A protection setting method and system for the first loading of a pressurized water reactor

Abstract

The present invention provides a method and system for setting protection for the initial fuel loading of a pressurized water reactor. The method includes: placing neutron detectors and determining whether their available number meets a first protection condition; determining whether the parameters of the core coolant meet a second protection condition; placing a neutron source and a preset number of fuel assemblies, and determining whether the instrument count rate of the neutron detectors meets a third protection condition; moving the already placed fuel assemblies and placing new fuel assemblies, and determining whether the instrument count rate or countdown rate of each neutron detector meets a fourth protection condition; loading the fuel assemblies in groups and recalibrating if the countdown rate does not meet the fourth protection condition, until the loading is completed. The present invention performs multiple protection settings during the initial fuel loading of a pressurized water reactor, which can ensure that the subcriticality of the reactor loading process always meets safety supervision requirements, ensure the safety and controllability of the entire loading process, and improve the core safety and personnel safety during the reactor loading process.

Description

Technical Field

[0001] The present invention relates to the technical field of pressurized water reactor nuclear power plant charging, and in particular to a protection setting method and system for the initial charging of a pressurized water reactor. Background Art

[0002] Pressurized water reactor (PWR) nuclear power plants are the world's mainstream nuclear power generation units. They utilize new fuel assemblies with a specific degree of uranium-35U enrichment. During the initial loading of the reactor, deep subcriticality of the core must be maintained to ensure both reactor safety and the safety of the loading personnel. Because the reactor control rods are not yet installed, the core is filled with a high concentration of boron-containing coolant, ensuring a keff (effective multiplication factor) below 0.85 when fully loaded.

[0003] During the process of loading new fuel into the reactor core, neutron detectors are typically used to monitor the reactor core's neutron flux rate to effectively control the changes in subcriticality caused by the continuous addition of new fuel assemblies and ensure that the first reactor core remains in a deep subcritical state. Currently, a common method uses neutron flux measurements from external nuclear instruments to calculate the reactor's doubling period or startup rate, thereby monitoring the reactor's subcriticality. Connected audible and visual alarms are then used to alert reactor loading personnel. This method of monitoring core subcriticality is relatively simple and lacks appropriate protection measures for abnormal situations that may occur during the reactor loading process. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the safety protection of the first loading of a pressurized water reactor in the prior art, thereby providing a protection setting method and system for the first loading of a pressurized water reactor, which can perform multiple protection settings during the first loading of a pressurized water reactor, ensure the safety and controllability of the entire loading process, and improve the core safety and personnel safety during the reactor loading process.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] In a first aspect, the present invention provides a method for setting up protection for the initial loading of a pressurized water reactor, comprising the following steps:

[0007] placing a plurality of pre-calibrated neutron detectors at preset positions in a pressurized water reactor core, and determining whether an available number of the neutron detectors satisfies a first protection condition;

[0008] If the first protection condition is met, determining whether the parameters of the core coolant meet the second protection condition;

[0009] If the second protection condition is satisfied, placing a first preset number of fuel assemblies including neutron sources in preset positions, obtaining an instrument count rate of the neutron detector and calculating a background count rate of the neutron detector, placing a second preset number of fuel assemblies in a preset order, and determining whether the instrument count rate of the neutron detector satisfies a third protection condition;

[0010] If the third protection condition is met, the fuel assemblies are moved according to a preset movement sequence and a new set of fuel assemblies are placed. After the meter count rate of the neutron detector stabilizes, a new set of fuel assemblies is placed again and the reciprocal count rate of the neutron detector is calculated. It is then determined whether the meter count rate or reciprocal count rate of each neutron detector meets the fourth protection condition.

[0011] If the fourth protection condition is met, new fuel assemblies are continuously loaded according to the preset loading requirements. If the fourth protection condition is not met, loading is suspended and the countdown rate is recalibrated before continuing loading until the core loading is completed.

[0012] The protection setting method for the initial fueling of a pressurized water reactor provided by an embodiment of the present invention sequentially determines whether the number of available neutron detectors, the parameters of the core coolant, the instrument count rate of the neutron detectors, and the countdown rate of the neutron detectors meet corresponding protection conditions during the initial fueling process, and calibrates the countdown rate of the fueling process in real time until the fueling is completed. The present invention performs multiple protection settings during the initial fueling of a pressurized water reactor, which can ensure that the subcriticality of the reactor fueling process always meets safety supervision requirements, ensure the safety and controllability of the entire fueling process, and improve the core safety and personnel safety during the reactor fueling process.

