Method and system for irradiation management of fuel assemblies in a nuclear power plant

Abstract

The present application relates to a kind of nuclear power plant fuel assembly irradiation management method and system, its method includes: determining the operation period where unit is located;Wherein, the unit state includes normal operation period, monitoring period before overhaul, monitoring period after overhaul and abnormal period;According to the operation period where unit is located, determine data sampling strategy;According to the data sampling strategy, obtain radiochemical data;Determine the specific activity interval where the radiochemical data is located;Based on the specific activity interval where the radiochemical data is located, output operation instruction for avoiding specific activity anomaly.The present application can make fuel assembly work in suitable irradiation environment, can effectively avoid specific activity anomaly condition in primary loop, improve the safety of nuclear power plant.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant technology, and in particular to a method and system for managing the irradiation of fuel assemblies in nuclear power plants. Background Technology

[0002] During the operation of a nuclear power plant, the cleanliness of the primary loop system is a critical factor in ensuring the safe operation of the plant. However, due to deficiencies in radiochemical data monitoring methods, some nuclear power plants fail to detect anomalies in radiochemical data in a timely manner. Abnormal irradiation can affect the normal operation of fuel assemblies, potentially triggering a series of safety incidents, such as abnormal primary loop radiochemical parameters, thus impacting the safe operation of the nuclear power plant. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for managing the irradiation of fuel assemblies in nuclear power plants.

[0004] The technical solution adopted by this invention to solve its technical problem is: constructing a method for managing the irradiation of fuel assemblies in a nuclear power plant, comprising: Determine the operating period of the unit; wherein, the unit status includes the normal operation period, the pre-overhaul monitoring period, the post-overhaul monitoring period, and the abnormal period; The data sampling strategy is determined based on the operating period of the unit. Acquire radiometric data according to the data sampling strategy described above; Determine the specific activity range of the radiochemical data; Based on the specific activity range of the radiochemical data, an operating instruction is output to avoid abnormal specific activity.

[0005] Preferably, the normal operation period includes the period during which the unit operates at normal power and during normal power increase and decrease; the post-overhaul monitoring period is from the start-up of the unit after the overhaul to the first set time after the first full power; the pre-overhaul monitoring period is from the second set time before the overhaul to the start time of the overhaul; and the abnormal period is from the time when the unit abnormality is discovered to the time when the unit abnormality is eliminated. The step of determining the data sampling strategy based on the unit status includes: When the unit is in the normal operation period, the data sampling strategy is set to the first data sampling strategy; the first data sampling strategy includes: sampling radiochemical data N1 times a day after entering the normal operation period each time until the unit power is stable and continues for a third set time, and sampling radiochemical data N2 times a week after the unit power is stable and continues for the third set time. When the unit is in the pre-overhaul monitoring period, the data sampling strategy is set to the second data sampling strategy; the second data sampling strategy includes: sampling radiochemical data N3 times a day, and continuously sampling radiochemical data N4 times at a set frequency after the unit is shut down. When the unit is in the post-overhaul monitoring period, the data sampling strategy is set to the third data sampling strategy; the third data sampling strategy includes: sampling radiochemical data N5 times per day; When the unit is in the abnormal period, the data sampling strategy is set to the fourth data sampling strategy; the fourth data sampling strategy includes: when the unit abnormality will cause abnormal changes in the unit power, the number of sampling times of radiochemical data is increased by N6 times within a fourth set time after the abnormal change in the unit power.

[0006] Preferably, the first set time is 1 month, the third set time is 7 days, and the fourth set time is 24 hours; And / or, N1= N3= N5= N6=1, N2=2, N4=6, the set frequency is once per hour.

[0007] Preferably, the radiochemical data includes the specific activities of iodine radioisotopes and inert gases; Determining the specific activity range of the radiochemical data includes: When the specific activity of the iodine radioisotope in the radiochemical data is less than A1 and the specific activity of the inert gas is less than A2, the radiochemical data is determined to be in the first specific activity range. When the specific activity of the iodine radioisotope in the radiochemical data is less than A3 and greater than or equal to A1, and the specific activity of the inert gas is less than A4 and greater than or equal to A2, the radiochemical data is determined to be in the second specific activity range. When the specific activity of the iodine radioisotope in the radiochemical data is less than A5 and greater than or equal to A3, and the specific activity of the inert gas is less than A6 and greater than or equal to A4, the radiochemical data is determined to be in the third specific activity range. When the specific activity of the iodine radioisotope in the radiochemical data is greater than or equal to A5, and the specific activity of the inert gas is greater than or equal to A6, the radiochemical data is determined to be in the fourth specific activity range.

