JPH04172293A - Cooling system during reactor isolation - Google Patents

Abstract

PURPOSE:To increase volume margin in suppression chamber space by providing a level meter to detect the upper limit of usable zone of suppression pool and temperature meter to detect the water temperature on coolant inlet side of an auxiliary machine requiring coolant. CONSTITUTION:When the water level in a suppression pool 2 reach the upper limit of usable zone of the suppression pool 2, it is detected by a level meter 9 and the detection signal is sent to a controller 11. Meanwhile, the water temperature at the coolant inlet of a lubricant cooler 6 is detected by a temperature meter 10, and the detected signal is sent to the controller 11. The controller 11 automatically switches the coolant source to both of a condensed water reservoir tank 1 and the suppression pool 2. In this operation mode, the temperature of coolant supplied to a reactor 4 and the lubricant cooler 6 becomes low and the amount of coolant supplied from the suppression pool 2 becomes relatively large. By this, the volume margin in the suppression chamber space can be increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reactor isolation cooling system for a boiling water reactor, and in particular to a system for automatically switching the cooling water source after reactor isolation. This invention relates to a cooling system suitable for reactor isolation.

[Prior art] Figures 8 to 13 show the prior art, and Figure 8 is a system diagram of a reactor isolation cooling system, in which condensate storage is activated by a standby state and a low reactor water level signal. Figure 9 shows a state in which cooling water is being supplied from the tank; Figure 9 is a diagram showing a state in which cooling water is being supplied from the suppression pool when switching the water source when the water level of the suppression pool has reached the rated point;
Figure 10 is an explanatory diagram of control when switching the cooling water source between the condensate storage tank and the suppression pool;
The figure shows the relationship between the elapsed time after reactor isolation and the temperature of the suppression pool water, and Figure 12 shows the elapsed time after reactor isolation and the flow rate of cooling water from the condensate storage tank.
FIG. 13 is a diagram showing the relationship between the total amount of cooling water and the elapsed time after reactor isolation, the flow rate of cooling water from the suppression pool, and the water level of the suppression pool.

A conventional reactor isolation cooling system, as shown in FIGS. 8 and 9, has a condensate storage tank 1, which is a first water source, and a second water source.
Suppression pool 2, which is the water source for reactor isolation cooling system pump (hereinafter referred to as "RCIC pump") 3
, a reactor isolation cooling system turbine (hereinafter referred to as l'Rc IC turbine) 5 that drives this, and an RCIC from the condensate storage tank 1 via the first electric valve 14a.
a first cooling water supply line that sends cooling water to the pump 3; a second cooling water supply line that sends cooling water from the suppression pool 2 to the RCIC pump 3 via the second electric valve 14b; and the RCIC pump 3. It is equipped with a third cooling water supply line that pumps cooling water from the reactor 4 to the auxiliary lubricating oil cooler 6, and a manual switch 15 installed in the central control room.

In the conventional reactor isolation cooling system, after the reactor is isolated, cooling water is supplied to the reactor 4 and the lubricating oil cooler 6, which is an auxiliary machine, as follows.

First, when the reactor isolation cooling system is in a standby state, the first electric valve 14a is open and the second electric valve 1 is open, as shown in FIG.
4b is set to closed.

In this state, when the reactor 4 is isolated and the reactor isolation cooling system receives a signal indicating that the reactor water level is low, reactor steam is automatically supplied to the RCIC turbine 5, and this RCIC turbine 5 is driven. Drive the RCIC pump 3.

When the RCIC pump 3 is driven, cooling water is supplied from the condensate storage tank 1 through the first electric valve 14a,
The cooling water is pumped to the nuclear reactor 4 and the lubricating oil cooler 6 by the RCIC pump 3, and the rated flow rate of the cooling water is ensured in the nuclear reactor 4.

Since the reactor 4 is isolated, the reactor steam from the exhaust from the main steam relief safety valve 6 is inserted into the suppression pool 2, and the turbine exhaust from the RCIC turbine 5 is also inserted into the suppression pool 2, where they are condensed. . Therefore, the water level of the suppression pool 2 rises.

When the water level of the suppression pool 2 rises, an operator operates a manual switch 15 installed in the central control room when the water source switching condition is reached so as not to exceed the upper limit of the usage range shown in FIG. , from the state shown in FIG.
As shown in the figure, the second electric valve 14b is opened and the first electric valve 14a is closed. Thereby, cooling water is supplied from the suppression pool 2 through the second electric valve 14b, and the cooling water is pumped to the nuclear reactor 4 and the lubricating oil cooler 6 by the RCIC pump 3.

By the way, as mentioned above, the suppression pool 2 contains reactor steam and RC due to exhaust from the main steam relief valve 16.
Since the IC turbine exhaust is inserted and condensed, the 11th
As shown in the figure, the water temperature in the suppression pool 2 rises. Therefore, if cooling water is continued to be supplied from the suppression pool 2, the temperature of the cooling water supplied to the lubricating oil cooler 6 will rise, making it impossible to achieve the initial function.

