Accident handling method and system for abnormal pressure in containment of small pressurized water reactor

Abstract

The present invention provides a method and system for handling an abnormal pressure accident in a small pressurized water reactor containment, the method comprising: determining the type of the abnormal pressure condition to be analyzed, obtaining the type of condition to which the condition type belongs, and then obtaining the corresponding handling strategy according to the condition category, and executing the handling strategy. The present invention designs a reasonable multi-level handling strategy for abnormal pressure conditions in the containment based on the design characteristics of a small pressurized water reactor, and improves the handling strategy for abnormal pressure conditions in the containment from the perspective of diversity of measures and defense in depth, thereby achieving the effect of maximizing the operating environment in the containment, controlling the development of accident conditions, and mitigating the consequences of accidents.

Description

Technical Field

[0001] The present invention specifically relates to a method and system for handling an accident of abnormal pressure in a containment vessel of a small pressurized water reactor. Background Art

[0002] Usually, the reactor loaded with nuclear fuel and the system equipment containing the primary coolant in direct contact with the nuclear fuel are arranged in the containment. This design makes it possible to limit the accidents that may cause the release of radioactive materials within the containment. The containment acts as the last barrier of the nuclear power plant to prevent the release of radioactive materials into the environment. According to the principle of defense in depth, it is required to ensure the containment function under various working conditions, especially after the emergency shutdown action that indicates the occurrence of an accident is triggered.

[0003] With the safety of the reactor located in the containment as the center and the safety of the last barrier as the basis, the important systems and equipment responses of nuclear power plants all act on the containment. The relevant failures or accident consequences may affect or damage the function of the containment, such as the good condition of the containment, the sealing of the containment, the strength of the containment, etc. In the system design, the focus is on maintaining the integrity of the containment under accident conditions and avoiding radioactive contamination of the external environment, which is the basic requirement of nuclear safety. However, after different accidents, the response of the atmosphere in the containment is different. The containment safety cannot be guaranteed by the containment cooling system only conservatively. The following situations must also be considered: for example, containment isolation to prevent leakage, temperature increase in the containment, pressure increase in the containment to challenge the containment strength, hydrogen accumulation risk in the containment, damp heat in the containment affecting the working conditions of the equipment, high radioactive environment deterioration in the containment, containment isolation and leakage. In order to improve the safety and operational response of the containment, systems and equipment that are beneficial to the state of the containment should be comprehensively applied according to the method.

[0004] Failures or accidents in small pressurized water reactor nuclear power plants may cause abnormal pressure in the containment, affect or damage the containment function, so the causes of containment accident conditions are complex and diverse. The direct consequence of abnormal pressure conditions caused by containment accidents is to challenge the containment function. Therefore, abnormal pressure conditions in the containment need to be handled in a timely manner to improve the operating environment of the containment and prevent the evolution from causing adverse consequences. Compared with large commercial pressurized water reactors, small pressurized water reactors have lower mass-energy release in accidents. Combined with the characteristics of operating power plant design and system design, there are differences in the design of related system equipment such as core and primary circuit, containment and dedicated safety system. In order to simplify the post-accident response and improve the passive safety of small pressurized water reactor nuclear power plants, a normally open passive air cooling system is designed, which relies on the outer surface of the steel shell to cool by convection, radiation and heat conduction through the naturally circulating cold air. From a safety perspective, this meets the requirements. But it also brings new challenges. For example, the passive containment cooling method has the problem that the pressure and temperature of the containment drop slowly in the long process after the accident, and it is maintained in a high pressure and temperature range for a long time. Therefore, in the system design, different treatment measures are used in small pressurized water reactors according to different operating conditions: for design basis accidents, the passive containment cooling system is mainly relied on, and a containment external spray system is designed to enhance cooling; for severe accidents, a containment internal fire water spray system is set up. In this way, the diversified and multi-mode design of system measures brings new problems such as how to combine them for effective treatment.

