First calibration method for power range of RPN system after refueling start, computer storage medium and terminal equipment

Abstract

The invention relates to an RPN system power range first calibration method after refueling starting, a computer storage medium and a terminal device, and the method comprises the steps: continuously monitoring the unit power in the first starting power increasing process after refueling of a nuclear power unit, and enabling the unit power to rise from the first set power to the nth set power in the process that the unit power rises from the first set power to the nth set power, acquiring in-pile power and axial power data corresponding to each set power; wherein n is a natural number greater than 3; and determining the coefficient of the RPN power range according to the in-pile power and the axial power data corresponding to the first set power to the nth set power. According to the invention, the power range coefficient of each range measurement channel in the nuclear power unit can be calibrated without actively introducing xenon oscillation.

Description

Technical Field

[0001] The invention relates to the field of nuclear power technology, and in particular to a method for first calibration of power range of an RPN system after starting a fuel change, a computer storage medium and a terminal device. Background Art

[0002] Since nuclear power units need to be refueled regularly, and each refueling may cause significant changes in the neutron flux level and power distribution in the reactor, or the instrument of the nuclear instrument system (RPN system) may drift as the equipment is running, causing the neutrons leaking from the reactor pressure vessel to be captured by the power range detector and the response current generated by the reaction changes accordingly, which in turn causes the original power range coefficient of the unit to be inaccurate, causing the RPN system to be unable to accurately indicate the nuclear power and axial power deviation calibration. At this time, it is necessary to perform a power range calibration test. In the relevant technology, the power range coefficient (coefficients include α, K) is currently mainly calibrated by the xenon oscillation test method. U , K L ) for calibration, while the xenon oscillation method mainly introduces disturbances to the reactor by manually lifting and inserting the temperature control rod (i.e., R rod) at the current power level, creates xenon oscillations, and then performs flux diagram measurement tests under 6 to 8 different power distribution states to complete the calibration of the power range coefficient. Therefore, the xenon oscillation test calibration method not only requires active xenon oscillations, but also manually introduces disturbances and power distribution changes to the reactor by manually lifting and inserting the R rod, resulting in the unit to continuously and dynamically adjust the boron concentration in the primary circuit in order to maintain the reactor at the current power level and near the criticality, which will lead to the generation of a large amount of radioactive waste liquid. There are defects such as long calibration time (generally ranging from 6 to 9 hours), high calibration risk (reactor power oscillation will weaken the self-convergence. If it is superimposed with other abnormalities in the unit or improper intervention or control by the staff, it is very easy to cause serious core control consequences), large amount of radioactive waste liquid generated, and low economic benefits of nuclear power plants. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for first calibration of the power range of an RPN system after starting a material change, a computer storage medium and a terminal device.

[0004] The technical solution adopted by the present invention to solve the technical problem is to construct a method for first calibration of the power range of the RPN system after the material change is started, comprising:

[0005] During the first start-up and power increase process of the nuclear power unit after refueling, the unit power is continuously monitored to obtain the corresponding in-core power and axial power data at each set power during the process of the unit power increasing from the first set power to the nth set power; wherein n is a natural number greater than 3;

[0006] The coefficient of the RPN power range is determined according to the in-pile power and axial power data corresponding to the first set power to the nth set power.

[0007] Preferably, the axial power data includes an upper detector response current and a lower detector response current;

[0008] The step of determining the coefficient of the RPN power range according to the axial power data and the in-stack power corresponding to the first set power to the nth set power comprises:

[0009] Substitute the axial power data and the in-pile power corresponding to each set power into the set equation to obtain n sets of equations;

[0010] Fitting the n sets of equations by the least square method to obtain coefficients of the RPN power range;

[0011] Wherein, the setting equation is expressed as:

[0012] W m Indicates the internal power of the stack corresponding to the mth set power, m = 1, 2, 3, ..., n, ΔI m represents the axial power deviation corresponding to the mth set power. The coefficients of the RPN power range include α, K U , K L , I U represents the upper detector response current, I L represents the lower detector response current.

