KR102089081B1 - Method of analyzing multiple spurious operation for fire in nuclear power plant - Google Patents

Abstract

The present invention provides a method for analyzing multiple malfunctions, which analyzes the effects of multiple malfunctions due to a fire in a nuclear power plant. The method for analyzing multiple malfunctions comprises the steps of: preparing a database for storing information related to the nuclear power plant; preparing a plurality of accident scenarios related to the multiple malfunctions; generating a plurality of success path logic diagrams corresponding to the plurality of accident scenarios, respectively; using the database, extracting cables related to each of the plurality of accident scenarios and generating a plurality of related cable lists; using the database, selecting an analysis object fire zone to analyze the effect of the multiple malfunctions from among a plurality of fire zones in the nuclear power plant; using the database, extracting burnout cables passing through the analysis object fire zone to generate a burnout cable list; comparing the burnout cable list with the plurality of related cable lists, and extracting an accident scenario affected by the occurrence of a fire in the analysis object fire zone; and evaluating whether or not a success path corresponding to the extracted accident scenario is achieved by negatively considering the operating states of devices connected to the burned cables in the success path logic diagram corresponding to the extracted accident scenario.

Description

Method of analyzing multiple spurious operation for fire in nuclear power plant

The present invention relates to a method for analyzing a multiple malfunction in a nuclear power plant fire, and more specifically, to extract a cable to be taken to prevent an accident in which a safety stop function is lost due to a multiple malfunction due to a fire in a nuclear power plant. How to do.

Nuclear power plants are equipped with safety facilities against various accidents such as loss of power or loss of cooling water. For example, in the event of a loss of power, safety equipment is provided such that cooling water can be passively supplied using only gravity. In the event of an accident, equipment related to the safety shutdown of a nuclear power plant must be able to operate normally. In particular, even in the event of a fire, the reactor must be able to reach and remain in a safe state. Accordingly, an analysis is required to demonstrate that the reactor can reach and remain in a safe state even if some equipment is burned out due to a fire in a specific area.

In 1975, the need for a review of the impact of nuclear power plant safety on fires in power plants was raised, starting with the fire incident at Unit 1 of Browns Ferry in the United States. In the past, when evaluating the safety of a nuclear power plant, the impact of the system due to a single malfunction of the safety stop device was evaluated, but recently, it has been requested that the safety stop function of the nuclear power plant should not be lost even when multiple malfunctions of the safety stop device occur in combination of two or more. Is getting

The problem to be solved by the present invention is to provide a method for analyzing multiple malfunctions that analyzes the effects of multiple malfunctions due to a fire in a nuclear power plant.

Another problem to be solved by the present invention is to provide a method for analyzing a cable to be prepared for a fire in a nuclear power plant.

Another problem to be solved by the present invention is for a computing device to perform a multi-error analysis method for analyzing the effects of multiple malfunctions caused by a fire in a nuclear power plant or a cable analysis method in preparation for a fire in a nuclear power plant. It is to provide a computer program.

The method for analyzing multiple malfunctions according to an aspect of the present invention is to analyze the effects of multiple malfunctions caused by a fire in a nuclear power plant. The multiple malfunction analysis method includes preparing a database for storing information related to the nuclear power plant, preparing a plurality of accident scenarios related to the multiple malfunctions, and a plurality of success path logic diagrams respectively corresponding to the plurality of accident scenarios Generating, using the database, extracting cables associated with each of the plurality of accident scenarios and generating a plurality of related cable lists, using the database, among a plurality of fire zones in the nuclear power plant Selecting a fire zone to be analyzed to analyze the effects of the multiple malfunctions, using the database, extracting burnout cables passing through the fire zone to be analyzed to generate a burnout cable list, and the burnout cable list to the Multiple related cable necks Comparing with, extracting an accident scenario affected by the fire occurrence of the fire zone to be analyzed, and the operating state of the devices connected to the burnout cables in the success path logic diagram corresponding to the extracted accident scenario Considering negatively, evaluating whether a success path corresponding to the extracted accident scenario is achieved is evaluated.

According to another aspect of the present invention, an analysis method of a cable to be prepared for a fire in a nuclear power plant includes preparing a database including cable information about the cable of the nuclear power plant, preparing an accident scenario, and the accident scenario. Generating a success path logic diagram for, and extracting a cable related to the accident scenario from the database, and determining the cable to be taken to meet the success path logic diagram.

According to another aspect of the present invention, a computer program stored in a medium is provided to execute the above-described method using a computing device.

According to the multiple malfunction analysis method of the present invention, even if a multiple malfunction occurs due to a fire occurring in a nuclear power plant, if a success path that does not lose a safety stop function can be achieved, or if a success path cannot be achieved, a success path In order to achieve this, it is possible to extract the cable to be targeted. It is possible to prove that the nuclear reactor can reach and maintain the safety stop state even if a multi-malfunction occurs due to a fire in the nuclear power plant, thereby improving the stability and reliability of the nuclear power plant.

1 shows a multiple malfunction analysis system for performing a multiple malfunction analysis method according to an embodiment of the present invention.
2 shows an internal configuration of a computer according to an embodiment of the present invention.
3 exemplarily shows information stored in the database 200 according to an embodiment of the present invention.
4 exemplarily shows information stored in the memory 120 according to an embodiment of the present invention.
5 is a flowchart of a method for analyzing multiple malfunctions according to an embodiment of the present invention.
6 is a flowchart of a method for analyzing a cable to be taken according to another embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments presented below, but may be implemented in various different forms, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. do. The embodiments presented below are provided to make the disclosure of the present invention complete, and to fully disclose the scope of the invention to those skilled in the art to which the present invention pertains. In the description of the present invention, when it is determined that a detailed description of related known technologies may obscure the subject matter of the present invention, the detailed description will be omitted.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described in the specification, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components.

1 shows a multiple malfunction analysis system for performing a multiple malfunction analysis method according to an embodiment of the present invention.

