JPS5934193A - Emergency operation guide device of atomic power plant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for operating a nuclear power plant that provides an operating method for guiding the nuclear power plant to a target state while ensuring safety when an abnormal situation occurs in the nuclear power plant. The present invention relates to an abnormal driving guide device.

Conventionally, for example, in an emergency operation guide device for a boiling water nuclear power plant (hereinafter referred to as a BWR plant), the contents of an emergency operation procedure manual are stored in a computer. Based on this, the system guides operators on how to operate in abnormal situations. However, the emergency operating procedure manual is originally designed to handle 1. For reference in selecting an operating method, an operating method for one typical abnormality development situation is prepared as an example for each typical initiating event. Therefore, conventional devices that store an emergency operating procedure manual in a computer and guide operating methods in abnormal situations based on the contents have the following problems.

The first problem is that the emergency operating procedure manual provides operating methods for initiating events. In general, the number of initiating events of an abnormality is considered to be as follows:
Very many. In conventional devices, in order to respond to various abnormal situations, it is necessary to prepare operating methods for each of these many triggering events. Therefore, the number of operating methods to be prepared is enormous, and the amount of work required and the capacity of the computer's storage device are therefore enormous.

On the other hand, in order to issue a guide when an abnormal situation occurs, it is necessary to determine which event causes the abnormality.

Regarding the classification of this abnormality, since there are a large number of initiating events as described above, the required amount of work and the trough 111 of the computer's storage device 1t are enormous.

The second problem is that in the emergency operation procedure manual, the jXl<transmission method is prepared for a single abnormality development situation. With conventional equipment in which the emergency driver 11 stores the contents of the letter in a computer, the abnormality may progress in a direction different from the prepared progress situation due to a failure of the system or equipment after the abnormality occurs. In such cases, it will be impossible to provide guidance on driving laws.

On the other hand, if operating methods are to be prepared in accordance with the development of various abnormalities assuming system or equipment failures, the required capacity of the computer storage device h1: will be enormous.

The third problem is that the emergency operating procedure manual is originally written in text format.

In other words, it is not clear when to perform an operation (or when to issue an operation guide). For this reason, conventional devices cannot provide operational guidance at appropriate timings as the abnormality progresses.

Therefore, an object of the present invention is to eliminate the drawbacks of the prior art described above, and to provide efficient abnormal operation that can respond to various abnormal situations and their progress, and issue operation guidance at an appropriate timing. The object of the present invention is to provide a guide device.

In order to achieve the above object, the abnormal operation guide device for a nuclear power plant according to the present invention is an abnormal state in which abnormalities occurring in a nuclear power plant are classified in advance based on a combination of the occurrence or non-occurrence of an event that affects the operation method. means for determining which group it belongs to using various signals related to the operating status from the nuclear power plant, and each of the measures that need to be taken to lead the nuclear power plant to the target state. A means for selecting a system to be actually used from system candidates prepared in advance according to the abnormality group, and conditions for starting and ending guidance for each of the countermeasures as described above. The present invention has a means for making a determination using various signals, a means for sequentially extracting a procedure from a pre-prepared system operation procedure in response to changes in the various signals, and a means for displaying information related to each of the means. shall be. In an advantageous embodiment of the present invention, there is provided a means for manually instructing an operator to select a system to be actually used from among systems prepared in advance as candidates for systems to be used, and when the abnormality occurs, Even when the driving unit uses a system different from the selected system, the driving device supports driving &'<. In other words, the abnormal operation guide device of the present invention does not prepare an operation method for each of the many occurrences of abnormalities, but instead prepares operation methods for each occurrence of an event such as loss of external power or pipe rupture that affects the operation method [7]. An operating method is prepared for each abnormality group classified by combination of "failure" and "failure".