[0013] Optionally, the neutron detector includes: a third preset number of source range neutron detectors and a fourth preset number of temporary neutron detectors, the source range neutron detectors are arranged at symmetrical positions outside the core along the vertical symmetry line or horizontal symmetry line of the core, the temporary neutron detectors are arranged inside the core, and the positions of the temporary neutron detectors are determined according to the positions of the source range neutron detectors.

[0014] The present invention measures the number and energy of neutrons using neutron detectors. The reactor core is composed of nuclear fuel, moderator, coolant, and various structural materials. It is inevitable that some neutrons in the core are absorbed by non-fissile materials, while others leak out of the core. Even among the neutrons absorbed by the fissile materials, only a portion triggers fission and produces the next generation of neutrons; the remainder triggers capture reactions and produces no neutrons. Therefore, by counting the number of neutrons in the core using neutron detectors and adjusting the loading process, it is possible to ensure that the subcriticality of the core meets safety monitoring requirements during loading.

[0015] Optionally, satisfying the first protection condition includes: at least a fifth preset number of neutron detectors are available and at least a sixth preset number of source range neutron detectors are available; wherein, the fifth preset number is less than or equal to the sum of the third preset number and the fourth preset number; and the sixth preset number is less than or equal to the third preset number.

[0016] The present invention determines whether the current neutron detector configuration satisfies a first protection condition, thereby confirming that charging is currently possible. This is because reliable monitoring of the charging process is only possible if a certain number of neutron detectors are currently available. If the number of available neutron detectors does not meet the first protection condition, the refueling device is locked and an audible and visual alarm is issued.

[0017] Optionally, satisfying the second protection condition includes: the water temperature of the core coolant is within a preset water temperature range; the water level of the core coolant is higher than a preset water level value; and the boric acid concentration of the core coolant is higher than a preset concentration value.

[0018] The pressurized water reactor of the present invention uses desalted, boron-containing desalted water as the core coolant. Its water temperature parameters, water level parameters, and boron concentration will affect the safety of the loading process. Therefore, before the first loading begins, the loading safety is ensured by judging whether the relevant parameters of the coolant are within the required range, thereby setting a second protection condition. The water temperature is required to be within a preset water temperature range; the higher the water level, the safer the state, so the water level must be higher than the preset water level value; the higher the boric acid concentration, the safer the state, so the boric acid concentration must be higher than the preset concentration value. If any of the four signals of high or low water temperature, low water level, and low boric acid concentration is triggered, the operation of the material replacement device is locked and an audible and visual alarm is issued.

[0019] Optionally, the background count rate calculation process includes: counting each neutron detector for a preset number of times in a preset time period to obtain an instrument count rate; calculating an average value of the preset number of instrument count rates as the background count rate of the corresponding neutron detector;

[0020] The countdown count rate calculation process includes: obtaining the current instrument count rate of the neutron detector as a reference count rate after the counting is stabilized; obtaining the current instrument count rate of the neutron detector after loading a new fuel assembly according to preset loading requirements, and calculating the measured count rate based on the background count rate, wherein the measured count rate = instrument count rate - background count rate; and calculating the countdown count rate based on the reference count rate and the measured count rate, wherein the countdown count rate = reference count rate / measured count rate.

[0021] The process of recalibrating the countdown rate includes: obtaining the current instrument count rate of the neutron detector and calculating the measured count rate after calibration based on the background count rate; calculating a calibrated reference count rate based on the measured count rate after calibration, wherein the calibrated reference count rate = the measured count rate after calibration * the countdown rate before calibration; and calculating the calibrated countdown rate based on the calibrated reference count rate and the measured count rate after calibration.

[0022] This method calculates the neutron detector's background count rate and countdown rate based on the neutron counts by the sub-detectors during the loading process, and adjusts the countdown rate. Monitoring these various parameters is equivalent to monitoring the neutron count within the core, enabling full control of the initial loading process and meeting safety oversight requirements.

[0023] Optionally, satisfying the third protection condition includes: an increase multiple of the instrument count rate of any of the neutron detectors within a first preset time period is less than a first preset multiple value.

