Reactivity self-adaptive control method for long-term low-power operation of pressurized water reactor nuclear power unit

Abstract

The application discloses a kind of pressurized water reactor nuclear power unit long-term low-power operation reactivity self-adaptive control method, comprising: real-time extraction core operating state parameter in the first characteristic parameter of characterizing current reactivity change rate, the second characteristic parameter of characterizing the influence trend of xenon poison accumulation and the third characteristic parameter of characterizing power distribution distortion degree;Based on characteristic parameter and current control mode, calculate the reactivity change amount of each time node relative to current time, and compare with preset reactivity safety threshold;If any reactivity change amount is greater than safety threshold, then output target control mode and corresponding control parameter set, send to control system.Through real-time extraction characteristic parameter, predict future reactivity change amount based on current control mode and compare with safety threshold after dynamic output control parameter, improve reactivity control dynamic response ability and precision, solve the problem that it is difficult to adapt to core real-time state change and cannot avoid fuel cladding damage risk in advance.

Description

Technical Field

[0001] This invention relates to the field of nuclear power control technology, and in particular to a reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units. Background Technology

[0002] With the intensive planning and rapid commissioning of new energy projects such as offshore wind power and photovoltaic power generation, the proportion of new energy power generation in regional power grids has increased significantly. The inherent intermittency and volatility of new energy power generation place higher demands on the grid's peak-shaving capacity, causing some grid-connected nuclear power units to frequently participate in grid peak-shaving and operate at low power for extended periods. For large nuclear power units using third-generation pressurized water reactor technology with rated power reaching the megawatt level, their single-unit capacity accounts for a large proportion of the total capacity of the regional power grid, making the contradiction between grid peak-shaving pressure and safe unit operation particularly prominent.

[0003] Prolonged low-power operation and frequent peak shaving of nuclear power units bring a series of safety risks. Among these, the core risk lies in the significantly increased difficulty of reactor core reactivity control. Prolonged low-power operation can lead to xenon toxicity accumulation and uneven burnup distribution, potentially causing localized power peak increases and thus increasing the probability of fuel cladding damage. Furthermore, frequent power fluctuations require reactor control systems with rapid response capabilities, but existing control methods are mostly based on fixed rules or empirical parameters, making them difficult to adapt to complex and changing operating conditions. Therefore, from the perspective of improving the safe and stable operation of nuclear power units, conducting research on the long-term low-power operation and frequent peak shaving control of megawatt-class pressurized water reactor nuclear power units has significant practical implications.

[0004] Currently, China has a certain foundation in the research on the control of long-term low-power operation of pressurized water reactor nuclear power units. For the M310 reactor type, some nuclear power plant operation guidelines stipulate that when the power level is between 50% and 75%, the longest allowed continuous operation period for a single long-term low-power operation is 30 days. Related research institutions have further demonstrated that during long-term low-power operation using boron adjustment, a 75% power platform can operate for 90 days, and a 50% power platform can operate for 50 days; during long-term low-power operation using rod insertion, a 75% power platform can operate for 50 days, and a 20% power platform can operate for 20 days. For 600 MW pressurized water reactor nuclear power units, research has also proposed long-term low-power operation modes that can meet reactor safety requirements.

[0005] However, the aforementioned research findings mainly target the M310 reactor type and 600 MW pressurized water reactor nuclear power units. Their control strategies and operating limits are based on the design characteristics and operational experience of specific reactor types. Different nuclear power units differ significantly from these reactor types in core design, control methods, and safety margins; therefore, existing research findings cannot be applied to all nuclear power units.

[0006] Furthermore, existing control methods mostly rely on static rules or empirical parameters, lacking the ability to dynamically respond to the real-time state of the reactor core. During frequent peak shaving, unit parameters fluctuate significantly, increasing the probability of short-cycle monitoring tests failing. Operator control operations become more frequent, leading to interference between test execution and unit operation, and raising the risk of human error. How to achieve real-time monitoring, dynamic prediction, and adaptive control of reactivity, to identify equipment anomalies in advance, and to reduce the operator's workload, has become a pressing technical problem that needs to be solved for the long-term low-power operation of nuclear power units. Summary of the Invention

[0007] The purpose of this invention is to provide a reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units. By extracting three characteristic parameters in real time—the rate of reactivity change, the trend of xenon poisoning accumulation, and the degree of power distribution distortion—and calculating the future reactivity change based on the current core control mode, comparing it with a preset safety threshold, the method dynamically outputs the target control mode and control parameters. This improves the dynamic response capability and accuracy of reactivity control and solves the problem that existing technologies, which use static rules or empirical parameters, are difficult to adapt to real-time core state changes and cannot avoid the risk of fuel cladding damage in advance.

[0008] To address the aforementioned technical problems, a first aspect of this invention provides a reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit, comprising the following steps: Real-time acquisition of the current operating status parameters of the reactor core, and extraction of a first characteristic parameter to characterize the current rate of reactivity change, a second characteristic parameter to characterize the trend of the influence of xenon poisoning accumulation on reactivity, and a third characteristic parameter to characterize the degree of distortion of the reactor core power distribution from the operating status parameters; Based on the first feature parameter, the second feature parameter, the third feature parameter, and the current core control mode, calculate the change in reactivity of the core reactivity at several time nodes relative to the current time within a preset future time period, and compare the change in reactivity with a preset reactivity safety threshold. If any of the reactivity changes exceeds the reactivity safety threshold, a target control mode and a set of control parameters corresponding to the target control mode are output, and the set of control parameters is sent to the reactor control system for execution.

[0009] Further, the step of outputting a target control mode and a set of control parameters corresponding to the target control mode, and sending the set of control parameters to the reactor control system for execution, includes: Based on the comparison result between the reactivity change amount and the reactivity safety threshold, a target control method is selected from the preset control method library, and the corresponding initial execution rate is calculated based on the target control method and the reactivity change amount. The control operation corresponding to the target control mode is initiated and executed at the initial execution rate, and the actual rate of change of core reactivity is obtained in real time during each sampling period. The actual rate of change is compared with the preset allowable deviation of reactivity rate. If the difference between the actual rate of change and the expected rate of change in the current sampling period exceeds the allowable deviation of the reactive rate of change, the execution rate adjustment amount for the next sampling period is calculated based on the difference and a preset proportional coefficient, and the execution rate for the next sampling period is reduced according to the execution rate adjustment amount.

[0010] Furthermore, the reactive adaptive control method for long-term low-power operation of the pressurized water reactor nuclear power unit also includes: If the difference cannot be recovered to the allowable deviation range of the reactivity change rate within a consecutive preset number of sampling periods, the control operation corresponding to the target control mode is suspended and the core is restored to the current control mode until the actual change rate is less than the preset stable change rate threshold within a consecutive preset number of sampling periods, and then the control operation corresponding to the target control mode is restarted. The stable rate of change threshold refers to the upper limit of the actual rate of change used to determine whether the reactive state has returned to stability.

[0011] Further, the step of calculating the execution rate adjustment amount for the next sampling period based on the difference and a preset proportional coefficient includes: Obtain the current safety margin level of the reactor core, wherein the safety margin level includes a first safety level and a second safety level, and the safety margin of the first safety level is higher than that of the second safety level; Based on the sign of the difference and the safety margin level, the corresponding scaling factor is matched from the preset scaling factor matrix; Based on the proportional coefficient and the difference, the basic adjustment amount is calculated; If the positive or negative sign is a positive sign and the security margin level is the second security level, then the execution rate adjustment amount is calculated in combination with the preset security enhancement coefficient; The security enhancement coefficient is greater than 1.

[0012] Further, the calculation of the corresponding initial execution rate based on the target control method and the reactive change includes: Obtain the control characteristic reference curve corresponding to the target control mode. The control characteristic reference curve pre-calibrates the correspondence between the execution rate and the amount of reactivity change under the reference core state. Obtain the current state parameters of the reactor core, which include at least the current burn-up depth and the current average coolant temperature. Based on the current burnup depth and the current average coolant temperature, calculate the state deviation between the reference core state and the current core state, and determine at least one correction coefficient based on the state deviation. The control characteristic baseline curve is corrected using the correction coefficient to obtain a target control characteristic curve that matches the current core state; Based on the amount of reactive change, the corresponding initial execution rate is determined by linear interpolation on the target control characteristic curve.

[0013] Furthermore, the output of a target control mode and the corresponding set of control parameters includes: Read the mode identification information contained in the target control method, and identify the control mode to which the target control method belongs based on the mode identification information. The control mode includes one of boron adjustment mode, rod insertion mode or hybrid mode. According to the control mode, the corresponding parameter generation rule is retrieved from the preset parameter generation rule library; Based on the reactivity change and the parameter generation rule, calculate the set of control parameters corresponding to the target control method.

[0014] Furthermore, when the target control mode is boron adjustment mode, the calculation of the control parameter set corresponding to the target control mode based on the reactivity change and the parameter generation rule includes: Obtain the xenon toxicity reactivity value and the fuel consumption reactivity value at the current moment; The target compensation reactivity amount is calculated based on the reactivity change, the xenon toxicity reactivity value at the current moment, and the fuel consumption reactivity value at the current moment. Obtain the differential value of boron at the current moment; The change in target boron concentration is calculated based on the total target compensating reactivity and the differential value of boron at the current moment. Based on the target boron concentration change and the preset execution time window, the target boron dilution rate or target boronization rate is calculated, and the target boron dilution rate or target boronization rate is used as the boron adjustment mode parameter in the control parameter set.

[0015] Furthermore, when the target control mode is the plug-in mode, the calculation of the control parameter set corresponding to the target control mode based on the reactive change and the parameter generation rule includes: Obtain the current control rod position distribution in the reactor core and the reactivity value curve for each control rod group; Based on the reactivity change and the reactivity value curve of each control rod group, the target control rod group to be inserted is determined. Obtain the differential reactivity value of the target control rod group at the current rod position; The target rod position change is calculated based on the reactivity change and the differential reactivity value of the target control rod group. Based on the target rod position change and the preset insertion rate constraint, the target insertion rate is calculated and used as the rod insertion mode parameter in the control parameter set.

[0016] Furthermore, when the target control mode is a hybrid mode, the calculation of the control parameter set corresponding to the target control mode based on the reactive change and the parameter generation rule includes: Based on the reactive change and the first characteristic parameter, the initial rod position change and initial insertion rate corresponding to the rod insertion mode are calculated using the rod insertion response function; Initiate and execute the control operation corresponding to the insertion mode, and monitor the actual rate of change of core reactivity and xenon toxicity reactivity value in real time during the execution process; Based on the deviation between the actual rate of change and the expected rate of change, and the changing trend of the xenon toxicity reactivity value, the dynamic boron concentration compensation amount corresponding to the boron adjustment mode is calculated in real time using the boron adjustment compensation function. The dynamic boron concentration compensation is converted into a real-time boron dilution rate or a real-time boronization rate, which, together with the initial rod position change and the initial insertion rate, constitutes a hybrid mode control parameter set.

[0017] Furthermore, the plug response function is expressed as: ; ; in, This represents the initial change in rod position. This is the scaling factor for the insertion rod response. This represents the change in reactivity. The first characteristic parameter, The initial insertion rate, This refers to the response time of the insertion rod. The boron adjustment compensation function is expressed as follows: ; ; ; ; ; in, This is the second deviation between the xenon toxicity reactivity value and the preset expected xenon toxicity reactivity value. This represents the xenon toxicity reactivity value. The preset expected xenon toxicity value, This refers to the reactive bias corresponding to the first deviation between the actual rate of change and the expected rate of change. This represents the actual reactivity value of the reactor core at the current moment. This represents the expected reactivity value at the current moment. The total amount of reactivity that needs to be compensated for in order to adjust boron The preset xenon toxicity compensation coefficient, The preset feedback compensation coefficient, This is the dynamic boron concentration compensation amount. The differential value of boron at the current moment, This refers to the real-time boron dilution rate or real-time boration rate. The preset control cycle; The dynamic boron concentration compensation amount The positive or negative value is used to distinguish the direction of operation: if If it is a positive value, then This is the real-time boron dilution rate; if If it is a negative value, then This represents the real-time boronization rate.

[0018] Accordingly, a second aspect of the present invention provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the above-described reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit.

[0019] Accordingly, a third aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit.