[0013] Preferably, the step of obtaining the in-stack power and axial power data corresponding to each set power further includes:

[0014] Acquiring operating data of the nuclear power unit;

[0015] Determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data;

[0016] The acquisition of the in-core power and axial power data is allowed only when the operating condition of the nuclear power unit is stable at the corresponding set power.

[0017] Preferably, the n is equal to 4, and the first set power to the nth set power are respectively equal to 50% FP, 75% FP, 85% FP, and 100% FP.

[0018] Preferably, the operation data includes turbine control mode information, power control rod group position information, temperature control rod group position information, primary circuit pressure, reactor coolant average temperature and reactor coolant reference temperature;

[0019] The step of determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data comprises:

[0020] When the nuclear power unit is at the first set power or the third set power, determine whether the steam turbine is in the automatic load control mode according to the steam turbine control mode information, determine whether the power control rods in the power control rod group are in a completely core-extracted state according to the power control rod group position information, determine whether the primary loop pressure is within the set pressure range, determine whether the temperature control rod group is within the set adjustment band according to the temperature control rod group position information, and determine whether the difference between the reactor coolant average temperature and the reactor coolant reference temperature is less than the set temperature;

[0021] When the steam turbine is in automatic load control mode, the power control rod is in a completely core-extracted state, the first-loop pressure is within a set pressure range, the temperature control rod group is within a set step range and the difference is less than a set temperature, it is determined that the operating condition of the nuclear power unit is stable at the corresponding set power.

[0022] Preferably, the operation data also includes power variation information, boron dilution record information and axial power deviation information;

[0023] The step of determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data comprises:

[0024] When the nuclear power unit is at the second set power or the fourth set power, determine whether the steam turbine is in the automatic load control mode according to the steam turbine control mode information, determine whether the power control rod is in a completely core-extracted state according to the power control rod group position information, determine whether the primary loop pressure is within the set pressure range, determine whether the temperature control rod group is within the set adjustment band according to the temperature control rod group position information, determine whether the number of steps of the single-direction continuous change of the rod position of the temperature control rod group within the first set time is greater than the set number of steps according to the temperature control rod group position information, determine whether the difference between the reactor coolant average temperature and the reactor coolant reference temperature is less than the set temperature, determine whether the time the nuclear power unit remains in the corresponding power range is greater than the corresponding time length according to the power change information, determine whether the nuclear power unit has performed a manual boron dilution operation within the second set time according to the boron dilution record information, and determine whether the change rate of the axial power deviation is less than the set power change rate according to the axial power deviation information;

[0025] When the steam turbine is in automatic load control mode, the power control rod is in a state of being completely lifted out of the core, the primary circuit pressure is within the set pressure range, the temperature control rod group is within the set adjustment band range, the number of steps of continuous unidirectional change of the rod position of the temperature control rod group within the first set time is not greater than the set number of steps, the difference is less than the set temperature, the nuclear power unit remains within the corresponding power range for a time greater than the corresponding time length, the nuclear power unit has not performed manual boron dilution operation within the second set time and the change rate of the axial power deviation is less than the set power change rate, it is determined that the operating condition of the nuclear power unit is stable under the corresponding set power.

[0026] Preferably, when the nuclear power unit is at the second setting power, the corresponding power range is 73% FP to 77% FP, and the corresponding duration is 6 hours;

[0027] When the nuclear power unit is at the 4th setting power, the corresponding power range is 98% FP to 102% FP, and the corresponding duration is 48 hours.

[0028] Preferably, the set pressure range is 153 bar.g to 154 bar.g, the set adjustment band range is between ±6 steps in the middle of the adjustment band, the set number of steps is 2 steps, the set temperature is 0.5°C, the first set time and the second set time are 6h, and the set power change rate is 0.3% FP / h.

