Nuclear criticality detector and detection method

Abstract

The present invention provides a nuclear critical detector and a detection method. The detector includes a probe and a signal processing system. The signal processing system includes a signal conversion module, a data processing module and a communication module which are electrically connected in sequence. The probe detects the gamma rays emitted by the radioactive material and converts them into pulse signals for output. The signal conversion module converts and counts the pulse signals to obtain the pulse count rate corresponding to the gamma rays in the set energy interval. The data processing module calculates the dose rate of the radioactive material corresponding to the pulse count rate according to the relationship between the pulse count rate and the dose rate of the radioactive material stored therein to generate a dose rate communication signal, and transmits the dose rate communication signal through the communication module. The dose rate communication signal generated by the nuclear critical detector can be transmitted through an RS485 bus, and there is no external interference and signal attenuation problem during the transmission process, thereby avoiding the false alarm phenomenon caused by inaccurate measurement data.

Description

Technical Field

[0001] The present invention specifically relates to a nuclear criticality detector and a detection 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 nuclear 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 nuclear criticality monitoring 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 nuclear criticality detector that eliminates the occurrence of false alarms in view of the above-mentioned deficiencies in the prior art, and also provide a nuclear criticality detection method accordingly.

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

[0006] The present invention provides a nuclear criticality detector, comprising: a probe and a signal processing system, wherein the signal processing system comprises a signal conversion module, a data processing module and a communication module, wherein the probe, the signal conversion module, the data processing module and the communication module are electrically connected in sequence.

[0007] The probe is used to detect the gamma rays emitted by radioactive materials and convert them into pulse signals for output.

[0008] The signal conversion module is used to receive the pulse signal output by the probe, convert and count the pulse signal to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and send the pulse counting rate to the data processing module.

[0009] The data processing module includes a dose rate calculation module, which is used to calculate the dose rate of the radioactive material corresponding to the pulse counting rate according to the relationship between the pulse counting rate and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal, and transmit the dose rate communication signal through the communication module.

[0010] Optionally, the signal processing system further comprises an alarm output module, wherein the alarm output module is electrically connected to the data processing module.

[0011] The data processing module also includes a threshold comparison module, which is electrically connected to the dose rate calculation module and is used to determine whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein. When the judgment result is "yes", an alarm switch signal is output, and the alarm switch signal is transmitted through the alarm output module.

[0012] Optionally, the data processing module adopts an FPGA chip, and the communication module is an RS485 communication interface.

[0013] Optionally, the signal conversion module includes a pulse filtering circuit and a pulse counting circuit.

[0014] The pulse filter circuit is connected to the probe and is used to receive the pulse signal output by the probe and filter out the pulse whose pulse width is smaller than the set value.

[0015] The pulse counting circuit is electrically connected to the pulse filtering circuit and the data processing module, and is used for counting the pulse signal processed by the pulse filtering circuit to obtain the number of pulses in a second period, and sending the number of pulses to the data processing module.

[0016] Optionally, the signal processing system further includes a parameter storage module.

[0017] The parameter storage module is electrically connected to the communication module and the data processing module, and is used to receive and store the parameter setting command sent by the remote control system;

[0018] The data processing module is also used to execute the parameter setting command to complete the setting of corresponding parameters, and is also used to send the calculated dose rate to the parameter storage module for storage.

[0019] Optionally, the probe is provided with three, namely, an ionization chamber, a medium-dose GM tube and a low-dose GM tube.

[0020] Optionally, the signal processing system further includes a high voltage detection module, a high voltage switching module and a self-checking control module.

[0021] The high-voltage detection module is electrically connected to the communication module and the ionization chamber, and is used to receive a high-voltage detection command sent by the remote control system, detect the high-voltage signal of the ionization chamber, and send the high-voltage signal to the remote control system through the communication module;

[0022] The high-voltage switching module is electrically connected to the communication module and the ionization chamber, and is used to receive a high-voltage switching command sent by a remote control system and control a high-voltage switch signal of the ionization chamber;

[0023] The input end of the self-test control module is electrically connected to the communication module, and the output end thereof is electrically connected to the ionization chamber, the medium-dose GM tube and the low-dose GM tube respectively, and is used to receive the self-test control command sent by the remote control system, detect the equipment function status of the ionization chamber, the medium-dose GM tube and the low-dose GM tube, and send the equipment function status signal to the remote control system through the communication module.

[0024] The present invention also provides a nuclear criticality detection method, comprising:

[0025] The probe detects the gamma rays emitted by radioactive materials and converts them into pulse signals for output.

[0026] The signal conversion module receives the pulse signal output by the probe, converts and counts it to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and sends the pulse counting rate to the data processing module.

