JP7076394B2 - Reactor output controller - Google Patents

Description

The present invention relates to an apparatus for controlling the output of a nuclear reactor in a nuclear power plant, and more particularly to a reactor output control apparatus for controlling a core flow rate increase at the start of a boric acid water injection system in a boiling water reactor.

As an example of a boiling water reactor capable of effectively applying a negative reaction rate by boric acid water injected into a reactor pressure vessel, in Patent Document 1, it is arranged above the core and inside the shroud. Core spray sparger, low-pressure core spray system and low-pressure water injection system connected to the core spray spurger to supply cooling material, and high-pressure core spray system, reactor isolation cooling system that supplies cooling material to the outside of the shroud, and boric acid. It is equipped with a borate water injection nozzle that injects water into the reactor pressure vessel, and the control device controls so that the coolant flow outside the shroud is greater than or equal to the coolant flow inside the shroud when injecting borate water. A boiling water reactor is described.

Japanese Unexamined Patent Publication No. 2016-40087

Reactors installed in nuclear power plants can be broadly divided into two types: boiling water reactors and pressurized water reactors.

Of these, in boiling water reactors, although extremely rare, it is assumed that a reactor shutdown function loss event occurs in which control rods are not fully inserted even though an event that requires scramming occurs for some reason. It also has an alternative reactivity control function using a boric acid water injection system (SLC: Standby Liquid Control System).

Due to this function of SLC, an aqueous solution of sodium pentaborate (hereinafter referred to as boric acid water) is injected into the reactor. When this boric acid water reaches the core, neutrons are reduced by neutron absorption by boron, and the fission reaction of the fuel loaded in the reactor is suppressed (negative reactivity is applied). This makes it possible to shift the reactor to a subcritical state in the event of a reactor shutdown function loss event.

The technique described in Patent Document 1 has been proposed as a boiling water reactor capable of effectively mixing boron contained in boric acid water injected into such a reactor pressure vessel.

As described above, it is known that boric acid water is injected into the core by a boric acid water injection system when a reactor shutdown function loss event occurs in a boiling water reactor.

Here, especially in a boiling water reactor in which boric acid water is injected from the lower part of the core, boric acid water has a higher density than the cooling material, and boric acid water has a higher temperature than the cooling material. There is a problem that boric acid water tends to fall to the lower part of the reactor pressure vessel without reaching the core because of its low value.

At this time, if the core flow rate becomes extremely low, such as when the recirculation pump stops and the reactor water level drops, the inflow of boric acid water into the core should be increased. Is desirable.

The present invention provides a reactor output control device capable of allowing boron contained in boric acid water to be injected into a reactor pressure vessel to flow into the core to further promote mixing.

The present invention includes a plurality of means for solving the above problems, and one example thereof is a reactor output control device in a boiling water reactor, wherein the boiling water reactor has a reactor pressure. The boric acid water via the container, the boric acid water storage tank, the boric acid water injection nozzle for injecting the boric acid water in the boric acid water storage tank into the reactor pressure vessel, and the boric acid water injection nozzle. The reactor output control device is provided with a boric acid water injection pump that sends the reactor pressure vessel to the reactor pressure vessel and a recirculation pump that circulates the cooling material in the reactor pressure vessel. The recirculation pump was started on the condition that the cooling material water level in the reactor was lower than the preset value and the boric acid water was injected into the reactor pressure vessel. When the output of the boiling water reactor falls below a preset value, or the time required for all the boric acid water stored in the boric acid water storage tank to be injected into the reactor pressure vessel has elapsed. After that, the recirculation pump is stopped .

According to the present invention, it is possible to provide a reactor output control device capable of allowing boron contained in boric acid water to be injected into a reactor pressure vessel to flow into the core to further promote mixing. Issues, configurations and effects other than those mentioned above will be clarified by the description of the following examples.

It is an overall schematic block diagram and circuit diagram of the reactor power control apparatus which concerns on one Embodiment of this invention. It is a flow chart which shows the operation of the reactor output control apparatus of Example 1 and the state in a boiling water reactor.

Hereinafter, in the embodiment of the present invention, when a reactor shutdown function loss event occurs in a boiling water reactor (BWR) in which the coolant is circulated by the coolant recirculation system piping and the recirculation pump, the recirculation pump The state of shifting to the low core flow rate state due to the stoppage of the reactor will be described as an example.

