Accident emergency disposal support method suitable for special environment

Abstract

The invention provides an accident emergency disposal support method suitable for a special environment. The accident emergency disposal support method comprises the following steps: step 1, acquiring and preprocessing operation data of a nuclear power device; 2, identifying the operation state of the nuclear power device; 3, the accident state of the nuclear power device is recognized; 4, identifying the safety state of the nuclear power device; 5, quickly predicting the future operation state of the nuclear power device; and step 6, carrying out implementation effect evaluation on the potential human intervention measures. According to the method provided by the invention, a set of online analysis framework aiming at the operation data of the nuclear power device is established, and analysis results such as the operation state, the accident reason, the radioactivity tolerance trend prediction and the intervention evaluation are given. The method can help nuclear accident emergency personnel to build a prospective analysis system, and provides comprehensive technical support for emergency response.

Description

Technical Field

[0001] The present invention relates to the field of nuclear safety and emergency technology, and in particular to an accident emergency handling support method suitable for special environments. Background Art

[0002] In recent years, my country's nuclear power industry has flourished, and coastal nuclear power plants and marine modular small reactors have also been rapidly built. With the increase in nuclear facilities, the risk of nuclear accidents has increased simultaneously. Nuclear accidents are extremely sensitive, have a wide range of impact, and have serious consequences. Compared with nuclear power plants, nuclear power operations in special environments (special conditions refer to marine conditions) will be affected by the sea area, water temperature, seawater flow, meteorology, etc., and are also limited by limited emergency resources and diversified task requirements. Emergency response work is more difficult. Therefore, the need to build support capabilities for accident emergency response in special environments is becoming increasingly prominent. Summary of the invention

[0003] The purpose of the present invention is to provide an accident emergency response support method suitable for special environments, which solves the problem of lack of technical support and forward-looking analysis in the accident response and disposal of nuclear power plants in special environments.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] An accident emergency response support method suitable for special environments, comprising:

[0006] Step 1: Acquire and preprocess nuclear power plant operation data;

[0007] Step 2: Identify the operating status of the nuclear power plant;

[0008] Step 3: Identify the accident status of the nuclear power plant;

[0009] Step 4: Identify the safety status of the nuclear power plant;

[0010] Step 5: Rapidly predict the future operating status of the nuclear power plant;

[0011] Step 6: Evaluate the effectiveness of potential human intervention measures.

[0012] In step 1, the read operation data of the nuclear power plant is checked for validity, including signal unit conversion, checking whether the signal is within the design range, checking the consistency of multiple signal channels, and checking user modification of data; identifying and processing abnormal points includes removing default values ​​and abnormal values, and merging multiple signals.

[0013] Step 2 identifies the operating status of the nuclear power plant through the status analysis module based on the processed operating data, including: the operation of the nuclear power plant under special conditions will cause the internal fluid to be affected by periodically changing additional forces, and change the relative potential difference between the equipment, causing fluctuations in thermal hydraulic parameters, affecting the core flow distribution and power distribution.

[0014] In the identification of special environmental conditions, if there is no direct measurement signal as a reference, it is necessary to judge the periodic change characteristics of the coolant temperature, pressure and flow rate when the nuclear power plant is running stably for reverse inference. Special environmental conditions include:

[0015] Heave motion parameters, i.e., heave motion amplitude and heave motion period;

[0016] Tilt motion working condition parameters, i.e. tilt angle;

[0017] The parameters of the swaying motion condition, namely, the swaying motion amplitude, the swaying motion period and the swaying motion phase;

[0018] Compound motion condition parameters. That is, the superposition of the above parameters.

[0019] Step 3 includes:

[0020] Step 3.1: Identify accident signs, identify the events that occurred within the sampling interval;

[0021] Step 3.2: Accident interval identification: using device operation data and diagnostic models to identify the state interval to which the nuclear accident develops;

[0022] Step 3.3: Identify the cause of the accident, using a diagnostic algorithm based on combining expert knowledge base and fuzzy recognition (existing technology) to analyze the accident signs of the nuclear power plant and provide a diagnosis result of the root cause.

[0023] In step 3.1, accident sign identification includes identifying whether the AC power is lost, the main system water level changes, the main system pressure changes, the reactor compartment (DC) pressure changes, the evaporator water level changes, whether the shutdown protection limit is reached, whether the upper charging and lower discharging are started, and whether the stabilizer heating and spraying are started.

[0024] In step 3.2, the accident area identification includes whether the core is exposed, whether the core is damaged, whether the pressure vessel fails, and whether the reactor compartment fails.