[0024] Prior to formal fuel loading, the present invention loads a preset number of fuel assemblies containing neutron sources and fuel assemblies without neutron sources. During this state, the neutron count within the core is monitored. If the neutron detector count rate increases by a preset multiple within a certain period of time, it indicates a sudden increase in the neutron count within the core, potentially making the loading process unsafe and uncontrollable. Therefore, a third protection condition is established. If the count rate of any neutron detector increases by a preset multiple within a preset period of time, the refueling device is shut down and an audible and visual alarm is sounded.

[0025] Optionally, satisfying the fourth protection condition includes: the increase multiple of the instrument counting rate of any of the neutron detectors within the second preset time period is less than the second preset multiple; and the increase multiple of the instrument counting rate of the seventh preset number of neutron detectors within the second preset time period is less than the third preset multiple, and the third preset multiple is less than the second preset multiple; and the countdown rate is greater than or equal to the preset threshold.

[0026] During the formal loading process, the present invention loads a group of fuel assemblies each time, and after each loading, the instrument count rate or countdown rate of the neutron detector is judged. If the increase multiple of the instrument count rate of any neutron detector reaches a higher preset multiple within a preset time period, or the increase multiple of the instrument count rate of a certain part of the neutron detectors reaches a lower preset multiple within a preset time period, or the countdown rate is less than a preset threshold, an audible and visual alarm is issued, requiring the loading personnel to suspend loading and recalibrate a new reference count rate. After calibrating the countdown rate, loading and judgment are continued until the core loading is completed. Parameter judgment for each loading can ensure that the entire first loading process is safe and controllable, and the subcriticality of the reactor loading process always meets the safety supervision requirements, thereby improving the core safety and personnel safety during the reactor loading process.

[0027] In a second aspect, an embodiment of the present invention provides a protection setting system for initial fuel loading of a pressurized water reactor, the system comprising:

[0028] a first protection module, configured to place a plurality of pre-calibrated neutron detectors at preset positions in a pressurized water reactor core and determine whether an available number of the neutron detectors satisfies a first protection condition;

[0029] a second protection module, configured to determine whether a parameter of a core coolant satisfies a second protection condition if the first protection condition is satisfied;

[0030] a third protection module, configured to, if the second protection condition is satisfied, place a first preset number of fuel assemblies containing neutron sources at preset positions, obtain an instrument count rate of the neutron detector and calculate a background count rate of the neutron detector, place a second preset number of fuel assemblies in a preset order, and determine whether the instrument count rate of the neutron detector satisfies the third protection condition;

[0031] a fourth protection module, configured to, if the third protection condition is met, move the fuel assembly according to a preset movement sequence and insert a new set of fuel assemblies, wait for the meter count rate of the neutron detector to stabilize before inserting another set of fuel assemblies, calculate the reciprocal count rate of the neutron detector, and determine whether the meter count rate or reciprocal count rate of each neutron detector meets the fourth protection condition;

[0032] The loading adjustment module is used to continue loading new fuel assemblies according to the preset loading requirements if the fourth protection condition is met; if the fourth protection condition is not met, suspend loading and recalibrate the countdown rate before continuing loading until the core loading is completed.

[0033] The protection setting system for the initial fueling of a pressurized water reactor provided by an embodiment of the present invention sequentially determines whether the number of available neutron detectors, the parameters of the core coolant, the instrument count rate of the neutron detectors, and the countdown rate of the neutron detectors meet corresponding protection conditions during the initial fueling process, and calibrates the countdown rate of the fueling process in real time until the fueling is completed. The present invention implements multiple protection settings during the initial fueling of a pressurized water reactor, which can ensure that the subcriticality of the reactor fueling process always meets safety supervision requirements, ensure the safety and controllability of the entire fueling process, and improve the core safety and personnel safety during the reactor fueling process.

[0034] In a third aspect, an embodiment of the present invention provides a computer device comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, computer instructions are stored in the memory, and the processor executes the method described in the first aspect or any optional embodiment of the first aspect by executing the computer instructions.

