Method and device for protecting reactor core of nuclear reactor
By identifying and filtering out inaccurate data from SPND signal measurement points, the problem of malfunction in the core protection system was solved, and the reliability of the system was improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-03-27
AI Technical Summary
Existing core protection systems may erroneously trigger protection actions when the core power distribution is abnormal, resulting in insufficient system reliability. This is because inaccurate data from SPND signal measurement points is mistakenly identified as abnormal data.
By identifying abnormal data in the SPND signal measurement points, the cause of the abnormality can be determined, and it can be determined whether the data is out of sync. Out of sync data is not used for core protection decisions, thereby avoiding erroneous protection actions.
This improves the reliability of the core protection system, ensuring that core protection decisions are made based solely on valid data, and avoiding erroneous decisions caused by inaccurate data.
Smart Images
Figure CN121748017A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of nuclear power technology, specifically relating to a method and apparatus for core protection of a nuclear reactor. Background Technology
[0002] In nuclear power plants, the core power monitoring system is one of the monitoring systems that ensures the safe operation of nuclear reactors. The self-powered neutron detector (SPND) is a key sensor in the core power monitoring system for monitoring the core power distribution. Specifically, the core power monitoring system determines the core power distribution by measuring the values of the SPND signal measurement points.
[0003] In traditional technologies, core protection systems can make corresponding decisions based on the core power distribution provided by the core power monitoring system. For example, in the event of an abnormal core power distribution, the core protection system will trigger protective actions, such as alarms or even shutdown.
[0004] However, when dealing with situations where the core protection system triggers protection actions, relevant personnel discovered that sometimes, although the core power distribution determined by measurements from the SPND signal points appears abnormal, the actual core power distribution is normal. In other words, even when the actual core power distribution is normal, the core protection system may still erroneously trigger protection actions, rendering the core protection system unreliable. Summary of the Invention
[0005] The purpose of this application is to provide a method and apparatus for core protection of a nuclear reactor, which can improve the reliability of the core protection system.
[0006] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a method for core protection of a nuclear reactor, the method comprising: If there are abnormal SPND signal measurement points in the respective SPND signal measurement points of the power supply neutron detectors of the nuclear reactor, determine the target information of the abnormal SPND signal measurement points; Based on the target information of the abnormal SPND signal measurement point, determine the cause of the abnormality of the abnormal SPND signal measurement point; Based on the cause of the abnormal SPND signal measurement point, determine whether the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point; In the case where the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point, the measured value of the inaccurate SPND signal measurement point is determined as inaccurate data; wherein, the inaccurate data is not used for the core protection system of the nuclear reactor to make core protection decisions.
[0007] Secondly, embodiments of this application provide a core protection device for a nuclear reactor, the core protection device comprising: The first determining module is used to determine the target information of the abnormal SPND signal measurement point when there is an abnormal SPND signal measurement point in each of the SPND signal measurement points of the respective powered neutron detectors of the nuclear reactor. The second determining module is used to determine the cause of the abnormality of the abnormal SPND signal measurement point based on the target information of the abnormal SPND signal measurement point. The third determining module is used to determine whether the abnormal SPND signal measuring point is an inaccurate SPND signal measuring point based on the cause of the abnormality of the abnormal SPND signal measuring point. The fourth determining module is used to determine the measured value of the inaccurate SPND signal measuring point as inaccurate data when the abnormal SPND signal measuring point is an inaccurate SPND signal measuring point; wherein the inaccurate data is not used for the core protection system of the nuclear reactor to make core protection decisions.
[0008] Thirdly, embodiments of this application provide a computer device including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the method described in the first aspect.
[0009] Fourthly, embodiments of this application provide a computer-readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect.
[0010] Fifthly, embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in the first aspect.
[0011] In this embodiment, when an abnormal SPND signal measuring point exists among the SPND signal measuring points of the nuclear reactor—that is, when the measured value of the SPND signal measuring point is abnormal—the abnormal measured value is not directly used by the nuclear reactor core protection system to make a core protection decision. Instead, the abnormal measured value is further identified. This further identification refers to determining the cause of the abnormality through the target information of the abnormal SPND signal measuring point, and then determining whether the abnormal SPND signal measuring point is a misaligned SPND signal measuring point. The measured value of a misaligned SPND signal measuring point is inaccurate data. When the abnormal measured value is inaccurate data, it is not used by the nuclear reactor core protection system to make a core protection decision. Based on this, when it is accurately identified that the abnormal measurement value is caused by the misalignment of the SPND signal measurement point, the misaligned data will no longer be used by the reactor core protection system to make core protection decisions. This avoids the core protection system from making incorrect core protection decisions using the core power distribution corresponding to the misaligned data, enabling the core protection system to make correct core protection decisions based only on the core power distribution corresponding to the valid data, thereby improving the reliability of the core protection system. Attached Figure Description
[0012] Figure 1 This is a schematic flowchart of a method for protecting the core of a nuclear reactor provided in some embodiments of this application; Figure 2 This is another schematic flowchart of a method for protecting the core of a nuclear reactor provided in some embodiments of this application; Figure 3 This is a structural block diagram of a core protection device for a nuclear reactor provided in some embodiments of this application; Figure 4 These are internal structural diagrams of a computer device provided in some embodiments of this application. Detailed Implementation
[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0014] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0015] The core protection method for nuclear reactors provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.
[0016] For ease of understanding, the following explains the technical terms that may be involved in the embodiments of this application: SPND (Special Spatial Nucleus Discharge Device) is a key device for measuring neutron fluence within the reactor core. It consists of several probes and signal transmission lines. Its basic working principle is as follows: neutrons react nuclearly with the emitter material in the detector, producing charged particles (such as beta particles), which then form a measurable current signal within the detector. The magnitude of this current is proportional to the neutron fluence, which is used to depict the power distribution within the reactor core.