[0005] In order to solve the abnormal pressure inside the containment after the accident and avoid degradation of the third barrier function, it is necessary to design a reasonable post-accident containment depressurization and cooling accident handling strategy in combination with the design of the small pressurized water reactor system. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for handling abnormal pressure accidents of a small pressurized water reactor containment vessel in combination with a small pressurized water reactor system design scheme in view of the above-mentioned deficiencies in the prior art, thereby improving the operating environment conditions of the containment vessel and avoiding degradation of the third barrier function.

[0007] The technical solution adopted to solve the technical problem of the present invention is:

[0008] The present invention provides a method for handling an accident of abnormal pressure in a containment vessel of a small pressurized water reactor, comprising:

[0009] Determine the working condition type of the abnormal pressure working condition to be analyzed, obtain the working condition category to which the working condition type belongs, and then obtain the corresponding processing strategy according to the working condition category, and execute the processing strategy.

[0010] Optionally,

[0011] When the containment pressure is higher than the maximum pressure value of the containment in normal operation and is less than or equal to the abnormally high containment pressure setting value, and the duration is less than or equal to the first setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_10.

[0012] When the containment pressure is higher than the maximum pressure value of the containment in normal operation and is less than or equal to the abnormally high containment pressure setting value, and the duration is longer than the first setting value, the type of abnormal pressure condition to be analyzed is cond_11.

[0013] When the containment pressure is higher than the abnormal high pressure setting value and is less than or equal to the warning value, and the duration is less than or equal to the second setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_20, and the warning value is close to and less than or equal to the containment design pressure value.

[0014] When the containment pressure is higher than the abnormally high pressure setting value and is less than or equal to the warning value, and the duration is longer than the second setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_21.

[0015] When the containment pressure is higher than the warning value and less than or equal to the containment design pressure value, and the duration is less than or equal to the third set value, the type of the abnormal pressure condition to be analyzed is judged to be cond_22.

[0016] When the containment pressure is higher than the warning value and less than or equal to the containment design pressure value, and the duration is longer than the third set value, the type of the abnormal pressure condition to be analyzed is judged to be cond_23.

[0017] When the containment pressure is higher than the containment design pressure value, the type of abnormal pressure condition to be analyzed is judged to be cond_30.

[0018] When the small pressurized water reactor is in a severe accident condition and the power plant enters the severe accident management procedure, the type of abnormal pressure condition to be analyzed is judged to be cond_40.

[0019] Optionally, the operating condition category to which the type belongs is obtained according to a mapping table, the mapping table comprising:

[0020] The working condition type cond_10 belongs to the working condition category A.

[0021] The working condition types cond_11 and cond_20 are classified in the working condition category B.

[0022] The operating conditions cond_21, cond_22, cond_23 and cond_30 are classified in the C operating condition category.

[0023] The operating condition type cond_40 is classified in the D type operating condition category.

[0024] Optionally, for the Class A working condition category, the corresponding processing strategies include:

[0025] Continue to determine the type of the abnormal pressure condition to be analyzed, as well as the category to which the condition type belongs. When the category to which it belongs is changed to Category B, execute the processing strategy corresponding to Category B. When it is changed to normal conditions, stop processing this abnormal pressure accident.

[0026] Optionally, for the Class B working condition category, the corresponding processing strategies include:

[0027] Confirm containment isolation,

[0028] Obtain the pressure and temperature change trends of the containment, evaluate the cooling effect of the passive containment, and start the internal ventilation system of the containment when the cooling effect does not meet the criteria.

[0029] Continuously determine the working condition type of the abnormal pressure working condition to be analyzed, as well as the working condition category to which the working condition type belongs. When the working condition category to which it belongs is changed to Class A working condition category, execute the processing strategy corresponding to Class A working condition category. When the working condition category to which it belongs is changed to Class C working condition category, execute the processing strategy corresponding to Class C working condition category.