In addition, in order to bring a nuclear reactor that has experienced an abnormal situation to a cold shutdown state, it is generally necessary to shut down the reactor, secure the water level,
Measures should be taken to reduce the pressure and remove residual heat, and if necessary, take measures to cool the containment vessel. In the present invention, we have focused on this, and for example, for operations that aim at cold shutdown, we have taken the above-mentioned countermeasures against cold shutdown (hereinafter referred to as "cold shutdown countermeasures" in this specification) and used the countermeasures to take such countermeasures. Consider possible systems and prepare several candidate systems to be used for each cold shutdown measure, depending on the abnormality group. With this method, even if a failure occurs in a system necessary to guide the reactor to the target state during the development of an abnormality, it can be handled by guiding the use of an alternative system.

Further, in the present invention, by using process signals etc. from the BWR plant, guidance on operating methods is shown to the operator at an appropriate timing.

An embodiment of the present invention will be described below with reference to FIG.

The abnormal operation guide device of the BW plant 1 shown in the figure is as follows:
Abnormality group discrimination device 2, cold shutdown countermeasure start/end condition determination device 3, usage system selection device 4, system usage order data file 5, operation procedure creation device 6, operation procedure data /
It is composed of a file 7, a display device 8, a response determination device 9, and a response determination data file 10.

The device of this embodiment is activated by a reactor scram signal indicating nuclear reactor shutdown. In other words, after an abnormal situation occurs, from the moment a reactor scram occurs either automatically by a plant interlock or manually by an operator, this system selects the operating method necessary for cold shutdown and guides the operation. begins to appear.

When the device according to this embodiment is activated by the reactor scram signal, first, the abnormality group discriminator 2 determines whether each event that affects the operation method has occurred (~ or not, depending on the reactor water level etc. from the BWR plant 1). Process signals or signals related to system/equipment status such as valve opening/closing status are used to determine whether or not each event has occurred, and which abnormality group the abnormality belongs to is determined based on whether each event has occurred. .

Events that affect the operation method include those that affect the availability of selection, and those that affect the required capacity of the system, as shown below. We selected water supply system loss of function, main steam isolation valve closure, and loss of external power as the former events, and the safety relief valve stuck open and pipe rupture as the latter events.

The abnormality groups are classified into abnormalities according to the occurrence or non-occurrence of each of the above-mentioned events, and in the case where no pipe breakage occurs, there are 12 groups as shown in FIG. 2. In cases where pipe rupture has occurred, the event of pipe rupture is subdivided by the rupture area and location, and for each subdivided event, it is determined whether other events such as loss of water supply system function have occurred. By considering these combinations, abnormalities are divided into groups. Here, we consider the capacity of the water injection system necessary to secure the water level and the need for depressurization as factors that affect the operation method, and use these two items as indicators to determine whether or not a gas-phase rupture occurs. This was done by determining the fracture area that serves as the dividing line for each liquid phase fracture.

The cold shutdown countermeasure start/end condition determination device 3 determines the start/end conditions for guides regarding cold shutdown countermeasures for each category. The conditions used in this apparatus are shown in FIG. As shown in the figure, the condition for starting the guide for securing water (r'l) is met at the same time as the scram (Ft), that is, the device of this embodiment is started. Once the decision is made, the guide to securing the water level ends.

The starting condition for depressurization is that the reactor water level exceeds the scram water level L3, and the ending condition is that the residual heat removal operation has started. Removal of residual heat begins when the reactor pressure drops below 1.03 MPa through depressurization, and ends when the operator determines that a cold shutdown has occurred. Containment vessel cooling starts when the pressure/temperature IJI of the containment vessel exceeds a predetermined set value, and ends when it falls below the set value.

As described above, the cold shutdown countermeasure start/end condition determining device 3
The system inputs signals related to process quantities etc. from the BWR plant or manual signals from operators, and determines the start and end of guidance for each cold shutdown countermeasure. When this device determines to start guidance for a certain cold shutdown countermeasure, the system to be used is selected by the system selection device 4 to be used for that cold shutdown countermeasure.

The system usage order data file 5 has 111 systems to be used for each cold shutdown countermeasure corresponding to each abnormality group. An example of this order of use is shown in FIG. In the figure, the mark *) indicates one operating mode of the residual heat removal system. FIG. 4 corresponds to abnormality group 5. Here, the order of use is determined in advance through phenomenon analysis or the like. The usage system selection device 4 selects the systems to be used from among the systems prepared in the system usage ranking data file 5 in descending order of usage ranking. For example, for abnormality group 5 shown in FIG. 4, the isolation cooling system and the control rod drive hydraulic system are first selected as systems for securing the water level.