[0029] The present invention also constructs a computer storage medium storing a computer program, which implements the steps of the method for first calibration of the power range of the RPN system after the material change is started when the computer program is run.

[0030] The present invention also constructs a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for first calibration of the power range of the RPN system after the material change is started are implemented.

[0031] The implementation of the present invention has the following beneficial effects: the power range coefficient of each range measurement channel in the nuclear power unit can be calibrated without actively introducing xenon oscillation, replacing the current xenon oscillation test calibration method, avoiding the introduction of disturbances to the reactor, and reducing the risk of reactivity control. It has the advantages of high safety in the calibration process, short calibration time, and low radioactive waste liquid production rate, and plays a positive role in providing safety and economic benefits for nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0033] Figure 1 It is a program flow chart of a method for first calibration of the power range of the RPN system after starting the material change in one embodiment of the present invention;

[0034] Figure 2 It is a continuous flow chart for determining whether the power of a nuclear power unit is in a stable state in one embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram of the structure of a terminal device in one embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0037] It should be noted that the flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0038] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0039] Figure 1 The present invention is a flowchart of a method for first calibration of the power range of the RPN system after refueling startup in one embodiment of the present invention. The method for first calibration of the power range of the RPN system after refueling startup can be applied to the Hualong One nuclear power unit, and can calibrate the power range coefficients of each range measurement channel (including source range measurement channel, intermediate range measurement channel and power range measurement channel) in the nuclear power unit without actively introducing xenon oscillation.

[0040] It should be noted that the power range coefficient is one of the important parameters required for the RPN system to realize reactor power monitoring. For its application principle in the RPN system, please refer to the existing technology and will not be repeated here.

[0041] Please refer to Figure 1 The method for first calibrating the power range of the RPN system after the material replacement is started may include step S10 and step S20.

[0042] Step S10 includes: continuously monitoring the unit power during the first startup and power increase process after the nuclear power unit is refueled, so as to obtain the corresponding in-core power and axial power data at each set power during the process of the unit power increasing from the first set power to the nth set power; wherein n is a natural number greater than 3.

[0043] It can be understood that this step utilizes the characteristics of the various power operating conditions of the reactor that are inevitably present in the first startup and power increase process of the nuclear power unit after material replacement to obtain the data required for calibrating the power range coefficient, so there is no need to introduce reactor power disturbance by lifting and inserting the temperature control rod.

[0044] Step S20 includes: determining the coefficient of the RPN power range according to the in-pile power and axial power data corresponding to the first set power to the nth set power.

[0045] In one embodiment, the axial power data may include an upper detector response current and a lower detector response current. Accordingly, the step of determining the coefficient of the RPN power range according to the axial power data and the in-stack power corresponding to the first set power to the nth set power may include: substituting the axial power data and the in-stack power corresponding to each set power into the set equation to obtain n sets of equations; fitting the n sets of equations by the least squares method to obtain the coefficient of the RPN power range.

[0046] Among them, the setting equation can be expressed as:

[0047] W m Indicates the internal power of the stack corresponding to the mth set power, m = 1, 2, 3, ..., n, ΔI m Indicates the axial power deviation corresponding to the mth set power. The coefficients of the RPN power range include α, K U , K L , I U represents the upper detector response current, I L Indicates the lower detector response current.

[0048] It should be noted that the upper detector response current and the lower detector response current can be obtained through the existing range measurement channel, wherein the range measurement channel includes an upper detector distributed in the upper part of the core and a lower detector distributed in the lower part of the core, and the upper detector response current corresponds to the upper detector output that can represent the upper power size in the core, and the lower detector response current corresponds to the lower detector output that can represent the lower power size in the core. As for the specific arrangement and working principle of the upper and lower detectors, please refer to the prior art, which will not be repeated here. In this embodiment, the difference between the upper detector response current and the lower detector response current can be subtracted, and after being processed by the core measurement system (i.e., the RIC system), the axial power deviation and the power size in the core can be obtained.

