Neutron criticality monitoring system and method

Abstract

The present invention provides a neutron criticality monitoring system and method, the system includes a control system and a neutron criticality detector, the neutron criticality detector includes a probe and a signal processing system, the probe is used to detect neutrons emitted by radioactive materials and convert them into pulse signals, the signal processing system is used to receive the pulse signals output by the probe, and amplify, identify, count and calculate them to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generate a dose rate communication signal, the control system is used to receive the dose rate communication signals transmitted by multiple neutron criticality detectors, and display them. The dose rate communication signal formed by the detector can be transmitted to the control system through the RS485 bus for timely processing, and there is no external interference and signal attenuation during the transmission process, thereby avoiding the false alarm phenomenon caused by inaccurate measurement data, and ensuring normal production and personnel safety.

Description

Technical Field

[0001] The present invention specifically relates to a neutron criticality monitoring system and method. Background Art

[0002] There is a potential risk of nuclear criticality accidents when handling, applying, storing and transporting fissile materials. Although the probability of an accident is very small, once it occurs, the harm caused is huge. The neutron criticality monitoring alarm system can give an alarm before a criticality accident occurs, record the radiation and change process at the accident site, and analyze the criticality accident process.

[0003] Since the detectors of the neutron criticality monitoring and alarm system are installed in the spent fuel processing site, the pulse signals they detect need to be transmitted over long distances to the alarm system for processing. During the long-distance transmission process, the pulse signals are subject to attenuation, external interference and other factors, which can easily cause inaccurate measurement data and lead to false alarms. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a neutron criticality monitoring system to prevent false alarms from occurring, and also provide a neutron criticality monitoring method accordingly.

[0005] The technical solution adopted to solve the technical problem of the present invention is:

[0006] The present invention provides a neutron criticality monitoring system, including a control system and a neutron criticality detector.

[0007] The neutron criticality detector is provided in plurality, and the neutron criticality detector comprises a probe and a signal processing system.

[0008] The probe is used to detect neutrons emitted by radioactive materials and convert them into pulse signals.

[0009] The signal processing system is electrically connected to the probe, and is used to receive the pulse signal output by the probe, and amplify, identify, count and calculate the pulse signal to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generate a dose rate communication signal.

[0010] The control system is electrically connected to the signal processing systems of multiple neutron criticality detectors, and is used to receive and display dose rate communication signals transmitted by the signal processing systems of multiple neutron criticality detectors, and is also used to issue parameter setting instructions to the signal processing systems of the neutron criticality detectors.

[0011] Optionally, the signal processing system of the neutron criticality detector is further used to determine whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and when the determination result is "yes", a first alarm switch signal is generated.

[0012] The control system is also used to judge the number of received first alarm switch signals, and output a second alarm switch signal when the number of first alarm switch signals is greater than a set value.

[0013] Optionally, the signal processing system includes a signal conversion module, a data processing module and a communication module, and the probe, the signal conversion module, the data processing module and the communication module are electrically connected in sequence.

[0014] The signal conversion module is used to receive the pulse signal output by the probe, and amplify, identify and count it to obtain the pulse count value within the preset upper threshold and lower threshold range, and send the pulse count value to the data processing module.

[0015] The data processing module is used to calculate the dose rate of the radioactive material corresponding to the pulse count value according to the relationship between the pulse count value and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal.

[0016] The communication module is electrically connected to the control system via a bus, and is used to transmit the dose rate communication signal to the control system via the bus.

[0017] Optionally, the data processing module is further used to determine whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and when the determination result is "yes", generate a first alarm switch signal,

[0018] The signal processing system also includes a first switch output module, which is electrically connected to the data processing module and to the control system via a bus, and is used to transmit the first alarm switch signal to the control system via the bus.

[0019] Optionally, the data processing module adopts an FPGA chip, and the communication module is an RS485 communication interface.

[0020] Optionally, the signal conversion module includes a signal amplification circuit and a signal discrimination circuit.

[0021] The signal amplifying circuit is connected to the probe and is used to receive, amplify and shape the pulse signal output by the probe.