[0027] The dose rate calculation module of the data processing module calculates the dose rate of the radioactive material corresponding to the pulse count rate according to the relationship between the pulse count rate and the dose rate of the radioactive material stored therein to generate a dose rate communication signal, and transmits the dose rate communication signal through the communication module.

[0028] Optionally, it also includes:

[0029] The threshold comparison module of the data processing module determines whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein. When the judgment result is "yes", an alarm switch signal is output and the alarm switch signal is transmitted through the alarm output module.

[0030] Optionally, the signal conversion module further comprises a pulse filtering circuit and a pulse counting circuit.

[0031] The pulse filter circuit receives the pulse signal output by the probe and filters out the pulse whose pulse width is smaller than the set value.

[0032] The pulse counting circuit counts the pulse signal processed by the pulse filtering circuit to obtain the number of pulses in a second period, and sends the number of pulses to the data processing module.

[0033] In the present invention, a signal processing system consisting of a signal conversion module, a data processing module and a communication module is integrated in the detector. The pulse signal detected by the probe passes through a filter plate, counts and calculates in sequence, and the formed dose rate communication signal can be transmitted through an 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

[0034] Figure 1 This is a schematic diagram of the structure of the nuclear criticality detector provided in Example 1 of the present invention.

[0035] In the figure: 1. Probe; 2. Data processing module; 3. Communication module; 4. Switch output module; 5. Pulse filtering circuit; 6. Pulse counting circuit; 7. Parameter storage module; 8. High-voltage detection module; 9. High-voltage switching module; 10. Self-test control module. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The present invention provides a nuclear criticality detector, comprising: a probe and a signal processing system, wherein the signal processing system comprises a signal conversion module, a data processing module and a communication module, wherein the probe, the signal conversion module, the data processing module and the communication module are electrically connected in sequence.

[0041] The probe is used to detect the gamma rays emitted by radioactive materials and convert them into pulse signals for output.

[0042] The signal conversion module is used to receive the pulse signal output by the probe, convert and count the pulse signal to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and send the pulse counting rate to the data processing module.

[0043] The data processing module includes a dose rate calculation module, which is used to calculate the dose rate of the radioactive material corresponding to the pulse counting rate according to the relationship between the pulse counting rate and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal, and transmit the dose rate communication signal through the communication module.

[0044] The present invention also provides a neutron criticality detection method, comprising:

[0045] The probe detects the gamma rays emitted by radioactive materials and converts them into pulse signals for output.

[0046] The signal conversion module receives the pulse signal output by the probe, converts and counts it to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and sends the pulse counting rate to the data processing module.

[0047] The dose rate calculation module of the data processing module calculates the dose rate of the radioactive material corresponding to the pulse count rate according to the relationship between the pulse count rate and the dose rate of the radioactive material stored therein to generate a dose rate communication signal, and transmits the dose rate communication signal through the communication module.

[0048] Embodiment 1:

[0049] like Figure 1 As shown, this embodiment provides a nuclear criticality detector, including: a probe 1 and a signal processing system, the signal processing system includes a signal conversion module, a data processing module 2 and a communication module 3, the probe 1, the signal conversion module, the data processing module 2 and the communication module 3 are electrically connected in sequence,

[0050] The probe 1 is used to detect the gamma rays emitted by radioactive substances and convert them into pulse signals for output.

[0051] The signal conversion module is used to receive the pulse signal output by the probe 1, and convert and count it to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and send the pulse counting rate to the data processing module 2.

[0052] The data processing module 2 includes a dose rate calculation module 21, which is used to calculate the dose rate of the radioactive material corresponding to the pulse counting rate according to the relationship between the pulse counting rate and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal, and transmit the dose rate communication signal through the communication module 3.

[0053] Therefore, by integrating a signal processing system consisting of a signal conversion module, a data processing module 2 and a communication module 3 in the detector, the pulse signal detected by the probe 1 is converted, counted and calculated in turn, and the formed dose rate communication signal can be transmitted through the RS485 bus digital signal, such as being transmitted to a remote control system for dose rate judgment. The transmission distance can reach 1200 meters, and there is no external interference and signal attenuation during the transmission process, thereby avoiding false alarms caused by inaccurate measurement data and ensuring normal production and personnel safety.

[0054] In this embodiment, the signal processing system further includes an alarm output module 4, which is electrically connected to the data processing module 2.

[0055] The data processing module 2 also includes a threshold comparison module 22, which is electrically connected to the dose rate calculation module 21 and is used to determine whether the dose rate of the radioactive substance is greater than or equal to the warning dose rate stored therein. When the judgment result is "yes", an alarm switch signal is output and the alarm switch signal is transmitted through the alarm output module 4.