[0049] The method of implementing curve fitting based on the least squares method can refer to the existing technology and will not be described here. Of course, after substituting the axial power data and the in-pile power corresponding to each set power into the set equation, n sets of equations will be obtained. By solving the n sets of equations, the coefficients of the RPN power range can also be calculated.

[0050] During the operation of a nuclear power plant, the core power will fluctuate to a certain extent. Of course, the core power is usually stable. However, when obtaining the in-core power and axial power data, the core power happens to be in a relatively large fluctuation condition, which will reduce the reference significance of the in-core power and axial power data, thereby reducing the confidence of the power range coefficient obtained after calibration. In view of this, in one embodiment, in the process of obtaining the in-core power and axial power data corresponding to each set power, the following steps can also be performed: Figure 2 Steps S11 to S13 are shown to ensure that the power of the nuclear power unit is in a stable state during the acquisition of the in-core power and axial power data.

[0051] Step S11 includes: obtaining the operating data of the nuclear power unit. The operating data may include turbine control mode information, power control rod group position information, temperature control rod group position information, primary circuit pressure, reactor coolant average temperature, reactor coolant reference temperature, power change information, boron dilution record information and axial power deviation information. It should be noted that the operating data of the nuclear power unit can be obtained by communicating with the existing systems of the nuclear power plant (including the nuclear power plant DCS system, RIC system, RPN system, etc.).

[0052] Step S12 includes: determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data.

[0053] In one embodiment, n is equal to 4. Accordingly, the first set power to the nth set power are equal to 50% FP, 75% FP, 85% FP, and 100% FP, respectively. It should be noted that FP (Full Power) represents the power output when the nuclear power unit is running at full power, that is, the maximum output power of the nuclear power unit. The first set power to the fourth set power are respectively set to 50% FP, 75% FP, 85% FP, and 100% FP because these power values ​​have relatively large reference significance. For example, when the power of the nuclear power unit rises to 50% FP, it means that the nuclear power unit can safely complete the startup process. The power value before 50% FP is in a rapid rise stage and is far from the power value of daily operation (during daily operation, the power of the nuclear power unit is usually between 80% FP and 100% FP). Therefore, the data obtained from the power platform less than 50% FP is of little reference significance. For 75% FP, in order to ensure safety, the nuclear power unit should not increase power at a fast speed all the time. At the 75% FP power platform, the nuclear power unit is already in a high load state. Therefore, the nuclear power unit usually stays at the 75% FP power platform for a period of time to ensure that the related equipment of the nuclear power unit is normal before the nuclear power unit continues to increase power. Therefore, in this embodiment, the in-core power and axial power data can be obtained in the steady state of the stay. Usually, after the 75% FP power platform is completed, if the nuclear power unit is correct, it will gradually rise to 100% FP. Since the span between 75% FP and 100% FP is large, the unit power fluctuation uncertainty is large, which is not conducive to improving the calibration accuracy. Therefore, in this embodiment, the 85% FP power platform is also set as the power point for obtaining the in-core power and axial power data to eliminate the fluctuation uncertainty of the unit power as much as possible. For 100% FP, it is usually the power platform where the nuclear power unit is located most of the time. Therefore, in this embodiment, it is preferred to obtain the in-core power and axial power data once at 100% FP.

[0054] It is easy to understand that the larger the value of n, the larger the amount of data collected during the calibration process, which is more conducive to improving the calibration accuracy. Among them, 75% FP and 100% FP are power platforms that need to stay when the nuclear power unit is normally started after refueling. This embodiment obtains relevant data at these two power platforms, which helps to save calibration time and improve calibration efficiency. 50% FP and 85% FP are power platforms that do not stop. Their main function is to increase the margin of the data and eliminate the uncertainty of unit power fluctuations. Of course, other power value platforms can also be used to replace 50% FP and 85% FP, but it is necessary to follow the first setting power between 50% FP and 75% FP, and the third setting power between 75% FP and 100% FP, which helps to improve the calibration accuracy.