[0008] Preferably, the step of outputting operating instructions to avoid specific activity anomalies based on the specific activity range of the radiochemical data includes: When the radiochemical data is within the first specific activity range, a first operating instruction is output; wherein, the first operating instruction is used to control the unit to increase or decrease power through a dilution boronization strategy, and to limit the rate of increase or decrease of power within a set rate; When the radiochemical data is within the second specific activity range, a second operating instruction is output. After the second operating instruction is output, the changes in the radiochemical data are monitored. When the radiochemical data cannot recover to a smaller specific activity range within a fifth set time, a fifth operating instruction is output. The second operating instruction is used to prohibit the unit from performing load tracking and power increase / decrease. The fifth operating instruction is used to control the operation of the nuclear power plant's rod control system and boronizing system, so that the unit's reactivity drops below a set threshold and the reactor coolant average temperature drops below a set temperature within a seventh set time. When the radiochemical data is within the third specific activity range, a third operating instruction is output; after the third operating instruction is output, the change of the radiochemical data is monitored, and when the radiochemical data cannot recover to a smaller specific activity range within the fifth set time, the fifth operating instruction is output; wherein, the third operating instruction is used to achieve at least one of the following controls: controlling the main loop water to be discharged into the boron recovery system, controlling the volumetric control box in the chemical and volumetric control system to scaveng the exhaust gas treatment system, and controlling the desalination bed in the chemical and volumetric control system to maintain the maximum purification flow rate; When the radiochemical data is within the fourth specific activity range, a fourth operating instruction is output; after the fourth operating instruction is output, the changes in the radiochemical data are monitored, and when the radiochemical data cannot recover to a smaller specific activity range within an eighth set time, a sixth operating instruction is output to further reduce the unit power; wherein, the fourth operating instruction is used to control the unit to reduce power.

[0009] Preferably, the nuclear power plant fuel assembly irradiation management method further includes: Adjusting the data sampling strategy based on the specific activity range of the radiochemical data includes: When the radiochemical data is within the first specific activity range, a specific activity curve is fitted based on the radiochemical data acquired during the period, and it is determined whether the specific activity is trending upward based on the specific activity curve; when the specific activity is trending upward, it is determined whether the increase in the specific activity curve is greater than a first set percentage; when the increase in the specific activity curve is greater than the first set percentage, radiochemical data is sampled N7 times per day. When the radiochemical data is within the second specific activity range, N8 radiochemical data samples are taken daily. When the radiochemical data is within the third specific activity range, N9 radiochemical data samples are taken daily. When the radiochemical data is within the second specific activity range or the third specific activity range, the unit's load change parameters are also acquired; based on the load change parameters, it is determined whether the load change amplitude is greater than a second set percentage; when the load change amplitude is greater than the second set percentage, it is determined whether the duration of the load change amplitude being greater than the second set percentage is greater than a sixth set time; when the duration is greater than the sixth set time, N is added to the radiochemical data within the time interval T1 to T2. 10 Second sampling.

[0010] Preferably, the first set percentage is 20%, and the second set percentage is 15%. And / or, N7 = N8 = N 10 =1, N9=3, T1=2, T2=6.

[0011] Preferably, the nuclear power plant fuel assembly irradiation management method further includes: The first image is obtained by capturing images of the preset checkpoint before the start of the overhaul. During the overhaul, a foreign object barrier is installed around the steam generator to prevent foreign objects from entering the steam generator. The second image is obtained by capturing images of the preset checkpoint after the overhaul is completed. The extent of foreign object loss is determined based on the first and second captured images.

[0012] Preferably, the nuclear power plant fuel assembly irradiation management method further includes: During the overhaul, parameters to be tested for the fuel assembly are acquired; these parameters include information on residual foreign matter on the surface, weight changes, and positional offsets. The abnormal condition of the fuel assembly is determined based on the parameters to be detected.

[0013] The present invention also constructs a nuclear power plant fuel assembly irradiation management system, comprising: The operation period determination unit is used to determine the operation period of the unit; wherein, the unit status includes normal operation period, pre-overhaul monitoring period, post-overhaul monitoring period, and abnormal period; The strategy determination unit is used to determine the data sampling strategy based on the operating period of the unit; The data acquisition unit is used to acquire radiometric data according to the data sampling strategy; An interval determination unit is used to determine the specific activity interval in which the radiochemical data is located; The instruction generation unit is used to output an operation instruction to avoid specific activity abnormalities based on the specific activity range of the radiochemical data.