[0020] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects: 1. By extracting three characteristic parameters in real time—the rate of reactivity change, the trend of xenon poison accumulation, and the degree of power distribution distortion—and combining them with the current core control method, dynamic prediction of future reactivity changes and comparison with safety thresholds are achieved. This realizes the transformation from passive response to active prediction, significantly improving the predictability and accuracy of reactivity control, and effectively solving the problem that existing technologies cannot identify the risk of fuel cladding damage in advance due to the use of static rules or empirical parameters. 2. By introducing a real-time feedback adjustment mechanism during the execution of the control parameter set, the deviation between the actual rate of change and the expected rate of change is dynamically monitored and adaptively corrected. When the deviation continues to exceed the standard, the execution is automatically paused and restored to the original control mode to wait for stability. This achieves closed-loop control and safety assurance of the execution process, significantly improves the stability and reliability of the control operation, and effectively reduces the risk of human error caused by parameter fluctuations or execution deviations. 3. By constructing differentiated parameter generation rules for boron adjustment mode, rod insertion mode and hybrid mode, and adopting a real-time coupled control strategy of fast rod insertion response and dynamic boron adjustment compensation in hybrid mode, the advantages of different control methods are complemented and synergistically optimized, which significantly improves the control flexibility and adaptability of the reactor under long-term low-power operation conditions, and effectively solves the contradiction that a single control mode cannot simultaneously meet the requirements of response speed and safety margin. Attached Figure Description

[0021] Figure 1 This is a flowchart of a reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0023] Please refer to Figure 1 The first aspect of this invention provides a reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit, comprising the following steps: Step S100: Real-time acquisition of the current operating status parameters of the reactor core, and extraction of a first characteristic parameter to characterize the current rate of reactivity change, a second characteristic parameter to characterize the trend of xenon poison accumulation on reactivity, and a third characteristic parameter to characterize the degree of distortion of the reactor core power distribution from the operating status parameters.

[0024] The nuclear power plant's distributed control system or core monitoring system collects real-time core operating parameters, including but not limited to neutron flux density, control rod position, coolant boron concentration, coolant temperature, and core power distribution. From these parameters, a first characteristic parameter characterizing the current rate of reactivity change is extracted. This first characteristic parameter reflects the speed of reactivity change per unit time and is a fundamental indicator for assessing dynamic reactivity stability. Simultaneously, a second characteristic parameter characterizing the impact of xenon toxicity accumulation on reactivity is extracted. This second characteristic parameter is calculated based on the core physics model of the generation and decay process of the fission product xenon-135, reflecting the dynamic contribution of xenon toxicity concentration changes to reactivity. A third characteristic parameter characterizing the degree of core power distribution distortion is also extracted. This third characteristic parameter is obtained by calculating the power peak factor or local power gradient using the three-dimensional power distribution reconstructed by in-core detectors, used to identify whether there is uneven power distribution or a trend of local hotspot formation within the core. The combination of these three characteristic parameters enables a multi-dimensional characterization of the core's dynamic reactivity, providing a data foundation for accurate prediction of subsequent reactivity trends.

[0025] Step S200: Based on the first characteristic parameter, the second characteristic parameter, the third characteristic parameter and the current core control mode, calculate the reactivity change of the core reactivity at several time nodes relative to the current time within a preset future time period, and compare the reactivity change with the preset reactivity safety threshold.

[0026] The first, second, and third characteristic parameters obtained in step S100 are used as inputs, and calculations are performed using a core physics model or a pre-constructed reactivity calculation model, combined with the current core control mode. This calculation process uses the measured core reactivity value at the current moment as the initial condition, considering physical effects such as xenon toxicity feedback, burnup feedback, and power distribution feedback, to calculate the change in core reactivity relative to the current moment at several discrete time nodes within a preset future time period. For example, every hour within the next 24 hours can be set as a time node, and the cumulative change in reactivity at each time node relative to the current moment can be calculated. The calculated reactivity changes at each time node are compared one by one with a preset reactivity safety threshold. This preset reactivity safety threshold is the maximum allowable reactivity change determined by back-calculation through thermal-hydraulic analysis and core physics analysis based on safety constraints such as fuel cladding temperature limits and power peak factor limits. Through this comparison process, it is possible to identify whether there are risk moments exceeding the safety threshold within the future time period.

[0027] Step S300: If any of the reactivity changes is greater than the reactivity safety threshold, a target control mode and a set of control parameters corresponding to the target control mode are output, and the set of control parameters is sent to the reactor control system for execution.

[0028] If the comparison result in step S200 shows that the reactivity change at at least one time point exceeds the preset reactivity safety threshold, it is determined that the current control method can no longer meet the safe operation requirements for the future time period, and the control strategy needs to be adjusted. At this time, the system automatically outputs a target control method, which can be one of the following: boron adjustment mode, rod insertion mode, or a hybrid mode. The specific selection depends on the characteristics of the reactivity change and the current core state. Simultaneously, a corresponding set of control parameters is generated based on the target control method. For example, in boron adjustment mode, this includes the target boron dilution rate or target boration rate; in rod insertion mode, it includes the target control rod insertion depth and insertion rate. The generated set of control parameters is sent to the reactor control system for execution, where it is converted into specific adjustment commands. This automatically completes operations such as boron concentration adjustment or control rod movement, achieving timely intervention and adaptive control of core reactivity to ensure that reactivity is always maintained within the safe operating range.

[0029] This invention extracts multi-dimensional parameters that characterize the dynamic features of reactivity in real time, combines them with the current control method to predict future reactivity trends and assess safety, and automatically outputs the target control method and control parameter set to intervene when potential risks are identified. This realizes the transformation from passive response to active prevention, and significantly improves the accuracy and safety of reactivity control of nuclear power units under long-term low-power operation conditions.

[0030] Specifically, step S200, based on the first characteristic parameter, the second characteristic parameter, the third characteristic parameter, and the current core control mode, calculates the change in core reactivity relative to the current time at several time points within a preset future time period, including: Step S210: Based on the current core control mode, retrieve the baseline reactivity prediction model corresponding to the current core control mode from the preset core physics model library. The baseline reactivity prediction model is a pre-established functional relationship or numerical calculation model based on the core physics equations, used to describe the evolution of reactivity over time under a given control mode.

[0031] In the specific implementation of step S210, it is first necessary to establish and maintain a core physics model library. The construction of this model library is completed during the nuclear power unit design phase and the pre-operation preparation phase. Based on the physical design parameters of the nuclear power unit reactor type, by solving the core physics equations, including the point reactor dynamics equations, xenon poisoning dynamics equations, and burnup equations, and combining the calibration data of the control rod differential value curves and boron differential value curves, benchmark reactivity prediction models are established for different control methods. Taking the boron adjustment mode as an example, the core of its benchmark model is the transfer function between boron concentration changes and reactivity changes. The model includes correction factors for boron differential value changes with burnup, the correspondence between xenon poisoning equilibrium concentration and power level, and basic mathematical expressions such as the samarium poisoning accumulation effect. Taking the rod insertion mode as an example, the core of its benchmark model is the correspondence between control rod movement and reactivity changes. The model includes basic data such as the integral value curves and differential value curves of different control rod groups, as well as the coupling coefficient between rod position and power distribution. Taking the hybrid mode as an example, its baseline model is based on the boron adjustment mode and the rod insertion mode, and adds coupling terms that reflect the mutual influence of the two control methods, such as the influence of rod insertion operation on xenon poisoning distribution and the influence of boron adjustment operation on the value of control rods.

[0032] During actual operation, the distributed control system of a nuclear power plant monitors and records the control mode currently used by the reactor core in real time. Control mode identification can be achieved through various means, such as directly reading the current control mode identifier of the control system, or indirectly determining it by analyzing the issuance of control commands. When the control system continuously issues boron concentration adjustment commands but does not issue control rod movement commands, the current control mode can be determined to be boron adjustment mode; when the control system continuously issues control rod movement commands but does not issue boron concentration adjustment commands, the current control mode can be determined to be rod insertion mode; when the control system issues two types of commands simultaneously or alternately, the current control mode can be determined to be a mixed mode. When the nuclear power unit is operating at low power for a long period and requires fine adjustment, the control system may preferentially use boron adjustment mode to avoid control rod wear. In this case, the system recognizes the current control mode as boron adjustment mode and immediately triggers the model retrieval program.

[0033] The model retrieval program locates and retrieves the corresponding baseline reactivity prediction model from the core physics model library based on the identified current control mode. This process can be achieved through a lookup table, where a unique identifier is assigned to each control mode in the model library, and the control system directly indexes the corresponding model file based on the identifier of the current control mode. Taking the boron adjustment mode as an example, the baseline model file retrieved by the system contains a set of differential equations describing the relationship between boron concentration changes and reactivity changes, kinetic equations describing xenon poisoning formation and decay, and accumulation functions describing samarium poisoning accumulation. These mathematical models are stored in the high-performance computing unit of the control system in the form of program code or data tables, and after being retrieved, they are loaded into the current working memory, ready to receive dynamic corrections in subsequent steps.

[0034] To ensure the accuracy and timeliness of the models, the core physics model library is not static but is updated and calibrated periodically or irregularly based on actual operating data during unit operation. For example, after each refueling overhaul, the fuel assemblies loaded in the core change, and core parameters such as control rod value and boron differential value also change accordingly. At this time, the baseline model in the model library needs to be recalibrated and updated based on the new core physics design report. In addition, if there is a systematic deviation between the actual operating data and the model predictions during unit operation, an online correction procedure for the model parameters can be triggered. The parameter identification algorithm fine-tunes the key coefficients in the model to ensure that the baseline model always remains consistent with the actual physical characteristics of the core. Taking the first cycle of a nuclear power unit as an example, the initial baseline model is established based on design data. After three months of operation, sufficient measured data has been accumulated. Through comparative analysis, the xenon poisoning feedback coefficient in the model has been optimized and adjusted, further improving the accuracy of subsequent predictions.

[0035] Step S220: The first characteristic parameter, the second characteristic parameter, and the third characteristic parameter are input as dynamic correction factors into the baseline reactivity prediction model to generate a target reactivity prediction model that matches the current core state. The dynamic correction factors are input variables used to adjust the parameters of the baseline reactivity prediction model according to the actual current core state. Specifically, the first characteristic parameter is used to correct the time response parameter of reactivity change in the baseline reactivity prediction model, the second characteristic parameter is used to correct the cumulative contribution of xenon poisoning in the baseline reactivity prediction model, and the third characteristic parameter is used to correct the power spatial distribution reactivity contribution coefficient in the baseline reactivity prediction model.

[0036] In the specific implementation of step S220, the three characteristic parameters extracted in step S100 first need to be digitized and standardized. The first characteristic parameter is the reactivity change rate, usually expressed in pcm per hour. This value is calculated by the core monitoring system by dividing the reactivity difference between two consecutive sampling times by the sampling interval, which is typically set to 10 seconds or 1 minute. After moving average filtering, a stable characteristic value is formed. The second characteristic parameter is the xenon poison accumulation influence trend. This parameter is not a direct measurement but is obtained through online calculation using the core physics model. The system estimates the degree of deviation of xenon poison reactivity from the equilibrium state and its direction of change in real time based on the current power level, power history trajectory, and xenon poison kinetic equations, characterizing the dynamic contribution of xenon poison to reactivity in pcm. The third characteristic parameter is the degree of power distribution distortion. This parameter is obtained by calculating the three-dimensional neutron flux distribution data collected by the in-core detector system using a power reconstruction algorithm. It is usually characterized in the form of a power peak factor or local power gradient, dimensionless or expressed as a relative percentage.

[0037] After obtaining the three characteristic parameters mentioned above, the system inputs them as dynamic correction factors into the baseline reactivity prediction model retrieved in step S210. This input process is implemented through the parameter interface module, which maps and associates the characteristic parameters with the adjustable parameters in the baseline model. For the first characteristic parameter, the correction target is the reactivity time response parameter in the baseline model. In specific implementation, the time constant or delay element parameter in the model can be dynamically adjusted according to the magnitude of the reactivity change rate. For example, when the first characteristic parameter shows a fast reactivity change rate, the system reduces the reactivity time response constant in the model accordingly, making the model more sensitive to reactivity changes; conversely, when the reactivity change rate is slow, the time response constant increases accordingly, making the model response tend to be stable. This adjustment can be achieved through a preset mapping function, which is pre-calibrated based on the core physical characteristics and establishes a correspondence between the reactivity change rate and the time response parameter.

