A neutron flux measurement interference cancellation system and method

Abstract

The present application relates to the technical field of neutron flux measurement, and particularly relates to a neutron flux measurement interference elimination system and method, which comprises: a detection unit for detecting neutron flux and sending an initial measurement signal; a reference signal generation unit for generating a reference signal; a transmission unit for transmitting the initial measurement signal, the initial measurement signal being interfered to form an interfered measurement signal during transmission; and a processing unit for receiving the interfered measurement signal and the reference signal, and obtaining the initial measurement signal according to the reference signal and the interfered measurement signal. The present application collects the interference signal during transmission of the measurement signal as the reference signal or generates the reference signal by simulating the known interference signal, and then eliminates the interfered measurement signal based on the offset algorithm, so as to restore the real and accurate neutron flux measurement signal.

Description

Technical Field

[0001] This invention relates to the technical field of neutron flux measurement, and specifically to a neutron flux measurement interference cancellation system and method. Background Technology

[0002] Neutron flux measurement interference cancellation systems are used for core power monitoring and radiation dose monitoring, and are widely used in nuclear facilities such as nuclear power plants and test reactors. Neutron flux signals are generally quite weak; for example, the range of a neutron flux measurement instrument in a pressurized water reactor nuclear power plant is 10... -11 A~10 -3 A. Weak current systems have always been significantly affected by interference during the construction and operation of nuclear power plants. During neutron flux measurement, due to the weak neutron signal and the distance between the signal processing unit and the detector, the neutron flux signal is highly susceptible to interference during transmission. Current methods to avoid or eliminate interference primarily employ shielding techniques, such as using multi-layered shielded coaxial cables (including specialized connectors) to prevent signal interference during transmission; or placing the cable away from interference sources during cable installation to avoid interference.

[0003] This technical solution places extremely high demands on the cables and their arrangement. In engineering practice, due to space constraints, the cables cannot be completely kept away from interference sources during cable installation. Interference events frequently occur during neutron channel measurements due to changes in the interference source or environment, affecting the accuracy of neutron flux measurements and potentially leading to reactor trips. Summary of the Invention

[0004] The purpose of this invention is to provide a neutron flux measurement interference cancellation system and method that can eliminate interference during transmission and obtain accurate measurement signals.

[0005] To achieve the above and other related objectives, the present invention provides a neutron flux measurement interference cancellation system, comprising:

[0006] The detection unit is used to detect the neutron flux and send an initial measurement signal;

[0007] Reference signal generation unit, used to generate reference signal;

[0008] A transmission unit is used to transmit the initial measurement signal, which is subjected to interference during transmission to form an interference-affected measurement signal.

[0009] The processing unit is configured to receive the interference-post measurement signal and the reference signal, and obtain the initial measurement signal based on the reference signal and the interference-post measurement signal.

[0010] In one embodiment of the present invention, the reference signal generation unit includes:

[0011] A synchronous accompanying cable is used to collect interference encountered during the transmission of the initial measurement signal and to generate the reference signal.

[0012] In one embodiment of the present invention, the reference signal generation unit further includes a synchronization guarantee device, which is used to ensure that the synchronization accompanying cable and the transmission unit are in the same electromagnetic field.

[0013] In one embodiment of the present invention, the reference signal generation unit includes a reference signal simulation device for simulating the reference signal based on a known interference signal.

[0014] In one embodiment of the present invention, the processing unit performs interference cancellation on the interference-affected measurement signal based on the reference signal and a cancellation algorithm to obtain the initial measurement signal.

[0015] To achieve the above and other related objectives, the present invention also provides a method for eliminating interference in neutron flux measurement, comprising:

[0016] Acquire the signal after interference measurement and the reference signal;

[0017] The initial measurement signal is obtained by performing a cancellation algorithm on the interference measurement signal based on the reference signal.

[0018] In one embodiment of the present invention, the step of obtaining the measurement signal after interference includes:

[0019] The neutron flux is detected by a probe, and the initial measurement signal is generated.

