JP6951299B2 - Water pressure control unit - Google Patents

Description

The present invention relates to a water pressure control unit, and more particularly to a water pressure control unit of a control rod drive mechanism which is a component of a boiling water nuclear power plant.

Generally, a control rod drive mechanism is a device that drives a control rod for controlling the output of a nuclear reactor, and a hydraulic control unit is a device that receives an electric signal and supplies a driving force by hydraulic pressure to the control rod drive mechanism. ..

For example, the output of a boiling water reactor is controlled not only by controlling the coolant, but also by inserting or pulling out the control rods in the control rod drive mechanism. In addition, at the time of emergency shutdown of the nuclear reactor, high-pressure water is supplied from the hydraulic control unit to the control rod drive mechanism, so that the control rods arranged above the control rod drive mechanism are placed between the fuel assemblies using the hydraulic pressure as the drive source. Make an emergency insertion (hereinafter referred to as "scram") and shut down the reactor.

The hydraulic control unit includes a scrum valve for performing scrum operation. The scrum valve closes when air pressure is applied by, for example, an air supply system called an instrumentation air supply system, and opens when the air applying this air pressure is discharged and the air pressure is lost. In the event of an emergency shutdown of a nuclear reactor (reactor emergency), a scram signal from the central control room of a nuclear power plant immediately opens the scram valve, and the hydraulic control unit supplies high-pressure water to the control rod drive mechanism. Scram operation is performed by water. The opening and closing of the scrum valve is controlled by the scrum pilot valve. The scrum pilot valve opens the scrum valve by shutting off the supply of air from the instrumentation air supply system to the scrum valve and discharging the air that closes the scrum valve immediately after receiving the scrum signal.

An example of a conventional hydraulic control unit in a boiling water reactor is described in Patent Document 1.

In addition, the reactor is provided with a retrofit emergency stop valve in the instrumentation air supply system in case the scrum pilot valve does not operate normally. The emergency stop valve is opened after a predetermined time has passed after receiving the scrum signal from the central control room, and the water pressure control unit is opened by discharging the air that gives air pressure to the scrum valve and opening the scrum valve. Supply high-pressure water to the control rod drive mechanism.

Further, the reactor is provided with an alternative control rod insertion valve opened in the instrumentation air supply system by an alternative control rod insertion signal which is a signal of a system different from the scrum signal. The alternative control rod insertion valve is opened by the alternative control rod insertion signal from the central control room in the event of a reactor emergency, exhausts the air that gives air pressure to the scrum valve, opens the scram valve, and the control rod drive mechanism from the hydraulic control unit. Supply high pressure water to.

The hydraulic control unit can supply high-pressure water to the control rod drive mechanism by a plurality of types of valves such as a scrum valve, a rear-end emergency stop valve, and an alternative control rod insertion valve, and has multiplicity for supplying high-pressure water. In addition, the water pressure control unit has independence in supplying high-pressure water by opening different valves to supply high-pressure water to the control rod drive mechanism by independent signals in which the systems of the scrum signal and the alternative control rod insertion signal are different from each other. .. The scrum operation of the control rod drive mechanism using the hydraulic control unit is thus enhanced in reliability.

Japanese Unexamined Patent Publication No. 5-60890

A hydraulic control unit including a scrum valve is provided with a scrum pilot valve that controls the opening and closing of the scrum valve upstream of the scrum valve in the air supply path to the scrum valve. Since the scrum pilot valve takes in air including foreign matter mixed during inspection, foreign matter may adhere to the inside of the valve body and cause malfunction (including malfunction) in the valve body. Furthermore, when the scrum pilot valve malfunctions, the supply of air at the instrumentation air supply port (inlet of air supplied from the instrumentation air supply system) of the scrum pilot valve is stopped and the instrumentation air is exhausted. The exhaust operation at the outlet (the air outlet that closes the scrum valve) may be delayed, which may adversely affect the scrum performance.

On the other hand, if the operation of the scrum valve or the scrum pilot valve is controlled by a method other than the air actuation method as described above, it is difficult to maintain the multiplicity and independence of the conventional hydraulic control unit.

Further, in order to improve the reliability of the control rod drive mechanism, it is necessary to prevent the control rod drive mechanism from being driven due to the malfunction of the scrum pilot valve, that is, the control rod drive mechanism from malfunctioning.

An object of the present invention is to provide a water pressure control unit capable of maintaining multiplicity and independence of high pressure water supply and preventing malfunction.

The hydraulic control unit according to the present invention has a first pipe connected to a control rod drive mechanism for driving a control rod of a nuclear reactor, a sluice valve provided in the first pipe, and high-pressure water in the control rod drive mechanism. The accumulator for supplying the above accumulator, the second pipe connected to the accumulator, the first solenoid valve, the second solenoid valve, and the blast valve are provided. The first solenoid valve, the second solenoid valve, and the blast valve are connected to the first pipe and the second pipe, and are provided in parallel between the sluice valve and the accumulator. It is configured to supply the high-pressure water to the control rod drive mechanism when opened.

