JPH0786552B2 - Recirculation flow control device and method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a recirculation flow rate control device, a reactor plant and a recirculation flow rate control method, and particularly to a boiling water nuclear reactor having an internal pump. A recirculation flow rate control device, a nuclear reactor plant and a recirculation flow rate control method suitable for the above are provided.

[Conventional technology]

The reactor power of a boiling water reactor is controlled by controlling the rod operation and adjusting the flow rate of the cooling water supplied to the core. As shown in JP-A-59-107298, supply of cooling water to the core is carried out by a recirculation pump provided in a recirculation pipe connected to a reactor pressure vessel, and JP-A-60-
As disclosed in Japanese Patent No. 138495, there is an internal pump provided in a reactor pressure vessel.

Both of the boiling water reactor using the recirculation pump and the boiling water reactor using the internal pump, when the reactor power is in the rated state, abnormal in the plant of the boiling water reactor (for example, In the event of load shedding, turbine trips and reactor pressure high (80.1 kg / cm ² or more), all recirculation pumps or all internal pumps are tripped. Due to this trip, the core flow rate is reduced, and the reactor power is rapidly reduced to a low power. An example of tripping all recirculation pumps is disclosed in JP-A-59-10.
No. 7298 publication.

[Problems to be Solved by the Invention]

If all pumps (recirculation pumps or internal pumps) that supply cooling water to the core are tripped as in the conventional case, the reactor power is rapidly reduced to a low power as described above. Such characteristics effectively function to ensure the safety of the reactor even during abnormal times.

However, the inventor examined in detail the characteristics of the reactor in the case of tripping all the recirculation pumps and all the internal pumps at the time of an abnormality, and as a result, a new problem was found when all the internal pumps tripped. I found it to happen. The problem is that when all internal pumps are tripped, the heat removal capacity from the fuel rods loaded in the core is significantly reduced immediately after tripping, compared with the case where all recirculation pumps are tripped. is there. It has been found that this is caused by the inertia of the internal pump being less than the inertia of the recirculation pump. That is, even if the recirculation pump is tripped, since the inertia is large, the rate of decrease in the number of revolutions of the recirculation pump after the trip is relatively gentle. Therefore, the cooling water supplied to the core does not drastically decrease to the extent that it hinders the heat removal of the fuel rod even after all the recirculation pump trips.

However, the rate of decrease of the rotational speed after trip in the internal pump having a small inertia is significantly larger than that in the recirculation pump. Therefore, when all the internal pumps trip, the flow rate of the cooling water supplied to the core decreases sharply immediately after the trip. This is the reason why heat removal from the fuel rods is inadequate when all internal pumps trip.

It is an object of the present invention to provide a recirculation flow rate control device and method that can reduce the reactor power and also cool the fuel.

[Means for Solving the Problems]

According to the present invention, an internal pump to be tripped is selected according to the type of abnormal event and the operating state of the internal pump.

[Action]

Since some internal pumps that are tripped when the plant is abnormal are selected, the reactor output can be reduced without tripping all internal pumps and the fuel can be sufficiently cooled.

Calculate the number of operating internal pumps and select some internal pumps to trip in the event of a plant failure based on the number of operating internal pumps. The reactor output can be reduced and the fuel can be sufficiently cooled.

Since some internal pumps to be tripped when there is an abnormality in the plant are selected based on the operating conditions of the internal pumps and abnormal events, the reactor output can be appropriately adjusted even if the abnormal events are different. The amount can be reduced and the fuel can be sufficiently cooled.

The capacity of the computer can be reduced by configuring the means for determining the operating state and the abnormal event of the internal pump and the means for selecting the internal pump to be tripped when the plant is abnormal by separate computers.

Means for storing the operating state of the internal pump and the knowledge defining the internal pump to be tripped corresponding to the abnormal event, and the operating state of the internal pump and the plant abnormality obtained by using this knowledge Inference means that makes inferences based on events and selects some internal pumps that trip when an abnormality occurs in the plant,
By providing a means for tripping the selected internal pump, the pump to be tripped can be selected in a short time after an abnormality occurs.

