Method and device for deciding autonomous operation of nuclear power unit

Abstract

The invention discloses a nuclear power unit autonomous operation decision method and device, and the method comprises the steps: collecting the equipment state information and equipment performance information of a nuclear power unit in real time through a PHM tool in the operation process of the unit, and if the equipment state is changed or the equipment performance is reduced, determining that the nuclear power unit is an autonomous operation decision; if so, analyzing a related accident sequence of the equipment by using a simulation technology to determine a sequence result; according to the sequence consequence obtained by simulation analysis, updating a PSA model of the nuclear power unit to carry out risk assessment, obtaining a risk value, and judging whether the risk value is in a risk yellow area; if so, establishing an alternative scheme set; analyzing the alternative scheme set by using a deterministic theory analysis method to determine a first scheme set; according to the first scheme set, a probability theory analysis method is used for analysis, and a second scheme set is formed; and for the second scheme set, based on the deterministic theory safety index, the probability theory safety index, the economic index and weighting, comprehensive decision making is carried out, and an optimal scheme is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plant safety and operation, and in particular to a method and device for autonomous operation decision-making of a nuclear power unit. Background Art

[0002] During the operation of nuclear power units, it is inevitable that equipment performance will degrade. At this time, it may be necessary to adjust the unit's operating strategy to ensure nuclear safety. Currently, the operation and control of nuclear power units are mainly based on the pre-compiled "Operation Technical Specifications" and related procedural documents, and there are the following problems:

[0003] (1) The formulation of the Operation Technical Specifications is aimed at ensuring nuclear safety and adopts conservative decisions. When an abnormality occurs in a unit, it is often required to be restored to normal within a limited time. Otherwise, the unit needs to be withdrawn to a specified state (usually a cold shutdown or hot shutdown state), which has a certain impact on the economic efficiency of the nuclear power unit;

[0004] (2) The above-mentioned "Operation Technical Specifications" and regulations can only put forward fixed operating requirements for limited abnormal conditions, and it is difficult to fully cover the various complex situations that may be encountered in the actual operation of nuclear power units;

[0005] (3) The above-mentioned "Operational Technical Specifications" and regulations are mainly formulated based on relevant analysis results under the design basis conditions. They do not take into account the situation that as the nuclear power unit continues to operate, some equipment is in a non-design basis state due to performance degradation. It is difficult to completely avoid unconservative decisions (especially in the middle and late stages of the unit's life), which may have an adverse impact on nuclear safety.

[0006] The existing patent CN108416526B discloses an online time-related risk monitoring system and method for nuclear power plant production plan, which includes an online reliability database module for online acquisition of real-time configuration information of nuclear power plants, automatic update of equipment reliability data, a planned configuration management module for managing the planned initial configuration of each device, and the planned configuration composed of each planned event; an online risk monitoring model update module for acquiring real-time reliability data of equipment from the online reliability database module, and respectively acquiring the planned initial configuration and planned configuration from the planned configuration management module, and updating according to the preset update rules of the Living-PSA model; and a risk calculation module for acquiring the updated Living-PSA model and realizing the calculation of quantitative and qualitative risk indicators. This method focuses on the risk detection of nuclear power units, and does not solve the problem of equipment performance degradation in the operation state of nuclear power units in the prior art, adjusting the plan under the condition of meeting safety requirements, and avoiding unplanned shutdowns.

[0007] The existing patent CN 110009228B discloses a design method for a nuclear power plant diversity protection system that combines probability theory with determinism. The importance of systems and functions is identified through probability theory, and the safety functions and systems that must be considered by the diversity protection system are determined; the minimum cut set of the safety system function is determined through determinism, and the functional requirements of the diversity protection system are determined. The functional requirements of the diversity protection system are preliminarily determined by combining the analysis results of probability theory and determinism, and the corresponding protection signal settings are considered. Finally, the optimal diversity protection system settings are determined through quantitative calculations of probability theory and determinism. This method focuses on the construction of nuclear power safety systems, and does not solve the problem of reduced equipment performance under the operating state of nuclear power units in the prior art, adjusting the plan under safety conditions, and avoiding unplanned shutdowns.

[0008] In summary, the above two existing patents do not solve the problem in the prior art that the performance of the equipment is reduced when the nuclear power unit is in operation, and the adjustment plan is not performed under the condition of safety to avoid unplanned shutdown. Summary of the invention

[0009] Based on the above technical problems, the present invention proposes a method and device for autonomous operation decision-making of nuclear power units, which solves the problem of flexible adjustment of plans and avoidance of unplanned shutdowns during operation of nuclear power units in the prior art.

[0010] To achieve the above object, the present invention proposes a method for autonomous operation decision-making of a nuclear power unit.