[0020] The initial measurement signal is transmitted via a signal transmission cable. During transmission, the initial measurement signal is interfered with, resulting in the interfered measurement signal.

[0021] In one embodiment of the present invention, the step of obtaining the reference signal includes:

[0022] The synchronous accompanying cable collects the interference and generates the reference signal.

[0023] In one embodiment of the present invention, the step of obtaining the reference signal includes:

[0024] Measurement to obtain interference signals;

[0025] The reference signal is generated and output based on the interference signal.

[0026] In one embodiment of the present invention, the step of obtaining the initial measurement signal by performing a cancellation algorithm on the interference measurement signal based on the reference signal includes:

[0027] The reference signal is processed and then inverted to obtain an anti-interference signal that is opposite to the reference signal.

[0028] The interference-affected measurement signal is processed and then subjected to a synchronization adjustment algorithm to obtain the interference verification signal;

[0029] The initial measurement signal is obtained by superimposing the anti-interference signal and the interference detection signal.

[0030] The technical advantage of this invention lies in its ability to collect interference signals during the transmission of the initial measurement signal as a reference signal, or to generate a reference signal by simulating known interference signals. Then, based on a cancellation algorithm, the interference-affected measurement signal is eliminated, thereby restoring a true and accurate neutron flux measurement signal. This invention avoids signal disturbances caused by interference sources exceeding strength limits or unexpected changes in the electromagnetic environment of the cable installation location, where interference cannot be filtered out. It also effectively filters out both occasional and difficult-to-filter interference. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the neutron flux measurement interference cancellation system provided in a specific embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a neutron flux measurement interference cancellation system provided in a specific embodiment of the present invention;

[0033] Figure 3 This is another schematic diagram of the neutron flux measurement interference cancellation system provided in a specific embodiment of the present invention;

[0034] Figure 4 This is a flowchart illustrating the neutron flux measurement interference cancellation method provided in a specific embodiment of the present invention. Detailed Implementation

[0035] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] Neutron flux refers to the number of neutrons passing through a unit area per unit time, and it is a crucial indicator for evaluating a nuclear reactor. Neutron flux distribution measurement is extremely important for the safe operation of the reactor, fuel management, determination of the maximum permissible power, the conduct of various experiments, and sample irradiation. During neutron flux measurement, due to the weak neutron signal and the long distance between the signal processing unit and the detector, the neutron flux signal is highly susceptible to interference during transmission. Currently, the main method to avoid or eliminate interference is shielding technology. However, this technology places extremely high demands on the cables and their arrangement. In engineering practice, due to space constraints, the inability to keep the cables completely away from interference sources, changes in interference sources, or environmental changes, interference events frequently occur during neutron channel measurement, affecting the accuracy of neutron flux measurement and potentially leading to reactor tripping. Therefore, this invention proposes a neutron flux measurement interference cancellation system and method to solve the above problems.

[0037] Please see Figures 1 to 4 , Figure 1 This is a schematic diagram of the neutron flux measurement interference cancellation system provided in a specific embodiment of the present invention. Figure 2 This is a schematic diagram of the specific structure of the neutron flux measurement interference cancellation system provided in a specific embodiment of the present invention. Figure 3 This is another structural schematic diagram of the neutron flux measurement interference cancellation system provided in a specific embodiment of the present invention. Figure 4 This is a schematic flowchart of a neutron flux measurement interference cancellation method provided in a specific embodiment of the present invention. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the type, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0038] Combination Figure 1 , Figure 2 and Figure 3 A neutron flux measurement interference cancellation system is shown, comprising: a detection unit 100 for detecting neutron flux and sending an initial measurement signal; a reference signal generation unit 200 for generating a reference signal; a transmission unit 300 for transmitting the initial measurement signal, wherein the initial measurement signal is interfered with during transmission to form an interfered measurement signal; and a processing unit 400 for receiving the interfered measurement signal and the reference signal, and obtaining the initial measurement signal based on the reference signal and the interfered measurement signal.