Some internal pumps that need to be tripped when the plant is in an abnormal state are selected when the plant is in a normal state, and the internal pumps that are selected from the storage means based on the abnormal event that occurs when the plant is in an abnormal state are selected. Since the tripping signal is output to the null pump, the number of processing events at the time of abnormality is reduced, and the pump to be tripped can be selected in a short time after the abnormality occurs.

〔Example〕

A recirculation flow rate controller, which is a preferred embodiment of the present invention applied to a boiling water reactor plant, will be described with reference to FIG.

The boiling water reactor plant to which this embodiment is applied has ten internal pumps (hereinafter, referred to as RIPs) 1 to 10. RIPI-10 are provided in the reactor pressure vessel 11 and are annularly arranged around a core shell 13 surrounding the core 12 as shown in FIG. The rotary shaft provided on the RIP is directly connected to the motor. In FIG. 1,
It is shown as an example that RIP1 is connected to the motor M1 and RIP10 is connected to the motor M10.

The cooling water supplied into the core 12 at the RIPs 1 to 10 becomes steam in the core 12. This steam is guided to the turbine 14 through the main steam pipe 16 connected to the reactor pressure vessel 11. Turbine
The steam exhausted from the turbine 14 after giving a rotational force to the 14 is condensed in the condenser 15. Generator 21 and turbine 14
Connected to. A main shutoff valve 17 and a main steam control valve 18 are installed in the main steam pipe 16. A turbine bypass pipe 19 provided with a bypass valve 20 connects the main steam pipe 16 and the condenser 15.

Wiring 37,3 connected to the local power source connected to the generator 21
8, 39 and 40 are connected to circuit breakers 33, 34, 35 and 36, respectively, as shown in FIG. The pipes 37 to 40 are connected not only to the generator 21 but also to an external electric power system in preparation for startup of the nuclear reactor. The wirings 22 and 23 are connected to the circuit breaker 33. The wirings 24 and 25 are connected to the circuit breaker 34. Similarly,
The wirings 28 to 30 are connected to the circuit breaker 35, and the wirings 30 to 32 are connected to the circuit breaker 36. The wiring 22 is connected to the inverter IV1 that supplies a current to the motor M1. The wiring 32 is connected to the inverter IV10 that supplies current to the motor M10.

Although not shown, the wiring 23 is connected to an inverter IV2 that supplies a current to the motor M2 connected to the RIP2. rip
Inverter IV3 supplying current to motor M3 connected to 3
A wire 24 is connected to. Wiring 25 is inverter IV4
Connected to. This inverter IV4 supplies current to the motor M4 connected to RIP4. Motor connected to RIP5
The inverter IV5 connected to M5 is connected to the wiring 27. The wiring 28 is connected to an inverter IV6 that supplies current to the motor M6 attached to the RIP6. For the inverter IV7 that supplies current to the motor M7 connected to RIP7, wire 29
Are connected. The inverter IV8 connected to the motor M8 connected to the RIP8 is connected to the wiring 30. Wiring 31 is RIP
Inverter I supplying current to motor M9 mounted on 9
Connected to V9.

A pressure gauge 41 for detecting the pressure of steam is installed in the main steam pipe 16. A tachometer 42 for detecting the rotation speed of the turbine 14 (the rotation speed of the generator 21) is provided. 43 is a power load unbalance relay, which inputs the output signals of the pressure gauge 41 and the tachometer 42. Power load unbalance relay 43
When the difference between the output signals including the dimensions is equal to or more than a predetermined value, the operation is performed and the operation signal is output. An opening / closing detector 44 for detecting opening / closing of the main stop valve 17 is installed. A power meter 26 is provided in each of the inverters IV1 to IV10. Each of these voltmeters 26 detects the power supply voltage of the corresponding inverter. 50 is a central control panel.
Although not shown, the central operation panel 50 is provided with not only operation buttons but also display devices such as a display and a meter for displaying the plant status. The process computer 45 inputs the operation signal of the power load unbalance relay 43, the output signal of the open / close detector 44, the output signal of the voltmeter 26, and the like. The trip pump selector 46 has an inference means 47,
It has a knowledge database 48 and a knowledge constructing means 49.
The trip pump selector 46 is composed of a small-sized computer or a micro computer.

