas injection and quantification module 31, the first quantification loop 302 sampling module, and the second quantification loop 303 sampling module.

[0075] The purging method involves nitrogen from the inert gas source 701 being purged through the gas injection and quantitative module 31 via the following components: electric valve 304 (No. 304), the first dilution unit connection terminal 30104 and the first sampling unit connection terminal 30103 of the multi-port valve 301, electric valve 306 (No. 306), the first quick connector 401 of the sampling module of the first quantitative loop 302, the first aerosol and iodine retention bottle 402, terminals 1 and 3 of the first switching valve 403, electric valves 406 (No. 406) and 409 (No. 409), the first gas dilution bottle 404 (1000mL) and the second gas dilution bottle 407 (100mL), electric valves 405 (No. 405) and 408 (No. 408). Similarly, nitrogen in the inert gas source 701 is purged through another loop via the gas injection and quantitative module 31's No. 305 electric valve 305, the second dilution unit connection terminal 30109 and the second sampling unit connection terminal 30110 of the multi-port valve 301, No. 307 electric valve, the third quick connector 422 of the second quantitative loop 303 sampling module, the second aerosol and iodine retention bottle 412, the first and third terminals of the third switching valve 413, the No. 416 electric valve and the No. 419 electric valve, the third gas dilution bottle 414 (1000mL) and the fourth gas dilution bottle 417 (100mL), the No. 415 electric valve and the No. 418 electric valve. The nitrogen purging flow rate was adjusted to 2500 mL / min by electric valves 304 and 305, flow meter 308, and electric valve 307, and the purging time was 0.5 minutes.

[0076] Connect terminals 1 and 3 of the first switching valve 403 and the third switching valve 413, then adjust the connection so that terminals 1 and 2 are connected. Close electric valves 409 and 419. This purges the circuits of terminals 1 and 2 of the first switching valve 403, the second gas dilution bottle 407 (100mL), and electric valve 408; and the circuits of terminals 1 and 2 of the third switching valve 413, the fourth gas dilution bottle 417 (100mL), and electric valve 418. The purging time is 0.5 minutes.

[0077] Connect terminals 1 and 2 of the first switching valve 403 and the third switching valve 413, then adjust them so that terminals 1 and 4 are connected. Close electric valves 406 and 416. This purges the circuits of terminals 1 and 4 of the first switching valve 403, the first gas dilution bottle 404 (1000mL), and electric valve 405; and the circuits of terminals 1 and 4 of the third switching valve 413, the third gas dilution bottle 414 (1000mL), and electric valve 415. The purging time is 5 minutes.

[0078] The purging gas is finally drawn in by the gas ejector 501 of the injection module 50, injected through electric valve 09, electric valve 602, and electric valve 601, and then injected into the reactor building.

[0079] After purging the gas injection and quantification module 31, the first quantification loop 302 sampling module, and the second quantification loop 303 sampling module, close the electric valves 304, 305, 306, and 307 of the gas injection and quantification module 31. Close the electric valves 405, 406, 408, 409, 415, 416, 418, and 419 of the first quantification loop 302 sampling module and the second quantification loop 303 sampling module. Adjust the first switching valve 403 and the third switching valve 413 to connect terminals 1 and 5 respectively, adjust the second switching valve 702 to connect terminals 1 and 4, and close the electric valve 010.

[0080] Manually remove the first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412, and fill each with 80 mL of 1 mol / L to 2 mol / L sodium hydroxide (NaOH) solution. Connect the first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412, which contain sodium hydroxide solution, to the first quick connector 401 and the third quick connector 422, respectively. Connect the first gas sampling bottle 411 and the second gas sampling bottle 421 to the second quick connector 410 and the fourth quick connector 420, respectively.

[0081] The opening and closing of the aforementioned electric valves, the flow regulation of the electric flow regulating valves, and the control of the five-way valve, four-way valve, and ten-way valve are all controlled by the gas sampling system control module 90.

[0082] On the gas sampling system control module 90, check the measurement results of pressure sensor 03. If the measured value of pressure sensor 03 is higher than 0.25 MPa, open electric valve 201 and confirm that electric valve 202 and pump 204 are closed. If the measured value of pressure sensor 03 is lower than 0.25 MPa, open electric valve 202 and electric valve 203 and pump 204, and confirm that electric valve 201 is closed.