[0017] Core power monitoring system: It is a dedicated computer monitoring and protection system that measures, calculates, displays and records the three-dimensional power distribution within the core of a nuclear reactor in real time and continuously, and assesses the core status and provides over-limit alarms accordingly.
[0018] Core protection system: also known as reactor protection system, is a dedicated safety system based on multiple, independent and redundant sensors and logic circuits that continuously monitors key safety parameters of the reactor and automatically triggers emergency shutdown or other safety measures when these parameters exceed safety limits, in order to protect the integrity of the reactor core and prevent the release of radioactive materials.
[0019] Measurement point: In a monitoring or control system, a measurement point is a unique identifier and location unit defined for a specific sensor probe at a specific physical location. For example, in a core power monitoring system, a measurement point (SPND) is a unique identifier and location unit defined for a probe at a specific physical location within the core. These specific physical locations are several physical locations in the three-dimensional space corresponding to the core. The core power monitoring system uses measurements provided by probes deployed at these physical locations to monitor the three-dimensional power distribution within the core.
[0020] Anomaly: An unacceptable deviation from the measured value acquired by the SPND and its reference true value (standard value) has occurred, exceeding the allowable range.
[0021] It should be noted that, as mentioned in the background section, when dealing with situations where the core protection system triggers protection actions, relevant personnel have found that sometimes, although the core power distribution determined by the measurements from the SPND signal points appears abnormal, the actual core power distribution is actually normal. In other words, even when the actual core power distribution is normal, the core protection system may still erroneously trigger protection actions, leading to unreliability of the core protection system.
[0022] It is known that the core protection system triggers its protection action based on the core power monitoring system detecting anomalies in the core power distribution. Since the core power distribution can be depicted by the measured values from the SPND signal measurement points, the fundamental reason the core power monitoring system can detect anomalies in the core power distribution is the presence of abnormal measured values. In other words, under normal core operation, the measured values collected by the SPND should be normal, but in reality, there are abnormal measured values (denoted as outliers). This indicates that there is inaccurate data in the measured values collected by the SPND.
[0023] It should be noted that the difference between outliers and inaccurate data is that outliers can be either "true" or "false" data, while inaccurate data is always "false" data. "True" data refers to data from SPND signal measurement points during abnormal core operation, while "false" data refers to data from SPND signal measurement points during normal core operation.
[0024] The inaccuracy in the data may be caused by a faulty probe at the SPND signal measurement point. Since the probe is located inside the reactor core for extended periods, it is subject to factors such as radiation, erosion, and high temperatures, which can lead to inaccuracies. Alternatively, the inaccuracy could also be caused by a fault in the signal transmission line.
[0025] In summary, the unreliability of the core protection system's decisions stems from inaccurate data. To improve the reliability of the core protection system, it must trigger protection actions only when they are warranted and not trigger them when they are not. In other words, if outliers or inaccurate data exist in the measurements collected by the SPND (SPND system), the system needs to be able to accurately identify these outliers. Only then can the core protection system make reliable decisions based solely on valid data, avoiding unreliable decisions based on inaccurate data.
[0026] Based on this, in an exemplary embodiment, this application proposes a core protection method for a nuclear reactor. It should be noted that when outliers and inaccurate data exist in the measurements collected by the SPND, the identification action of accurately identifying the outliers as inaccurate data can be performed by the core power monitoring system, the core protection system, or a new hardware and software system. That is, the steps of this method can be performed by the core power monitoring system, the core protection system, or a new hardware and software system; this application does not specifically limit the scope of the method.
[0027] Reference Figure 1 The method includes steps 102-108. Wherein: Step 102: If there are abnormal SPND signal measurement points in the SPND signal measurement points of the respective power supply neutron detectors of the nuclear reactor, determine the target information of the abnormal SPND signal measurement points.
[0028] Among them, abnormal SPND signal measurement points refer to SPND signal measurement points with abnormal measured values. The measured values are also called actual measured values, which refer to current or neutron fluence.
[0029] Under normal core operation, the core power distribution conforms to physical laws, and the measured values, based on the relationship between power and measurement values, also conform to these physical laws. Specifically, the core power distribution along the axial direction approximates a cosine curve, with the highest power in the middle and gradually decreasing to zero towards both ends; its radial distribution approximates a Bessel function, with the highest power in the center and gradually decreasing to zero towards the edges. Therefore, based on these physical laws, the measured value of the SPND signal at a certain moment can be predicted, thus obtaining the predicted value.
[0030] In cases of core physical anomalies or probe malfunctions, the core power distribution no longer conforms to physical laws; that is, the core power distribution exhibits phenomena that are not governed by physical laws. In other words, the measured values at this time show phenomena that are not governed by physical laws and are considered abnormal values.
[0031] It is understandable that during core operation, measurements are taken using probes to obtain more accurate and reliable results and to monitor for any abnormalities.
[0032] Outliers can be obtained in various ways, including but not limited to: being determined by measured and predicted values, or being provided by other systems in the nuclear reactor.
[0033] The target information includes: the initial quantity, location coordinates, and the line number of the signal transmission line to which it belongs. The location coordinates are three-dimensional spatial coordinates, and the SPND signal measurement points may also have measurement point numbers, used to uniquely identify all signal measurement points of the SPND.
[0034] It should be noted that the location of each SPND signal measurement point is designed before the probe is installed. In other words, the coordinate information of the location of each SPND signal measurement point is known. Correspondingly, the signal transmission line through which the data collected by each probe is transmitted is determined when the probe and signal transmission line are set up, and there are relevant records. For example, a mapping table is maintained, which records the mapping relationship between SPND signal measurement points and signal transmission lines.