[0025] In step 3.3, the fuzzy expert knowledge base provides accident type judgment rules, and each judgment rule has a matching judgment result. The judgment rule is a series of diagnostic conditions used in the online diagnosis process, and the judgment result is a true / false output of whether the conditions are met. At the same time, fuzzy recognition uses the likelihood function to estimate the probability and replace the original deterministic judgment result.

[0026] Step 4 sets up three typical barriers: fuel cladding, pressure vessel, primary circuit pressure boundary, and reactor compartment. The fault tree-based diagnosis method includes:

[0027] Step 4.1: The fuel cladding status is determined by the reactor compartment emissivity and core outlet temperature parameters;

[0028] Step 4.2: The pressure vessel and the primary circuit pressure boundary are identified by parameters such as leakage and radioactivity monitoring of the primary circuit connection system and the reactor building;

[0029] Step 4.3: The state of the reactor compartment is determined by the parameters such as hydrogen concentration, temperature, and pressure in the reactor compartment.

[0030] In step 5, based on the severe accident simulation model, with the identified nuclear power plant status and accident information as initial conditions, the thermal hydraulic calculation engine is used to rapidly predict the future status of the nuclear power plant and the development of accidents, and to issue targeted warnings for a series of typical events.

[0031] Compared with the prior art, the accident emergency handling support method applicable to special environments provided by the present invention has the following beneficial effects:

[0032] The method provided by the present invention establishes an online analysis framework for the operation data of nuclear power plants, and provides analysis results such as their operation status, accident causes, radioactive containment trend prediction, intervention evaluation, etc. It can help nuclear accident emergency personnel build a forward-looking analysis system and provide comprehensive technical support for emergency response. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A flow chart of an accident emergency handling support method applicable to a special environment provided by the present invention;

[0035] Figure 2 A framework flow chart of the accident emergency handling support method applicable to special environments provided by the present invention;

[0036] Figure 3 This is a flow chart of the rapid prediction calculation provided by the present invention. DETAILED DESCRIPTION

[0037] The following is further explained in detail through specific implementation methods.

[0038] The present invention establishes a data-driven online technical support framework around core functions such as data acquisition, accident diagnosis, operating status, safety margin, and prediction and evaluation. Once an accident occurs in a nuclear power plant, it can help relevant personnel quickly understand the accident status and formulate response measures, effectively establish a forward-looking analysis system, and provide strong technical support for emergency response to accidents.

[0039] like Figure 1 and Figure 2 As shown, the present invention provides an accident emergency handling support method suitable for special environments, comprising the following steps:

[0040] Step 1: Acquire and preprocess nuclear power plant operation data;

[0041] Step 2: Identify the operating status of the nuclear power plant;

[0042] Step 3: Identify the accident status of the nuclear power plant;

[0043] Step 4: Identify the safety status of the nuclear power plant;

[0044] Step 5: Rapidly predict the future operating status of the nuclear power plant;

[0045] Step 6: Evaluate the effectiveness of potential human intervention measures.

[0046] In step 1, the operation data is read and preprocessed through the data communication module, including the following steps:

[0047] Perform validity checks on the operational data of the nuclear power plant read, including signal unit conversion, checking whether the signal is within the design range, checking the consistency of multiple signal channels, and checking user-modified data; identify and process abnormal points, including removing default values ​​and abnormal values, and merging multiple signals.

[0048] In step 2, based on the processed operation data, the operation state of the nuclear power plant is identified by the state analysis module, including the following steps:

[0049] The operation of nuclear power plants under special environments will cause the internal fluid to be affected by periodically changing additional forces, and change the relative potential difference between the equipment, causing fluctuations in thermal hydraulic parameters, affecting the core flow distribution and power distribution. Therefore, in order to identify special environmental conditions, if there are direct parameters as a reference, it is necessary to judge the periodic change characteristics of the coolant temperature, pressure and flow when the nuclear power plant is running stably, and make reverse inferences, giving the following special environmental conditions:

[0050] (1) Heaving motion parameters, i.e., heaving motion amplitude and heaving motion period;

[0051] (2) Tilt motion parameters, i.e., tilt angle;

[0052] (3) Sway motion parameters, i.e., sway motion amplitude, sway motion period, and sway motion phase;

[0053] (4) Composite motion condition parameters.

[0054] In step 3, based on the processed operation data, the accident state of the nuclear power plant is identified through the state analysis module, including the following steps:

[0055] Step 3.1: Identification of accident signs, identifying events that occurred within the sampling interval, including whether AC power is lost, main system water level changes, main system pressure changes, reactor compartment (DC) pressure changes, evaporator water level changes, whether the shutdown protection limit is reached, whether the upper charging and lower discharging are activated, whether the stabilizer heating and spraying are activated, etc.