[0083] The opening and closing of the aforementioned electric valves 201 (No. 201), 202 (No. 202), 203 (No. 203), and pump 204 are controlled by the gas sampling system control module 90.

[0084] After the flow control module 20 completes its operation, the No. 10 electric valve 010 is opened, and the measurement data of the No. 1 pressure sensor 01 and the No. 6 pressure sensor 06, the No. 2 temperature sensor 02 and the No. 5 temperature sensor 05 are recorded on the gas sampling system control module 90. The reactor building atmospheric injection flow rate is adjusted to 500 mL / min by the No. 10 electric valve 010 and the No. 11 flow meter 011. The atmosphere from the reactor building enters the gas sampling and quantification unit 30 via the intake module 10 and the flow control module 20. It is introduced through the intake end 30101 of the multi-way valve 301 of the gas sampling and quantification unit 30, and then passes through the first sampling unit connection end 30103, the first quantitative ring 302, the second connection end 30107 of the first quantitative ring, the first connection end 30108 of the second quantitative ring, the second quantitative ring 303, the second connection end 30105 of the second quantitative ring, and the outlet end 30106 to the injection module 50. The gas ejector 501 of the injection module 50 draws in the gas and injects it into the reactor building via the exhaust module 60, thus achieving the purging and injection of atmospheric samples from the reactor building through the first quantitative ring 302 and the second quantitative ring 303. The atmospheric sample purging and injection time is 2 minutes.

[0085] After completing the atmospheric sample introduction from the reactor building, the multi-way valve 301 of the gas sampling and quantitative module 31 is switched from the sampling mode to the quantitative mode on the gas sampling system control module 90. Simultaneously, the flow control module 20 and the No. 10 electric valve 010 are remotely closed, and the recording of measurement data from pressure sensors 01 and 06, and temperature sensors 02 and 05 is stopped. The average value of the measurement data from pressure sensors 01 and 06, and temperature sensors 02 and 05 is automatically calculated during the atmospheric sample introduction process of the gas sampling and quantitative module 31. and ).

[0086] In quantitative mode, the inlet end 30101 and outlet end 30106 of the multi-way valve 301 are connected in series to allow the high-radioactive atmosphere in the reactor building to be discharged into the reactor building through the inlet end 30101, outlet end 30106 and injection module 50. The first dilution unit connection end 30104, the second connection end 30107 of the first quantitative loop, the first quantitative loop 302, the first connection end 30102 of the first quantitative loop and the first sampling unit connection end 30103 are connected in series to form a passage to achieve a quantitative measurement of 1 mL of the atmosphere in the reactor building. Similarly, the second dilution unit connection end 30109, the first connection end 30108 of the second quantitative loop, the second quantitative loop 303, the second connection end 30105 of the second quantitative loop and the second sampling unit connection end 30110 are connected in series to form a passage to achieve a quantitative measurement of 0.1 mL of the atmosphere in the reactor building.

[0087] The above-mentioned multi-way valve 301 for sample injection and quantitative mode adjustment, electric valve opening and closing, and flow electric regulating valve adjustment are all controlled by the gas sampling system control module 90.

[0088] Before sampling atmospheric samples from the reactor building, the following electric valves were checked on the gas sampling system control module 90: 306 (No. 306), 307 (No. 307), 405 (No. 405), 406 (No. 406), 408 (No. 408), 409 (No. 409), 415 (No. 415), 416 (No. 416), 418 (No. 418), and 419 (No. 419). The first switching valve 403 and the third switching valve 413 were both connected at terminals 1 and 5. The measurement data from the gamma dose rate detector 04 were then checked on the gas sampling system control module 90. Measurement data from gamma dose rate detector 04 The sampling procedures for atmospheric samples from reactor buildings differ.

[0089] when At this time, the gas sampling system control module 90 controls the first switching valve 403 and the third switching valve 413 to switch from being connected to terminals 1 and 5 to being connected to terminals 1 and 4. Electric valves 406 and 416 are in the open state. The second switching valve 702 is controlled to switch from being connected to terminals 1 and 4 to being connected to terminals 1 and 3. Electric valves 304 and 305 are opened sequentially. Based on the flow information from flow meters 308 and 309, the flow rate through electric valves 304 and 305 is adjusted to 500 ml / min.

