JPH01245194A - At-reactor isolation cooler - Google Patents

Abstract

PURPOSE:To enhance the reliability of the at-reactor isolation cooler so that the stable operation is assured by cooling and supplying the branched cooling water which is branched from the discharge side of an at-reactor isolation cooling pump and cools the lubricating oil for apparatus at the time of reactor isolation. CONSTITUTION:This device has the at-reactor isolation cooling pump 2 which injects the cooling water stored in a condensate storage tank 4 or a pressure control pool 5 to a reactor pressure vessel 1 at the time of the reactor isolation to supply the branched cooling water branched from the discharge side of the pump 2 to a lubricating oil cooler 6, thereby cooling the lubricating oil for apparatus. The radioactive steam discharged from the apparatus is condensed by the branched cooling water in a condenser 7. The branched cooling water supplied to the lubricating oil cooler 6 and the condenser 7 is cooled by a branched cooling water cooler 18 to which a cooling medium is supplied from a cooling medium supply device 19. The branched cooling water supplied to the lubricating oil cooler 6 is sufficiently cooled by the branched cooling water cooler 18 and, therefore, the temp. of the lubricating oil is maintained at a low temp. even if the temp. of the stored cooling water rises at the time of the reactor isolation by a loss of coolant.

Description

[Detailed Description of the Invention] (Objective of the Invention) (Industrial Application Field) The present invention relates to a nuclear reactor isolation cooling system, and in particular, even when the degree of cold Nj water lag in the system increases during an accident. This invention relates to a nuclear reactor isolation cooling system that suppresses the temperature of lubricating oil to a low level and safely continues equipment operation.

(Prior art) Boiling water reactors are equipped with a reactor isolation cooling system that supplies cooling water to the reactor in order to cool the reactor core and maintain the reactor water level when the reactor is isolated due to loss of 1 Jl of cold water. has been done.

Conventional reactor isolation IJ1 equipment generally supplies cold fJI water to the reactor pressure vessel 1 during reactor isolation, as shown in the system diagram in Figure 2. The Jl system pump 2, the turbine 3 that drives the isolated cooling system pump 2, the condensate storage tank 4 and pressure suppression boule 5 that store condensate or pool water that becomes cooling water, and the isolated cooling system pump 2. An F4 oil cooler 141 cools lubricating oil for equipment such as turbines and pumps using branched cooling water branched from the discharge side, and a barometric cooler that condenses radioactive steam discharged from the glands of the equipment. It is composed of a condenser 7 such as a condenser, piping connecting the above-mentioned devices, valves installed in the piping, and a measurement control device (not shown).

The suction pipe M8 connecting the condensate storage tank 4 and the pressure suppression pool 5 with the isolated cooling system pump 2 includes electric valves 9a and 9.
b and check valves 10a, 10b are provided.

Further, the discharge side of the isolated cooling system pump 2 is connected to the reactor pressure vessel 1 through an injection pipe 11.

Further, a branch cooling water pipe 12 is provided branching from the injection pipe 11, and this branch cooling water pipe 12 is connected to the r4 oil cooling W unit 6a.
, 5b to the condenser 7.

Roughly speaking, a main steam supply pipe 13 for supplying driving steam is connected to the inlet side of the turbine 3, while an exhaust pipe 14 connected to the pressure suppression boule 5 is provided to the outlet side.

During reactor isolation, steam is supplied to the turbine 3 via the main steam supply pipe 13 in response to a reactor water level low signal, and the isolation cooling system pump 2 is automatically started. The discharged cooling water passes through the injection pipe 11 and is supplied to the reactor pressure vessel 1.

Furthermore, radioactive steam discharged from the bearings, glands, etc. of equipment such as the turbine 3 passes through the leakage steam pipe 15 and is introduced into the condenser 7. As the condenser 7, for example, a barometric condenser is used. The radioactive steam is introduced into the condenser 7 whose pressure is reduced by the vacuum pump 16, where it is condensed by contacting the low temperature branch cooling water supplied from the branch cooling water pipe 12. The condensed water is
The water is returned to the suction side of the isolated cooling system pump 2 by the condensate pump 17 .