The operating procedure creation device 6 creates an operating procedure for the system selected by the system selection device 4 to be used. In the operating procedure data file 7, safe operations and confirmations for operating each system are prepared with conditions regarding the process amount or the status of the system/crosspiece. Figure 5 shows an example of a cooling system during shutdown11.
In the figure, the symbol T (J-place) indicates the residual heat removal system.
- When the conditions attached to the described operations and confirmations are satisfied, the operations and confirmations are outputted to the display device 8 as a guide.

The response determination device 9 uses the response determination data file 10 to check the plant response after guidance, and determines whether or not it is as expected. The method used for response determination in this device differs depending on the type of operation. For systems used to directly implement cold shutdown measures, the operation and effectiveness of the systems will be confirmed. On the other hand, for other maintenance operations or auxiliary system operations, only the operation of the system will be confirmed.

To confirm system operation, two methods are used: one is to check the component level, such as piping lineup and pump rotation speed, and the other is to check from system characteristics and process quantities. An example of the latter method is to use a pump flow rate-pump head curve to confirm the normal operation of the water level sump system from the reactor pressure and pump flow rate.

To confirm the effectiveness, select the process amount shown in Figure 6 for each cold shutdown measure, and determine whether the value of the process amount at the set time after the operation is greater than (or less than) the set value. method and/or a method of determining whether the value of the process amount is maintained above (or below) the set value after the operation.

If the response determination device 9 determines that the response of the plant is as expected, guidance for that system is continued. On the other hand, if it is determined that the plant response is not as expected, the guide for that system is discontinued, and the system to be used selection device 4 prepares the system as the next usage order in the system usage ranking data file 5. Select the system you are looking for and start being guided through the operating procedures for that system.

Note that the abnormal group is determined on a cycle-by-cycle basis, and when the abnormal group changes, the system to be used is selected from the system usage l1Ei data for the abnormal group.

Next, the operation of the apparatus according to this embodiment will be explained by taking as an example an abnormality caused by loss of water supply. FIG. 7 shows the temporal changes in the reactor pressure and reactor water level after the loss of feedwater occurs, using solid lines and broken lines, respectively.

As water levels drop due to loss of water supply, plant interlocks cause the reactor to scram (6). This scram signal activates the device according to the present embodiment, and first, the abnormality group discriminating device 2 starts determining to which group the generated abnormality belongs. As a result, the water supply system lost its functionality and the main steam isolation valve closed.
It is determined that the abnormality belongs to group 5.

Since the guide start condition (scram signal) for securing the water level is satisfied, when the determination of the abnormal group is completed, the system selection device 4 selects the isolation cooling system and the control rod drive hydraulic system as the systems for securing the water level. is selected. These systems are prepared for group 5 in the system usage l1fi ranking data file 5 as the first usage order for securing the water level.

When the systems are selected, the operating procedure creation device 6 extracts the procedures for operating these systems from the operating procedure data file 7 and shows them on the display device 8.

As a system to ensure the water level, the high-pressure core spray system will automatically start when the water level drops. Since this system has not been selected as a system for securing the water level, the device will guide you to manually stop it.

When the reactor water level recovers and exceeds the scram level (L3) (C1, depressurization tank guidance begins, steam condensation system is selected, and operational procedure guidance is shown.

According to the guide, the high-pressure core spray system was shut down and the operation started 42 min and flushing to prepare this system for use.Q)). In this example, it is assumed that the steam condensing system frying and flushing operations fail. The response determining device 9 determines that this operation has failed and that the response to the t-+, b operation is not as expected (g). Therefore, the relief safety valve prepared in the second order of use is selected as the depressurization reservoir system (I'
l, its operating procedure guide is shown.

By depressurizing operation using the safety relief valve, the reactor pressure was reduced to 1.
When the pressure falls below 0.3 MPa, guide of residual heat removal is started. Following this guide, the operator begins flushing, which is an operation to prepare the cooling system for use during shutdown.

