Radioactive inert gas detection device

Abstract

The invention discloses a radioactive inert gas detection device which comprises a gas chamber, a plastic flash detection assembly used for detecting the total beta activity concentration of radioactive inert gas, and a lanthanum bromide crystal detection assembly used for detecting the types of radionuclides in the radioactive inert gas and the activity concentration of the radionuclides. The plastic flashover detection assembly comprises a first plastic flashover detector, a second plastic flashover detector, a third plastic flashover detector and a first signal processing circuit board. The bottom of the third plastic flashover detector is provided with a lead shielding plate. The lanthanum bromide crystal detection assembly comprises a first lanthanum bromide crystal detector, a second lanthanum bromide crystal detector and a second signal processing circuit board; lead shielding plates are arranged on the first lanthanum bromide crystal detector, the second lanthanum bromide crystal detector and the tops of the first lanthanum bromide crystal detector and the second lanthanum bromide crystal detector. The device can overcome environmental background interference, improves the detection efficiency, and can accurately measure the total beta activity concentration of the radioactive inert gas in the exhaust pipeline and the types and activity concentrations of all radionuclides under the condition that the activity concentration of the radioactive inert gas is low.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear radiation monitoring, in particular to a radioactive inert gas detection device. Background Art

[0002] During the operation of a nuclear power plant, radioactive gases are produced due to the fission of U-235 and the decay of fission fragments. Among them, radioactive inert gases account for a high proportion. Radioactive inert gases generally contain radioactive nuclides such as Kr-85, Xe-133, Ke-88 and Xe-135. These radioactive inert gases containing multiple radioactive nuclides will be brought into the secondary circuit along with the steam generator.

[0003] In the prior art, it is necessary to arrange monitoring equipment for measuring radioactive inert gas in the exhaust pipe of the secondary loop. However, the activity concentration of radioactive inert gas in the exhaust pipe is relatively low. In nuclear power plants with high gamma dose rates or large fluctuations in environmental doses, which are subject to large interference from environmental background, the detection efficiency of traditional sodium iodide inert gas detectors is low, and it is impossible to accurately measure the activity concentration of inert gas at low concentrations, nor to accurately distinguish various radionuclides in the gas. Summary of the invention

[0004] Based on this, it is necessary to provide a radioactive inert gas detection device to address the above-mentioned technical problems, which can overcome environmental background interference, improve detection efficiency, and accurately measure the total β activity concentration of radioactive inert gases in the exhaust pipe and the types and activity concentrations of each radioactive nuclide when the activity concentration of the radioactive inert gas is low.

[0005] The present invention provides a radioactive inert gas detection device, comprising:

[0006] a gas chamber connected to an exhaust pipeline containing radioactive inert gas;

[0007] A plastic flash detection assembly is arranged at the top of the gas chamber and is used to detect the total beta activity concentration of the radioactive noble gas;

[0008] A lanthanum bromide crystal detection assembly is disposed at the bottom of the gas chamber and is used to detect the type of each radionuclide and the activity concentration of each radionuclide in the radioactive inert gas;

[0009] The plastic flash detection assembly includes a first plastic flash detector, a second plastic flash detector, a third plastic flash detector and a first signal processing circuit board, and a first lead shielding plate is arranged at the bottom of the third plastic flash detector;

[0010] The first signal processing circuit board is used to calculate a first total β activity concentration of the radioactive inert gas after deducting the environmental background based on the received signals of the first plastic flash detector and the second plastic flash detector using a threshold discrimination method, calculate a second total β activity concentration of the radioactive inert gas after deducting the environmental background based on the received signals of the second plastic flash detector and the third plastic flash detector using a current integration method, and determine a final total β activity concentration of the radioactive inert gas based on the first total β activity concentration and the second total β activity concentration.