[0035] Step 104: Determine the cause of the abnormality of the abnormal SPND signal measurement point based on the target information of the abnormal SPND signal measurement point.
[0036] The causes of the anomaly include, but are not limited to: signal transmission line faults, probe faults, and abnormal core operation. For example, based on the aforementioned first quantity, it can be determined whether the cause of the anomaly is a probe fault located at the position corresponding to the abnormal SPND signal measurement point.
[0037] Step 106: Based on the cause of the abnormal SPND signal measurement point, determine whether the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point.
[0038] Taking the causes of the anomaly as signal transmission line failure, probe failure at the location corresponding to the abnormal SPND signal measurement point, or abnormal core operation as examples, in the case of signal transmission line failure, the abnormal SPND signal measurement point is determined to be an inaccurate SPND signal measurement point; in the case of probe failure at the location corresponding to the abnormal SPND signal measurement point, the abnormal SPND signal measurement point is determined to be an inaccurate SPND signal measurement point; in the case of abnormal core operation, the abnormal SPND signal measurement point is determined to be a valid SPND signal measurement point (its measured value is valid data).
[0039] Step 108: In the case that the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point, the measured value of the inaccurate SPND signal measurement point is determined as inaccurate data; wherein, the inaccurate data is not used for the reactor core protection system to make core protection decisions.
[0040] In this embodiment, when an abnormal SPND signal measurement point exists among the SPND signal measurement points of the nuclear reactor, i.e., when the measured value of the SPND signal measurement point is abnormal, the abnormal measured value is not directly used by the nuclear reactor core protection system to make a core protection decision. Instead, the abnormal measured value is further identified. This further identification refers to determining the cause of the anomaly through the target information of the abnormal SPND signal measurement point, and then determining whether the abnormal SPND signal measurement point is a misaligned SPND signal measurement point. The measured value of a misaligned SPND signal measurement point is inaccurate data. When the abnormal measured value is inaccurate data, it is not used by the nuclear reactor core protection system to make a core protection decision. Based on this, when it is accurately identified that the abnormal measured value is caused by the misalignment of the SPND signal measurement point, the inaccurate data is no longer used by the nuclear reactor core protection system to make a core protection decision. This avoids the core protection system using the core power distribution corresponding to the inaccurate data to make an incorrect core protection decision, allowing the core protection system to make a correct core protection decision only based on the core power distribution corresponding to the valid data, thereby improving the reliability of the core protection system.
[0041] In some embodiments, whether each SPND signal measurement point is an anomalous SPND signal measurement point can be determined by the measured value and its corresponding predicted value. Specifically, when there are anomalous SPND signal measurement points among the SPND signal measurement points of each powered neutron detector in the nuclear reactor, before determining the target information of the anomalous SPND signal measurement point, the method further includes: determining the predicted value of the target SPND signal measurement point based on the measured value of the SPND signal measurement points in the set of SPND signal measurement points corresponding to the target SPND signal measurement point; wherein, the target SPND signal measurement point is any SPND signal measurement point of the nuclear reactor, and the first geometric distance between the SPND signal measurement points in the set of SPND signal measurement points and the target SPND signal measurement point is less than or equal to a first distance threshold.
[0042] Wherein, geometric distance is the length of the line segment between two points in three-dimensional space, and the first distance threshold is an empirical value.
[0043] Regarding the determination of the predicted value: If the core protection system has a power reconfiguration algorithm that can reconfigure the power of each SPND signal measurement point, the predicted value can be directly provided by the core protection system.
[0044] In addition, the predicted values can also be obtained using symmetrical location data, big data AI algorithms, or three-dimensional field functions.
[0045] Furthermore, for the predicted values obtained by using the three-dimensional field function, in this embodiment, it is necessary to construct a core physical field spatial correlation model based on the three-dimensional field function (denoted as the SPND signal measurement point signal smoothing prediction model).
[0046] It should be noted that, since the power distribution of the reactor core is continuous and exhibits similarity within a small range (e.g., the power is basically the same, or the rate of change of power is basically the same), when determining the predicted value of the target SPND signal measurement point, we can first obtain the influence weight of the measured values of the SPND signal measurement points in the SPND signal measurement point set on the target SPND signal measurement point; then, based on the measured values and influence weights of the SPND signal measurement points in the SPND signal measurement point set, we can determine the predicted value of the target SPND signal measurement point.
[0047] The influence weight is used to characterize the sensitivity of the measured values of SPND signal measurement points in the SPND signal measurement point set to the predicted values of the target SPND signal measurement point. Influence sensitivity refers to the degree of sensitivity to influence, which can be represented based on the distance of each SPND signal measurement point in the three-dimensional space of the reactor core and the power distribution pattern.
[0048] The operation of determining the predicted value of the target SPND signal measurement point can be achieved through the following formula (1).
[0049] (1) in, The measurement point number is The target SPND signal measurement point is at the sampling time. The predicted value at that time; The measurement point number in the SPND signal measurement point set is The measured values of the SPND signal measurement points are relative to the measurement point number. The influence weight of the target SPND signal measurement point; This is the set of SPND signal measurement points; The measurement point number in the SPND signal measurement point set is The SPND signal measurement point at the sampling time is The measured value at that time.
[0050] Furthermore, in order to make the predicted value closer to the measured value, the above operation of determining the predicted value of the target SPND signal measurement point can also consider adding a diffusion term. The diffusion constant in the diffusion term is used to characterize the spatial propagation characteristics of neutron flux, making the signal smoothing prediction model of the SPND signal measurement point closer to the real physical process. Specifically, the operation of determining the predicted value of the target SPND signal measurement point can be achieved by the following formula (2).