[0056] Therefore, the alarm switch signal generated by the signal processing system integrated in the nuclear detector can also be transmitted to the remote control system through the RS485 bus digital signal, so that the remote control system can quickly issue an alarm signal without processing data.

[0057] In this embodiment, the data processing module 2 adopts an FPGA chip, and the communication module 3 is an RS485 communication interface.

[0058] In this embodiment, the signal conversion module includes a pulse filtering circuit 5 and a pulse counting circuit 6.

[0059] The pulse filter circuit 5 is connected to the probe 1 and is used to receive the pulse signal output by the probe 1 and filter out the pulses with a pulse width less than a set value.

[0060] The pulse counting circuit 6 is electrically connected to the pulse filtering circuit 5 and the data processing module 2 , and is used to count the pulse signal processed by the pulse filtering circuit 5 in seconds to obtain the number of pulses within the second period, and send the pulse number to the data processing module 2 .

[0061] Specifically, in this embodiment, the pulse filtering circuit 5 filters out pulses with a pulse width less than 200 us.

[0062] In this embodiment, the signal processing system further includes a parameter storage module 7, specifically an EEPROM memory.

[0063] The parameter storage module 7 is electrically connected to the communication module 3 and the data processing module 2, and is used to receive and save the parameter setting command sent by the remote control system;

[0064] The data processing module 2 is further used to execute parameter setting commands to complete the setting of corresponding parameters, and is also used to send the calculated dose rate to the parameter storage module 7 for storage.

[0065] In this embodiment, the probe 1 is provided with three, namely, an ionization chamber, a medium-dose GM tube and a low-dose GM tube.

[0066] Ionization chambers, medium-dose GM tubes, and low-dose GM tubes are all radiation detectors, and the detection accuracy of the detectors is different in different dose ranges.

[0067] In this embodiment, the signal processing system further includes a high voltage detection module 8, a high voltage switching module 9 and a self-checking control module 10.

[0068] The high-voltage detection module 8 is electrically connected to the communication module 3 and the ionization chamber, and is used to receive the high-voltage detection command sent by the remote control system, detect the high-voltage signal of the ionization chamber, and send the high-voltage signal to the remote control system through the communication module 3;

[0069] The high-voltage switching module 9 is electrically connected to the communication module 3 and the ionization chamber, and is used to receive the high-voltage switching command sent by the remote control system and control the high-voltage switch signal of the ionization chamber;

[0070] The input end of the self-test control module 10 is electrically connected to the communication module 3, and the output end thereof is electrically connected to the ionization chamber, the medium-dose GM tube and the low-dose GM tube respectively, for receiving the self-test control command sent by the remote control system, detecting the equipment functional status of the ionization chamber, the medium-dose GM tube and the low-dose GM tube, and sending the equipment functional status signal to the remote control system through the communication module 3.

[0071] In summary, the signal processing system of the nuclear criticality detector in the present invention 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.

[0072] The hardware architecture based on FPGA technology has the following advantages:

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] Embodiment 2:

[0079] This embodiment provides a method for performing nuclear criticality detection using the nuclear detector of Embodiment 1, comprising:

[0080] Probe 1 detects the gamma rays emitted by radioactive substances and converts them into pulse signals for output.

[0081] The signal conversion module receives the pulse signal output by the probe 1, converts and counts it to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and sends the pulse counting rate to the data processing module 2.

[0082] The dose rate calculation module 21 of the data processing module 2 calculates the dose rate of the radioactive material corresponding to the pulse count rate according to the relationship between the pulse count rate and the dose rate of the radioactive material stored therein to generate a dose rate communication signal, and transmits the dose rate communication signal through the communication module 3.

[0083] In this embodiment, it also includes:

[0084] The threshold comparison module 22 of the data processing module 2 determines whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein. When the judgment result is "yes", an alarm switch signal is output and transmitted through the alarm output module 4.

[0085] In this embodiment, the signal conversion module further includes a pulse filtering circuit 5 and a pulse counting circuit 6.

[0086] The pulse filter circuit 5 receives the pulse signal output by the probe 1 and filters out the pulses whose pulse width is less than the set value.

[0087] The pulse counting circuit 6 counts the pulse signal processed by the pulse filtering circuit 5 to obtain the number of pulses in a second period, and sends the number of pulses to the data processing module 2 .

