JPH06337295A - Hydraulic system for driving control rod - Google Patents

Abstract

PURPOSE:To prevent the erroneous function of a control rod driving mechanism during periodic inspection by providing a remote control valve for closing a cooling water stop valve when the pressure difference between a nuclear reactor and the inlet of a cooling water line, line measured by a differential manometer, exceeds a set value. CONSTITUTION:A cooling water stop valve 25 disposed in a cooling water line 4 is a remote control valve and when the pressure difference between a nuclear reactor 14 and the inlet of the cooling water line 4 exceeds a set value, a pressure difference signal 31 is delivered from a differential manometer 18 disposed in an instrumentation line 40. The cooling water stop valve 25 is closed automatically by the pressure difference signal 31. Consequently, even if an operator conducts the remote control of a hydraulic pressure control unit 7 while missing the closing operation of a return line stop valve 20, the differential manometer 18 detects the increase of cooling water supply pressure and interrupt the circuit between a control rod driving water pump 3 and the hydraulic control unit 7 thus preventing erroneous function of the control rod driving mechanism 8. The pump 3 is protected by providing a minimum flow line 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control rod drive hydraulic system facility for preventing malfunction of a control rod drive mechanism of a boiling water reactor.

[0002]

2. Description of the Related Art Generally, in a boiling water reactor, a control rod is inserted or pulled out from below the core which is contained in the reactor and generates heat by a fission reaction.
The output of the nuclear reactor is adjusted by adjusting the absorption amount of neutrons used for fission reaction. The number of control rods to be loaded varies depending on the size of the reactor, but is about several tens to one hundred and several tens.

The control rod is inserted / pulled out by a control rod drive mechanism connected to the lower end of the control rod. The control rod drive mechanism is driven by water pressure, and the drive water therefor is supplied from the control rod drive water pressure system equipment via the water pressure control unit. In addition, the cooling water to protect the seal ring used for the sliding part inside the control rod drive mechanism and the reed switch for position indication from the high temperature reactor is also controlled by the control rod drive hydraulic system via the hydraulic control unit. Supplied from equipment. The number of control rod drive mechanisms and water pressure control units is the same as that of the control rods.

A conventional example of control rod drive hydraulic system equipment will be described below with reference to FIG. This control rod drive water pressure system equipment is used during the periodic inspection in which the reactor 14 stops condensate supplied from the turbine equipment (not shown) via the spillover line 1 during the operation of the reactor 14. Condensed water in the condensate storage tank 2 is used as a water source. Condensed water introduced from this water source is boosted by the control rod drive water pump 3. As the water source, the condensate of the condensate storage tank may be used instead of the condensate storage tank 2 depending on the plant.

The condensate whose pressure has been increased branches from the system line 30 into a cooling water line 4, a driving water line 5, and a filling water line 6.
Are guided to the water pressure control unit 7 through the following three routes (hereinafter, condensate supplied by the cooling water line, the driving water line, and the filling water line are referred to as cooling water, driving water, and filling water, respectively).

Of these, the control rod drive mechanism 8 is used as cooling water.
0.7 to 1.3 liters per minute are supplied to each unit of the flow rate signal 29 of the flow meter 9 provided in the system line 30 and the flow rate signal 29 is provided downstream of the flow meter 9. It is constantly maintained by being transmitted to the flow rate adjusting valve 10 and controlling its opening. On the upstream side and the downstream side of the flow rate adjusting valve 10, a flow rate adjusting valve front valve 11 and a flow rate adjusting valve rear valve 1 are provided to facilitate maintenance and inspection work.
Two are provided. A cooling water stop valve 13 is provided in the cooling water line 4 and is a manual valve like the flow rate adjusting valve front valve 11 and the flow rate adjusting valve rear valve 12.

Further, the drive water is passed only when the control rod drive mechanism 8 is inserted or withdrawn. In order to drive the control rod drive mechanism 8 normally, it is necessary to set the supply pressure of the drive water higher than the pressure of the nuclear reactor 14 by a predetermined value. Therefore, the branch portion of the drive water line 5 of the system line 30. The pressure is adjusted by the pressure adjusting valve 15 arranged on the further downstream side.

