JPH11326577A - Reactor isolation cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor isolation cooling device suppressing the increase of oxygen concentration due to inflow of air into the pressure suppression room in a reactor containment during the operation of reactor isolation cooling device. SOLUTION: Reactor isolation cooling device is provided with a turbine ground seal device 21 introducing leaked steam and non-condensible gas form the round part of a turbine 2 driving a water injection pump 9 of the reactor isolation cooling system into a barometric condenser 12 and exhausting from a vacuum tank 13 to a pressure suppression room 4 via a vacuum pump 16. The vacuum tank 13 is provided with a pressure gauge and the exhaust pipe 17a of the vacuum pump 16 is provided with a pressure control valve 22 so that the flowrate of the vacuum pump 16 is controlled by operating the pressure control valve 22 to keep the pressure in the vacuum tank 13 not lower than the operation pressure of the vacuum breaker valve 18 based on the measured result of the pressure gauge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor isolation cooling system for cooling a reactor core when the reactor is isolated.

[0002]

2. Description of the Related Art In a reactor isolation cooling system, make-up water is injected into a reactor pressure vessel in order to prevent insufficient cooling of a stopped core when a water supply loss occurs in a reactor water supply system. It is installed to cool the reactor core.

[0003] A steam turbine drive pump utilizing residual steam in the reactor is used as a water injection pump for injecting make-up water into the reactor isolation cooling device. The turbine of the water injection pump has a turbine gland sealing device. Is provided. This turbine gland sealing device is for preventing radioactive steam leaking from each gland from being discharged into the turbine pump chamber.

As shown in the configuration diagram of FIG. 5, steam is transferred from a turbine steam pipe 1 branched from a main steam pipe (not shown) connected to a reactor pressure vessel (not shown) to a turbine 2 of a cooling system at the time of reactor isolation. This steam is exhausted into the liquid phase section 5 of the pressure control chamber 4 via the exhaust pipe 3 after working in the turbine 2.

The turbine steam pipe 1 connected to the turbine 2 has valves 6, 7, and 8 interposed therein. Rotational force of the turbine 2, which rotates by receiving steam from the turbine steam pipe 1, is transmitted to a water injection pump 9 as a pump driving force, and the water injection pump 9 transfers cooling water from a water source to a reactor pressure vessel.

[0006] Steam and non-condensable gas leaking from each gland of the turbine 2 in the reactor isolation cooling system are introduced into a turbine gland sealing device 11 through respective pipes 10, and the leaked steam is barometrically Water is condensed in the condenser 12 by spray water.

The condensate and the non-condensable gas flow into the vacuum tank 13, and the condensate 14 is sent out by the condensate pump 15 to the suction port of the injection pump 9 of the reactor isolation cooling system. Further, the non-condensable gas is transferred to the liquid phase portion 5 of the pressure suppression chamber 4 by the vacuum pump 16, but the suction pipe 17 b of the vacuum pump 16 prevents the pressure in the vacuum tank 13 from excessively decreasing. Vacuum break valve 1 to prevent
8 are installed. When the pressure in the vacuum tank 13 falls below a predetermined set pressure, the vacuum break valve 18 opens to send the air in the room where the turbine 2 is installed to the pressure suppression chamber 4 by the vacuum pump 16.

At this time, since the air in the turbine chamber contains oxygen, there is a possibility that the oxygen concentration in the gas phase portion 19 of the pressure suppression chamber 4 may increase during operation of the reactor isolation cooling system. On the other hand, during normal operation of the containment vessel, the dry well and the inside of the reactor pressure suppression chamber 4 are inerted with nitrogen. This is to keep the oxygen concentration in the reactor containment vessel at a specified value, so that the time until the recombination reaction between hydrogen and oxygen is possible after the loss of coolant accident is sufficiently long. is there.

As this means, an inert gas system is installed in the plant.

[0010]

If the pressure in the vacuum tank 13 decreases excessively during the operation of the reactor isolation cooling system, the vacuum break valve 18 opens to evacuate the oxygen-containing air in the turbine chamber. While being introduced into the tank 13,
The air in the vacuum tank 13 is sent out by the vacuum pump 16 into the liquid phase section 5 of the pressure suppression chamber 4.