[0035] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method described in the first aspect or any optional implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A schematic flow chart of a method for setting up protection for initial loading of a pressurized water reactor provided by an embodiment of the present invention;

[0038] Figure 2 A schematic diagram of a core preset position for a protection setting method for initial loading of a pressurized water reactor provided by an embodiment of the present invention;

[0039] Figure 3 A schematic structural diagram of a protection system for initial fuel loading of a pressurized water reactor provided by an embodiment of the present invention;

[0040] Figure 4 A schematic structural diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0042] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] The embodiment of the present invention provides a protection setting method for the initial loading of a pressurized water reactor, such as Figure 1 As shown, the method specifically includes the following steps:

[0044] Step S1: placing a plurality of pre-calibrated neutron detectors at preset positions in a pressurized water reactor core, and determining whether the available number of the neutron detectors meets a first protection condition.

[0045] Specifically, in an embodiment of the present invention, two source range neutron detectors SR1 and SR2 and three temporary neutron detectors A, B and C are selected, but not limited to this. The five neutron detectors are calibrated, and after confirming that the detectors are normal and effective, each neutron detector is placed at a preset position in the pressurized water reactor core. The two source range neutron detectors are set at symmetrical positions outside the core along the vertical symmetry line or horizontal symmetry line of the core, and the temporary neutron detector is set inside the core, and the position of the temporary neutron detector is determined according to the position of the source range neutron detector. The position of the temporary neutron detector (A, B, C) relative to the source range neutron detector (SR1 or SR2) remains unchanged. In one embodiment, the specific placement position is as follows Figure 2 As shown, source range neutron detector SR1 of source 1 is placed at 90° outside the core, source range neutron detector SR2 of source 2 is placed at 270° outside the core, temporary neutron detector A is placed at position 0A in the core, temporary neutron detector B is placed at position 0B in the core, and temporary neutron detector C is placed at position 0C in the core.

[0046] In an embodiment of the present invention, a determination is made as to whether the number of available neutron detectors meets a first protection condition, wherein the first protection condition is: at least a fifth preset number of neutron detectors are available and at least a sixth preset number of source-range neutron detectors are available; wherein the fifth preset number is less than or equal to the sum of the third and fourth preset numbers; and the sixth preset number is less than or equal to the third preset number. For example, the next step can be performed only when at least three of the two source-range detectors and three temporary neutron detectors are available, and at least one source-range neutron detector must be available, but this is not a limitation. If the first protection condition is not met, the operation of the refueling device is locked and an audible and visual alarm is issued.

[0047] Step S2: If the first protection condition is met, determine whether the parameters of the core coolant meet the second protection condition.

[0048] Specifically, in an embodiment of the present invention, if the available number of neutron detectors meets the first protection condition, the parameters of the core coolant are judged. The pressurized water reactor uses desalted boron-containing desalted water as the core coolant. Its water temperature parameters, water level parameters and boron concentration will affect the safety of the loading process. Therefore, before the first loading begins, the loading safety is ensured by judging whether the relevant parameters of the coolant are within the required range. Therefore, the second protection condition is set: the water temperature of the core coolant is in the preset water temperature range; and the water level of the core coolant is higher than the preset water level value; and the boric acid concentration of the core coolant is higher than the preset concentration value. For example, the preset water temperature range is set to 10℃-50℃, and the boric acid concentration C B The range is 2300-2600ppm, but not limited thereto. Furthermore, there are no limits on high water levels or high boric acid concentrations, as higher water levels or higher boric acid concentrations indicate a safer state. Before loading, if any of the four signals—high or low water temperature, low water level, or low boric acid concentration—is triggered, the refueling system will be shut down and an audible and visual alarm will sound.

[0049] Step S3: If the second protection condition is met, a first preset number of fuel assemblies containing neutron sources are placed in preset positions, the instrument count rate of the neutron detector is obtained and the background count rate of the neutron detector is calculated, a second preset number of fuel assemblies are placed in a preset order, and it is determined whether the instrument count rate of the neutron detector meets the third protection condition.

[0050] Specifically, in an embodiment of the present invention, neutron detectors placed in the core measure neutron data within the core. The core is composed of nuclear fuel, moderator, coolant, and various structural materials. It's inevitable that some of the neutrons in the core will be absorbed by non-fissile materials, while others will leak out of the core. Even among the neutrons absorbed by fissile materials, only a portion will trigger fission and produce the next generation of neutrons; the remainder will trigger capture reactions and not produce neutrons. If the neutron count in the core can be controlled to remain stable, that is, the neutron production rate equals the neutron disappearance rate, the reactor can achieve a self-sustaining chain reaction, effectively reaching criticality. Therefore, during the loading process, the reactor must be kept in a subcritical state to prevent fission reactions. By counting the number of neutrons in the core using neutron detectors and adjusting the loading process, it is possible to ensure that the subcriticality of the core meets safety oversight requirements during loading.