In the boiling water reactor to which this embodiment is applied, the core flow rate increases and the reactor power increases when the rotational speeds of RIP1 to 10 are increased. On the contrary, when the rotational speeds of RIP1 to 10 are decreased, the core flow rate is decreased and the reactor power is decreased. The rotation speeds of RIP1 to 10 are increased or decreased by changing the frequency of the current in the corresponding inverter.

In the normal state of the boiling water plant, the circuit breakers 33 to 36 are closed and the drive currents are supplied to the motors M1 to M10. Therefore, the RIPs 1 to 10 are rotated and the cooling water is supplied to the core 12. At this time, the reactor power is assumed to be 100% of the rated power.

The process computer 45 executes the processing procedure shown in FIG. In addition to this processing procedure, the process computer 45 executes processing such as control of equipment of the boiling water reactor plant and measurement data. The processing based on the processing procedure of FIG. 3 will be described in detail below. Step 51 grasps the operating state of the RIP based on the input output signal of each voltmeter 26. That is, if there is a number of RIPs in operation and a RIP that has stopped due to a failure, the number of that RIP is known. The determination as to whether the RIP is in the operating state or in the stopped state is made based on whether or not the power supply voltage measured by the voltmeter 26 is equal to or higher than a predetermined value. When the RIP is in operation, the power supply voltage is above the specified value.

It is determined whether or not an abnormality has occurred in the plant (step 52). If no abnormality occurs, steps 51 and 52 are re-executed. Presence or absence of an abnormality is determined based on the process data measured in the plant. That is, when the power load unbalance relay 43 outputs an operation signal, the opening / closing detector 44 outputs a closing signal, or the pressure gauge 41 outputs a measured value of 80.1 kg / cm ² or more, the step The judgment of 52 becomes "YES". Step 52
If the judgment is "YES", what is the abnormal event occurring is specified (step 53). The identification of abnormal events is to identify which of the abnormalities, such as turbine trips, load shedding, and reactor pressure highs that should trip the RIP, corresponds to the abnormalities that have occurred. When the power load unbalance relay 43 outputs an operation signal, load interruption occurs, and when the open / close detector 44 outputs a closing signal, a turbine abnormality occurs, and the measured value of the pressure gauge 41 is 80.1 kg / cm ² or more. A high reactor pressure is occurring at Step 54
Is the information of the abnormal event and the information of the RIP operation status (R
IP) Output the number of operating units and the number of stopped RIP).

These output information are input to the inference means 47 of the trip pump selector 46. The inference means 47 executes processing based on the processing procedure shown in FIG. The inference means 47 does not execute the processing procedure of FIG. 4 when the process computer 45 does not output the information on the abnormal event and the RIP operation information, that is, when the abnormality does not occur in the boiling water reactor plant. The knowledge database 48 stores the knowledge of the IF-THEN production type, that is, the rule, which includes the condition part and the conclusion part shown in FIGS. These rules specify the circuit breaker to be opened, that is, the RIP to be tripped, based on the abnormal event and the operation information of the RIP. FIG. 5 shows the rule when the abnormal event is “load shed”, and FIG. 6 shows the rule when the abnormal event is “turbine trip”. These rules are created based on the characteristics shown in FIGS. 7 and 8. That is, the number of RIP trips that can maximize the effect of alleviating the condition after the occurrence of an abnormality varies depending on the number of operating RIPs. The case of load shedding shown in Fig. 7 will be explained by tripping four operating RIPs when operating 10 RIPs and tripping three operating RIPs when operating 9 RIPs. In addition, the above-mentioned mitigation effect can be maximized by tripping the two RIPs in operation when 8 RIPs are in operation. FIG. 8 shows the case of a turbine trip as well as load shedding. 7th
The characteristics shown in FIG. 8 and FIG. 8 are findings newly obtained by the inventor. The number of RIPs to be tripped differs due to the difference in abnormal events.