Referring to FIG. 1, the multi-error analysis system 10 includes a computing device 100 and a database device 200.

The multiple malfunction analysis system 10 is a system for performing a multiple malfunction analysis method for analyzing the effects of multiple malfunctions due to a fire in a nuclear power plant according to an embodiment of the present invention.

In the past, when evaluating the safety of a nuclear power plant, the effect of the system due to a single malfunction of the safety stop device was evaluated, but the multiple malfunction analysis method according to the present invention is a safety stop capability of a nuclear power plant when multiple malfunctions of the safety stop device occur in combination of two or more. To evaluate. Evaluating a nuclear power plant's safety stop capability means evaluating whether or not a nuclear reactor can reach and maintain a safe state in the event of a fire.

As a result of the multiple malfunction analysis according to an embodiment of the present invention, when a nuclear power plant fails to secure a safety stop capability in the event of a fire, it is possible to extract or determine an action target cable that requires action to secure the safety stop capability. In this regard, the multi-malfunction analysis system 100 may perform a method of analyzing a cable to be prepared for a fire in a nuclear power plant according to another embodiment of the present invention.

The malfunction types of the electric circuit can be classified into three types, open-circuit, short-to-ground, and hot short. Here, the ground fault and the overheat short circuit have different influences on the circuit depending on the occurrence location.

Disconnection is defined as the state in which electrical continuity of the circuit is lost due to the loss of conductors due to fire. If a disconnection occurs in the electrical circuit, loss of control function of the target device, loss of power, or state change of the excited device may result.

Ground fault is defined as the state in which the cable insulation is destroyed by a fire so that the cable conductor comes into contact with the earth or a grounded electric line (tray, conduit, etc.). Ground faults result in loss of control or drive power to the safety stop device, and if there is no proper protection coordination in the target circuit, the operation of the breaker (breaker or fuse) of the upper power distribution system may affect more devices. have.

Ground faults in the control and power circuits can cause breakers to open, resulting in loss of control and power to safety stop devices. In addition, if the control power of the excited device is lost due to a ground fault, it may cause malfunction of other devices through a circuit interlocked with the power loss of the interlocked relay.

There are two types of ground faults: short-to-ground on grounded circuits and short-to-ground on grounded circuits.

Overheating short-circuit is defined as the cause of insulation damage to conductors in the same cable, conductors between cables, or to specific conductors, and this causes undesired voltage to be pressurized between the damaged conductors, which may result in the device being unavailable or malfunctioning. have.

Overheating short circuit between the pressurized conductor and the unpressurized conductor in the same cable may cause malfunction of the device, and may cause malfunction of other devices through interlocked circuits. In addition, overheating short circuit in the electric drive valve control circuit may bypass the torque switch and limit switch, which are mechanical protection equipment, and damage the motor of the electric drive valve.

There are two types of overheating short circuits: A hot short on grounded circuits and A hot short on ungrounded circuits. In addition, there are additional types of overheating short circuits, such as overheating short circuits that affect solenoid valves, overheating short circuits of three-phase AC power circuits, and overheating short circuits of DC power circuits.

The computing device 100 is connected to a database device 200 that stores information related to a nuclear power plant. Program code for executing a multi-error analysis method according to an embodiment of the present invention may be installed in the computing device 100. The computing device 100 generates a plurality of success path logic diagrams corresponding to a plurality of accident scenarios associated with multiple malfunctions, extracts cables associated with each of the plurality of accident scenarios, generates a plurality of related cable lists, and nuclear power Among the multiple fire zones in the power plant, the fire zone to be analyzed to analyze the effects of multiple malfunctions is selected, and the burned out cables passing through the fire zone to be analyzed are extracted to generate a burned out cable list, and the burned out cable list is connected to a plurality of cables. Compared to the list, the accident scenarios affected by the occurrence of fire in the fire zone to be analyzed are extracted, and the operational status of the devices connected to the burned cables is negatively considered in the success path logic diagram corresponding to the extracted accident scenarios. In order to evaluate whether the success path corresponding to the extracted accident scenario is achieved, There.

It is assumed that devices located in the fire zone to be analyzed and cables passing through the fire zone to be analyzed are burned out by the fire in the fire zone to be analyzed. When the success path corresponding to the extracted accident scenario is achieved, it can be determined that the safety stop capability is not lost even if a multiple malfunction occurs due to a fire occurring in the fire zone to be analyzed.

Program code for executing the cable analysis method to be measured according to another embodiment of the present invention may be installed in the computing device 100. in this case,

The database device 200 stores the cable information on the cable of the nuclear power plant, the computing device 100 prepares an accident scenario, generates a success path logic diagram for the accident scenario, and the accident scenario from the database device 200 It is possible to extract the cables related to and determine the cable to be taken to meet the success path logic.

The computing device 100 may be a personal computer (PC), a notebook PC, a tablet PC, a smart phone, or other mobile computing devices, but is not limited thereto. In the following, the computing device 100 is referred to as a computer 100 for easy understanding.

The computer 100 may access the database device 200 to store data or read data stored in the database device 200. The database device 200 may store fire compartment information, device information, laying path information, and cable information in relation to a nuclear power plant. The cable information may include routing information, connector information, cable channel information, and cable type information.

The database device 200 may be a DB server storing a database, and the computer 100 may be connected to the database device 200 through a network. In this case, a plurality of computers 100 may access the database device 200 and execute analysis methods according to various embodiments of the present invention. According to another example, the database device 200 may be a storage device mounted or installed in the computer 100. Hereinafter, the database device 200 is referred to as a database 200 by focusing on a set of data stored in the database device 200 that is stored rather than the hardware form of the database device 200.

The information stored in the database 200 will be described in more detail below with reference to FIG. 3.

2 shows the internal configuration of the computer 100 according to an embodiment of the present invention.

Referring to FIG. 2, the computer 100 may include a processor 110, a memory 120, a communication module 130 and an input / output device 140.