[0038] The second characteristic parameter corrects the cumulative contribution of xenon toxicity in the baseline model. The baseline model originally included a xenon toxicity balance calculation module based on power levels, but the theoretical xenon toxicity concentration used in this module may deviate from the actual xenon toxicity concentration in the reactor core. The input of the second characteristic parameter corrects this deviation. In practice, the second characteristic parameter can be used as the measured deviation of xenon toxicity reactivity and directly added to the xenon toxicity contribution term calculated by the model, or the initial value of the xenon toxicity kinetic equation in the model can be corrected through a weighted coefficient fusion method. When a nuclear power unit operates at low power for an extended period, if the unit reduces its power from a higher level to a lower level, the accumulation of xenon toxicity will exceed the equilibrium value. At this time, the second characteristic parameter will be positive and relatively large. The system will add this positive value to the xenon toxicity reactivity term in the model, making the predicted trend of decreasing reactivity more consistent with the actual physical process.

[0039] The third characteristic parameter corrects the power spatial distribution reactivity contribution coefficient in the baseline model. The baseline model is typically based on point reactor kinetics assumptions, neglecting the influence of power spatial distribution on reactivity. However, under conditions of significant power distribution distortion, this simplification can lead to substantial errors. The input of the third characteristic parameter corrects this error. In practice, the degree of power distribution distortion can be converted into a reactivity correction coefficient, which is positively correlated with the power peak factor. For example, when the third characteristic parameter indicates that the power peak factor exceeds a preset threshold, the system adds a power distribution reactivity contribution term to the baseline model. The magnitude of this term is proportional to the amount by which the power peak factor exceeds the threshold, thereby correcting the model's predicted value and making it more accurately reflect the impact of local power peaks on overall reactivity.

[0040] The input of the three dynamic correction factors mentioned above is not isolated, but works synergistically to adjust the baseline model. The system first converts the three characteristic parameters into corresponding correction values, and then applies these correction values ​​simultaneously to the corresponding modules of the baseline model to generate a target reactivity prediction model that perfectly matches the current core state. This generation process can be performed once per sampling period, for example, updating the target model every 1 minute or every 10 minutes to ensure that the model always remains consistent with the real-time core state. Assuming the first characteristic parameter is -10 pcm per hour at the current moment, indicating that reactivity is decreasing at a relatively fast rate; the second characteristic parameter is -300 pcm, indicating that xenon poison accumulation has significantly exceeded the equilibrium value; and the third characteristic parameter is 1.5, indicating that the power peak factor is at a high level. After the system inputs these three parameters into the baseline model, the time response parameter in the model is adjusted to a fast response mode, the xenon poison accumulation contribution increases by 300 pcm negatively, and a power distribution reactivity correction term is added. The final target reactivity prediction model can accurately reflect the true evolution trend of reactivity under the current core state.

[0041] Step S230: Based on the target reactivity prediction model, using the measured core reactivity value at the current moment as the initial value, the reactivity evolution equation described by the target reactivity prediction model is solved step by step according to the preset time step, and the predicted value of core reactivity at each time node within the preset time period is calculated.

[0042] In the specific implementation of step S230, the first step is to determine the measured value of the core reactivity at the current moment as the initial condition. This measured value is not obtained through direct measurement, but rather through real-time calculation by the core monitoring system based on parameters such as the external neutron flux detector signal, coolant temperature, and control rod position. It is typically expressed in pcm. The core monitoring system updates the calculated reactivity value every second. In step S230, the latest calculated value at the current sampling moment is used as the initial value to ensure that the prediction starting point is consistent with the actual state of the core. This initial value includes the comprehensive effect of all reactivity contributing factors at the current moment, including control rod position, boron concentration, xenon toxicity, burnup, etc., providing a benchmark for subsequent recursive calculations.

[0043] The setting of the preset time step needs to balance prediction accuracy and computational resource consumption. For long-term low-power operation scenarios, reactive changes are mainly dominated by slow time-varying factors such as xenon poisoning accumulation and fuel consumption, and the rate of change is relatively gentle. Therefore, the time step can be appropriately widened to reduce the computational burden. Typically, a time step of 15 minutes or 30 minutes is set, which can capture the detailed characteristics of xenon poisoning oscillations without causing excessive computation. The preset duration is determined based on operational decision-making needs. For example, to meet the operator's need to predict subsequent peak-shaving plans, a prediction duration of 24 hours or 48 hours can be set. In practice, these parameters can be adjusted by operation technicians through a human-machine interface according to actual needs, or the system can automatically optimize and select based on the unit's status.

[0044] The stepwise solution process employs numerical computation methods to discretize and solve the reactivity evolution equations described by the target reactivity prediction model. The target reactivity prediction model typically represents a set of ordinary differential equations, including reactivity kinetic equations, xenon toxicity kinetic equations, and temperature feedback equations. Taking the fourth-order Runge-Kutta method as an example, this method performs four-fold function evaluation within each time step, obtaining a high-precision prediction value for the next time step through weighted averaging. In specific implementation, the system starts with the measured reactivity value ρ0 at the current time t0, and calculates the reactivity value ρ1 after a time step Δt based on the reactivity rate function f(ρ,t) in the target model. This process is recursively applied, calculating t2 from t1, t3 from t2, and so on, until the entire preset time period is covered. To predict the next 24 hours, if the time step is 30 minutes, 48 ​​recursive calculations are required, ultimately obtaining a sequence of reactivity prediction values ​​for 49 time nodes from minute 1 to minute 1440.

[0045] During the step-by-step solution process, the handling of various correction factors in the target reactivity prediction model can vary depending on the implementation strategy. One implementation method is to keep the correction factors constant; that is, after generating the target model in step S220, the correction amounts corresponding to the first, second, and third feature parameters are fixed throughout the entire prediction time. This method is simple and fast, suitable for situations where correction factors change slowly or the prediction time is short. Another, more accurate implementation method is to dynamically update the correction factors; that is, during each time step calculation, the correction factors are re-evaluated based on intermediate calculation results. For example, as the recursive calculation progresses, the predicted power level changes, and the cumulative contribution of xenon toxicity also changes. At this time, the correction amount corresponding to the second feature parameter can be recalculated based on the new power level, and the model parameters can be updated to continue subsequent calculations. This method can better reflect the coupling effect of the physical process and is suitable for situations where the prediction time is long or the operating conditions change drastically. When the prediction time exceeds 12 hours and involves power platform switching, the dynamic update method can reduce the prediction error by more than 30%.

[0046] To ensure numerical stability during the solution process, the system also incorporates convergence assessment and anomaly handling mechanisms. During the calculation at each time step, the system monitors whether the rate of change in reactivity exceeds a preset physical reasonable range; for example, whether the change in reactivity within a unit step exceeds the maximum rate of change corresponding to the fuel cladding safety limit. If an anomaly occurs, such as calculation divergence or predicted values ​​exceeding physical limits, the system can automatically reduce the time step and recalculate, or terminate the current prediction and issue an alarm. Furthermore, the system retains comparison records of prediction results and actual monitored values ​​at multiple historical moments to evaluate the accuracy of the prediction model and trigger a self-calibration procedure for model parameters when necessary. If the deviation between multiple consecutive predicted values ​​and subsequent measured values ​​exceeds a preset threshold, the system will automatically reduce the prediction duration or shorten the time step to ensure the reliability of the prediction results.

[0047] Step S240: The predicted core reactivity value at each time node is calculated by performing a difference operation with the measured core reactivity value obtained by the core monitoring system at the current time, and the reactivity change at each time node relative to the current time is calculated.

[0048] In the specific implementation of step S240, it is first necessary to ensure that the two types of data involved in the difference calculation are strictly aligned on the time base. The measured value of the reactor core reactivity at the current moment is generated in real time by the reactor core monitoring system. This value is obtained by fusing multiple parameters such as the external neutron flux detector signal, coolant temperature, and control rod position, and the update frequency is usually once per second or once every 10 seconds. The predicted reactivity values ​​at each future time node calculated in step S230 are discrete point data obtained by recursively solving the target reactivity prediction model. Before performing the difference calculation, the system needs to lock the measured value at the current moment, that is, use the measured value at the moment when the solution is started in step S230 as the benchmark value to ensure that the calculation benchmark of the entire prediction sequence is consistent. Assuming that step S230 starts the solution at the hour t0 and takes 2 seconds to complete the recursive calculation for the next 24 hours, the system locks the measured reactivity value at t0 as the benchmark value, and all subsequent predicted values ​​are performed with this benchmark value to avoid benchmark drift due to updates of the measured value during the solution process.

[0049] The specific implementation of the difference operation can be a point-by-point subtraction method. That is, for each time node in the prediction sequence, the predicted reactivity value for that node is subtracted from the measured reactivity value at the current time, obtaining the change in reactivity relative to the current time. Taking the prediction of the next 24 hours with a time step of 1 hour as an example, the system will obtain 24 predicted values, corresponding to the end of the 1st hour to the end of the 24th hour. The system sequentially subtracts the measured value at the current time from each predicted value, obtaining 24 reactivity changes, forming a set of time series data. These reactivity changes have clear physical meanings and units. Positive values ​​indicate that the reactivity at that time is increasing relative to the current time, and negative values ​​indicate that the reactivity is decreasing. The magnitude of the value represents the change, and the unit is consistent with the reactivity, usually pcm. For example, if the measured value at the current time is -500 pcm and the predicted value at the end of the first hour is -520 pcm, then the reactivity change at the end of the first hour is -20 pcm, indicating that the reactivity is expected to decrease by another 20 pcm after one hour.

[0050] During the difference calculation process, the system also needs to verify the reasonableness of the calculation results. For example, it checks whether the calculated reactivity change is within the preset physical reasonable range. If there is an abnormal jump or the change exceeds the maximum change corresponding to the fuel cladding safety limit, the verification mechanism is triggered. The verification mechanism may include comparison with historical change trends and comparison with changes at adjacent time points. If the reactivity change at a certain time point changes by more than 200 pcm from the previous point, and there is currently no control operation or change in the reactor core, the system determines that the predicted value is abnormal and may trigger recalculation or mark the data at that point as unusable. In addition, the system also needs to handle possible numerical calculation errors, such as small deviations caused by floating-point operations, which can be eliminated by setting rounding precision or filtering to eliminate their impact on subsequent judgments.

[0051] After the interpolation is completed, the system organizes and stores the generated reactivity change sequence in chronological order and establishes a correlation with the preset reactivity safety threshold. The preset reactivity safety threshold is the maximum allowable reactivity change determined through back-calculation of thermal-hydraulic analysis and core physics analysis, based on safety constraints such as fuel cladding temperature limits and power peak factor limits. This threshold is typically one or more segmented thresholds; for example, short-term and long-term thresholds can be set, corresponding to safety limits at different time scales. The preset reactivity safety threshold can be set to no more than 300 pcm for positive reactivity and no more than 400 pcm for negative reactivity, or it can be dynamically adjusted according to the operational phase. The system compares each value in the reactivity change sequence with its corresponding safety threshold to identify any risk points exceeding the threshold.

[0052] To further enhance data usability, the system can also visualize the reactive change sequence, for example, displaying it in real-time as a trend curve on the operator's workstation's human-machine interface. Operators can visually see the projected trajectory of reactive changes over future time periods, as well as the relative relationship between each time point and the safety threshold. Simultaneously, the system highlights nodes exceeding the safety threshold and generates warning messages to alert operators to potential risks. If the predicted reactive change at the end of the 24th hour is -450 pcm, exceeding the -400 pcm threshold, the system will mark this point in red on the trend graph and display a warning message in the alarm window stating "Reactive change exceeds safety threshold in the next 24 hours," providing decision support for operators to take early intervention measures.

[0053] A complete method for predicting reactivity changes was constructed by retrieving a baseline model based on the current control method, dynamically correcting the model using three characteristic parameters, progressively solving for future reactivity predictions using measured values ​​as initial values, and calculating the reactivity changes at each time point relative to the current time. This method dynamically integrates the real-time core status into the prediction model, significantly improving the accuracy and adaptability of reactivity change predictions, and providing a reliable data foundation for subsequent reactivity safety assessments and control decisions.