Therefore, the operator must ensure that the temperature of the cooling water supplied to the lubricating oil cooler 6 does not exceed the upper limit of the usage range.

Operate the manual switch 15 to open the first electric valve 14a and close the second electric valve 14b, and as shown in FIG.
Cooling water is supplied through the RCIC pump 3, and the cooling water is again pumped to the nuclear reactor 4 and the lubricating oil cooler 6 by the RCIC pump 3.

Also, when the water level of suppression pool 2 rises,
The second electric valve 14 is operated so as not to exceed the upper limit of the usage range.
b is opened, the first electric valve 14a is closed, and the cooling water source is switched to the Sable and Tushion pool 2.

[Problems to be Solved by the Invention] In the prior art, when the water level in the suppression pool 2 rises after the reactor isolation cooling system is activated, the water source for supplying cooling water is transferred from the condensate storage tank 1 to the suppression pool 2.
When the temperature of the cooling water supplied to the lubricating oil cooler 6, which is an auxiliary device that requires cooling water, increases, the water source of the cooling water supply is switched from the suppression pool 2 to the condensing water source. An operator switches the source of cooling water to the storage tank 1 by operating a manual switch 15 in the central control room. Therefore, there is a problem in that the operator is required to have a high level of judgment and response operations.

Furthermore, in the conventional technology, the total amount of cooling water supplied from the condensate storage tank 1 is large, and the total amount of cooling water supplied from the suppression pool 2 is relatively small. As a result, the amount of water stored in the suppression pool 2 is large, and it is necessary to take care to ensure that a sufficient space volume of the suppression chamber can be obtained for safety even when this amount of water is large.

The first object of the present invention is to switch the water source from the condensate storage tank to the suppression pool in the supply of cooling water after reactor isolation, and to switch the water source from the suppression pool to the condensate storage tank by switching the water source from the suppression pool to the condensate storage tank. An object of the present invention is to provide a cooling system during nuclear reactor isolation that can automatically switch water sources depending on the water level and temperature, and takes into account the reduction in operator operations.

Furthermore, a second object of the present invention is to provide cooling during reactor isolation that can supply cooling water at an appropriate temperature to auxiliary equipment that requires cooling water, and further increase the margin of space volume of the suppression chamber. The aim is to provide a system.

[Means for Solving Problem iI1] The first object is to provide a water level gauge that detects the upper limit of the usage range of the suppression pool, and a thermometer that detects the water temperature on the cooling water inlet side of the auxiliary equipment. , taking in detection signals from the water level gauge and the thermometer respectively, and when the water level of the suppression pool reaches the upper limit of the usage range, opening the second flow rate regulating valve and closing the first flow rate regulating valve; When the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the usage range,
The first degree is achieved by installing a controller that controls the opening of the second flow rate regulating valve.

Further, the first purpose is to provide a condensate storage tank which is a first water source, a suppression pool which is a second water source, and a first water source. a second RCIC pump, a first cooling water supply line that sends cooling water from the condensate storage tank to the first RCIC pump via a first electric valve; Second RC'I C via valve
a second cooling water supply line that sends cooling water to the pump; and a third cooling water supply line that pumps cooling water from the first RCIC pump to the reactor and auxiliary equipment via the first flow rate adjustment valve; a fourth cooling water supply line that pumps cooling water from the second RCIC pump to the reactor via the second flow rate regulating valve; The first RCIC pump on the suction side of the second RCIC pump. A bypass line and a bypass valve connecting the second cooling water supply lines are provided, a water level gauge is provided to detect the upper limit of the usage range of the suppression pool, and a thermometer is provided to detect the water temperature on the cooling water inlet side of the auxiliary equipment. is installed, receives detection signals from the water level gauge and the thermometer, and when the water level of the suppression pool reaches the upper limit of the usage range, opens the second electric valve and closes the first electric valve. , when the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the usage range, the first. The second electric valve is also opened, and the bypass valve is closed. And the first. This can also be achieved by installing a controller that controls the opening of the second flow rate regulating valve.

Furthermore, the second objective is the first objective. a second flow rate regulating valve, a first. In the open mode of the second electric valve and the bypass valve, the controller controls the first electric valve so that the water temperature on the cooling water inlet side of the auxiliary equipment falls within a predetermined control range. Second
The opening degree of the flow rate adjustment valve.

1st. Controls opening and closing of the second electric valve and bypass valve.

This is achieved by reducing the total amount of cooling water used from the condensate storage tank and making adjustments to suppress an increase in the amount of water in the suppression pool.

[Function] Also in the invention according to claim 1 of the present invention, in the standby state, the first flow rate regulating valve is set to open, and the second flow rate regulating valve is set to closed.

In this set state, when a low reactor water level signal is received after reactor isolation, the RCIC pump is driven and cooling water is automatically sent from the condensate storage tank to the RCIC pump via the first flow rate adjustment valve. This cooling water is pumped by the RCIC pump to the reactor and auxiliary equipment that requires cooling water, ensuring a rated flow rate to the reactor.