Taking as an example the case where the load is cut off while RIP4 is stopped due to a failure and the remaining 9 RIPs are operating,
The function of the trip pump selector 46 will be described in detail. The process computer 45 uses "load shedding" as an abnormal event and "RIP 9 unit operation and RIP 4 failure" as RIP operation information.
To the trip selector 46. The inference means 47 inputs these pieces of information (step 55). At step 56,
The knowledge database 47 is searched for a rule having “load cutoff” and “RIP9 unit operation and RIP4 failure” as the condition parts. By this search, the rule 103 shown in FIG. 5 is searched. Next, at step 57, an open signal for opening the circuit breaker 35 shown in the conclusion of the retrieved rule 103 is output. This open signal is transmitted from the trip pump selector 46 to the circuit breaker 35, and the circuit breaker 35 is opened. By this, 3 of RIP5-7
The stand is tripped, and the effect of alleviating the condition after load shedding can be maximized during operation of 9 RIP units. That is, the reactor output can be reduced to a safe state after the load is cut off, and heat can be sufficiently removed from the fuel rods in the core. Even if a turbine trip occurs, the corresponding RIP can be tripped,
The same effect as in the case of load shedding occurs.

According to this embodiment, not all RIPs are tripped when an abnormality occurs in a boiling water reactor plant, but a predetermined number of RIPs are tripped. It is possible to reduce the output to below the output and to sufficiently remove heat from the fuel rod.
Further, in this embodiment, the number of RIPs to be tripped in the event of an abnormality can be selected in correspondence with the number of RIP operating units, so that the effect of mitigating the state after the occurrence of an abnormality can be maximized to the maximum number of RIP operating units. . Since the number of RIPs to be tripped in the event of an abnormality can be appropriately selected for each abnormal event, it is possible to obtain an appropriate mitigation effect that matches the abnormal event that has occurred. In this embodiment, by obtaining the abnormal event and the RIP operation information, it is possible to open the corresponding breaker in a short time and trip the predetermined RIP. Therefore, even if an abnormality occurs, the boiling water reactor plant can be brought into a highly safe state in a short time. Since the trip pump selector 46 is provided separately from the process computer 45, it is not necessary to increase the capacity of the process computer 45 that executes various arithmetic processes required for control and monitoring. Since the circuit breaker to be opened is selected based on the abnormal event information at the time of the abnormal occurrence and the RIP operation information, it is possible to accurately determine the RIP to be tripped that matches the abnormal event and the RIP operating state.

In this embodiment, the knowledge construction means is provided in the trip pump selector 46.
Since 49 is provided, a new rule can be constructed and a rule stored in the knowledge database 48 can be modified. In particular, the number of RIPs to be tripped differs depending on the average burnup of the core even if the abnormal event and the number of RIP operating are the same. That is, immediately after loading the new fuel assembly, at the beginning of the fuel cycle with a large excess reactivity (small core average burnup), the number of RIP trips is small and the end of the fuel cycle with a small excess reactivity (high core average burnup). )
Then, it is necessary to increase the number of RIP trips. The characteristics shown in FIGS. 7 and 8 are those at the end of the fuel cycle.
At the beginning of the fuel cycle, the number of trips of RIP corresponding to each operating number is about 1 or 2 less than the number of trips shown in Figs. 7 and 8. To correct the number of RIP trips in this way, the operator inputs necessary data from the central operation panel 50, and the knowledge constructing means 49 creates a new necessary rule or corrects an existing rule. The newly created or modified rule is stored in the knowledge database 48. As described above, by changing the number of RIPs to be tripped during the operation of one fuel cycle, it is possible to obtain an appropriate mitigation effect considering the average burnup of the core. Even if the type of fuel assembly loaded in the core changes, the number of RIPs to be tripped also changes. Therefore, the knowledge construction means 49 creates a new rule (or modifies an existing rule according to the operator's instruction). ) Is carried out.

In other words, the trip pump selector 46 of the present embodiment can be said to be means for selecting a RIP that continues operation without tripping even if an abnormality occurs.