[0090] When electric valves 306 and 307 are opened, the nitrogen in the inert gas source 701 is purged through ends 1 and 3 of the second switching valve 702, electric valves 304 and 305, respectively, to purge the 1 mL and 0.1 mL of high radioactive gas in the reactor building stored in the first metering loop 302 and the second metering loop 303 of the multi-port valve 301 in the metering mode. The high radioactive gas in the reactor building stored in the first metering loop 302 and the second metering loop 303 is then purged through electric valves 306 and 307 to the first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412.

[0091] The 2 mol / L sodium hydroxide solution in the first aerosol and iodine retention bottle 402 retains all the aerosols and iodine in the 1 mL of highly radioactive gas from the reactor building stored in the first quantitative loop 302. The radioactive inert gas and other insoluble gases are then purged into the first gas dilution bottle 404 and the first gas sampling bottle 411. The 2 mol / L sodium hydroxide solution in the second aerosol and iodine retention bottle 412 retains all the aerosols and iodine in the 0.1 mL of highly radioactive gas from the reactor building stored in the second quantitative loop 303. The radioactive inert gas and other insoluble gases are then purged into the third gas dilution bottle 414 and the second gas sampling bottle 421. After 2 minutes of gas purging, the No. 304 electric valve 305 and No. 305 electric valve are remotely closed on the gas sampling system control module 90. The first switching valve 403 and the third switching valve 413 are adjusted from being connected at terminals 1 and 4 to being connected at terminals 1 and 5. The No. 406 electric valve 406 and No. 416 electric valve 416 are closed. At the same time, personnel are arranged to remove the first aerosol and iodine retention bottle 402 and the first gas sampling bottle 411 from the first quick connector 401 and the second quick connector 410 to achieve a 1 mL dilution sampling of the reactor building atmosphere. The second aerosol and iodine retention bottle 412 and the second gas sampling bottle 421 are removed from the third quick connector 422 and the fourth quick connector 420 to achieve a 0.1 mL dilution sampling of the reactor building atmosphere.

[0092] when At that time, the gas sampling system control module 90 controls the first switching valve 403 and the third switching valve 413 to switch from being connected to terminals 1 and 5 to being connected to terminals 1 and 2. It also controls electric valves 409 and 419 to be in the open state, and controls the second switching valve 702 to switch from being connected to terminals 1 and 4 to being connected to terminals 1 and 3. Electric valves 304 and 305 are opened sequentially. Based on the flow information from flow meters 308 and 309, the flow rate through electric valves 304 and 305 is adjusted to 50 ml / min.

[0093] When electric valves 306 and 307 are opened, nitrogen gas in inert gas source 701 passes through ends 1 and 3 of second switching valve 702. Electric valves 304 and 305 purge the 1 mL and 0.1 mL of high radioactive gas in the reactor building stored in the first metering loop 302 and the second metering loop 303 of multi-port valve 301 in metering mode, respectively. The high radioactive gas in the reactor building stored in the first metering loop 302 and the second metering loop 303 is purged through electric valves 306 and 307 to the first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412.

[0094] The 2 mol / L sodium hydroxide solution in the first aerosol and iodine retention bottle 402 completely retains the aerosols and iodine in the 1 mL of highly radioactive gas from the reactor building stored in the first quantitative loop 302. The radioactive inert gas and other insoluble gases are then purged to the second gas dilution bottle 407 and the first gas sampling bottle 411. The 2 mol / L sodium hydroxide solution in the second aerosol and iodine retention bottle 412 completely retains the aerosols and iodine in the 0.1 mL of highly radioactive gas from the reactor building stored in the second quantitative loop 303. The radioactive inert gas and other insoluble gases are then purged to the fourth gas dilution bottle 417 and the second gas sampling bottle 421. After purging for 2 minutes, the No. 304 electric valve 304 and No. 305 electric valve 305 are remotely closed on the gas sampling system control module 90, and the first switching valve 403 and the third switching valve 413 are adjusted from being connected at terminals 1 and 2 to being connected at terminals 1 and 5. Simultaneously, staff members were instructed to remove the first aerosol and iodine retention bottle 402 and the first gas sampling bottle 411 from the first quick connector 401 and the second quick connector 410 to achieve a 1 mL dilution sampling of the reactor building atmosphere; and to remove the second aerosol and iodine retention bottle 412 and the second gas sampling bottle 421 from the third quick connector 422 and the fourth quick connector 420 to achieve a 0.1 mL dilution sampling of the reactor building atmosphere.