[0011] A method for autonomous operation decision-making of a nuclear power unit, comprising:

[0012] The equipment status information and equipment performance information of the nuclear power unit are collected by the PHM tool, wherein the equipment status information includes the equipment operation status and the equipment failure status, and the equipment performance information includes the capacity parameter. If the collected equipment status information is the equipment failure status, the initial PSA model is updated by the probability theory method to obtain the first PSA model. If the capacity parameter in the collected equipment performance information decreases, the deterministic method is used to perform simulation analysis first, and then the initial PSA model is updated by the probability theory method to obtain the first PSA model;

[0013] Perform risk assessment according to the first PSA model to obtain a risk value, and determine whether the risk value is in the risk yellow zone;

[0014] If you are in the yellow risk zone, then:

[0015] Establishing a set of alternative solutions, analyzing the set of alternative solutions using a deterministic analysis method, and determining a set of solutions;

[0016] According to the solution set 1, a probability analysis method is used to analyze to form a solution set 2;

[0017] According to the second solution set, the optimal solution is obtained.

[0018] Furthermore, if the collected device status information is a device failure status, the initial PSA model is updated by a probability theory method to obtain a first PSA model, including:

[0019] The initial PSA model includes an event tree model and / or a fault tree model.

[0020] Further, if the capability parameter in the collected device performance information decreases, a deterministic analysis method is first used for simulation, and then the initial PSA model is updated by a probabilistic method to obtain the first PSA model, including:

[0021] The capability parameters and reliability parameters are input into simulation software to obtain analysis results, and the initial PSA model is updated according to the analysis results in combination with a probability theory method to obtain the first PSA model.

[0022] Further, performing risk assessment according to the first PSA model to obtain a risk value, and determining whether the risk value is in a risk yellow zone, includes:

[0023] The risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value;

[0024] The first PSA model is input into the analysis software to obtain the risk value, and it is determined whether the risk value is in the risk yellow zone.

[0025] Furthermore, the risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value, and further comprising:

[0026] The risk threshold is twice the baseline risk, and the risk danger value is an empirically preset value.

[0027] Furthermore, it also includes:

[0028] If it is not in the risk yellow zone, determine whether the risk value is in the risk red zone. The risk red zone is when the risk value is greater than or equal to the risk danger value. If the risk value is in the risk red zone, shut down the reactor immediately.

[0029] Furthermore, a set of alternative solutions is established, and the set of alternative solutions is analyzed using a deterministic analysis method to determine a set of solutions, including:

[0030] The set of alternative solutions includes fixed operation of nuclear power units, switching to other equipment or systems with the same or similar functions, and measures to reduce load;

[0031] According to the alternative solution set, the PSA model of the nuclear power unit is simulated to obtain a risk indicator set, and the solutions corresponding to the risk indicators in the alternative solution set that are lower than the preset indicators are selected from the risk indicator set to determine solution set one.

[0032] Furthermore, the corresponding solutions in the set of alternative solutions for risk indicators lower than the preset indicators include:

[0033] The risk indicator and the preset indicator are both the peak temperature of the reactor core inner cladding.

[0034] Furthermore, according to the solution set 1, a probability analysis method is used to analyze to form a solution set 2, including:

[0035] According to the scheme set one, the PSA model of the nuclear power unit is updated, and the updated PSA model of the nuclear power unit is input into the analysis software for risk assessment to obtain a risk value set, and the scheme corresponding to the risk value in the scheme set one that is lower than the risk threshold in the risk value set is selected to determine the scheme set two.

[0036] Furthermore, according to the second solution set, the optimal solution is obtained, including:

[0037] A weight of one is set for the risk indicator, and a weight of two is set for the risk value of the solution. The risk indicator and the risk value of the solution corresponding to the solution in solution set two are calculated according to the weight of one and the weight of two to obtain a solution score. The best solution is determined according to the solution score and the power in solution set two.

[0038] To achieve the above-mentioned purpose, the present invention proposes a nuclear power unit autonomous operation decision-making device.

[0039] A nuclear power unit autonomous operation decision-making device, comprising:

[0040] A collection and establishment module, used to collect the equipment status information and equipment performance information of the nuclear power unit through the PHM tool, the equipment status information includes the equipment operation status and the equipment failure status, the equipment performance information includes the capacity parameter, if the collected equipment status information is the equipment failure status, the initial PSA model is updated by the probability theory method to obtain the first PSA model, if the capacity parameter in the collected equipment performance information decreases, the deterministic method is used to perform simulation analysis, and then the initial PSA model is updated by the probability theory method to obtain the first PSA model;

[0041] A risk assessment module, configured to perform risk assessment according to the first PSA model to obtain a risk value, and determine whether the risk value is in a risk yellow zone;

[0042] A first determination module is used to establish a set of alternative solutions, analyze the set of alternative solutions using a deterministic analysis method, and determine a set of solutions.