The processor 110 may perform basic arithmetic, logic, and input / output operations, and execute, for example, program code stored in the memory 120.

The memory 120 is a recording medium that the processor 110 of the computer 100 can read, and a non-permanent mass storage device such as random access memory (RAM), read only memory (ROM), and a disk drive. device). The operating system and at least one program or application code may be stored in the memory 120. Program code capable of executing the analysis method according to various embodiments of the present invention may be stored in the memory 120.

In the memory 120, information necessary for the computer 100 to execute the analysis method according to various embodiments of the present invention or information generated in the process of executing the information may be stored. According to an example, the memory 120 includes an accident scenario, a success path and a success path logic diagram corresponding to each of the accident scenarios, a list of related cables and related devices, and a list of related devices, and a fire in the fire zone corresponding to each of the accident scenarios. A list of burnout cables burned by and a list of burnout devices may be stored.

The communication module 130 may connect to a network to receive data or transmit data. The communication module 130 allows the computer 100 to access a public or private network such as the Internet. According to an example, the computer 100 may access the database 200 through the communication module 130.

The computer 100 may store data in the database 200 and read data stored in the database 200. For example, the computer 100 may input information related to a nuclear power plant into the database 200 or modify or delete data stored in the database 200. The computer 100 may search for and receive desired data from the database 200 by sending a query to the database 200.

The input / output device 140 may receive input from the user, transmit it to the processor 110, and output information received from the processor 110 to the user. For example, the input device of the input / output device 140 may include a keyboard, mouse, and touch screen. The output device may include a video display device such as a monitor or display, and a voice output device such as a speaker or earphone.

3 exemplarily shows information stored in the database 200 according to an embodiment of the present invention.

Referring to FIG. 3, the fire zone information 210, device information 220, laying path information 230, and cable information 240 may be stored in the database 200.

The fire zone information 210 is information on fire zones that are a basic unit of multi-malfunction analysis according to the present invention. Nuclear power plants may have several buildings. Each of the buildings is divided into fire zones, each of the fire zones is divided into fire zones, and each of the fire zones may consist of at least one compartment. The fire zone information 210 may include information about a building, fire zone, fire zone, or compartment that constitutes a nuclear power plant. In the present specification, the fire zone may correspond to a fire zone, fire zone, or compartment.

According to an example, since the inside of the power plant is divided into compartments, and a firewall is isolated between the compartments and the compartments, a fire zone can be classified for each compartment. In this case, the fire zone information 210 may include information on the building to which the compartment belongs, the altitude, the size and area of the compartment, and the adjacent compartment.

According to another example, since the fire scale is different according to the degree of the combustible material in the compartment for each fire zone, the amount of heat generated by calculating the degree of the combustible material in the fire zone may be stored in the fire zone information 210. The heat dissipation in the fire zone can be used to assess the degree of damage to the cables in each fire zone.

The fire zone information 210 may include building information about buildings in a nuclear power plant. The building information may include the building's unique number, the building's Korean and English name, and a description of the building.

The fire zone information 210 may include fire zone information about the fire zone in the building. The fire prevention area information may include a building identification number of a building to which the fire protection zone belongs, and a fire area ID of the fire protection zone. The fire zone information may further include a description of the fire zone.

The fire zone information 210 may include fire zone information about fire zones in the fire zone. The fire protection zone may include at least one compartment. It has a hierarchical structure divided into fire zones, fire zones, and compartments. That is, every fire zone is divided into at least one fire zone, and the fire zone is divided into at least one compartment.

The fire zone information includes the fire zone identification number of the fire zone to which the fire zone belongs, the fire zone ID of the fire zone, the building's unique number of the fire zone, and / or the fire zone. It may include a description.

The fire zone information 210 may include compartment information about compartments in the fire zone. The compartment is the basic unit of the fire zone, and all appliances, cables, combustible materials, ignition sources, and fire protection facilities are all located within the compartment. Compartment information includes the unique number of the fire zone in the fire zone to which the compartment belongs, the unique number of the compartment in the compartment, the unique number of the building in the building to which the compartment belongs, the unique information of the fire zone in the fire zone to which the compartment belongs, and a description of the compartment, It may include information such as the floor area of the compartment.

The device information 220 is information of devices for analyzing multiple malfunctions.

The device information 220 may include fire zone information to which the device belongs, in order to be extracted as a related device and a burned device during analysis of multiple malfunctions. According to an example, the device information 220 may include location information in the compartment so that it can know what type the device is installed in. According to another example, the device information 220 may include the arrangement direction of the device, the width of the installation surface, and size information in order to evaluate the degree of damage to the device when a fire occurs in the compartment.

The device information 220 may include a system number of the corresponding device. Through the system number of the device information 200, it can be easily analyzed which function the device performs and which system it belongs to.

The device information 220 may include power and control channel information connected to the corresponding device. The power source and control channel information of the device information 200 may be used to determine whether the device is multiplicative and the effect of the device upon detailed analysis of the cable.

The device information 220 may include non-power state information regarding an operation state when power supply to the corresponding device is cut off. For example, if the device is a valve, if the power supply is closed when the power supply is cut off, "Fail Close" is stored as non-power status information, and if open, "Fail Open" Can be saved. The non-power state information of the device information 220 may be used for detailed analysis according to a cable malfunction type.

All devices in a power plant can be identified by their device number. The device information 220 may include a device identification number of the device, a power classification of the device, a location of the device, a safety stop related to the device, and a safety stop function related to the device.

The power classification of the corresponding device may be information on a power source and a power line supplying power to the corresponding device. The location of the device can be stored as the unique number of the compartment where the device is located.

Devices may be divided into devices related to the safety stop function and devices not related to the safety stop function. Devices related to the safety stop function are referred to as safety stop devices, and devices not related to the safety stop function are referred to as non-safe stop devices.

Since the safety stop function must be performed even in a situation where a part of the nuclear power plant fails, the safety stop function is multiplexed to increase its reliability. Using the device information 200, an alternative safety stop device performing the same function as a specific safety stop device may be searched.