FIG. 8 is a diagram showing another embodiment of the apparatus. The abnormal operation guide device shown in the figure is the device of the first embodiment plus an alarm device 11 and a human power device 2.

The warning device 11 issues a warning to the operator if the operator does not follow the guide issued by the device according to this embodiment. Further, the human power device 12 is used by an operator to manually issue commands to the device of this embodiment.

If the force exerted by the operator on the guide issued by the device is greater than or equal to the trapping force, the response of the plant will be different from what was expected. If the response determination device 9 determines that the runt response is not as expected, there is a possibility that the J army transferee will not follow the guide, so the alarm device 11 will
A warning is issued to the operator. Due to this warning, i-military transfers will
Plant response 75 = I realized that it was not as expected and reconfirmed my actions.

If, as a result of the confirmation, it is found that the device's exit guide and the operation performed by the transferee are the same, the transferee sends a message to that effect from the human-powered device 12 to the device. In this case, the use system selection device 4 selects the system prepared as the next use order as the system to be used in the same manner as in the first embodiment.

On the other hand, if the confirmation results show that the guide issued by the device is different from the operation performed by the operator, if the operator made a mistake in the operation, the operator should be advised to follow the guide issued by the device. Redo the operation.

On the other hand, if the operator intentionally performs a different operation (that is, if the operator uses a system that is different from the system that the equipment is designed to operate on), the operator can manually inform the equipment of this fact. do. If this human power is available, the device displays all system (citation 1t) usage system candidates hli prepared in the j-th data file 5 on the display device 8. If the system is among the displayed systems, operation is determined manually (14) to which of the displayed systems the system in use corresponds to 7.1. The device supports the operator by knowing which system the operator is using, providing guidance for that system, determining responses, etc.

As explained above, according to the present invention, it is possible to respond to various abnormal situations that occur in a nuclear power plant and various progress situations of abnormalities, and safely bring the reactor to the target state at an appropriate time. In addition to being able to provide guidance, it also effectively organizes and categorizes abnormal situations and driving methods, thereby reducing the storage capacity of electronic computers and the amount of work required to create them. Therefore, the use of such an abnormal operation guide device for a nuclear power plant has a significant effect of improving safety and economic efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIG.
Figure 3 is a diagram showing an example of abnormality grouping, Figure 3 is a diagram showing the start and end conditions of the guide for cold shutdown countermeasures, Figure 4 is a diagram showing an example of system usage order data,
Fig. 5 is a chart showing an example of operating procedure data, Fig. 6 is a chart showing process quantities used to judge the plant □ response after guidance, and Fig. 7 is a diagram showing phenomena after an abnormality occurs and a device as an example. FIG. 8 is a block diagram showing the second embodiment. DESCRIPTION OF SYMBOLS 1... BW plant, 2... Abnormality group discrimination device, 3... Cold shutdown countermeasure start/end condition determination device, 4
...Use system selection device, 5...System use order data file, 6...Driving procedure creation device, 7...Driving procedure data file, 8...Display device, 9...Response Judgment device, 10... response judgment data file,
11...House 7 Kasumi Mutsumi value)

Claims (1)

[Claims] 1. The nuclear power plant determines to which of the abnormality groups the abnormality that has occurred in the nuclear power plant belongs to, which is pre-classified based on the combination of the occurrence or non-occurrence of events that affect the operating method. As a system to be used for each of the means for determining using various signals regarding the operating state of the nuclear power plant and the measures that need to be taken to lead the nuclear power plant to the target state, A means for selecting a system to actually be used from among prepared system candidates, a means for determining conditions for starting and ending guidance for each of the countermeasures using the various signals, What is claimed is: 1. An abnormal operation guide device for a nuclear power plant, comprising: means for sequentially extracting procedures from the operating procedures of the system in response to changes in the various signals; and means for displaying information related to each of the means. 2. It has a means for manually selecting one from among the systems prepared in advance as candidates for the system to be used by all system operators who will actually use the system, and the abnormal operation system Claim 17, characterized in that the system supports the operator even when the operator uses the system.
1. Abnormal operation guide device for a nuclear power plant as described in item 1.