[0043] The second determination module is used to analyze the solution set 1 using a probability analysis method to form a solution set 2;

[0044] The decision module is used to obtain the optimal solution according to the second solution set.

[0045] Furthermore, in the acquisition establishment module:

[0046] The initial PSA model includes an event tree model and / or a fault tree model.

[0047] Furthermore, in the acquisition establishment module:

[0048] The capability parameters and reliability parameters are input into simulation software to obtain analysis results, and the initial PSA model is updated according to the analysis results in combination with a probability theory method to obtain the first PSA model.

[0049] Furthermore, in the risk assessment module:

[0050] The risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value;

[0051] The first PSA model is input into the analysis software to obtain the risk value, and it is determined whether the risk value is in the risk yellow zone.

[0052] Furthermore, in the risk assessment module:

[0053] The risk threshold is twice the baseline risk, and the risk danger value is an empirically preset value.

[0054] Furthermore, in the risk assessment module:

[0055] If it is not in the risk yellow zone, determine whether the risk value is in the risk red zone. The risk red zone is when the risk value is greater than or equal to the risk danger value. If the risk value is in the risk red zone, shut down the reactor immediately.

[0056] Further, in the first determining module:

[0057] The set of alternative solutions includes fixed operation of nuclear power units, switching to other equipment or systems with the same or similar functions, and measures to reduce load;

[0058] According to the alternative solution set, the PSA model of the nuclear power unit is simulated to obtain a risk indicator set, and the solutions corresponding to the risk indicators in the alternative solution set that are lower than the preset indicators are selected from the risk indicator set to determine solution set one.

[0059] Further, in the first determining module:

[0060] The risk indicator and the preset indicator are both the peak temperature of the reactor core inner cladding.

[0061] Further, in the second determining module:

[0062] According to the scheme set one, the PSA model of the nuclear power unit is updated, and the updated PSA model of the nuclear power unit is input into the analysis software for risk assessment to obtain a risk value set, and the scheme corresponding to the risk value in the scheme set one that is lower than the risk threshold in the risk value set is selected to determine the scheme set two.

[0063] Furthermore, in the decision module:

[0064] A weight of one is set for the risk indicator, and a weight of two is set for the risk value of the solution. The risk indicator and the risk value of the solution corresponding to the solution in solution set two are calculated according to the weight of one and the weight of two to obtain a solution score. The best solution is determined according to the solution score and the power in solution set two.

[0065] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0066] 1. The present invention determines that the performance of nuclear power unit equipment has declined, simulates according to the event tree model in the PSA model, simulates different event situations when the equipment performance has declined, updates the PSA model, and then screens the scheme through deterministic safety analysis, probabilistic safety analysis and economic analysis. Finally, the unplanned shutdown events are reduced by flexibly adjusting the operation scheme, thereby improving the economic efficiency of the nuclear power unit.

[0067] 2. The present invention simulates the event tree model in the PSA model and simulates different event situations when the equipment performance decreases. This solution solves the problem that the previous nuclear power unit operation plan cannot adapt to the various complex situations encountered in the operation of nuclear power units. The new technology can handle more types of abnormal situations through machine decision-making, making operation control more accurate and effective.

[0068] 3. The present invention makes decisions through deterministic and probabilistic analysis methods in the operation of nuclear power unit equipment, so that comprehensive judgments can be made in real time when equipment performance changes. This method not only ensures the safety of nuclear power plants, but also provides more flexible response strategies when faced with emergencies such as equipment failure or performance degradation, helping to avoid excessive restrictions that may be caused by simply taking conservative measures in the past.

[0069] 4. This method realizes autonomous decision-making by machines based on scientific analysis. Machines assist human decision-making, which is more scientific and objective and can avoid the influence of human errors. The operator only needs to review the risk information and suggested solutions provided by the machine before making the final decision. Compared with the current method in which operators review a large number of documents and make decisions, this method can greatly reduce their decision-making pressure, especially in complex situations where the regulations do not directly stipulate the response measures, reduce the subjectivity of the decision-making process, and avoid human errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0071] Figure 1 A flow chart of a method for autonomous operation decision-making of a nuclear power unit according to an embodiment of the present invention;

[0072] Figure 2 A schematic diagram of a PSA model event tree model according to an embodiment of the present invention;

[0073] Figure 3 A schematic diagram of a PSA model fault tree model according to an embodiment of the present invention;

[0074] Figure 4 A schematic diagram of a PSA model fault tree model according to an embodiment of the present invention;

[0075] Figure 5 A schematic diagram of a PSA model event tree model according to an embodiment of the present invention;

[0076] Figure 6 A schematic diagram of a PSA model simulation output result according to an embodiment of the present invention;

[0077] Figure 7 The present invention is a schematic diagram of a nuclear power unit autonomous operation decision-making device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0078] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0079] The present invention is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention.