[0054] In one embodiment of the present invention, step S300, which involves outputting a target control mode and a set of control parameters corresponding to the target control mode, and sending the set of control parameters to the reactor control system for execution, includes: Step S310: Based on the comparison result between the reactive change amount and the reactive safety threshold, select a target control method from the preset control method library, and calculate the corresponding initial execution rate based on the target control method and the reactive change amount.

[0055] First, based on the comparison between the reactivity change sequence calculated in step S200 and the preset reactivity safety threshold, it is necessary to determine whether to switch the control mode and which target control mode to select. The preset control mode library stores various control modes and their applicable conditions. For example, the boron adjustment mode is suitable for scenarios requiring fine adjustment and with ample time; the rod insertion mode is suitable for scenarios requiring rapid response and large adjustment ranges; and the hybrid mode is suitable for complex scenarios requiring a balance between response speed and adjustment accuracy. If the reactivity change prediction result shows that the reactivity will rapidly decrease by 200 pcm within the next two hours, exceeding the preset safety threshold, the system determines that the rod insertion mode, with its faster response speed, should be used as the target control mode. After selecting the target control mode, the system calculates the corresponding initial execution rate based on the characteristics of that control mode and the reactivity change. For the rod insertion mode, the calculation of the initial execution rate needs to consider the differential reactivity value of the target control rod group, i.e., the amount of reactivity change introduced by a unit rod position movement. The amount of reactivity change to be compensated is divided by the differential reactivity value to obtain the number of rods to be moved, and then divided by the preset execution time window to obtain the initial insertion rate. For boron adjustment mode, the initial execution rate calculation needs to consider the differential boron value at the current moment. The amount of reactivity change to be compensated is divided by the differential boron value to obtain the amount of boron concentration change to be adjusted. This is then divided by a preset execution time window to obtain the initial boron dilution rate or initial boration rate. For example, if the amount of reactivity change to be compensated is 200 pcm, and the differential reactivity value of the target control rod group in the current rod insertion mode is 10 pcm per step, then 20 steps are required. If the execution time window is set to 10 minutes, the initial insertion rate is 2 steps per minute. This initial execution rate, as part of the control parameter set, is output to subsequent execution stages along with the target control method.

[0056] Step S320: Start the control operation corresponding to the target control mode at the initial execution rate, and obtain the actual change rate of core reactivity in real time during each sampling period, and compare the actual change rate with the preset allowable deviation of reactivity change rate.

[0057] The system initiates the control operation corresponding to the target control mode based on the initial execution rate calculated in step S310. For the rod insertion mode, the control system sends a command to the rod control system to begin moving the target control rod group at the initial insertion rate; for the boron adjustment mode, the control system sends a command to the chemical volume control system to begin adjusting the coolant boron concentration at the initial boron dilution rate or initial boration rate. Simultaneously with the control operation, the system acquires the actual rate of change of core reactivity in real time during each sampling cycle. The sampling cycle setting needs to consider the response speed of the control system and the dynamic characteristics of the core physical processes, and is typically set to several seconds to tens of seconds; a sampling cycle of 10 seconds is possible. The actual rate of change is acquired in the same way as the first characteristic parameter in step S100, i.e., by dividing the reactivity difference between two consecutive sampling times by the sampling interval. The system also uses the expected rate of change corresponding to the current execution rate as a reference benchmark. This expected rate of change is predetermined based on the physical characteristics of the target control mode; for example, in the rod insertion mode, the expected rate of change is equal to the current insertion rate multiplied by the differential reactivity value of the target control rod group. The system compares the real-time acquired actual rate of change with a preset allowable deviation from the reactivity rate of change. This allowable deviation is a threshold preset based on fuel cladding safety limits and core dynamic characteristics, used to determine whether the actual response deviates from the expected trajectory. If the expected rate of change is -10 pcm per minute and the allowable deviation is set to ±2 pcm per minute, then the actual rate of change within the range of -8 pcm to -12 pcm per minute is considered normal.

[0058] Step S330: If the difference between the actual rate of change and the expected rate of change in the current sampling period exceeds the allowable deviation of the reactive rate of change, the execution rate adjustment amount for the next sampling period is calculated based on the difference and the preset proportional coefficient, and the execution rate of the next sampling period is reduced according to the execution rate adjustment amount.

[0059] If the difference between the actual rate of change and the expected rate of change exceeds the preset allowable deviation of the responsiveness rate of change in the current sampling period, the execution rate adjustment mechanism is triggered. The system first calculates the difference between the actual and expected rates of change. The sign of this difference reflects the direction of deviation of the actual response from the expected rate, and the magnitude reflects the degree of deviation. Based on the product of this difference and a preset proportional coefficient, the execution rate adjustment amount for the next sampling period is calculated. The proportional coefficient is a parameter pre-tuned according to the response characteristics of the control system and the core physical characteristics. It is used to control the proportional relationship between the adjustment magnitude and the deviation, avoiding over-adjustment or under-adjustment. If the actual rate of change is -6 pcm per minute and the expected rate of change is -10 pcm per minute, the difference is +4 pcm, indicating that the actual responsiveness decreases slower than expected, requiring a faster adjustment rate. If the proportional coefficient is set to 0.5, the execution rate adjustment amount is the adjustment amount corresponding to 2 pcm per minute. For the insertion mode, this adjustment amount needs to be converted into an increment of the insertion rate. The system applies the calculated execution rate adjustment amount to the execution rate of the next sampling period and continues to execute control operations according to the adjusted execution rate. This closed-loop control mechanism, which performs real-time monitoring and dynamic adjustment in each sampling period, ensures that the actual reactive change trajectory always tracks the expected trajectory, guaranteeing the accuracy of reactive control. If the difference between the actual rate of change and the expected rate of change gradually decreases and returns to within the allowable deviation range in subsequent sampling periods, the system maintains the current execution rate and continues execution; if the difference persists or further increases, the system will continue to make dynamic adjustments in each sampling period until the control operation is completed or other handling mechanisms are triggered.

[0060] Furthermore, the reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units also includes: Step S340: If the difference cannot be recovered to within the allowable deviation range of the reactivity change rate within a consecutive preset number of sampling periods, the control operation corresponding to the target control mode is suspended, and the core current control mode is restored until the actual change rate is less than the preset stable change rate threshold within a consecutive preset number of sampling periods, and then the control operation corresponding to the target control mode is restarted. The stable change rate threshold refers to the upper limit of the actual change rate used to determine whether the reactivity state has returned to stability.

[0061] First, two key counters and threshold parameters need to be set. The first is the threshold for the number of consecutive failure sampling periods, for example, five sampling periods. The second is the stable rate of change threshold, which is a very small positive number indicating that the reactive change has basically stabilized; for example, it can be set to ±1 pcm per minute or 0.02 pcm per second. When the dynamic adjustment mechanism in step S330 is activated, the system records whether the current difference has recovered to within the allowable deviation range of the reactive rate of change at the end of each sampling period. If, for a preset number of sampling periods (e.g., 5), the difference between the actual rate of change and the expected rate of change consistently fails to fall back to within the allowable deviation range, the system determines that the current control operation can no longer correct the deviation through conventional rate adjustment. Continuing execution may further amplify the deviation or even trigger a risk of reactive runaway.

[0062] Taking a rod adjustment during a long-term low-power operation of Nuclear Power Unit 1 as an example, suppose that an abnormal local power distribution in the core causes the differential value of the control rods to deviate from the expected value, resulting in the actual reactivity change rate being continuously lower than the expected value. Although the system has adjusted the insertion rate downwards for five consecutive sampling cycles according to step S330, the difference between the actual change rate and the expected value still exceeds the allowable deviation range. At this time, the system triggers the safety backoff mechanism, immediately suspending the control operation corresponding to the current target control mode, that is, stopping the movement of control rods or stopping boron concentration adjustment. At the same time, the system restores the control mode to the current core control mode that was running before step S310, that is, switching back to the original control mode (e.g., boron adjustment mode) and the original execution state under that mode. This restoration operation aims to return the core to a known and relatively stable operating state, avoiding reactivity runaway due to continuous erroneous adjustments.

[0063] After the pause, the system enters a stabilization waiting phase. During this phase, the system ceases any active power regulation operations and instead continuously monitors the actual rate of change of core reactivity in each sampling period, comparing it to a preset stable rate of change threshold. The stable rate of change threshold is a very small value, typically determined based on the core's inherent noise level or safety margin requirements, used to determine whether the reactivity has recovered from abnormal fluctuations and stabilized. For example, when the absolute value of the actual rate of change is less than the stable rate of change threshold for several consecutive sampling periods (e.g., 10 sampling periods), the system considers the core reactivity to have stabilized and no longer exhibits any abnormal trends that could lead to runaway.

[0064] Assuming the stable rate of change threshold is set to ±0.5 pcm per minute, if the system detects that the actual rate of change fluctuates within ±0.3 pcm per minute for 10 consecutive sampling cycles (each sampling cycle is 10 seconds) after a pause, the core is considered to have stabilized. At this point, the system automatically restarts the control operations corresponding to the previously paused target control method, i.e., it re-attempts to adjust reactivity using the target control method following steps S310 to S330. Upon restart, the system may recalculate the initial execution rate based on the latest reactivity change, or it may continue execution from the last paused position, depending on the implementation strategy.

[0065] Through this safety retreat and recovery mechanism, the embodiments of the present invention provide an important safety defense in the event of failure of conventional dynamic adjustment. This mechanism can promptly suspend potentially runaway control operations, giving the reactor core sufficient time to stabilize. Adjustment can only be attempted again after reactivity has returned to a stable state, thereby effectively avoiding the risk of reactivity runaway due to the continuous accumulation of control deviations. This significantly improves the robustness and safety of the control system, providing a reliable guarantee for the stable operation of nuclear power units under long-term low-power operation and frequent peak-shaving conditions.

[0066] Further, step S330, which calculates the execution rate adjustment amount for the next sampling period based on the difference and a preset scaling factor, includes: Step S331: Obtain the current safety margin level of the reactor core. The safety margin level includes a first safety level and a second safety level, with the safety margin of the first safety level being higher than that of the second safety level.

[0067] First, the current safety margin status of the reactor core needs to be assessed in real time, and a safety margin level needs to be assigned accordingly. The safety margin level is determined based on the comparison between the current operating parameters of the reactor core and preset multi-level safety thresholds. These operating parameters include, but are not limited to, key safety parameters such as fuel cladding temperature, power peak factor, coolant temperature, and core outlet temperature. The system monitors the fuel cladding temperature in real time and compares it with preset first and second safety thresholds. If the fuel cladding temperature is lower than the first safety threshold, and the power peak factor is also at a low level, the current safety margin is considered high, and the system is classified as the first safety level. If the fuel cladding temperature is between the first and second safety thresholds, or the power peak factor is close to the design limit, the current safety margin is considered low, and the system is classified as the second safety level. The first safety level corresponds to a higher safety margin, indicating that the reactor core still has a large margin to go before reaching the safety boundary; the second safety level corresponds to a lower safety margin, indicating that the reactor core is close to the safety boundary and requires more cautious control operations. Safety margin levels can be classified using a multi-parameter comprehensive evaluation method. For example, each safety parameter can be compared to a threshold and then logically combined to determine the final level. Alternatively, a weighted scoring method can be used to integrate multiple parameters into a comprehensive safety index before classifying the levels. The system updates the safety margin level at the beginning of each sampling cycle or each control cycle to ensure that the level information always reflects the latest core status.

[0068] Step S332: Match the corresponding scaling factor from the preset scaling factor matrix according to the positive or negative sign of the difference and the safety margin level.

[0069] The sign of the difference calculated in step S330 and the safety margin level determined in step S331 are used as two dimensions to match the corresponding proportional coefficients from a preset proportional coefficient matrix. The sign of the difference is automatically generated based on the relationship between the actual rate of change and the expected rate of change. When the actual rate of change is higher than the expected rate of change, it is a positive deviation, corresponding to a positive sign; when the actual rate of change is lower than the expected rate of change, it is a negative deviation, corresponding to a negative sign. The safety margin levels include a first safety level and a second safety level. The proportional coefficient matrix is ​​a two-dimensional lookup table, where rows correspond to different signs and columns correspond to different safety margin levels. Each element in the matrix is ​​a preset proportional coefficient value. The proportional coefficient matrix can be designed as follows: the proportional coefficient for a positive sign corresponding to the first safety level is 2, the proportional coefficient for a positive sign corresponding to the second safety level is 4, the proportional coefficient for a negative sign corresponding to the first safety level is 1, and the proportional coefficient for a negative sign corresponding to the second safety level is 2. This matrix structure reflects the higher sensitivity to positive deviations and the conservative handling principle for low safety margin states in nuclear reactor control. Based on the sign of the current difference and the current safety margin level, the system locates the corresponding proportional coefficient in the matrix and extracts it for subsequent calculations. The physical meaning of this proportional coefficient is the adjustment range of the execution rate corresponding to a unit deviation; its magnitude directly affects the strength of the control action.