According to the present invention, it is possible to provide a water pressure control unit capable of maintaining the multiplicity and independence of the supply of high-pressure water and preventing malfunction.

System diagram of the conventional hydraulic control unit. The system diagram of the water pressure control unit according to Example 1 of this invention. The system diagram of the water pressure control unit according to Example 4 of this invention. The system diagram of the water pressure control unit according to Example 5 of this invention. The external view of the water pressure control unit according to Example 1 of this invention. The cross-sectional view which shows the outline of the solenoid valve A and the solenoid valve B. Sectional drawing which shows the outline of the blast valve. The system diagram of the water pressure control unit according to Example 6 of this invention.

The hydraulic control unit is connected to the control rod drive mechanism that drives the control rods of the nuclear reactor by a pipe, and supplies high-pressure water to the control rod drive mechanism to give a driving force to the control rod drive mechanism. High-pressure water is pressurized water (pressurized water).

The water pressure control unit according to the present invention includes a solenoid valve and a blast valve as an alternative to the air-operated valve provided in the conventional water pressure control unit, and includes a scrum valve, a scrum pilot valve, and an instrumented air supply provided in the conventional water pressure control unit. No system is required. In the water pressure control unit according to the present invention, by supplying high-pressure water to the control rod drive mechanism using a solenoid valve and a blast valve, the multiplicity and independence of high-pressure water supply are maintained as in the conventional water pressure control unit. In addition to being able to prevent malfunctions caused by pneumatically operated valves. In addition, since the instrumentation air supply system including the alternative control rod insertion valve and the emergency stop valve is not required, the system can be simplified.

Hereinafter, the water pressure control unit according to the embodiment of the present invention will be described with reference to the drawings. In the following examples, the same elements may be designated by the same reference numerals, and repeated description of these elements may be omitted.

First, a conventional hydraulic control unit will be described.

FIG. 1 is a system diagram of a conventional water pressure control unit 100. The conventional water pressure control unit 100 includes a plurality of pipes 12, 12A, 12B, 12C connecting each component of the water pressure control unit 100, a scram valve 5, an instrumentation air supply system 2, a scram pilot valve 6, and the like. It includes an alternative control rod insertion valve 4, a rear-end emergency stop valve 3, a plurality of sluice valves 7, 7B, a purge water solenoid valve 11, an accumulator 8, a nitrogen container 9, and an instrumentation block 10. The water pressure control unit 100 supplies the control rod drive mechanism 13 with high-pressure water to insert the control rods 14 between the fuel assemblies. The accumulator 8 is a device for supplying high-pressure water to the control rod drive mechanism 13.

The scrum valve 5 is an air-operated valve provided in the pipes 12B and 12C connecting the control rod drive mechanism 13 and the accumulator 8 to perform the scrum operation. The instrumentation air supply system 2 is connected to the scrum pilot valve 6 by the instrumentation air supply system pipe 12A, air is supplied to the scrum valve 5 via the scrum pilot valve 6, and the scrum valve 5 is closed by this air pressure. The scrum pilot valve 6 is provided in the instrumentation air supply system pipe 12A connected to the scrum valve 5, is located upstream of the scrum valve 5 in the air supply path to the scrum valve 5, and opens and closes the scrum valve 5. Control. The scrum pilot valve 6 includes an instrumentation air supply port that is an inlet for air supplied from the instrumentation air supply system 2 and an instrumentation air outlet that is an air discharge port that closes the scrum valve 5.

The instrumentation air supply system 2 includes an alternative control rod insertion valve 4 and an emergency stop valve 3. The alternative control rod insertion valve 4 is connected to the scrum pilot valve 6 by an instrumentation air supply system pipe 12A. The instrumentation air supply system piping 12A is provided with an instrumentation air supply system sluice valve 7A. The emergency stop valve 3 is connected to the alternative control rod insertion valve 4 and is connected to the scrum pilot valve 6 via the alternative control rod insertion valve 4. The emergency stop valve 3 is located upstream of the alternative control rod insertion valve 4 in the air supply path to the scrum valve 5.

The plurality of sluice valves 7 and 7B are provided in the pipes 12 and 12B. The purge water solenoid valve 11 is provided in the pipe 12 connected to the control rod drive mechanism 13. The accumulator 8 includes a movable piston 8A inside, is connected to the scrum valve 5 by a pipe 12C, and supplies high-pressure water to the scrum valve 5. The nitrogen container 9 is provided at one end of the accumulator 8. The instrumentation block 10 is provided between the accumulator 8 and the nitrogen container 9. The pipes 12C and 12B connecting the accumulator 8 and the control rod drive mechanism 13 have a sluice valve 7B upstream of the control rod drive mechanism 13 (pipe 12B) in the flow of high-pressure water from the accumulator 8 to the control rod drive mechanism 13. Is provided.