First, the schematic configuration of each device related to the output control device of the boiling water reactor according to the embodiment of the present invention and the circuit arrangement relationship thereof will be described with reference to FIG. FIG. 1 shows an overall schematic configuration diagram and a circuit diagram of a boiling water reactor according to an embodiment of the present invention.

As shown in FIG. 1, in a boiling water reactor, a reactor pressure vessel 1 is housed in a reactor storage vessel 30, and a shroud 7 surrounding the core 8 and the core 8 is contained in the reactor pressure vessel 1. , A jet pump 6 arranged around the shroud 7, an air-water separator placed on the top lid of the shroud 7 (not shown), and a steam dryer placed above the air-water separator (not shown). Is housed.

A plurality of fuel assemblies (not shown) are loaded in the core 8, and the lower end of each fuel assembly is supported by the core support plate and the upper end is held by the upper grid plate. Here, the fuel assembly has a fuel rod in which a plurality of pellets of uranium fuel, for example, as a nuclear fuel material are filled in a stainless steel cladding tube in the axial direction thereof. A fuel assembly is formed by arranging a plurality of fuel rods in a square grid in a channel box having a square cross section.

As shown in FIG. 1, at the lower part of the reactor containment vessel 30, control rods (not shown) inserted between a plurality of fuel assemblies loaded in the core 8 in the reactor pressure vessel 1 from below are It is arranged. In FIG. 1, for convenience of illustration, the control rod drive mechanism and the control rod guide tube for inserting and removing these plurality of control rods into or from the core 8 are omitted.

The control rods have a substantially cross-shaped cross section and are inserted through a predetermined interval (water gap) of four fuel assemblies loaded on the core 8, that is, four fuel assemblies adjacent to each other. Will be done. A unit cell is composed of four fuel assemblies arranged so that the two sides of the channel box face each other and one control rod on a control rod having a substantially cross-shaped cross section.

Among the above unit cells, the control rods arranged in the unit cell functioning as the control cell are inserted into and removed from the core 8 in order to adjust the output of the boiling water reactor. Further, a plurality of control rods arranged other than the control cell are rarely inserted into the core 8 when the boiling water reactor is stopped in an emergency for some reason (Scrum).

The steam separator is arranged above the upper grid plate (not shown) located at the upper end of the core 8.

Further, in the reactor pressure vessel 1, the gas-liquid two-phase steam generated by the nuclear split reaction of the core 8 is transferred to a turbine (not shown) installed in the turbine building via a steam separator and a steam dryer. A main steam pipe (not shown) for introducing dried steam is provided. Further, the steam used to drive the turbine is condensed into a cooling material which is a liquid phase via a condenser (not shown), and then a water supply system pipe (not shown) is installed in the reactor pressure vessel 1 again. Introduced through.

The jet pump 6 is a pump for obtaining a recirculation flow of the coolant required for cooling the core 8 in the reactor pressure vessel 1.

Further, the reactor containment vessel 30 has a dry well and a pressure suppression chamber (not shown) in which a suppression pool 31 filled with a coolant such as water is formed inside. The dry well in the reactor containment vessel 30 and the suppression pool 31 in the pressure suppression chamber are communicated with each other via a vent passage.

Further, in the reactor storage vessel 30, a cooling material such as water introduced to the outside of the shroud 7 in the reactor pressure vessel 1 is once passed to the outside of the reactor pressure vessel 1 via the water supply system piping. A recirculation pump 3 and a coolant recirculation system pipe 2 for recirculating the inside of the shroud 7 in the reactor pressure vessel 1 are provided.

Although the recirculation pump 3 is extremely rare, in the unlikely event that a control rod insertion failure (scrum failure event: ATWS event) occurs, the recirculation pump 3 is automatically tripped (the recirculation pump 3 is urgently stopped).

The cooling material recirculation system pipe 2 is a pipe that connects the recirculation pump 3 and the reactor pressure vessel 1, and is provided with an inlet valve 4 on the upstream side of the recirculation pump 3 and an outlet valve 5 on the downstream side. There is.

Further, the reactor pressure vessel 1 is provided with a coolant water level gauge 1A for measuring the coolant water level and a coolant flow meter 1B for measuring the coolant flow rate.

In FIG. 1, the coolant recirculation system pipe 2 is shown by a solid line, the signal line is shown by a dotted line arrow, and the control signal is shown by a broken line.