On the other hand, the branched cooling water passes through the branched cooling water pipe 12 branched from the discharge side of the isolated cooling system pump 2, and the branched cooling water flows into the lubricating oil cooler 5.
a, 6b. The lubricating oil coolers 6a and 6b enable stable operation of the equipment by cooling high-temperature lubricating oil discharged from equipment such as pumps and turbines.

The reactor is cooled by executing such isolation cooling mode operation.

(Problem to be solved by the invention) However, recently, in order to further improve the safety of nuclear reactor operation, the reactor isolation N1 equipment not only performs the conventional cooling mode operation at every M hour, but also performs emergency As a component of a core cooling system, there is a strong demand for such a system to also have the ability to perform accident mode operation to cool the core in the event of a loss of coolant accident.

That is, there is a need for a reactor isolation time logic W device that operates simultaneously with the other high pressure core spray devices, low pressure water injection device J3, and automatic depressurization installation that make up the emergency core cooling system, and efficiently cools the core.

In order to meet the above requirements, it is necessary to consider countermeasures when the operating temperature of the isolated cooling system pump increases. That is, it is necessary to take into account the rise in water temperature in the pressure suppression pool in J3 in the event of a cold member loss accident, and in that case, the operating temperature conditions will be stricter than in the past.

As a result, if the operation continues in the accident operation mode, the lubricating oil that had been prevented from circulating in the isolated cooling system pump and turbine bearings will not be sufficiently cooled in the lubricating oil cooler, and the lubricating oil temperature will drop to the conventional allowable value. There is a risk that the amount of water exceeds the amount of water and may interfere with the operation of component equipment such as pumps and turbines.

In addition, the vapor pressure of the condensed water in the condenser may rise, making it difficult to condense radioactive steam, or the effective suction head of the condensate pump (
N P S H) decreases, causing xevitation, which may damage the condensate pump and further impede the operation of the entire turbine gland seal system.

The present invention has been made in order to solve the above problems, and even in the event of a loss of coolant accident, it suppresses the temperature rise of the cooling water supplied to the rII oil cooling system and the condenser, and provides an emergency core cooling system. It is an object of the present invention to provide a reactor isolation cooling system that can operate together with the nuclear reactor, has high reliability, and enables stable operation.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the reactor isolation dumping device according to the present invention is designed to transfer cooling water stored in a condensate storage tank or a pressure suppression pool to nuclear reactors during reactor isolation. A lubricating oil cooler cools equipment lubricating oil using branched cooling water branched from the discharge side of the isolated JI system pump, which is injected into the reactor pressure vessel, and the discharge side of the isolated JI system pump. a condenser for condensing the radioactive vapor by the branch cooling 7.1 water;
Branch cooling fi1 supplied to the above lubricating oil cooler and condenser
It is characterized by comprising a branch cooling water cooler that cools water, and a cooling medium supply device that supplies cold 2Jl medium to the branch cooling water cooler.

Further, the cooling medium supply device is preferably provided with a temperature detector that detects the temperature of the branched cooling water and an opening/opening valve that opens and closes the pipe line that supplies the cooling medium.

(Function) Reactor separation i with the above configuration! ! According to II Jiron 7i11 &Oki, even if the temperature of the stored cooling water rises during reactor isolation due to loss of cooling water, the branch cooling II water supplied to the lubricating oil cooler will continue to be used for branch cooling. Since the lubricating oil is sufficiently cooled by the water cooler, the temperature of the lubricating oil is always maintained at a low temperature.

Therefore, the function of IJI system pumps, turbines, and other devices is guaranteed at the interval + m required for the operation of the device, and the reactor isolation cooling device can always be operated with high reliability and in a stable state.

(Embodiment) Next, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a system diagram showing an embodiment of the reactor isolation cooling system according to the present invention. Note that the same elements as those in the conventional example shown in FIG. 2 are given the same reference numerals, and detailed explanation thereof will be omitted.