[0022] The signal discrimination circuit is electrically connected to the signal amplification circuit and the data processing module, and is used to discriminate the pulse signal processed by the signal amplification circuit to obtain the pulse signal within the preset upper threshold and lower threshold range, and count the pulse signals within the range to obtain the number of pulses within the range, and send the pulse number to the data processing module.

[0023] Optionally, the control system includes a signal switching module, a control processing module, a second switch output module, an operation display module and an alarm device.

[0024] The signal transfer module is electrically connected to the signal processing systems of multiple neutron criticality detectors, and is used to receive the communication signal and the first alarm switch signal transmitted by the neutron criticality detector, and perform level standardization conversion.

[0025] The control processing module is electrically connected to the signal switching module and the operation display module, and is used to receive the communication signal converted by the signal switching module and drive the operation display module to display.

[0026] The second switch output module is electrically connected to the signal adapter module and the alarm device, and is used to judge the number of received first alarm switch signals. When the number of first alarm switch signals is greater than a set value, the second alarm switch signal is output to trigger the alarm device to alarm.

[0027] Optionally, the second switch output module is integrated with an RS485 communication interface and a network port for communication data exchange between the system and the radiation monitoring platform.

[0028] Optionally, the control system further comprises a power supply module, which is electrically connected to the control processing module and is used to convert an external power supply into a power supply voltage required by components in the system;

[0029] The signal processing system also includes a power management module and a high voltage converter,

[0030] The power management module is electrically connected to the data processing module and the high-voltage converter, and is used to transmit the system power supply voltage to the high-voltage converter. The high-voltage converter is used to convert the system power input by the power management module into a DC high voltage used by the probe.

[0031] The present invention also provides a neutron criticality monitoring method, comprising:

[0032] The neutron criticality detector is provided in plurality, and the neutron criticality detector comprises a probe and a signal processing system.

[0033] The probe of the neutron criticality detector detects the neutrons emitted by radioactive materials and converts them into pulse signals.

[0034] The signal processing system of the neutron critical detector receives the pulse signal output by the probe, and amplifies, identifies, counts and calculates it to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generates a dose rate communication signal.

[0035] The control system receives and displays the dose rate communication signals transmitted by the signal processing systems of the multiple neutron criticality detectors, and also sends parameter setting instructions to the signal processing systems of the neutron criticality detectors.

[0036] Optionally, it also includes:

[0037] The signal processing system of the neutron critical detector determines whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and generates a first alarm switch signal when the judgment result is "yes".

[0038] The control system determines the number of received first alarm switch signals, and outputs a second alarm switch signal when the number of first alarm switch signals is greater than a set value.

[0039] In the present invention, by integrating a signal processing system in the detector, the pulse signal detected by the probe is amplified, identified, counted and calculated in sequence by the signal processing system, and the formed dose rate communication signal can be transmitted to the control system for timely processing via the RS485 bus digital signal. The transmission distance can reach 1200 meters, and there is no external interference and signal attenuation problem during the transmission process, thereby avoiding false alarms caused by inaccurate measurement data and ensuring normal production and personnel safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the structure of a neutron criticality monitoring system provided in Example 1 of the present invention;

[0041] Figure 2 The schematic diagram of the structure of the neutron criticality detector provided in Example 1 of the present invention. In the figure: 1. Neutron criticality detector; 11. Probe; 12. Data processing module; 13. Communication module; 14. First switch output module; 15. Signal amplification circuit; 16. Signal identification circuit; 17. Power management module; 18. High voltage converter; 2. Control system; 21. Signal transfer module; 22. Control processing module; 23. Second switch output module; 24. Operation display module; 25. Alarm device; 26. Power module. DETAILED DESCRIPTION

[0042] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0043] In the description of the present invention, it should be noted that the directions or positional relationships indicated by “upper” and the like are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0044] In the description of the present invention, the terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The present invention provides a neutron criticality monitoring system, including a control system and a neutron criticality detector.

[0047] The neutron criticality detector is provided in plurality, and the neutron criticality detector comprises a probe and a signal processing system.

