A method and system for online monitoring of beta and gamma rays in floating nuclear power plants

Abstract

This invention discloses an online monitoring method and system for beta and gamma rays in a floating nuclear power plant, relating to the field of radiation monitoring technology. Based on the range of the radiation source, it monitors radiation signals by designing a reasonable range position. The acquisition space is designed based on the different ranges of beta and gamma ray signals. By utilizing the different ranges of beta and gamma ray signals, gamma ray interference signals are subtracted during the acquisition of beta ray signals, effectively improving monitoring accuracy. The online monitoring system of this solution integrates the detection component into the measuring pipe and connects it to the process pipeline under test. Based on a direct contact measurement method, it effectively acquires low-level beta and gamma ray signals that may exist in the inert gas or liquid in the pipeline. Furthermore, it reduces the interference of gamma rays on beta ray measurements through compensation measurement technology, while simultaneously achieving real-time measurement of gamma rays.

Description

Technical Field

[0001] This invention relates to the field of radiation monitoring technology, specifically to a method and system for online monitoring of beta and gamma rays in floating nuclear power plants. Background Technology

[0002] To determine the effectiveness and normal operation of floating nuclear power plant reactor systems and equipment based on radiation levels, real-time and effective radioactivity monitoring of process fluids within pipelines is required. However, due to the low radioactivity levels, small decay branching ratios, and low characteristic ray energies of inert gases or liquids in some pipelines, the detection efficiency of online pipeside measurements is low, making it difficult to meet the sensitivity requirements for low-level β and γ ray detection. Furthermore, the sampling pipelines in offline sampling monitoring methods introduce complexity and uncertainty. Summary of the Invention

[0003] The technical problem to be solved by this invention is that traditional online tube-side monitoring methods are inefficient, susceptible to interference signals, and difficult to meet the sensitivity requirements for low-level beta and gamma ray detection, while offline sampling monitoring methods bring complexity and uncertainty. This solution provides an online beta and gamma ray monitoring method and system for floating nuclear power plants.

[0004] This invention is achieved through the following technical solution:

[0005] This solution provides a method for online monitoring of beta and gamma rays in floating nuclear power plants, including the following steps:

[0006] Step 1: Simultaneously collect β-ray and γ-ray signals in the first, second, and third spaces of the radiation field of the radiation source: β-ray and γ-ray signals are collected simultaneously in the first space, γ-ray signals are collected in the second space, and γ-ray signals are collected in the third space; the centers of the first, second, and third spaces are arranged sequentially along ray L, which is a perpendicular line to the pipe where the radiation source is located. The first space is closest to the pipe where the radiation source is located and passes through the pipe wall of the pipe where the radiation source is located.

[0007] Step 2: Based on the gamma-ray signal acquired in the second space, subtract the gamma-ray interference signal from the gamma-ray signal acquired in the first space to obtain the gamma-ray dose rate; calculate the gamma-ray dose rate based on the gamma-ray signal acquired in the third space.

[0008] The working principle of this scheme is as follows: Traditional online pipe-side monitoring methods directly collect different radiation signals by setting up acquisition devices next to the pipe. During the acquisition process, other interference signals from the surrounding area can affect the monitoring accuracy and make it difficult to meet the sensitivity requirements for low-level beta and gamma ray detection. This scheme is based on the range of the radiation source and monitors radiation signals by designing reasonable range positions. The acquisition space is designed based on the different ranges of beta and gamma ray signals. By utilizing the different ranges of beta and gamma ray signals, gamma ray interference signals are subtracted during the acquisition of beta ray signals, effectively improving the monitoring accuracy.

[0009] As the radiation from the X-ray source passes through the first, second, and third spaces in sequence, both beta-ray and gamma-ray signals are collected simultaneously in the first space. Since the range of beta-ray radiation is limited, gamma-ray signals are collected in the second space to compensate for the gamma-ray signals collected in the first space to obtain accurate beta-ray radiation signals. When the X-ray source radiates into the third space, only gamma-ray signals remain, and gamma-ray signals can be accurately collected in the third space as well.