[0080] Example

[0081] In order to solve the problem in the prior art that nuclear power units cannot flexibly adjust their operation strategies when facing equipment performance degradation, the present invention proposes a method and device for autonomous operation decision-making of nuclear power units.

[0082] To achieve the above object, the present invention proposes a method for autonomous operation decision-making of a nuclear power unit.

[0083] like Figure 1 A flow chart of a method for autonomous operation decision-making of a nuclear power unit according to an embodiment of the present invention is shown in FIG. Figure 1 As mentioned above, the process mainly includes the following steps:

[0084] S1. The equipment status information and equipment performance information of the nuclear power unit are collected through the PHM tool. The equipment status information includes the equipment operation status and the equipment failure status. The equipment performance information includes the capacity parameters. If the collected equipment status information is the equipment failure status, the initial PSA model is updated through the probability theory method to obtain the first PSA model. If the capacity parameters in the collected equipment performance information decrease, a simulation analysis is first performed through the deterministic method, and then the initial PSA model is updated through the probability theory method to obtain the first PSA model.

[0085] PHM (Prognostics and Health Management) tools are used to monitor and predict equipment status information and equipment performance information. The results of monitoring and prediction can be equipment failure, capacity parameters and reliability parameters.

[0086] According to the initiating event, the whole site is out of power, and the initial PSA model of the nuclear power unit is established. The initial PSA model includes event tree and fault tree. Combined with the CDF of different events, the event tree of the nuclear power unit is established as follows: Figure 2 An exemplary portion of is shown. Figure 2 The initiating events shown in the figure are power operation conditions with loss of external power supply A07, D01, D02, S02, D03, G04, D05, TSAHE1, J02, J04, D05, TSAHE2, H08, S01, H09, E04, C02, a total of 25 event sequences, where Freq is the accident frequency and Conseq is the consequence. The fault tree is as follows Figure 3 As shown, the pump body failure event @ASGA1311-1 consists of a pneumatic pump demand failure ASG003POP_FD or a pneumatic operation failure ASG003POP_FW.

[0087] Based on the monitoring and prediction results, such as Figure 3 If the device status shown changes to failure, the fault tree model is updated to obtain the first PSA model; Figure 4 If the capability parameter among the collected equipment performance parameters is lower than 100% or the reliability parameter is lower than the initial value, it is judged that the performance is degraded, and the obtained capability parameter and reliability parameter are transferred to the simulation software, and the initial PSA model is updated to obtain the first PSA model.

[0088] In this implementation, PHM obtains initial inputs related to equipment performance degradation through monitoring and prediction, which may include performance parameters and reliability parameters. The performance parameters are the performance degradation of two auxiliary water supply pneumatic pumps, the capacity parameter maximum flow rate is reduced to 75% of the rated flow rate (less than 100%), the reliability parameter pump body operation failure rate changes from 1.3E-04 / h to 1.3E-03 / h, and the demand failure probability of the pump body changes from 4.2E-05 to 4.2E-04 (reduced reliability), so it is determined that the equipment performance has deteriorated.

[0089] Further, according to the equipment information of the nuclear power unit, if the capability parameter in the collected equipment performance information decreases, a deterministic analysis method is first used for simulation, and then the initial PSA model is updated by a probabilistic method to obtain the first PSA model, including:

[0090] PHM obtains 75% of the capability parameters, and the event tree sequence related to the device in the PSA model ( Figure 2 The simulation analysis is performed on the sequence 4-sequence 23 in the example. The analysis results are as follows: Figure 4 As shown, the Conseq of sequence 5, sequence 6 and sequence 17 are changed from OK to CD, and the update is as follows Figure 5 The first PSA model is shown.

[0091] The equipment reliability parameters obtained by PHM are input into the initial PSA model to update the parameters of the fault tree.

[0092] S2, performing risk assessment according to the first PSA model to obtain a risk value, and determining whether the risk value is in the risk yellow zone, and if so, proceeding to the next step.

[0093] Furthermore, the risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value, and further comprising:

[0094] The CDF of the initial PSA model of the nuclear power unit equipment is set as the benchmark risk, twice the benchmark risk is set as the risk threshold, the risk danger value is set according to the experience value, and the range interval is set for the risk value obtained by prediction during the operation of the nuclear power unit. The range in which the risk value is greater than or equal to the risk threshold and less than the risk danger value is set as the risk yellow zone, and the range in which the risk value is greater than or equal to the risk danger value is set as the risk red zone, and it is judged whether the risk value is between the risk yellow zones.