[0070] Step S333: Calculate the basic adjustment amount based on the proportional coefficient and the difference.

[0071] Based on the difference between the proportional coefficient obtained in step S332 and the value calculated in step S330, the basic adjustment amount is calculated through multiplication. The formula for calculating the basic adjustment amount can be expressed as the product of the proportional coefficient and the difference. Its value reflects the magnitude of the execution rate adjustment required to correct the deviation under the current deviation level and current control sensitivity. If the current difference is +5 pcm and the proportional coefficient obtained through matching is 2, then the basic adjustment amount is the adjustment corresponding to 10 pcm. For the rod insertion mode, this basic adjustment amount needs to be converted into an increment of the insertion rate. For example, based on the differential reactivity value of the current control rod group, 10 pcm is converted into the corresponding rod position movement rate increment. For the boron adjustment mode, this basic adjustment amount needs to be converted into an increment of the boron dilution rate or boronization rate. For example, based on the current boron differential value, 10 pcm is converted into the corresponding boron concentration change rate increment. The calculation of the basic adjustment amount is the core step in the execution rate adjustment, and its accuracy directly affects the control effect. When calculating the basic adjustment amount, the system also needs to consider the compatibility between the physical unit of the execution rate adjustment amount and the control system command format, and perform unit conversion or dimension normalization when necessary.

[0072] Step S334: If the sign is positive and the safety margin level is the second safety level, then calculate the execution rate adjustment amount based on the preset safety enhancement coefficient. The safety enhancement coefficient is greater than 1.

[0073] After the basic adjustment amount is calculated, it is further determined whether a special enhancement condition is met. This special enhancement condition refers to the combination of a positive sign for the difference and a safety margin level of the second safety level, i.e., the actual rate of change is higher than the expected rate of change and the core is in a low safety margin state. This combination represents the most dangerous operating condition requiring enhanced control, because a positive deviation means that the reactive change is too rapid and may lead to an increase in power, while a low safety margin means that the core's ability to withstand disturbances is weak. When the two are combined, the risk increases significantly. When the system identifies that this special condition is met, the basic adjustment amount calculated in step S333 is multiplied by a preset safety enhancement coefficient to obtain the final execution rate adjustment amount. The safety enhancement coefficient is a value greater than 1, for example, it can be set to 1.5 or 2.5. Its function is to further amplify the adjustment range to ensure that the control effect is strong enough in the most dangerous situation and can quickly suppress the expansion trend of the positive deviation. If the basic adjustment amount is 10 pcm and the safety enhancement coefficient is set to 1.5, the final execution rate adjustment amount is 15 pcm, which is 50% higher than the basic adjustment amount. If the specific enhancement conditions are not met, such as a positive deviation but a safety level of Level 1, a negative deviation but a safety level of Level 2, or a negative deviation and a safety level of Level 1, then the basic adjustment amount is directly used as the final execution rate adjustment amount, and no further enhancement processing is performed. This conditional enhancement mechanism achieves differentiated allocation of control intensity, concentrating the strongest control action in the most dangerous operating conditions, ensuring safety while avoiding over-adjustment when the safety margin is sufficient.

[0074] This invention, through the introduction of two dimensions—safety margin level and deviation direction—constructs a differentiated proportional coefficient matching mechanism based on a proportional coefficient matrix. Furthermore, a safety enhancement coefficient is superimposed under the most critical operating conditions, enabling refined calculation of the execution rate adjustment. This mechanism allows the control system to dynamically adjust the control intensity based on the real-time safety status of the reactor core and the deviation direction. It employs stronger control actions when the safety margin is low and assigns higher control weights during positive deviations, significantly improving the safety adaptability and robustness of the control system. This provides more refined technical support for the safe and stable operation of nuclear power units under long-term low-power operation and frequent peak-shaving conditions.

[0075] Further, step S310, which calculates the corresponding initial execution rate based on the target control method and the reactive change, includes: Step S311: Obtain the control characteristic reference curve corresponding to the target control mode. The control characteristic reference curve pre-calibrates the correspondence between the execution rate and the change in reactivity under the reference core state.

[0076] First, it is necessary to obtain the control characteristic baseline curves corresponding to the target control mode. These baseline curves are obtained in advance through theoretical calculations and experimental calibration, and are used to describe the correspondence between the execution rate and the change in reactivity under a reference core state. The reference core state is usually selected as the unit design baseline state, such as typical operating conditions like initial cycle of a new core, rated power operation, and xenon poisoning balancing. For the boron adjustment mode, the control characteristic baseline curves describe the relationship between the boron dilution rate or boronization rate and the change in reactivity, i.e., the change in reactivity introduced by a change in boron concentration per unit time. For the rod insertion mode, the control characteristic baseline curves describe the relationship between the control rod insertion rate and the change in reactivity, i.e., the change in reactivity introduced by a control rod movement per unit time. The control characteristic baseline curves under the boron adjustment mode can be obtained through the boron differential value function, which, based on the core physical design parameters, gives the change in reactivity corresponding to a unit change in boron concentration under different boron concentrations. These baseline curves are stored in the control system's model library in the form of data tables or functions for subsequent steps.

[0077] Step S312: Obtain the current state parameters of the reactor core. The current state parameters of the reactor core include at least the current burn-up depth and the current average temperature of the coolant.

[0078] The core status parameters at the current moment are obtained from the core monitoring system. These parameters include at least the current burnup depth and the current average coolant temperature. Burnup depth characterizes the degree to which core fuel has been consumed, typically expressed as equivalent full-power days or megawatt-days per ton of uranium. This parameter is obtained based on power history accumulation through a core burnup calculation program. Average coolant temperature refers to the average temperature of the reactor coolant in the hot and cold sections, reflecting the thermohydraulic state of the core. Burnup depth can be obtained in real time from the core burnup tracking system; for example, the current burnup depth is 300 equivalent full-power days. Average coolant temperature is measured by temperature sensors arranged in the coolant loop; for example, the current average coolant temperature is 295°C. These two parameters are the main factors affecting control characteristics. Burnup depth affects the control rod value and boron differential value, while average coolant temperature affects the moderator temperature coefficient and reactivity feedback characteristics.

[0079] Step S313: Calculate the state deviation between the reference core state and the current core state based on the current burnup depth and the current average coolant temperature, and determine at least one correction coefficient based on the state deviation.

[0080] Based on the current burnup depth and current average coolant temperature obtained in step S312, the state deviation between the reference core state and the current core state is calculated, and at least one correction coefficient is determined based on the state deviation. The calculation of the state deviation requires a pre-established mapping relationship based on the core physical model. For example, the burnup deviation and temperature deviation can be calculated using a burnup correction function and a temperature correction function, respectively. The burnup deviation characterizes the degree of deviation of the current burnup depth from the reference burnup depth, and the temperature deviation characterizes the degree of deviation of the current average coolant temperature from the reference temperature. If the reference burnup depth is set to zero (new core), and the current burnup depth is 300 equivalent full-power days, then the burnup deviation is 300 equivalent full-power days; if the reference average coolant temperature is 290℃, and the current temperature is 295℃, then the temperature deviation is +5 degrees Celsius. Based on these deviations, the system calculates the corresponding correction coefficients using a preset correction coefficient function. For example, the burnup correction coefficient can be designed as a function that decreases linearly with increasing burnup depth, and the temperature correction coefficient can be designed as a function that changes non-linearly with increasing temperature. The number of correction coefficients can be a single comprehensive coefficient, or multiple coefficients can be set separately for different control characteristics. For example, the boron differential value correction coefficient and the control rod value correction coefficient can be calculated independently.

[0081] Step S314: Correct the control characteristic baseline curve using the correction coefficient to obtain the target control characteristic curve that matches the current core state.

[0082] Using one or more correction coefficients calculated in step S313, the control characteristic baseline curve obtained in step S311 is corrected to generate a target control characteristic curve that matches the current core state. The correction method depends on the type of correction coefficient and the form of the baseline curve. If a single comprehensive correction coefficient is used, all points on the baseline curve can be multiplied by the coefficient to achieve overall scaling of the curve. If multiple independent correction coefficients are used, different dimensions of the curve can be corrected separately. For example, for the baseline curve in the boron adjustment mode, the ordinate of the curve can be adjusted using the boron differential value correction coefficient, and the slope of the curve can be adjusted using the temperature correction coefficient. If the burnup correction coefficient is 0.9, it means that the boron differential value at the current burnup depth is reduced by 10% compared to the reference state; if the temperature correction coefficient is 1.2, it means that the reactivity feedback is slightly enhanced at the current temperature. The system multiplies the execution rate value corresponding to each reactivity change on the baseline curve by the burnup correction coefficient and then by the temperature correction coefficient to obtain the corrected target control characteristic curve. This curve reflects the true correspondence between the execution rate and the reactivity change under the current actual core state, providing an accurate basis for subsequent initial execution rate determination.

[0083] Step S315: Based on the amount of change in reactivity, determine the corresponding initial execution rate on the target control characteristic curve using linear interpolation.

[0084] Based on the reactivity change calculated in step S200, the corresponding initial execution rate is determined on the target control characteristic curve generated in step S314 using linear interpolation. The target control characteristic curve is typically stored as discrete data points, for example, a set of execution rate values ​​corresponding to reactivity change values ​​at certain intervals. When the reactivity change to be determined is exactly equal to the x-coordinate of a data point, the y-coordinate value corresponding to that data point is directly read as the initial execution rate. When the reactivity change is between two adjacent data points, the system uses linear interpolation to calculate the y-coordinate value of the intermediate point based on the coordinates of the two adjacent points. Taking the boron adjustment mode of a nuclear power unit as an example, assuming the data points stored on the target control characteristic curve are: a reactivity change of -50 pcm corresponds to a boron dilution rate of 0.5 ppm per minute, and a reactivity change of -100 pcm corresponds to a boron dilution rate of 1.0 ppm per minute. If the current reactivity change to be compensated is -75 pcm, then the corresponding boron dilution rate is calculated to be 0.75 ppm per minute through linear interpolation. This calculated initial execution rate is the rate value used to start execution in the subsequent step S320. For the bar insertion mode, the linear interpolation process is similar, yielding an initial insertion rate. The system uses this calculated initial execution rate as part of the control parameter set and outputs it to subsequent execution stages.

[0085] By acquiring the baseline control characteristic curve corresponding to the target control mode, calculating correction coefficients based on state parameters such as current burnup depth and average coolant temperature, and dynamically correcting the baseline curve to obtain the target control characteristic curve, a complete adaptive calculation method for the initial execution rate is constructed through linear interpolation. This method fully considers the impact of core burnup variations and thermal-hydraulic state changes on control characteristics, making the determination of the initial execution rate more accurate and adaptable to the actual core state, thus laying a reliable foundation for subsequent precise control.

[0086] In one embodiment of the present invention, step S300, which outputs a target control mode and a set of control parameters corresponding to the target control mode, includes: Step S301: Read the mode identification information contained in the target control mode, and identify the control mode to which the target control mode belongs based on the mode identification information. The control mode includes one of boron adjustment mode, rod insertion mode or hybrid mode.

[0087] First, the system reads the mode identifier information contained in the target control mode determined in step S300. The target control mode is assigned a specific mode identifier during generation, which is stored or transmitted as a data field bound to the control mode itself. The mode identifier information can be a simple numerical code, a character label, or an enumeration type, used to uniquely distinguish different control modes. The control system can set the number 1 to represent boron adjustment mode, the number 2 to represent rod insertion mode, and the number 3 to represent a hybrid mode. When step S300 outputs the target control mode, the mode identifier is output along with it as part of the control mode data packet. After receiving the target control mode, the system first parses the data packet, extracts the mode identifier field, and then identifies the specific control mode to which the current target control mode belongs based on a preset identifier-mode lookup table. This identification process is a prerequisite for subsequent parameter generation, ensuring that subsequent steps use the correct parameter generation rules. For example, if the parsed mode identifier is the number 1, the system determines that the current target control mode is boron adjustment mode; if it is the number 2, it determines it is rod insertion mode; and if it is the number 3, it determines it is hybrid mode. The identification result will be used as the input parameter for the next step.