[0051] (2) in, The measurement point number is The target SPND signal measurement point is at the sampling time. The predicted value at that time; The measurement point number in the SPND signal measurement point set is The measured values of the SPND signal measurement points are relative to the measurement point number. The influence weight of the target SPND signal measurement point; This is the set of SPND signal measurement points; The measurement point number in the SPND signal measurement point set is The SPND signal measurement point at the sampling time is The measured value at that time; It is the diffusion constant; For the Laplace operator; The measurement point number is The target SPND signal measurement point is at the sampling time. The measured value at that time.
[0052] It should be noted that the diffusion constant is provided by the core protection system.
[0053] The aforementioned influence weights can be determined based on the distance between each SPND signal measurement point in the three-dimensional space of the reactor core and the power distribution pattern; or they can be provided by the reactor core protection system.
[0054] The determination of influence weights based on the distance and power distribution of each SPND signal measurement point in the three-dimensional space of the reactor core specifically includes: obtaining the weight attenuation factor of the measured value of the SPND signal measurement point in the set of SPND signal measurement points relative to the target SPND signal measurement point; and determining the influence weight of the measured value of the SPND signal measurement point in the set of SPND signal measurement points on the target SPND signal measurement point based on the first geometric distance and weight attenuation factor corresponding to the SPND signal measurement point.
[0055] It should be noted that the above process of determining the influence weights can be obtained by calculating the Gaussian function, and the expression of the Gaussian function is shown in formula (3).
[0056] (3) in, The measurement point number is The target SPND signal measurement point and the measurement point number in the SPND signal measurement point set are The first geometric distance between the SPND signal measurement points; This is a bandwidth parameter, also known as the weight decay factor, used to control the influence on the weights. The rate of decay.
[0057] It is understandable that in formula (3), and The distance and power distribution in "based on the distance and power distribution of each SPND signal measurement point in the three-dimensional space of the reactor core" are respectively represented by the distance and power distribution.
[0058] in, It can be calculated using genetic algorithms, particle swarm optimization algorithms, least binary search methods, etc. Specifically, the second historical measurement value or theoretical value of each SPND signal measurement point at several sampling times can be obtained first; then, based on the second historical measurement value or theoretical value, the weight attenuation factor corresponding to each SPND signal measurement point in the set of SPND signal measurement points can be determined.
[0059] The theoretical value refers to the value of the SPND signal measurement point obtained through theoretical analysis.
[0060] by Taking the least bisection method as an example, firstly, we define a... error function For example, the error function is the sum of squared residuals. This function measures the sum of squared residuals when the parameter is... At that time, the difference between the model prediction value calculated by the SPND signal measurement point signal smoothing prediction model and the actual observation data (i.e., the second historical measurement value or theoretical value).
[0061] Secondly, based on prior knowledge, determine The search range is [a, b], for example [0, 10].
[0062] Next, set an acceptable error range. (For example, 0.001), that is, when the length of the search interval is less than When the iteration stops, the iteration stops.
[0063] For each iteration, the iterative operations include: calculating the midpoint of the search interval; calculating the model prediction values of the test points on both sides of the midpoint, thereby comparing the slope or trend of change within the search interval. The test points are generally two very close points near the midpoint, and the error function values of the two test points are calculated respectively; comparing the magnitude of the error function values corresponding to the two test points; and updating the search interval to the side of the test point with the smaller error function value.
[0064] In determining The influence weights can then be calculated using a Gaussian function. The correspondence between the influence weights and the target SPND signal measurement points, as well as the SPND signal measurement points in the set of SPND signal measurement points, is shown in Table 1 below.
[0065] Table 1: Correspondence between influence weights and target SPND signal measurement points, SPND signal measurement points in the set of SPND signal measurement points, etc.
[0066] The above describes an embodiment of determining the predicted value of a target SPND signal measurement point based on the measured values of SPND signal measurement points in the set of SPND signal measurement points corresponding to the target SPND signal measurement point.
[0067] Then, based on the measured and predicted values of the target SPND signal measurement point, it is determined whether the target SPND signal measurement point is an abnormal SPND signal measurement point.
[0068] Based on the measured and predicted values of the target SPND signal measurement point, it can be determined whether the measured value is an abnormal value. If the measured value is an abnormal value, the target SPND signal measurement point can be determined to be an abnormal SPND signal measurement point. If the measured value is not an abnormal value (i.e., a normal value), the target SPND signal measurement point can be determined to be a normal SPND signal measurement point.
[0069] Furthermore, when determining whether a measured value is an outlier, it is based on the difference between the measured value and the predicted value (i.e., the residual).
[0070] In some embodiments, the determination of whether a measured value is an outlier can be made by a trend check, that is, observing whether the difference between the predicted value and the measured value undergoes a significant step. In other words, it is determined whether the residual undergoes a significant step. If the change in the residual over time is greater than or equal to a preset change threshold, a significant step is determined to have occurred, and the measured value is an outlier; if the change in the residual over time is less than the preset change threshold, no significant step is determined to have occurred, and the measured value is normal. The preset change threshold can be set as needed, and this embodiment does not limit it.
[0071] In some embodiments, the determination of whether a measured value is an outlier can be made by using dynamic residuals, which are calculated based on the residuals.