Further, the filling water is supplied to a high pressure water in an accumulator (not shown) in the water pressure control unit 7 in case the control rod drive mechanism 8 is rapidly inserted in order to urgently stop the nuclear fission reaction in the nuclear reactor 14. Water to fill. Therefore, once the filling is completed, there is no flow until the filling becomes necessary again.

The upstream side and the downstream side of the control rod driving water pump 3 are bypassed by the minimum flow line 16, and the deadline operation of the control rod driving water pump 3 is prevented and dew condensation is formed on the pipe surface on the downstream side of the control rod driving water pump 3. The condensate temperature is raised to such an extent that no Further, the control rod driving water pump 3 supplies the cooling water, the driving water, and the filling water to the water pressure control unit 7 as well as the reactor recirculation pump (not shown) and the reactor coolant purification via the purge line 17. It also has a function of supplying purge water to a system pump (not shown).

If the supply pressure of the cooling water is too low with respect to the pressure of the nuclear reactor 14, a predetermined cooling water flow rate cannot be obtained, and if it is too high, an inappropriate water pressure may be applied to the control rod drive mechanism 8 to cause a malfunction. There is. Therefore, the differential pressure gauge 18 is provided in the instrumentation line 40 that guides the pressures at the inlet of the reactor 14 and the cooling water line 4 so that it can be monitored that the difference between these pressures is maintained at an appropriate value. In particular, when performing maintenance work on the water pressure control unit 7 or the control rod drive mechanism 8 during the periodic inspection, it is necessary to isolate the water pressure control units 7 one by one. Focus on the control unit 7. Therefore, there is a possibility that only the corresponding control rod drive mechanism 8 may malfunction due to an increase in cooling water supply pressure.

In order to prevent this phenomenon, a return line 19 is provided which branches from the cooling water line 4 and is connected to the reactor return line (not shown) of the reactor coolant purification system to isolate the water pressure control unit 7. When performing work, the cooling water supply pressure is increased by bypassing the cooling water from the return line 19 to the reactor 14 via the reactor coolant purification system and the reactor water supply system (not shown). The operation is to prevent. The return line 19 is provided with a manual return line stop valve 20 so that the cooling water is not bypassed during normal operation.

[0012]

In the conventional control rod drive hydraulic system equipment described above, when the isolation work of the water pressure control unit and the maintenance inspection work of the reactor coolant purification system or the reactor water supply system overlap with each other. Is impenetrable to the return line,
Alternatively, there is a possibility that the control rod drive mechanism malfunctions due to an increase in the cooling water supply pressure due to the operator not operating the return line stop valve in a situation where water can pass. Further, if the control rod drive water pump that is the pressurizing source is stopped, the above-mentioned control rod drive mechanism may not malfunction,
If only some of the water pressure control units are isolated, or if the reactor recirculation pump or reactor coolant purification system pump is operating and it is necessary to supply purge water to these pumps, control rod drive water The pump cannot be stopped.

The present invention has been made in view of the above conventional circumstances, and an object thereof is to provide a control rod drive hydraulic system facility for preventing malfunction of the control rod drive mechanism during a periodic inspection.

[0014]

In order to achieve the above object, the control rod drive hydraulic system equipment of the present invention is a control rod drive mechanism for controlling the output of a boiling water reactor according to the invention of claim 1. A system line for supplying water and cooling water, a drive water line branched from this system line for guiding drive water to the control rod drive mechanism, and a cooling water line for guiding cooling water to the control rod drive mechanism and having a cooling water stop valve , A flow rate adjusting valve that is installed in the system line and that adjusts the flow rates of the driving water and the cooling water and has front and rear valves on the upstream and downstream sides, respectively, and the difference between the reactor and the inlet of the cooling water line. Control rod drive water pressure provided with a differential pressure gauge for measuring pressure and a return line branched from a system line to guide the coolant to a reactor coolant purification system and prevent the differential pressure from rising and having a return line stop valve Cooling in system equipment Valve is intended to provide a control rod drive hydraulic system facility, which is a remotely operated valve for closing operation when the differential pressure of the differential pressure gauge is equal to or larger than a set value.