[0011] In one embodiment, the lanthanum bromide crystal detection assembly includes a first lanthanum bromide crystal detector, a second lanthanum bromide crystal detector, and a second signal processing circuit board;

[0012] A second lead shielding plate is arranged between the first lanthanum bromide crystal detector and the second lanthanum bromide crystal detector, a third lead shielding plate is arranged on the top of the second lanthanum bromide crystal detector, and the second shielding lead plate is vertically and fixedly connected to the third shielding lead plate;

[0013] The second signal processing circuit board is used for calculating and outputting the types of various radionuclides and the activity concentrations of various radionuclides after deducting the environmental background according to the signals of the first lanthanum bromide crystal detector and the second lanthanum bromide crystal detector.

[0014] In one embodiment, the first plastic flash detector and the second plastic flash detector have different ranges and partially overlap.

[0015] In one embodiment, the radioactive inert gas detection device is further provided with a first fixing frame, a second fixing frame, a support seat and a top cover, wherein the first fixing frame and the second fixing frame are fixedly connected to the upper and lower sides of the gas chamber respectively, the support seat is fixedly connected to the bottom of the second fixing frame, and the top cover is fixedly connected to the top of the first fixing frame;

[0016] The top cover and the support seat are both box-type structures without a cover, and the openings of the top cover and the support seat are both facing the gas chamber.

[0017] In one embodiment, the gas chamber is provided with a cylindrical body, a first carbon fiber plate and a second carbon fiber plate, and the first carbon fiber plate and the second carbon fiber plate are horizontally fixedly assembled on the top and the bottom of the body respectively.

[0018] In one embodiment, the first fixing frame has an installation cavity inside, the plastic flash detection assembly is further provided with a cover plate, the cover plate is fixedly connected to the top of the first fixing frame, the scintillator parts of the first plastic flash detector, the second plastic flash detector and the third plastic flash detector are respectively arranged in the installation cavity inside the first fixing frame, the cover plate is provided with three first assembly holes, and the shell parts of the first plastic flash detector, the second plastic flash detector and the third plastic flash detector are respectively inserted into one of the first assembly holes;

[0019] The first signal processing circuit board is fixedly connected to the top of the cover plate.

[0020] In one embodiment, the lanthanum bromide crystal detection assembly is further provided with a mounting plate, the mounting plate is vertically fixedly connected to the inner wall of the support base, and the second signal processing circuit board is fixedly connected to the bottom of the mounting plate;

[0021] The mounting plate is provided with two second assembly holes, and the first lanthanum bromide crystal detector and the second lanthanum bromide crystal detector are fixedly assembled in one of the second assembly holes respectively.

[0022] In one embodiment, the radioactive inert gas detection device is further provided with an air inlet pipe and an air outlet pipe, one end of the air inlet pipe and the air outlet pipe are connected to the gas chamber, and the other end of the air inlet pipe and the air outlet pipe are connected to the exhaust pipeline where the radioactive inert gas is located.

[0023] In one embodiment, the radioactive noble gas detection device is further provided with a first source detection bracket, a second source detection bracket and a third source detection bracket, a main wall surface of the gas chamber is provided with a first source support hole, and a side wall of the base is provided with a second source support hole and a third source support hole in an axial direction;

[0024] The first source inspection bracket, the second source inspection bracket and the third source inspection bracket are respectively inserted into the first source support hole, the second source support hole and the third source support hole;

[0025] The bracket of the first source detection bracket is located inside the gas chamber, and the brackets of the second source detection bracket and the third source detection bracket are located above the first lanthanum bromide crystal detector and the second lanthanum bromide crystal detector inside the base.

[0026] In one embodiment, the thickness of the first lead shielding plate is 0.8 mm to 1.2 mm, and the thickness of the second shielding lead plate and the third shielding lead plate are both 9 mm to 11 mm.

[0027] The beneficial effects of the present invention are:

[0028] (1) A first lead shielding plate is arranged at the bottom of the third plastic scintillation detector of the present invention, a second lead shielding plate is arranged between the first lanthanum bromide crystal detector and the second lanthanum bromide crystal detector, and a third lead shielding plate is arranged on the top of the second lanthanum bromide crystal detector. The lead shielding plate can shield the radiation of radioactive inert gas. The third plastic scintillation detector and the second lanthanum bromide crystal detector can measure the environmental background. When calculating the total β activity concentration, the first signal processing circuit board can remove the environmental background interference based on the measurement results of the first plastic scintillation detector and the second plastic scintillation detector. The second signal processing circuit board can remove the environmental background interference based on the measurement results of the first lanthanum bromide crystal detector, thereby improving the detection efficiency.