[0095] when At that time, the gas sampling system control module 90 controls the first switching valve 403 and the third switching valve 413 to switch from being connected to terminals 1 and 5 to being connected to terminals 1 and 3, and controls the second switching valve 702 to switch from being connected to terminals 1 and 4 to being connected to terminals 1 and 3. Then, the electric valves 304 and 305 are opened sequentially. Based on the flow information from flow meters 308 and 309, the flow rate through electric valves 304 and 305 is adjusted to 5 ml / min.

[0096] Open electric valves 306 and 307. Nitrogen gas in inert gas source 701 passes through ends 1 and 3 of second switching valve 702. Electric valves 304 and 305 purge the 1 mL and 0.1 mL of high radioactive gas in the reactor building stored in the first metering loop 302 and the second metering loop 303 of multi-port valve 301 in metering mode, respectively. The high radioactive gas in the reactor building stored in the first metering loop 302 and the second metering loop is then purged through electric valves 306 and 307 to the first aerosol and iodine retention bottle 402 and the second aerosol and iodine retention bottle 412.

[0097] The 2 mol / L sodium hydroxide solution in the first aerosol and iodine retention bottle 402 completely retains the aerosols and iodine in the 1 mL of highly radioactive gas from the reactor building stored in the first quantitative loop 302. The radioactive inert gas and other insoluble gases are then purged into the first gas sampling bottle 411. The 2 mol / L sodium hydroxide solution in the second aerosol and iodine retention bottle 412 completely retains the aerosols and iodine in the 0.1 mL of highly radioactive gas from the reactor building stored in the second quantitative loop 303. The radioactive inert gas and other insoluble gases are then purged into the second gas sampling bottle 421. After purging for 3 minutes, the No. 304 electric valve 304 and No. 305 electric valve 305 are remotely closed on the gas sampling system control module 90, and the first switching valve 403 and the third switching valve 413 are adjusted from being connected at terminals 1 and 3 to being connected at terminals 1 and 5. Simultaneously, staff members were instructed to remove the first aerosol and iodine retention bottle 402 and the first gas sampling bottle 411 from the first quick connector 401 and the second quick connector 410 to achieve a 1 mL sample of the reactor building atmosphere; and to remove the second aerosol and iodine retention bottle 412 and the second gas sampling bottle 421 from the third quick connector 422 and the fourth quick connector 420 to achieve a 0.1 mL sample of the reactor building atmosphere.

[0098] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A gas sampling and quantification module, characterized in that, include: At least a certain number of loops are used for quantitative sampling of sample gas, wherein the at least a certain number of loops are a first quantitative loop and a second quantitative loop; A multi-way valve includes an inlet end and an outlet end, and at least one set of metering loop connection end groups. The metering loop connection end groups include a first metering loop connection end and a second metering loop connection end, a dilution unit connection end and a sampling unit connection end. The at least one set of metering loop connection end groups is a first set of metering loop connection end groups and a second set of metering loop connection end groups corresponding to the first metering loop and the second metering loop. In the sample injection mode, the air inlet, the first connection end of the first quantitative loop, the first quantitative loop, the second connection end of the first quantitative loop, the first connection end of the second quantitative loop, the second quantitative loop, the second connection end of the second quantitative loop, and the air outlet are connected in sequence. In quantitative mode, the first dilution unit connection end, the first quantitative loop second connection end, the first quantitative loop, the first quantitative loop first connection end, and the first sampling unit connection end are connected in sequence, and the second dilution unit connection end, the second quantitative loop first connection end, the second quantitative loop, the second quantitative loop second connection end, and the second sampling unit connection end are connected in sequence.

2. A sampling system for the atmosphere of a reactor building, characterized in that, include: A gas injection and quantification unit, including the gas injection and quantification module according to claim 1; An air intake unit, connected to the air intake end, is used to allow the atmosphere from the reactor building to pass through the containment structure and enter the sampling system. An exhaust unit is connected to the gas outlet end, and the exhaust unit is used to allow the gas in the sampling system to pass through the containment and be discharged into the reactor building. A sampling unit is connected to the sampling unit connection terminal and the exhaust unit, and the sampling unit is used to contain the sample gas to be sampled; A diluent injection unit is connected to the dilution unit connection terminal and the exhaust unit. The diluent injection unit is used to inject diluent into the gas injection and quantification unit so that the sampling unit can obtain diluted sample gas.