Cables of nuclear power plants are prone to burnout in the event of a fire, and devices connected to the burnt out cables may malfunction. As the cable is burnt out, the disconnection is disconnected, the insulation between the pair of cables is broken, the short circuit where the pair of cables are connected to each other, and the outer sheath of the cable is broken to connect with another conductor, especially a conductor that is connected to ground. There may be a ground fault. All cables can be identified by cable number.

The laying path information 230 is information about a tray and a conduit through which cables are laid. The cables connect the devices through trays or conduits installed along the laying path. The laying path information 230 may include information such as a building where a tray and a conduit are installed, a fire zone, an installation height, a location, and a size.

Some of the conduits can be fire-wrapped for separation between different channels. Since the fire-wrapped conduit has a difference in the effect of fire compared to other cables, the laying route information 230 may include information about the presence or absence of fire-lapping.

The cable is laid on several trays and several conduits connected in series. By storing which trays and which conduits cables are laid out, it is possible to extract a list of burned cables burned by fire for each fire zone.

The cable information 240 may include routing information of a corresponding cable, connection device information, cable channel information, and cable type information. According to an example, the cable information 240 includes a cable identification number of the cable, a cable type of the cable, information of a device connected to the cable, and a fire zone where the cable is located, and a tray or conduit where the cable is laid. Information.

The routing information is information for knowing which path a specific cable connects to devices. When the laying route information 230 and the cable information 240 are cross-referenced, the cable number may be extracted for each laying route.

The connected device information is information of devices connected to the corresponding cable. The connected device information can be stored by dividing the devices connected to the corresponding cable into 'From devices' and 'To devices'. The connector information can be used to extract related cables related to the accident scenario.

The cable channel information is information about a channel classified for each cable. The manufacturer is different depending on whether the cable is safe or unsafe, and the characteristics of the cable are also different. Through the cable channel information, the separation requirements and multiplicity of the cable can be confirmed.

Cables can be classified into power and measurement / control cables depending on the purpose, and the cable type information is information about the type of the cable. The type of cable can be stored using the service code. It can be used to classify malfunction types in detailed cable analysis.

Cables in nuclear power plants range from thousands to tens of thousands, and connect countless devices to each other. When the cable information 240 and the laying path information 230 were not stored in the database 200, it was almost impossible to inspect all cables passing through one fire zone. This is because the number of cables passing through a fire zone is not only quite large, but also these cables pass through various spaces and connect devices with various spaces to each other. Therefore, assuming that a fire occurs in a fire zone, devices that will be burned by the fire can be extracted, but cables that will be burned by the fire or connected to these cables will become inoperable or unexpectedly malfunction. It was almost impossible to extract all possible devices.

However, by storing both the cable information 240 and the laying path information 230 in the database 200, it is possible to perform a multi-error analysis method according to the present invention.

In addition, in order for the computer 100 to perform the multi-error analysis method according to the present invention, data related to a fire in a nuclear power plant may be stored in a storage medium as a database 200.

The database 200 may further store combustible material type information and combustible material information. The type of combustible material may include the name of the combustible material, the description of the combustible material, the heat content per unit mass or volume of the combustible material, the unit of the heat content, and the properties of the combustible material. have.

The combustible material information is information for calculating the total amount of heat generated by each fire zone, the element (Component, for example, a device or cable) containing the combustible material, the description of the element, the location on the protective area of the element, the combustible material It may include information such as the type and quantity, and the type of the combustible material (eg, fixed / temporary). For each element, the total heat value can be calculated by multiplying the heat content and quantity for each combustible material. In this way, the total calorific value can be calculated by summing up each fire zone and each fire zone.

The database 200 may further store ignition source type information and ignition source information. The ignition source type information may include information such as an ignition source type, a description of the ignition source type, and reference materials for material properties. The ignition source information is stored for each fire zone or fire zone, and may include a tag number (Tag No.) for each ignition source, a type (fixed / temporary) of the ignition source, and a location on the protection zone of the ignition source.

The database 200 may further store fire protection equipment information. Fire protection equipment includes detection equipment, induction and emergency lighting, fire extinguishing systems, drainage / curbstones, fire hydrants, portable fire extinguishers, air conditioning and ventilation systems, evacuation and access routes.

4 exemplarily shows information stored in the memory 120 according to an embodiment of the present invention.

Referring to FIG. 4, information required for executing a multi-error analysis method according to an embodiment or information generated in a process of executing the method may be stored in the memory 120. According to an example, the memory 120 includes an accident scenario 121, a success path 122, a success path logic diagram 123, a related cable list 124, a related device list 125, and a burnout cable list 126. And the burnout device list 127 may be stored.

The memory 120 stores a plurality of accident scenarios 121 that may cause loss of the safety stop function. The accident scenarios 121 may be constructed based on data from the US industry (NEI 00-01, Revision No. 3). The safety stop function means a function for taking measures to ensure that the nuclear reactor reaches a safety stop state and maintains the safety stop state due to a fire in a nuclear power plant.

According to the accident scenario 121, it is assumed that the power plant is in a full power state, and the rest of the systems other than those specified in the scenario perform a unique function unless otherwise specified.

The accident scenario 121 includes scenarios related to volume control and soundness of the reactor coolant system, scenarios related to removing residual heat of the reactor coolant system, scenarios related to pressure control of the reactor coolant system, and scenarios related to control of the reactivity of the reactor coolant system. Scenarios, and scenarios related to the loss of sub-system functionality in nuclear power plants.

Reactor coolant system volume control is a function necessary to achieve and maintain a high temperature stop, and when the soundness of the pressure boundary is lost, the coolant leaks and an accident such as a loss of coolant occurs, resulting in loss of volume control function as well as achieving and maintaining a safety stop after a fire. Can have a negative impact on

For example, one of the scenarios related to the volume control and soundness of the reactor coolant system is a scenario where all reactor coolant pump sealing cooling functions are lost.