During normal operation of the reactor, the scrum pilot valve 6 is supplied with air to the scrum valve 5 because the instrumentation air supply port is open and the instrumentation air discharge port is closed. Therefore, the scrum valve 5 is closed, and the high-pressure water from the accumulator 8 does not flow to the control rod drive mechanism 13 by the scrum valve 5.

At the time of emergency shutdown of the reactor (reactor emergency), the scrum pilot valve 6 immediately closes the instrumentation air supply port and opens the instrumentation air discharge port immediately after receiving the scrum signal from the main control room, and the scrum. The air supplied to the valve 5 is discharged. When the scrum valve 5 is immediately opened by this air discharge, the high-pressure water from the accumulator 8 is supplied to the control rod drive mechanism 13, and the control rod 14 is inserted between the fuel assemblies.

At this time, in case the scrum pilot valve 6 does not operate normally due to a failure or the like, the rear-end emergency stop valve 3 opens after a predetermined time has elapsed after receiving the scrum signal from the main control room. When the emergency stop valve 3 is opened, the air supplied to the scrum valve 5 and the scrum pilot valve 6 (the air that gives air pressure to the scrum valve 5) is discharged, the scrum valve 5 is opened, and the water pressure control unit 100 High-pressure water is supplied to the control rod drive mechanism 13.

Further, the alternative control rod insertion valve 4 is opened by an alternative control rod insertion signal from the central control room in the event of a reactor emergency. When the alternative control rod insertion valve 4 is opened, the air giving air pressure to the scrum valve 5 is discharged, the scrum valve 5 is opened, and high-pressure water is supplied from the water pressure control unit 100 to the control rod drive mechanism 13. The alternative control rod insertion signal for operating the alternative control rod insertion valve 4 is an independent signal transmitted by a system different from the scrum signal for operating the scrum pilot valve 6 and the emergency stop valve 3.

As described above, the conventional hydraulic control unit 100 can supply high-pressure water to the control rod drive mechanism 13 by three different types of valves: a scrum valve 5, a rear-end emergency stop valve 3, and an alternative control rod insertion valve 4. , With multiplicity for high pressure water supply. Further, different valves can be opened by independent signals in which the systems of the scrum signal and the alternative control rod insertion signal are different from each other to supply high-pressure water to the control rod drive mechanism 13, and the supply of high-pressure water is independent.

Hereinafter, the water pressure control unit according to the first embodiment of the present invention will be described. In the following description, the water pressure control unit according to the present embodiment will be mainly described in that it differs from the conventional water pressure control unit 100.

FIG. 2 is a system diagram of the water pressure control unit 1 according to the present embodiment. FIG. 4 is an external view of the water pressure control unit 1 according to the present embodiment. As shown in FIG. 4, the nitrogen container 9 is supported by the frame 21.

The water pressure control unit 1 according to the present embodiment includes a pipe 12B connected to the control rod drive mechanism 13, a sluice valve 7B provided in the pipe 12B, and a pipe 12C connected to the accumulator 8.

Unlike the conventional water pressure control unit 100, the water pressure control unit 1 according to the present embodiment includes a scrum valve 5, a scrum pilot valve 6, a rear-end emergency stop valve 3, an alternative control rod insertion valve 4, and an instrumentation air supply system 2. However, as a valve having a function corresponding to the function of these valves, a solenoid valve A15, a solenoid valve B16, and a blast valve 17 are provided. The solenoid valve A15, the solenoid valve B16, and the blast valve 17 are valves that control the flow of high-pressure water from the accumulator 8 to the control rod drive mechanism 13, and when closed, supply the control rod drive mechanism 13 with high-pressure water. When opened, high-pressure water is supplied to the control rod drive mechanism 13.

The solenoid valve A15, the solenoid valve B16, and the blast valve 17 are connected to the pipe 12B connected to the control rod drive mechanism 13 and the pipe 12C connected to the accumulator 8, and the sluice valve 7B and the accumulator provided in the pipe 12B are connected. 8 and 8 are provided in parallel with each other by piping. That is, the solenoid valve A15, the solenoid valve B16, and the blast valve 17 are arranged in parallel with each other between the accumulator 8 and the control rod drive mechanism 13.

The pipe 12C connected to the accumulator 8 includes a branch portion 19 in which the pipe 12C branches into three. The pipe 12B connected to the sluice valve 7B includes a flow path box 20 in which the three pipes merge with each other. One of the three pipes branched at the branch portion 19 is connected to each of the solenoid valve A15, the solenoid valve B16, and the blast valve 17, and high-pressure water flows in from the accumulator 8. Further, pipes for discharging high-pressure water are connected to each of the solenoid valve A15, the solenoid valve B16, and the blast valve 17. These pipes merge with each other at the flow path box 20. The high-pressure water discharged from each of the solenoid valve A15, the solenoid valve B16, and the blast valve 17 flows to the control rod drive mechanism 13 through the flow path box 20, the pipe 12B, and the sluice valve 7B.