Next, when the water level of the suppression pool rises and reaches the upper limit of the usage range of the suppression pool, the water level gauge detects this and sends a detection signal to the controller. In the said controller.

A detection signal indicating that the water level of the suppression pool has reached the upper limit of the usage range is received from the water level gauge, and the second flow rate regulating valve is opened and the first flow rate ga valve is operated to close. As a result, cooling water is automatically sent from the suppression pool to the RCIC pump via the second flow rate regulating valve, and this cooling water is also pumped from the RCIC pump to the reactor and auxiliary equipment.

During this time, the water temperature is detected by a thermometer on the cooling water inlet side of the auxiliary equipment, and the detection signal is sent to the controller. The controller receives a water temperature detection signal from the thermometer and compares the temperature of the cooling water with the upper limit of the usage range. Then, when the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the usage range, the controller controls the first controller. The opening degree of the second flow rate regulating valve is operated. As a result, cooling water is automatically sent from the condensate storage tank to the RCIC pump via the first flow rate adjustment valve, and at the same time, cooling water is sent from the suppression pool to the RCIC pump via the second flow rate adjustment valve. This mixed cooling water is pumped from the RCIC pump to the reactor and auxiliary equipment.

Therefore, the auxiliary equipment is supplied with lower-temperature cooling water that is mixed with the cooling water sent from the condensate storage tank than when cooling water is supplied only from the suppression pool.

Additionally, when the water temperature on the cooling water inlet side of the auxiliary equipment rises, the cooling water source is switched and the cooling water from the suppression pool is mixed with the cooling water from the condensate storage tank and supplied. The amount of cooling water supplied from the suppression pool becomes relatively large. Therefore, the margin of spatial volume of the subrepression chamber can be increased.

Further, in the second aspect of the present invention, the first motor-operated valve is set to open and the second motor-operated valve is set to close in the standby state.

In this state, when a low reactor water level signal is received, cooling water is automatically sent from the condensate storage tank to the first cooling water supply line having the first electric valve; The cooling water is sent from the supply line to the first RCIC pump, while passing through the bypass line and bypass valve to the second RCIC pump.
is sent to the IC pump, and the first. The third RCIC pump is activated by the second RCIC pump. The fourth cooling water supply line and the first. It is pumped to the nuclear reactor via the second flow rate regulating valve. Further, cooling water is pumped to the auxiliary equipment from a third cooling water supply line.

Next, when the water level of the suppression pool rises and reaches the upper limit of the usage range of the suppression pool, the water level gauge detects this and sends the detection signal to the controller. When the controller receives a detection signal from the water level gauge indicating that the water level of the suppression pool has reached the upper limit of the usage range, it operates the second motor-operated valve to open and the first motor-operated valve to close. This automatically routes cooling water from the suppression pool to a second cooling water supply line with a second motorized valve, which is then routed to the second RCIC pump while passing through the bypass line and bypass valve. The first RCIC pump is also sent to the first RCIC pump. Second
The 3rd and 4th cooling water supply lines from the RCIC pump and the 1st. Cooling water is supplied to the reactor via the second flow rate regulating valve. Further, cooling water is pumped to the auxiliary equipment from a third cooling water supply line.

During this time, the water temperature on the cooling water inlet side of the auxiliary equipment is detected by a thermometer, and the detection signal is sent to the controller. The controller takes in the water temperature detection signal from the thermometer and compares it with the upper limit of the cooling water usage range. As a result of the comparison, if the cooling water temperature reaches the upper limit of the usage range,
1st. Operate both the second electric valve to open. Also, the bypass valve is operated to close. This automatically connects the condensate storage tank → the first cooling water supply line with the first electric valve → the first R, CIC pump → the third cooling water supply line and the first flow rate regulating valve. Mainly low-temperature cooling water is supplied to the reactor and auxiliary equipment, and at the same time a suppression pool →
Cooling water is supplied to the reactor through a second cooling water supply line having a second electric valve→a cooling water supply line of the second RCICCIC pump and a second flow rate regulating valve.

Therefore, while only the low-temperature cooling water from the condensate storage tank is supplied to the auxiliary equipment, mixed water from the suppression pool and the condensate storage tank is supplied to the reactor.

In this case, since the amount of cooling water supplied from the suppression pool is relatively increased, the margin of spatial volume of the suppression chamber can be increased.

In the invention according to claim 3 of the present invention, the first aspect of claim 1. When both the second flow rate regulating valves are in the opening operation mode, the controller controls the first and second flow rate regulating valves so that the water temperature on the cooling water inlet side of the auxiliary equipment falls within a predetermined control range. The opening degree of the second flow rate regulating valve is adjusted.

In other words, when the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the control range, the opening degree of the first flow rate adjustment valve is increased, the opening degree of the second flow rate adjustment valve is decreased, and the condensate water is - Supply a large amount of cooling water from the storage tank to prevent the water temperature from exceeding the upper limit of the control range.