[0030] Optionally, for the C-type working condition category, the corresponding processing strategy includes:

[0031] Confirm containment isolation,

[0032] Confirm that the passive containment cooling system is operating normally,

[0033] Isolate the source of mass and energy release within the containment,

[0034] Start the external spraying of containment.

[0035] Continuously determine the operating condition type of the abnormal pressure condition to be analyzed and the operating condition category to which the operating condition type belongs. When the operating condition category to which it belongs is changed to Class B operating condition category, shut down the external spraying of the containment and execute the processing strategy corresponding to Class B operating condition category. When the operating condition category to which it belongs is changed to Class D operating condition category, execute the processing strategy corresponding to Class D operating condition category.

[0036] Optionally, for the C-type working condition category, the corresponding processing strategy also includes:

[0037] Monitor the temperature inside the containment. If the internal refueling water tank cannot be cooled by the normal waste heat removal system and equipment cooling water, the external shell spray system and the passive containment cooling system will be used as the long-term heat sink of the internal refueling water tank.

[0038] Optionally, for the D-type working condition category, the corresponding processing strategy includes:

[0039] Confirm containment isolation,

[0040] Start the external spraying of containment.

[0041] Continue to judge the operating condition type of the abnormal pressure condition to be analyzed and the operating condition category to which the operating condition type belongs. When the operating condition category to which it belongs is changed to Class C operating condition category, execute the processing strategy corresponding to Class C operating condition category. When the operating condition category to which it belongs is still Class D operating condition category, start internal spraying of the containment.

[0042] The present invention also provides a system for implementing the above-mentioned method for handling the accident of abnormal pressure in the containment of a small pressurized water reactor, comprising:

[0043] The judgment module is used to judge the type of the abnormal pressure condition to be analyzed.

[0044] The first acquisition module is connected to the judgment module and is used to obtain the operating condition category to which the operating condition type belongs.

[0045] The second acquisition module is connected to the first acquisition module and is used to acquire the corresponding processing strategy according to the working condition category.

[0046] An execution module is connected to the second acquisition module and is used to execute the processing strategy.

[0047] Optionally, a storage module is further included, in which a mapping relationship between each operating condition type and each operating condition category is stored, and a processing strategy corresponding to each operating condition category is also stored.

[0048] The present invention designs a reasonable multi-level containment pressure abnormal condition processing strategy based on the design characteristics of the small pressurized water reactor, and improves the accident processing strategy for the containment pressure abnormal condition from the perspective of measure diversity and in-depth defense, so as to maximize the improvement of the operating environment inside the containment, control the development of accident conditions, and mitigate the consequences of accidents.

[0049] The accident handling strategy designed in the present invention can be used to comprehensively deal with various abnormal containment pressure conditions of small pressurized water reactors, can cover the range of operating conditions from deviations from normal operation to designed extended conditions, and provides a systematic response plan.

[0050] The present invention can be used to guide the design and optimization of accident handling procedure documents related to accident conditions in the containment of a small pressurized water reactor, and can improve the accident procedures for handling accident conditions in the containment from the perspectives of strategy and measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is an analysis flow chart of the accident handling method for abnormal containment pressure of a small pressurized water reactor provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0052] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0053] In the description of the present invention, it should be noted that the directions or positional relationships indicated by “upper” and the like are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the system or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0054] In the description of the present invention, the terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0055] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] The present invention provides a method for handling an accident of abnormal pressure in a containment vessel of a small pressurized water reactor, comprising:

[0057] Determine the working condition type of the abnormal pressure working condition to be analyzed, obtain the working condition category to which the working condition type belongs, and then obtain the corresponding processing strategy according to the working condition category, and execute the processing strategy.

[0058] The present invention also provides a system for implementing the above-mentioned method for handling the accident of abnormal pressure in the containment of a small pressurized water reactor, comprising:

[0059] The judgment module is used to judge the type of the abnormal pressure condition to be analyzed.

[0060] The first acquisition module is connected to the judgment module and is used to obtain the operating condition category to which the operating condition type belongs.