[0048] The probe is used to detect neutrons emitted by radioactive materials and convert them into pulse signals.

[0049] The signal processing system is electrically connected to the probe, and is used to receive the pulse signal output by the probe, and amplify, identify, count and calculate the pulse signal to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generate a dose rate communication signal.

[0050] The control system is electrically connected to the signal processing systems of multiple neutron criticality detectors, and is used to receive and display dose rate communication signals transmitted by the signal processing systems of multiple neutron criticality detectors, and is also used to issue parameter setting instructions to the signal processing systems of the neutron criticality detectors.

[0051] The present invention also provides a neutron criticality monitoring method, comprising:

[0052] The neutron criticality detector is provided in plurality, and the neutron criticality detector comprises a probe and a signal processing system.

[0053] The probe of the neutron criticality detector detects the neutrons emitted by radioactive materials and converts them into pulse signals.

[0054] The signal processing system of the neutron critical detector receives the pulse signal output by the probe, and amplifies, identifies, counts and calculates it to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generates a dose rate communication signal.

[0055] The control system receives and displays the dose rate communication signals transmitted by the signal processing systems of the multiple neutron criticality detectors, and also sends parameter setting instructions to the signal processing systems of the neutron criticality detectors.

[0056] Embodiment 1:

[0057] like Figure 1 As shown, this embodiment provides a neutron criticality monitoring system, including a control system 2 and a neutron criticality detector 1.

[0058] There are multiple neutron criticality detectors 1, and the neutron criticality detector 1 includes a probe 11 and a signal processing system.

[0059] The probe 11 is used to detect neutrons emitted by radioactive materials and convert them into pulse signals.

[0060] The signal processing system is electrically connected to the probe 11, and is used to receive the pulse signal output by the probe 11, and amplify, identify, count and calculate it to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generate a dose rate communication signal.

[0061] The control system 2 is electrically connected to the signal processing systems of multiple neutron criticality detectors 1, and is used to receive and display dose rate communication signals transmitted by the signal processing systems of multiple neutron criticality detectors 1, and is also used to issue parameter setting instructions to the signal processing systems of the neutron criticality detectors 1.

[0062] Therefore, by integrating the signal processing system in the neutron critical detector 1, the pulse signal detected by the probe 11 is amplified, identified, counted and calculated in turn by the signal processing system, and the formed dose rate communication signal can be transmitted to the control system 2 through the RS485 bus digital signal for timely processing. The transmission distance can reach 1200 meters, and there is no external interference and signal attenuation problems during the transmission process, thereby avoiding false alarms caused by inaccurate measurement data and ensuring normal production and personnel safety.

[0063] The neutron criticality detectors 1 are distributed in different places and form a neutron criticality monitoring system with the control system 2, so that the monitoring of criticality accidents can achieve better reliability.

[0064] In this embodiment, the signal processing system of the neutron criticality detector 1 is also used to determine whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and when the judgment result is "yes", a first alarm switch signal is generated.

[0065] The control system 2 is also used to determine the number of received first alarm switch signals, and output a second alarm switch signal when the number of first alarm switch signals is greater than a set value.

[0066] Therefore, the alarm switch signal generated by the signal processing system integrated in the neutron criticality detector 1 can also be transmitted to the control system 2 through the RS485 bus digital signal, so that the control system 2 can quickly issue an alarm signal without processing data.

[0067] Furthermore, the control system 2 performs logical judgment on the alarm signals of the neutron criticality detectors 1 at different positions to avoid the alarm phenomenon caused by the false alarm of individual neutron criticality detectors 1 .

[0068] In this embodiment,

[0069] The signal processing system includes a signal conversion module, a data processing module 12 and a communication module 13. The probe 11, the signal conversion module, the data processing module 12 and the communication module 13 are electrically connected in sequence.

[0070] The signal conversion module is used to receive the pulse signal output by the probe 11, and amplify, identify and count the pulse signal to obtain the pulse count value within the preset upper threshold and lower threshold range, and send the pulse count value to the data processing module 12.