In addition, when the water temperature on the cooling water inlet side of the auxiliary equipment reaches the lower limit of the control range, the opening degree of the second flow rate adjustment valve is increased, the opening degree of the first flow rate adjustment valve is decreased, and suppression is applied. A large amount of cooling water is supplied from the pool to further increase the space capacity margin of the suppression chamber.

Also, the first aspect of claim 2. When the temperature of the auxiliary cooling water reaches a predetermined set value for both the second flow rate adjustment valve, the opening adjustment mode is entered and the bypass valve is closed. The second flow regulating valve maintains a constant supply of cooling water to the reactor, the first flow regulating valve is controlled in the open direction, the second flow regulating valve is controlled in the closing direction, and condensate is stored in the auxiliary equipment. Secure low-temperature cooling water from the tank, adjust the amount of cooling water used for the reactor from the suppression pool, and further increase the space capacity margin of the suppression chamber.

Thereby, it is possible to supply cooling water at an appropriate temperature to the auxiliary equipment, and it is also possible to increase the margin of spatial volume of the suppression chamber.

The technology related to this type of reactor isolation cooling system is disclosed in Japanese Patent Application Laid-open No. 143992/1982 and Japanese Patent Application Laid-Open No. 1999-1-
There is a technique described in Japanese Patent No. 53196.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show a first embodiment of the present invention,
Figure 1 is a system diagram of the cooling system during reactor isolation, Figure 2 is a flowchart of water source switching control, and Figure 3 shows the elapsed time after reactor isolation and the flow rate of cooling water from the condensate storage tank. Figure 4 shows the relationship between the total amount of cooling water sent from the condensate storage tank and the total amount of cooling water sent from the suppression pool. A diagram showing the relationship with the total amount of water,
FIG. 5 is a diagram showing the relationship between the water temperature on the cooling water inlet side of the lubricating oil cooler, which is an auxiliary device, and the control range.

In the nuclear reactor isolation cooling system of the embodiment shown in these figures, the same members as in the prior art shown in FIGS. 8 and 9 are designated by the same reference numerals, and further explanation thereof will be omitted.

In the nuclear reactor isolation cooling system of this embodiment, as shown in FIG. A thermometer 10 is provided on the side, and a controller 11 is also provided.

The controller 11 includes a first electric valve 14a provided in a first cooling water supply line connecting the condensate storage tank 1, which is a first water source, and the RCIC pump 3, and a first electric valve 14a, which is a second water source. A second electric valve 14b provided in a second cooling water supply line connecting the suppression pool 2 and the RCIC pump 3 is connected to the water level gauge 9 and the thermometer 10.

When the water level gauge 9 detects at least the upper limit of the usage range of the suppression pool 2, it sends a detection signal to the controller 11.

The thermometer 10 detects the water temperature on the cooling water inlet side of the lubricating oil cooler 6 and sends the detection signal to the controller 11.

When the water level of the cooling water in the suppression pool 2 reaches the upper limit of the usage range of the suppression pool 2, the controller 11 receives a detection signal from the water level gauge 9 and opens the second flow rate regulating valve 8. , the first flow rate regulating valve 7 is closed, the cooling water source is switched from the condensate storage tank 1 to the suppression pool 2, and a detection signal of the water temperature on the cooling water inlet side of the lubricating oil cooler 6 is sent from the thermometer 10. and compare that water temperature with the upper limit of the cooling water usage range.
When this upper limit is reached, the first. second flow regulating valve 7,
8 to switch the cooling water source to both the condensate storage tank 1 and the suppression pool 2.

The reactor isolation cooling system of the above embodiment is operated and functions as follows.

That is, after the reactor is isolated, the first flow rate regulating valve 7 is automatically opened in response to a low reactor water level signal, and as shown in FIG. The water is sent to the RCIC pump 3 via the flow rate adjustment valve 7, and from the RCIC pump 3 to the nuclear reactor 4 and lubricating oil cooler 6, ensuring a rated flow rate of cooling water in the reactor 4.

During this time, reactor steam and RCIC turbine exhaust from the main steam relief safety valve 16 are inserted into the suppression pool 2 and condensed. Therefore, the water level in the suppression pool 2 rises. In addition, the temperature of the cooling water in the suppression pool 2 rises, causing the condensate storage tank 1 to
The water temperature will be higher than the cooling water inside.

Eventually, when the water level in the suppression pool 2 reaches the upper limit of the usage range of the suppression pool 2, this is detected by the water level gauge 9.

A signal is sent to controller 11. Therefore, as shown in FIG. 2, the controller 11 takes in the detection signal from the water level gauge 9, opens the second flow rate regulating valve 8,
The flow rate adjustment valve 7 is closed to automatically switch the cooling water source from the condensate storage tank 1 to the suppression pool 2. By switching the water source, as shown in Figure 4,
Cooling water is sent from the suppression pool 2 to the RCIC pump 3 via the second flow rate adjustment valve 8, and this cooling water is
It is pumped from the IC pump 3 to the nuclear reactor 4 and lubricating oil cooler 6.