[0039] This invention introduces a reference signal generation unit 200 to generate a reference signal consistent with the interference signal received by the initial measurement signal. The processing unit 400 then uses this reference signal to eliminate interference in the interfered measurement signal, restoring it to the original measurement signal and obtaining the true neutron flux measurement signal. The detection unit 100 includes a probe 110 and a connecting plate 120. The probe 110 directly detects leaking neutrons in the reactor, responds to the neutron flux, and emits an initial measurement signal. The connecting plate 120 connects the signal transmission cable in the transmission unit 300 and transmits the initial measurement signal to the processing unit 400 via the signal transmission cable. Figure 2 or Figure 3 The transfer process in the transfer unit 300 also includes a reactor containment vessel 500 and a penetration member 510. When a nuclear power plant reactor accident occurs, a large amount of radioactive material is released. The containment vessel 500, as the last nuclear safety barrier, prevents the spread of radioactive material and contamination of the surrounding environment. It also often serves as the enclosure structure of the reactor building, protecting the reactor equipment system from adverse external influences. It is a large, specialized container structure. The penetration member 510 ensures the boundary sealing of cables passing through the containment vessel 500. Under normal or various accident conditions, including earthquakes and loss-of-coolant accidents, the penetration member 510 ensures the integrity of the reactor containment vessel 500, prevents the leakage of radioactive material, and maintains the continuity of electrical and signal systems inside and outside the containment vessel 500.

[0040] In one embodiment, the reference signal generation unit 200 includes: a synchronous accompanying cable 210, used to collect interference encountered during the transmission of the initial measurement signal and generate the reference signal.

[0041] In one embodiment, the reference signal generation unit 200 further includes a synchronization guarantee device 220, which is used to ensure that the synchronization accompanying cable 210 and the transmission unit 300 are in the same electromagnetic field.

[0042] Specifically, in combination Figure 2The schematic diagram shown is of an embodiment of a neutron flux measurement interference cancellation system. The reference signal generation unit 200 can be configured to include a synchronization cable 210 and a synchronization guarantee device 220. The synchronization cable 210 is positioned in the same electromagnetic field as the transmission unit 300, used to collect the interference signal received by the initial measurement signal in the transmission unit 300 and generate a reference signal. The synchronization guarantee device 220 ensures that the synchronization cable 210 and the transmission unit 300 are in the same electromagnetic field, so that the reference signal experiences the same interference as the initial measurement signal. The application of the synchronization cable 210 can avoid signal disturbances caused by interference sources exceeding strength limits or changes in the electromagnetic environment of the cable's location, where interference cannot be filtered out. In practical applications, the synchronization cable 210 and the signal transmission cable 300 can use the same cable material, and the synchronization guarantee device 220 is a device that can fix the synchronization cable 210 and the signal transmission cable 300 together.

[0043] In one embodiment, the reference signal generation unit 200 includes a reference signal simulation device for simulating the reference signal based on a known interference signal.

[0044] Specifically, such as Figure 3 The schematic diagram of another embodiment of the neutron flux measurement interference cancellation system shown illustrates that, by measuring the interference in the transmission unit 300 on-site, if the interference signal is stable and can be simulated, the reference signal generation unit 200 can also be configured as a reference signal simulation device. This device simulates the interference signal received by the initial measurement signal during the transmission process in the transmission unit 300, generates a reference signal, and outputs it. The reference signal simulation device must ensure that the generated reference signal is completely consistent with the pace and amplitude of the interference signal.

[0045] In one embodiment, the processing unit 400 performs interference cancellation on the interference-affected measurement signal based on the reference signal and a cancellation algorithm to obtain the initial measurement signal.