[0014] The technical solution of this invention collects radiochemical data through a rationally formulated strategy and outputs operating instructions based on the radiochemical data to adjust the working state of the unit, so that the fuel assembly works in a suitable irradiation environment, which can effectively avoid abnormal specific activity in the primary loop and improve the safety of nuclear power plants. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a flowchart illustrating the nuclear power plant fuel assembly irradiation management method in some embodiments of the present invention; Figure 2 This is a schematic diagram of the structure of a nuclear power plant fuel assembly irradiation management system in some embodiments of the present invention. Detailed Implementation

[0016] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] It should be noted that the flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0018] 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 can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0019] Figure 1 This is a flowchart illustrating a nuclear power plant fuel assembly irradiation management method in some embodiments of the present invention. This method collects radiochemical data using a rationally formulated strategy and outputs operational instructions based on the data to adjust the unit's operating status, ensuring the fuel assemblies operate under suitable irradiation conditions. This effectively prevents abnormal specific activity in the primary loop and improves the safety of the nuclear power plant.

[0020] In some embodiments, such as Figure 1 As shown, the nuclear power plant fuel assembly irradiation management method may include steps S10, S20, S30, S40 and S50.

[0021] Step S10 includes: determining the operating period of the unit. The unit status includes the normal operation period, the pre-overhaul monitoring period, the post-overhaul monitoring period, and the abnormal period.

[0022] In some embodiments, the normal operation period may include the period during which the unit operates at normal power and during normal power ramp-up and ramp-down. The post-overhaul monitoring period extends from the unit's restart after an overhaul to a first set time after the first full-power operation, where the first set time can be one month. The pre-overhaul monitoring period extends from a second set time before the overhaul to the start of the overhaul, where the second set time can be one month; that is, one month before the overhaul and the start of the overhaul are both defined as the pre-overhaul monitoring period. The abnormal period extends from the time the unit abnormality is detected to the time the abnormality is eliminated. It should be noted that grid load abnormalities or equipment abnormalities may both trigger unit abnormalities, and the time span of the abnormal period corresponds to the time period from the detection of the abnormality to its disappearance, which is variable. The abnormal period is usually encompassed between the end of the pre-overhaul monitoring period and the start of the pre-overhaul monitoring period, and multiple unit abnormalities may occur during this period, each generating an abnormal period. In other words, the normal operation period may include the time period from the end of the pre-overhaul monitoring period to the start of the pre-overhaul monitoring period, excluding all abnormal periods.

[0023] Furthermore, in some embodiments, step S10 may further include: Step S20 includes: determining the data sampling strategy based on the operating period of the unit.

[0024] In some embodiments, step S20 may include steps S201 to S204.

[0025] Step S201 includes: when the unit is in normal operation period, setting the data sampling strategy to the first data sampling strategy; the first data sampling strategy includes: sampling N1 radiochemical data every day after entering normal operation period until the unit power is stable and continues for a third set time, and sampling N2 radiochemical data every week after the unit power is stable and continues for a third set time.

[0026] In some embodiments, N1 can be equal to 1, the third set time can be 7 days, and N2 can be equal to 2. Understandably, after entering the normal operation period, it means that the unit's operating conditions are gradually stabilizing. To ensure safety, radiochemical data is sampled once a day when the normal operation period begins (which is a relatively high sampling frequency). When the unit's power is stable and the stable state can be maintained for 7 days, the sampling frequency of radiochemical data can be reduced to twice a week to avoid consuming a lot of manpower and resources due to the high sampling frequency.

[0027] Furthermore, the stability of the unit's power can be determined by the following method: judging whether the power deviation between the actual power and the target power of the unit exceeds the set deviation range (such as -1% to 1%). If so, the unit is determined to be in a stable state; otherwise, the unit is determined to be in an unstable state.

[0028] Step S202 includes: when the unit is in the pre-overhaul monitoring period, the data sampling strategy is set to the second data sampling strategy; the second data sampling strategy includes: sampling N3 radiochemical data per day, and continuously sampling N4 radiochemical data at a set frequency after the unit is shut down.

[0029] In some embodiments, N3 can be equal to 1, N4 can be equal to 6, and the set frequency can be once per hour. Understandably, since the reactor needs to be shut down before a major overhaul, it will cause significant power fluctuations. During this process, nuclear power plant equipment needs to trigger a series of safety protection measures, which may cause radiation fluctuations. Therefore, after entering the pre-overhaul monitoring period, it is necessary to increase the sampling frequency of radiochemical data in order to perform relevant operations and thus minimize the occurrence of specific activity anomalies during the shutdown process.