During this time, the water temperature on the cooling water inlet side of the lubricating oil cooler 6 is detected by the thermometer 10, and the detection signal is sent to the controller 11.
sent to. This controller 11 takes in the water temperature detection signal from the thermometer 10 and compares it with the upper limit of the cooling water usage range. As a result of the comparison, as shown in FIG. 2, when the water temperature on the cooling water inlet side of the lubricating oil cooler 6 reaches the upper limit value, the controller 11 switches to the first. The opening degrees of both the second flow rate regulating valves 7 and 8 are manipulated to automatically switch the cooling water source to both the condensate storage tank 1 and the suppression pool 2. In this water source switching state, FIG.

As can be seen from FIGS. 3 and 4, cooling water is sent from the condensate storage tank 1 to the first flow regulating valve 7 to the RCIC pump 3, while the cooling water is sent from the pressure boule 2 to the second flow regulating valve 8. → Cooling water is sent to the RCIC pump 3, and the cooling water, which is a mixture of the cooling water in the condensate storage tank 1 and the cooling water sent from the suppression pool 2, is sent from the RCIC pump 3 to the reactor 4 and lubricating oil cooler 6. be pumped. Therefore, in this mode of operation, the condensate storage tank 1 is in the cooling water.
Since the cooling water supplied from the reactor 4 is mixed in, the temperature of the cooling water supplied to the nuclear reactor 4 and the lubricating oil cooler 6 is lowered accordingly.

In addition, during operation after switching the water source due to the water temperature on the cooling water inlet side of the lubricating oil cooler 6 reaching the upper limit of the usage range, the cooling water source is not only the condensate storage tank 1 but also the suppression pool 2. It also supplies cooling water. the result.

Compared to the prior art, the total amount of cooling water supplied from the condensate storage tank 1 is small, and the total amount of cooling water supplied from the suppression pool 2 is relatively large.

Thereby, the margin of spatial volume of the suppression chamber can be increased.

Furthermore, in this embodiment, as shown in FIG. 5, a control range is set during operation after switching the water source based on the water temperature on the cooling water inlet side of the lubricating oil cooler 6, and this control range is stored in the controller 11. Then, the controller 11 adjusts the opening degrees of the first and second flow rate regulating valves 7 and 8 so that the water temperature on the cooling water inlet side of the lubricating oil cooler 6 falls within the control range.

That is, when the water temperature on the cooling water inlet side of the lubricating oil cooler 6 reaches the upper limit of the control range, the opening degree of the first flow rate regulating valve 7 is increased, and the opening degree of the second flow rate regulating valve 8 is increased. Make it smaller. Further, when the lower limit of the control range is reached, the opening degree of the second flow rate regulating valve 8 is increased and the opening degree of the first flow rate regulating valve 7 is decreased.

Thereby, the temperature of the cooling water supplied to the lubricating oil cooler 6 can be maintained at an appropriate level, and the margin of spatial volume of the suppression chamber can be further increased.

Next, FIGS. 6 and 7 show other embodiments of the present invention, in which FIG. 6 is a system diagram of a cooling system during reactor isolation, and FIG. 7 is a flowchart of water source switching control.

In the reactor isolation cooling system of this embodiment, the first and second R
CIC pumps 3a and 3b are provided.

Said 1st. The second RCIC pumps 3a and 3b are driven by one RCIC turbine 5.

The condensate storage tank 1, which is the first water source, and the first RCIC pump 38 are connected by a first cooling water supply line having a first electric valve 14a. Suppression pool 2 which is the second water source and second RCICCIC pump 3a
It is connected by a second cooling water supply line having a second electric valve 14b. The first RCIC pump 3a and the nuclear reactor 4 are connected by a third cooling water supply line having a first flow rate regulating valve 7. A cooling water supply line is branched from the third cooling water supply line to the lubricating oil cooler 6, and a thermometer IO is provided in this cooling water supply line. The second RCJC pump 3b and the nuclear reactor 4 are connected by a fourth cooling water supply line having a second flow rate regulating valve 8. Between the first and second cooling water supply lines, there is a line between the first and second cooling water supply lines. They are connected by a bypass line 12 on the suction side of the second RCIC pumps 3a and 3b,
This bypass line 12 is provided with a bypass valve 13 . Said bypass valve 13. First electric valve 14a, second electric valve 14b, first flow rate adjustment valve 7. Second flow regulating valve8. Water level gauge 9 and thermometer 10 are connected to controller 11.

The other structure of the embodiment shown in FIG. 6 is the same as that of the embodiment shown in FIG. 1.

In the reactor isolation cooling system of the embodiment shown in FIG. 6, in the standby state, as shown in the following table, the first electric valve 14
a is open, the second electric valve 14b is closed, and the bypass valve 13 is set to open. In addition, the first and second flow rate regulating valves 7
, 8 are set with their opening degrees adjusted to each other.