[0029] (2) The radioactive inert gas detection device of the present invention has a plastic flash detection component and a lanthanum bromide crystal detection component respectively disposed at the top and bottom of the gas chamber, and the environmental background is removed during signal processing, so that the total β activity concentration of the radioactive inert gas in the exhaust pipe and the type and activity concentration of each radioactive nuclide can be accurately measured simultaneously.

[0030] (3) In the present invention, the measuring ranges of the first plastic flash detector and the second plastic flash detector are different and partially overlap, thereby improving the measuring range of the entire plastic flash detection assembly. In addition, the signal processing methods of the first plastic flash detector and the second plastic flash detector are different, and the detection results in the overlapping part of the measuring range can be verified with each other, which is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of a radioactive noble gas detection device provided in an embodiment of the present invention;

[0032] Figure 2 A schematic structural diagram of a radioactive noble gas detection device from another angle provided in an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of the structure of the radioactive inert gas detection device provided in an embodiment of the present invention without the top cover and the support base;

[0034] Figure 4 It is a schematic diagram of the assembly relationship between the plastic flash detection component and the gas chamber;

[0035] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure along the AA plane.

[0036] Explanation of the reference numerals: 100, gas chamber; 110, main body; 120, first carbon fiber plate; 130, second carbon fiber plate; 140, air inlet pipe; 150, air outlet pipe; 210, first plastic flash detector; 220, second plastic flash detector; 230, third plastic flash detector; 240, first signal processing circuit board; 250, first lead shielding plate; 260, cover plate; 310, first lanthanum bromide crystal detector; 320, second lanthanum bromide crystal detector; 330, second signal processing circuit board; 340, second lead shielding plate; 350, third shielding lead plate; 360, mounting plate; 410, first fixing frame; 420, second fixing frame; 500, supporting seat; 600, top cover; 700, first source detection bracket; 710, second source detection bracket; 720, third source detection bracket; 800, mounting ear; 900, pad. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] It should be noted that in the description of the present invention, “upper”, “lower”, “top”, “bottom”, orientation or position relationship is based on the attached Figure 1 Regarding the orientation or positional relationship shown, it should be understood that these orientation terms are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0039] In one embodiment, Figure 1 , Figure 2 and Figure 3 As shown, the radioactive inert gas detection device of this embodiment includes:

[0040] The gas chamber 100 is connected to the exhaust pipeline where the radioactive inert gas is located; the plastic flash detection component is arranged at the top of the gas chamber 100, and is used to detect the total β activity concentration of the radioactive inert gas; the lanthanum bromide crystal detection component is arranged at the bottom of the gas chamber 100, and is used to detect the type of each radioactive nuclide and the activity concentration of each radioactive nuclide in the radioactive inert gas.

[0041] In the radioactive inert gas detection device of this embodiment, a plastic scintillation detection component and a lanthanum bromide crystal detection component are respectively arranged at the top and the bottom of the gas chamber 100, and can simultaneously measure the total β activity concentration of the radioactive inert gas in the exhaust pipe and the type and activity concentration of each radioactive nuclide.

[0042] Among them, Figure 4 and Figure 5 As shown, the plastic flash detection assembly includes a first plastic flash detector 210, a second plastic flash detector 220, a third plastic flash detector 230 and a first signal processing circuit board 240, and a first lead shielding plate 250 is arranged at the bottom of the third plastic flash detector 230.

[0043] In this embodiment, the thickness of the first lead shielding plate 250 is 0.8 mm to 1.2 mm. The first lead shielding plate 250 can effectively shield the radiation of the radioactive inert gas in the gas chamber 100 to the third plastic flash detector 230, so the third plastic flash detector 230 can only measure the environmental background interference.