[0055] Whether the operating condition of the nuclear power unit is stable at each set power can be determined by executing steps S121 to S124.

[0056] Step S121 includes: when the nuclear power unit is at the first set power or the third set power, determining whether the turbine is in automatic load control mode according to the turbine control mode information, determining whether the power control rods in the power control rod group are in a completely core-extracted state according to the power control rod group position information, determining whether the primary circuit pressure is within the set pressure range, determining whether the temperature control rod group is within the set adjustment band according to the temperature control rod group position information, and determining whether the difference between the average reactor coolant temperature and the reactor coolant reference temperature is less than the set temperature.

[0057] It should be noted that the steam turbine being in automatic load control mode indicates that the load of the nuclear power unit is in a controllable and stable state, which can indirectly indicate that the power of the nuclear power unit (or the power in the reactor) is also in a controllable state.

[0058] Since the insertion and removal of the power control rods will directly affect the power of the nuclear power unit, the power control rod position is in a state of being completely pulled out of the core (taking Hualong One as an example, the power control rod position is at step 225, which means it is in a state of being completely pulled out of the core) to ensure that the power control rod group will not affect the power of the nuclear power unit, that is, to avoid unnecessary disturbances in the power of the nuclear power unit. The power control rod group position information can be obtained from the rod control system, which includes the real-time position information of each power control rod in the power control rod group.

[0059] The temperature control rod group is mainly used to control the average temperature of the primary circuit and ensure the thermal balance between the primary and secondary circuits. Therefore, the temperature control rod group should not be lifted or inserted significantly, and the adjustment band range can be set to the middle of the adjustment band of the temperature control rod group ±6 steps. This can ensure that the temperature control rod group is adjusted within a smaller range to avoid drastic power fluctuations of the nuclear power unit. It should be noted that the adjustment band is the operating range of the adjustment control rod assembly. The position information of the temperature control rod group and the adjustment band can be obtained in real time from the rod control system. The range span of the adjustment band is usually 24 steps.

[0060] The changes in the primary circuit pressure and the difference between the average temperature of the reactor coolant and the reference temperature of the reactor coolant can indirectly reflect whether the power of the nuclear power unit is controllable. Therefore, it is necessary to ensure that the primary circuit pressure is within the set pressure range and that the difference between the average temperature of the reactor coolant and the reference temperature of the reactor coolant is less than the set temperature.

[0061] In one embodiment, the set pressure range may be 153 bar.g to 154 bar.g, and the set temperature may be 0.5°C.

[0062] Step S122 includes: when the steam turbine is in automatic load control mode, the power control rod is in a state of being completely out of the core, the primary circuit pressure is within the set pressure range, the temperature control rod group is within the set step range and the difference is less than the set temperature, it is determined that the operating condition of the nuclear power unit is stable at the corresponding set power.

[0063] Furthermore, if the steam turbine is not in automatic load control mode, the power control rod is not in a completely core-extracted state, the primary circuit pressure is not within the set pressure range, the temperature control rod group is not within the set step range, or the difference is not less than the set temperature (that is, when any of the above items is true), it is determined that the nuclear power unit is unstable under the operating conditions corresponding to the set power.

[0064] More specifically, when the operating condition of the nuclear power unit is unstable at the first set power or the third set power, an alternative stable operating condition can be constructed by executing the following steps: if it is determined that the operating condition of the nuclear power unit is unstable at the first set power, the sum of the current first set power and the first preset power value is determined as the latest first set power, and step S121 is performed with the latest first set power; if it is determined that the operating condition of the nuclear power unit is unstable at the third set power, the sum of the current third set power and the second preset power value is determined as the latest third set power, and step S121 is performed with the latest third set power. The first preset power value and the second preset power value can range from 2% FP to 6% FP.