[0061] The second acquisition module is connected to the first acquisition module and is used to acquire the corresponding processing strategy according to the working condition category.

[0062] An execution module is connected to the second acquisition module and is used to execute the processing strategy.

[0063] Embodiment 1:

[0064] like Figure 1 As shown, this embodiment provides a method for handling an accident of abnormal pressure in a containment vessel of a small pressurized water reactor, comprising:

[0065] Determine the working condition type of the abnormal pressure working condition to be analyzed, obtain the working condition category to which the working condition type belongs, and then obtain the corresponding processing strategy according to the working condition category, and execute the processing strategy.

[0066] By obtaining the pressure trend of the small pressurized water reactor containment, the type of abnormal pressure condition to be analyzed can be determined, specifically:

[0067] When the containment pressure is higher than the maximum pressure value of the containment in normal operation and is less than or equal to the abnormally high containment pressure setting value, and the duration is less than or equal to the first setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_10.

[0068] When the containment pressure is higher than the maximum pressure value of the containment in normal operation and is less than or equal to the abnormally high containment pressure setting value, and the duration is longer than the first setting value, the type of abnormal pressure condition to be analyzed is cond_11.

[0069] When the containment pressure is higher than the abnormal high pressure setting value and is less than or equal to the warning value, and the duration is less than or equal to the second setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_20, and the warning value is close to and less than or equal to the containment design pressure value.

[0070] When the containment pressure is higher than the abnormally high pressure setting value and is less than or equal to the warning value, and the duration is longer than the second setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_21.

[0071] When the containment pressure is higher than the warning value and less than or equal to the containment design pressure value, and the duration is less than or equal to the third set value, the type of the abnormal pressure condition to be analyzed is judged to be cond_22.

[0072] When the containment pressure is higher than the warning value and less than or equal to the containment design pressure value, and the duration is longer than the third set value, the type of the abnormal pressure condition to be analyzed is judged to be cond_23.

[0073] When the containment pressure is higher than the containment design pressure value, the type of abnormal pressure condition to be analyzed is judged to be cond_30.

[0074] When the small pressurized water reactor is in a severe accident condition and the power plant enters the severe accident management procedure, the type of abnormal pressure condition to be analyzed is judged to be cond_40.

[0075] That is, the present invention defines the conditions related to the abnormal operating conditions of the containment pressure of the small pressurized water reactor nuclear power plant as follows:

[0076] cond_10: The containment pressure is higher than the normal operating pressure range of the containment

[0077] cond_11: The duration of cond_10 is greater than the specified value of the nuclear power plant

[0078] cond_20: containment pressure is higher than the set value of abnormally high containment pressure

[0079] cond_21: Small pressurized water reactor nuclear power plant is in the long-term recovery stage after the accident

[0080] cond_22: The containment pressure is higher than the warning value close to the design pressure

[0081] cond_23: The duration of cond_20 is greater than the specified value of the nuclear power plant

[0082] cond_30: containment pressure is higher than the design pressure

[0083] cond_40: The power plant is in a severe accident condition and enters the severe accident management procedure.

[0084] Among them, the relevant pressure constants and time length constants are determined based on the constants of the containment design and system design of the actual small pressurized water reactor nuclear power plant.

[0085] In this embodiment, see Table 1 for details. In order to take appropriate treatment measures in a targeted manner, the abnormal containment pressure conditions are divided into four categories. The condition category to which the type belongs is obtained according to the mapping table. The mapping table includes:

[0086] The working condition type cond_10 belongs to the working condition category A.

[0087] The working condition types cond_11 and cond_20 are classified in the working condition category B.

[0088] The operating conditions cond_21, cond_22, cond_23 and cond_30 are classified in the C operating condition category.

[0089] The operating condition type cond_40 is classified in the D type operating condition category.