[0071] The data processing module 12 is used to calculate the dose rate of the radioactive material corresponding to the pulse count value according to the relationship between the pulse count value and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal.

[0072] The communication module 13 is electrically connected to the control system 2 via a bus, and is used to transmit the dose rate communication signal to the control system 2 via the bus.

[0073] In this embodiment,

[0074] The data processing module 12 is also used to determine whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and when the determination result is "yes", a first alarm switch signal is generated.

[0075] In addition, the data processing module is also used to receive and parse the instructions for setting parameters of each module sent by the control system through the communication module, and execute the corresponding instructions to complete the setting of the corresponding parameters, and is also used to save the parameters and the calculated dose rate.

[0076] The data processing module stores the received parameters separately locally so that the parameters can be read directly after power-on to avoid repeated reception of parameter instructions.

[0077] The signal processing system also includes a first switch output module 14, which is electrically connected to the data processing module 12 and to the control system 2 via a bus, and is used to transmit the first alarm switch signal to the control system 2 via the bus.

[0078] In this embodiment, the signal conversion module includes a signal amplification circuit 15 and a signal identification circuit 16.

[0079] The signal amplifying circuit 15 is connected to the probe 11 and is used to receive, amplify and shape the pulse signal output by the probe 11.

[0080] The signal identification circuit 16 is electrically connected to the signal amplification circuit 15 and the data processing module 12, and is used to identify the pulse signal processed by the signal amplification circuit 15 to obtain a pulse signal within a preset upper threshold and a lower threshold range, and to count the pulse signals within the range to obtain the number of pulses within the range, and to send the number of pulses to the data processing module 12.

[0081] Specifically, the signal discrimination circuit 16 includes a discriminator and a counting and collecting circuit.

[0082] The discriminator includes an upper discriminator and a lower discriminator, and the input ends of the upper discriminator and the lower discriminator are respectively connected to the output end of the signal amplification circuit 15. The upper discriminator is used to compare each pulse value in the pulse signal with a preset upper threshold value, and output a high-level signal when the pulse value is higher than the upper threshold value, and output a low-level signal when it is lower than or equal to the upper threshold value; the lower discriminator is used to compare each pulse value in the pulse signal with a preset lower threshold value, and output a high-level signal when the pulse value is higher than or equal to the lower threshold value, and output a low-level signal when it is lower than the lower threshold value.

[0083] The counting and collecting circuit includes an XOR gate circuit and a timing counter;

[0084] The input end of the XOR gate circuit is connected to the upper discriminator and the lower discriminator respectively, and the XOR gate circuit is used to perform XOR processing on the outputs of the upper discriminator and the lower discriminator, so as to obtain a digital level signal after discrimination;

[0085] The input end of the timing counter is connected to the output end of the XOR gate circuit, and is used to collect the number of pulses in the corresponding identified digital level signal, and send the count value to the data processing module 12.

[0086] In this embodiment, the data processing module 12 adopts an FPGA chip, and the communication module 13 is an RS485 interface circuit.

[0087] The probe part includes two neutron BF3 proportional counter tubes, and the probe 11 outputs tiny pulses at the millivolt level under normal working conditions. The pulse output by the probe is processed by the signal amplification circuit 15 (specifically a three-stage amplification and integer comparison circuit) to become a TTL level signal, which is sent to the FPGA chip to complete millisecond counting and second counting operations, and converted into the corresponding dose rate according to the formula. The FPGA chip also compares the millisecond counting and dose rate results with the set warning dose rate to obtain the alarm status. The intelligent probe part uses the XC7A100TFGG484-2L industrial-grade FPGA chip of Xilinx Company in the United States as the main controller. A large number of embedded blocks and rich logic resources are integrated on the chip, which has the advantages of high cost performance, low power consumption and small package.

[0088] Therefore, the signal processing system of the neutron criticality detector 1 adopts a hardware architecture based on FPGA technology to realize the main control and communication functions, and the stable operation of the system does not rely on the microprocessor and software.

[0089] The hardware architecture based on FPGA technology has the following advantages:

[0090] Determinism: FPGA chips implement the designed security functions in the form of pure hardware circuits. The execution of hardware circuits is more certain than that of software and operating systems.