[0088] Step S302: Based on the control mode, retrieve the corresponding parameter generation rule from the preset parameter generation rule library.

[0089] Based on the control mode identified in step S301, the corresponding parameter generation rules are retrieved from the preset parameter generation rule base. The parameter generation rule base is a pre-built knowledge base stored in the control system, where a corresponding set of parameter generation rules is established for each control mode. The parameter generation rule set for the boron adjustment mode includes specific rules on how to calculate the target boron concentration change based on the reactivity change, how to determine the boron dilution rate or boronization rate, and how to consider xenon toxicity compensation and fuel consumption compensation. The parameter generation rule set for the rod insertion mode includes specific rules on how to determine the target control rod group based on the reactivity change, how to calculate the target rod position change, how to determine the insertion rate, and how to consider the control rod group selection order. The parameter generation rule set for the hybrid mode is more complex, including rules on how to allocate the reactivity share between boron adjustment and rod insertion, how to determine the execution sequence of the two, and how to coordinate the synergistic effect of the two control methods. The parameter generation rule base is stored in the form of a structured data table or an executable program module, with each rule set corresponding to a unique mode identifier. Based on the control mode identifier identified in step S301, the system indexes and locates the corresponding rule set in the rule base and loads it into the current working memory for execution in the next step.

[0090] Step S303: Based on the reactive change and parameter generation rules, calculate the set of control parameters corresponding to the target control mode.

[0091] Based on the reactivity change calculated in step S200 and the parameter generation rules retrieved in step S302, a set of control parameters corresponding to the target control mode is calculated and generated. The calculation process fully follows the algorithms and logic defined in the selected rule set. Taking the boron adjustment mode as an example, the system first determines the total amount of reactivity that needs to be compensated based on the reactivity change, and then calculates the target total reactivity compensation by combining the xenon toxicity reactivity value and burnup reactivity value at the current moment. Next, the differential boron value at the current moment is obtained, and the target total reactivity compensation is divided by the differential boron value to obtain the target boron concentration change. Finally, based on the target boron concentration change and the preset execution time window, the target boron dilution rate or target boration rate is calculated. These parameters together constitute the control parameter set for the boron adjustment mode. Taking the rod insertion mode as an example, the system first obtains the current control rod position distribution and the reactivity value curve of each control rod group in the core, and determines the target control rod group to be inserted based on the reactivity change. Then, the differential reactivity value of the target control rod group at the current position is obtained, and the reactivity change is divided by the differential reactivity value to obtain the target rod position change. Finally, based on the target rod position change and the preset insertion rate constraints, the target insertion rate is calculated and used as part of the rod insertion mode control parameter set. Taking the hybrid mode as an example, the system needs to simultaneously invoke the generation rules of the boron adjustment mode and the rod insertion mode, and calculate the execution parameters and timing relationships of the boron adjustment operation and the rod insertion operation according to the preset cooperative allocation strategy. The generated control parameter set will be encapsulated into a standard instruction format and sent to the actuators through the control system network to complete the control operation of the reactor.

[0092] By reading the mode identifier of the target control mode to identify the control mode, retrieving the corresponding parameter generation rules according to the control mode, and then calculating and generating a specific set of control parameters based on the reactive change, a complete mode-adaptive control parameter generation mechanism is constructed. This mechanism ensures that different control modes can use dedicated rules to generate parameters, improving the accuracy and adaptability of parameter calculation and laying the foundation for subsequent precise control execution.

[0093] Furthermore, when the target control mode is boron adjustment mode, step S303 calculates the control parameter set corresponding to the target control mode based on the reactivity change and parameter generation rules, including: Step S303a1: Obtain the xenon toxicity reactivity value and the fuel consumption reactivity value at the current moment.

[0094] First, the current xenon toxicity reactivity value and the current burnup reactivity value are obtained from the core monitoring system or core physics calculation program. The xenon toxicity reactivity value refers to the change in reactivity caused by the accumulation or decay of the fission product xenon-135. This value is not obtained through direct measurement but is calculated in real-time by the core physics model based on the current power level, power history trajectory, and xenon toxicity kinetic equations. Taking the long-term low-power operation of a nuclear power unit as an example, when the unit reduces its power from a higher level to a lower level, xenon toxicity accumulation will exceed the equilibrium value, resulting in a negative xenon toxicity reactivity value with a large absolute value, indicating a significant negative impact of xenon toxicity on reactivity. The burnup reactivity value refers to the change in reactivity caused by nuclear fuel consumption and the accumulation of fission products. This value is calculated based on the core burnup calculation program, according to the accumulated equivalent full-power days and the burnup reactivity coefficient. The burnup reactivity value is usually negative and gradually decreases with increasing operating time, reflecting the long-term impact of the gradual consumption of core fuel on reactivity. Obtaining these two parameters is the basis for subsequent calculations of the total reactivity to be compensated.

[0095] Step S303a2: Calculate the total target compensation reactivity based on the reactivity change, the xenon toxicity reactivity value at the current moment, and the fuel consumption reactivity value at the current moment.

[0096] Based on the reactivity change calculated in step S200, the current xenon toxicity reactivity value obtained in step S303a1, and the current fuel consumption reactivity value, the target total reactivity compensation is calculated. The reactivity change is the future reactivity value that needs compensation predicted in step S200, for example, a reactivity decrease of -100 pcm to be compensated within the next hour. The current xenon toxicity reactivity value reflects the reactivity deficit already caused by xenon toxicity, for example, a current xenon toxicity reactivity value of -300 pcm. The current fuel consumption reactivity value reflects the reactivity deficit already caused by fuel consumption, for example, a current fuel consumption reactivity value of -500 pcm. When calculating the target total reactivity compensation, these three components need to be considered comprehensively to ensure that the compensation operation can both meet future change requirements and appropriately consider the current existing deficit state. A typical calculation method is to add the reactivity change to a certain combination of the current xenon toxicity reactivity value and the current fuel consumption reactivity value. For example, if the required reactivity change is -100 pcm, the current xenon toxicity reactivity is -300 pcm, and the current fuel consumption reactivity is -500 pcm, then the target total reactivity compensation can be calculated as the negative of the sum of these three values, i.e., +900 pcm. This indicates that +900 pcm of reactivity needs to be introduced to balance the current deficit and meet future demands. In actual calculations, different combinations can be used depending on the specific control strategy. For example, only the future trend of xenon toxicity changes may be considered without compensating for the current total xenon toxicity deficit.

[0097] Step S303a3: Obtain the boron differential value at the current moment.

[0098] The boron differential value is obtained from the core monitoring system or the core physics parameter database at the current moment. The boron differential value refers to the change in reactivity introduced by a unit change in boron concentration, usually expressed in pcm per ppm. This parameter is not a fixed constant but a function of the core state, mainly affected by factors such as burn-up depth, coolant temperature, and control rod position. In the initial stage of a new core, the boron differential value may be -10 pcm per ppm. As burn-up deepens, the boron concentration gradually decreases, and the boron differential value changes accordingly. The system obtains the current boron differential value through interpolation calculation by real-time monitoring of parameters such as current boron concentration and burn-up depth, combined with a pre-calibrated boron differential value curve. Accurate acquisition of this parameter is crucial for subsequent calculations of boron concentration changes, as the accuracy of the boron differential value directly affects the accuracy of boron adjustment.

[0099] Step S303a4: Calculate the change in target boron concentration based on the total target compensating reactivity and the differential value of boron at the current moment.

[0100] Based on the target total compensating reactivity calculated in step S303a2 and the current boron differential value obtained in step S303a3, the target boron concentration change is calculated. The calculation method is to divide the target total compensating reactivity by the current boron differential value. Since the units of reactivity and boron differential value are consistent, the result of the division operation is the boron concentration value that needs to be changed, in ppm. For example, if the target total compensating reactivity is +900 pcm and the current boron differential value is -10 pcm per ppm, then the target boron concentration change is -90 ppm, indicating that the boron concentration needs to be reduced by 90 ppm to introduce +900 pcm of reactivity. It should be noted that the sign of the calculation result has a clear physical meaning: a positive value indicates that the boron concentration needs to be increased (performing a borylation operation), and a negative value indicates that the boron concentration needs to be decreased (performing a dilution operation).

[0101] Step S303a5: Calculate the target boron dilution rate or target boronization rate based on the target boron concentration change and the preset execution time window, and use the target boron dilution rate or target boronization rate as the boron adjustment mode parameter in the control parameter set.

[0102] Based on the target boron concentration change calculated in step S303a4 and the preset execution time window, the target boron dilution rate or target boration rate is calculated and used as the boron adjustment mode parameter in the control parameter set. The execution time window is a preset time length based on operational requirements and the control system's response capability, such as 10 minutes, 30 minutes, or 1 hour. Dividing the target boron concentration change by the execution time window yields the boron concentration value that needs to be changed per unit time, i.e., the boron dilution rate or boration rate. If the target boron concentration change is -90 ppm and the execution time window is set to 30 minutes, the target boron dilution rate is -3 ppm per minute, meaning that continuous dilution at a rate of 3 ppm per minute is required for 30 minutes to ultimately achieve the target reduction of 90 ppm. If the target boron concentration change is positive, the calculated value is the boration rate. The calculated rate value is formatted into a standard control command and sent to the chemical volume control system for execution via the control system network. Simultaneously, this rate value is also recorded in the control parameter set as the basis for this boron adjustment operation.

[0103] This invention provides a complete method for generating boron adjustment mode parameters by acquiring xenon toxicity and burnup reactivity values, calculating the target compensation reactivity amount based on the reactivity change, determining the target boron concentration change based on the boron differential value, and finally calculating the boron dilution rate or boronization rate according to the execution time window. This method fully considers the impact of xenon toxicity accumulation and burnup effects on reactivity, achieving refined reactivity compensation and providing an accurate and reliable technical means for reactivity control under long-term low-power operation conditions of nuclear power units.

[0104] Furthermore, when the target control mode is the insertion mode, step S303 calculates the control parameter set corresponding to the target control mode based on the reactive change and parameter generation rules, including: Step S303b1: Obtain the current control rod position distribution of the reactor core and the reactivity value curve of each control rod group.

[0105] First, the current control rod position distribution and reactivity value curves for each control rod group are retrieved from the core monitoring and control system database. The control rod position distribution refers to the current insertion position of each control rod group in the core, usually expressed as steps or percentages. Control rods are typically divided into several groups, such as adjustment groups and shutdown groups, each containing multiple control rods. The system monitors the current position of each group of control rods in real time. The reactivity value curve for each control rod group is obtained beforehand through core physics calculations and experimental calibration, describing the corresponding relationship between the reactivity change introduced by a unit position change at different positions. These curves are usually stored in the physical parameter library of the control system in the form of data tables or functions, reflecting the integral and derivative characteristics of the control rod group. For example, the reactivity value curve of the adjustment group may show a higher derivative value in the intermediate position region, while the derivative value is lower at full insertion or full extraction positions. The system retrieves this data, providing a basis for subsequent target control rod group selection and position change calculation.

[0106] Step S303b2: Based on the amount of reactivity change and the reactivity value curve of each control rod group, match and determine the target control rod group to be inserted.

[0107] Based on the reactive change calculated in step S200 and the reactive value curve of each control rod group, the system matches and determines the most suitable target control rod group for this insertion operation from multiple control rod groups. The matching process needs to comprehensively consider multiple factors, including the differential reactive value of each control rod group at the current position, the remaining adjustment margin of each control rod group, the usage history of each control rod group, and preset rod group selection rules. If the reactive change to be compensated is -200 pcm, the system first calculates the reactive change introduced by each control rod group moving a unit distance at the current position, i.e., the differential reactive value. Then, considering the remaining movable range of each group, it evaluates whether the moving distance required for each group to individually complete 200 pcm compensation is within the allowable range. Simultaneously, it refers to preset rod group usage order rules, such as prioritizing the use of the adjustment group and then the secondary adjustment group, to ensure uniform wear of each rod group. Through comprehensive evaluation of multiple parameters, the system selects the most suitable control rod group as the target control rod group. If a single group cannot meet the requirements, the system may choose a combination of multiple groups for further processing in subsequent steps.