As a result, the oxygen concentration in the pressure suppression chamber 4 increases, so that it is necessary to operate the inert gas system to reduce the oxygen concentration.

As described above, when the reactor isolation cooling system is operated, air containing oxygen flows into the pressure suppression chamber 4 in the containment vessel.

Such an inflow of air into the pressure suppression chamber 4 is not preferable from the viewpoint of maintaining the interior of the containment vessel in an inert atmosphere, and becomes inactive each time the cooling system is operated when the reactor is isolated. Operating a gas system is not preferred for nuclear power plant operation. A similar situation may occur when the test operation of the reactor isolation cooling system is periodically performed during the normal operation of the nuclear power plant.

An object of the present invention is to control the vacuum tank pressure during the operation of the cooling system at the time of reactor isolation to prevent the operation of the vacuum break valve and suppress the increase in the oxygen concentration in the pressure suppression chamber. To provide a reactor isolation cooling system.

[0015]

A first means of achieving the object of the present invention is to reduce the leakage of steam and non-condensable gas from the gland of a turbine that drives a water injection pump of a cooling system during isolation of a reactor. A reactor isolation cooling system including a turbine gland seal device that is introduced into a metric condenser and discharges the non-condensable gas from a vacuum tank equipped with a vacuum release valve to a pressure control chamber via a vacuum pump,
A pressure gauge is provided in the vacuum tank, and a pressure adjustment valve of the vacuum tank is provided in the exhaust pipe of the vacuum pump, and the opening degree of the pressure adjustment valve is set based on the measurement result by the pressure gauge. A reactor isolation cooling device comprising means for controlling the vacuum tank pressure to prevent the pressure from dropping to the operating pressure of the vacuum break valve, wherein the reactor is isolated when the reactor is stopped. Then, when the cooling system at the time of reactor isolation operates and the vacuum pump operates, the opening of the adjustment valve on the vacuum pump exhaust side is controlled by the pressure gauge provided in the vacuum tank, whereby the pressure in the vacuum tank becomes excessive. To prevent the vacuum break valve from opening, and therefore, when the reactor isolation cooling device is operating, the flow of air into the pressure suppression chamber is small, and the acid inside the containment vessel is reduced. Elevated levels are suppressed.

[0016] Similarly, the second means is to introduce a leaked steam and a non-condensable gas from a ground portion of a turbine for driving a water injection pump of a cooling system at the time of a reactor isolation into a barometric condenser to evacuate the non-condensable gas into a vacuum. In a reactor isolation cooling system having a turbine gland seal device for discharging a vacuum tank equipped with a release valve to a pressure control chamber via a vacuum pump, a pressure gauge is provided in the vacuum tank, and a pressure gauge is provided in an exhaust pipe of the vacuum pump. The bypass line to the vacuum tank,
A bypass valve is provided in each of the bypass lines, and the opening degree of the bypass valve is reduced based on the measurement result by the pressure gauge, and the vacuum tank pressure is reduced to the operating pressure of the vacuum break valve by activation of the vacuum pump. A cooling device at the time of reactor isolation characterized by comprising means for controlling so as to prevent, when the cooling device at the time of reactor isolation is activated and the vacuum pump is activated, a vacuum is provided by a pressure gauge provided in the vacuum tank. Controls the opening of the regulating valve provided in the piping as a bypass line connecting the pump discharge side and the vacuum tank, thereby preventing the pressure in the vacuum tank from excessively dropping and opening the vacuum break valve, During operation of the reactor isolation cooling device, the flow of air into the pressure suppression chamber is small, and an increase in the oxygen concentration in the containment vessel is suppressed.

[0017] Similarly, the third means is to introduce a leaked steam and a non-condensable gas from a gland of a turbine for driving a water injection pump of a cooling system at the time of a reactor isolation into a barometric condenser to evacuate the non-condensable gas into a vacuum. In a reactor isolation cooling system having a turbine gland seal device for discharging a vacuum tank equipped with a release valve to a pressure control chamber via a vacuum pump, a pressure gauge is provided in the vacuum tank, and the pressure gauge is provided in the vacuum pump. An inverter that controls the pump rotation speed based on the pressure measurement result to prevent the pressure in the vacuum tank from lowering to the operating pressure of the vacuum break valve by starting the vacuum pump. A pressure gauge installed in the vacuum tank when the reactor isolation cooling system operates and the vacuum pump operates. Therefore, the number of rotations of the vacuum pump is controlled, thereby preventing the pressure in the vacuum tank from excessively dropping and opening the vacuum break valve, and allowing the cooling system during the isolation of the reactor to operate to enter the pressure suppression chamber. And the increase of the oxygen concentration in the containment vessel is suppressed.