[0046] Specifically, the reference signal is generated by collecting interference through the synchronization cable 210 or by simulating interference signals through a reference signal simulation device. Therefore, the reference signal is subject to the same interference as the initial measurement signal. The processing unit 400 conditions and amplifies the reference signal, passes it through an analog-to-digital converter, and then performs an inversion calculation to obtain an anti-interference signal that is completely opposite to the interference signal. The interference-affected measurement signal is then subjected to the same conditioning and amplification as the reference signal, passed through an analog-to-digital converter, and then processed by a synchronization adjustment algorithm to obtain the interference verification signal. The anti-interference signal and the interference verification signal are then superimposed to obtain the digital signal of the initial measurement signal after noise interference is eliminated. The synchronization adjustment algorithm is an algorithm that adjusts the timing of the anti-interference signal and the interference verification signal to make them synchronized, thereby ensuring the accuracy of the superposition calculation of the two digital signals.

[0047] The following will combine Figure 4 The neutron flux measurement interference cancellation method provided by this invention will be described in detail.

[0048] Step S1: Acquire the measured signal and reference signal after interference.

[0049] In one embodiment, the step of acquiring the measurement signal after interference includes:

[0050] The neutron flux is detected by probe 110, and the initial measurement signal is generated.

[0051] The initial measurement signal is transmitted via a signal transmission cable. During transmission, the initial measurement signal is interfered with, resulting in the interfered measurement signal.

[0052] Specifically, this method uses the above-mentioned neutron flux measurement interference cancellation system to measure the neutron flux through the probe 110 of the detection unit 100 to obtain an initial measurement signal, which is then transmitted through the signal transmission cable of the transmission unit 300. During the transmission process, the initial measurement signal is affected by noise and other interferences, resulting in an interference measurement signal.

[0053] In one embodiment, the step of acquiring the reference signal includes:

[0054] The synchronous accompanying cable collects the interference and generates the reference signal.

[0055] Specifically, applications Figure 2In the embodiment of the neutron flux measurement interference cancellation system shown, the reference signal is acquired through the synchronous accompanying cable 210 and subjected to the same interference as the initial measurement signal during transmission. The reference signal is generated and output. The synchronization guarantee device 220 of the reference signal generation unit 200 ensures that the synchronous accompanying cable 210 and the transmission unit 300 are in the same electromagnetic field, so that the reference signal and the initial measurement signal are subjected to the same interference during transmission. That is, the frequency and amplitude of the interference signals received by the reference signal and the initial measurement signal are completely consistent.

[0056] In one embodiment, the step of acquiring the reference signal includes:

[0057] Measurement to obtain interference signals;

[0058] The reference signal is generated and output based on the interference signal.

[0059] Specifically, applications Figure 3 In another embodiment of the neutron flux measurement interference cancellation system shown, the acquisition of the reference signal requires on-site measurement to determine that the interference signal is stable and can be simulated. A reference signal simulation device can then be set up to generate and output the reference signal based on the measured interference signal. The reference signal acquired in this embodiment is also consistent with the interference experienced by the initial measurement signal during transmission. The reference signal simulation device in this embodiment can be internally integrated into the processing unit 400.

[0060] Step S2: Apply a cancellation algorithm to the interference-affected measurement signal based on the reference signal to obtain the initial measurement signal.

[0061] In one embodiment, the step of obtaining the initial measurement signal by performing a cancellation algorithm on the interference-affected measurement signal based on the reference signal includes:

[0062] The reference signal is processed and then inverted to obtain an anti-interference signal that is opposite to the reference signal.

[0063] The interference-affected measurement signal is processed and then subjected to a synchronization adjustment algorithm to obtain the core measurement signal;

[0064] The initial measurement signal is obtained by superimposing the anti-interference signal and the nuclear test signal.