[0088] 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 nuclear criticality detector, characterized in that: include: A probe (1) and a signal processing system, wherein the signal processing system comprises a signal conversion module, a data processing module (2) and a communication module (3), wherein the probe (1), the signal conversion module, the data processing module (2) and the communication module (3) are electrically connected in sequence, The probe (1) is used to detect gamma rays emitted by radioactive substances and convert them into pulse signals for output. The signal conversion module is used to receive the pulse signal output by the probe (1), and perform conversion and counting processing on the pulse signal to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and send the pulse counting rate to the data processing module (2). The data processing module (2) comprises a dose rate calculation module (21), wherein the dose rate calculation module (21) is used to calculate the dose rate of the radioactive material corresponding to the pulse count rate according to the relationship between the pulse count rate and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal, and transmit the dose rate communication signal through the communication module (3); The probe (1) is provided with three parts, namely an ionization chamber, a medium-dose GM tube and a low-dose GM tube; The signal processing system further comprises a high voltage detection module (8), a high voltage switching module (9) and a self-checking control module (10). The high-voltage detection module (8) is electrically connected to the communication module (3) and the ionization chamber, and is used to receive a high-voltage detection command sent by the remote control system, detect the high-voltage signal of the ionization chamber, and send the high-voltage signal to the remote control system through the communication module (3); The high-voltage switching module (9) is electrically connected to the communication module (3) and the ionization chamber, and is used to receive a high-voltage switching command sent by a remote control system and control a high-voltage switch signal of the ionization chamber; The input end of the self-check control module (10) is electrically connected to the communication module (3), and the output end thereof is electrically connected to the ionization chamber, the medium-dose GM tube and the low-dose GM tube respectively, and is used to receive a self-check control command sent by a remote control system, detect the device function status of the ionization chamber, the medium-dose GM tube and the low-dose GM tube, and send the device function status signal to the remote control system through the communication module (3).

2. The nuclear criticality detector according to claim 1, characterized in that: The signal processing system further comprises an alarm output module (4), wherein the alarm output module (4) is electrically connected to the data processing module (2). The data processing module (2) further comprises a threshold comparison module (22), the threshold comparison module (22) being electrically connected to the dose rate calculation module (21) and being used for judging whether the dose rate of the radioactive material is greater than or equal to the warning dose rate stored therein, and outputting an alarm switch signal when the judgment result is "yes", and transmitting the alarm switch signal through the alarm output module (4).

3. The nuclear criticality detector according to claim 1, characterized in that: The data processing module (2) adopts an FPGA chip, and the communication module (3) is an RS485 communication interface.

4. The nuclear criticality detector according to any one of claims 1 to 3, characterized in that: The signal conversion module comprises a pulse filtering circuit (5) and a pulse counting circuit (6), The pulse filtering circuit (5) is connected to the probe (1) and is used to receive the pulse signal output by the probe (1) and filter out pulses with a pulse width less than a set value. The pulse counting circuit (6) is electrically connected to the pulse filtering circuit (5) and the data processing module (2) and is used for counting the pulse signal processed by the pulse filtering circuit (5) to obtain the number of pulses in a second period and send the number of pulses to the data processing module (2).

5. The nuclear criticality detector according to any one of claims 1 to 3, characterized in that: The signal processing system further comprises a parameter storage module (7), The parameter storage module (7) is electrically connected to the communication module (3) and the data processing module (2), and is used to receive and store parameter setting commands sent by the remote control system; The data processing module (2) is also used to execute the parameter setting command to complete the setting of the corresponding parameters, and is also used to send the calculated dose rate to the parameter storage module (7) for storage.

6. A nuclear criticality detection method, characterized in that: Using the nuclear criticality detector according to any one of claims 1 to 5, the method comprises: The probe (1) detects the gamma rays emitted by the radioactive material and converts them into pulse signals for output. The signal conversion module receives the pulse signal output by the probe (1), converts and counts the pulse signal to obtain the pulse counting rate corresponding to the gamma ray in the set energy range, and sends the pulse counting rate to the data processing module (2). The dose rate calculation module (21) of the data processing module (2) calculates the dose rate of the radioactive material corresponding to the pulse count rate according to the relationship between the pulse count rate and the dose rate of the radioactive material stored therein, so as to generate a dose rate communication signal, and transmits the dose rate communication signal through the communication module (3).

7. The nuclear criticality detection method according to claim 6, characterized in that: Also includes: The threshold comparison module (22) of the data processing module (2) determines 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", an alarm switch signal is output, and the alarm switch signal is transmitted through the alarm output module (4).

8. The nuclear criticality detection method according to claim 6 or 7, characterized in that: Also includes: The signal conversion module comprises a pulse filtering circuit (5) and a pulse counting circuit (6), The pulse filter circuit (5) receives the pulse signal output by the probe (1) and filters out pulses with a pulse width smaller than a set value. The pulse counting circuit (6) counts the pulse signal processed by the pulse filtering circuit (5) to obtain the number of pulses in a second period, and sends the number of pulses to the data processing module (2).

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