[0072] In this embodiment, determining whether a target SPND signal measurement point is an abnormal SPND signal measurement point based on its measured and predicted values includes: acquiring a first historical measurement value of the target SPND signal measurement point; wherein, the first historical measurement value is the current sampling time and values prior to that time. The sampled value corresponding to each sampling time. The value is a positive integer; the standard deviation of the first historical measurement value is determined; the dynamic residual is determined based on the measured value, predicted value, and standard deviation of the target SPND signal measurement point; and the target SPND signal measurement point is determined as an abnormal SPND signal measurement point based on the dynamic residual and the preset residual threshold.
[0073] The dynamic residual can be calculated using formula (4).
[0074] (4) in, Time interval Internal test point number is The standard deviation of the first historical measurements of the target SPND signal measurement point; The measurement point number is The target SPND signal measurement point is at the sampling time. The predicted value at that time; The measurement point number is The target SPND signal measurement point is at the sampling time. The measured value at that time. Among them, The endpoints are the sampling times. With sampling time , The number of sampling times, determined by And the sampling interval is determined. Generally, It can be determined based on the operating experience of nuclear power units, and can be modified according to different reactor types, for example. It lasts for 30 minutes.
[0075] It is understood that when the dynamic residual is greater than or equal to a preset residual threshold, the target SPND signal measurement point can be determined as an abnormal SPND signal measurement point; when the dynamic residual is less than the preset residual threshold, the target SPND signal measurement point can be determined as a non-abnormal SPND signal measurement point, i.e., a normal SPND signal measurement point. The preset residual threshold can be set as needed, and this embodiment does not impose any limitations on it.
[0076] In some embodiments, because the SPND signal (i.e., the current signal) is very weak, it is easily affected by external interference (such as fluid vibration), which can cause fluctuations in the measured value. In this case, if the measured value of the target SPND signal measuring point is determined to be an abnormal value due to external interference, i.e., the target SPND signal measuring point is determined to be an abnormal SPND signal measuring point, and then the target information of the abnormal SPND signal measuring point is determined to determine whether it is an inaccurate SPND signal measuring point, it will lead to misjudgment.
[0077] To avoid misjudgments and improve the accuracy of determining whether an abnormal SPND signal measurement point is a misaligned SPND signal measurement point, thereby improving the reliability of the core protection system, this embodiment uses... Further judgment is made based on data from each sampling time. Specifically, if there are abnormal SPND signal measurement points among the SPND signal measurement points of the respective power neutron detectors in the nuclear reactor, the target information of the abnormal SPND signal measurement point is determined, including: if the target SPND signal measurement point is an abnormal SPND signal measurement point, continuing to acquire the target SPND signal measurement point after the current sampling time. Each sampling time One dynamic residual; among which... It is a positive integer; if the target SPND signal measurement point corresponds to If all dynamic residuals are greater than the anomaly detection threshold, then the target information of the abnormal SPND signal measurement point is determined. These are experience points.
[0078] Among them, the judgment operation is: the target SPND signal measurement point corresponding to Whether each dynamic residual is greater than the anomaly detection threshold is determined by formula (5).
[0079] (5) The starting time of the sliding window is the sampling time. The end time of the sliding window is the sampling time. Sliding window cover One dynamic residual; The sampling time is Dynamic residuals over time; The threshold for anomaly detection is an empirical value. for The median of the dynamic residuals.
[0080] It should be noted that the target SPND signal measurement point corresponds to... If there is a dynamic residual less than or equal to the anomaly detection threshold among the dynamic residuals, it can be determined that external interference caused the measurement value fluctuation. At this time, the target information of the abnormal SPND signal measurement point is uncertain, and the process ends.
[0081] The above describes an embodiment for determining whether a target SPND signal measurement point is an abnormal SPND signal measurement point, and for determining the target information of an abnormal SPND signal measurement point.
[0082] Based on the above embodiments, in some embodiments, the independence of abnormal SPND signal measurement points is determined, that is, the target information includes a first quantity. The above-mentioned determination of the abnormal cause of abnormal SPND signal measurement points based on the target information of abnormal SPND signal measurement points includes: determining whether the first quantity of abnormal SPND signal measurement points is less than a first preset quantity threshold; if the first quantity is less than the first preset quantity threshold, then the abnormal cause of abnormal SPND signal measurement points is determined to be a probe failure at the location corresponding to the abnormal SPND signal measurement point.
[0083] If the first quantity is greater than or equal to the first preset quantity threshold, the cause of the anomaly can be determined as abnormal operation of the reactor core, or further determined as abnormal operation of the reactor core or a fault in the signal transmission line.
[0084] The first preset quantity threshold can be set as needed, and this embodiment does not limit it. For example, the first preset quantity threshold can be 1, 2, etc.
[0085] Reference Figure 2 To further determine whether the anomaly is caused by abnormal core operation or a signal transmission line fault, it is necessary to determine the line correlation of the abnormal SPND signal measurement points and the location correlation of the abnormal SPND signal measurement points. Specifically, the target information also includes line number and location coordinate information. After determining whether the first number of abnormal SPND signal measurement points is less than a first preset threshold, the method further includes: If the first quantity is greater than or equal to the first preset quantity threshold, then based on the line number in the target information of the target abnormal SPND signal measurement point, it is determined whether all SPND signal measurement points sharing the same signal transmission line with the target abnormal SPND signal measurement point are abnormal SPND signal measurement points; wherein, the target abnormal SPND signal measurement point is any abnormal SPND signal measurement point of the nuclear reactor, and the measured values of all SPND signal measurement points are transmitted through multiple signal transmission lines, and the signal transmission lines have corresponding line numbers.
[0086] If all SPND signal measurement points sharing the same signal transmission line are abnormal SPND signal measurement points, then the cause of the abnormality of the abnormal SPND signal measurement points is determined to be a fault in the signal transmission line.