[0091] Reliability: FPGA chips based on FLASH and FPGA chips based on anti-fuse technology can effectively resist single-particle upsets caused by random radiation, and therefore have higher reliability than CPU chips.

[0092] Security: FPGA technology provides better protection against malicious network attacks. First, the hardware logic burned into the FPGA chip cannot be modified at will without engineering tools; second, the modification of the hardware logic must be carried out through a special interface, which is generally disconnected when the system is running; finally, the hardware logic adopts encryption measures to make it difficult to reproduce the FPGA logic through reverse engineering.

[0093] Performance: Response time depends not only on logic processing time, but also on signal processing time and communication time. The parallel processing method used by the hardware logic inside the FPGA chip has a faster processing speed than the serial processing method of the software code in the CPU chip. In addition, the processing of input and output signals based on the FPGA smart probe is carried out in parallel, and its execution time is not limited by the data refresh rate in a cyclic or periodic manner. The input and output signals of the device can be processed simultaneously, and when the system scale increases, this parallel processing method does not increase the time required for input and output signals.

[0094] Sustainability and economy: CPU chips are updated faster than FPGA chips, which means that the life of probes based on CPU technology is shorter than that of smart probes based on FPGA technology. As CPU chips are updated, it is difficult to port the existing software code in the original CPU chip to the new generation of CPU chips. On the contrary, FPGA technology makes future system upgrades easier. FPGA logic code and register-level design compiled using hardware description language can be ported to new FPGA chips. New FPGA chips only need to re-synthesize and layout the existing code and design using new software tools, and previous investments in software design can be retained to the greatest extent.

[0095] In this embodiment, the control system 2 includes a signal transfer module 21, a control processing module 22, a second switch output module 23, an operation display module 24 and an alarm device 25.

[0096] The signal transfer module 21 is electrically connected to the signal processing systems of the multiple neutron criticality detectors 1, and is used to receive the communication signal and the first alarm switch signal transmitted by the neutron criticality detector 1, and perform level standardization conversion.

[0097] The control processing module 22 is electrically connected to the signal switching module 21 and the operation display module 24, and is used to receive the communication signal converted by the signal switching module 21 and drive the operation display module 24 to display.

[0098] The second switch output module 23 is electrically connected to the signal adapter module 21 and the alarm device 25, and is used to judge the number of the received first alarm switch signals. When the number of the first alarm switch signals is greater than the set value, the second alarm switch signal is output to trigger the alarm device 25 to alarm.

[0099] In this embodiment, there are three neutron criticality detectors 1, and each neutron criticality detector 1 exchanges data with the signal switching module 21 in simplex mode via two RS485 channels to achieve uploading of measurement data of the neutron criticality detector 1 and receiving and responding to operation instructions.

[0100] In this embodiment,

[0101] The control system 2 further includes a power supply module 26, which is electrically connected to the control processing module 22 and is used to convert an external power supply into a power supply voltage required by components in the system;

[0102] The signal processing system further includes a power management module 17 and a high voltage converter 18.

[0103] The power management module 17 is electrically connected to the data processing module 12 and the high-voltage converter 18, and is used to transmit the system power supply voltage to the high-voltage converter 18. The high-voltage converter 18 is used to convert the system power input by the power management module 17 into a DC high voltage used by the probe 11.

[0104] Specifically, the signal switching module 21 provides +24V DC voltage to the intelligent probe through the cable. The power management module 17 uses the +24V voltage as the input of the high-voltage converter 18, and the high-voltage converter 18 performs voltage conversion and outputs high voltage to power the probe.

[0105] The specific functions of each module in control system 2 are as follows:

[0106] Signal transfer module: The signal transfer module 21 is connected to three independent neutron criticality detectors 1, and receives RS485 signals and alarm switch signals transmitted by the detectors. All signals interacting between the smart probe and the signal transfer module must be processed by electrical optocoupler isolation, which improves the anti-interference performance between modules and realizes the level standardization conversion between modules. At the same time, the signal transfer module 21 provides +24V DC voltage to the smart probe through the cable.