A recirculation flow rate control system according to another embodiment of the present invention will be described with reference to FIG. In this embodiment, a tachometer 60 is provided in place of the voltmeter 26 of the embodiment shown in FIG. Tachometer
The motors 60 are installed in the motors M1 to M10, respectively. Each tachometer 60 detects the rotation speed of the corresponding motor among the motors M1 to M10. Process computer 45, step 51
The number of RIPs operating based on the output of each tachometer 60 input in (Fig. 3) and the RIP stopped due to a failure
Understand the number of RIPs and the number of the RIP stopped due to a failure. If the rotation speed measured by the tachometer 60 is equal to or higher than the predetermined value, it is determined that the RIP is operating normally. This embodiment produces the same effects as the embodiment of FIG. Further, in the present embodiment, since the number of operating RIPs and the failed RIP are grasped by the rotational speeds of the motors M1 to M10, the grasping of these is more accurate than grasping based on the power supply voltage of FIG. Even if the wiring that connects the inverter and the motor is disconnected and the motor does not rotate, it can be detected.

A recirculation flow rate control device as another embodiment of the present invention will be described with reference to FIG. In this embodiment, the trip pump selector 46 in the embodiment of FIG. 1 is replaced by the trip pump selector 61.
In addition, the processing procedure executed by the process computer 45 is changed from the processing procedure shown in FIG. 3 to the processing procedure shown in FIG. The trip pump selector 61 is a calculation means 62.
And a memory 63. The memory 63 has memory areas A, B and C (not shown). The memory area A stores the processing procedure shown in FIG.

The operation of this embodiment will be specifically described based on the processing procedure shown in FIG. 11 and FIG.

The process computer 45 executes the processing of steps 51 and 52 described above. If the determination in step 52 is "NO", RIP operation information and a normal signal are output (step 6).
Four). If the determination in step 52 is "YES", step 52
The process of 53 is executed, and the abnormal signal and the obtained abnormal event are output (step 65).

The calculation means 62 of the trip pump selector 61 executes the processing procedure of FIG. The memory 63 has a memory area B
It stores the information of FIGS. 14 and 15. 13 and 14 show the circuit breaker to be opened depending on the operating condition of the RIP. Figure 13 is for load shedding, and Figure 14 is for turbine trips. A circle indicates a circuit breaker to be opened. The computing means 62 inputs the information output from the process computer 45 (information output in step 64 or 65) in step 66. Next, it is determined whether or not an abnormality has occurred in the boiling water reactor plant based on the input normal signal or abnormal signal (step 67). If the determination at step 67 is "NO", then step 68 is executed. That is, the circuit breaker to be opened, that is, the RIP to be tripped is selected for each abnormal event from the information stored in the memory information B of the memory 63 based on the input operation information of the RIP. The selected circuit breaker to be opened, that is, the RIP to be tripped is stored in the memory area C of the memory 63 for each abnormal event.
Remember (step 69). For example, when the process computer 45 determines in step 51 that the number of operating RIPs is 9 and the RIP 7 is out of order, in step 68, the circuit breaker 36 for load shedding from FIG. (B)
To find the circuit breaker 33 for the turbine trip.
The circuit breaker 36 thus retrieved is stored in the memory area C in correspondence with the load shedding and the circuit breaker 33 in correspondence with the turbine trip.

When the process computer 45 outputs an abnormal signal based on step 65, the determination at step 67 is "YES", and the processing at step 70 is executed. That is, the circuit breaker to be opened, that is, the RIP to be tripped is searched from the memory area C based on the information on the abnormal event input at step 66. If the abnormal event input at step 66 is the "turbine trip", the memory circuit C is searched for the circuit breaker 33. An open signal is output to the found breaker 33 (step 71).

The breaker 33 that has received the open signal is opened. Because of this, RI
The supply of current to P1 and 2 is stopped and RIP1 and 2 are tripped.

This embodiment can obtain the same effects as those in FIG. The data in FIGS. 13 and 14 are prepared based on the characteristics in FIGS. 7 and 8. These data are calculated based on the operator's instruction from the central control panel 50.
62 can be modified and added. In this embodiment, the circuit breaker to be opened corresponding to the abnormal event in the normal state of the plant is selected, and when the abnormality occurs, the one corresponding to the abnormal event is searched from the selected circuit breakers. The time until the predetermined breaker is opened after the occurrence of the abnormality is set shorter than that in the embodiment shown in FIG. This is desirable from the viewpoint of improving the safety of boiling water reactor plants.
Although the present embodiment does not consider the RIP operation information at the time of occurrence of an abnormality, since the processing of Steps 66 to 69 in a normal state is repeated in an extremely short cycle, the RIP operation state at the time of occurrence of an abnormality is And the RIP operating state used for step 68 performed immediately before the occurrence of the abnormality is substantially the same.