According to a second aspect of the present invention, instead of the cooling water stop valve being a remote control valve, a cooling water stop valve bypass line that bypasses the cooling water stop valve and the cooling water stop valve bypass line. And a cooling water stop valve bypass valve, wherein the cooling water stop valve bypass valve is a remote operated valve that closes when the differential pressure of the differential pressure gauge exceeds a set value. The control rod drive hydraulic system facility according to claim 1 is provided.

According to a third aspect of the invention, instead of the cooling water stop valve being a remote control valve, a remote control for closing the flow rate adjusting valve when the differential pressure of the differential pressure gauge exceeds a set value. The control rod drive hydraulic system facility according to claim 1, characterized in that it is an operation valve.

According to a fourth aspect of the present invention, instead of the cooling water stop valve being a remote control valve, the front valve or the rear valve is closed when the differential pressure of the differential pressure gauge exceeds a set value. The control rod drive hydraulic system facility according to claim 1, wherein the remote control valve is used.

According to the fifth aspect of the invention, instead of the cooling water stop valve being a remote control valve, the return line stop valve is opened when the differential pressure of the differential pressure gauge exceeds a set value. A control rod drive hydraulic system facility according to claim 1, characterized in that it is a remote control valve.

According to a sixth aspect of the invention, instead of the cooling water stop valve being a remote control valve, there is a connecting line for guiding the cooling water to the condensate storage tank and having a connecting line stop valve,
2. The control rod drive hydraulic system facility according to claim 1, wherein the connecting line stop valve is a remote operated valve that opens when the differential pressure of the differential pressure gauge exceeds a set value. is there.

[0020]

[Operation] In the control rod drive hydraulic system equipment having the above configuration,
When the differential pressure between the reactor and the inlet of the cooling water line exceeds the set value, the valve between the control rod drive water pump and the hydraulic pressure control unit is automatically closed by the differential pressure signal generated by the differential pressure gauge. By closing this valve, the supply pressure is shut off to prevent the control rod drive mechanism from malfunctioning due to an increase in the cooling water supply pressure. Or, in the case where the valve on the line other than the water pressure control unit is provided, when the pressure difference between the reactor and the cooling water line inlet exceeds the set value, the pressure difference signal generated by the differential pressure gauge automatically Open operation. By opening the valve, an excessive pressure is released to prevent the control rod drive mechanism from malfunctioning due to an increase in the cooling water supply pressure.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of control rod drive hydraulic system equipment according to the present invention will be described below with reference to FIG. In the following FIGS. 1 to 6, the same parts as those in FIG.

In this embodiment, the cooling water stop valve 25 arranged in the cooling water line 4 is used as a remote control valve, and when the differential pressure between the reactor 14 and the inlet of the cooling water line 4 exceeds a set value. The differential pressure signal 3 from the differential pressure gauge 18 arranged on the instrumentation line 40.
1 is transmitted, and the cooling water stop valve 2 is generated by this differential pressure signal 31.
5 automatically closes.

As a result, even if the worker forgets to open the return line stop valve 20 during the periodic inspection and performs the isolation work of the water pressure control unit 7, the differential pressure gauge 18 increases the cooling water supply pressure. Is detected and the control rod drive water pump 3 and the water pressure control unit 7 are shut off from each other, so that the control rod drive mechanism 8 can be prevented from malfunctioning. Even if the discharge side of the control rod drive water pump 3 is shut off, water is passed through the minimum flow line 16 so that the control rod drive water pump will not be damaged by the shutoff operation.