[0107] Control processing module: for the measurement data uploaded by the three-way neutron criticality detector 1, the LCD screen is driven to display the three-channel data results in real time. The control processing module 22 controls the interactive operation between the 4x4 keyboard and the LCD screen, and completes the issuance of various functional instructions and data query. The control processing module 22 is responsible for controlling the hardware communication interface signals of the serial port and the network port of the second switch output module 23, and at the same time completes the control of the LED status indicator on the front panel of the chassis.

[0108] Second switch output module: The second switch output module 23 processes the alarm signal transmitted by the signal transfer module 2 out of 3, and finally outputs the redundant alarm status to the alarm light and whistle group in the form of switch quantity. The output module integrates two RS485 and one network port to communicate data with the radiation monitoring platform.

[0109] Warning light and whistle: The warning light and whistle is an alarm device composed of several red lights, green lights and whistles. The red light sends out a red signal, the green light indicates normal operation, and the whistle sends out a sound signal when an alarm is triggered.

[0110] Power module: The power module 26 converts 220VAC power into a +24 DC voltage used by the equipment, which is used to power the system.

[0111] Operation and display module: The operation and display module 24 mainly includes a keyboard and a liquid crystal display screen. The keyboard is used for data input and interface switching. The display screen is used for displaying graphic data. The operation and display module inputs data through the keyboard, and the data is transmitted to the control processing module through the interface bus.

[0112] In this embodiment, the control system 2 is arranged in a chassis, and a standard NIM chassis is equipped with two sets of control system 2 devices.

[0113] Embodiment 2:

[0114] This embodiment provides a method for neutron criticality monitoring using the system of embodiment 1, including:

[0115] The probe 11 of the neutron criticality detector 1 detects the neutrons emitted by the radioactive material and converts them into pulse signals.

[0116] The signal processing system of the neutron criticality detector 1 receives the pulse signal output by the probe 11, and amplifies, identifies, counts and calculates it to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generates a dose rate communication signal.

[0117] The control system 2 receives dose rate communication signals transmitted by the signal processing systems of the plurality of neutron criticality detectors 1 , displays the signals, and sends parameter setting instructions to the signal processing systems of the neutron criticality detectors 1 .

[0118] In this embodiment, it also includes:

[0119] The signal processing system of the neutron critical detector 1 determines whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and generates a first alarm switch signal when the judgment result is "yes".

[0120] The control system 2 determines the number of received first alarm switch signals, and outputs a second alarm switch signal when the number of first alarm switch signals is greater than a set value.

[0121] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A neutron criticality monitoring system, characterized in that: comprising a control system (2) and a neutron criticality detector (1), The neutron criticality detector (1) is provided in plurality, and the neutron criticality detector (1) comprises a probe (11) and a signal processing system. The probe (11) is used to detect neutrons emitted by radioactive substances and convert them into pulse signals. The signal processing system is electrically connected to the probe (11) and is used to receive the pulse signal output by the probe (11), and to amplify, identify, count and calculate the pulse signal to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and to generate a dose rate communication signal. The control system (2) is electrically connected to the signal processing systems of the plurality of neutron criticality detectors (1), and is used to receive and display dose rate communication signals transmitted by the signal processing systems of the plurality of neutron criticality detectors (1), and is also used to send parameter setting instructions to the signal processing systems of the neutron criticality detectors (1); The signal processing system of the neutron criticality detector (1) is also used to judge whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and when the judgment result is "yes", a first alarm switch signal is generated. The control system (2) is also used to judge the number of received first alarm switch signals, and output a second alarm switch signal when the number of first alarm switch signals is greater than a set value.

2. The neutron criticality monitoring system according to claim 1, characterized in that: The signal processing system comprises a signal conversion module, a data processing module (12) and a communication module (13), wherein the probe (11), the signal conversion module, the data processing module (12) and the communication module (13) are electrically connected in sequence. The signal conversion module is used to receive the pulse signal output by the probe (11), and amplify, identify and count the pulse signal to obtain the pulse count value within the preset upper threshold and lower threshold range, and send the pulse count value to the data processing module (12). The data processing module (12) is used to calculate the dose rate of the radioactive material corresponding to the pulse count value according to the relationship between the pulse count value and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal. The communication module (13) is electrically connected to the control system (2) via a bus, and is used to transmit the dose rate communication signal to the control system (2) via the bus.