[0044] In this embodiment, the first signal processing circuit board 240 is used to calculate the first total β activity concentration of the radioactive inert gas after deducting the environmental background based on the received signals of the first plastic flash detector 210 and the second plastic flash detector 220 using a threshold discrimination method, calculate the second total β activity concentration of the radioactive inert gas after deducting the environmental background based on the received signals of the second plastic flash detector 220 and the third plastic flash detector 230 using a current integration method, and determine the final total β activity concentration of the radioactive inert gas based on the first total β activity concentration and the second total β activity concentration.

[0045] It should be noted that, since the plastic flash detector can measure both β radiation and γ radiation, that is, the plastic flash detection component of this embodiment can measure two types of radiation, the first signal circuit board 240 of this embodiment needs to remove γ interference when processing the received signal.

[0046] Specifically, the threshold identification method includes four steps of threshold identification, pulse counting, background compensation and activity calculation, and the current integration method includes three steps of current integration, background compensation and activity meter. It should be noted that the specific implementation process of the above steps is well known to those skilled in the art and will not be repeated here.

[0047] In this embodiment, the measurement ranges of the first plastic flash detector 210 and the second plastic flash detector 220 are different and partially overlap. Therefore, the combined measurement range of the first plastic flash detector 210 and the third plastic flash detector 230 after the environmental background is deducted using the threshold identification method and the combined measurement range of the second plastic flash detector 220 and the third plastic flash detector 230 after the environmental background is deducted using the current integration method are also different and partially overlap.

[0048] For example, the first plastic flash detector 210 and the third plastic flash detector 230 jointly complete the first total β activity concentration measurement in the radioactive inert gas in the range of 3.7E+03Bq / m3 to 3.7E+09Bq / m3, and the second plastic flash detector 220 and the third plastic flash detector 230 jointly complete the second total β activity concentration measurement in the range of 3.7E+07Bq / m3 to 3.7E+12Bq / m3.

[0049] In this embodiment, when the first signal processing circuit board 240 performs signal processing, if the first total β activity concentration and the second total β activity concentration measured by the two methods are the same, the same value is the final total β activity concentration; if the first plastic flash detector 210 or the third plastic flash detector 230 finally measures only the first total β activity concentration or the second total β activity concentration due to the first plastic flash detector 210 or the third plastic flash detector 230 exceeding the measurement range, the measured activity concentration is the final total β activity concentration. Using plastic flash detectors with different ranges to measure the total β activity concentration based on different methods can not only verify each other, but also improve the range of the plastic flash detection component.

[0050] In one embodiment, the lanthanum bromide crystal detection assembly includes a first lanthanum bromide crystal detector 310, a second lanthanum bromide crystal detector 320, and a second signal processing circuit board 330;

[0051] A second lead shielding plate 340 is disposed between the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320, a third lead shielding plate is disposed on the top of the second lanthanum bromide crystal detector 320, and the second shielding lead plate is vertically and fixedly connected to the third shielding lead plate 350. The thickness of the second shielding lead plate and the third shielding lead plate 350 are both 9 mm to 11 mm.

[0052] The light yield of lanthanum bromide crystal is 63000photons / MeVγ. Using lanthanum bromide crystal can improve the light yield of scintillating materials, which also improves the detection efficiency of crystal detectors. Luminescence decay time refers to the process in which the luminescence intensity of a luminescent body gradually decreases over time after the excitation stops. The luminescence decay time of lanthanum bromide is 16.4ns. A shorter luminescence decay time means that the lanthanum bromide crystal detector has a higher energy resolution at high count rates.

[0053] The second shielding lead plate and the third shielding lead plate 350 can shield the radiation of the radioactive inert gas to the second lanthanum bromide crystal detector 320, so the radiation of the second lanthanum bromide crystal detector 320 can only measure the environmental background interference. When the second signal processing circuit board 330 processes the signals of the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320, it can remove the environmental background interference based on the measurement results of the first lanthanum bromide crystal detector 310.