Further, although it is extremely rare, in order to inject boric acid water into the reactor pressure vessel 1 in the unlikely event that the control rod insertion failure occurs, the reactor pressure vessel 1 is used as a boric acid water injection system (SLC). Inside the reactor pressure vessel 1 from the boric acid water injection nozzle 11 arranged near the bottom of the reactor, the boric acid water storage tank 9 for storing boric acid water, and the boric acid water injection nozzle 11 from the boric acid water storage tank 9. Is provided with a boric acid water injection pump 10 for injecting boric acid water into the reactor.

Of these, the boric acid water injection nozzle 11 is attached to the reactor pressure vessel 1 so as to inject boric acid water from the lower side of the reactor pressure vessel 1.

The boric acid water storage tank 9 has a boric acid water level gauge 9A for measuring the water level of boric acid water stored inside, and the boric acid water injection nozzle 11 has a flow rate of boric acid water flowing inside the boric acid water injection nozzle 11. A flow meter 11A for measuring the above is provided.

Next, the reactor output control device in the boiling water reactor of this embodiment will be described.

The reactor output control device in this embodiment is composed of a control device 18 for controlling the start / stop of the recirculation pump 3 and / or the discharge pressure of the pump as shown in FIG.

The control device 18 is composed of, for example, a processor such as a CPU, a ROM for storing various programs, a RAM for storing data in the middle of calculation or a calculation result, or a storage device such as an HDD (not shown). In the above-mentioned various programs, a program for transmitting a start / stop command of the recirculation pump 3 or an operation pattern of the recirculation pump 3 stored in advance in the storage device is read out, and the discharge pressure of the pump is obtained. Programs etc. are included.

The control device 18 is installed at a desired position in the reactor building where the reactor containment vessel 30 is installed, or at a desired position outside the reactor building. When it is installed outdoors in the reactor building, the control device 18 may be provided with a wireless communication function, and the recirculation pump 3 may be provided with at least a wireless reception function.

In the control device 18 of this embodiment, the recirculation pump 3 is stopped at the AND gate 17A, the cooling material water level in the reactor is lower than the preset value, and the borate water is in the reactor pressure vessel 1. The recirculation pump start signal 17 for starting the recirculation pump 3 is output to the recirculation pump 3 on condition that the water is injected into the recirculation pump 3.

Hereinafter, the configuration for determining each condition will be described with reference to FIG.

The control device 18 is provided with an AND gate 17A that receives an input of the recirculation pump trip signal 15 output from the recirculation pump 3, and when the recirculation pump trip signal 15 is input, the recirculation pump 3 is provided. Is determined to have stopped.

Alternatively, the control device 18 receives the input of the measurement result of the coolant flow rate from the coolant flow meter 1B, and when the coolant flow rate in the reactor pressure vessel 1 falls below a preset value, the recirculation pump 3 Is determined to have stopped, and the recirculation pump trip signal 15 can be output to the AND gate 17A.

Further, the control device 18 includes a comparator 16A for determining whether or not the coolant water level in the reactor has fallen below a preset value. The comparator 16A compares the coolant water level measured by the coolant water level gauge 1A with the reactor water level set value, and when it is determined that the coolant water level is lower than the preset value, the reactor water level drop signal. 16 is output to the AND gate 17A.

The control device 18 is further configured to determine that boric acid water has been injected into the reactor pressure vessel 1, such as a boric acid water injection pump start signal output device 19, an operation mode selection switch 12, and an AND gate 20. , Has a delay timer 13.

The boric acid water injection pump start signal output device 19 determines whether or not the boric acid water injection pump 10 has started, and if it is determined that the boric acid water injection pump 10 has started, outputs a start signal to the AND gate 20.

Alternatively, in the boric acid water injection pump start signal output device 19, when the flow rate of boric acid water flowing through the boric acid water injection nozzle 11 measured by the flow meter 11A exceeds a preset value, the boric acid water is discharged into the reactor. Assuming that it is injected into the pressure vessel 1, a start signal may be output to the AND gate 20.

Alternatively, the boric acid water injection pump start signal output device 19 is used when the water level of the boric acid water stored in the boric acid water storage tank 9 measured by the boric acid water level gauge 9A falls below a preset value. It is possible to determine that the boric acid water has been injected into the reactor pressure vessel 1 and output a start signal to the AND gate 20.

The operation mode selection switch 12 is a circuit for preventing the recirculation pump 3 from being started when the boric acid water injection pump 10 is being tested. For example, in the normal mode, the operation mode selection switch 12 is for the AND gate 20. A signal indicating that the mode is not in the test mode is output, and in the case of the test mode, a test mode signal is output.