[0090] Table 1

[0091]

[0092]

[0093] After determining the working conditions inside the containment according to the conditions, select the appropriate strategy to implement. The following are the treatment strategies adopted in various abnormal pressure conditions of the containment.

[0094] In this embodiment, for the Class A working condition category, the corresponding processing strategies include:

[0095] Continue to determine the type of the abnormal pressure condition to be analyzed, as well as the category to which the condition type belongs. When the category to which it belongs is changed to Category B, execute the processing strategy corresponding to Category B. When it is changed to normal conditions, stop processing this abnormal pressure accident.

[0096] In this embodiment, for the Class B working condition category, the corresponding processing strategies include:

[0097] Confirm containment isolation,

[0098] Obtain the pressure and temperature change trends of the containment, evaluate the cooling effect of the passive containment, and start the internal ventilation system of the containment when the cooling effect does not meet the criteria.

[0099] Continuously judge the working condition type of the abnormal pressure working condition to be analyzed and the working condition category to which the working condition type belongs. When the working condition category to which it belongs is changed to Class A working condition category, execute the processing strategy corresponding to Class A working condition category. When the working condition category to which it belongs is changed to Class C working condition category, execute the processing strategy corresponding to Class C working condition category.

[0100] The criteria for judging the above-mentioned passive containment cooling effect are: the containment pressure and temperature return to the normal operating range within the specified time of the power plant, or the passive containment cooling system is deemed to be working well based on the power plant system design and the containment is in a trend of reducing pressure and temperature: the containment pressure returns to below 6kPa.g or the temperature gradient in the containment changes to a negative value over time.

[0101] In addition, the external air flow state and air temperature of the passive containment cooling system can also be used as joint evaluation indicators to evaluate the containment cooling effect.

[0102] In this embodiment, for the C-type working condition category, the corresponding processing strategy includes:

[0103] Confirm containment isolation,

[0104] The passive containment cooling system is operating normally through joint evaluation indicators such as the pressure and temperature change trends of the containment and the external air flow status of the passive containment cooling system.

[0105] Check and isolate the source of mass and energy release in the containment, isolate the abnormal water supply and steam circuits in the containment,

[0106] Start the external spraying of the containment to enhance the depressurization and cooling effect of the containment.

[0107] Continuously determine the operating condition type of the abnormal pressure condition to be analyzed and the operating condition category to which the operating condition type belongs. When the operating condition category to which it belongs is changed to Class B operating condition category, shut down the external spraying of the containment and execute the processing strategy corresponding to Class B operating condition category. When the operating condition category to which it belongs is changed to Class D operating condition category, execute the processing strategy corresponding to Class D operating condition category.

[0108] In this embodiment, for the C-type working condition category, the corresponding processing strategy also includes:

[0109] Monitor the temperature inside the containment. If the internal refueling water tank cannot be cooled by the normal waste heat removal system and equipment cooling water, the external shell spray system and the passive containment cooling system will be used as the long-term heat sink of the internal refueling water tank.

[0110] The water tank of the external shell spray system is continuously filled with water to meet its requirement as a long-term heat sink for the internal refueling water tank.

[0111] In this embodiment, for the D-type working condition category, the corresponding processing strategy includes:

[0112] Confirm containment isolation,

[0113] Start the external spraying of the containment to enhance the depressurization and cooling effect of the containment.

[0114] Continue to judge the operating condition type of the abnormal pressure condition to be analyzed, as well as the operating condition category to which the operating condition type belongs. When the operating condition category to which it belongs is changed to Class C operating condition category, execute the processing strategy corresponding to Class C operating condition category. When the operating condition category to which it belongs is still Class D operating condition category, start internal spraying of the containment to assist in reducing the pressure and temperature inside the containment.

[0115] In summary, the present invention proposes a multi-level post-accident containment pressure reduction and cooling method for the treatment of abnormal containment pressure conditions, combining ventilation, passive containment cooling, containment external spraying, and containment internal spraying to form a set of strategic methods. The following problems are mainly solved:

[0116] 1) Determine the classification of abnormal containment pressure conditions of small pressurized water reactor nuclear power plants;

[0117] 2) Determine applicable accident handling strategies for various abnormal containment pressure conditions of small pressurized water reactors.