S/P: Suppression pool RCIC: Reactor isolation cooling system In this state, after the reactor is separated from the adjacent reactor, when a low reactor water level signal is issued, the RCIC turbine 5 activates the first reactor water level. Second R
The CIC pumps 3a and 3b are driven, and cooling water is automatically sent from the condensate storage tank 1 to the first RCIC pump 3a side through the first cooling water supply line having the first electric valve 14a. The cooling water is branched through the bypass line 12 to the second RCIC pump 3b. Then, the cooling water is pumped from the first and second RCIC pumps 3a and 3b to the first and second RCIC pumps 3a and 3b. A third valve having a second flow regulating valve 7,8. The cooling water is force-fed to the reactor 4 through the fourth cooling water supply line, and a rated flow rate of cooling water is ensured within the reactor 4. Further, cooling water is supplied to the lubricating oil cooler 6 through a cooling water supply line branched from the third cooling water supply line.

Next, when the water level in the suppression pool 2 rises and the upper limit of the usage range is detected by the water level gauge 9, the detection signal is sent to the controller 11. Therefore, as shown in the table above and FIG.
The first electric valve 14b is opened and the first electric valve 14a is closed to switch the cooling water source from the condensate storage tank 1 to the suppression pool 2. In this operation mode, the second motor-operated valve 14b is removed from the suppression pool 2.
The cooling water is sent to the second RCIC pump 3b through the cooling water supply line, and the cooling water is branched to the first RCIC pump 3a through the bypass line 12.

Thereafter, the cooling water is supplied to the first. Second RCIC pump 3a
, 3b to the third. It is force-fed to the nuclear reactor 4 through the fourth cooling water supply line, and is also supplied to the lubricating oil cooler 6 through a cooling water supply line branched from the third cooling water supply line.

During this time, the water temperature at the cooling water inlet side of the lubricating oil cooler 6 is detected by the thermometer 10, and when the water temperature reaches the upper limit of the cooling water usage range, the controller 11 operates as shown in the table above and FIG. , the first and second electric valves 14a,
14b is also opened. Further, the bypass valve 13 is operated to close. Thereby, the water source of the cooling water is switched to both the condensate storage tank 1 and the suppression pool 2. As a result, the low temperature cooling water sent from the condensate storage tank 1 is transferred from the first cooling water supply line to the first RCIC pump 3.
a → The reactor 4 and the lubricating oil cooler 6 are supplied via the third cooling water supply line, and the cooling water sent from the suppression pool 2 is routed through the second cooling water supply line → the second RCIC pump 3b → the fourth The cooling water is supplied to the reactor 4 through the cooling water supply line.

Therefore, only low-temperature cooling water is supplied to the lubricating oil cooler 6 from the condensate storage tank 1. Mixed water from the condensate storage tank 1 and the suppression pool 2 is supplied to the reactor 4, as shown in FIG. 7, in order to suppress the rise in the suppression pool water level.

The relationship between the first and second flow rate regulating valves 7 and 8 is adjusted.

While keeping the flow rate to the reactor 4 constant, the first flow rate regulating valve 7 is controlled in the closing direction, and the second flow rate regulating valve 8 is controlled in the opening direction. As a result, compared to the prior art, the total amount of cooling water supplied from the condensate storage tank 1 is small, and the total amount of cooling water supplied from the suppression pool 2 is relatively large. Thereby, the margin of spatial volume of the suppression chamber can be increased.

Further, in this embodiment, as shown in FIG. 7, a control range is set during operation after switching the water source based on the water temperature on the cooling water inlet side of the lubricating oil cooler 6, and this control range is stored in the controller 11. Then, the controller 11 keeps the amount of cooling water to the reactor 4 constant and reduces the amount of cooling water from the condensate storage tank l as much as possible so that the cooling water from the suppression pool 2 is mainly supplied to the reactor 4. 1st. The opening degrees of the second flow rate regulating valves 7 and 8 are adjusted. That is, when the water temperature on the cooling water inlet side of the lubricating oil cooler 6 reaches the upper limit of the control range, the opening degree of the first flow rate regulating valve 7 is decreased, and the opening degree of the second flow rate regulating valve 8 is decreased. Enlarge.

As a result, the temperature of the cooling water supplied to the lubricating oil cooler 6 can be maintained at an appropriate level, and the space capacity margin of the suppression chamber can be further increased.

Furthermore, although each embodiment has been described with reference to the lubricating oil cooler 6 as an auxiliary machine that requires cooling water, the present invention is not limited to this and can be applied to any auxiliary machine that requires cooling water.

Further, the thermometer 10 is preferably provided as close as possible to the cooling water inlet of the auxiliary equipment, but it may also be provided on the discharge side of the RCIC pump 3 or the first RCIC pump 3a.

[Effects of the Invention] According to the invention described in claim 1 of the present invention described above, a water level gauge for detecting the upper limit of the usage range of the suppression pool and a cooling water inlet side of an auxiliary machine that requires cooling water are installed. A thermometer that detects water temperature and a controller are provided, and when the water level of the suppression pool rises and reaches the upper limit of the usage range of the suppression pool, the water level meter detects this.