[0056] Step 3.2: Accident interval identification is to identify the state interval to which the nuclear accident develops based on the device operation data and diagnostic models, such as whether the core is exposed, whether the core is damaged, whether the pressure vessel fails, whether the reactor compartment fails, etc.

[0057] Step 3.3: Identify the cause of the accident. Use the fuzzy expert knowledge base (based on the diagnosis algorithm combining the expert knowledge base and fuzzy recognition) to analyze the accident signs of the nuclear power plant and give the diagnosis result of the root cause, that is, identify the specific type of accident. The expert knowledge base provides the judgment rules of the accident type, and each judgment rule has a judgment result of whether it matches. The judgment rule is a series of diagnostic conditions used in the online diagnosis process, and the judgment result is the output of whether the condition is met (true / false). At the same time, fuzzy recognition uses the likelihood function to estimate the probability and replace the original deterministic judgment result.

[0058] In step 4, based on the processed operating data, the safety status of the nuclear power plant is identified, that is, the shielding capability of the nuclear power plant against radioactive materials to prevent the release of radioactive materials into the environment in nuclear accidents. According to the principle of defense in depth, three typical barriers are mainly set up, namely, the fuel cladding, the pressure vessel and the primary circuit pressure boundary, and the reactor compartment. The fault tree-based diagnosis method includes the following steps:

[0059] Step 4.1: The fuel cladding status is determined by the DC radiation rate and the core outlet temperature parameters, including three different states: intact, in crisis, and at risk of damage;

[0060] Step 4.2: The pressure vessel and the primary circuit pressure boundary are identified through parameters such as leakage and radioactivity monitoring of the primary circuit connection system and the reactor building, including three different states: intact, in crisis, and at risk of damage;

[0061] Step 4.3: The state of the compartment is determined by the parameters such as hydrogen concentration, temperature, and pressure in the compartment, including three different states: intact, in crisis, and at risk of damage.

[0062] In step 5, based on the severe accident simulation model and based on the identified nuclear power plant status and accident information as initial conditions, the thermal hydraulic calculation engine is used to quickly predict the future status and accident development of the nuclear power plant, and can provide targeted warnings for a series of typical events, such as core exposure, steam generator burnout, and loss of reactor cooling capacity.

[0063] The safety margin assessment is based on the current status and prediction results of the nuclear power plant, and takes into account the external environmental parameters, available emergency resources, and the investment in safety facilities. It gives the margin assessment values ​​of the nuclear power plant in the short term (<30 minutes), medium term (30 minutes-1 hour), and long term (>1 hour), and determines whether there is a risk of safety margin reduction.

[0064] In step 6, if Figure 3 As shown in the figure, in the rapid prediction calculation process, the initial state is used as the starting point, the state file of the nuclear power device is read, and the calculation engine is initialized by multi-threaded parallel computing according to the modeling uncertainty to achieve the prediction of future accident evolution. It also supports the insertion of potential intervention plans, thereby affecting the subsequent development of accidents. The relevant prediction analysis results can provide technical support for accident emergency response under special circumstances.

[0065] The present invention also provides an accident emergency response support system suitable for special environments, which realizes core functions such as status analysis, accident diagnosis, and prediction and evaluation, establishes a data-driven online technical support framework, and helps emergency personnel build a forward-looking analysis system. The system includes the following modules:

[0066] Data communication module: acquire and process the operation data of nuclear power plant;

[0067] State analysis module: identifies the operating state, accident state and safety state of nuclear power plants;

[0068] Rapid prediction module: Rapidly predict the future operating status of nuclear power plants;

[0069] Intervention Evaluation Module: Supports the evaluation of the implementation effects of potential human intervention measures in predictive calculations.

[0070] Among them, the state analysis module identifies the operating state, accident state and safety state of the device based on the state diagnosis model; the rapid prediction module uses the fast time rate characteristics of the calculation engine and uses the identified device state and accident information as initial conditions to perform advance calculation and analysis on the future accident development trend of the device. The intervention evaluation module supports the introduction of intervention measures in the prediction calculation and evaluates their implementation effect. The functions realized by the accident emergency response support method suitable for special environments are similar to other evaluation and prediction methods.

[0071] The present invention obtains the real-time operation data of the device from the nuclear power device information system, and after data preprocessing, uses it as input data to drive the identification of the overall state of the device. It mainly uses the fuzzy expert knowledge base to diagnose the three aspects of operation state, accident state and safety state, and provides information such as the initiating event, equipment action and safety margin. The severe accident analysis program is used as the calculation engine for predictive calculation, and the initiating event information is used as the initial condition. Its fast-time multiplier characteristics are used to quickly predict the future state of the device. The accident emergency response support method under special environment not only takes the control of radioactive material release as the fundamental safety goal, but also considers factors such as external environment, mission tasks, and continuous power requirements in the analysis process.