[0118] The present invention has the following application effects:

[0119] 1. Based on the design characteristics of small pressurized water reactors, a reasonable multi-level containment pressure abnormality handling strategy is designed. The accident handling strategy for containment pressure abnormality conditions is improved from the perspective of measure diversity and in-depth defense, so as to maximize the operating environment inside the containment, control the development of accident conditions, and mitigate the consequences of accidents.

[0120] 2. The accident handling strategy designed in the present invention can be used to comprehensively deal with various abnormal containment pressure conditions of small pressurized water reactors, and can cover the range of operating conditions from deviations from normal operation to designed extended conditions, providing a systematic response plan.

[0121] 3. The present invention can be used to guide the design and optimization of accident handling procedure documents related to accident conditions in the containment of a small pressurized water reactor, and can improve the accident procedures for handling accident conditions in the containment from the perspectives of strategy and measures.

[0122] The following explanation is given using an example of the high-pressure operating conditions of the containment of a small pressurized water reactor project.

[0123] (1) Classification of abnormal containment pressure conditions

[0124] Combined with the actual design of the small pressurized water reactor project, the abnormal pressure condition of the containment is defined as follows:

[0125] cond_10: containment pressure is higher than 6kPa.g

[0126] cond_11: The duration of cond_10 is greater than 2 hours

[0127] cond_20: containment pressure is higher than 0.02MPa.g

[0128] cond_21: Small pressurized water reactor nuclear power plant is in the long-term recovery stage after the accident

[0129] cond_22: containment pressure is higher than 0.18MPa.g

[0130] cond_23: The duration in cond_20 is greater than 2h

[0131] cond_30: containment pressure is higher than 0.36MPa.g

[0132] cond_40: In severe accident condition, the power plant enters severe accident management procedure

[0133] Corresponding classification of abnormal containment pressure conditions:

[0134] Class A working conditions

[0135] The containment pressure is higher than 6kPa.g and lower than 0.02MPa.g, and lasts for less than 2 hours.

[0136] Type B working condition

[0137] The containment pressure is higher than 6kPa.g and lower than 0.02MPa.g, and lasts for more than 2h;

[0138] Or, the containment pressure is higher than 0.02MPa.g and lower than 0.18MPa.g, and lasts for less than 2 hours, and there are no other special circumstances.

[0139] Type C working condition

[0140] The containment pressure is higher than 0.02MPa.g and lower than 0.18MPa.g, and lasts for more than 2 hours. The small pressurized water reactor nuclear power plant is in the long-term recovery stage after the accident;

[0141] Or, the containment pressure is higher than 0.18MPa.g and lower than 0.36MPa.g, and the duration is less than 2 hours;

[0142] Or, the containment pressure is higher than 0.02MPa.g and lower than 0.36MPa.g, and lasts for more than 2 hours;

[0143] Or, the containment pressure is higher than 0.36MPa.g.

[0144] Class D working conditions

[0145] The power plant is in a severe accident condition.

[0146] (2) Strategies for handling various working conditions

[0147] After distinguishing various working conditions, enter the corresponding strategies below and take measures to deal with them:

[0148] Class A working conditions

[0149] Relying on passive containment cooling effect to restore containment pressure;

[0150] Pay attention to the changing trends of containment pressure and temperature.

[0151] Type B working condition

[0152] Confirm containment isolation;

[0153] Focus on containment pressure and temperature and evaluate the effectiveness of passive containment cooling;

[0154] If passive containment cooling is less effective, use the containment internal ventilation system;

[0155] Continuously monitor the containment pressure. If it turns to Class A conditions, implement the Class A condition handling strategy. If it turns to Class C conditions, implement the Class C condition handling strategy.