[0054] The second signal processing circuit board 330 is used to calculate and output the types of various radionuclides and the activity concentrations of various radionuclides after deducting the environmental background according to the signals of the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320 .

[0055] Specifically, when processing the signals of the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320, the second signal processing circuit board 330 first performs signal shaping nuclear pulse amplitude resolution on the signals of the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320, respectively, then performs energy spectrum compensation on the two pulse amplitude resolved data, and finally performs activity calculation.

[0056] This embodiment eliminates the environmental background when calculating the total β activity concentration of the radioactive noble gas and the type and activity concentration of each radioactive nuclide, thereby avoiding the influence of the environmental background on the measurement results and improving the efficiency and accuracy of nuclear radiation detection of low-concentration radioactive noble gases.

[0057] In one embodiment, the radioactive inert gas detection device is further provided with a first fixing frame 410, a second fixing frame 420, a support seat 500 and a top cover 600, the first fixing frame 410 and the second fixing frame 420 are fixedly connected to the upper and lower sides of the gas chamber 100 respectively, the support seat 500 is fixedly connected to the bottom of the second fixing frame 420, and the top cover 600 is fixedly connected to the top of the first fixing frame 410;

[0058] Specifically, the top cover 600 and the support base 500 are both box-type structures without a cover, and the openings of the top cover 600 and the support base 500 are both facing the gas chamber 100. The internal space of the top cover 600 and the support base 500 can provide assembly space for the plastic flash detection component and the lanthanum bromide crystal detection component. Four legs or universal wheels can be set at the bottom of the support base 500.

[0059] In addition, the first fixing frame 410 and the second fixing frame 420 of this embodiment may also be installed with a hanging lug 800 and a cushion 900 to assist in the fixed installation of the entire radioactive inert gas detection device.

[0060] In one embodiment, the gas chamber 100 is provided with a cylindrical body 110, a first carbon fiber plate 120 and a second carbon fiber plate 130, and the first carbon fiber plate 120 and the second carbon fiber plate 130 are horizontally fixedly assembled on the top and the bottom of the body 110 respectively.

[0061] It should be noted that, since carbon materials can neither shield nor absorb nuclear radiation, the first carbon fiber plate 120 and the second carbon fiber plate 130 arranged above and below the gas chamber 100, while being able to form a sealed gas chamber 100, are beneficial for the nuclear radiation of the radioactive inert gas in the gas chamber 100 to be transmitted to the plastic flash detection component and the lanthanum bromide crystal detection component.

[0062] In one embodiment, the first fixed frame 410 has an installation cavity inside, and the plastic flash detection assembly is also provided with a cover plate 260, which is fixedly connected to the top of the first fixed frame 410. The scintillator parts of the first plastic flash detector 210, the second plastic flash detector 220 and the third plastic flash detector 230 are respectively arranged in the installation cavity inside the first fixed frame 410. The cover plate 260 is provided with three first assembly holes, and the shell parts of the first plastic flash detector 210, the second plastic flash detector 220 and the third plastic flash detector 230 are respectively inserted into a first assembly hole; the first signal processing circuit board 240 is fixedly connected to the top of the cover plate 260.

[0063] Specifically, the interior of the installation cavity can be separated into three parts, which are respectively used to assemble the scintillator parts of different plastic scintillation detectors. The cover plate 260 and the base are used to fix the three plastic scintillation detectors and the first signal processing circuit board 240.

[0064] It should be noted that, under the premise of the same scintillator material, different structural dimensions of the scintillator will result in different measuring ranges of the scintillator. In this embodiment, it is preferred that the first plastic flash detector 210 and the second plastic flash detector 220 have the same structural dimensions, and the size of the third plastic flash detector 230 is smaller than the size of the first plastic flash detector 210 or the second plastic flash detector 220.

[0065] In one embodiment, the lanthanum bromide crystal detection assembly is also provided with a mounting plate 360, which is vertically fixedly connected to the inner wall of the support base 500, and the second signal processing circuit board 330 is fixedly connected to the bottom of the mounting plate 360; the mounting plate 360 ​​is provided with two second assembly holes, and the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320 are respectively fixedly assembled in one second assembly hole.