The recirculation flow rate control device according to another embodiment of the present invention is
This will be described with reference to FIGS. In this embodiment, the process computer 45 in the embodiment shown in FIG. 10 executes the processing procedure shown in FIG.
The processing procedure shown in the figure is executed. The memory 63 is the 16th
The procedure of FIG. 17 and FIG. 17 is stored. FIG. 16 is for load shedding, and FIG. 17 is for turbine trips. These processing procedures are shown in FIG. 7 and FIG.
It is created to reflect the characteristics of the figure. The process of the process computer 45 has been described in the embodiment of FIG. When an abnormality occurs in the plant, the information on the abnormal event and the operation information of the RIP are input to the computing means 62 (step 5).
Five). Next, the processing procedure corresponding to the abnormal event that has occurred is retrieved from the memory 63 (step 72). If the abnormal event that occurred is load shedding, the processing procedure shown in FIG. 16 is selected. In step 73, the searched processing procedure (for example, the 16th step) is searched.
Figure) is used to find the circuit breaker to open that corresponds to the operating information of the RIP. For example, if 8 RIPs are operating and RIPs 1 and 2 fail and load shedding occurs, the 16th
The circuit breaker 34 is selected as the circuit breaker to be opened based on the procedure shown in the figure. Step 74 outputs an open signal to the selected breaker.

By opening the circuit breaker 34, the RIPs 3 and 4 are tripped.

This embodiment produces the same effect as the embodiment shown in FIG. However, since the circuit breaker to be opened is sought based on the processing procedure shown in FIGS. 16 and 17 after the occurrence of an abnormality, the time until the circuit breaker to be opened is selected is slightly shorter than that in the embodiment of FIG. become longer. However, there is no particular problem in terms of reactor safety.

A recirculation flow rate control system according to another embodiment of the present invention will be described with reference to FIG. In the present embodiment, the trip pump selector 46 of FIG. 1 is removed and its function is added to the process computer 45 for controlling the plant equipment and the like. That is, the process computer 75 of this embodiment is
It has the functions of both the process computer 45 and the trip pump selector 46 in the embodiment of FIG. The process computer 75 has steps 51, 52, 5 shown in FIG.
Perform the procedure with 3,56 and 57. This processing procedure is a combination of the processing procedures of FIGS. 3 and 4.

This embodiment can obtain the same effect as that of the embodiment shown in FIG. Moreover, this embodiment is based on the trip pump selector 46.
Therefore, the number of wirings for signal transmission is reduced as compared with the embodiment shown in FIG. However, the process computer
The capacity of 75 must be larger than that of the process computer 45. The process computer 75, like the trip pump selector 46, has a knowledge correction / creation function based on an instruction from the central operation panel 50.

The idea of this embodiment can be applied to each of the above-described embodiments. For example, in FIG. 10, the function of the trip pump selector 61 is added to the process computer 45.

A recirculation flow rate control device as another embodiment of the present invention will be described with reference to FIG. In this embodiment, unlike each of the above-described embodiments, the operator selects the breaker to be opened. In the present embodiment, the trip pump selector 46 is removed from the configuration of the embodiment of FIG. 1 and circuit breaker open setting devices (for example, switches) 76 to 79 are newly provided. The circuit breaker open setting devices 76 to 79 are provided corresponding to the circuit breakers 33 to 36 as shown in FIG. That is, one circuit breaker open setting device and circuit breaker are provided in pairs. Further, a process computer 80 is provided instead of the process computer 45.

The process computer 80 inputs the output signals of the voltmeter 26, the power load unbalance relay 43, the open / close detector 44, and the like, and in the embodiment shown in FIG.
Most of the information that is entered by is entered. The process computer 80 determines whether or not an abnormality has occurred in the plant based on the input process data of the plant. Such a process computer 80 outputs a circuit breaker open signal when an abnormality that trips the RIP occurs. This breaker open signal is transmitted to each breaker 33 to 36 corresponding to the breaker open setter via the breaker open setters 76 to 79, respectively. When the breaker open setting device is opened, the breaker open signal is not transmitted to the breaker.