[0095] In the specific implementation, the PSA analysis software is used to analyze and calculate the initial PSA model and the first PSA model, and the risk value CDF of the initial PSA model and the first PSA model are obtained, which are 1.26E-07 / reactor-year and 1.32E-6 / reactor-year respectively. The risk red zone is set as the risk value greater than or equal to 1.32E-5 / reactor-year. Since the risk value CDF of the first PSA model 1.32E-6 / reactor-year is greater than 2 times the risk value CDF of the initial PSA model 1.26E-07 / reactor-year, that is, the risk threshold, and is less than the risk danger value, it is determined that the risk value is in the risk yellow zone, and the next step is to establish a set of alternative solutions.

[0096] In another embodiment, the initial PSA model and the first PSA model are analyzed and calculated using PSA analysis software to obtain the risk value CDFs of the initial PSA model and the first PSA model, which are 1.26E-07 / reactor-year and 1.32E-4 / reactor-year, respectively. The risk red zone is set to a risk value greater than or equal to 1.32E-5 / reactor-year. The obtained risk value of 1.32E-4 / reactor-year is greater than 1.32E-5 / reactor-year. Therefore, it is determined that the risk value is within the risk red zone, and the nuclear power plant is shut down immediately.

[0097] S3, establishing a set of alternative solutions, analyzing the set of alternative solutions using a deterministic analysis method, and determining a set of solutions.

[0098] Generally speaking, the establishment of a set of alternative options can be composed of three aspects: fixed operation of nuclear power units, switching to other equipment or systems with the same or similar functions, and measures to reduce load.

[0099] The first aspect is based on the fixed operation of nuclear power units required by existing power plant management documents. The "Operation Technical Specifications" require that "if two steam-driven feedwater pumps are unavailable, the unit will retreat to the NS / SG mode with RRA access within 24 hours."

[0100] Secondly, according to the system design, switching to other equipment or systems with the same or similar functions (such as switching to the standby column) is the principle applicable to the operating equipment. In this example, the auxiliary water supply pump is a long-term standby equipment and does not need to be considered for switching, so no corresponding plan is generated.

[0101] The other new solutions specifically considered in the third aspect are based on the consideration of matching capacity with load. Corresponding measures to reduce the "load" can be taken, that is, "de-powering" the reactor, operating to reduce the unit's potential demand for the auxiliary feedwater pump's water supply capacity to match its capacity.

[0102] In the specific implementation, according to the Operation Technical Specification, the solution X1 = "the unit retreats to the NS / SG mode of RRA access". In the other new solutions considered in a targeted manner, based on the consideration of capacity and load matching, multiple power reduction solutions are generated with a "5%" gradient, including: X2 = "reducing power to 95%", X3 = "reducing power to 90%", X4 = "reducing power to 85%", and X5 = "reducing power to 80%", so the alternative solution set X = {X1, X2, X3, X4, X5} is obtained.

[0103] Based on each of the alternative solutions obtained, determinism is used to perform simulation analysis, the PSA model is updated, and the risk index of the operation of the nuclear power unit is calculated. In this embodiment, Figure 6 As shown, the risk index can be the peak temperature of the reactor core cladding. The reactor core temperature of each solution in the alternative solution set X is calculated by simulation software, that is, the risk index, and the corresponding risk index set M = {563.11K, 1238.4K, 768.22K, 609.87K} is obtained, as shown in Figure 6 As shown, the preset index, i.e., the temperature limit, is 1477K, and the scheme corresponding to the risk index set M that is lower than the preset index is selected to form a screened scheme set X1 = {X1, X3, X4, X5}.

[0104] S4, analyzing the solution set 1 using a probability analysis method to form a solution set 2.

[0105] For the solutions in solution set 1 X1, according to the simulation results, the PSA model is risk analyzed respectively, and the risk index in solution set 1 is obtained as CDF. The solutions with risk index less than the benchmark risk are grouped into solution set 2.

[0106] In this embodiment, the PSA model is updated with the four schemes corresponding to the scheme set X1, and the updated PSA model is input into the PSA software for calculation, and the risk value set obtained is R = {7.78E-09 / reactor-year, 2.05E-07 / reactor-year, 2.05E-07 / reactor-year, 2.05E-07 / reactor-year}, where the risk levels are all less than twice the benchmark risk, and thus the scheme set two X2 = {X1, X3, X4, X5} is obtained.

[0107] S5, obtaining the optimal solution according to the second solution set.