[0066] The function of the mounting plate 360 ​​is to fix the lanthanum bromide crystal detector inside the support base 500 , that is, at the bottom of the gas chamber 100 , and to provide an assembly space for the second signal processing circuit board 330 .

[0067] In this embodiment, the cover plate 260 and the mounting plate 360 ​​are made of stainless steel, which can prevent radiation from damaging sensitive components on the first signal processing circuit board 240 and the second signal processing circuit board 330. The top cover 600 and the support seat 500, the main body 110 of the gas chamber 100, the first bracket and the second bracket are all made of stainless steel, which can isolate the radiation of the radioactive inert gas in the gas chamber 100.

[0068] In one embodiment, the radioactive inert gas detection device is further provided with an air inlet pipe 140 and an air outlet pipe 150, one end of the air inlet pipe 140 and the air outlet pipe 150 are connected to the gas chamber 100, and the other end of the air inlet pipe 140 and the air outlet pipe 150 are connected to the exhaust pipeline where the radioactive inert gas is located.

[0069] In one embodiment, the radioactive inert gas detection device is further provided with a first source detection bracket 700, a second source detection bracket 710 and a third source detection bracket 720, a first source support hole is penetrated through the wall surface of the main body 110 of the gas chamber 100, and a second source support hole and a third source support hole are axially penetrated through a side wall of the base; the first source detection bracket 700, the second source detection bracket 710 and the third source detection bracket 720 are respectively inserted into the first source support hole, the second source support hole and the third source support hole; the bracket of the first source detection bracket 700 is located inside the gas chamber 100, and the brackets of the second source detection bracket 710 and the third source detection bracket 720 are located above the first lanthanum bromide crystal detector 310 and the second lanthanum bromide crystal detector 320 inside the base.

[0070] In this embodiment, the first source detection bracket 700 can be used to place other sources to be detected, and the second source detection bracket 710 and the third source detection bracket 720 can be used to place other sources to be detected, and can also be used to place attenuation layers to prevent high activity concentration from causing detector count saturation.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A radioactive noble gas detection device, characterized in that: include: The gas chamber (100) is connected to an exhaust pipeline containing radioactive inert gas; A plastic flash detection assembly, arranged at the top of the gas chamber (100), for detecting the total beta activity concentration of the radioactive noble gas; A lanthanum bromide crystal detection assembly is arranged at the bottom of the gas chamber (100) and is used to detect the type of each radioactive nuclide and the activity concentration of each radioactive nuclide in the radioactive inert gas; The plastic flash detection assembly comprises a first plastic flash detector (210), a second plastic flash detector (220), a third plastic flash detector (230) and a first signal processing circuit board (240); a first lead shielding plate (250) is provided at the bottom of the third plastic flash detector (230); The first signal processing circuit board (240) is used to calculate a first total β activity concentration of the radioactive noble gas after deducting the environmental background based on the received signals of the first plastic flash detector (210) and the second plastic flash detector (220) by using a threshold discrimination method, calculate a second total β activity concentration of the radioactive noble gas after deducting the environmental background based on the received signals of the second plastic flash detector (220) and the third plastic flash detector (230) by using a current integration method, and determine a final total β activity concentration of the radioactive noble gas based on the first total β activity concentration and the second total β activity concentration.

2. The radioactive noble gas detection device according to claim 1, characterized in that: The lanthanum bromide crystal detection assembly comprises a first lanthanum bromide crystal detector (310), a second lanthanum bromide crystal detector (320) and a second signal processing circuit board (330); A second lead shielding plate (340) is arranged between the first lanthanum bromide crystal detector (310) and the second lanthanum bromide crystal detector (320), a third lead shielding plate is arranged on the top of the second lanthanum bromide crystal detector (320), and the second shielding lead plate is vertically and fixedly connected to the third shielding lead plate (350); The second signal processing circuit board (330) is used to calculate and output the types of each radionuclide and the activity concentration of each radionuclide after deducting the environmental background based on the signals of the first lanthanum bromide crystal detector (310) and the second lanthanum bromide crystal detector (320).