Based on the detection signal, the controller opens the second flow rate regulating valve installed in the second cooling water supply line connected to the suppression pool, and the second flow rate adjustment valve installed in the first cooling water supply line connected to the condensate storage tank is opened. The first flow rate adjustment valve was closed, the cooling water source was switched from the condensate storage tank to the suppression pool, and the water temperature at the cooling water inlet side of the auxiliary equipment reached the upper limit of the cooling water usage range. At this time, the controller controls the first temperature based on the water temperature detected by the thermometer. The opening degree of the second flow rate regulating valve is also controlled to switch the cooling water source to both the condensate storage tank and the suppression pool, which has the effect of automatically switching the cooling water source. . In addition, when the water temperature on the cooling water inlet side of the auxiliary equipment rises, both the condensate storage tank and the suppression pool are used as cooling water sources, so the cooling water sent from the condensate storage tank is Since low-temperature cooling water can be supplied to the auxiliary equipment and the total amount of cooling water supplied from the suppression pool can be increased, the space volume margin of the suppression chamber can be increased.

Further, according to the invention as claimed in claim 2 of the present invention, the first. A second RCIC pump is provided, a first cooling water supply line having a first electric valve is connected between the condensate storage tank and the first RCIC pump, and a first cooling water supply line having a first electric valve is connected between the suppression pool and the second RCIC pump. .

A second cooling water supply line having a second electric valve connects the first RCIC pump to the reactor and auxiliary equipment, a third cooling water supply line connects the first RCIC pump to the reactor and auxiliary equipment, and the second RCIC pump and the reactor A fourth cooling water supply line connects between the first and second cooling water supply lines. Second
1 in the cooling water supply line. Connect the suction side of the second RCIC pump with a bypass line and bypass valve, install a water level gauge in the suppression pool, install a thermometer on the cooling water inlet side of the auxiliary equipment, and install a controller.

When the water level of the suppression boolean reaches the upper limit of the usage range, this is detected by the water level meter.

The detection signal is taken into the controller, which operates the second electric valve to open and the first electric valve to close, switches the cooling water source from the condensate storage tank to the suppression pool, and uses the thermometer to The water temperature on the cooling water inlet side of the auxiliary equipment is detected, and when the water temperature reaches the upper limit of the cooling water usage range, the controller controls the first. By opening the second electric valve and closing the bypass valve, the system switches to use both the condensate storage tank and the suppression pool as the cooling water source.
This has the effect of automatically switching the cooling water source. Furthermore, when the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the cooling water usage range, the cooling water source is switched to both the condensate storage tank and the suppression pool. In addition to being able to supply low-temperature cooling water to the auxiliary equipment using the cooling water sent from the tank, we also designed the following measures to supply a large amount of cooling water to the reactor from the suppression pool. Since the opening degree of the second flow rate regulating valve is adjusted, the total amount of cooling water from the suppression pool can be increased, which has the effect of increasing the margin of spatial volume of the suppression chamber.

According to the third aspect of the present invention, the first. a second flow rate regulating valve, a first. In the open mode of the second electric valve and the bypass valve, the controller controls the first electric valve so that the water temperature on the cooling water inlet side of the auxiliary equipment falls within a predetermined control range. The opening degree of the second flow rate regulating valve, the first. Since the opening and closing of the second electric valve and the bypass valve are adjusted, cooling water at an appropriate temperature is supplied to the auxiliary equipment, and the amount of cooling water from the suppression pool is lower than the total amount of cooling water from the cooling water source. This can be controlled by the controller so as to increase the total amount of , which has the effect of increasing the amount of operation required by the operator.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the present invention,
Figure 1 is a system diagram of the reactor isolation cooling system. Figure 2 is a flowchart of water source switching control, and Figure 3 is the relationship between the elapsed time of the reactor isolation timing, the flow rate of cooling water from the condensate storage tank, and the total amount of cooling water sent from the condensate storage tank. Figure 4 is a diagram showing the relationship between the elapsed time of the reactor isolation timing, the flow rate of cooling water sent from the suppression pool, and the total amount of cooling water sent from the suppression pool, and Figure 5 is a diagram showing the relationship between the elapsed time of the reactor isolation timing, the flow rate of cooling water sent from the suppression pool, and Figure 5 Figures 6 and 7, which show the relationship between the water temperature on the cooling water inlet side of the lubricating oil cooler and the control range, show other embodiments of the present invention.
The figure is a system diagram of the reactor isolation cooling system, and FIG. 7 is a flowchart of water source switching control. Figures 8 to 13 show the prior art, and Figure 8 is a system diagram of the reactor isolation cooling system, which draws cooling water from the condensate storage tank in response to a standby state and a low reactor water level signal. FIG. 9 is a diagram showing a state in which cooling water is being supplied from the suppression pool 6 when the water source is switched when the water level of the suppression pool reaches the rated point.
Figure 10 is an explanatory diagram of control when switching the cooling water source between the condensate storage tank and the suppression pool;
The figure shows the relationship between the elapsed time of the reactor isolation timer and the temperature of the suppression boule water, and Figure 12 shows the elapsed time of the reactor isolation timer and the flow rate of cooling water from the condensate storage tank.
FIG. 13 is a diagram showing the relationship between the total amount of cooling water and the elapsed time of the reactor isolation timing, the flow rate of cooling water from the suppression pool, and the water level of the suppression pool. 1... Condensate storage tank that is the first water source, 2... Suppression pool that is the second water source, 3... RCI
C pump, 4... Nuclear reactor, 5... RCIC turbine, 6... Lubricating oil cooler which is an auxiliary machine that requires cooling water. 7.8...1st. 2nd flow rate adjustment valve, 9... Water level gauge, 10... Thermometer that detects water temperature, 11... Controller, 3a, 3b - 1st. a second RCIC pump,
12...Bypass line, 13...Bypass valve,
14a, 14b...first degree second flow rate regulating valve, 15
...Manual switch, 16...Main steam relief safety valve. Agent Patent Attorney Tadashi Akimoto Actual Figure 1 White - F? CIC claw pump 6-Section oil cooler 11-Controller Fig. 2 WO: Wipe 7 out Fig. 3 Figure 5 original error of 4 houses, negative 1 name, 0 (simplified history of figure 6 1... Kansui-〇general? tan 7 4... ring-hi-kaketo
11.-Controller 2--Sable fly now embool
5.--FICIC tarp) 12.-Pi/gusline 3.--Nippon CIC7n'nd 6.Gi slide cooler 13-biha's loaf 117 Figure WO: Wipe 7 out Figure 8 3.・l:lc IC claw pump 6-・-! A
f oil gula 15...Mata Isoke No. 91〈3...F? CIC bow 7f' 6・-5MshiT
Oil 7-Ra 15...-Mugravity Mataka Figure 10 [Phase]: OR condition? ! ! , 11th shield, 12th Saki Seki No. 1 of the 1st branch of Yoshitakaga Ajisaki, 5th illustration - 5 - Roka Koi Gin Boku Mesakikaku