3. The neutron criticality monitoring system according to claim 2, characterized in that: The data processing module (12) is also used to determine whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and when the determination result is "yes", generate a first alarm switch signal, The signal processing system further comprises a first switch output module (14), the first switch output module (14) being electrically connected to the data processing module (12) and electrically connected to the control system (2) via a bus, and being used for transmitting a first alarm switch signal to the control system (2) via the bus.

4. The neutron criticality monitoring system according to claim 2, characterized in that: The data processing module (12) adopts an FPGA chip, and the communication module (13) is an RS485 communication interface.

5. The neutron criticality monitoring system according to claim 2, characterized in that: The signal conversion module comprises a signal amplification circuit (15) and a signal discrimination circuit (16). The signal amplifying circuit (15) is connected to the probe (11) and is used to receive, amplify and shape the pulse signal output by the probe (11). The signal identification circuit (16) is electrically connected to the signal amplification circuit (15) and the data processing module (12), and is used to identify the pulse signal processed by the signal amplification circuit (15) to obtain the pulse signal within the range of a preset upper threshold and a preset lower threshold, and to count the pulse signals within the range to obtain the number of pulses within the range, and to send the number of pulses to the data processing module (12).

6. The neutron criticality monitoring system according to any one of claims 1 to 5, characterized in that: The control system (2) comprises a signal switching module (21), a control processing module (22), a second switch value output module (23), an operation display module (24) and an alarm device (25). The signal transfer module (21) is electrically connected to the signal processing systems of the plurality of neutron criticality detectors (1), and is used to receive the communication signal and the first alarm switch signal transmitted by the neutron criticality detector (1), and perform level standardization conversion. The control processing module (22) is electrically connected to the signal switching module (21) and the operation display module (24), and is used to receive the communication signal converted by the signal switching module (21), and drive the operation display module (24) to display. The second switch quantity output module (23) is electrically connected to the signal switching module (21) and the alarm device (25) and is used to judge the number of received first alarm switch signals and, when the number of first alarm switch signals is greater than a set value, output a second alarm switch signal to trigger the alarm device (25) to sound an alarm.

7. The neutron criticality monitoring system according to claim 6, characterized in that: The control system (2) further comprises a power supply module (26), the power supply module (26) being electrically connected to the control processing module (22) and being used for converting an external power supply into a power supply voltage required by components in the system; The signal processing system further comprises a power management module (17) and a high voltage converter (18), The power management module (17) is electrically connected to the data processing module (12) and the high-voltage converter (18) and is used to transmit the system power supply voltage to the high-voltage converter (18). The high-voltage converter (18) is used to convert the system power input by the power management module (17) into a DC high voltage used by the probe (11).

8. A neutron criticality monitoring method, characterized in that: include: The neutron criticality detector (1) is provided in plurality, and the neutron criticality detector (1) comprises a probe (11) and a signal processing system. The probe (11) of the neutron criticality detector (1) detects neutrons emitted by radioactive materials and converts them into pulse signals. The signal processing system of the neutron criticality detector (1) receives the pulse signal output by the probe (11), and amplifies, identifies, counts and calculates the pulse signal to obtain the dose rate of the radioactive material corresponding to the neutron in the set energy range, and generates a dose rate communication signal. The control system (2) receives dose rate communication signals transmitted by the signal processing systems of the plurality of neutron criticality detectors (1), displays the signals, and sends parameter setting instructions to the signal processing systems of the neutron criticality detectors (1); The signal processing system of the neutron criticality detector (1) determines whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and generates a first alarm switch signal when the determination result is "yes". The control system (2) determines the number of received first alarm switch signals, and outputs a second alarm switch signal when the number of first alarm switch signals is greater than a set value.

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