Similarly, the fourth means is to introduce the steam and the non-condensable gas leaked from the gland of the turbine for driving the water injection pump of the cooling system at the time of the reactor isolation into the barometric condenser to evacuate the non-condensable gas. In a reactor isolation cooling system equipped with a turbine gland seal device for discharging a vacuum tank equipped with a release valve to a pressure control chamber through a vacuum pump, a pressure gauge is provided in the vacuum tank, and an operating pressure of the vacuum release valve is provided. A reactor isolation cooling device comprising an ON / OFF control unit for operating or stopping the vacuum pump based on a measurement result of the pressure gauge so as to control a pressure of a vacuum tank below. Yes, when the reactor cooling system operates and the vacuum pump operates, the vacuum pump is turned on by the pressure gauge provided in the vacuum tank.
/ OFF control, thereby preventing the pressure in the vacuum tank from excessively lowering and opening the vacuum break valve, and preventing the inflow of air into the pressure suppression chamber during the operation of the reactor isolation cooling device. The increase in the oxygen concentration in the containment vessel is suppressed.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In the description, the same components as those in the above-described conventional technology are denoted by the same reference numerals, and detailed description is omitted.

First, in the first embodiment shown in FIG. 1, the leaked steam and the non-condensable gas from each gland of the turbine 2 of the cooling system at the time of the reactor isolation are supplied to the turbine gland seal via each pipe 10. It is introduced into the device 21.

The leaked steam is condensed by spray water in the barometric condenser 12, and the condensed water and the non-condensable gas flow into the vacuum tank 13. It is sent to the suction port of the water injection pump 9 of the device. The non-condensable gas is sent to the pressure suppression chamber 4 by the vacuum pump 16.

A pressure regulating valve 22 is provided in the exhaust pipe 17a of the vacuum pump 16, and the pressure regulating valve 22
A pressure gauge 20 is provided in the vacuum tank 13 in order to output a control signal.

Next, the operation of the above configuration will be described. Abnormal operation of the reactor occurred, the reactor was isolated,
When the cooling system at the time of reactor isolation operates and the vacuum pump 16 operates, the pressure of the vacuum tank 13 causes the vacuum pump 1 to operate.
6. Control the opening of the pressure regulating valve 22 of the exhaust pipe 17a.

Therefore, it is possible to prevent the pressure in the vacuum tank from excessively lowering and to operate the vacuum breaking valve 18, and the inside of the gas phase portion 19 of the pressure suppression chamber 4 during the operation of the reactor isolation cooling system is maintained. Since the flow of air is small, the oxygen concentration does not increase, and the inside of the pressure suppression chamber 4 can be easily maintained in an inert atmosphere.

In the second embodiment, as shown in the system configuration diagram of FIG. 2, the leakage steam and the non-condensable gas in each gland in the turbine 2 of the cooling system at the time of isolation of the reactor are supplied to each pipe 10
Is introduced into the turbine gland sealing device 25 through the

The leaked steam is supplied to the barometric condenser 12
The condensate and the non-condensable gas flow into the vacuum tank 13, and the condensate 14 is sent by the condensate pump 15 to the suction side of the injection pump 9 of the reactor isolation cooling system. Can be The non-condensable gas is supplied by a vacuum pump 1
It is sent to the suppression chamber 4 by 6.

The exhaust pipe 17a of the vacuum pump 16 is provided with a bypass line 23 to the vacuum tank and a bypass valve 24. A pressure gauge 20 is provided in the vacuum tank 13 to output a control signal to the bypass valve 24. It is.