Another exemplary one is a charge pump unavailable scenario. This scenario may occur when the valves at the rear end of the volume control tank (VCT) are locked due to a malfunction, and the flow path from the boric acid storage tank (BAST) is not secured due to the malfunction. Therefore, the safety stop function may not be lost if at least one of the above two flow paths is secured. In this regard, the success path of this scenario may be a flow path from a volume control tank (VCT) to a filling pump, or a flow path from a boric acid storage tank (BAST) to a filling pump.

Residual heat removal of the reactor coolant system is to remove residual heat generated from the reactor coolant system to achieve a high temperature stop. In general, the reactor coolant system is naturally circulated or forced circulated, and at the same time, steam is discharged to the secondary exhaust valve of the steam generator to remove residual heat. Residual heat removal function to achieve low temperature stoppage must also be maintained, so operation restriction or loss of function should not occur due to other systems of residual heat removal system.

One of the scenarios related to the removal of residual heat from the reactor coolant system is a steam generator take-off scenario, which is caused by a malfunction of the steam generator opening (closing failure). This scenario does not occur if the flow path of the steam generator withdrawal system is secured. The success path may be a steam generator take-off system flow path.

For the pressure control of the reactor coolant system, the pressurizer heater, the pressure release valve, and the steam discharge valve are used, and the pressure control function can be performed using the filling system while the volume control and the pressurizer are isolated.

Reactivity control of the reactor coolant system is to safely stop the reactor and ensure a safety stop margin to maintain a low temperature stop. In general, the temperature of the reactor coolant is controlled and the reactivity is controlled by filling and adding boric acid water using a supplementary system.

Auxiliary systems include power systems, cooling systems and air purification systems. The power system performs a function of supplying power to the safety system, and power power is supplied through a power facility connected to a 4.16 kV safety class bus, and DC and AC power for control is supplied through a control panel. The cooling system mainly supplies axial sealing of safety-related heat exchangers and safety-related pumps, and equipment cooling water to diesel generator cooling systems. The air conditioning system performs a function of maintaining the temperature of the building or the compartment within the operating temperature range of the safety-related equipment, and mainly maintains cooling of the main control room, the diesel generator and control room, the switchboard room, and the compartment where the safety-related equipment is installed.

A plurality of success paths 122 corresponding to a plurality of accident scenarios may be stored in the memory 120.

The success path 122 means a path that makes the conditions of occurrence of the corresponding accident scenarios unfulfilled. In relation to the safety stop function, the success path 122 may be mainly in the form of a flow path.

The success path 122 may include detailed success paths that are independent of each other. For example, if the occurrence condition of the accident scenario includes a logical relationship between the first condition and the second condition, and the first and second conditions, the success path 122 is the first condition that causes the first condition to be unfulfilled. It may include a detailed success path, a second detailed success path that makes the second condition unfulfilled, and a logical relationship between the first and second detailed success paths.

If the logical relationship can prevent the occurrence of the corresponding accident scenario when one of the independent first and second detailed success paths is achieved, the logical relationship between the first and second detailed success paths is an 'OR' relationship , If both the first and second detailed success paths must be achieved to prevent the occurrence of the corresponding accident scenario, the logical relationship between the first and second detailed success paths is an 'AND' relationship.

The memory 120 may store a plurality of related device lists 125 each associated with a plurality of accident scenarios 121. According to an example, the related device list 125 is a list of devices related to the corresponding accident scenario 121.

The plurality of related device lists 125 may be respectively associated with the plurality of success paths 122. According to an example, the related device list 125 may be a list of devices related to the corresponding success path 122, that is, devices constituting the success path 122. For example, when the success path 122 is a flow path from the volume control tank (VCT) to the filling pump, the valves and pumps disposed between the volume control tank (VCT) and the filling pump correspond to the success path 122 It may be related devices.

A plurality of success path logic diagrams 123 corresponding to the plurality of accident scenarios 121 may be stored in the memory 120. The success path logic diagram 123 may include an operation state of related devices and a logical relationship between the related devices to achieve the success path 122 of the corresponding accident scenario 121.

For example, it is assumed that the first success path logic diagram 123 corresponds to the first accident scenario 121. The first accident scenario 121 is assumed to occur when both the first condition and the second condition are fulfilled. In order to prevent the occurrence of the first accident scenario 121, the first accident scenario may be achieved even if only one of the first detailed success path for the unfulfillment of the first condition and the second detailed success path for the unfulfillment of the second condition is achieved. 121) can be prevented. In this case, the success path may be expressed as "first detailed success path OR first detailed success path".

Assuming that devices A, B, and C exist in the first detailed success path, and the first detailed success path is achieved when the device A is closed and one of the devices B and C is open I assume. Assuming that closed is 1 and open is 0 as a Boolean logical type, the logic diagram of the first detailed success path may be expressed as a Boolean logical type such as "A AND (B 'OR C')".

Assuming that devices D, E, F, and G exist in the second detailed success path, and the second detailed success when device E starts or device E stops and one of devices F and G is closed Assume that the path is achieved. Assuming that the start is 1 and the stop is 0 as a Boolean logical type, the logic diagram of the second detailed success path may be expressed as a Boolean logical type such as "(D OR E ') AND (F OR G)".

In this case, the first success path logic diagram 123 may be expressed as a Boolean logical type such as "{A AND (B 'OR C')} OR {(D OR E ') AND (F OR G)}". have.

According to another example, the first success path logic diagram 123 may be expressed in the form of 'device number-state'. For example, in the example above, the first success path logic diagram 123 is "{A-closed AND (B-opened OR C-opened)} OR {(D-started OR E-stopped) AND (F-closed OR G-closed)} ".

A plurality of related cable lists 124 respectively corresponding to the plurality of accident scenarios 121 may be stored in the memory 120. The related cable list 124 may be a list of cables related to the corresponding accident scenario 121. The related cable list 124 may be a list of cables connected to related devices related to the corresponding accident scenario 121.