FIG. 5 is a cross-sectional view showing an outline of the solenoid valve A15 and the solenoid valve B16. Each of the solenoid valve A15 and the solenoid valve B16 is provided with two solenoids for controlling the opening and closing of the valves, and is a solenoid valve in which two solenoids are operated. The solenoid valve A15 includes two solenoids 24a, a piston 25a, and two springs 22a and 23a. The solenoid valve B16 includes two solenoids 24b, a piston 25b, and two springs 22b and 23b. The solenoid valve B16 includes a fluid supply port 26 in which high-pressure water supplied from the accumulator 8 flows into the solenoid valve B16. The high-pressure water that has flowed into the solenoid valve B16 from the fluid supply port 26 also flows into the solenoid valve A15. The piston 25a and the piston 25b are provided with a flow path hole 28a and a flow path hole 28b for flowing high-pressure water from the fluid supply port 26, respectively. The solenoid valve A15 and the solenoid valve B16 are provided with a fluid discharge port 27a and a fluid discharge port 27b for discharging high-pressure water that has passed through the flow path hole 28a and the flow path hole 28b from the solenoid valve A15 and the solenoid valve B16, respectively.

When the two solenoids 24a and 24b are excited, the solenoid valve A15 and the solenoid valve B16 attract the pistons 25a and 25b against the elastic forces of the springs 22a, 23a and the springs 22b, 23b, respectively. .. In this state, the positions of the flow path hole 28a and the flow path hole 28b and the positions of the fluid discharge port 27a and the fluid discharge port 27b are different from each other, so that the flow path of the high-pressure water from the accumulator 8 is closed. That is, the solenoid valve A15 and the solenoid valve B16 are closed, and high-pressure water is not discharged from the solenoid valve A15 and the solenoid valve B16.

When the solenoid valve A15 and the solenoid valve B16 change the two solenoids 24a and 24b from the excited state to the non-excited state, respectively, the pistons 25a and 25b have the elastic forces of the springs 22a and 23a and the springs 22b and 23b, respectively. Move by. The piston 25a and the piston 25b move, and the flow path hole 28a and the flow path hole 28b overlap with the position of the fluid discharge port 27a and the position of the fluid discharge port 27b, respectively. It is discharged from the solenoid valve B16.

FIG. 6 is a cross-sectional view showing an outline of the blast valve 17. The blast valve 17 includes a blast portion 29, a piston 30, a fluid supply port 31, and a fluid discharge port 32. Before the blast portion 29 explodes, the flow path from the fluid supply port 31 to the fluid discharge port 32 is closed by the piston 30, and the blast valve 17 is closed, so that the high-pressure water is not discharged from the blast valve 17. When the blasting portion 29 explodes and the piston 30 moves, the flow path from the fluid supply port 31 to the fluid discharge port 32 opens, and the high-pressure water supplied from the fluid supply port 31 to the blast valve 17 becomes the fluid discharge port 32. Is discharged from. That is, the blast valve 17 is opened by the explosion of the blast portion 29, and the high-pressure water is discharged from the blast valve 17.

The operations of the solenoid valve A15, the solenoid valve B16, and the blast valve 17 will be described with reference to FIG. 2 during normal operation of the reactor and during an emergency of the reactor. The solenoid valve A15 has the functions of the scrum valve 5 and the scrum pilot valve 6 in the conventional hydraulic control unit 100, and the solenoid valve B16 has the function of the emergency stop valve 3 in the conventional hydraulic control unit 100 and explodes. The valve 17 has the function of the alternative control rod insertion valve 4 in the conventional hydraulic control unit 100.

During normal operation of the reactor, the solenoid valve A15, the solenoid valve B16, and the blast valve 17 are closed. Therefore, the high-pressure water from the accumulator 8 does not flow out from the solenoid valve A15, the solenoid valve B16, and the blast valve 17, and does not flow into the control rod drive mechanism 13.

In the event of a nuclear reactor emergency, the central control room transmits a scrum signal to the solenoid valve A15 and the solenoid valve B16, and transmits an alternative control rod insertion signal to the blast valve 17. The operations of the solenoid valve A15, the solenoid valve B16, and the blast valve 17 in an emergency of a nuclear reactor are as follows.

Immediately after receiving the scram signal transmitted from the main control chamber, the solenoid valve A15 opens with the solenoid 24a in a non-excited state, discharges high-pressure water from the accumulator 8 from the solenoid valve A15, and causes the control rod drive mechanism 13 to discharge the high-pressure water. By supplying high-pressure water, the control rods 14 are inserted between the fuel assemblies.