[0010] A further optimized scheme is that the β-ray signal and γ-ray signal are scintillation light signals.

[0011] The further optimized solution is that step two includes the following sub-steps:

[0012] S21, the scintillation light signal collected in the first space is photoelectrically converted to obtain pulse signal A1, and the scintillation light signal collected in the second space is photoelectrically converted to obtain pulse signal A2. The pulse signals A1 and A2 are triggered to output TTL pulse signals A1 and A2 with the same duration, respectively.

[0013] S22, Acquire the trigger time T of two sets of TTL pulse signals. A1 and T A2 Using TTL pulse signal A1 as the gate signal, calculate T A1 and T A2 The difference △T;

[0014] S23, if ΔT is less than the threshold T, then subtract TTL pulse signal A2 from TTL pulse signal A1 and then calculate the dose rate of β-rays; otherwise, calculate the dose rate of β-rays directly based on TTL pulse signal A1.

[0015] This solution also provides an online monitoring system for beta and gamma rays in floating nuclear power plants, used to implement the online monitoring method for beta and gamma rays in floating nuclear power plants described above, including:

[0016] The detector assembly is used to simultaneously collect beta-ray and gamma-ray signals in the first, second, and third spaces of the radiation field of the radiation source: wherein beta-ray and gamma-ray signals are collected simultaneously in the first space, gamma-ray signals are collected in the second space, and gamma-ray signals are collected in the third space; the centers of the first, second, and third spaces are arranged sequentially along ray L, which is a perpendicular line of the radiation source flow pipe; the first space is closest to the pipe where the radiation source is located and passes through the pipe wall where the radiation source is located.

[0017] The calculation module is used to obtain the dose rate of beta rays by subtracting gamma ray interference signals from the beta ray signals and gamma ray signals acquired in the first space based on the gamma ray signals acquired in the second space; and to calculate the gamma ray dose rate based on the gamma ray signals acquired in the third space.

[0018] Measuring pipe fittings are similar to flow pipes that carry detector components and serve as radiation sources;

[0019] The shielding component is wrapped around the flow channel where the detector component is located to shield the detector component.

[0020] The measuring tube and shielding assembly form a low-background, high-capacity measuring chamber, improving the detection sensitivity to low-level radioactive media.

[0021] A further optimized solution is that the detector assembly is cylindrical, installed perpendicular to the measuring tube and directly contacts the radiation source through the tube wall; a shielding assembly is wrapped around the detector assembly, and a shielding assembly is also installed on the tube wall that the detector assembly points to through the measuring tube.

[0022] This modular line monitoring system features a compact, integrated design that facilitates installation and disassembly within the shielding assembly. The mechanical positioning of the detector assembly can also be achieved through the connector structure inside the shielding assembly.

[0023] A further optimized solution is that the detector assembly includes: a first high β / γ plastic scintillator detector, a second high β / γ plastic scintillator detector, a high γ plastic scintillator detector, and an insulating material;

[0024] The first β / γ plastic scintillator detector, the second β / γ plastic scintillator detector, and the γ plastic scintillator detector are sequentially assembled into a cylindrical structure. The first β / γ plastic scintillator detector, the second β / γ plastic scintillator detector, and the γ plastic scintillator detector occupy spaces that constitute the first space, the second space, and the third space, respectively. Insulating material is wrapped around the outer surface of the cylindrical structure, and the insulating material corresponding to the first β / γ plastic scintillator detector passes through the tube wall of the measuring tube and directly contacts the radiation source.

[0025] A further optimized solution includes a photoelectric conversion module, with a first high β / γ plastic scintillator detector, a second high β / γ plastic scintillator detector, and a high γ plastic scintillator detector each connected to a photoelectric conversion module.