[0065] Specifically, after the processing unit 400 receives the interference-induced measurement signal and the reference signal, in order to eliminate the interference in the interference-induced measurement signal and obtain the initial measurement signal, the reference signal needs to be conditioned and amplified, then converted into a digital signal by an analog-to-digital converter circuit, and then inverted to obtain an anti-interference signal that is completely opposite to the interference signal. In addition, the interference-induced measurement signal is also conditioned and amplified, converted into a digital signal by an analog-to-digital converter circuit, and then synchronized with the anti-interference signal by a synchronization adjustment algorithm to obtain the verification signal. The two digital signals, the anti-interference signal and the verification signal, are superimposed to obtain the digital signal of the initial measurement signal after interference elimination.

[0066] It should be noted that the steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they contain the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0067] This invention utilizes the principle of field superposition. By introducing a reference signal generation unit, a reference signal consistent with the interference signal encountered during the transmission of the initial measurement signal is generated. Then, a cancellation algorithm is used to interact the reference signal with the interfered measurement signal to eliminate the interference, achieving noise reduction and obtaining a true neutron flux measurement signal. Embodiments of this invention propose setting up a synchronous accompanying cable under the same electromagnetic field as the transmission unit to collect interference from the transmission unit and form a reference signal; alternatively, interference signals from the transmission unit can be obtained through on-site measurement, and when they are stable and simulable, the interference signal is simulated and output as a reference signal. This invention avoids signal disturbances caused by interference sources exceeding intensity limits or unexpected changes in the electromagnetic environment of the cable installation location, where interference cannot be filtered out. It also effectively filters out both occasional and difficult-to-filter interference.

[0068] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A neutron flux measurement interference cancellation system, characterized in that, include: The detection unit is used to detect the neutron flux and send an initial measurement signal; Reference signal generation unit, used to generate reference signal; A transmission unit is used to transmit the initial measurement signal, which is subjected to interference during transmission to form an interference-affected measurement signal. A processing unit is configured to receive the interference-triggered measurement signal and the reference signal, and obtain the initial measurement signal based on the reference signal and the interference-triggered measurement signal, wherein the processing unit performs interference cancellation on the interference-triggered measurement signal based on the reference signal using a cancellation algorithm to obtain the initial measurement signal; The reference signal generation unit includes a synchronization cable and a synchronization guarantee device. The synchronization cable is used to collect the interference encountered during the transmission of the initial measurement signal and generate the reference signal. The synchronization guarantee device is used to ensure that the synchronization cable and the transmission unit are in the same electromagnetic field.

2. The neutron flux measurement interference cancellation system according to claim 1, characterized in that, The reference signal generation unit includes a reference signal simulation device, used to simulate the reference signal based on known interference signals.

3. A method for eliminating neutron flux measurement interference using the neutron flux measurement interference elimination system according to any one of claims 1 to 2, characterized in that, include: Acquire the measured signal and reference signal after interference; The initial measurement signal is obtained by performing a cancellation algorithm on the interference-affected measurement signal based on the reference signal.

4. The neutron flux measurement interference cancellation method according to claim 3, characterized in that, The steps for obtaining the measured signal after interference include: The neutron flux is detected by a probe, and the initial measurement signal is generated. The initial measurement signal is transmitted via a signal transmission cable. During transmission, the initial measurement signal is interfered with, resulting in the interfered measurement signal.

5. The neutron flux measurement interference cancellation method according to claim 3, characterized in that, The steps for obtaining the reference signal include: The synchronous accompanying cable collects the interference and generates the reference signal.

6. The neutron flux measurement interference cancellation method according to claim 3, characterized in that, The steps for obtaining the reference signal include: Measurement to obtain interference signals; The reference signal is generated and output based on the interference signal.

7. The neutron flux measurement interference cancellation method according to claim 3, characterized in that, The step of obtaining the initial measurement signal by performing a cancellation algorithm on the interference-affected measurement signal based on the reference signal includes: The reference signal is processed and then inverted to obtain an anti-interference signal that is opposite to the reference signal. The interference-affected measurement signal is processed and then subjected to a synchronization adjustment algorithm to obtain the interference verification signal; The initial measurement signal is obtained by superimposing the anti-interference signal and the interference detection signal.

Images