[0030] Step S203 includes: when the unit is in the post-overhaul monitoring period, the data sampling strategy is set to the third data sampling strategy; the third data sampling strategy includes: sampling radiochemical data N5 times a day.

[0031] In some embodiments, N5 can be equal to 1. Understandably, the risk of power fluctuations during the first startup of a unit after a major overhaul is relatively high, and the maintenance work on nuclear power plant equipment during the overhaul may also affect the operational stability of the equipment and cause abnormal situations (there is a risk of equipment abnormalities caused by human error during the maintenance process). Therefore, the sampling frequency of radiochemical data is relatively high compared to the normal operation period.

[0032] Step S204 includes: when the unit is in an abnormal period, setting the data sampling strategy to the fourth data sampling strategy; the fourth data sampling strategy includes: when the unit abnormality will cause abnormal changes in the unit power, increasing the number of radiochemical data sampling times by N6 times within a fourth set time after the abnormal changes in the unit power.

[0033] In some embodiments, the fourth set time can be 24 hours, and N6 can be equal to 1. Understandably, when an abnormal power change is detected in the unit, this embodiment will increase the sampling frequency of radiochemical data by one within the most recent 24 hours after the abnormal power change occurs, so that staff are aware of whether the unit power has exceeded the limit and can assist staff in handling the anomaly as quickly as possible. Further, whether an abnormal power change has occurred in the unit can be determined by: judging whether the rate of change (absolute value) of the unit power is greater than a set rate (which can be equal to 3MW / min); if so, it is determined that an abnormal power change has occurred in the unit.

[0034] Step S30 includes: acquiring radiochemical data according to a data sampling strategy. The radiochemical data may include the specific activity of iodine radioisotopes and the specific activity of inert gases.

[0035] Step S40 includes: determining the specific activity range in which the radiochemical data is located.

[0036] In some embodiments, step S40 may include steps S401 to S404.

[0037] Step S401 includes: when the specific activity of the iodine radioisotope in the radiochemical data is less than A1 and the specific activity of the inert gas is less than A2, the radiochemical data is determined to be in the first specific activity range. Here, A1 can be equal to 4.4 × 10⁻⁶. 3 MBq / t, A2 can be equal to 3.7 × 10 5 MBq / t.

[0038] Step S402 includes: when the specific activity of the iodine radioisotope in the radiochemical data is less than A3 but greater than or equal to A1, and the specific activity of the inert gas is less than A4 but greater than or equal to A2, the radiochemical data is determined to be in the second specific activity range. Here, A3 can be equal to 9.25 × 10⁻⁶. 3 MBq / t, A4 can be equal to 7.4 × 10 5 MBq / t.

[0039] Step S403 includes: when the specific activity of the iodine radioisotope in the radiochemical data is less than A5 but greater than or equal to A3, and the specific activity of the inert gas is less than A6 but greater than or equal to A4, the radiochemical data is determined to be in the third specific activity range. Here, A5 can be equal to 3.7 × 10⁻⁶. 4 MBq / t, A6 can be equal to 2.96 × 10 6 MBq / t.

[0040] Step S404 includes: when the specific activity of the iodine radioisotope in the radiochemical data is greater than or equal to A5 and the specific activity of the inert gas is greater than or equal to A6, the radiochemical data is determined to be in the fourth specific activity range.

[0041] Step S50 includes: outputting operating instructions to avoid abnormal specific activity based on the specific activity range of the radiochemical data. The operating instructions may include the first to fifth operating instructions, which adjust the unit operating conditions to restore the specific activity of the primary loop to normal as soon as possible, thereby avoiding excessive radioactive material content and leakage.

[0042] In some embodiments, step S50 may include steps S501 to S504.

[0043] Step S501 includes: when the radiochemical data is within a first specific activity range, outputting a first operating command. The first operating command is used to control the unit to preferentially increase or decrease power through a dilution boration strategy, and to limit the rate of increase or decrease in power within a set rate. Understandably, the purpose of the first operating command is to prevent significant increases or decreases in unit power. Since specific activity is closely related to reactivity, this helps to minimize the possibility of a surge in specific activity.