Claims (1)

[Scope of Claims] 1. A condensate storage tank that is a first water source, a suppression pool that is a second water source, and a reactor isolation cooling system pump are provided, and from the condensate storage tank to the first The first pump sends cooling water to the reactor isolation cooling system pump through the flow rate adjustment valve.
and a second cooling water supply line that sends cooling water from the suppression pool to the reactor isolation cooling system pump via a second flow rate regulating valve, and the reactor isolation cooling system pump In the reactor isolation cooling system, which is provided with a third cooling water supply line that pumps cooling water from the reactor to the auxiliary equipment, a water level gauge is provided to detect the upper limit of the usage range of the suppression pool, A thermometer is provided to detect the water temperature on the cooling water inlet side of the suppression pool, and when the detection signals are received from the water level gauge and the thermometer, and the water level of the suppression pool reaches the upper limit of the usage range, a second flow rate regulating valve is installed. When the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the usage range, the controller that controls the opening of the first and second flow regulating valves is operated. A nuclear reactor isolation cooling system characterized by the installation of this system. 2. A condensate storage tank that is a first water source, a suppression pool that is a second water source, and first and second reactor isolation cooling system pumps are provided, and a a first cooling water supply line that sends cooling water to a first reactor isolation cooling system pump via an electric valve; and a second cooling water supply line from the suppression pool to a second reactor isolation cooling system pump via a second electric valve. a second cooling water supply line that sends cooling water to the reactor, and a third cooling water that pumps cooling water from the first reactor isolation cooling system pump to the reactor and auxiliary equipment via the first flow rate adjustment valve. a fourth cooling water supply line that pumps cooling water from the second reactor isolation cooling system pump to the reactor via the second regulating valve; and the first and second reactor isolation cooling system pumps. A bypass line and a bypass valve connecting the first and second cooling water supply lines are provided on the suction side of the cooling system pump, a water level gauge is provided to detect the upper limit of the usage range of the suppression pool, and a water level gauge is provided to detect the upper limit of the usage range of the suppression pool. A thermometer is installed to detect the water temperature on the cooling water inlet side, and when the detection signals are received from the water level gauge and the thermometer, and the water level of the suppression pool reaches the upper limit of the usage range, the second electric valve is opened. , the first electric valve is closed, and when the water temperature on the cooling water inlet side of the auxiliary equipment reaches the upper limit of the usage range, the first and second electric valves are both opened and the bypass valve is closed. And, first,
A nuclear reactor isolation cooling system, characterized in that a controller for controlling the opening degree of a second flow rate regulating valve is installed. 3. In the open mode of the first and second flow rate adjustment valves, the first and second electric valves, and the bypass valve, so that the water temperature on the cooling water inlet side of the auxiliary equipment falls within a predetermined control range, The reactor isolation cooling system according to claim 1 or 2, wherein the controller adjusts the opening degrees of the first and second flow rate regulating valves, the opening and closing of the first and second electric valves, and the bypass valve. .