[0087] If all SPND signal measurement points sharing the same signal transmission line are considered abnormal SPND signal measurement points, then the neighboring abnormal SPND signal measurement points are determined based on the position coordinate information in the target information of the abnormal SPND signal measurement points. Among them, the second geometric distance between the neighboring abnormal SPND signal measurement points and the target abnormal SPND signal measurement point is less than or equal to the second distance threshold, and the second geometric distance is determined based on the position coordinate information.
[0088] If the second number of adjacent abnormal SPND signal measurement points is less than the second preset number threshold, then the abnormality of the target abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the target abnormal SPND signal measurement point.
[0089] If the second number of adjacent abnormal SPND signal measurement points is greater than or equal to the second preset number threshold, and the core is operating normally, then the abnormal cause of the target abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the target abnormal SPND signal measurement point.
[0090] The second distance threshold is an empirical value, such as the distance between two SPND signal measurement points. It should be noted that the distance between SPND signal measurement points in the reactor core is generally the same.
[0091] It should be noted that the second preset threshold number is an empirical value. Under normal circumstances, a large number of SPND signal measurement points will not fail simultaneously. A large number of simultaneous abnormal measurement values usually indicate a core physical anomaly. Therefore, the second preset threshold number can be an empirical value, such as 3 or 4.
[0092] It is understandable that when the second number of adjacent abnormal SPND signal measurement points is greater than or equal to a second preset threshold, this condition alone cannot accurately determine the cause of the anomaly. This condition points to either abnormal core operation or probe malfunction. This is because not only can probe malfunction cause a large number of simultaneous abnormal measurements, but abnormal core operation can also cause a large number of simultaneous abnormal measurements. The latter is not caused by a fault in the SPND itself. Therefore, abnormal core operation can cause "false positive" interference in subsequent judgments regarding whether SPND signal measurement points are inaccurate. "False positive" interference refers to misjudging abnormal core operation as a fault in the SPND itself.
[0093] At this point, manual inspection of other instrument parameters (such as valve opening, flow rate, main pump speed, pressure, etc.) is required, along with consultation with the Nuclear Power Plant Operation Manual to determine if the reactor core is operating abnormally. If the reactor core is operating abnormally, the cause of the abnormality is determined to be abnormal reactor core operation; if the reactor core is operating normally, the cause of the abnormality is determined to be probe malfunction.
[0094] Furthermore, after determining the cause of the anomaly, it is determined whether the cause of the anomaly at the abnormal SPND signal measurement point is the target anomaly cause; wherein, the target anomaly cause is a signal transmission line fault or a probe fault located at the position corresponding to the abnormal SPND signal measurement point; if the cause of the anomaly at the abnormal SPND signal measurement point is the target anomaly cause, then the abnormal SPND signal measurement point is determined to be an inaccurate SPND signal measurement point. If the cause of the anomaly at the abnormal SPND signal measurement point is abnormal core operation, then the abnormal SPND signal measurement point is determined to be a valid SPND signal measurement point.
[0095] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.
[0096] Based on the same inventive concept, this application also provides a core protection device for a nuclear reactor to implement the core protection method for the nuclear reactor described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more core protection device embodiments of nuclear reactors provided below can be found in the limitations of the core protection method for nuclear reactors described above, and will not be repeated here.
[0097] In one exemplary embodiment, such as Figure 3 As shown, a core protection device for a nuclear reactor is provided, comprising: a first determining module 100, a second determining module 200, a third determining module 300, and a fourth determining module 400, wherein: The first determining module 100 is used to determine the target information of the abnormal SPND signal measurement point when there is an abnormal SPND signal measurement point in the respective SPND signal measurement points of the power neutron detectors of the nuclear reactor.
[0098] The second determining module 200 is used to determine the cause of the abnormality of the abnormal SPND signal measurement point based on the target information of the abnormal SPND signal measurement point.
[0099] The third determining module 300 is used to determine whether the abnormal SPND signal measuring point is an inaccurate SPND signal measuring point based on the cause of the abnormality of the abnormal SPND signal measuring point.
[0100] The fourth determination module 400 is used to determine the measured value of the inaccurate SPND signal measurement point as inaccurate data when the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point; wherein, the inaccurate data is not used for the reactor core protection system to make core protection decisions.
[0101] In one embodiment, the core protection device for a nuclear reactor further includes: The fifth determining module is used to determine the predicted value of the target SPND signal measuring point based on the measured value of the SPND signal measuring point in the set of SPND signal measuring points corresponding to the target SPND signal measuring point; wherein, the target SPND signal measuring point is any SPND signal measuring point of the nuclear reactor, and the first geometric distance between the SPND signal measuring points in the set of SPND signal measuring points and the target SPND signal measuring point is less than or equal to the first distance threshold.
[0102] The sixth determination module is used to determine whether the target SPND signal measurement point is an abnormal SPND signal measurement point based on the measured value and predicted value of the target SPND signal measurement point.
[0103] In one embodiment, the fifth determining module is specifically used for: Obtain the influence weight of the measured values of SPND signal measurement points in the SPND signal measurement point set on the target SPND signal measurement point.
[0104] Based on the measured values and influence weights of SPND signal measurement points in the SPND signal measurement point set, the predicted value of the target SPND signal measurement point is determined.
[0105] In one embodiment, the fifth determining module is specifically used for: Obtain the weight attenuation factor of the measured value of the SPND signal measurement point in the SPND signal measurement point set relative to the target SPND signal measurement point.
[0106] Based on the first geometric distance and weight attenuation factor corresponding to the SPND signal measurement point, the influence weight of the measured value of the SPND signal measurement point in the set of SPND signal measurement points on the target SPND signal measurement point is determined.