[0044] Step S502 includes: when the radiochemical data is in the second specific activity range, outputting a second operating command; after the second operating command is output, monitoring the changes in the radiochemical data, and when the radiochemical data cannot recover to a smaller specific activity range within a fifth set time, outputting a fifth operating command. The second operating command is used to prohibit the unit from performing load tracking and power increases / decreases, stabilizing the unit at the current power level. This prevents xenon oscillations and power peaks, thus avoiding power distortion and effectively suppressing the continued increase in the specific activity of iodine radioisotopes and inert gases. Typically, it allows the radiochemical data to recover from the second specific activity range to the first specific activity range within the fifth set time (which can be 48 hours). The fifth operating command is used to control the operation of the nuclear power plant's rod control system and boronizing system, causing the unit power to decrease towards 0, achieving a reduction in reactivity to below a set threshold (which can be 0.99) and an average reactor coolant temperature below a set temperature (which can be 260°C) within a seventh set time (which can be 6 hours). It should be noted that the power reduction technology of nuclear power plants through the nuclear power plant rod control system and boronizing system is a mature technology. The specific operation process can be referred to the existing technology, and will not be repeated here.

[0045] Step S503 includes: when the radiochemical data is in the third specific activity range, outputting a third operating command; after the third operating command is output, monitoring the changes in the radiochemical data, and when the radiochemical data cannot recover to a smaller specific activity range within a fifth set time, outputting a fifth operating command. The third operating command is used to achieve at least one of the following controls: controlling the main loop water to be discharged into the boron recovery system, controlling the scavenging gas from the volumetric control box in the chemical and volumetric control system to the waste gas treatment system, and controlling the desalination bed in the chemical and volumetric control system to maintain maximum purification flow. Understandably, under the action of the third operating command, the specific activity of iodine radioisotopes and inert gases can be effectively reduced, typically enabling the radiochemical data to recover from the third specific activity range to the second specific activity range within the fifth set time.

[0046] Step S504 includes: when the radiochemical data is in the fourth specific activity range, outputting a fourth operating command; after the fourth operating command is output, monitoring changes in the radiochemical data; when the radiochemical data cannot recover to a smaller specific activity range within an eighth set time, outputting a sixth operating command to further reduce unit power. The fourth operating command controls the unit to reduce power so that the radiochemical data returns to the third specific activity range within the eighth set time (which can be 6 hours). The fourth operating command can reduce power by controlling the operation of the nuclear power plant's rod control system and boronization system. The sixth operating command increases the power reduction based on the fourth operating command.

[0047] In some embodiments, the nuclear power plant fuel assembly irradiation management method may further include steps S601 to S604.

[0048] Step S601 includes: when the radiochemical data is within a first specific activity range, fitting a specific activity curve based on the acquired radiochemical data, and determining whether the specific activity of the specific activity curve shows an upward trend; when the specific activity of the specific activity curve shows an upward trend, determining whether the increase in the specific activity curve is greater than a first preset percentage; when the increase in the specific activity curve is greater than the first preset percentage, sampling radiochemical data N7 times per day. The specific activity curve includes an iodine radioisotope (specific activity) curve and an inert gas (specific activity) curve. When the increase in both the iodine radioisotope curve and the inert gas curve is greater than the first preset percentage, it is determined that the increase in the specific activity curve is greater than the first preset percentage; otherwise, it is determined that the increase in the specific activity curve is not greater than the first preset percentage. Furthermore, the increase is calculated as (maximum specific activity - minimum specific activity) / minimum specific activity.

[0049] In some embodiments, the first set percentage can be equal to 20%, and N7 can be equal to 1.

[0050] Step S602 includes: when the radiochemical data is in the second specific activity range, sampling the radiochemical data N8 times per day. Here, N8 can be equal to 1.

[0051] Step S603 includes: when the radiochemical data is in the third specific activity range, sampling the radiochemical data N9 times per day. Here, N9 can be equal to 3.

[0052] Step S604 includes: when the radiochemical data is in the second specific activity range or the third specific activity range, acquiring the unit's load change parameters; determining whether the load change amplitude is greater than a second set percentage based on the load change parameters; when the load change amplitude is greater than the second set percentage, determining whether the duration of the load change amplitude being greater than the second set percentage is greater than a sixth set time; when the duration is greater than the sixth set time, adding N to the radiochemical data within the time interval T1 to T2. 10 The sampling is performed once. The second set percentage can be equal to 15%, the sixth set time can be equal to 1 hour, T1 can be equal to 2, and T2 can be equal to 6.

[0053] In some embodiments, the nuclear power plant fuel assembly irradiation management method may further include steps S701 to S704.

[0054] Step S701 includes: acquiring images of preset checkpoints before the start of the overhaul, thus obtaining a first image. The preset checkpoints may include several checkpoints for the entry and exit of personnel, equipment, and materials during the overhaul.