The related cable list 124 may include a power cable supplying power to the related device, and a control cable transmitting control signals for controlling the related device. According to some embodiments, the associated cable list 124 may further include a metrology cable carrying a metrology signal indicative of the state or measurement of the associated instrument.

The memory 120 may store a burnout cable list 126 in which burnout cables related to the fire zone to be analyzed are recorded. The fire zone to be analyzed is a fire zone to perform a multiple malfunction analysis according to an embodiment of the present invention among fire zones stored in the fire zone information 210 of the database 200.

Burned cables may be extracted as cables passing through the fire zone to be analyzed using the cable information 240 and the laying path information 230 of the database 200.

The memory 120 may store a burnout device list 127 in which burnout devices related to the fire zone to be analyzed are recorded. The burned out devices may include devices located in the fire zone to be analyzed and devices that are not connected to burnout cables passing through the fire zone to be analyzed and possibly fail to perform normal operation.

5 is a flowchart of a method for analyzing multiple malfunctions according to an embodiment of the present invention.

The method for analyzing multiple malfunctions of the present invention is to analyze whether a safety stop function can normally operate even if a multiple malfunction of an electric circuit is caused by a fire in a fire zone in a nuclear power plant. Assuming that a fire occurs in each of the fire zones in the nuclear power plant, multiple malfunctions are analyzed.

According to the multiple malfunction analysis method of the present invention, it is assumed that only one initial fire occurs primarily in one of the fire zones in the nuclear power plant. It is assumed that the first fire does not propagate from the fire zone where the first fire occurred to other adjacent fire zones if appropriate fire protection equipment (eg fire barriers, fire suppression and detection equipment) is in place.

If there are several exhalation units in a nuclear power plant, it is assumed that two or more power plants do not fire simultaneously. However, it is assumed that fires in public facilities affect two or more power plants at the same time.

It is assumed that the alienated power is lost at the same time as the fire or within 72 hours of the fire. It is assumed that other design-based accidents, except for a power loss accident, do not occur at the same time as the fire, except as a result of the fire. We do not assume the worst fires that occur at the same time as accidents that are not related to fires in safety-related systems, such as other power plant accidents or serious natural disasters (tornadoes, floods, earthquakes, etc.).

In the event of a fire, all unprotected equipment and cables in the fire zone where the fire occurred are damaged and are considered to be inoperative. That is, in the present invention, the fire is assumed to be a design reference fire. Design-based fire means a design-based virtualization material that considers that all combustible materials in a specific fire zone are completely burned for the most conservative design. Therefore, it is assumed that all devices and cables in the fire zone are damaged by the fire. However, it is considered that equipment and cables are protected with fire-resistant barriers or fire-retardant materials, or equipment filled with water, such as piping and heat exchangers, is not damaged.

According to another embodiment, when the calorific value can be calculated according to the amount of combustible materials in the fire zone, the damage degree of each cable can be predicted according to the total heat generation amount and the characteristics of the cables in the fire zone. In this case, it can be assumed that even a cable in a fire zone is damaged by the predicted degree of damage. In addition, when the cable or the conduit on which the cable is laid is wrapped with a fire retardant material, it can be assumed that the cable is not damaged.

It is assumed that all damageable appliances and cables in the fire zone are more likely to be unfavorable or malfunctioning. According to an example, it is assumed that the burned out equipment in the fire zone is in a state that has a negative result in the logic of the success path.

For example, if the pump in the fire zone is stopped and the success path is achieved in the success path logic, it is assumed that the pump malfunctions and starts by fire.

Hereinafter, a method for analyzing multiple malfunctions, which analyzes the effects of multiple malfunctions due to fire in a nuclear power plant, will be described in detail.

Referring to FIG. 5, a database 200 for storing information related to a nuclear power plant is prepared as illustrated in FIG. 3 (S10). The database 200 stores fire zone information 210, device information 220, laying path information 230, and cable information 240.

A plurality of accident scenarios 121 related to multiple malfunctions are prepared (S20). The plurality of accident scenarios 121 may be stored in the memory 120. The accident scenario 121 is a scenario that may cause a loss of the safety stop function, a scenario related to volume control and soundness of the reactor coolant system, a scenario related to removing residual heat of the reactor coolant system, and pressure control of the reactor coolant system It may include a scenario related to, a scenario related to the control of the reaction rate of the reactor coolant system, and a scenario related to the loss of the auxiliary system function of the nuclear power plant.

A plurality of success path logic diagrams 123 respectively corresponding to the plurality of accident scenarios 121 are generated (S30). The plurality of success path logic diagrams 123 may be stored in the memory 120. In order to generate a plurality of success path logic diagrams 123, a plurality of success paths 122 corresponding to a plurality of accident scenarios 121 may be generated, and the plurality of success paths 122 may also be memory 120 Can be stored in.

A method of generating the first success path logic diagram 123 in response to the first accident scenario 121 which is any one of the plurality of accident scenarios 121 will be described.

According to an embodiment, an occurrence condition for generating the first accident scenario 121 may be given. Based on the occurrence conditions of the first accident scenario 121, a first success path 122 may be generated that makes the occurrence conditions of the first accident scenario 121 unfulfilled. Related devices related to the first success path 122 may be extracted using the database 200. Related devices extracted in relation to the first success path 122 may be recorded in the first related device list 125 and stored in the memory 120. The operating state of the related devices and the logical relationship of the related devices to achieve the first success path 122 may be determined. A first success path logic diagram 123 that can prevent the occurrence of the first accident scenario 121 may be configured based on the operation state and logic relationship of related devices.

According to another embodiment, a plurality of occurrence conditions for generating the first accident scenario 121 may be given. In this case, the occurrence conditions of the first accident scenario 121 may be classified, and a logical relationship between the occurrence conditions may be established.