[0051] In the embodiment of the present invention, if the parameters of the core coolant meet the second protection condition, the instrument count rate of each neutron detector is judged. Before this, it is necessary to first install two fuel assemblies containing neutron sources into the core at positions 1S and 2S according to the preset positions. The placement positions are as follows: Figure 2 As shown, but not limited to, the neutron source is placed to increase the neutron fluence rate during reactor startup. At this point, the instrument count rates of the five neutron detectors—source range neutron detectors SR1 and SR2 and temporary neutron detectors A, B, and C—are acquired, and their background count rates are calculated.

[0052] Among them, the calculation process of background count rate is:

[0053] 1. Count each neutron detector a preset number of times for a preset time period to obtain an instrument count rate;

[0054] 2. Calculate the average value of the instrument count rate for a preset number of times as the background count rate of the corresponding neutron detector.

[0055] For example, the present invention selects to count the instrument of any neutron detector three times for 100 seconds, and uses the average value of the three counts as the background count rate N0 of the corresponding neutron detector.

[0056] Next, a preset number of fuel assemblies are placed in the corresponding positions in a preset order. Specifically, as shown in Figure 2, six fuel assemblies are placed in positions 3-7 and position 8A, but this is not a limitation. At this point, a determination is made as to whether the instrument count rate of the neutron detectors meets the third protection condition, where the third protection condition is that the increase in the instrument count rate of any of the neutron detectors within the first preset time period is less than the first preset multiple value. For example, the present invention selects a first preset multiple of 3 and a preset time period of 100 seconds, but this is not a limitation. If the count rate of any of the five neutron detectors, including source range neutron detectors SR1 and SR2 and temporary neutron detectors A, B, and C, increases by 3 times within 100 seconds, the refueling device is locked and an audible and visual alarm is issued.

[0057] Step S4: If the third protection condition is met, the fuel assembly is moved according to the preset movement order, and a new set of fuel assemblies is placed. After the instrument count rate of the neutron detector stabilizes, another new set of fuel assemblies is placed and the reciprocal count rate of the neutron detector is calculated, and it is determined whether the instrument count rate or reciprocal count rate of each neutron detector meets the fourth protection condition.

[0058] Specifically, in the embodiment of the present invention, if the number of times the instrument count rate of the neutron detector increases within a preset time period satisfies the third protection condition, the countdown rate of each neutron detector is judged during the loading process. Prior to this, the fuel assembly at position 8A and the fuel assembly containing the neutron source need to be moved according to the preset movement sequence. Figure 2 As shown, move the fuel assembly from 8A to Figure 2 8B position, neutron source No. 1 moves from 1S to Figure 2 8A position, the No. 2 neutron source moved from 2S to Figure 2 1S position, in Figure 2 A new set of fuel assemblies is placed at the 2S position of the neutron detector. After the meter count rate of each neutron detector is stable, the current meter count rate of each neutron detector is obtained as the reference count rate. In the embodiment of the present invention, the counts of SR2, B, and C are selected as the reference count rate because the fuel is loaded from Figure 2 The fuel assembly is then loaded to the right of the neutron detector, near SR2, B, and C. A new set of fuel assemblies is then added according to the loading requirements. The instrument count rate of the neutron detector at this time is obtained and the measured count rate of the neutron detector at this time is calculated. The calculation formula for the measured count rate is:

[0059] Measured counting rate = instrument counting rate - background counting rate N0

[0060] The countdown rate CR is calculated based on the reference count rate and the measured count rate. The calculation formula is:

[0061]

[0062] Finally, it is determined whether the meter count rate or countdown rate of each neutron detector meets the fourth protection condition. The fourth protection condition is: the meter count rate of any of the neutron detectors increases by less than the second preset multiple within the second preset time period, and the meter count rate of the seventh preset number of neutron detectors increases by less than the third preset multiple within the second preset time period, the third preset multiple is less than the second preset multiple, and the countdown rate is greater than or equal to a preset threshold. For example, the present invention selects the second preset time period as 100 seconds, the second preset multiple as 4 times, the third preset multiple as 2 times, and the preset threshold as 0.15, but is not limited to this. If the count rate of any of the five neutron detectors increases by 4 times within 100 seconds, or if the count rates of any four detectors double within 100 seconds, the operation of the refueling device is shut down and an audible and visual alarm is issued. If the countdown rate is less than 0.15, an audible and visual alarm is issued, loading is suspended, and a new reference count rate is re-determined.