Next, the operation of the above configuration will be described. Abnormal operation of the reactor occurred, the reactor was isolated,
When the reactor isolation cooling device operates and the vacuum pump 16 operates, the opening of the bypass valve 24 of the bypass line 23 is controlled by the pressure of the vacuum tank 13.

Therefore, it is possible to prevent the pressure in the vacuum tank from excessively lowering and to operate the vacuum break valve 18, and the inside of the gas phase portion 19 of the pressure suppression chamber 4 during the operation of the reactor isolation cooling system. Since the flow of air is small, the oxygen concentration does not increase, and the inside of the pressure suppression chamber 4 can be easily maintained in an inert atmosphere.

In the third embodiment, as shown in the system configuration diagram of FIG. 3, the leaked steam and the non-condensable gas from each gland of the turbine 2 of the cooling system at the time of isolation of the nuclear reactor pass through each pipe 10. The steam is introduced into the turbine gland sealing device 27 and the leaked steam is condensed by the spray water in the barometric condenser 12.

The condensed water and the non-condensable gas flow into a vacuum tank 13, and the condensed water 14 is sent out by a condensate pump 15 to a suction port of a water injection pump 9 of a cooling device at the time of reactor isolation. Further, the non-condensable gas is sent to the pressure suppression chamber 4 by the vacuum pump 16.

An inverter 26 for controlling the rotation speed of the vacuum pump 16 is provided, and a pressure gauge 20 is provided in the vacuum tank 13 to output a control signal to the inverter 26.

Next, the operation of the above configuration will be described. Abnormal operation of the reactor occurred, the reactor was isolated,
When the reactor isolation cooling system operates and the vacuum pump 16 operates, the pressure in the vacuum tank 13 causes the inverter 26 to operate.
Is changed to control the rotation speed of the vacuum pump 16.

Therefore, it is possible to prevent the pressure in the vacuum tank from excessively lowering and to operate the vacuum break valve 18, and the inside of the gas phase portion 19 of the pressure suppression chamber 4 during the operation of the reactor isolation cooling device is maintained. Since the flow of air is small, the oxygen concentration does not increase, and the inside of the pressure suppression chamber 4 can be easily maintained in an inert atmosphere.

In the fourth embodiment, as shown in the system configuration diagram of FIG. 4, leaked steam and non-condensable gas from each gland part of the turbine 2 of the cooling system at the time of nuclear reactor isolation pass through each pipe 10. The steam is introduced into the turbine gland seal device 29 and the leaked steam is condensed by the spray water in the barometric condenser 12.

The condensed water and the non-condensable gas flow into a vacuum tank 13, and the condensed water 14 is sent out by a condensate pump 15 to a suction port of a water injection pump 9 of a cooling device at the time of reactor isolation. Further, the non-condensable gas is sent to the pressure suppression chamber 4 by the vacuum pump 16.

A switch 28 for controlling the on / off of the vacuum pump 16 is provided, and a pressure gauge 20 is provided in the vacuum tank 13 to output a control signal to the switch 28. Next, the operation of the above configuration will be described. When an abnormality occurs in the operation of the reactor and the reactor is isolated, and the cooling system is operated when the reactor is isolated and the vacuum pump 16 is operated, the operation of the vacuum pump 16 is turned on / off by the pressure of the vacuum tank 13. I do.

Accordingly, it is possible to prevent the pressure in the vacuum tank from excessively decreasing and to operate the vacuum break valve 18, and the inside of the gas phase portion 19 of the pressure suppression chamber 4 during the operation of the reactor isolation cooling system is maintained. Since the flow of air is small, the oxygen concentration does not increase, and the inside of the pressure suppression chamber 4 can be easily maintained in an inert atmosphere.

[0039]

According to the first aspect of the present invention, the function of the cooling device at the time of reactor isolation is the same as that of the conventional cooling device. Even when the isolated cooling device is operated, the oxygen concentration in the suppression chamber does not increase. For this reason,
Since there is no need to operate the inert gas system to adjust the oxygen concentration in the pressure suppression chamber to a specified value, there is an effect of improving the safety of the reactor operation and reducing the burden on the operators.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, there is an effect that the controllability can be improved by controlling the circulation of the gas in the vacuum tank.