[0055] Step S702 includes: during the overhaul, preventing foreign objects from entering the steam generator by setting up a foreign object barrier around the steam generator.

[0056] Step S703 includes: acquiring a second image of the preset gate after the overhaul is completed.

[0057] Step S704 includes: determining the presence of foreign objects based on the first and second captured images. Specifically, staff can use an image comparison algorithm to compare the first and second captured images with preset standard images (images already determined to be free of foreign objects, such as the first and second captured images taken during previous overhauls) to determine whether foreign objects exist at preset checkpoints. When a foreign object is found, an alert signal is output, prompting staff to remove it promptly. To improve accuracy, the first and second captured images are preferably taken from cameras installed at the same location and at the same angle. Essentially, one checkpoint can correspond to one camera, and at least one photo is taken at each checkpoint; that is, the first and second captured images each include a photo corresponding to each checkpoint. Alternatively, staff can manually observe and compare the first and second captured images. While this is more labor-intensive, it provides high accuracy in determining the presence of foreign objects.

[0058] It should be noted that foreign objects entering the steam generator or shut-off point may affect the reactor's reactivity due to foreign object intrusion, thereby affecting irradiation.

[0059] In some embodiments, the nuclear power plant fuel assembly irradiation management method may further include steps S801 and S802.

[0060] Step S801 includes: During the overhaul, acquiring the parameters to be detected for the fuel assemblies. These parameters may include information on surface foreign matter residue, weight change, and position offset. Surface foreign matter residue information can be obtained through existing detection equipment or manual inspection by personnel to determine the presence of foreign matter on the fuel assembly surface. Weight change information may include the weight difference of the fuel assembly before and after multiple refuelings; to simplify the operation, the weight difference before and after the third refueling of the fuel assembly can be specifically recorded. Position offset information may include the directional offset of the fuel assembly before and after multiple refuelings (i.e., the positional difference of the fuel assembly before removal and after installation); to simplify the operation, the directional offset of the fuel assembly before and after the third refueling of the fuel assembly can be specifically recorded.

[0061] Step S802 includes: determining the abnormality of the fuel assembly based on the parameters to be detected. Specifically, when it is determined that there is foreign matter on the surface of the fuel assembly based on the foreign matter residue information, a prohibition on fuel assembly entry warning signal is output to prompt the personnel to prohibit the fuel assembly from entering the fuel assembly. When it is determined that the weight difference of the fuel assembly before and after entering the fuel assembly is greater than a set weight threshold based on the weight change information, a weight abnormality warning signal is output to prompt the refueling operator to further check whether there is an abnormality in the fuel assembly. When it is determined that the component orientation offset of the fuel assembly is greater than a set offset (e.g., 1.5mm) based on the position offset information, a position adjustment warning signal is output to remind the personnel to calibrate the position of the fuel assembly.

[0062] Understandably, abnormalities in the fuel assembly can affect the unit's reactivity and thus irradiation. This embodiment ensures the integrity of the fuel assembly and the standardization of its operation, which helps to avoid abnormal specific activity in the primary loop.

[0063] This invention also provides a nuclear power plant fuel assembly irradiation management system, such as... Figure 2 As shown, the nuclear power plant fuel assembly irradiation management system may include an operation period determination unit 1, a strategy determination unit 2, a data acquisition unit 3, an interval determination unit 4, and an instruction generation unit 5.

[0064] The operating period determination unit 1 is used to determine the operating period of the unit.

[0065] Strategy determination unit 2 is used to determine the data sampling strategy based on the unit's current operating period. It should be noted that the specific process for determining the data sampling strategy can be found in the nuclear power plant fuel assembly irradiation management method described above, and will not be repeated here.

[0066] The data acquisition unit 3 is used to acquire radiometric data according to the data sampling strategy.

[0067] The interval determination unit 4 is used to determine the specific activity interval of the radiochemical data. It should be noted that the specific process for determining the specific activity interval of the radiochemical data can be referred to the nuclear power plant fuel assembly irradiation management method described above, and will not be repeated here.

[0068] Command generation unit 5 is used to output operating commands to avoid specific activity anomalies based on the specific activity range of the radiochemical data. It should be noted that the specific process of executing the commands can be found in the nuclear power plant fuel assembly irradiation management method described above, and will not be repeated here.

[0069] In some embodiments, such as Figure 2 As shown, the nuclear power plant's fuel assembly irradiation management system may also include a camera unit 6, an image analysis unit 7, a foreign object containment barrier 8, and a fuel assembly monitoring unit 9.