[0026] A further optimization scheme is that the thickness of the first high β / γ plastic scintillator detector and the second high β / γ plastic scintillator detector are the same, and the thickness of the high γ plastic scintillator detector is greater than that of the first high β / γ plastic scintillator detector.

[0027] A further optimization is that the thickness of the high-γ plastic scintillator detector is at least 50 times the thickness of the first high-β / γ plastic scintillator detector.

[0028] A further optimization is that the shielding component 3 is made of lead alloy, and polyethylene material is filled between the detector component and the shielding component.

[0029] The shielding assembly is made of lead alloy of a certain thickness. Encasing the detector assembly, the shielding assembly has a cylindrical structure, effectively shielding the detector assembly from radiation while ensuring sufficient strength. Simultaneously, high-temperature resistant high-density polyethylene material is filled between the detector assembly and the shielding assembly, and ceramic insulation is used on the top, bottom, and sides of the shielding assembly. The shielding of the measuring tube should completely enclose the extended area of ​​the measuring tube to create a low-background measuring environment and reduce interference from external radiation on the measured object.

[0030] The first β / γ plastic scintillator detector (using a high β / γ thin plastic scintillator detector) at the front end of the detector assembly is sensitive to both β and γ rays. During measurements in β and γ ray radiation fields, this scintillator detector outputs the total number of scintillating photons resulting from the interaction of β and γ rays with the scintillator. The photoelectric conversion module (using a SiPM photoelectric component) performs real-time photoelectric conversion and amplification of the scintillating light. Due to the limited range of β rays, the second β / γ plastic scintillator detector (using a high β / γ thin plastic scintillator detector identical to the first β / γ plastic scintillator detector) will only be sensitive to γ ​​rays, outputting the number of scintillating photons resulting from the interaction of γ rays with the scintillator, thus achieving γ ray compensation for the first high β / γ thin plastic scintillator detector.

[0031] Due to its greater thickness, the high-gamma plastic scintillator detector can effectively attenuate high-energy gamma rays and transmit the generated scintillating light to the photoelectric conversion module, thereby realizing the photoelectric conversion and amplification of high-energy gamma rays.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] This invention provides an online monitoring method for beta and gamma rays in floating nuclear power plants. Based on the range of radiation from the radiation source, the method monitors radiation signals by designing a reasonable range position. The method designs the acquisition space based on the different ranges of beta and gamma ray signals, and uses the different ranges of beta and gamma ray signals to subtract gamma ray interference signals during the acquisition of beta ray signals, effectively improving the monitoring accuracy.

[0034] This invention provides an online monitoring system for beta and gamma rays in floating nuclear power plants. The detection components are integrated into a measuring pipe, which is connected to the process pipeline under test. Based on a direct contact measurement method, it effectively collects low-level beta and gamma ray signals that may be present in the inert gas or liquid within the pipeline. Furthermore, compensation measurement technology reduces the interference of gamma rays on beta ray measurements, while simultaneously enabling real-time gamma ray measurement. On the other hand, this system replaces traditional photomultiplier tubes with photoelectric conversion modules, improving light collection efficiency, enhancing the rigidity and operational stability of the device, and reducing its weight and size, thus meeting the installation space and technical requirements of floating nuclear power plants. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0036] Figure 1 A schematic diagram of the process for online monitoring of beta and gamma rays in floating nuclear power plants;

[0037] Figure 2 A schematic diagram of the structure of an online monitoring system for beta and gamma rays in a floating nuclear power plant;

[0038] Figure 3 This is a schematic diagram of the cross-section of the detector assembly structure;

[0039] Figure 4 This is a schematic diagram illustrating the principle of online monitoring of beta and gamma rays in a floating nuclear power plant.