[0065] Step S123 includes: when the nuclear power unit is at the second set power or the fourth set power, determining whether the steam turbine is in the automatic load control mode according to the steam turbine control mode information, determining whether the power control rod is in a completely core-extracted state according to the power control rod group position information, determining whether the primary circuit pressure is within the set pressure range, determining whether the temperature control rod group is within the set adjustment band range according to the temperature control rod group position information, determining whether the number of steps of the single-direction continuous change of the rod position of the temperature control rod group within the first set time is greater than the set number of steps according to the temperature control rod group position information, determining whether the difference between the average temperature of the reactor coolant and the reference temperature of the reactor coolant is less than the set temperature, determining whether the time the nuclear power unit remains in the corresponding power range is greater than the corresponding time length according to the power change information, determining whether the nuclear power unit has performed a manual boron dilution operation within the second set time according to the boron dilution record information, and determining whether the change rate of the axial power deviation is less than the set power change rate according to the axial power deviation information.

[0066] Since the second set power and the fourth set power need to stay, compared with step S121, step S123 also determines whether the number of steps of continuous unidirectional change of the rod position of the temperature control rod group within the first set time is greater than the set number of steps, whether the time the nuclear power unit remains in the corresponding power range is greater than the corresponding time length, whether the nuclear power unit has performed manual boron dilution operation within the second set time, and whether the change rate of the axial power deviation is less than the set power change rate.

[0067] Among them, the continuous change in one direction refers to the operation of continuous insertion or continuous lifting of the temperature control rod, that is, the temperature control rod is inserted continuously for more than 2 steps or continuously lifted for more than 2 steps, which can be considered as continuous change in one direction. It is easy to understand that when the temperature control rod group changes continuously in one direction, it will cause a more obvious increase or decrease in the average temperature of a circuit, which reflects that the power of the nuclear power unit is in an unstable working condition. Among them, the first setting time can be 6h (hours), and the setting number of steps can be 2 steps.

[0068] Since the second set power and the fourth set power need to stay for a certain period of time, it is possible to determine whether the power of the nuclear power unit is stable by judging whether the time the nuclear power unit remains in the corresponding power range is greater than the corresponding duration. Further, when the nuclear power unit is at the second set power and the second set power is equal to 75% FP, the corresponding power range is 73% FP to 77% FP, and the corresponding duration is 6h. When the nuclear power unit is at the fourth set power and the fourth set power is equal to 100% FP, the corresponding power range is 98% FP to 102% FP, and the corresponding duration is 48h.

[0069] Under normal operation of the unit, if there is a small disturbance in the core, the automatic boron dilution operation (i.e., boration or dilution operation) will have a relatively small impact on the power, so it will not affect the calibration. However, if the operator actively and manually performs the boron dilution operation, the amount is generally large, which will cause a large disturbance to the core power and have a negative impact on the calibration. Therefore, it is necessary to ensure that no manual boron dilution operation has been performed within a certain period of time. Among them, the second set time can be 6h.

[0070] During the stay period, the power of the nuclear power unit is relatively stable, and theoretically, the change rate of its axial power deviation is small, so whether the power of the nuclear power unit is stable can be determined by judging whether the change rate of the axial power deviation is less than the set power change rate. The set power change rate can be 0.3% FP / h.

[0071] Step S124 includes: when the steam turbine is in automatic load control mode, the power control rod is in a state of being completely lifted out of the core, the primary circuit pressure is within the set pressure range, the temperature control rod group is within the set adjustment band range, the number of steps of continuous single-direction change of the rod position of the temperature control rod group within the first set time is not greater than the set number of steps, the difference is less than the set temperature, the nuclear power unit remains within the corresponding power range for a time greater than the corresponding time length, the nuclear power unit has not performed manual boron dilution operation within the second set time and the change rate of the axial power deviation is less than the set power change rate, it is determined that the operating condition of the nuclear power unit is stable at the corresponding set power.