Next, a second embodiment of the control rod drive hydraulic system equipment according to the present invention will be described with reference to FIG. In this embodiment, a cooling water stop valve bypass line 23 that bypasses the cooling water stop valve 13 is provided in the cooling water line 4, and the cooling water stop valve bypass valve 21 is provided on the cooling water stop valve bypass line 23.

In the second embodiment thus constructed, the cooling is performed by the differential pressure signal 32 generated by the differential pressure gauge 18 when the differential pressure between the reactor 14 and the inlet of the cooling water line 4 exceeds the set value. The water stop valve bypass valve 21 is closed. The cooling water stop valve 13 is closed during the regular inspection and opened during the normal operation of the reactor 14.

As a result, in addition to the effect equivalent to that of the first embodiment, the cooling water stop valve bypass valve 21 due to an erroneous signal from the differential pressure gauge 18 during the normal operation of the reactor 14.
Even if is closed, since the cooling water stop valve 13 is in the open state, there is also an effect that there is no problem in supplying cooling water to the water pressure control unit 7.

Next, a third embodiment of the control rod drive hydraulic system equipment according to the present invention will be described with reference to FIG. In this embodiment, when the differential pressure between the reactor 14 and the inlet of the cooling water line 4 becomes equal to or higher than the set value, the differential pressure signal 33 generated by the differential pressure gauge 18 is generated.
As a result, the flow rate adjusting valve 26 arranged in the system line 30 automatically closes.

As a result, the same effect as that of the first embodiment can be obtained. Further, a fourth embodiment of the control rod drive hydraulic system facility according to the present invention will be described with reference to FIG.

In this embodiment, the flow control valve front valve 27 installed upstream of the flow control valve 10 arranged in the system line 30 is used as a remote control valve, and the reactor 14 and the cooling water line 4 are connected.
When the differential pressure with the inlet reaches a set value, the differential pressure signal 34 generated by the differential pressure gauge 18 is transmitted to the flow rate regulating valve front valve 27 so that the flow rate regulating valve front valve 27 is closed.

As a result, the same effect as that of the first embodiment can be obtained. Needless to say, the same effect can be obtained even if the flow control valve rear valve 12 installed on the downstream side of the system line 30 is used as the remote control valve instead of the flow control valve front valve 27.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
It will be described based on. In the present embodiment, the return line stop valve 28 provided in the return line 19 connected to the downstream side of the system line 30 is used as a remote control valve, and the differential pressure between the reactor 14 and the cooling water line 4 inlet is set. The return line stop valve 28 is opened by the differential pressure signal 35 generated by the differential pressure gauge 18 when the value exceeds the set value.

As a result, even when the worker forgets to open the return line stop valve 28 during the periodic inspection and performs the isolation work of the water pressure control unit 7, the increase in the cooling water supply pressure is measured by the differential pressure gauge. It is possible for 18 to detect and pass water to the return line 19. At the same time, the cooling water supply pressure is reduced, so that the control rod drive mechanism 8 can be prevented from being erroneously operated.

Finally, a sixth embodiment of the control rod drive hydraulic system equipment according to the present invention will be described with reference to FIG. In the present embodiment, the system line 30 downstream of the inlet of the cooling water line 4
A communication line 22 is provided that branches from this to the condensate storage tank 2.
A communication line stop valve 24 that can be remotely operated is provided on the same line. When the pressure difference between the reactor 14 and the inlet of the cooling water line 4 exceeds the set value, the communication line stop valve 24 is opened by the pressure difference signal 36 generated by the pressure difference gauge 18.

As a result, even if the worker forgets to open the return line stop valve 20 during the regular inspection and performs the isolation work of the water pressure control unit 7, the increase in the cooling water supply pressure is measured by the differential pressure gauge. 18 detects and the connecting line stop valve 24 opens, so that the cooling water supply pressure can be reduced.

[0035]

As described above, in the control rod drive hydraulic system facility of the present invention, it is possible to prevent malfunction of the control rod drive mechanism during the periodic inspection, and thus the soundness of the control rod drive hydraulic system facility is improved. It is possible to improve the sex.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a first embodiment of a control rod drive hydraulic system facility according to the present invention.