[0040] In the attached diagram:

[0041] 1-Detector assembly, 11-First high β / γ plastic scintillator detector, 12-Second high β / γ plastic scintillator detector, 13-High γ plastic scintillator detector, 14-Insulating material, 15-Photoelectric conversion module, 16-Signal line centralized processing module, 2-Measuring fitting, 3-Shielding assembly, 4-Connector, 5-Signal line. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0043] To determine the effectiveness and normal operation of floating nuclear power plant reactor systems and equipment based on radiation levels, real-time and effective radioactivity monitoring of process fluids within pipelines is necessary. However, due to the low radioactivity levels, small decay branching ratios, and low characteristic ray energies of inert gases or liquids in some pipelines, the detection efficiency of online pipeside measurements is low, making it difficult to meet the sensitivity requirements for low-level β and γ ray detection. Furthermore, offline sampling monitoring methods introduce complexity and uncertainty into the sampling pipeline. This invention provides the following embodiments to address the above problems:

[0044] Example 1

[0045] This embodiment provides a method for online monitoring of beta and gamma rays in a floating nuclear power plant, such as... Figure 1 As shown, the steps include:

[0046] Step 1: Simultaneously collect β-ray and γ-ray signals in the first, second, and third spaces of the radiation field of the radiation source: β-ray and γ-ray signals are collected simultaneously in the first space, γ-ray signals are collected in the second space, and γ-ray signals are collected in the third space; the centers of the first, second, and third spaces are arranged sequentially along ray L, which is a perpendicular line to the pipe where the radiation source is located. The first space is closest to the pipe where the radiation source is located and passes through the pipe wall of the pipe where the radiation source is located.

[0047] Step 2: Based on the gamma-ray signal acquired in the second space, subtract the gamma-ray interference signal from the gamma-ray signal acquired in the first space to obtain the gamma-ray dose rate; calculate the gamma-ray dose rate based on the gamma-ray signal acquired in the third space.

[0048] The beta-ray and gamma-ray signals are scintillation signals. Step two includes the following sub-steps:

[0049] S21, the scintillation light signal collected in the first space is photoelectrically converted to obtain pulse signal A1, and the scintillation light signal collected in the second space is photoelectrically converted to obtain pulse signal A2. The pulse signals A1 and A2 are triggered to output TTL pulse signals A1 and A2 with the same duration, respectively.

[0050] S22, Acquire the trigger time T of two sets of TTL pulse signals. A1 and T A2Using TTL pulse signal A1 as the gate signal, calculate T A1 and T A2 The difference △T;

[0051] S23, if ΔT is less than the threshold T, then subtract TTL pulse signal A2 from TTL pulse signal A1 and then calculate the dose rate of β-rays; otherwise, calculate the dose rate of β-rays directly based on TTL pulse signal A1.

[0052] In this embodiment, two high β / γ thin plastic scintillators are placed in the first and second spaces, and a high γ thick plastic scintillator is placed in the third space to collect β-ray and γ-ray signals. The scintillating light output by the two high β / γ thin plastic scintillators is converted into a fast pulse signal with a steep rising edge after passing through the SiPM optoelectronic module conversion circuit. In order to extract effective pulse information, the fast pulse is sent to a fast comparator to trigger the formation of a square wave pulse with a threshold of 100mV and a pulse width of 200ns. Then, it is further processed in a TTL pulse generator to generate a +5V TTL pulse A1 and a TTL pulse A2 in the output. The pulse duration is 10μs, and the trigger times of the two sets of pulses are recorded as TA1 and TA2.

[0053] Using the TTL pulse signal A1 of the first β / γ thin plastic scintillator as the gate signal, the difference ΔT between TA1 and TA2 is calculated. If ΔT is less than T = 2 μs, it is considered that the anti-coincidence effect has occurred, that is, the γ-rays have produced scintillation effect on both the first and second β / γ thin plastic scintillator crystals. Therefore, it is necessary to consider subtracting this signal from the total output signal of the first detector to reduce the interference of γ-rays and obtain the dose rate of β-rays.

[0054] For the scintillation light output by the high-gamma-ray thick plastic scintillator, the gamma-ray dose rate is calculated after photoelectric conversion, amplification and TTL forming.