According to the invention of claim 3, in addition to the effect of the invention of claim 1, there is an effect that it is possible to prevent the failure of the vacuum tank pressure control due to the failure of the pressure regulating valve.

According to the invention of claim 4, in addition to the effect of the invention of claim 1, there is an effect that the reliability of the equipment is improved by simplifying the equipment most.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a reactor isolation cooling device according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram of a reactor isolation cooling system according to a second embodiment of the present invention.

FIG. 3 is a system configuration diagram of a reactor isolation cooling system according to a third embodiment of the present invention.

FIG. 4 is a system configuration diagram of a reactor isolation cooling system according to a fourth embodiment of the present invention.

FIG. 5 is a system configuration diagram of a conventional reactor isolation cooling system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Turbine steam pipe, 2 ... Turbine, 3 ... Exhaust pipe, 4 ...
Pressure suppression chamber, 5: liquid phase section, 6 to 8: valve, 9: water injection pump, 10: pipeline, 11, 21, 25, 27, 29: turbine gland sealing device, 12: barometric condenser, 13: vacuum Tank, 14: Condensate, 15: Condensate pump, 16: Vacuum pump, 17a: Exhaust pipe, 17b: Suction pipe, 18: Vacuum release valve, 19: Gas phase, 20: Pressure gauge, 22: Pressure control valve , 23 ... bypass line, 24 ...
Bypass valve, 26 ... inverter, 28 ... switch.

Claims (4)

[Claims] 1. A vacuum release valve for introducing steam leaking from a gland of a turbine and a non-condensable gas into a barometric condenser for driving a water injection pump of a cooling system at the time of isolation of a reactor into a barometric condenser. A reactor isolation cooling system having a turbine gland sealing device for discharging a vacuum tank from a vacuum tank to a pressure control chamber via a vacuum pump, comprising: a pressure gauge in the vacuum tank; and a vacuum tank pressure in an exhaust pipe of the vacuum pump. Adjusting valves are provided, respectively, so that the opening degree of the pressure adjusting valve based on the measurement result by the pressure gauge is prevented from lowering the vacuum tank pressure to the operating pressure of the vacuum breaking valve by activation of the vacuum pump. A cooling device at the time of nuclear reactor isolation, comprising: 2. A vacuum release valve for introducing a leaked steam and a non-condensable gas from a gland of a turbine for driving a water injection pump of a cooling system at the time of a reactor isolation into a barometric condenser to remove said non-condensable gas. A reactor with a turbine gland seal device for discharging a vacuum gland from the vacuum tank to a pressure control chamber via a vacuum pump, wherein a pressure gauge is provided on the vacuum tank, and a vacuum gauge is provided on an exhaust pipe of the vacuum pump to the vacuum tank. A bypass line is provided with a bypass valve in the bypass line, and the opening degree of the bypass valve is set based on the measurement result by the pressure gauge.By starting the vacuum pump, the vacuum tank pressure is reduced to the operating pressure of the vacuum break valve. A cooling device at the time of reactor isolation, comprising: means for controlling so as to prevent the cooling from occurring. 3. A non-condensable gas leaked from a gland of a turbine driving a water injection pump of a cooling system at the time of reactor isolation and a non-condensable gas are introduced into a barometric condenser, and the non-condensable gas is provided with a vacuum break valve. A reactor with a turbine gland seal device that discharges from a vacuum tank to a pressure control chamber via a vacuum pump, a pressure gauge is provided in the vacuum tank, and a pressure measurement result of the pressure gauge is provided in the vacuum pump. A reactor that controls a pump rotation speed based on the following so as to prevent the pressure of the vacuum tank from dropping to the operating pressure of the vacuum break valve by activation of the vacuum pump. Isolation cooling device. 4. A vacuum release valve for introducing a leaked steam and a non-condensable gas from a gland of a turbine for driving a water injection pump of a cooling system at the time of a reactor isolation into a barometric condenser to convert the non-condensable gas into a vacuum. A reactor with a turbine gland seal device for discharging a vacuum gland from a vacuum tank to a pressure control chamber via a vacuum pump. A reactor isolation cooling system comprising ON / OFF control means for operating or stopping the vacuum pump based on the measurement result of the pressure gauge so as to control the pressure of the reactor.