[0072] This method can use device signals as input to drive analysis of operating status, accident causes, safety margins, etc., and predict future accident developments to support emergency response to accidents.

[0073] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An accident emergency handling support method suitable for special environments, characterized in that: include: Step 1: Acquire and preprocess nuclear power plant operation data; Step 2: Identify the operating status of the nuclear power plant; Step 3: Identify the accident status of the nuclear power plant; Step 4: Identify the safety status of the nuclear power plant; Step 5: Rapidly predict the future operating status of the nuclear power plant; Step 6: Evaluate the effectiveness of potential human intervention measures.

2. The accident emergency handling support method applicable to special environments according to claim 1 is characterized in that: In step 1, the read operation data of the nuclear power plant is checked for validity, including signal unit conversion, checking whether the signal is within the design range, checking the consistency of multiple signal channels, and checking user modification of data; identifying and processing abnormal points includes removing default values ​​and abnormal values, and merging multiple signals.

3. The accident emergency handling support method applicable to special environments according to claim 1 is characterized in that: Step 2 identifies the operating status of the nuclear power plant through the status analysis module based on the processed operating data, including: the operation of the nuclear power plant under special conditions will cause the internal fluid to be affected by periodically changing additional forces, and change the relative potential difference between the equipment, causing fluctuations in thermal hydraulic parameters, affecting the core flow distribution and power distribution.

4. The accident emergency handling support method applicable to special environments according to claim 3 is characterized in that: In the identification of special environmental conditions, if there is no direct measurement signal as a reference, it is necessary to judge the periodic change characteristics of the coolant temperature, pressure and flow rate when the nuclear power plant is running stably for reverse inference. Special environmental conditions include: Heave motion parameters, i.e., heave motion amplitude and heave motion period; Tilt motion working condition parameters, i.e. tilt angle; The parameters of the swaying motion condition, namely, the swaying motion amplitude, the swaying motion period and the swaying motion phase; Composite motion condition parameters.

5. The accident emergency handling support method applicable to special environments according to claim 1, characterized in that: Step 3 includes: Step 3.1: Identify accident signs, identify the events that occurred within the sampling interval; Step 3.2: Accident interval identification: using device operation data and diagnostic models to identify the state interval to which the nuclear accident develops; Step 3.3: Identification of the cause of the accident. Analyze the accident signs of the nuclear power plant using a diagnostic algorithm based on the combination of expert knowledge base and fuzzy recognition, and provide the diagnosis results of the root cause.

6. The accident emergency handling support method applicable to special environments according to claim 5, characterized in that: In step 3.1, accident sign identification includes identifying whether the AC power is lost, the main system water level changes, the main system pressure changes, the reactor compartment pressure changes, the evaporator water level changes, whether the shutdown protection limit is reached, whether the upper charging and lower discharging are started, and whether the stabilizer heating and spraying are started.

7. The accident emergency handling support method applicable to special environments according to claim 5, characterized in that: In step 3.2, the accident area identification includes whether the core is exposed, whether the core is damaged, whether the pressure vessel fails, and whether the reactor compartment fails.

8. The accident emergency handling support method applicable to special environments according to claim 5, characterized in that: In step 3.3, the fuzzy expert knowledge base provides accident type judgment rules, and each judgment rule has a matching judgment result. The judgment rule is a series of diagnostic conditions used in the online diagnosis process, and the judgment result is a true / false output of whether the conditions are met. At the same time, fuzzy recognition uses the likelihood function to estimate the probability and replace the original deterministic judgment result.

9. The accident emergency handling support method applicable to special environments according to claim 1, characterized in that: Step 4 sets up three typical barriers: fuel cladding, pressure vessel, primary circuit pressure boundary, and reactor compartment. The fault tree-based diagnosis method includes: Step 4.1: The fuel cladding status is determined by the reactor compartment emissivity and core outlet temperature parameters; Step 4.2: The pressure vessel and the primary circuit pressure boundary are identified by parameters such as leakage and radioactivity monitoring of the primary circuit connection system and the reactor building; Step 4.3: The state of the reactor compartment is determined by the parameters such as hydrogen concentration, temperature, and pressure in the reactor compartment.

10. The accident emergency handling support method applicable to special environments according to claim 1, characterized in that: In step 5, based on the severe accident simulation model, with the identified nuclear power plant status and accident information as initial conditions, the thermal hydraulic calculation engine is used to rapidly predict the future status of the nuclear power plant and the development of accidents, and to issue targeted warnings for a series of typical events.

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