The solenoid valve B16 opens in a non-excited state after a predetermined time has elapsed after receiving the scram signal transmitted from the main control chamber, and discharges the high-pressure water from the accumulator 8 from the solenoid valve B16. , High pressure water is supplied to the control rod drive mechanism 13. The solenoid valve B16 has the same function as the rear emergency stop valve 3 in the conventional hydraulic control unit 100, and is used to insert the control rods 14 between the fuel assemblies when the solenoid valve A15 does not operate normally. , High pressure water is supplied to the control rod drive mechanism 13.

The solenoid valve B16 opens after a predetermined time has elapsed after receiving the scrum signal. The solenoid valve A15 opens immediately after receiving the scrum signal and before the lapse of this predetermined time. This predetermined time can be predetermined.

When the blast valve 17 receives the alternative control rod insertion signal transmitted from the central control room, the blast section 29 explodes and opens, discharges the high-pressure water from the accumulator 8 from the blast valve 17, and causes the control rod drive mechanism 13 to have a high pressure. Supply water.

The alternative control rod insertion signal is a signal of a system different from the scrum signal, and is transmitted from the central control room independently of the scrum signal. For example, the alternative control rod insertion signal is transmitted from the central control chamber to the blast valve 17 separately from the scrum signal when it is detected that the reactor pressure exceeds the set pressure.

The blast valve 17 has the same function as the alternative control rod insertion valve 4 in the conventional hydraulic control unit 100, and the solenoid valve A15 and the solenoid valve B16 are opened by an independent signal having a different system from the solenoid valve A15. High-pressure water is supplied to the control rod drive mechanism 13 in order to insert the control rods 14 between the fuel assemblies when the solenoid valve B16 or the solenoid valve B16 does not operate normally.

The water pressure control unit 1 according to the present embodiment has the same functions as the scrum valve 5, the scrum pilot valve 6, the alternative control rod insertion valve 4, and the emergency stop valve 3 provided in the conventional water pressure control unit 100, and has the same functions as the conventional water pressure. Similar to the control unit 100, it is possible to maintain multiplicity and independence with respect to the supply of high-pressure water to the control rod drive mechanism 13. Since the water pressure control unit 1 according to the present embodiment does not use an air-operated valve, malfunctions caused by the air-operated valve can be prevented, and the instrumentation air supply system 2 is unnecessary, so that the system can be simplified. Can be planned.

Further, since the solenoid valve A15 and the solenoid valve B16 each include two solenoids 24a and 24b, it is possible to prevent the control rod drive mechanism 13 from malfunctioning due to opening due to a malfunction. This is because even if one solenoid 24a (or solenoid 24b) of the solenoid valve A15 (or solenoid valve B16) changes from an excited state to a non-excited state due to a malfunction, the other solenoid 24a (or solenoid 24b) is excited. If so, the solenoid valve A15 (or solenoid valve B16) does not operate. Therefore, it is possible to prevent the control rod drive mechanism 13 from being driven due to a malfunction.

The water pressure control unit 1 according to the second embodiment of the present invention will be described. In the water pressure control unit 1 according to the present embodiment, the blast valve 17 has the functions of the scram valve 5 and the scram pilot valve 6 in the conventional water pressure control unit 100, and the solenoid valve A15 is a retrofit emergency stop valve in the conventional water pressure control unit 100. The solenoid valve B16 has the function of the alternative control rod insertion valve 4 in the conventional hydraulic control unit 100. Hereinafter, the difference between the water pressure control unit 1 according to the present embodiment and the water pressure control unit 1 according to the first embodiment will be mainly described.

In the event of a nuclear reactor emergency, the central control room transmits a scrum signal to the blast valve 17 and the solenoid valve A15, and transmits an alternative control rod insertion signal to the solenoid valve B16.

Immediately after receiving the scrum signal transmitted from the main control room, the blast valve 17 explodes and opens in the blast section 29, discharges the high-pressure water from the accumulator 8 from the blast valve 17, and causes the control rod drive mechanism 13 to discharge the high-pressure water. To supply.

After receiving the scram signal transmitted from the main control chamber, the solenoid valve A15 opens the solenoid 24a in a non-excited state after a predetermined time has elapsed, and discharges high-pressure water from the accumulator 8 from the solenoid valve A15. And supply high pressure water to the control rod drive mechanism 13.

The blast valve 17 opens immediately after receiving the scrum signal and before the lapse of this predetermined time.

When the solenoid valve B16 receives the alternative control rod insertion signal transmitted from the central control chamber, the solenoid 24b opens in a non-excited state to discharge high-pressure water from the accumulator 8 from the solenoid valve B16, and the control rod drive mechanism 13 Supply high pressure water to. The alternative control rod insertion signal is transmitted from the central control chamber to the solenoid valve B16 separately from the scrum signal when it is detected that the reactor pressure exceeds the set pressure.