FIG. 2 is a system configuration diagram showing a second embodiment of control rod drive hydraulic system equipment according to the present invention.

FIG. 3 is a system configuration diagram showing a third embodiment of a control rod drive hydraulic system facility according to the present invention.

FIG. 4 is a system configuration diagram showing a fourth embodiment of control rod drive hydraulic system equipment according to the present invention.

FIG. 5 is a system configuration diagram showing a fifth embodiment of a control rod drive hydraulic system facility according to the present invention.

FIG. 6 is a system configuration diagram showing a sixth embodiment of control rod drive hydraulic system equipment according to the present invention.

FIG. 7 is a system configuration diagram showing a conventional example of control rod drive hydraulic system equipment.

[Explanation of symbols]

4 ... Cooling water line 5 ... Driving water line 10 ... Flow rate adjusting valve 11 ... Flow rate adjusting valve front valve 12 ... Flow rate adjusting valve rear valve 13 ... Cooling water stop valve 14 ... Reactor 18 ... Differential pressure gauge 19 ... Return line 20 ... Return Line stop valve 21 ... Cooling water stop valve bypass valve 22 ... Communication line 23 ... Cooling water stop valve bypass line 24 ... Communication line stop valve 25 ... Cooling water stop valve 26 ... Flow rate adjusting valve 27 ... Flow rate adjusting valve front valve 28 ... Return Line stop valve 30 ... System line 31 ... Differential pressure signal 32 ... Differential pressure signal 33 ... Differential pressure signal 34 ... Differential pressure signal 35 ... Differential pressure signal 36 ... Differential pressure signal

Claims (6)

[Claims] 1. A system line for supplying drive water and cooling water to a control rod drive mechanism for controlling the output of a boiling water reactor,
A drive water line that branches from this system line to guide the drive water to the control rod drive mechanism, a cooling water line that guides cooling water to the control rod drive mechanism and has a cooling water stop valve, and drive water and cooling water provided in the system line From the system line, a flow rate adjustment valve that adjusts the flow rate of the In a control rod drive hydraulic system facility comprising a branch line for guiding the coolant to a reactor coolant purification system and preventing the rise of the differential pressure, and a return line having a return line stop valve, the cooling water stop valve is A control rod drive hydraulic system facility characterized in that it is a remote operated valve that closes when the differential pressure of the differential pressure gauge exceeds a set value. 2. A cooling water stop valve bypass line that bypasses the cooling water stop valve, and a cooling provided in the cooling water stop valve bypass line, instead of the cooling water stop valve being a remote control valve. 2. A water stop valve bypass valve, wherein the cooling water stop valve bypass valve is a remote control valve that closes when the differential pressure of the differential pressure gauge exceeds a set value. Control rod drive hydraulic system equipment. 3. The cooling water stop valve is a remote control valve instead of a remote control valve, and the flow rate adjusting valve is a remote control valve that closes when the differential pressure of a differential pressure gauge exceeds a set value. The control rod drive hydraulic system facility according to claim 1. 4. Instead of the cooling water stop valve being a remote control valve, the front valve or the rear valve is a remote control valve that closes when the differential pressure of a differential pressure gauge exceeds a set value. The control rod drive hydraulic system facility according to claim 1, wherein 5. Instead of the cooling water stop valve being a remote control valve, the return line stop valve is a remote control valve that opens when the differential pressure of a differential pressure gauge exceeds a set value. The control rod drive hydraulic system facility according to claim 1. 6. Instead of the cooling water stop valve being a remotely operated valve, the cooling water stop valve has a communication line for guiding the cooling water to the condensate storage tank, the communication line having a communication line stop valve, the communication line stop valve having the connection line stop valve. The control rod drive hydraulic system facility according to claim 1, wherein the remote control valve is opened when the differential pressure of the pressure gauge exceeds a set value.