When the AND gate 20 receives a start signal from the boric acid water injection pump start signal output device 19 and a signal input from the operation mode selection switch 12 indicating that the current mode is not in the test mode, the boric acid water is atomized. It is determined that the reactor pressure vessel 1 has been injected, and the boric acid water reactor arrival signal 14 is output to the AND gate 17A.

The delay timer 13 is a part for temporarily delaying the boric acid water reactor arrival signal 14 output from the AND gate 20 to the AND gate 17A and outputting the boric acid water injection pump 10. It is determined that boric acid water has been injected into the reactor pressure vessel 1 after a predetermined time has elapsed from the start of the reactor.

Further, in the control device 18, if the output of the reactor falls below a preset value after the recirculation pump 3 is started by the above determination, the recirculation pump 3 is stopped.

Alternatively, if the control device 18 determines that the time required for all the boric acid water stored in the boric acid water storage tank 9 to be injected into the reactor pressure vessel 1 has elapsed, the recirculation pump 3 can be stopped.

Next, the operation of the reactor output control device of the first embodiment according to the present embodiment will be described with reference to FIG. FIG. 2 is an operation flow diagram of the core cooling system of the boiling water reactor of this embodiment.

Although extremely rare, when a scram failure event occurs for some reason, the pressure inside the reactor pressure vessel 1 rises, or the water level of the coolant in the reactor pressure vessel 1 drops. Therefore, the recirculation pump 3 is tripped. As a result, the flow rate of the coolant (which also functions as a neutron moderator) flowing through the core 8 decreases, but the head difference between the inside and outside of the shroud 7 in the reactor pressure vessel 1 and the upward movement due to steam generation from the core 8. The two-phase flow flow of the above causes the coolant to circulate in a natural circulation state (step S101).

After that, in order for the control device 18 to determine that the core flow rate has shifted to the natural circulation state, the process is divided into three.

First, in order to confirm whether or not the recirculation pump 3 is reliably stopped, the AND gate 17A of the control device 18 determines whether or not the recirculation pump trip signal 15 is input. (Step S102). If it is determined that the recirculation pump trip signal 15 has not been input, the process is returned as it is, and the input of the recirculation pump trip signal 15 is awaited. On the other hand, when it is determined that the recirculation pump trip signal 15 has been input, the process proceeds to step S106.

In this step S102, as an alternative to the determination using the recirculation pump trip signal 15, whether or not the speed of the recirculation pump 3 is lower than the preset value, and the measured value of the core flow rate is lower than the preset value. You may make a judgment as to whether or not it is.

Further, since the core flow rate in the natural circulation state decreases when the reactor water level drops, the second is that the comparator 16A of the control device 18 determines whether or not the reactor water level is below the set value (step). S103). If it is determined that the reactor water level is not below the set value, the treatment is returned as it is, and it is continuously determined whether or not the reactor water level has dropped. On the other hand, when it is determined that the reactor water level is below the set value, the reactor water level drop signal 16 is output to the AND gate 17A, and the process proceeds to step S106.

Further, in the above state, the boric acid water injection pump 10 is activated by the manual operation of the operator or the like (step S104), and the boric acid water in the boric acid water storage tank 9 passes through the boric acid water injection nozzle 11. Is injected into the reactor pressure vessel 1.

Next, the AND gate 20 and the delay timer 13 of the control device 18 determine whether or not the boric acid water has reached the reactor pressure vessel (step S105).

Here, if the recirculation pump 3 is started immediately after the boric acid water injection pump 10 is started, the core flow rate increases before the boric acid water is injected into the reactor pressure vessel 1, so that the reactor output fluctuates greatly. There is a possibility of becoming. Therefore, a delay timer 13 is installed in the control device 18 in consideration of the time required for the boric acid water to reach the reactor pressure vessel 1 after the boric acid water injection pump 10 is started, and the output fluctuation is suppressed. It is desirable to do.

Therefore, using the delay timer 13, it is determined whether or not the time set in the delay timer 13 has elapsed after the boric acid water injection pump 10 is started. When it is determined that the predetermined time has elapsed, the delay timer 13 outputs the boric acid water reactor arrival signal 14 to the AND gate 17A. On the other hand, when it is determined that the predetermined time has not elapsed, the process is returned and the predetermined time elapses.