Similar to the water pressure control unit 1 according to the first embodiment, the water pressure control unit 1 according to the present embodiment can maintain multiplicity and independence in supplying high-pressure water to the control rod drive mechanism 13, and is an air-operated type. It is possible to prevent malfunctions caused by the valve of the above and to simplify the system.

The water pressure control unit 1 according to the third embodiment of the present invention will be described. In the water pressure control unit 1 according to the present embodiment, the solenoid valve A15 has the functions of the scram valve 5 and the scram pilot valve 6 in the conventional water pressure control unit 100, and the blast valve 17 is a rear-end emergency stop valve in the conventional water pressure control unit 100. The solenoid valve B16 has the function of the alternative control rod insertion valve 4 in the conventional hydraulic control unit 100. Hereinafter, the difference between the water pressure control unit 1 according to the present embodiment and the water pressure control unit 1 according to the first embodiment will be mainly described.

In the event of a nuclear reactor emergency, the central control room transmits a scrum signal to the solenoid valve A15 and the blast valve 17, and an alternative control rod insertion signal to the solenoid valve B16.

Immediately after receiving the scrum signal transmitted from the main control chamber, the solenoid valve A15 opens with the solenoid 24a in a non-excited state, discharges high-pressure water from the accumulator 8 from the solenoid valve A15, and causes the control rod drive mechanism 13 to discharge the high-pressure water. Supply high pressure water.

The blast valve 17 explodes and opens after a predetermined time has elapsed after receiving the scrum signal transmitted from the main control room, and the high-pressure water from the accumulator 8 is discharged from the blast valve 17. High-pressure water is supplied to the control rod drive mechanism 13.

The solenoid valve A15 opens immediately after receiving the scrum signal and before the elapse of this predetermined time.

When the solenoid valve B16 receives the alternative control rod insertion signal transmitted from the central control chamber, the solenoid 24b opens in a non-excited state to discharge high-pressure water from the accumulator 8 from the solenoid valve B16, and the control rod drive mechanism 13 Supply high pressure water to. The alternative control rod insertion signal is transmitted from the central control chamber to the solenoid valve B16 separately from the scrum signal when it is detected that the reactor pressure exceeds the set pressure.

Like the water pressure control units 1 according to the first and second embodiments, the water pressure control unit 1 according to the present embodiment can maintain multiplicity and independence with respect to the supply of high-pressure water to the control rod drive mechanism 13, and air. Malfunctions caused by actuated valves can be prevented and the system can be simplified.

The water pressure control unit 1 according to the fourth embodiment of the present invention will be described. In the hydraulic control unit 1 according to the present embodiment, the solenoid valve is a solenoid valve in which one solenoid is provided and one solenoid is operated. Hereinafter, the difference between the water pressure control unit 1 according to the present embodiment and the water pressure control unit 1 according to the first embodiment will be mainly described.

FIG. 3A is a system diagram of the water pressure control unit 1 according to this embodiment. In the water pressure control unit 1 according to the present embodiment, each of the solenoid valve A15 and the solenoid valve B16 in the first embodiment is composed of two solenoid valves 18 connected in series. That is, the water pressure control unit 1 according to the present embodiment includes two sets of two solenoid valves 18 connected in series between the sluice valve 7B provided on the pipe 12B and the accumulator 8 and the blast valve 17. Be prepared. The two sets of solenoid valves 18 and blast valves 17 are connected to the pipe 12B connected to the control rod drive mechanism 13 and the pipe 12C connected to the accumulator 8 and arranged in parallel with each other. The solenoid valve 18 is a solenoid valve that includes one solenoid and operates one solenoid.

The set consisting of the two solenoid valves 18 connected in series can prevent the control rod drive mechanism 13 from malfunctioning, as in the solenoid valve A15 and the solenoid valve B16 in the first embodiment. Even if the solenoid of one solenoid valve 18 in the set consisting of two solenoid valves 18 connected in series changes from the excited state to the non-excited state due to a malfunction, if the solenoid of the other solenoid valve 18 is excited, Even if one solenoid valve 18 opens, the other solenoid valve 18 does not open. Since these two solenoid valves 18 are connected in series, it is possible to prevent the control rod drive mechanism 13 from being driven due to a malfunction.

The water pressure control unit 1 according to the present embodiment can maintain multiplicity and independence with respect to the supply of high-pressure water to the control rod drive mechanism 13 and air as well as the water pressure control unit 1 according to the first to third embodiments. Malfunctions caused by actuated valves can be prevented and the system can be simplified.

The water pressure control unit 1 according to the fifth embodiment of the present invention will be described. Hereinafter, the difference between the water pressure control unit 1 according to the present embodiment and the water pressure control unit 1 according to the first embodiment and the fourth embodiment will be mainly described.