[0108] A weight of one is set for the risk indicator, and a weight of two is set for the risk value of the solution. The risk indicator and the risk value of the solution corresponding to the solution in solution set two are calculated according to the weight of one and the weight of two to obtain the solution score. The best solution is determined according to the solution score and the power in solution set two.

[0109] In the specific implementation, the solution set 2X 2 ={X1, X3, X4, X5} corresponds to the unit power of 0, 90% Ph, 85% Ph, 80% Ph. 2 The risk index and risk value corresponding to each scheme in the solution set are multiplied and added with weight 1 and weight 2 respectively to calculate the scheme score. Finally, the economic performance is judged according to the power generation to achieve the best scheme decision of solution set 2. 2 All the solutions meet the requirements for safe operation of nuclear power plants. Among them, solution X3 has the highest score and the best economic power generation. Therefore, X3 "reducing the unit power to 90% of the rated power" is selected as the optimal solution and pushed to the operator.

[0110] To achieve the above-mentioned object, the present invention proposes a decision-making device for autonomous operation of a nuclear power unit.

[0111] like Figure 7 FIG. 1 is a schematic diagram of a device for autonomous operation decision-making of a nuclear power unit according to an embodiment of the present invention. Figure 7 As shown, the device includes: a collection establishment module, a risk assessment module, a first determination module, a second determination module and a decision module. The functions of each module will be described in detail below.

[0112] The acquisition and establishment module is used to collect the equipment status information and equipment performance information of the nuclear power unit through the PHM tool. The equipment status information includes the equipment operation status and the equipment failure status. The equipment performance information includes the capacity parameters. If the collected equipment status information is the equipment failure status, the initial PSA model is updated by the probability theory method to obtain the first PSA model. If the capacity parameters in the collected equipment performance information decrease, the deterministic method is used to perform simulation analysis first, and then the initial PSA model is updated by the probability theory method to obtain the first PSA model.

[0113] Furthermore, in the acquisition establishment module:

[0114] The initial PSA model includes an event tree model and / or a fault tree model.

[0115] Furthermore, in the acquisition establishment module:

[0116] The capability parameters and the reliability parameters are input into simulation software to obtain analysis results, and the initial PSA model is updated according to the analysis results in combination with a probability theory method to obtain the first PSA model.

[0117] The risk assessment module is used to perform risk assessment according to the first PSA model to obtain a risk value, and determine whether the risk value is in a risk yellow zone.

[0118] Furthermore, in the risk assessment module:

[0119] The risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value;

[0120] The first PSA model is input into the analysis software to obtain the risk value, and it is determined whether the risk value is in the risk yellow zone.

[0121] Furthermore, in the risk assessment module:

[0122] The risk threshold is twice the baseline risk, and the risk danger value is an empirically preset value.

[0123] Furthermore, in the risk assessment module:

[0124] If it is not in the risk yellow zone, determine whether the risk value is in the risk red zone. The risk red zone is when the risk value is greater than or equal to the risk danger value. If the risk value is in the risk red zone, shut down the reactor immediately.

[0125] The first determination module is used to establish a set of alternative solutions, analyze the set of alternative solutions using a deterministic analysis method, and determine a set of solutions.

[0126] Further, in the first determining module:

[0127] The set of alternative solutions includes fixed operation of nuclear power units, switching to other equipment or systems with the same or similar functions, and measures to reduce load;

[0128] According to the alternative solution set, the PSA model of the nuclear power unit is simulated to obtain a risk indicator set, and the solutions corresponding to the risk indicators in the alternative solution set that are lower than the preset indicators are selected from the risk indicator set to determine solution set one.

[0129] Further, in the first determining module:

[0130] The risk indicator and the preset indicator are both the peak temperature of the reactor core inner cladding.

[0131] The second determination module is used to analyze the solution set 1 using a probability analysis method to form a solution set 2.

[0132] Further, in the second determining module:

[0133] According to the scheme set one, the PSA model of the nuclear power unit is updated, and the updated PSA model of the nuclear power unit is input into the analysis software for risk assessment to obtain a risk value set, and the scheme corresponding to the risk value in the scheme set one that is lower than the risk threshold in the risk value set is selected to determine the scheme set two.

[0134] The decision module is used to obtain the optimal solution according to the second solution set.

[0135] Furthermore, in the decision module:

[0136] A weight of one is set for the risk indicator, and a weight of two is set for the risk value of the solution. The risk indicator and the risk value of the solution corresponding to the solution in solution set two are calculated according to the weight of one and the weight of two to obtain a solution score. The best solution is determined according to the solution score and the power in solution set two.

[0137] It should be understood that a nuclear power unit autonomous operation decision-making device and a corresponding nuclear power unit autonomous operation decision-making method embodiment are consistent in description, so this embodiment will not be repeated.