[0063] Step S5: If the fourth protection condition is met, new fuel assemblies are continuously loaded according to the preset loading requirements. If the fourth protection condition is not met, loading is suspended and the countdown rate is recalibrated before continuing loading until the core loading is completed.

[0064] Specifically, in an embodiment of the present invention, if the countdown rate of the neutron detector does not meet the fourth protection condition, the countdown rate is recalibrated, and the process is as follows:

[0065] 1. Obtain the current neutron detector instrument count rate and calculate the measured count rate after calibration based on the background count rate;

[0066] 2. Calculate the reference count rate after calibration based on the measured count rate after calibration. The calculation formula is:

[0067] Reference counting rate after calibration = measured counting rate after calibration * countdown rate before calibration

[0068] 3. Calculate the calibrated countdown rate based on the calibrated reference count rate and the calibrated measured count rate.

[0069] In the embodiment of the present invention, after recalibrating the countdown rate, the loading process continues, with one group of fuel assemblies loaded at a time. After each loading, the instrument count rate and countdown rate of the neutron detector are judged until the core loading is completed. The pressurized water reactor core selected by the present invention requires a total of 155 groups of fuel assemblies to be placed, and the placement positions are as follows: Figure 2 The core grid shown is, but not limited to.

[0070] The protection setting method for the initial fueling of a pressurized water reactor provided by an embodiment of the present invention sequentially determines whether the number of available neutron detectors, the parameters of the core coolant, the instrument count rate of the neutron detectors, and the countdown rate of the neutron detectors meet corresponding protection conditions during the initial fueling process, and calibrates the countdown rate of the fueling process in real time until the fueling is completed. The present invention performs multiple protection settings during the initial fueling of a pressurized water reactor, which can ensure that the subcriticality of the reactor fueling process always meets safety supervision requirements, ensure the safety and controllability of the entire fueling process, and improve the core safety and personnel safety during the reactor fueling process.

[0071] The embodiment of the present invention provides a protection setting system for the initial loading of a pressurized water reactor, such as Figure 3 As shown, the system includes:

[0072] The first protection module 1 is configured to place a plurality of pre-calibrated neutron detectors at predetermined locations within the pressurized water reactor core and determine whether the number of available neutron detectors satisfies a first protection condition. For details, see the description of step S1 in the above method embodiment and will not be repeated here.

[0073] The second protection module 2 is configured to determine whether the core coolant parameters meet the second protection condition if the first protection condition is met. For details, please refer to the description of step S2 in the above method embodiment, which will not be repeated here.

[0074] The third protection module 3 is configured to, if the second protection condition is met, place a first preset number of fuel assemblies containing neutron sources in preset positions, obtain the meter count rate of the neutron detector and calculate the background count rate of the neutron detector, place a second preset number of fuel assemblies in a preset order, and determine whether the meter count rate of the neutron detector meets the third protection condition. For details, see the description of step S3 in the above method embodiment and will not be repeated here.

[0075] The fourth protection module 4 is configured to, if the third protection condition is met, move the fuel assemblies according to a preset movement sequence and insert a new set of fuel assemblies. After the meter count rates of the neutron detectors stabilize, another set of fuel assemblies is inserted, calculate the reciprocal count rates of the neutron detectors, and determine whether the meter count rates or reciprocal count rates of each neutron detector meet the fourth protection condition. For details, see the description of step S4 in the above method embodiment and will not be repeated here.

[0076] The loading adjustment module 5 is configured to continue loading new fuel assemblies according to the preset loading requirements if the fourth protection condition is met. If the fourth protection condition is not met, loading is suspended and the countdown rate is recalibrated before continuing loading until the core is loaded. For details, see the description of step S5 in the above method embodiment and will not be repeated here.