3. The radioactive noble gas detection device according to claim 2, characterized in that: The first plastic flash detector (210) and the second plastic flash detector (220) have different measuring ranges and partially overlap.

4. The radioactive noble gas detection device according to claim 3, characterized in that: The radioactive inert gas detection device is also provided with a first fixing frame (410), a second fixing frame (420), a support seat (500) and a top cover (600), wherein the first fixing frame (410) and the second fixing frame (420) are respectively fixedly connected to the upper and lower sides of the gas chamber (100), the support seat (500) is fixedly connected to the bottom of the second fixing frame (420), and the top cover (600) is fixedly connected to the top of the first fixing frame (410); The top cover (600) and the support seat (500) are both box-type structures without a cover, and the openings of the top cover (600) and the support seat (500) are both facing the gas chamber (100).

5. The radioactive noble gas detection device according to claim 4, characterized in that: The gas chamber (100) is provided with a cylindrical main body (110), a first carbon fiber plate (120) and a second carbon fiber plate (130), wherein the first carbon fiber plate (120) and the second carbon fiber plate (130) are respectively fixedly mounted horizontally on the top and the bottom of the main body (110).

6. The radioactive noble gas detection device according to claim 5, characterized in that: The first fixing frame (410) has an installation cavity inside, and the plastic flash detection assembly is further provided with a cover plate (260), and the cover plate (260) is fixedly connected to the top of the first fixing frame (410), and the scintillator parts of the first plastic flash detector (210), the second plastic flash detector (220) and the third plastic flash detector (230) are respectively arranged in the installation cavity inside the first fixing frame (410), and the cover plate (260) is provided with three first assembly holes, and the shell parts of the first plastic flash detector (210), the second plastic flash detector (220) and the third plastic flash detector (230) are respectively inserted into one of the first assembly holes; The first signal processing circuit board (240) is fixedly connected to the top of the cover plate (260).

7. The radioactive noble gas detection device according to claim 6, characterized in that: The lanthanum bromide crystal detection assembly is also provided with a mounting plate (360), the mounting plate (360) is vertically fixedly connected to the inner wall of the support seat (500), and the second signal processing circuit board (330) is fixedly connected to the bottom of the mounting plate (360); The mounting plate (360) is provided with two second assembly holes, and the first lanthanum bromide crystal detector (310) and the second lanthanum bromide crystal detector (320) are respectively fixedly assembled in one of the second assembly holes.

8. The radioactive noble gas detection device according to claim 7, characterized in that: The radioactive inert gas detection device is also provided with an air inlet pipe (140) and an air outlet pipe (150), one end of each of the air inlet pipe (140) and the air outlet pipe (150) is connected to the gas chamber (100), and the other end of each of the air inlet pipe (140) and the air outlet pipe (150) is connected to an exhaust pipeline where the radioactive inert gas is located.

9. The radioactive noble gas detection device according to claim 8, characterized in that: The radioactive inert gas detection device is further provided with a first source detection bracket (700), a second source detection bracket (710) and a third source detection bracket (720); a first source support hole is provided through the wall surface of the main body (110) of the gas chamber (100); and a second source support hole and a third source support hole are provided through the axial direction of one side wall of the base; The first source inspection bracket (700), the second source inspection bracket (710) and the third source inspection bracket (720) are respectively inserted into the first source support hole, the second source support hole and the third source support hole; The bracket of the first source detection bracket (700) is located inside the gas chamber (100), and the brackets of the second source detection bracket (710) and the third source detection bracket (720) are located above the first lanthanum bromide crystal detector (310) and the second lanthanum bromide crystal detector (320) inside the base.

10. The radioactive noble gas detection device according to claim 9, characterized in that: The thickness of the first lead shielding plate (250) is 0.8 mm to 1.2 mm, and the thickness of the second shielding lead plate and the third shielding lead plate (350) are both 9 mm to 11 mm.

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