The process computer 80 inputs the output of each voltmeter 26, obtains the number of normally operating RIPs and the number of the failed RIP, if any, and outputs it to the central operation panel 50. The central operation panel 50 displays information on the operating state of the RIP on the display 81. The operator operates the setting button 82 to set the circuit breaker to be opened based on the RIP operation information displayed on the display 81. A closing signal is output to the circuit breaker open setting device specified by operating the setting button 82. The circuit breaker open setting device that receives this closing signal is closed, and the circuit breaker open setting device that does not input the closing signal remains open.

Setting button 82 and circuit breaker open setting device 76 to
Reference numeral 79 corresponds to the trip pump selector 46.
The circuit breaker open setting devices 76 to 79 are storage means for storing circuit breakers to be opened at the time of abnormality, that is, RIPs to be tripped at the time of abnormality. The operation of closing the circuit breaker open setting device corresponding to the circuit breaker to be opened when an abnormality occurs with the setting button 82 is
It is done in advance when the plant is normal.

After that, when an abnormality occurs in the boiling water reactor plant, the circuit breaker open signal output from the process computer 80 is closed as described above to the predetermined circuit breaker via the circuit breaker open setting device. Reportedly.

In this embodiment, it is easy to set the circuit breaker to be opened corresponding to the RIP operating state, but it is difficult to set the circuit breaker for each abnormal event, which leads to complication of equipment. Therefore, a circuit breaker that should be opened in common for each abnormal event is set so as not to impair safety for each abnormal event.

For example, assuming that the setting of the circuit breaker to be opened for the turbine trip shown in FIG. 14 is used in this embodiment, the specific operation of this embodiment will be described. Display 80 by the process of Process Computer 80, "RIP
It is assumed that the number of operating units is 8 and RIP1 and 4 are broken. ” Looking at this display, the operator looks for the breaker to be opened in the event of an abnormality from the manual showing the relationship shown in FIG. In this case, the circuit breakers 33 and 34 correspond to this. The operator operates the setting button 82 so that the circuit breakers 33 and 34 are opened at the time of abnormality, and outputs an open signal to the circuit breaker open setting devices 76 and 77. When an abnormality occurs, the circuit breaker open signal output from the process computer 80 is transmitted to the circuit breakers 33 and 34 via the circuit breaker setters 76 and 77 that are closed. Circuit breakers 33 and 34 are opened and RIPs 2 and 3 are tripped.

In this embodiment, the same effect as that of the embodiment of FIG. 1 can be achieved although some manual operation by the operator is involved. However,
It is not possible to set the RIP that should trip in response to an abnormal event.

〔The invention's effect〕

Since some internal pumps to be tripped when there is an abnormality in the plant are selected based on the operating conditions of the internal pumps and abnormal events, the reactor output can be appropriately adjusted even if the abnormal events are different. The amount can be reduced and the fuel can be sufficiently cooled.

The capacity of the computer can be reduced by configuring the means for determining the operating state and the abnormal event of the internal pump and the means for selecting the internal pump to be tripped when the plant is abnormal by separate computers.

Means for storing the operating state of the internal pump and the knowledge defining the internal pump to be tripped corresponding to the abnormal event, and the operating state of the internal pump and the plant abnormality obtained by using this knowledge Inference means that makes inferences based on events and selects some internal pumps that trip when an abnormality occurs in the plant,
By providing a means for tripping the selected internal pump, the pump to be tripped can be selected in a short time after an abnormality occurs.

Some internal pumps that need to be tripped when the plant goes into an abnormal state are selected when the plant is in a normal state, and the internal pumps selected from the storage means are selected based on the abnormal event that occurs when the plant goes into an abnormal state. Since the tripping signal is output to the null pump, the number of processing events at the time of abnormality is reduced, and the pump to be tripped can be selected in a short time after the abnormality occurs.