[0108] Step S303b3: Obtain the differential reactivity value of the target control rod group at the current rod position.

[0109] Based on the target control rod group determined in step S303b2, the differential reactivity value of the control rod group at the current rod position is obtained. The differential reactivity value refers to the change in reactivity introduced by a unit rod position movement (e.g., one step), typically expressed in pcm per step. This parameter is not a fixed constant but a function of rod position variation; therefore, it needs to be extracted in real-time from the reactivity value curve of the group based on the current rod position. If the reactivity value curve shows a differential value of 10 pcm per step at rod position 200 steps and 8 pcm per step at rod position 250 steps, and if the current rod position is 220 steps, the system calculates the corresponding differential reactivity value at that position through linear interpolation, for example, 9.5 pcm per step. The accuracy of this value directly affects the accuracy of subsequent rod position change calculations and is one of the key parameters for generating the rod insertion mode parameters.

[0110] Step S303b4: Calculate the target rod position change based on the reactivity change and the differential reactivity value of the target control rod group.

[0111] Based on the reactive change obtained in step S200 and the differential reactive value of the target control rod group obtained in step S303b3, the target rod position change is calculated. The calculation method is to divide the reactive change by the differential reactive value. Since the reactive change and differential reactive value have the same unit, the result of the division operation is the number of rods that need to be moved, in steps. For example, if the reactive change to be compensated is -200 pcm and the current differential reactive value is 9.5 pcm per step, then the target rod position change is -21.05 steps, which, after rounding, is approximately -21, indicating that the control rod group needs to be moved 21 steps in the insertion direction. The sign of the calculation result has a clear physical meaning: a negative value indicates the insertion direction, and a positive value indicates the extraction direction. This target rod position change is the basis for subsequent calculations of the insertion rate.

[0112] Step S303b5: Calculate the target insertion rate based on the target rod position change and the preset insertion rate constraint, and use the target insertion rate as the rod insertion mode parameter in the control parameter set.

[0113] Based on the target rod position change calculated in step S303b4 and the preset insertion rate constraints, the target insertion rate is calculated and used as the rod insertion mode parameter in the control parameter set. The insertion rate constraints are preset limits based on reactor safety requirements and equipment performance, including the maximum allowable insertion rate, minimum allowable insertion rate, and acceleration limits. To ensure that the thermal stress of the fuel cladding is within a safe range, the control rod insertion rate is typically limited to no more than 24 steps per minute. If the target rod position change is 21 steps, the system can choose to complete it within one control cycle. For example, if the execution time window is set to 1 minute, the target insertion rate is 21 steps per minute, which is within the constraint range and can be directly adopted. If the target rod position change is large, such as 100 steps, the minimum execution time required needs to be calculated based on the maximum allowable rate, or the movement process can be divided into stages. The calculated target insertion rate will be formatted into a standard control command and sent to the rod control system for execution via the control system network. Simultaneously, this rate value is also recorded in the control parameter set as the basis for this rod insertion operation.

[0114] Furthermore, when the target control mode is a hybrid mode, step S303 calculates the control parameter set corresponding to the target control mode based on the reactive change and parameter generation rules, including: Step S303c1: Based on the reactive change and the first characteristic parameter, calculate the initial rod position change and initial insertion rate corresponding to the rod insertion mode using the rod insertion response function.

[0115] First, based on the reactivity change calculated in step S200 and the first characteristic parameter extracted in step S100, the initial rod position change and initial insertion rate corresponding to the rod insertion mode are calculated using the rod insertion response function. The design goal of the rod insertion response function is to enable the rod insertion operation to quickly respond to the immediate demand component in the reactivity change, meeting dynamic response requirements. This function takes the reactivity change and the first characteristic parameter as inputs, where the first characteristic parameter characterizes the current reactivity change rate and reflects the core's immediate sensitivity to control actions. The rod insertion response function can be designed to divide the reactivity change by a combination of the first characteristic parameter and a preset scaling factor to obtain the initial rod position change; then, the initial rod position change is divided by a preset rod insertion response time window to obtain the initial insertion rate. This calculation method ensures that the amplitude and rate of the rod insertion operation match the current dynamic characteristics of the reactivity. The initial rod position change represents the number of steps required to move, and the initial insertion rate represents the number of steps moved per unit time; both together constitute the basic control parameters of the rod insertion mode.

[0116] Step S303c2: Initiate the control operation corresponding to the insertion mode, and monitor the actual change rate of core reactivity and xenon poison reactivity value in real time during the execution process.

[0117] The control operation corresponding to the rod insertion mode is initiated based on the initial insertion rate calculated in step S303c1, i.e., a command is sent to the rod control system to begin moving the target control rod group. Simultaneously with the rod insertion operation, the system monitors two key parameters in real time during each sampling cycle: the actual rate of change of core reactivity and the xenon toxicity reactivity value. The monitoring method for the actual rate of change is consistent with the acquisition method of the first characteristic parameter in step S100, obtained by dividing the reactivity difference at consecutive sampling times by the sampling interval. The xenon toxicity reactivity value is obtained through online calculation using the core physics model, reflecting the contribution of the current xenon toxicity concentration to reactivity. The sampling cycle can be set to 10 seconds, and the system updates the actual rate of change and the xenon toxicity reactivity value every 10 seconds. This real-time monitoring data will serve as input for subsequent boron adjustment compensation calculations to determine the actual effect of the rod insertion operation and its impact on the xenon toxicity state. The execution of the rod insertion operation and real-time monitoring are performed synchronously, forming a continuous data acquisition and state awareness channel.

[0118] Step S303c3: Based on the deviation between the actual rate of change and the expected rate of change, as well as the changing trend of the xenon toxicity reactivity value, the dynamic boron concentration compensation amount corresponding to the boron adjustment mode is calculated in real time using the boron adjustment compensation function.

[0119] Based on the first deviation between the actual and expected rates of change obtained from real-time monitoring in step S303c2, and the changing trend of xenon toxic reactivity values, the dynamic boron concentration compensation amount corresponding to the boron adjustment mode is calculated in real-time using the boron adjustment compensation function. The design goal of the boron adjustment compensation function is to enable the boron adjustment operation to dynamically compensate for the xenon toxicity oscillation trend introduced by the rod insertion operation. The first deviation between the actual and expected rates of change reflects the degree of deviation between the actual response of the rod insertion operation and the theoretical expectation. For example, if the expected rate of change is -10 pcm per minute and the actual rate of change is -8 pcm per minute, then the first deviation is +2 pcm, indicating that the actual rate of decrease in reactivity is slower than expected. The changing trend of xenon toxic reactivity values ​​reflects the disturbance of the xenon toxicity balance caused by the rod insertion operation. For example, the rod insertion operation may change the power distribution and thus affect the xenon toxicity generation rate. The boron adjustment compensation function integrates these two deviations. For example, the first deviation is multiplied by the feedback compensation coefficient to obtain the feedback compensation component, and the change in xenon toxicity reactivity value is multiplied by the xenon toxicity compensation coefficient to obtain the xenon toxicity compensation component. The two are then added together to obtain the dynamic boron concentration compensation amount. This compensation amount represents the amount of reactivity that needs to be additionally compensated by the boron adjustment operation at the current moment, measured in pcm. This real-time compensation mechanism enables the boron adjustment operation to dynamically track the actual effect of the insertion rod operation and its impact on xenon toxicity, achieving real-time coupling between the two.

[0120] Step S303c4 converts the dynamic boron concentration compensation amount into a real-time boron dilution rate or a real-time boronization rate, which, together with the initial rod position change and the initial insertion rate, forms a set of mixed-mode control parameters.

[0121] The dynamic boron concentration compensation calculated in step S303c3 is converted into a real-time boron dilution rate or a real-time boronizing rate, and together with the initial rod position change and initial insertion rate obtained in step S303c1, they form the hybrid mode control parameter set. The process of converting the dynamic boron concentration compensation into a real-time rate requires considering the boron differential value at the current moment. For example, the compensation is divided by the boron differential value to obtain the boron concentration value to be changed, and then divided by a preset control period to obtain the rate of change per unit time. If the compensation is positive, it indicates the need to introduce positive reactivity, which is converted into a boron dilution rate; if the compensation is negative, it indicates the need to introduce negative reactivity, which is converted into a boronizing rate. If the dynamic boron concentration compensation is +50 pcm and the current boron differential value is -10 pcm per ppm, then the boron concentration needs to be reduced by 5 ppm. If the control period is set to one minute, the real-time boron dilution rate is 5 ppm per minute. This real-time rate, together with the initial rod position change and the initial insertion rate, constitutes the hybrid mode control parameter set. The insertion parameter is responsible for rapid response, and the boron adjustment parameter is responsible for dynamic compensation; both are executed collaboratively within the same time window. This parallel execution method allows the insertion rod operation and boron adjustment operation to act on the reactor core simultaneously. The insertion rod meets the immediate needs, while the boron adjustment tracks and compensates for the xenon poisoning oscillations introduced by the insertion rod in real time, achieving true dynamic coupling control.

[0122] This invention rapidly generates insertion rod parameters and initiates execution via an insertion rod response function. During execution, it monitors reactivity and xenon toxicity changes in real time. A boron adjustment compensation function dynamically calculates the compensation amount and converts it into a real-time boron adjustment rate, ultimately forming a hybrid control parameter set for parallel execution of insertion rods and boron adjustment. This method abandons the traditional fixed-share allocation approach, employing a real-time coupling strategy with insertion rods as the primary control and dynamic boron adjustment compensation. This allows the two control methods to continuously interact and coordinate during execution, significantly improving the adaptability and accuracy of hybrid control. It effectively suppresses xenon toxicity oscillations that may be caused by insertion rod operation, providing an innovative technical solution for the complex control requirements of nuclear power units under long-term low-power operation conditions.

[0123] Furthermore, the stud response function is expressed as: .

[0124] .

[0125] in, This represents the initial change in rod position. This is the scaling factor for the insertion rod response. This represents the change in reactivity. The first characteristic parameter, The initial insertion rate, This is the response time of the insertion rod.

[0126] The design of the rod position response function embodies a rapid response mechanism to the immediate demand component of the reactive change. In this function, the initial rod position change ΔH is determined by the reactive change Δρ. target Divide by the first characteristic parameter R1 and multiply by the plug response scaling factor K rod The first characteristic parameter R1 characterizes the current rate of reactivity change. Its magnitude reflects the immediate sensitivity of the reactor core to control actions. When the rate of reactivity change is fast, R1 is large, and the initial rod position change corresponding to the same amount of reactivity change is correspondingly smaller, avoiding over-adjustment; when the rate of reactivity change is slow, R1 is small, and the initial rod position change is correspondingly larger, ensuring sufficient adjustment. Rod insertion response scaling factor K rod It is a preset constant used to adjust the overall response amplitude of the insertion rod operation; its value can be tuned according to the stack characteristics and control requirements. Initial insertion rate V rod Then, the initial rod position change ΔH is divided by the rod response time T. rod Obtain the plug response time T rod This function pre-sets a time window based on the control system's response capability and core safety requirements, ensuring that the insertion operation is completed within a reasonable timeframe. Through this function, the insertion operation can dynamically adjust the amplitude and rate of regulation according to the real-time characteristics of reactivity changes, achieving a rapid and precise response to changes in reactivity.

[0127] Furthermore, the boron adjustment compensation function is expressed as: .

[0128] .

[0129] .

[0130] .

[0131] .

[0132] in, This is the second deviation between the xenon toxicity reactivity value and the preset expected xenon toxicity reactivity value. This represents the xenon toxicity reactivity value. The preset expected xenon toxicity value, This refers to the reactive bias corresponding to the first deviation between the actual rate of change and the expected rate of change. This represents the actual reactivity value of the reactor core at the current moment. This represents the expected reactivity value at the current moment. The total amount of reactivity that needs to be compensated for in order to adjust boron The preset xenon toxicity compensation coefficient, The preset feedback compensation coefficient, This is the dynamic boron concentration compensation amount. The differential value of boron at the current moment, This refers to the real-time boron dilution rate or real-time boration rate. The preset control period. Dynamic boron concentration compensation amount. The positive or negative value is used to distinguish the direction of operation: if If it is a positive value, then For the real-time boron dilution rate, if If it is a negative value, then This represents the real-time boronization rate.