[0077] The protection setting system for the initial fueling of a pressurized water reactor provided by an embodiment of the present invention sequentially determines whether the number of available neutron detectors, the parameters of the core coolant, the instrument count rate of the neutron detectors, and the countdown rate of the neutron detectors meet corresponding protection conditions during the initial fueling process, and calibrates the countdown rate of the fueling process in real time until the fueling is completed. The present invention implements multiple protection settings during the initial fueling of a pressurized water reactor, which can ensure that the subcriticality of the reactor fueling process always meets safety supervision requirements, ensure the safety and controllability of the entire fueling process, and improve the core safety and personnel safety during the reactor fueling process.

[0078] Figure 4 FIG. 1 shows a schematic diagram of the structure of a computer device according to an embodiment of the present invention, including a processor 901 and a memory 902 , wherein the processor 901 and the memory 902 may be connected via a bus or other means. Figure 4 The bus connection is taken as an example.

[0079] The processor 901 may be a central processing unit (CPU). The processor 901 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0080] Memory 902, as a non-transitory computer-readable storage medium, can be used to store non-transitory server programs, non-transitory computer executable programs, and modules, such as the program instructions / modules corresponding to the methods in the above-described method embodiments. Processor 901 executes the non-transitory server programs, instructions, and modules stored in memory 902 to perform various processor functions and data processing, thereby implementing the methods in the above-described method embodiments.

[0081] The memory 902 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created by the processor 901, etc. In addition, the memory 902 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 902 may optionally include a memory remotely located relative to the processor 901, and these remote memories may be connected to the processor 901 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0082] One or more modules are stored in the memory 902 and, when executed by the processor 901 , perform the method in the above method embodiment.

[0083] The specific details of the above-mentioned computer device can be understood by referring to the corresponding descriptions and effects in the above-mentioned method embodiments, and will not be repeated here.

[0084] Those skilled in the art will appreciate that all or part of the processes in the above-described embodiments can be implemented by instructing related hardware through a computer program. The implemented program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-described embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD). The storage medium can also include a combination of the above-mentioned types of memory.

[0085] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A protection setting method for the initial loading of a pressurized water reactor, characterized in that: The steps include: placing a plurality of pre-calibrated neutron detectors at preset positions in a pressurized water reactor core, and determining whether an available number of the neutron detectors satisfies a first protection condition; If the first protection condition is met, determining whether the parameters of the core coolant meet the second protection condition; If the second protection condition is satisfied, placing a first preset number of fuel assemblies including neutron sources in preset positions, obtaining an instrument count rate of the neutron detector and calculating a background count rate of the neutron detector, placing a second preset number of fuel assemblies in a preset order, and determining whether the instrument count rate of the neutron detector satisfies a third protection condition; If the third protection condition is met, the fuel assemblies are moved according to a preset movement sequence and a new set of fuel assemblies are placed. After the meter count rate of the neutron detector stabilizes, a new set of fuel assemblies is placed again and the countdown rate of the neutron detector is calculated. It is then determined whether the meter count rate and countdown rate of each neutron detector meet the fourth protection condition. If the fourth protection condition is met, new fuel assemblies are continuously loaded according to the preset loading requirements; if the fourth protection condition is not met, loading is suspended and the countdown rate is recalibrated before continuing loading until the core loading is completed; The neutron detectors include: a third preset number of source range neutron detectors and a fourth preset number of temporary neutron detectors, wherein the source range neutron detectors are arranged at symmetrical positions outside the core along a vertical symmetry line or a horizontal symmetry line of the core, and the temporary neutron detectors are arranged inside the core, and the positions of the temporary neutron detectors are determined according to the positions of the source range neutron detectors; The first protection condition being satisfied includes: At least a fifth predetermined number of neutron detectors are available and at least a sixth predetermined number of source range neutron detectors are available; The fifth preset number is less than or equal to the sum of the third preset number and the fourth preset number; the sixth preset number is less than or equal to the third preset number; The satisfying of the second protection condition includes: The water temperature of the core coolant is within a preset water temperature range; and the water level of the core coolant is higher than a preset water level value; and the boric acid concentration of the core coolant is higher than a preset concentration value; The third protection condition is satisfied, including: the increase multiple of the instrument count rate of any neutron detector within the first preset time period is less than the first preset multiple value; The fourth protection condition is satisfied, including: The increase multiple of the instrument count rate of any of the neutron detectors within the second preset time period is less than the second preset multiple; and the instrument count rate of the seventh preset number of neutron detectors increases by a multiple smaller than a third preset multiple within the second preset time period, and the third preset multiple is smaller than the second preset multiple; And the countdown rate is greater than or equal to a preset threshold.