[0070] The shooting unit 6 is used to shoot preset gates before and after the overhaul to obtain the first and second shooting images.

[0071] Image analysis unit 7 is used to determine the extent of foreign object leakage based on the first and second captured images. It should be noted that the specific process for determining the extent of foreign object leakage based on the first and second captured images can be found in the nuclear power plant fuel assembly irradiation management method described above, and will not be repeated here.

[0072] Foreign object containment barrier 8 is used to surround the steam generator during major overhauls to prevent foreign objects from entering the steam generator during the overhaul.

[0073] The fuel assembly monitoring unit 9 is used to acquire the parameters to be detected of the fuel assembly during overhaul, determine the abnormal conditions of the fuel assembly based on the parameters to be detected, and output relevant prompt signals based on the abnormal conditions.

[0074] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0075] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0076] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0077] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for managing the irradiation of fuel assemblies in a nuclear power plant, characterized in that, include: Determine the operating period of the unit; wherein, the unit status includes the normal operation period, the pre-overhaul monitoring period, the post-overhaul monitoring period, and the abnormal period; The data sampling strategy is determined based on the operating period of the unit. Acquire radiometric data according to the data sampling strategy described above; Determine the specific activity range of the radiochemical data; Based on the specific activity range of the radiochemical data, an operating instruction is output to avoid abnormal specific activity.

2. The nuclear power plant fuel assembly irradiation management method according to claim 1, characterized in that, The normal operation period includes the period during which the unit operates at normal power and during normal power increases and decreases. The post-overhaul monitoring period is from the start-up of the unit after the overhaul to the first set time after the first full power. The pre-overhaul monitoring period is from the second set time before the overhaul to the start time of the overhaul. The abnormal period is from the time when the unit abnormality is discovered to the time when the unit abnormality is eliminated. The step of determining the data sampling strategy based on the unit status includes: When the unit is in the normal operation period, the data sampling strategy is set to the first data sampling strategy; the first data sampling strategy includes: sampling radiochemical data N1 times a day after entering the normal operation period each time until the unit power is stable and continues for a third set time, and sampling radiochemical data N2 times a week after the unit power is stable and continues for the third set time. When the unit is in the pre-overhaul monitoring period, the data sampling strategy is set to the second data sampling strategy; the second data sampling strategy includes: sampling radiochemical data N3 times a day, and continuously sampling radiochemical data N4 times at a set frequency after the unit is shut down. When the unit is in the post-overhaul monitoring period, the data sampling strategy is set to the third data sampling strategy; the third data sampling strategy includes: sampling radiochemical data N5 times per day; When the unit is in the abnormal period, the data sampling strategy is set to the fourth data sampling strategy; the fourth data sampling strategy includes: when the unit abnormality will cause abnormal changes in the unit power, the number of sampling times of radiochemical data is increased by N6 times within a fourth set time after the abnormal change in the unit power.

3. The nuclear power plant fuel assembly irradiation management method according to claim 2, characterized in that, The first set time is 1 month, the third set time is 7 days, and the fourth set time is 24 hours; And / or, N1= N3= N5= N6 =1, N2=2, N4=6, the set frequency is once per hour.

4. The nuclear power plant fuel assembly irradiation management method according to claim 3, characterized in that, The radiochemical data includes the specific activity of iodine radioisotopes and inert gases; Determining the specific activity range of the radiochemical data includes: When the specific activity of the iodine radioisotope in the radiochemical data is less than A1 and the specific activity of the inert gas is less than A2, the radiochemical data is determined to be in the first specific activity range. When the specific activity of the iodine radioisotope in the radiochemical data is less than A3 and greater than or equal to A1, and the specific activity of the inert gas is less than A4 and greater than or equal to A2, the radiochemical data is determined to be in the second specific activity range. When the specific activity of the iodine radioisotope in the radiochemical data is less than A5 and greater than or equal to A3, and the specific activity of the inert gas is less than A6 and greater than or equal to A4, the radiochemical data is determined to be in the third specific activity range. When the specific activity of the iodine radioisotope in the radiochemical data is greater than or equal to A5, and the specific activity of the inert gas is greater than or equal to A6, the radiochemical data is determined to be in the fourth specific activity range.