[0072] Further, if the steam turbine is not in the automatic load control mode, the power control rod is not in the state of being completely lifted out of the core, the primary circuit pressure is not within the set pressure range, the temperature control rod group is not within the set adjustment band range, the number of steps of the continuous change of the rod position of the temperature control rod group in one direction within the first set time is greater than the set number of steps, the difference is not less than the set temperature, the time the nuclear power unit remains within the corresponding power range is not greater than the corresponding time, the nuclear power unit has not performed manual boron dilution operation within the second set time, or the change rate of the axial power deviation is not less than the set power change rate, it is determined that the working condition of the nuclear power unit is unstable at the corresponding set power. Since the second set power and the fourth set power need to stay for a certain time, when it is determined that the working condition of the nuclear power unit is unstable at the second set power or the fourth set power, it can be allowed to obtain the in-core power and axial power data only after the working condition of the nuclear power unit can fully meet the judgment requirements of step S123 (that is, all the criteria in step S123 are established) by waiting or the staff actively operating.

[0073] Step S13 includes: obtaining the in-core power and axial power data is allowed only when the operating condition of the nuclear power unit is stable under the corresponding set power.

[0074] It can be understood that in this step, when the operating conditions of the nuclear power unit are stable at the first set power to the nth set power, a set of in-core power and axial power data will be obtained accordingly.

[0075] The present invention also provides a computer storage medium storing a computer program, which implements the steps of the method for first calibration of the power range of the RPN system after the material replacement is started provided in an embodiment of the present invention when the computer program is running.

[0076] like Figure 3 As shown, the present invention also provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for first calibration of the power range of the RPN system after material replacement is started provided in an embodiment of the present invention are implemented.

[0077] It can be understood that the technical solution of the present invention can calibrate the power range coefficient of each range measurement channel in a nuclear power unit without actively introducing xenon oscillations, replacing the current xenon oscillation test calibration method, avoiding the introduction of disturbances to the reactor, and reducing the risk of reactivity control. It has the advantages of high safety in the calibration process, short calibration time, and low radioactive waste liquid production rate, and plays a positive role in providing safety and economic benefits for nuclear power plants.

[0078] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0079] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0080] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0081] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A method for first calibration of the power range of an RPN system after starting a material change, characterized in that: include: During the first startup and power increase process of the nuclear power unit after refueling, the unit power is continuously monitored to obtain the corresponding in-core power and axial power data at each set power during the process of the unit power increasing from the first set power to the nth set power; wherein n is a natural number greater than 3; The coefficient of the RPN power range is determined according to the in-pile power and axial power data corresponding to the first set power to the nth set power.

2. The method for first calibration of the power range of the RPN system after starting the material change according to claim 1 is characterized in that: The axial power data includes an upper detector response current and a lower detector response current; The step of determining the coefficient of the RPN power range according to the axial power data and the in-stack power corresponding to the first set power to the nth set power comprises: Substitute the axial power data and the in-pile power corresponding to each set power into the set equation to obtain n sets of equations; Fitting the n sets of equations by the least square method to obtain coefficients of the RPN power range; Wherein, the setting equation is expressed as: W m Indicates the internal power of the stack corresponding to the mth set power, m = 1, 2, 3, ..., n, ΔI m represents the axial power deviation corresponding to the mth set power. The coefficients of the RPN power range include α, K U , K L , I U represents the upper detector response current, I L represents the lower detector response current.

3. The method for first calibration of the power range of the RPN system after starting the material change according to claim 1 or 2, characterized in that: The step of obtaining the in-pile power and axial power data corresponding to each set power also includes: Acquiring operating data of the nuclear power unit; Determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data; The acquisition of the in-core power and axial power data is allowed only when the operating condition of the nuclear power unit is stable at the corresponding set power.

4. The method for first calibration of the power range of the RPN system after starting the material change according to claim 3 is characterized in that: The n is equal to 4, and the first set power to the nth set power are respectively equal to 50% FP, 75% FP, 85% FP, and 100% FP.