[0107] In one embodiment, the sixth determining module is specifically used for: Obtain the first historical measurement value of the target SPND signal measurement point; wherein, the first historical measurement value is the current sampling time and the values before that time. The sampled value corresponding to each sampling time. It is a positive integer.
[0108] Determine the standard deviation of the first historical measurement.
[0109] The dynamic residual is determined based on the measured value, predicted value, and standard deviation of the target SPND signal measurement point.
[0110] Based on the dynamic residual and the preset residual threshold, determine whether the target SPND signal measurement point is an abnormal SPND signal measurement point.
[0111] In one embodiment, the first determining module 100 is specifically used for: If the target SPND signal measurement point is an abnormal SPND signal measurement point, continue to acquire the target SPND signal measurement point after the current sampling time. Each sampling time One dynamic residual; among which... It is a positive integer.
[0112] If the target SPND signal measurement point corresponds to If all dynamic residuals are greater than the anomaly detection threshold, then the target information of the abnormal SPND signal measurement point is determined.
[0113] In one embodiment, the target information includes a first quantity, and the second determining module 200 is specifically used for: Determine whether the first number of abnormal SPND signal measurement points is less than a first preset number threshold.
[0114] If the first quantity is less than the first preset quantity threshold, then the abnormal cause of the abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the abnormal SPND signal measurement point.
[0115] In one embodiment, the target information further includes the line number and location coordinates, and the second determining module 200 is further configured to: If the first quantity is greater than or equal to the first preset quantity threshold, then based on the line number in the target information of the target abnormal SPND signal measurement point, it is determined whether all SPND signal measurement points sharing the same signal transmission line with the target abnormal SPND signal measurement point are abnormal SPND signal measurement points; wherein, the target abnormal SPND signal measurement point is any abnormal SPND signal measurement point of the nuclear reactor, and the measured values of all SPND signal measurement points are transmitted through multiple signal transmission lines, and the signal transmission lines have corresponding line numbers.
[0116] If all SPND signal measurement points sharing the same signal transmission line are abnormal SPND signal measurement points, then the cause of the abnormality of the abnormal SPND signal measurement points is determined to be a fault in the signal transmission line.
[0117] If all SPND signal measurement points sharing the same signal transmission line are considered abnormal SPND signal measurement points, then the neighboring abnormal SPND signal measurement points are determined based on the position coordinate information in the target information of the abnormal SPND signal measurement points. Among them, the second geometric distance between the neighboring abnormal SPND signal measurement points and the target abnormal SPND signal measurement point is less than or equal to the second distance threshold, and the second geometric distance is determined based on the position coordinate information.
[0118] If the second number of adjacent abnormal SPND signal measurement points is less than the second preset number threshold, then the abnormality of the target abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the target abnormal SPND signal measurement point.
[0119] If the second number of adjacent abnormal SPND signal measurement points is greater than or equal to the second preset number threshold, and the core is operating normally, then the abnormal cause of the target abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the target abnormal SPND signal measurement point.
[0120] In one embodiment, the third determining module 300 is specifically used for: Determine whether the cause of the abnormal SPND signal measurement point is the target cause of the abnormality; where the target cause of the abnormality is a fault in the signal transmission line or a fault in the probe located at the position corresponding to the abnormal SPND signal measurement point.
[0121] If the cause of the abnormal SPND signal measurement point is the same as the cause of the target abnormality, then the abnormal SPND signal measurement point is determined to be an inaccurate SPND signal measurement point.
[0122] The modules in the core protection device of the aforementioned nuclear reactor can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of the processor, or they can be stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.
[0123] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 4As shown, this computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores SPND signal data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a core protection method for a nuclear reactor.
[0124] Those skilled in the art will understand that Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0125] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.
[0126] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.
[0127] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A method for core protection of a nuclear reactor, characterized in that, The method includes: If there are abnormal SPND signal measurement points in the respective SPND signal measurement points of the power supply neutron detectors of the nuclear reactor, determine the target information of the abnormal SPND signal measurement points; Based on the target information of the abnormal SPND signal measurement point, determine the cause of the abnormality of the abnormal SPND signal measurement point; Based on the cause of the abnormal SPND signal measurement point, determine whether the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point; In the case where the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point, the measured value of the inaccurate SPND signal measurement point is determined as inaccurate data; wherein, the inaccurate data is not used for the core protection system of the nuclear reactor to make core protection decisions.
2. The method for core protection of a nuclear reactor according to claim 1, characterized in that, Before determining the target information of the abnormal SPND signal measurement point when an abnormal SPND signal measurement point exists in the respective SPND signal measurement points of the powered neutron detectors in the nuclear reactor, the method further includes: Based on the measured values of SPND signal measurement points in the set of SPND signal measurement points corresponding to the target SPND signal measurement point, the predicted value of the target SPND signal measurement point is determined; wherein, the target SPND signal measurement point is any SPND signal measurement point of the nuclear reactor, and the first geometric distance between the SPND signal measurement points in the set of SPND signal measurement points and the target SPND signal measurement point is less than or equal to a first distance threshold. Based on the measured and predicted values of the target SPND signal measurement point, determine whether the target SPND signal measurement point is an abnormal SPND signal measurement point.
3. The method for core protection of a nuclear reactor according to claim 2, characterized in that, The step of determining the predicted value of the target SPND signal measurement point based on the measured values of SPND signal measurement points in the set of SPND signal measurement points corresponding to the target SPND signal measurement point includes: Obtain the influence weight of the measured values of SPND signal measurement points in the SPND signal measurement point set on the target SPND signal measurement point; Based on the measured values of the SPND signal measurement points in the set of SPND signal measurement points and the influence weights, the predicted value of the target SPND signal measurement point is determined.