5. The nuclear power plant fuel assembly irradiation management method according to claim 4, characterized in that, The operation instructions output based on the specific activity range of the radiochemical data to avoid specific activity anomalies include: When the radiochemical data is within the first specific activity range, a first operating instruction is output; wherein, the first operating instruction is used to control the unit to increase or decrease power through a dilution boronization strategy, and to limit the rate of increase or decrease of power within a set rate; When the radiochemical data is within the second specific activity range, a second operating instruction is output. After the second operating instruction is output, the changes in the radiochemical data are monitored. When the radiochemical data cannot recover to a smaller specific activity range within a fifth set time, a fifth operating instruction is output. The second operating instruction is used to prohibit the unit from performing load tracking and power increase / decrease. The fifth operating instruction is used to control the operation of the nuclear power plant's rod control system and boronizing system, so that the unit's reactivity drops below a set threshold and the reactor coolant average temperature drops below a set temperature within a seventh set time. When the radiochemical data is within the third specific activity range, a third operating instruction is output; after the third operating instruction is output, the change of the radiochemical data is monitored, and when the radiochemical data cannot recover to a smaller specific activity range within the fifth set time, the fifth operating instruction is output; wherein, the third operating instruction is used to achieve at least one of the following controls: controlling the main loop water to be discharged into the boron recovery system, controlling the volumetric control box in the chemical and volumetric control system to scaveng the exhaust gas treatment system, and controlling the desalination bed in the chemical and volumetric control system to maintain the maximum purification flow rate; When the radiochemical data is within the fourth specific activity range, a fourth operating instruction is output; after the fourth operating instruction is output, the changes in the radiochemical data are monitored, and when the radiochemical data cannot recover to a smaller specific activity range within an eighth set time, a sixth operating instruction is output to further reduce the unit power; wherein, the fourth operating instruction is used to control the unit to reduce power.

6. The nuclear power plant fuel assembly irradiation management method according to claim 5, characterized in that, The nuclear power plant fuel assembly irradiation management method also includes: Adjusting the data sampling strategy based on the specific activity range of the radiochemical data includes: When the radiochemical data is within the first specific activity range, a specific activity curve is fitted based on the radiochemical data acquired during the period, and it is determined whether the specific activity is trending upward based on the specific activity curve; when the specific activity is trending upward, it is determined whether the increase in the specific activity curve is greater than a first set percentage; when the increase in the specific activity curve is greater than the first set percentage, radiochemical data is sampled N7 times per day. When the radiochemical data is within the second specific activity range, N8 radiochemical data samples are taken daily. When the radiochemical data is within the third specific activity range, N9 radiochemical data samples are taken daily. When the radiochemical data is within the second specific activity range or the third specific activity range, the unit's load change parameters are also acquired; based on the load change parameters, it is determined whether the load change amplitude is greater than a second set percentage; when the load change amplitude is greater than the second set percentage, it is determined whether the duration of the load change amplitude being greater than the second set percentage is greater than a sixth set time; when the duration is greater than the sixth set time, N is added to the radiochemical data within the time interval T1 to T2. 10 Second sampling.

7. The nuclear power plant fuel assembly irradiation management method according to claim 6, characterized in that, The first set percentage is 20%, and the second set percentage is 15%. And / or, N7 = N8 = N 10 =1, N9=3, T1=2, T2=6.

8. The nuclear power plant fuel assembly irradiation management method according to any one of claims 1 to 7, characterized in that, The nuclear power plant fuel assembly irradiation management method also includes: The first image is obtained by capturing images of the preset checkpoint before the start of the overhaul. During the overhaul, a foreign object barrier is installed around the steam generator to prevent foreign objects from entering the steam generator. The second image is obtained by capturing images of the preset checkpoint after the overhaul is completed. The extent of foreign object loss is determined based on the first and second captured images.

9. The nuclear power plant fuel assembly irradiation management method according to claim 8, characterized in that, The nuclear power plant fuel assembly irradiation management method also includes: During the overhaul, parameters to be tested for the fuel assembly are acquired; these parameters include information on residual foreign matter on the surface, weight changes, and positional offsets. The abnormal condition of the fuel assembly is determined based on the parameters to be detected.

10. A nuclear power plant fuel assembly irradiation management system, characterized in that, include: The operation period determination unit is used to determine the operation period of the unit; wherein, the unit status includes normal operation period, pre-overhaul monitoring period, post-overhaul monitoring period, and abnormal period; The strategy determination unit is used to determine the data sampling strategy based on the operating period of the unit; The data acquisition unit is used to acquire radiometric data according to the data sampling strategy; An interval determination unit is used to determine the specific activity interval in which the radiochemical data is located; The instruction generation unit is used to output an operation instruction to avoid specific activity abnormalities based on the specific activity range of the radiochemical data.

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