For example, when the first to third occurrence conditions are given in relation to the first accident scenario 121, and the first occurrence condition is achieved or both the second and third occurrence conditions are achieved, the first accident scenario ( Assuming that 121) occurs, the logical relationship between the first to third occurrence conditions may be the same as 'first occurrence condition OR (second occurrence condition AND third occurrence condition)'.

Detailed success paths may be generated to make each occurrence condition of the first accident scenario 121 unfulfilled. First to third detailed success paths may be generated that disagree with each of the first to third occurrence conditions. In the above example, the logical relationship between the first to third detailed success paths to prevent the occurrence of the first accident scenario 121 is' the first detailed success path AND (the second detailed success path OR the third detailed success path) ) '. That is, the first detailed success path must be achieved, and the first occurrence condition must be met, and the second or third detailed success path must be achieved, and either of the second and third occurrence conditions must be met, the first accident. The occurrence of the scenario 121 can be prevented.

The database 200 may be used to extract related devices related to each detailed success path. In the above example, first related devices related to the first detailed success path, second related devices related to the second detailed success path, and third related devices related to the third detailed success path may be extracted. have.

An operational state of related devices and a logical relationship of related devices to achieve respective detailed success paths may be determined. The first success path logic diagram 123 that can prevent the occurrence of the first accident scenario 121 based on the logical relationship between the occurrence conditions of the first accident scenario 121 and the operation state and logical relationship of related devices Can be configured.

By extracting cables associated with each of the plurality of accident scenarios 121 using the database 200, a plurality of related cable lists 124 corresponding to each of the plurality of accident scenarios 121 may be generated.

A first related cable list 124 may be generated in response to the first accident scenario 121 (S40). The cables of the first related cable list 124 may be cables connected to devices of the first related device list 125 generated in response to the first accident scenario 121.

Using the database 200, one fire zone that assumes that a fire has occurred is selected from among a plurality of fire zones in the nuclear power plant (S50). Since the effect of multiple malfunctions needs to be analyzed for one fire zone selected in step S50, it is referred to as a fire zone to be analyzed. According to an example, it can be assumed that both devices located in the fire zone to be analyzed and cables passing through the fire zone to be analyzed are burned out by the fire.

A burnout cable list 126 is generated by extracting burnout cables passing through the fire zone to be analyzed using the database 200 (S60). Cable information 240 and laying path information 230 stored in the database 200 may be used.

According to another example, a burnout device list 127 is generated by extracting burnout devices located in a fire zone to be analyzed using the database 200. According to another example, the burned-out device list 127 may include devices that are not likely to be located in the fire zone to be analyzed, but may be malfunctioned by cables in the burned-out cable list 126.

By comparing the burned-out cable list 126 with a plurality of related cable lists 124, an accident scenario 121 affected by a fire in the fire zone to be analyzed may be extracted (S70). When the burned out cable included in the burned out cable list 126 is included in the related cable list 124, an accident scenario 121 corresponding to the related cable list 124 may be extracted. It is assumed that the accident scenario 121 extracted in step S70 is the second accident scenario 121. In step S70, a plurality of accident scenarios 121 may be extracted.

According to another example, by comparing the burned device list 127 with a plurality of related device lists 125, an accident scenario 121 affected by a fire in the fire zone to be analyzed may be extracted. When the burned device included in the burned device list 127 is included in the related device list 125, an accident scenario 121 corresponding to the related device list 125 may be extracted.

The second success path logic diagram 123 corresponding to the second accident scenario 121 may be read from the memory 120. In the second success path logic diagram, it is possible to evaluate whether the second success path 122 corresponding to the second accident scenario 121 is achieved by negatively assuming the operation state of devices connected to the burnout cables ( S80).

According to another example, it is possible to negatively determine the operating state of the devices in the burned device list, and whether the second success path 122 corresponding to the second accident scenario is achieved may be evaluated.

In general, safety stop devices are redundant in order not to lose the safety stop function. Accordingly, even if the operating state of the devices connected to the burnout cables is negatively assumed, the success path can be achieved by the replacement devices operating normally by the redundancy design.

However, if the redundancy design is not perfect, it may happen that all the redundancy designed devices are lost due to a fire in a fire zone, and in this case, safety stop may not be possible. According to the multiple malfunction analysis method of the present invention, whether a safety stop function can be lost by a fire in a fire zone can be accurately analyzed.

If it is determined in step S80 that the second success path 122 is achieved without being affected by multiple malfunctions of the electric circuit even if a fire occurs in the fire zone to be analyzed, the process proceeds to step S50 to analyze other fire zones. It is possible to select the target fire zone, and perform steps S60 to S80.

If the second success path 122 is not achieved in step S80, the second success path 122 among the burned cables in the burnout cable list 126 is achieved based on the second success path logic diagram 123 A cable that is connected to a device that has been disabled can be determined as a target cable.

Once the target cable is determined, the target cable is protected with a protective material, the path of the target cable is changed, the positions of the devices connected to the target cable are moved, or the devices connected to the target cable are further multiplexed. By doing so, it can be ensured that the safety stop function is not lost.

6 is a flowchart of a method for analyzing a cable to be taken according to another embodiment of the present invention.

Hereinafter, a method of analyzing a target cable for preparing a fire in a nuclear power plant according to another embodiment of the present invention will be described.

Referring to FIG. 6, a database 200 including cable information regarding a cable of a nuclear power plant is prepared (S110). An accident scenario 121 is prepared that may cause the loss of the safety stop function of a nuclear power plant (S120). The success route logic diagram 123 for the accident scenario 121 is generated (S130). The cable related to the accident scenario 121 is extracted from the database 200 (S140). The cable to be taken which is a problem to satisfy the success path logic diagram 123 is determined (S150).

In step S130, based on the occurrence conditions of the accident scenario 121, a success path 122 may be generated to make the occurrence conditions of the accident scenario 121 unfulfilled. Related devices related to the success path 122 may be extracted from the database 200. The success path logic diagram 123 may be generated based on the generated success path 122 and the operation state of the extracted devices.