[0055] Example 2

[0056] This embodiment provides an online monitoring system for beta and gamma rays in a floating nuclear power plant, used to implement the online monitoring method for beta and gamma rays in a floating nuclear power plant described in the previous embodiment, such as... Figure 2 As shown, it includes:

[0057] Detector assembly 1 is used to simultaneously collect β-ray and γ-ray signals in the first space, second space and third space of the radiation field of the radiation source: wherein β-ray and γ-ray signals are collected simultaneously in the first space, γ-ray signals are collected in the second space and γ-ray signals are collected in the third space; the centers of the first space, the second space and the third space are arranged sequentially along the ray L, the ray L is a perpendicular line of the radiation source flow pipe, the first space is closest to the pipe where the radiation source is located and the first space passes through the pipe wall of the pipe where the radiation source is located;

[0058] The calculation module is used to obtain the dose rate of beta rays by subtracting gamma ray interference signals from the beta ray signals and gamma ray signals acquired in the first space based on the gamma ray signals acquired in the second space; and to calculate the gamma ray dose rate based on the gamma ray signals acquired in the third space.

[0059] Measuring fitting 2 is the same as the flow pipe that carries the detector assembly and serves as the X-ray source;

[0060] The shielding component 3 is wrapped around the flow pipe where the detector component is located to shield the detector component.

[0061] The detector assembly 1 is cylindrical and is installed perpendicular to the measuring tube 2 and passes through the tube wall of the measuring tube 2 to directly contact the radiation source. The shielding assembly 3 is wrapped around the detector assembly 1, and the shielding assembly 3 is also installed on the tube wall that the detector assembly 1 points to through the measuring tube 2.

[0062] like Figure 3 As shown, the detector assembly 1 includes: a first high β / γ plastic scintillator detector 11, a second high β / γ plastic scintillator detector 12, a high γ plastic scintillator detector 13, and an insulating material 14;

[0063] The first β / γ plastic scintillator detector 11, the second β / γ plastic scintillator detector 12, and the γ plastic scintillator detector 13 are sequentially spliced ​​into a cylindrical structure. The first β / γ plastic scintillator detector 11, the second β / γ plastic scintillator detector 12, and the γ plastic scintillator detector 13 occupy spaces that constitute the first space, the second space, and the third space, respectively. The insulating material 14 is wrapped around the outer surface of the cylindrical structure. The insulating material 14 corresponding to the first β / γ plastic scintillator detector 11 passes through the tube wall of the measuring tube and directly contacts the radiation source.

[0064] It also includes a photoelectric conversion module 15, a first high β / γ plastic scintillator detector 11, a second high β / γ plastic scintillator detector 12, and a high γ plastic scintillator detector 13, each connected to a photoelectric conversion module 15. The signal lines 5 of each photoelectric conversion module 15 are collected together through a signal line centralized processing module 16.

[0065] The first high β / γ plastic scintillator detector 11 and the second high β / γ plastic scintillator detector 12 have the same thickness, and the high γ plastic scintillator detector 13 has a greater thickness than the first high β / γ plastic scintillator detector 11.

[0066] The thickness of the high-γ plastic scintillator detector 13 is at least 50 times the thickness of the first high-β / γ plastic scintillator detector 11.

[0067] like Figure 4 As shown, the processing steps included in the calculation module, i.e., the signal centralized processing unit, are as follows:

[0068] The first high β / γ plastic scintillator detector 11 outputs β and γ scintillation light, which is processed by photoelectric conversion module A1 and outputs a set of pulse signals. The second high β / γ plastic scintillator detector 12 outputs γ scintillation light, which is processed by photoelectric conversion module A2 and outputs a set of pulse signals. The high γ plastic scintillator detector 13 outputs γ scintillation light, which is processed by photoelectric conversion module B and outputs a set of pulse signals. The three sets of pulse signals are respectively processed by rapid prototyping circuit A, rapid prototyping circuit B and rapid prototyping circuit C to output three sets of TTL pulse signals. The first two sets are used to perform γ-ray compensation calculation and output the β-ray dose rate. The last set is used to output the γ-ray dose rate.