3. The reactor building atmosphere sampling system according to claim 2, characterized in that, The sampling unit includes a retention bottle and a gas dilution bottle. The input end of the retention bottle is connected to the connection end of the sampling unit, the output end of the retention bottle is connected to the input end of the gas dilution bottle, and the output end of the gas dilution bottle is connected to the exhaust unit.

4. The reactor building atmosphere sampling system according to claim 3, characterized in that, The sampling unit further includes a first switching valve with multiple valve ports. The dilution bottle includes a first gas dilution bottle and a second gas dilution bottle, which have different volumes. The first switching valve is connected to the output end of the stagnation bottle, the input end of the first gas dilution bottle, and the input end of the second gas dilution bottle, respectively. The output ends of both the first and second gas dilution bottles are connected to the exhaust unit. The first switching valve can switch the connection between the output end of the stagnation bottle and the input ends of the first and second gas dilution bottles.

5. The reactor building atmosphere sampling system according to claim 4, characterized in that, The sampling unit also includes a first gas sampling bottle, and the first switching valve is also connected to the first gas sampling bottle.

6. The reactor building atmosphere sampling system according to claim 4, characterized in that, The exhaust unit includes an injection module and an exhaust module. The output end of the injection module is connected to the exhaust module, and the input end of the injection module is connected to the outlet end, the output end of the first gas dilution bottle, and the output end of the second gas dilution bottle. The exhaust module is used to allow the gas in the sampling system to pass through the containment vessel and be discharged into the reactor building. The injection module is used to pressurize the gas to be discharged from the sampling system.

7. The sampling system for the atmosphere of the reactor building according to any one of claims 2 to 6, characterized in that, The air intake unit includes an air intake module and a flow control module. The input end of the flow control module is connected to the air intake module, and the output end of the flow control module is connected to the air intake end. The air intake module is used to allow the atmosphere of the reactor building to pass through the containment vessel and enter the sampling system, and the flow control module is used to control the flow rate of the gas in the sampling system.

8. The reactor building atmosphere sampling system according to claim 7, characterized in that, The diluent injection unit includes an inert gas source and a second switching valve, the second switching valve being connected to the inert gas source, the inlet, the dilution unit connection end, and the outlet.

9. A method for sampling the atmosphere of a reactor building, characterized in that, A sampling system for the atmosphere of a reactor building according to any one of claims 2 to 8, comprising: Control the multi-way valve to be in the injection mode; The air intake unit and the air exhaust unit are turned on, so that the metering loop can quantitatively inject sample gas into the atmosphere of the reactor building; The intake unit is closed, and the multi-way valve is controlled to be in the metering mode; Open the diluent injection unit and blow the sample gas in the quantitative loop into the sampling unit to dilute and sample the sample gas; The diluent injection unit and the exhaust unit are shut down, and a gas sample is obtained from the sampling unit.

10. The method for sampling the atmosphere of a reactor building according to claim 9, characterized in that, The step of opening the diluent injection unit and blowing the sample gas in the quantitative loop into the sampling unit to dilute and sample the sample gas includes: Open the diluent injection unit and blow the sample gas from the quantitative loop into the sampling unit; In the sampling unit, sodium hydroxide solution is used to wash and retain airborne radioactive particles in the sample gas; The sample gas was diluted and sampled after being treated with sodium hydroxide solution.

11. The method for sampling the atmosphere of a reactor building according to claim 10, characterized in that, The step of diluting and sampling the sample gas after treatment with sodium hydroxide solution washing and dissolution technology includes: Based on the online gamma dose rate measurement results, select a gas dilution ratio that ensures the radioactivity of the inert gas in the gas sample is below the upper limit of the analyzer. When the measurement result is greater than the first preset value, dilution and sampling are performed using a first gas dilution bottle and a gas sampling bottle. When the measurement result is less than the first preset value and greater than the second preset value, dilution and sampling are performed using a second gas dilution bottle and a gas sampling bottle. If the measurement result is less than the second preset value, a gas sampling bottle is used to take a sample directly.

Images