FIG. 3B is a system diagram of the water pressure control unit 1 according to this embodiment. In the hydraulic control unit 1 according to the present embodiment, one of the solenoid valve A15 and the solenoid valve B16 in the first embodiment (FIG. 2) is composed of two solenoid valves 18 connected in series. FIG. 3B shows an example in which the solenoid valve A15 in the first embodiment is composed of two solenoid valves 18 connected in series. This configuration is the same as the configuration in Example 4 (FIG. 3A) in which one of the two sets of the two solenoid valves 18 connected in series is replaced with the solenoid valve B16.

The water pressure control unit 1 according to the present embodiment includes a set of two solenoid valves 18 connected in series between the sluice valve 7B provided on the pipe 12B and the accumulator 8, and the solenoid valve B16 (or solenoid valve). A15) and a blast valve 17 are provided. A set of solenoid valve 18, solenoid valve B16 (or solenoid valve A15), and blast valve 17 are connected to the pipe 12B connected to the control rod drive mechanism 13 and the pipe 12C connected to the accumulator 8 in parallel with each other. Be placed. The solenoid valve 18 is a solenoid valve that includes one solenoid and operates one solenoid. The solenoid valve B16 (or solenoid valve A15) is a solenoid valve that includes two solenoids and operates two solenoids.

The water pressure control unit 1 according to the present embodiment can also obtain the same effect as the water pressure control unit 1 according to the first to fourth embodiments.

The water pressure control unit 1 according to the sixth embodiment of the present invention will be described. Hereinafter, the difference between the water pressure control unit 1 according to the present embodiment and the water pressure control unit 1 according to the first to fifth embodiments will be mainly described.

FIG. 7 is a system diagram of the water pressure control unit 1 according to the present embodiment. In the water pressure control unit 1 according to the present embodiment, at least one of the valve having the function of the retrofit emergency stop valve 3 and the valve having the function of the alternative control rod insertion valve 4 in the conventional water pressure control unit 100 is an electric motor. It is a driven electric valve 40. The valves having the functions of the scrum valve 5 and the scrum pilot valve 6 in the conventional hydraulic control unit 100 are a solenoid valve (solenoid valve A15, solenoid valve B16, or solenoid valve 18) or a blast valve 17.

FIG. 7 shows, as an example, a configuration in which the water pressure control unit 1 includes a solenoid valve A15, an electric valve 40, and a blast valve 17. In the configuration example shown in FIG. 7, the electric valve 40 has the function of the rear-end emergency stop valve 3 in the conventional hydraulic control unit 100, and the solenoid valve A15 and the blast valve 17 are the same as in the first embodiment, respectively. It has the functions of the scrum valve 5 and the scrum pilot valve 6 and the function of the alternative control rod insertion valve 4 in the water pressure control unit 100 of the above.

The valves having the functions of the scrum valve 5 and the scrum pilot valve 6 in the conventional hydraulic control unit 100 need to be opened immediately after receiving the scrum signal in the event of a reactor emergency. Therefore, this valve is composed of a solenoid valve or a blast valve 17. The valve that opens after this valve (the valve that opens after a predetermined time has elapsed after receiving the scrum signal and the valve that opens after receiving the alternative control rod insertion signal) can be composed of the motorized valve 40. It can also be composed of a solenoid valve or a blast valve 17.

Hereinafter, the difference in configuration of the water pressure control unit 1 according to the present embodiment from the water pressure control unit 1 according to the first to third embodiments will be described.

The water pressure control unit 1 according to the present embodiment includes an electric valve 40 instead of the solenoid valve B16 in the water pressure control unit 1 according to the first embodiment, and a predetermined time elapses after the electric valve 40 receives the scrum signal. Can be configured to open from. Alternatively, the water pressure control unit 1 according to the present embodiment includes an electric valve 40 instead of the blast valve 17 in the water pressure control unit 1 according to the first embodiment, and the electric valve 40 opens when receiving an alternative control rod insertion signal. Can be configured in.

Further, the water pressure control unit 1 according to the present embodiment includes an electric valve 40 instead of the solenoid valve A15 in the water pressure control unit 1 according to the second embodiment, and a predetermined time elapses after the electric valve 40 receives the scrum signal. It can be configured to open afterwards. Alternatively, the water pressure control unit 1 according to the present embodiment includes an electric valve 40 instead of the solenoid valve B16 in the water pressure control unit 1 according to the second embodiment, and the electric valve 40 opens when receiving an alternative control rod insertion signal. Can be configured in.

Further, the water pressure control unit 1 according to the present embodiment includes an electric valve 40 instead of the blast valve 17 in the water pressure control unit 1 according to the third embodiment, and a predetermined time elapses after the electric valve 40 receives the scrum signal. It can be configured to open afterwards. Alternatively, the water pressure control unit 1 according to the present embodiment includes an electric valve 40 instead of the solenoid valve B16 in the water pressure control unit 1 according to the third embodiment, and the electric valve 40 opens when receiving an alternative control rod insertion signal. Can be configured in.