[0069] The shielding component 3 is made of lead alloy, and polyethylene material is filled between the detector component 1 and the shielding component 3.

[0070] The online monitoring system for beta and gamma rays in floating nuclear power plants can effectively collect beta and gamma rays generated by the decay of inert gases and liquids in process pipelines. The detector components of this system include two types of plastic detectors: a high-beta / gamma thin plastic scintillator detector, which can reduce the measurement interference of gamma rays in the object under test on beta rays through compensation, and achieve high-efficiency and accurate measurement of beta rays in inert gases; and a high-gamma thick plastic scintillator detector, which deposits all the energy loss of gamma rays inside the detector, generating a large amount of photoelectric effect, and realizing effective monitoring of low and medium energy gamma rays. This system is used for online gamma monitoring of liquids or inert gases in process pipelines to ensure the safe operation of the reactor.

[0071] Example 3

[0072] This embodiment provides a floating nuclear power plant online monitoring device for beta and gamma rays. The detector assembly of this device adopts a modular design, consisting of two... High β / γ thin plastic scintillator detector (including 2 SiPM photoelectric conversion modules), 1 The device consists of a high-gamma-ray thick plastic scintillator detector (including one SiPM photoelectric conversion module) and a centralized signal processing unit. The measuring tube is an extended stainless steel tube, 500mm long, with a diameter of 350mm at both ends and 450mm at the center. This design increases the volume or mass of the object being measured, improving detection efficiency. The device also features a 60mm thick lead shielding layer to reduce background radiation interference. Furthermore, the device is connected to the process pipe via flanges at both ends, resulting in a compact structure and convenient installation and maintenance. Tests have shown that the device can effectively detect beta and gamma rays in inert gases within process pipelines and can perform real-time online analysis of gamma rays in liquids within process pipelines, with an energy response range of 80keV to 2.5MeV. The beta ray measurement range is 10... 6 Bq / m 3 ~3.7×10 15 Bq / m 3 ( 133 The measurement range for Xe and gamma rays is 3.7 × 10⁻⁶. 2 Bq / m 3 ~3.7×10 12 Bq / m 3 ( 137 The device measures 500mm (L) × 450mm (W) × 450mm (H) and weighs 45kg, meeting the process monitoring technical requirements of a floating nuclear power plant reactor radiation monitoring system.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for online monitoring of beta and gamma rays in a floating nuclear power plant, characterized in that, Including the following steps: Step 1: Simultaneously collect β-ray and γ-ray signals in the first, second, and third spaces of the radiation field of the radiation source: β-ray and γ-ray signals are collected simultaneously in the first space, γ-ray signals are collected in the second space, and γ-ray signals are collected in the third space; the centers of the first, second, and third spaces are arranged sequentially along ray L, which is a perpendicular line to the pipe where the radiation source is located. The first space is closest to the pipe where the radiation source is located and passes through the pipe wall of the pipe where the radiation source is located. Step 2: Based on the gamma-ray signal acquired in the second space, subtract the gamma-ray interference signal from the gamma-ray signal acquired in the first space to obtain the dose rate of the gamma-ray; Calculate the gamma-ray dose rate based on gamma-ray signals acquired in the third space; Step two includes the following sub-steps: S21, the scintillation light signal collected in the first space is photoelectrically converted to obtain pulse signal A1, and the scintillation light signal collected in the second space is photoelectrically converted to obtain pulse signal A2. The pulse signals A1 and A2 are triggered to output TTL pulse signals A1 and A2 with the same duration, respectively. S22, Acquire the trigger time T of two sets of TTL pulse signals. A1 and T A2 Using TTL pulse signal A1 as the gate signal, calculate T A1 and T A2 The difference △T; S23, if ΔT is less than the threshold T, then subtract TTL pulse signal A2 from TTL pulse signal A1 and then calculate the dose rate of β-rays; otherwise, calculate the dose rate of β-rays directly based on TTL pulse signal A1.