At this time, the transmission condition of the boric acid water reactor arrival signal 14 is that the measured value of the flow rate of the boric acid water injection nozzle 11 exceeds the preset value, or the water level of the boric acid water storage tank 9 is a preset value. It is also possible to go below.

When the boric acid water reactor arrival signal 14, the recirculation pump trip signal 15, and the reactor water level drop signal 16 are all input, the AND gate 17A of the control device 18 starts the recirculation pump with respect to the recirculation pump 3. A signal 17 is transmitted to start the recirculation pump 3 (step S106).

After that, the recirculation pump 3 is started by the start instruction of the control device 18 in step S106 (step S107). As a result, the flow rate of the coolant in the core 8 increases (step S108). Note that FIG. 2 shows an example in which the control device 18 instructs the recirculation pump 3 located on the side closer to the boric acid water injection nozzle 11 of the two recirculation pumps 3 to start, but on the opposite side. Only the recirculation pump 3 of the above may be started, or two recirculation pumps 3 may be started.

By starting the recirculation pump 3 in step S107, the core flow rate increases, the circulation force from the lower part to the upper part of the core 8 increases, and the core 8 of boron contained in the boric acid water injected into the reactor pressure vessel 1 increases. Inward mixing is promoted (step S109).

By promoting the mixing of boron, the neutrons in the core 8 are easily absorbed by boron, so that the fission reaction is suppressed and the state shifts to a subcritical state (step S110).

After that, the control device 18 determines whether or not the output of the reactor is equal to or less than the set value due to the transition to the subcritical state (step S111). If the output is not less than or equal to the set value, the process returns to step S111 and waits until the output further decreases. On the other hand, when it is determined that the output is equal to or less than the set value, the process proceeds to step S112, and the stop signal of the recirculation pump 3 is output to the recirculation pump 3 (step S112).

In this step S112, instead of determining whether or not the output of the reactor is equal to or lower than the set value, all the boric acid water stored in the boric acid water storage tank 9 is injected into the reactor pressure vessel 1. The recirculation pump 3 may be stopped when the time required for the reactor has elapsed.

Next, the effect of this embodiment will be described.

In the boiling water reactor of the present embodiment described above, the boric acid water in the boric acid water storage tank 9 is injected into the reactor pressure vessel 1, the boric acid water storage tank 9, and the reactor pressure vessel 1. A water injection nozzle 11, a boric acid water injection pump 10 that sends boric acid water to the reactor pressure vessel 1 via the boric acid water injection nozzle 11, and a recirculation pump 3 that circulates the cooling material in the reactor pressure vessel 1. And, it is equipped with. Further, the control device 18 indicates that the recirculation pump 3 is stopped, the coolant water level in the reactor is below a preset value, and boric acid water is injected into the reactor pressure vessel 1. As a condition, the recirculation pump 3 is started.

With such a configuration, it becomes possible to provide a control device 18 capable of effectively mixing boron contained in boric acid water injected into the reactor pressure vessel 1. For example, the mixing of boron contained in the boric acid water injected into the reactor pressure vessel 1 is promoted, and more neutrons are more easily absorbed by boron in the core, so that the application of negative reactivity is effective. This makes it possible to efficiently shift to the subcritical state in a short time.

Further, the control device 18 determines that the borate water has been injected into the reactor pressure vessel 1 when the borate water injection pump 10 is started, or the flow rate of the borate water in the borate water injection nozzle 11 is predetermined. When it is determined that boric acid water has been injected into the reactor pressure vessel 1 when it exceeds the set value, or when the water level of boric acid water stored in the boric acid water storage tank 9 falls below the preset value. By determining that the borate water has been injected into the reactor pressure vessel 1, it is possible to directly or indirectly detect the start of the borate water injection pump 10 with certainty.

Further, the control device 18 determines that the boric acid water has been injected into the reactor pressure vessel 1 after a predetermined time has elapsed from the start of the boric acid water injection pump 10, so that the boric acid water is injected into the reactor pressure vessel 1. It is possible to effectively suppress the activation of the recirculation pump 3 before it is injected into the reactor 1, and it is possible to more reliably suppress the fluctuation of the reactor output.

Further, the control device 18 does not start the recirculation pump 3 when the boric acid water injection pump 10 is in the test, thereby reliably preventing the recirculation pump 3 from starting at an inappropriate timing. can do.