In step S150, cables connected to related devices related to the success path 122 are extracted from the database 200. Burned cables from the fire in the fire zone to be analyzed are extracted from the database 200. By comparing the burnout cables with cables connected to related devices, a cable to be taken can be derived that prevents the success path logic diagram 123 from being achieved.

In the above, the present invention has been described by specific matters such as specific components, etc. and limited examples and drawings, which are provided to help the overall understanding of the present invention, but the present invention is not limited to the above embodiments, and Those skilled in the art to which the invention pertains may seek various modifications and changes from these descriptions.

Accordingly, the spirit of the present invention is not limited to the above-described embodiments, and should not be determined, and all ranges equivalent to or equivalent to the claims, as well as the claims described later, are the scope of the spirit of the present invention. Would belong to

100: computing device
110: processor
120: memory
121: accident scenario
122: Success path
123: Success path logic diagram
124: Related cable list
125: Related device list
126: burnout cable list
127: list of burnout devices
130: communication module
140: input / output device
200: database device
210: fire zone information
220: device information
230: laying route information
240: cable information

Claims (16)

In the multi-function analysis method for analyzing the effects of multiple malfunctions due to fire in a nuclear power plant,
Preparing a database for storing information related to the nuclear power plant;
Preparing a plurality of accident scenarios related to the multiple malfunctions;
Generating a plurality of success path logic diagrams respectively corresponding to the plurality of accident scenarios;
Extracting cables related to each of the plurality of accident scenarios and generating a plurality of related cable lists using the database;
Using the database, selecting a fire zone to be analyzed from among a plurality of fire zones in the nuclear power plant to analyze the effect of the multiple malfunction;
Generating a burnout cable list by extracting burnout cables passing through the fire zone to be analyzed using the database;
Comparing the burned cable list with the plurality of related cable lists and extracting an accident scenario affected by a fire in the fire zone to be analyzed; And
And evaluating whether a success path corresponding to the extracted accident scenario is achieved by negatively considering an operating state of devices connected to the burned cables in the success path logic diagram corresponding to the extracted accident scenario, and ,
Generating the plurality of success path logic diagrams includes generating a first success path logic diagram corresponding to the first accident scenario,
Generating the first success path logic diagram,
Generating a first success path that renders the conditions of occurrence of the first accident scenario unfulfilled;
Extracting related devices related to the first success path;
Determining an operational state of the related devices and a logical relationship between the related devices to achieve the first success path; And
And constructing the first success path logic diagram that prevents the occurrence of the first accident scenario based on an operation state and a logic relationship of the related devices. According to claim 1,
Each of the plurality of accident scenarios is a scenario that causes a loss of a safety stop function to measure a nuclear reactor to reach a safety stop state and maintain a safety stop state due to a fire in the nuclear power plant. . According to claim 1,
The plurality of accident scenarios include a scenario related to volume control and soundness of the reactor coolant system, a scenario related to removing residual heat of the reactor coolant system, a scenario related to pressure control of the reactor coolant system, and a reaction control of the reactor coolant system. And a scenario related to the loss of the auxiliary system function of the nuclear power plant. According to claim 1,
The database includes fire zone information, device information, laying path information, and cable information. delete In the multi-function analysis method for analyzing the effects of multiple malfunctions due to fire in a nuclear power plant,
Preparing a database for storing information related to the nuclear power plant;
Preparing a plurality of accident scenarios related to the multiple malfunctions;
Generating a plurality of success path logic diagrams respectively corresponding to the plurality of accident scenarios;
Extracting cables related to each of the plurality of accident scenarios and generating a plurality of related cable lists using the database;
Using the database, selecting a fire zone to be analyzed from among a plurality of fire zones in the nuclear power plant to analyze the effect of the multiple malfunction;
Generating a burnout cable list by extracting burnout cables passing through the fire zone to be analyzed using the database;
Comparing the burned cable list with the plurality of related cable lists and extracting an accident scenario affected by a fire in the fire zone to be analyzed; And
And evaluating whether a success path corresponding to the extracted accident scenario is achieved by negatively considering an operating state of devices connected to the burned cables in the success path logic diagram corresponding to the extracted accident scenario, and ,
Generating the plurality of success path logic diagrams includes generating a first success path logic diagram corresponding to the first accident scenario,
Generating the first success path logic diagram,
Classifying the occurrence conditions of the first accident scenario and establishing a logical relationship between the occurrence conditions;
Generating detailed success paths that respectively disagree with the occurrence conditions;
Extracting related devices related to the detailed success paths, and determining an operational state of the related devices and a logical relationship between the related devices to achieve the detailed success paths; And
And constructing the first success path logic diagram to prevent the first accident scenario based on the logic relation between the occurrence conditions and the operation status and logic relation of the related devices. Method of analysis. According to claim 1,
Extracting devices related to each of the plurality of accident scenarios and generating a plurality of related device lists using the database; And
And generating a list of burnout devices by extracting devices located in the fire zone to be analyzed. The method of claim 7,
The step of extracting the accident scenario includes comparing the burned device list with the plurality of related device lists. The method of claim 8,
The step of evaluating whether or not the success path is achieved includes negatively determining an operation state of devices in the burned device list in a success route logic diagram corresponding to the extracted accident scenario. . According to claim 1,
If a success path corresponding to the extracted accident scenario is not achieved, a cable connected to a device that prevents the success path from being achieved among the burned cables based on a logic diagram of the success path corresponding to the extracted accident scenario The method further comprising the step of determining the cable to be corrected. According to claim 1,
Generating the burned cable list for the remaining fire zones among the plurality of fire zones, extracting the accident scenario, and evaluating whether or not a success path corresponding to the extracted accident scenario is achieved Multiple malfunction analysis method, characterized in that. delete delete delete delete A computer program stored in a medium for executing the method of any one of claims 1 to 4 and 6 to 11 using a computing device.

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