[Brief description of drawings]

FIG. 1 is a block diagram of a recirculation flow rate control device which is a preferred embodiment of the present invention, and FIG. 2 is RI in the reactor pressure vessel of FIG.
FIG. 3 is a plan view showing the arrangement state of P, FIG. 3 is an illustration of the processing procedure executed by the process computer of FIG. 1, and FIG. 4 is executed by the trip pump selector of FIG. Explanatory diagram of the processing procedure, FIGS. 5 and 6 are explanatory diagrams of the rules stored in the trip pump selector of FIG. 1,
FIGS. 7 and 8 are characteristic diagrams showing the relationship between the number of RIPs to be tripped and the effect of alleviating the condition after the occurrence of an abnormality in each RIP operation number in load trip and turbine trip, FIG. 9, FIG. , FIG. 18 and FIG. 20 are configuration diagrams of a recirculation flow rate control device according to another embodiment of the present invention, FIG. 11 is an explanatory diagram of processing procedures executed by the process computer of FIG. 10, and FIG. Fig. 10 is an explanatory diagram of the processing procedure executed by the trip pump selector in Fig. 10, and Figs. 13 and 14 are the RIP operation numbers for the load shedding and turbine trips stored in the trip pump selector in Fig. 10. Explanatory diagram showing each circuit breaker to be opened, FIG. 15 is an explanatory diagram of a processing procedure executed by the trip pump selector of FIG. 10 in another embodiment of the present invention,
16 and 17 are explanatory diagrams of the processing procedure corresponding to the abnormal event (load cutoff and turbine trip) shown in FIG. 15, and FIG. 19 is the processing procedure executed by the process computer of FIG. Is. 1-10 Internal pump, 11 Reactor pressure vessel, 12 Core, 14 Turbine, 17 Main shut-off valve, 26
...... Voltmeter, 33 to 36 ...... Breaker, 41 ...... Pressure gauge, 42,60
...... Tachometer, 43 …… Power load unbalance relay,
45,75,80 …… Process computer, 46,61 …… Trip pump selector, 76 ～ 79 …… Circuit breaker open setting device, M1 ～ M10
...... Motor, IV1 to IV10 …… Inverter.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G21D 3/04 B 9117-2G

Claims (5)

[Claims] 1. An apparatus for controlling a recirculation flow rate of a nuclear reactor comprising a plurality of internal pumps, means for determining an operating state of the internal pump and a type of abnormal event occurring in a nuclear reactor plant, A means for selecting a part of the internal pumps to be tripped in the event of an abnormality of the nuclear reactor plant, and a means for tripping the selected internal pumps, corresponding to the operating state of the null pump and the type of the abnormal event. A recirculation flow rate control device characterized by being provided. 2. An apparatus for controlling a recirculation flow rate of a nuclear reactor having a plurality of internal pumps, wherein a part of the internal pumps that need to be tripped when the reactor plant is in an abnormal state is provided. Means for selecting when the reactor plant is normal, means for storing the selected internal pump in association with an abnormal event of the reactor plant, and an abnormality that occurs when the reactor plant is in an abnormal state And a means for outputting a trip signal to the internal pump selected from the storage means based on the type of event. 3. An apparatus for controlling a recirculation flow rate of a reactor equipped with a plurality of internal pumps, wherein a plurality of circuit breakers controlling a connection between the internal pump and a power source and a reactor plant are in an abnormal state. Means for selecting the circuit breaker connected to the internal pump that needs to be tripped when it becomes normal during normal operation of the reactor plant,
Means for storing the selected circuit breaker in association with an abnormal event of the reactor plant, and for the circuit breaker selected from the storage means based on the abnormal event occurred when the abnormal state And a means for outputting an open signal. 4. A method of controlling a recirculation flow rate of a nuclear reactor having a plurality of internal pumps, wherein a part of the internal pumps for determining the number of operating internal pumps and tripping when an abnormality occurs in a nuclear reactor plant. Is selected based on the type of abnormal event and the number of operating internal pumps, and the selected internal pump is tripped when the plant is abnormal. 5. A method of controlling a recirculation flow rate of a nuclear reactor having a plurality of internal pumps, wherein a part of the internal pumps that need to be tripped when an abnormal state of a nuclear reactor plant is provided. Select when the plant is normal, store the selected internal pump in association with the type of abnormal event of the plant, the storage based on the type of abnormal event that occurs when the plant is in an abnormal state A recirculation flow rate control method, comprising outputting a signal for causing the internal pump selected from the means to trip.