Further, when the trip signal of the recirculation pump 3 is input, the control device 18 determines that the recirculation pump 3 has stopped, or sets a preset value for the flow rate of the cooling material in the reactor pressure vessel 1. If it falls below the limit, it is determined that the recirculation pump 3 has stopped, so that the stop of the recirculation pump 3 can be detected directly or indirectly.

Further, when the output of the boiling water reactor falls below a preset value, the control device 18 stops the recirculation pump 3 or all the boric acid water stored in the boric acid water storage tank 9 is atomic. By stopping the recirculation pump 3 after the time required for injection into the reactor pressure vessel 1 has elapsed, it is possible to prevent the recirculation pump 3 from continuing to be driven more than necessary.

Further, when the boric acid water injection nozzle 11 is attached to the reactor pressure vessel 1 so as to inject boric acid water from the lower side of the reactor pressure vessel 1, boron is likely to settle in the lower part of the core 8. Therefore, the control device 18 of the present invention can effectively mix boron even in such a system.

<Others>
The present invention is not limited to the above embodiment, and various modifications and applications are possible. The above-mentioned examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations.

1 ... Reactor pressure vessel 1A ... Cooling material water level gauge 1B ... Cooling material flow meter 2 ... Cooling material recirculation system piping 3 ... Recirculation pump 4 ... Inlet valve 5 ... Outlet valve 6 ... Jet pump 7 ... Shroud 8 ... Core 9 ... borate water storage tank 9A ... borate water level meter 10 ... borate water injection pump 11 ... borate water injection nozzle 11A ... flow meter 12 ... operation mode selection switch 13 ... delay timer 14 ... borate water reactor arrival signal 15 ... Recirculation pump trip signal 16 ... Reactor water level drop signal 16A ... Comparer 17 ... Recirculation pump start signal 17A ... AND gate 18 ... Control device 19 ... Borate water injection pump start signal output device 20 ... AND gate 30 ... Reactor storage container 31 ... Suppression pool

Claims (9)

It is a reactor output control device in a boiling water reactor.
The boiling water reactor includes a reactor pressure vessel, a boric acid water storage tank, a boric acid water injection nozzle for injecting boric acid water in the boric acid water storage tank into the reactor pressure vessel, and the hoe. A boric acid water injection pump that sends the boric acid water to the reactor pressure vessel via an acid water injection nozzle and a recirculation pump that circulates the cooling material in the reactor pressure vessel are provided.
The reactor output control device is
The recirculation pump is stopped, the coolant water level in the reactor is lower than a preset value, and the boric acid water is injected into the reactor pressure vessel. Start the circulation pump ,
When the output of the boiling water reactor falls below a preset value, or the time required for all the boric acid water stored in the boric acid water storage tank to be injected into the reactor pressure vessel. A reactor power control device characterized in that the recirculation pump is stopped after a lapse of time . In the reactor output control device according to claim 1,
The reactor output control device is characterized in that, when the boric acid water injection pump is started, it is determined that the boric acid water has been injected into the reactor pressure vessel. In the reactor output control device according to claim 2,
The reactor output control device determines that the boric acid water has been injected into the reactor pressure vessel when the flow rate of the boric acid water in the boric acid water injection nozzle exceeds a preset value. Reactor output control device as a feature. In the reactor output control device according to claim 2,
The reactor output control device determines that the boric acid water has been injected into the reactor pressure vessel when the water level of the boric acid water stored in the boric acid water storage tank falls below a preset value. Reactor power control device characterized by In the reactor output control device according to claim 2,
The reactor output control device is characterized in that it determines that the boric acid water has been injected into the reactor pressure vessel after a predetermined time has elapsed from the start of the boric acid water injection pump. Device. In the reactor output control device according to claim 2,
The reactor output control device is a reactor output control device, characterized in that the recirculation pump is not started when the boric acid water injection pump is being tested. In the reactor output control device according to claim 1,
The reactor output control device is characterized in that, when a trip signal of the recirculation pump is input, the reactor output control device determines that the recirculation pump has stopped. In the reactor output control device according to claim 1,
The reactor output control device is characterized in that it determines that the recirculation pump has stopped when the flow rate of the coolant in the reactor pressure vessel falls below a preset value. .. In the reactor output control device according to claim 1,
The reactor output control device is characterized in that the boric acid water injection nozzle is attached to the reactor pressure vessel so as to inject the boric acid water from the lower side of the reactor pressure vessel.

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