4. The method for core protection of a nuclear reactor according to claim 3, characterized in that, The step of obtaining the influence weight of the measured values of SPND signal measurement points in the SPND signal measurement point set on the target SPND signal measurement point includes: Obtain the weighted attenuation factor of the measured value of the SPND signal measurement point in the set of SPND signal measurement points relative to the target SPND signal measurement point; Based on the first geometric distance corresponding to the SPND signal measurement point and the weight attenuation factor, the influence weight of the measured value of the SPND signal measurement point in the set of SPND signal measurement points on the target SPND signal measurement point is determined.
5. The method for core protection of a nuclear reactor according to claim 2, characterized in that, The step of determining whether the target SPND signal measurement point is an abnormal SPND signal measurement point based on the measured value and predicted value of the target SPND signal measurement point includes: Obtain the first historical measurement value of the target SPND signal measurement point; wherein, the first historical measurement value is the current sampling time and the values before that time. The sampled value corresponding to each sampling time, the It is a positive integer; Determine the standard deviation of the first historical measurement; The dynamic residual is determined based on the measured value, predicted value, and standard deviation of the target SPND signal measurement point; Based on the dynamic residual and the preset residual threshold, determine whether the target SPND signal measurement point is an abnormal SPND signal measurement point.
6. The method for core protection of a nuclear reactor according to claim 5, characterized in that, In the case where there are abnormal SPND signal measurement points among the respective SPND signal measurement points of the powered neutron detectors in the nuclear reactor, determining the target information of the abnormal SPND signal measurement points includes: If the target SPND signal measurement point is an abnormal SPND signal measurement point, continue to acquire the target SPND signal measurement point after the current sampling time. Each sampling time A dynamic residual; wherein, the It is a positive integer; If the target SPND signal measurement point corresponds to If all dynamic residuals are greater than the anomaly determination threshold, then the target information of the abnormal SPND signal measurement point is determined.
7. The method for core protection of a nuclear reactor according to any one of claims 1-6, characterized in that, The target information includes a first quantity. Determining the cause of the abnormality of the abnormal SPND signal measurement point based on the target information of the abnormal SPND signal measurement point includes: Determine whether the first number of abnormal SPND signal measurement points is less than a first preset number threshold; If the first quantity is less than the first preset quantity threshold, then the abnormality of the abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the abnormal SPND signal measurement point.
8. The method for core protection of a nuclear reactor according to claim 7, characterized in that, The target information also includes line number and location coordinate information. After determining whether the first number of abnormal SPND signal measurement points is less than a first preset number threshold, the method further includes: If the first quantity is greater than or equal to the first preset quantity threshold, then based on the line number in the target information of the target abnormal SPND signal measurement point, it is determined whether all SPND signal measurement points sharing the same signal transmission line with the target abnormal SPND signal measurement point are abnormal SPND signal measurement points; wherein, the target abnormal SPND signal measurement point is any abnormal SPND signal measurement point of the nuclear reactor, and the measured values of all SPND signal measurement points are transmitted through multiple signal transmission lines, and the signal transmission lines have corresponding line numbers; If all SPND signal measurement points sharing the same signal transmission line are abnormal SPND signal measurement points, then the cause of the abnormality of the abnormal SPND signal measurement points is determined to be a signal transmission line fault. If all SPND signal measurement points sharing the same signal transmission line are considered abnormal SPND signal measurement points, then based on the position coordinate information in the target information of the abnormal SPND signal measurement points, the neighboring abnormal SPND signal measurement points of the target abnormal SPND signal measurement points are determined; wherein, the second geometric distance between the neighboring abnormal SPND signal measurement points and the target abnormal SPND signal measurement point is less than or equal to a second distance threshold, and the second geometric distance is determined based on the position coordinate information; If the second number of adjacent abnormal SPND signal measurement points is less than the second preset number threshold, then the abnormality of the target abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the target abnormal SPND signal measurement point. If the second number of adjacent abnormal SPND signal measurement points is greater than or equal to the second preset number threshold and the core is operating normally, then the abnormal cause of the target abnormal SPND signal measurement point is determined to be a probe failure at the location corresponding to the target abnormal SPND signal measurement point.
9. The method for core protection of a nuclear reactor according to claim 8, characterized in that, The step of determining whether the abnormal SPND signal measurement point is an inaccurate SPND signal measurement point based on the cause of the abnormality includes: Determine whether the cause of the abnormal SPND signal measurement point is the target cause of the abnormality; wherein, the target cause of the abnormality is a signal transmission line fault or a probe fault located at the position corresponding to the abnormal SPND signal measurement point; If the cause of the abnormal SPND signal measurement point is the target abnormal cause, then the abnormal SPND signal measurement point is determined to be an inaccurate SPND signal measurement point.
10. A core protection device for a nuclear reactor, characterized in that, The core protection device of the nuclear reactor includes: The first determining module is used to determine the target information of the abnormal SPND signal measurement point when there is an abnormal SPND signal measurement point in each of the SPND signal measurement points of the respective powered neutron detectors of the nuclear reactor. The second determining module is used to determine the cause of the abnormality of the abnormal SPND signal measurement point based on the target information of the abnormal SPND signal measurement point. The third determining module is used to determine whether the abnormal SPND signal measuring point is an inaccurate SPND signal measuring point based on the cause of the abnormality of the abnormal SPND signal measuring point. The fourth determining module is used to determine the measured value of the inaccurate SPND signal measuring point as inaccurate data when the abnormal SPND signal measuring point is an inaccurate SPND signal measuring point; wherein the inaccurate data is not used for the core protection system of the nuclear reactor to make core protection decisions.