[0138] In summary, it can be seen from the above description that the above embodiments of the present invention achieve the following technical effects:

[0139] 1. The present invention determines that the performance of nuclear power unit equipment has declined, simulates according to the event tree model in the PSA model, simulates different event situations when the equipment performance has declined, updates the PSA model, and then screens the scheme through deterministic safety analysis, probabilistic safety analysis and economic analysis. Finally, the unplanned shutdown events are reduced by flexibly adjusting the operation scheme, thereby improving the economic efficiency of the nuclear power unit.

[0140] 2. The present invention simulates the event tree model in the PSA model and simulates different event situations when the equipment performance decreases. This solution solves the problem that the previous nuclear power unit operation scheme cannot adapt to the various complex situations encountered in the operation of nuclear power units. The new technology can handle more types of abnormal situations through machine autonomous decision-making, making operation control more accurate and effective.

[0141] 3. The present invention makes autonomous decisions through deterministic and probabilistic analysis methods in the operation of nuclear power unit equipment, so that comprehensive judgments can be made in real time when equipment performance changes. This method not only ensures the safety of nuclear power plants, but also provides more flexible response strategies when faced with emergencies such as equipment failure or performance degradation, helping to avoid excessive restrictions that may be caused by simply taking conservative measures in the past.

[0142] 4. This method realizes autonomous decision-making by machines based on scientific analysis. Machines assist human decision-making, which is more scientific and objective and can avoid the influence of human errors. The operator only needs to review the risk information and suggested solutions provided by the machine before making the final decision. Compared with the current method in which operators review a large number of documents and make decisions, this method can greatly reduce their decision-making pressure, especially in complex situations where the regulations do not directly stipulate the response measures, reduce the subjectivity of the decision-making process, and avoid human errors.

[0143] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0144] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0145] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, which can be embodied in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a system including a processor or other system that can fetch instructions from an instruction execution system, apparatus or device and execute instructions), or used in combination with these instruction execution systems, apparatuses or devices.

[0146] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0147] It should be noted that, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. A method for autonomous operation decision-making of a nuclear power unit, characterized in that: include: The equipment status information and equipment performance information of the nuclear power unit are collected by the PHM tool, wherein the equipment status information includes the equipment operation status and the equipment failure status, and the equipment performance information includes the capacity parameter. If the collected equipment status information is the equipment failure status, the initial PSA model is updated by the probability theory method to obtain the first PSA model. If the capacity parameter in the collected equipment performance information decreases, the deterministic method is used to perform simulation analysis first, and then the initial PSA model is updated by the probability theory method to obtain the first PSA model; Perform risk assessment according to the first PSA model to obtain a risk value, and determine whether the risk value is in the risk yellow zone; If you are in the yellow risk zone, then: Establishing a set of alternative solutions, analyzing the set of alternative solutions using a deterministic analysis method, and determining a set of solutions; According to the solution set 1, a probability analysis method is used to analyze to form a solution set 2; According to the second solution set, the optimal solution is obtained.

2. The method according to claim 1, characterized in that: If the collected device status information is a device failure status, the initial PSA model is updated by a probability theory method to obtain a first PSA model, including: The initial PSA model includes an event tree model and / or a fault tree model.

3. The method according to claim 1, characterized in that: If the capability parameter in the collected device performance information decreases, simulation is first performed using a deterministic analysis method, and then the initial PSA model is updated using a probabilistic method to obtain the first PSA model, including: The capability parameters and reliability parameters are input into simulation software to obtain analysis results, and the initial PSA model is updated according to the analysis results in combination with a probability theory method to obtain the first PSA model.

4. The method according to claim 1, characterized in that: The step of performing risk assessment according to the first PSA model to obtain a risk value and determining whether the risk value is in a yellow risk zone includes: The risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value; The first PSA model is input into the analysis software to obtain the risk value, and it is determined whether the risk value is in the risk yellow zone.

5. The method according to claim 4, characterized in that: The risk yellow zone is set to a value greater than / equal to the risk threshold and less than the risk danger value, and also includes: The risk threshold is twice the baseline risk, and the risk danger value is an empirically preset value.

6. The method according to claim 4, characterized in that: Also includes: If it is not in the risk yellow zone, determine whether the risk value is in the risk red zone. The risk red zone is when the risk value is greater than or equal to the risk danger value. If the risk value is in the risk red zone, shut down the reactor immediately.