2. The method for online monitoring of beta and gamma rays in a floating nuclear power plant according to claim 1, characterized in that, The beta-ray and gamma-ray signals are scintillation signals.

3. A floating nuclear power plant online monitoring system for beta and gamma rays, characterized in that, The method for online monitoring of beta and gamma rays in a floating nuclear power plant as described in claim 1 or 2 includes: Detector assembly 1 is used to simultaneously collect β-ray and γ-ray signals in the first space, second space and third space of the radiation field of the radiation source: wherein β-ray and γ-ray signals are collected simultaneously in the first space, γ-ray signals are collected in the second space and γ-ray signals are collected in the third space; the centers of the first space, the second space and the third space are arranged sequentially along the ray L, the ray L is a perpendicular line of the radiation source flow pipe, the first space is closest to the pipe where the radiation source is located and the first space passes through the pipe wall of the pipe where the radiation source is located; The calculation module is used to obtain the dose rate of beta rays by subtracting gamma ray interference signals from the beta ray signals and gamma ray signals acquired in the first space based on the gamma ray signals acquired in the second space; and to calculate the gamma ray dose rate based on the gamma ray signals acquired in the third space. Measuring fitting 2 is the same as the flow pipe that carries the detector assembly and serves as the X-ray source; Shielding component 3 is wrapped around the flow pipe where the detector component is located to shield the detector component; The detector assembly 1 includes: a first high β / γ plastic scintillator detector 11, a second high β / γ plastic scintillator detector 12, a high γ plastic scintillator detector 13, and an insulating material 14; The first β / γ plastic scintillator detector 11, the second β / γ plastic scintillator detector 12, and the γ plastic scintillator detector 13 are sequentially spliced ​​and arranged into a cylindrical structure. The first β / γ plastic scintillator detector 11, the second β / γ plastic scintillator detector 12, and the γ plastic scintillator detector 13 occupy spaces that constitute the first space, the second space, and the third space, respectively. The insulating material 14 is wrapped around the outer surface of the cylindrical structure. The insulating material 14 corresponding to the first β / γ plastic scintillator detector 11 passes through the tube wall of the measuring tube and directly contacts the radiation source. It also includes a photoelectric conversion module 15, a first high β / γ plastic scintillator detector 11, a second high β / γ plastic scintillator detector 12, and a high γ plastic scintillator detector 13, each connected to a photoelectric conversion module 15.

4. The floating nuclear power plant beta-ray and gamma-ray online monitoring system according to claim 3, characterized in that, The detector assembly 1 is cylindrical in shape. The detector assembly 1 is installed perpendicular to the measuring tube 2 and passes through the tube wall of the measuring tube 2 to directly contact the radiation source. The shielding assembly 3 is wrapped around the detector assembly 1, and the shielding assembly 3 is also installed on the tube wall that the detector assembly 1 points to through the measuring tube 2.

5. The floating nuclear power plant beta-ray and gamma-ray online monitoring system according to claim 4, characterized in that, The first high β / γ plastic scintillator detector 11 and the second high β / γ plastic scintillator detector 12 have the same thickness, and the high γ plastic scintillator detector 13 has a greater thickness than the first high β / γ plastic scintillator detector 11.

6. The floating nuclear power plant beta-ray and gamma-ray online monitoring system according to claim 5, characterized in that, The thickness of the high-γ plastic scintillator detector 13 is at least 50 times the thickness of the first high-β / γ plastic scintillator detector 11.

7. The floating nuclear power plant beta-ray and gamma-ray online monitoring system according to claim 4, characterized in that, The shielding component 3 is made of lead alloy, and polyethylene material is filled between the detector component 1 and the shielding component 3.

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