As described above, the water pressure control unit 1 according to the present embodiment can be configured by using the electric valve 40. The motorized valve 40 generally takes longer to open than the solenoid valve and the blast valve 17. Therefore, the electric valve 40 is not used for the valve having the functions of the scrum valve 5 and the scrum pilot valve 6 in the conventional hydraulic control unit 100, but the valve having the function of the emergency stop valve 3 and the alternative control rod insertion valve 4 It is preferable to use it for at least one of the valves having the above functions.

The water pressure control unit 1 according to the present embodiment can also obtain the same effect as the water pressure control unit 1 according to the first to fifth embodiments.

The present invention is not limited to the above embodiment, and various modifications are possible. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to the embodiment including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to delete a part of the configurations of each embodiment and add / replace other configurations.

1 ... Water pressure control unit, 2 ... Instrumented air supply system, 3 ... Emergency stop valve, 4 ... Alternative control rod insertion valve, 5 ... Scram valve, 6 ... Scrum pilot valve, 7 ... Partition valve, 7A ... Instrumented air Supply system sluice valve, 7B ... sluice valve, 8 ... accumulator, 8A ... piston, 9 ... nitrogen container, 10 ... instrumentation block, 11 ... purged water solenoid valve, 12 ... piping, 12A ... instrumentation air supply system piping, 12B ... Piping connected to the control rod drive mechanism, 12C ... Piping connected to the accumulator, 13 ... Control rod drive mechanism, 14 ... Control rod, 15 ... Solenoid valve A, 16 ... Solenoid valve B, 17 ... Explosion valve, 18 ... Solenoid valve, 19 ... branch, 20 ... flow path box, 21 ... frame, 22a, 23a ... spring, 24a, 24b ... solenoid, 25a, 25b ... piston, 26 ... fluid supply port, 27a, 27b ... fluid discharge port, 28a, 28b ... Flow path hole, 29 ... Explosion part, 30 ... Piston, 31 ... Fluid supply port, 32 ... Fluid discharge port, 40 ... Electric valve, 100 ... Conventional hydraulic control unit.

Claims (12)

The first pipe connected to the control rod drive mechanism that drives the control rods of the reactor,
A sluice valve provided in the first pipe and
An accumulator for supplying high-pressure water to the control rod drive mechanism,
The second pipe connected to the accumulator and
The first solenoid valve and
The second solenoid valve and
Blast valve and
With
The first solenoid valve, the second solenoid valve, and the blast valve are connected to the first pipe and the second pipe, and are provided in parallel between the sluice valve and the accumulator. It is configured to supply the high-pressure water to the control rod drive mechanism when opened.
A water pressure control unit characterized by this. The first solenoid valve opens after receiving the first signal transmitted from the main control room and before a predetermined time elapses.
The second solenoid valve opens after a predetermined time has elapsed after receiving the first signal.
The blast valve opens when it receives a second signal transmitted from the central control room.
The first signal and the second signal are signals having different systems from each other.
The water pressure control unit according to claim 1. The blast valve opens after receiving the first signal transmitted from the main control room and before a predetermined time elapses.
The first solenoid valve opens after a predetermined time has elapsed after receiving the first signal.
The second solenoid valve opens when it receives the second signal transmitted from the central control room.
The first signal and the second signal are signals having different systems from each other.
The water pressure control unit according to claim 1. The first solenoid valve opens after receiving the first signal transmitted from the main control room and before a predetermined time elapses.
The blast valve opens after the predetermined time has elapsed after receiving the first signal.
The second solenoid valve opens when it receives the second signal transmitted from the central control room.
The first signal and the second signal are signals having different systems from each other.
The water pressure control unit according to claim 1. At least one of the first solenoid valve and the second solenoid valve includes two solenoids that control opening and closing.
The water pressure control unit according to any one of claims 1 to 4. At least one of the first solenoid valve and the second solenoid valve is configured by connecting two solenoid valves including one solenoid for controlling opening and closing in series.
The water pressure control unit according to any one of claims 1 to 4. An electric valve is provided in place of the second solenoid valve.
The motorized valve opens after the predetermined time has elapsed after receiving the first signal.
The water pressure control unit according to claim 2. An electric valve is provided instead of the blast valve.
The motorized valve opens when it receives the second signal.
The water pressure control unit according to claim 2. An electric valve is provided in place of the first solenoid valve.
The motorized valve opens after the predetermined time has elapsed after receiving the first signal.
The water pressure control unit according to claim 3. An electric valve is provided in place of the second solenoid valve.
The motorized valve opens when it receives the second signal.
The water pressure control unit according to claim 3. An electric valve is provided instead of the blast valve.
The motorized valve opens after the predetermined time has elapsed after receiving the first signal.
The water pressure control unit according to claim 4. An electric valve is provided in place of the second solenoid valve.
The motorized valve opens when it receives the second signal.
The water pressure control unit according to claim 4.

Images