7. The method according to claim 4, characterized in that: The step of establishing a set of alternative solutions and analyzing the set of alternative solutions using a deterministic analysis method to determine a first set of solutions includes: The set of alternative solutions includes fixed operation solutions for nuclear power units, solutions for switching to other equipment or systems with the same or similar functions, and solutions for power reduction measures; According to the set of alternative solutions, the first PSA model is simulated to obtain a risk indicator set, and the solutions corresponding to the risk indicators in the set of alternative solutions that are lower than the preset indicators are selected from the set of risk indicators to determine solution set one.

8. The method according to claim 7, characterized in that: The corresponding solutions in the set of alternative solutions to the risk index lower than the preset index include: The risk indicator and the preset indicator are both the peak temperature of the reactor core inner cladding.

9. The method according to claim 7, characterized in that: According to the solution set 1, a probability analysis method is used to analyze to form a solution set 2, including: According to the solution set one, the first PSA model is updated to obtain a second PSA model, and the second PSA model is input into the analysis software for risk assessment to obtain a solution risk value set. From the solution risk value set, the solutions corresponding to the solutions in the solution set one whose risk values ​​are lower than the risk threshold are selected to determine the solution set two.

10. The method according to claim 9, characterized in that: The method of obtaining the optimal solution according to the second solution set includes: A weight of one is set for the risk indicator, and a weight of two is set for the risk value of the solution. The risk indicator and the risk value of the solution corresponding to the solution in solution set two are calculated according to the weight of one and the weight of two to obtain a solution score. The best solution is determined according to the solution score and the power in solution set two.

11. A device for autonomous operation decision-making of a nuclear power unit, characterized in that: include: A collection and establishment module, used to collect the equipment status information and equipment performance information of the nuclear power unit through the PHM tool, the equipment status information includes the equipment operation status and the equipment failure status, the equipment performance information includes the capacity parameter, if the collected equipment status information is the equipment failure status, the initial PSA model is updated by the probability theory method to obtain the first PSA model, if the capacity parameter in the collected equipment performance information decreases, the deterministic method is used to perform simulation analysis, and then the initial PSA model is updated by the probability theory method to obtain the first PSA model; A risk assessment module, configured to perform risk assessment according to the first PSA model to obtain a risk value, and determine whether the risk value is in a risk yellow zone; A first determination module is used to establish a set of alternative solutions, analyze the set of alternative solutions using a deterministic analysis method, and determine a set of solutions. The second determination module is used to analyze the solution set 1 using a probability analysis method to form a solution set 2; The decision module is used to obtain the optimal solution according to the second solution set.

12. The device according to claim 11, further characterized in that, in the acquisition establishment module: The initial PSA model includes an event tree model and / or a fault tree model.

13. The device according to claim 11, further characterized in that, in the acquisition establishment module: The capability parameters and reliability parameters are input into simulation software to obtain analysis results, and the initial PSA model is updated according to the analysis results in combination with a probability theory method to obtain the first PSA model.

14. The device according to claim 11, further characterized in that, in the risk assessment module: The risk yellow zone is set to a value between the risk value being greater than / equal to the risk threshold and less than the risk danger value; The first PSA model is input into the analysis software to obtain the risk value, and it is determined whether the risk value is in the risk yellow zone.

15. The device according to claim 14, characterized in that In the risk assessment module: The risk threshold is twice the baseline risk, and the risk danger value is an empirically preset value.

16. The device according to claim 14, further characterized in that, in the risk assessment module: If it is not in the risk yellow zone, determine whether the risk value is in the risk red zone. The risk red zone is when the risk value is greater than or equal to the risk danger value. If the risk value is in the risk red zone, shut down the reactor immediately.

17. The device according to claim 14, further characterized in that, in the first determining module: The set of alternative solutions includes fixed operation of nuclear power units, switching to other equipment or systems with the same or similar functions, and measures to reduce load; According to the alternative solution set, the PSA model of the nuclear power unit is simulated to obtain a risk indicator set, and the solutions corresponding to the risk indicators in the alternative solution set that are lower than the preset indicators are selected from the risk indicator set to determine solution set one.

18. The device according to claim 17, further characterized in that, in the first determining module: The risk indicator and the preset indicator are both the peak temperature of the reactor core inner cladding.

19. The device according to claim 17, further characterized in that, in the second determining module: According to the solution set one, the first PSA model is updated to obtain a second PSA model, and the second PSA model is input into the analysis software for risk assessment to obtain a solution risk value set. From the solution risk value set, the solutions corresponding to the solutions in the solution set one whose risk values ​​are lower than the risk threshold are selected to determine the solution set two.

20. The device according to claim 19, characterized in that In the decision module: A weight of one is set for the risk indicator, and a weight of two is set for the risk value of the solution. The risk indicator and the risk value of the solution corresponding to the solution in solution set two are calculated according to the weight of one and the weight of two to obtain a solution score. The best solution is determined according to the solution score and the power in solution set two.

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