5. The method for first calibration of the power range of the RPN system after starting the material change according to claim 4 is characterized in that: The operation data includes steam turbine control mode information, power control rod group position information, temperature control rod group position information, primary circuit pressure, reactor coolant average temperature and reactor coolant reference temperature; The step of determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data comprises: When the nuclear power unit is at the first set power or the third set power, determine whether the steam turbine is in the automatic load control mode according to the steam turbine control mode information, determine whether the power control rods in the power control rod group are in a completely core-extracted state according to the power control rod group position information, determine whether the primary loop pressure is within the set pressure range, determine whether the temperature control rod group is within the set adjustment band according to the temperature control rod group position information, and determine whether the difference between the reactor coolant average temperature and the reactor coolant reference temperature is less than the set temperature; When the steam turbine is in automatic load control mode, the power control rod is in a completely core-extracted state, the first-loop pressure is within a set pressure range, the temperature control rod group is within a set step range and the difference is less than a set temperature, it is determined that the operating condition of the nuclear power unit is stable at the corresponding set power.

6. The method for first calibration of the power range of the RPN system after starting the material change according to claim 5 is characterized in that: The operation data also includes power variation information, boron dilution record information and axial power deviation information; The step of determining whether the operating condition of the nuclear power unit at each set power is stable according to the operating data comprises: When the nuclear power unit is at the second set power or the fourth set power, determine whether the steam turbine is in the automatic load control mode according to the steam turbine control mode information, determine whether the power control rod is in a completely core-extracted state according to the power control rod group position information, determine whether the primary loop pressure is within the set pressure range, determine whether the temperature control rod group is within the set adjustment band according to the temperature control rod group position information, determine whether the number of steps of the single-direction continuous change of the rod position of the temperature control rod group within the first set time is greater than the set number of steps according to the temperature control rod group position information, determine whether the difference between the reactor coolant average temperature and the reactor coolant reference temperature is less than the set temperature, determine whether the time the nuclear power unit remains in the corresponding power range is greater than the corresponding time length according to the power change information, determine whether the nuclear power unit has performed a manual boron dilution operation within the second set time according to the boron dilution record information, and determine whether the change rate of the axial power deviation is less than the set power change rate according to the axial power deviation information; When the steam turbine is in automatic load control mode, the power control rod is in a state of being completely lifted out of the core, the primary circuit pressure is within the set pressure range, the temperature control rod group is within the set adjustment band range, the number of steps of continuous unidirectional change of the rod position of the temperature control rod group within the first set time is not greater than the set number of steps, the difference is less than the set temperature, the nuclear power unit remains within the corresponding power range for a time greater than the corresponding time length, the nuclear power unit has not performed manual boron dilution operation within the second set time and the change rate of the axial power deviation is less than the set power change rate, it is determined that the operating condition of the nuclear power unit is stable under the corresponding set power.

7. The method for first calibration of the power range of the RPN system after starting the material change according to claim 6 is characterized in that: When the nuclear power unit is at the second setting power, the corresponding power range is 73% FP to 77% FP, and the corresponding duration is 6 hours; When the nuclear power unit is at the 4th setting power, the corresponding power range is 98% FP to 102% FP, and the corresponding duration is 48 hours.

8. The method for first calibration of the power range of the RPN system after starting the material change according to claim 6 is characterized in that: The set pressure range is 153 bar.g to 154 bar.g, the set adjustment band range is between ±6 steps in the middle of the adjustment band, the set number of steps is 2 steps, the set temperature is 0.5°C, the first set time and the second set time are 6h, and the set power change rate is 0.3% FP / h.

9. A computer storage medium, characterized in that A computer program is stored, and when the computer program is run, the steps of the method for first calibration of the power range of the RPN system after the material change is started according to any one of claims 1 to 8 are implemented.

10. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for first calibration of the power range of the RPN system after the start of material replacement as described in any one of claims 1 to 8 are implemented.

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