[0156] Type C working condition

[0157] Confirm containment isolation;

[0158] Confirm that the passive containment cooling system is operating;

[0159] Commissioning of external containment spraying to maintain simultaneous operation with the passive containment cooling system;

[0160] Continuously monitor the containment pressure. If it changes to Class B conditions, implement the Class B condition handling strategy. If it changes to Class D conditions, implement the Class D condition handling strategy.

[0161] When the containment pressure returns to below 0.02MPa.g, the external spraying of the containment will be shut down.

[0162] Class D working conditions

[0163] Confirm containment isolation;

[0164] External spraying of the containment vessel during commissioning;

[0165] The containment pressure is continuously monitored and if it changes to Class C operating conditions, the internal spraying of the containment is put into operation.

[0166] Embodiment 2:

[0167] This embodiment provides a system for implementing the accident handling method for abnormal pressure of a small pressurized water reactor containment vessel of embodiment 1, comprising:

[0168] The judgment module is used to judge the type of the abnormal pressure condition to be analyzed.

[0169] The first acquisition module is connected to the judgment module and is used to obtain the working condition category to which the working condition type belongs.

[0170] The second acquisition module is connected to the first acquisition module and is used to acquire the corresponding processing strategy according to the working condition category.

[0171] The execution module is connected to the second acquisition module and is used for executing the processing strategy.

[0172] In this embodiment, a storage module is further included, in which a mapping relationship between each operating condition type and each operating condition category is stored, and a processing strategy corresponding to each operating condition category is also stored.

[0173] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for handling an abnormal pressure accident in a small pressurized water reactor containment vessel, characterized in that: include: Determine the working condition type of the abnormal pressure working condition to be analyzed, obtain the working condition category to which the working condition type belongs, and then obtain the corresponding processing strategy according to the working condition category, and execute the processing strategy; When the containment pressure is higher than the maximum pressure value of the containment in normal operation and is less than or equal to the abnormally high containment pressure setting value, and the duration is less than or equal to the first setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_10. When the containment pressure is higher than the maximum pressure value of the containment in normal operation and is less than or equal to the abnormally high containment pressure setting value, and the duration is longer than the first setting value, the type of abnormal pressure condition to be analyzed is cond_11. When the containment pressure is higher than the abnormal high pressure setting value and is less than or equal to the warning value, and the duration is less than or equal to the second setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_20, and the warning value is close to and less than or equal to the containment design pressure value. The operating condition category to which the type belongs is obtained according to a mapping table, wherein the mapping table includes: The working condition type cond_10 belongs to the working condition category A. The working condition types cond_11 and cond_20 are classified in the working condition category B. For Class A working conditions, the corresponding processing strategies include: Continuously determine the type of the abnormal pressure condition to be analyzed and the category to which the abnormal pressure condition belongs. When the category to which the abnormal pressure condition belongs is changed to the category B, execute the processing strategy corresponding to the category B. When it is changed to the normal condition, stop processing the abnormal pressure accident. For Class B working conditions, the corresponding processing strategies include: Confirm containment isolation, Obtain the pressure and temperature change trends of the containment, evaluate the cooling effect of the passive containment, and start the internal ventilation system of the containment when the cooling effect does not meet the criteria. Continuously determine the working condition type of the abnormal pressure working condition to be analyzed and the working condition category to which the working condition type belongs, and when the working condition category to which it belongs is changed to the Class A working condition category, execute the processing strategy corresponding to the Class A working condition category; The criteria are: the containment pressure and temperature return to the normal operating range within the time specified by the power plant, or according to the power plant system design, it is determined that the passive containment cooling system works well and the containment is in a trend of reducing pressure and temperature.