[0133] The boron adjustment compensation function is designed to reflect a dynamic compensation mechanism for the xenon toxicity oscillation trend introduced by the insertion rod operation. The function first calculates two key deviations: a second deviation Δρ between the xenon toxicity reactivity value and the preset expected xenon toxicity reactivity value. xe And the reactivity deviation Δρ corresponding to the first deviation between the actual reactivity value and the expected reactivity value. fb The second deviation Δρ xe This reflects the degree of deviation of the current xenon toxicity state from the expected equilibrium state; the first deviation corresponds to the reactivity deviation Δρ. fb This reflects the degree of deviation between the actual response of the insertion rod operation and the theoretical expectation. These two deviations are multiplied by the preset xenon poisoning compensation coefficient K. xe and feedback compensation coefficient K fb The residues are then added together to obtain the total reactive power Δρ that needs to be compensated for when adjusting boron levels. boron Xenon toxicity compensation coefficient K xe The feedback compensation coefficient K determines the strength of the compensation for xenon poisoning deviation caused by boron tuning. fb This determines the strength of the correction to the actual response deviation caused by boron tuning. The total reactive power Δρ that needs to be compensated for during boron tuning is... boron Divide by the differential boron value W at the current moment b The dynamic boron concentration compensation amount ΔC was obtained. b Dynamic boron concentration compensation amount ΔC b The positive and negative values ​​are used to distinguish the operation direction. A positive value indicates that the boron concentration needs to be reduced to introduce positive reactivity, corresponding to the real-time boron dilution rate; a negative value indicates that the boron concentration needs to be increased to introduce negative reactivity, corresponding to the real-time boration rate. Finally, the dynamic boron concentration compensation amount ΔC is... b Divide by the preset control period Δt to obtain the real-time boron dilution rate or real-time boration rate V. boron This function enables the boron adjustment operation to track changes in xenon toxicity and response deviations during the insertion process in real time, dynamically calculate the amount of boron concentration adjustment needed for compensation, and achieve precise compensation for disturbances caused by the insertion operation.

[0134] By leveraging the synergistic effect of the rod insertion response function and the boron adjustment compensation function, this invention achieves real-time coupled control of rapid rod insertion response and dynamic boron adjustment compensation. The rod insertion response function ensures rapid adjustment to the immediate demands of reactivity changes, meeting the dynamic response requirements of nuclear power units under frequent peak-shaving conditions. The boron adjustment compensation function, by monitoring the actual response deviation and xenon toxicity change trend during rod insertion in real time, dynamically calculates and applies boron concentration compensation, effectively suppressing xenon toxicity oscillations that may be caused by rod insertion operation. This combined fast and slow, master-slave collaborative control strategy fully utilizes the advantage of rapid rod insertion response while leveraging the strong compensation capability of boron adjustment operation to eliminate the side effects of rod insertion, significantly improving the accuracy and stability of hybrid mode control. This provides reliable technical support for the reactivity control of nuclear power units under long-term low-power operation and frequent peak-shaving conditions.

[0135] Accordingly, a second aspect of the present invention provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor. The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, cause the at least one processor to perform the aforementioned reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit.

[0136] Accordingly, a third aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit.

[0137] The embodiments of the present invention aim to protect a reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units, which has the following effects: 1. By extracting three characteristic parameters in real time—the rate of reactivity change, the trend of xenon poison accumulation, and the degree of power distribution distortion—and combining them with the current core control method, dynamic prediction of future reactivity changes and comparison with safety thresholds are achieved. This realizes the transformation from passive response to active prediction, significantly improving the predictability and accuracy of reactivity control, and effectively solving the problem that existing technologies cannot identify the risk of fuel cladding damage in advance due to the use of static rules or empirical parameters. 2. By introducing a real-time feedback adjustment mechanism during the execution of the control parameter set, the deviation between the actual rate of change and the expected rate of change is dynamically monitored and adaptively corrected. When the deviation continues to exceed the standard, the execution is automatically paused and restored to the original control mode to wait for stability. This achieves closed-loop control and safety assurance of the execution process, significantly improves the stability and reliability of the control operation, and effectively reduces the risk of human error caused by parameter fluctuations or execution deviations. 3. By constructing differentiated parameter generation rules for boron adjustment mode, rod insertion mode and hybrid mode, and adopting a real-time coupled control strategy of fast rod insertion response and dynamic boron adjustment compensation in hybrid mode, the advantages of different control methods are complemented and synergistically optimized, which significantly improves the control flexibility and adaptability of the reactor under long-term low-power operation conditions, and effectively solves the contradiction that a single control mode cannot simultaneously meet the requirements of response speed and safety margin.

[0138] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0139] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0140] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0141] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit, characterized in that, Includes the following steps: Real-time acquisition of the current operating status parameters of the reactor core, and extraction of a first characteristic parameter to characterize the current rate of reactivity change, a second characteristic parameter to characterize the trend of the influence of xenon poisoning accumulation on reactivity, and a third characteristic parameter to characterize the degree of distortion of the reactor core power distribution from the operating status parameters; Based on the first feature parameter, the second feature parameter, the third feature parameter, and the current core control mode, calculate the change in reactivity of the core reactivity at several time nodes relative to the current time within a preset future time period, and compare the change in reactivity with a preset reactivity safety threshold. If any of the reactivity changes exceeds the reactivity safety threshold, a target control mode and a set of control parameters corresponding to the target control mode are output, and the set of control parameters is sent to the reactor control system for execution.

2. The reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units according to claim 1, characterized in that, The process of outputting a target control mode and a set of control parameters corresponding to the target control mode, and sending the set of control parameters to the reactor control system for execution, includes: Based on the comparison result between the reactivity change amount and the reactivity safety threshold, a target control method is selected from the preset control method library, and the corresponding initial execution rate is calculated based on the target control method and the reactivity change amount. The control operation corresponding to the target control mode is initiated and executed at the initial execution rate, and the actual rate of change of core reactivity is obtained in real time during each sampling period. The actual rate of change is compared with the preset allowable deviation of reactivity rate. If the difference between the actual rate of change and the expected rate of change in the current sampling period exceeds the allowable deviation of the reactive rate of change, the execution rate adjustment amount for the next sampling period is calculated based on the difference and a preset proportional coefficient, and the execution rate for the next sampling period is reduced according to the execution rate adjustment amount.

3. The reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units according to claim 2, characterized in that, Also includes: If the difference cannot be recovered to the allowable deviation range of the reactivity change rate within a consecutive preset number of sampling periods, the control operation corresponding to the target control mode is suspended and the core is restored to the current control mode until the actual change rate is less than the preset stable change rate threshold within a consecutive preset number of sampling periods, and then the control operation corresponding to the target control mode is restarted. The stable rate of change threshold refers to the upper limit of the actual rate of change used to determine whether the reactive state has returned to stability.

4. The reactive adaptive control method for long-term low-power operation of pressurized water reactor nuclear power units according to claim 2, characterized in that, The step of calculating the execution rate adjustment amount for the next sampling period based on the difference and a preset proportional coefficient includes: Obtain the current safety margin level of the reactor core, wherein the safety margin level includes a first safety level and a second safety level, and the safety margin of the first safety level is higher than that of the second safety level; Based on the sign of the difference and the safety margin level, the corresponding scaling factor is matched from the preset scaling factor matrix; Based on the proportional coefficient and the difference, the basic adjustment amount is calculated; If the positive or negative sign is a positive sign and the security margin level is the second security level, then the execution rate adjustment amount is calculated in combination with the preset security enhancement coefficient; The security enhancement coefficient is greater than 1.

5. The reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit according to claim 2, characterized in that, The calculation of the corresponding initial execution rate based on the target control method and the reactive change amount includes: Obtain the control characteristic reference curve corresponding to the target control mode. The control characteristic reference curve pre-calibrates the correspondence between the execution rate and the amount of reactivity change under the reference core state. Obtain the current state parameters of the reactor core, which include at least the current burn-up depth and the current average coolant temperature. Based on the current burnup depth and the current average coolant temperature, calculate the state deviation between the reference core state and the current core state, and determine at least one correction coefficient based on the state deviation. The control characteristic baseline curve is corrected using the correction coefficient to obtain a target control characteristic curve that matches the current core state; Based on the amount of reactive change, the corresponding initial execution rate is determined by linear interpolation on the target control characteristic curve.

6. The reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit according to any one of claims 1-5, characterized in that, The output target control mode and the corresponding set of control parameters include: Read the mode identification information contained in the target control method, and identify the control mode to which the target control method belongs based on the mode identification information. The control mode includes one of boron adjustment mode, rod insertion mode or hybrid mode. According to the control mode, the corresponding parameter generation rule is retrieved from the preset parameter generation rule library; Based on the reactivity change and the parameter generation rule, calculate the set of control parameters corresponding to the target control method.

7. The reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit according to claim 6, characterized in that, When the target control mode is boron adjustment mode, the calculation of the control parameter set corresponding to the target control mode based on the reactivity change and the parameter generation rule includes: Obtain the xenon toxicity reactivity value and the fuel consumption reactivity value at the current moment; The target compensation reactivity amount is calculated based on the reactivity change, the xenon toxicity reactivity value at the current moment, and the fuel consumption reactivity value at the current moment. Obtain the differential value of boron at the current moment; The change in target boron concentration is calculated based on the total target compensating reactivity and the differential value of boron at the current moment. Based on the target boron concentration change and the preset execution time window, the target boron dilution rate or target boronization rate is calculated, and the target boron dilution rate or target boronization rate is used as the boron adjustment mode parameter in the control parameter set.

8. The reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit according to claim 6, characterized in that, When the target control mode is the plug-in mode, the calculation of the control parameter set corresponding to the target control mode based on the reactive change and the parameter generation rule includes: Obtain the current control rod position distribution in the reactor core and the reactivity value curve for each control rod group; Based on the reactivity change and the reactivity value curve of each control rod group, the target control rod group to be inserted is determined. Obtain the differential reactivity value of the target control rod group at the current rod position; The target rod position change is calculated based on the reactivity change and the differential reactivity value of the target control rod group. Based on the target rod position change and the preset insertion rate constraint, the target insertion rate is calculated and used as the rod insertion mode parameter in the control parameter set.

9. The reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit according to claim 6, characterized in that, When the target control mode is a hybrid mode, the calculation of the control parameter set corresponding to the target control mode based on the reactive change and the parameter generation rule includes: Based on the reactive change and the first characteristic parameter, the initial rod position change and initial insertion rate corresponding to the rod insertion mode are calculated using the rod insertion response function; Initiate and execute the control operation corresponding to the insertion mode, and monitor the actual rate of change of core reactivity and xenon toxicity reactivity value in real time during the execution process; Based on the deviation between the actual rate of change and the expected rate of change, and the changing trend of the xenon toxicity reactivity value, the dynamic boron concentration compensation amount corresponding to the boron adjustment mode is calculated in real time using the boron adjustment compensation function. The dynamic boron concentration compensation is converted into a real-time boron dilution rate or a real-time boronization rate, which, together with the initial rod position change and the initial insertion rate, constitutes a hybrid mode control parameter set.

10. The reactive adaptive control method for long-term low-power operation of a pressurized water reactor nuclear power unit according to claim 9, characterized in that, The response function of the insertion rod is expressed as follows: ； ； in, This represents the initial change in rod position. This is the scaling factor for the insertion rod response. This represents the change in reactivity. The first characteristic parameter, The initial insertion rate, This refers to the response time of the insertion rod. The boron adjustment compensation function is expressed as follows: ； ； ； ； ； in, This is the second deviation between the xenon toxicity reactivity value and the preset expected xenon toxicity reactivity value. This represents the xenon toxicity reactivity value. The preset expected xenon toxicity value, This refers to the reactive bias corresponding to the first deviation between the actual rate of change and the expected rate of change. This represents the actual reactivity value of the reactor core at the current moment. This represents the expected reactivity value at the current moment. The total amount of reactivity that needs to be compensated for in order to adjust boron The preset xenon toxicity compensation coefficient, The preset feedback compensation coefficient, This is the dynamic boron concentration compensation amount. The differential value of boron at the current moment, This refers to the real-time boron dilution rate or real-time boration rate. The preset control cycle; The dynamic boron concentration compensation amount The positive and negative values ​​are used to distinguish the direction of operation: if If it is a positive value, then This is the real-time boron dilution rate; if If it is a negative value, then This represents the real-time boronization rate.

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