2. The protection setting method for the initial charging of a pressurized water reactor according to claim 1, characterized in that: The calculation process of the background count rate includes: Counting each of the neutron detectors for a preset number of times and a preset time period to obtain an instrument count rate; Calculating an average value of the instrument count rate for a preset number of times as the corresponding background count rate of the neutron detector; The calculation process of the countdown rate includes: After the counting is stable, obtaining the current instrument counting rate of the neutron detector as a reference counting rate; After loading a new fuel assembly according to preset loading requirements, obtaining the current instrument count rate of the neutron detector, and calculating the measured count rate based on the background count rate, wherein the measured count rate = instrument count rate - background count rate; Calculate the countdown rate according to the reference count rate and the measured count rate, wherein the countdown rate = reference count rate / measured count rate; The process of recalibrating the countdown rate includes: Obtaining the current instrument count rate of the neutron detector and calculating the calibrated measured count rate based on the background count rate; Calculate the reference count rate after calibration according to the measured count rate after calibration, wherein the reference count rate after calibration = the measured count rate after calibration * the countdown rate before calibration; The calibrated countdown rate is calculated based on the calibrated reference count rate and the calibrated measured count rate.

3. A protection system for the initial loading of a pressurized water reactor, characterized in that: include: a first protection module, configured to place a plurality of pre-calibrated neutron detectors at preset positions in a pressurized water reactor core and determine whether an available number of the neutron detectors satisfies a first protection condition; a second protection module, configured to determine whether a parameter of a core coolant satisfies a second protection condition if the first protection condition is satisfied; a third protection module, configured to, if the second protection condition is satisfied, place a first preset number of fuel assemblies containing neutron sources at preset positions, obtain an instrument count rate of the neutron detector and calculate a background count rate of the neutron detector, place a second preset number of fuel assemblies in a preset order, and determine whether the instrument count rate of the neutron detector satisfies the third protection condition; a fourth protection module, configured to, if the third protection condition is met, move the fuel assembly according to a preset movement sequence and insert a new set of fuel assemblies, wait for the meter count rate of the neutron detector to stabilize before inserting another set of fuel assemblies, calculate the countdown rate of the neutron detector, and determine whether the meter count rate and countdown rate of each neutron detector meet the fourth protection condition; a loading adjustment module, configured to continue loading new fuel assemblies according to preset loading requirements if the fourth protection condition is met, and to suspend loading and recalibrate the countdown rate before continuing loading until core loading is completed if the fourth protection condition is not met; The neutron detectors include: a third preset number of source range neutron detectors and a fourth preset number of temporary neutron detectors, wherein the source range neutron detectors are arranged at symmetrical positions outside the core along a vertical symmetry line or a horizontal symmetry line of the core, and the temporary neutron detectors are arranged inside the core, and the positions of the temporary neutron detectors are determined according to the positions of the source range neutron detectors; The first protection condition being satisfied includes: At least a fifth predetermined number of neutron detectors are available and at least a sixth predetermined number of source range neutron detectors are available; The fifth preset number is less than or equal to the sum of the third preset number and the fourth preset number; the sixth preset number is less than or equal to the third preset number; The satisfying of the second protection condition includes: The water temperature of the core coolant is within a preset water temperature range; and the water level of the core coolant is higher than a preset water level value; and the boric acid concentration of the core coolant is higher than a preset concentration value; The third protection condition is satisfied, including: the increase multiple of the instrument count rate of any neutron detector within the first preset time period is less than the first preset multiple value; The fourth protection condition is satisfied, including: The increase multiple of the instrument count rate of any of the neutron detectors within the second preset time period is less than the second preset multiple; and the instrument count rate of the seventh preset number of neutron detectors increases by a multiple smaller than a third preset multiple within the second preset time period, and the third preset multiple is smaller than the second preset multiple; And the countdown rate is greater than or equal to a preset threshold.

4. An electronic device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the protection setting method for the initial loading of a pressurized water reactor according to any one of claims 1 to 2 by executing the computer instructions.

5. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the protection setting method for the initial loading of a pressurized water reactor according to any one of claims 1 to 2.

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