2. The method for handling an accident of abnormal pressure in a small pressurized water reactor containment vessel according to claim 1, characterized in that: When the containment pressure is higher than the abnormally high pressure setting value and is less than or equal to the warning value, and the duration is longer than the second setting value, the type of the abnormal pressure condition to be analyzed is judged to be cond_21. When the containment pressure is higher than the warning value and less than or equal to the containment design pressure value, and the duration is less than or equal to the third set value, the type of the abnormal pressure condition to be analyzed is judged to be cond_22. When the containment pressure is higher than the warning value and less than or equal to the containment design pressure value, and the duration is longer than the third set value, the type of the abnormal pressure condition to be analyzed is judged to be cond_23. When the containment pressure is higher than the containment design pressure value, the type of abnormal pressure condition to be analyzed is judged to be cond_30. When the small pressurized water reactor is in a severe accident condition and the power plant enters the severe accident management procedure, the type of abnormal pressure condition to be analyzed is judged to be cond_40.

3. The method for handling an abnormal pressure accident of a small pressurized water reactor containment vessel according to claim 2, characterized in that: The operating condition category to which the type belongs is obtained according to the mapping table, and the mapping table also includes: The operating conditions cond_21, cond_22, cond_23 and cond_30 are classified in the C operating condition category. The operating condition type cond_40 is classified in the D type operating condition category.

4. The method for handling an accident of abnormal pressure in a small pressurized water reactor containment vessel according to claim 3, characterized in that: For Class B working conditions, the corresponding processing strategies also include: Continuously determine the working condition type of the abnormal pressure working condition to be analyzed and the working condition category to which the working condition type belongs, and when the working condition category to which it belongs is changed to the Class C working condition category, execute the processing strategy corresponding to the Class C working condition category; For Class C working conditions, the corresponding processing strategies include: Confirm containment isolation, Confirm that the passive containment cooling system is operating normally, Isolate the source of mass-energy release within the containment, Start the external spraying of containment. The operating condition type of the abnormal pressure condition to be analyzed and the operating condition category to which the operating condition type belongs are continuously determined. When the operating condition category to which it belongs is changed to Class B operating condition category, the external spraying of the containment is shut down and the processing strategy corresponding to Class B operating condition category is executed.

5. The method for handling an abnormal pressure accident of a small pressurized water reactor containment vessel according to claim 4, characterized in that: For Class C working conditions, the corresponding processing strategies also include: Continuously determine the working condition type of the abnormal pressure working condition to be analyzed and the working condition category to which the working condition type belongs, and when the working condition category to which it belongs is changed to the D-type working condition category, execute the processing strategy corresponding to the D-type working condition category; For Class D working conditions, the corresponding processing strategies include: Confirm containment isolation, Start the external spraying of containment. Continue to judge the operating condition type of the abnormal pressure condition to be analyzed and the operating condition category to which the operating condition type belongs. When the operating condition category to which it belongs is changed to Class C operating condition category, execute the processing strategy corresponding to Class C operating condition category. When the operating condition category to which it belongs is still Class D operating condition category, start internal spraying of the containment.

6. The method for handling an abnormal pressure accident of a small pressurized water reactor containment vessel according to claim 5, characterized in that: For Class C working conditions, the corresponding processing strategies also include: Monitor the temperature inside the containment. If the internal refueling water tank cannot be cooled by the normal waste heat removal system or equipment cooling water, the external shell spray system and the passive containment cooling system will be used as the long-term heat sink of the internal refueling water tank.

7. A system for implementing the method for handling an abnormal pressure accident of a small pressurized water reactor containment vessel according to any one of claims 1 to 6, characterized in that: include: The judgment module is used to judge the type of the abnormal pressure condition to be analyzed. The first acquisition module is connected to the judgment module and is used to obtain the operating condition category to which the operating condition type belongs. The second acquisition module is connected to the first acquisition module and is used to acquire the corresponding processing strategy according to the working condition category. An execution module is connected to the second acquisition module and is used to execute the processing strategy.

8. The system according to claim 7, characterized in that It also includes a storage module, in which a mapping relationship between each operating condition type and each operating condition category is stored, and a processing strategy corresponding to each operating condition category is also stored.

Images