The reactor isolation system FJ device according to this embodiment is an isolation system 11 system that injects cold water stored in the condensate storage tank 4 or the pressure suppression boule 5 into the reactor pressure vessel 1 during reactor isolation. Pump 2 and isolation cooling system pump 2') Two lubricating oil coolers 5a for cooling equipment and 121 lubricating oil by branched cooling water branched from the discharge side h.

6b, a condenser 7 such as a barometric condenser that condenses the radioactive steam discharged from the equipment with the branch cold RN water, and a branch cooling water that is sent to the lubricating oil cooling NJ unit 6 and the condenser 7. The branch cooling water cooler 18 is configured to include a branch cooling water cooler 18 and a cooling medium supply device 19 that supplies cooling medium to the branch cooling water cooler 18.

The cooling medium supply device 19 also includes a temperature detector 20 that detects the temperature of the branch cooling water, and an electric on-off valve 21 that opens and closes the pipe line 22 that supplies the cooling medium, so that the temperature of the branch cooling water reaches a predetermined value. If the temperature exceeds the
The configuration is such that an open signal is output.

Here, the cooling medium supply device 19 does not use the cooling water stored in the condensate storage tank 4 or the pressure suppression pool 5, but instead uses cooling water from another system, such as cooling water taken from the auxiliary equipment cooling device, for cooling. used as a medium.

When a loss of coolant accident occurs and an abnormal signal indicating low reactor water level or high reactor containment vessel pressure is issued, the turbine 3 is automatically started. Cooling water is injected into the reactor pressure vessel 1 by the isolation cooling system pump 2 driven by the turbine 3 .

While the injection work into the reactor pressure vessel 1 is proceeding, the temperature of the cooling water stored in the pressure suppression boule 5 becomes -L'f1-, and T
When the lubricating oil cooling function in the A lubricating oil coolers 5a and 5b deteriorates, an open signal is sent to the electric on-off valve 21 from the temperature detector 20 that has detected the limit W temperature of the branched cooling water.

By opening the on-off valve 21, the cooling medium is supplied from the auxiliary cooling fill device as the cooling medium supply device 19 to the branch cooling 114 water cooler 18. After the branch cooling water cooler 18 sufficiently cools the branch cooling water, the water is passed to the lubricating oil coolers 6a and 5b. The cooled branch cooling water is sent to the lubricating oil cooler 5.
In a and 6b, the lubricating oil for the pump and turbine bearings is cooled 1. After irradiation, it is fed to the condenser 7, and is further brought into contact with radioactive steam from a turbine or the like to condense the radioactive steam.

The reactor isolation cooling system according to this embodiment has a branch cooling water cooler 18 that performs heat exchange using a cooling medium supplied from outside the system added to the conventional system, so that it is possible to avoid problems in the event of a loss of coolant accident. Even when the temperature of the branch cooling water increases, the lubrication function of the component equipment is maintained.

In other words, since the branch cooling water sufficiently cooled by the branch cooling water cooler 18 is passed through the lubricating oil coolers 6a and 6b, the temperature of the lubricating oil is always kept low, and the components such as pumps and turbines are always operated smoothly. can be operated in stable conditions.

In addition, since the low-temperature branch cooling 74 + water is supplied to the condenser 7, the steam pressure in the condenser 7 does not increase, and loss 48 due to cavitation of the condensate pump 17 is prevented. The radioactive vapor introduced into the condenser 7 from other sources is also efficiently condensed, and operation can be continued with the metal bodies in the system in a stable state.

The design standard for conventional reactor isolation cooling systems was to use a DC power source as the power source for the electrical equipment required to operate the system. By having this power supply, in the event of a loss of coolant accident, it is possible to share the AC power supply for other emergency core cooling systems, which also contributes to reducing the manufacturing cost of the cooling equipment as a whole.

(Effects of the Invention) As explained above, according to the reactor isolation cooling system according to the present invention, even when the humidity of the stored cooling water reaches its upper limit during the reactor isolation due to loss of cooling water, the lubrication Oil cooling! Since the branch cooling water supplied to the Jl unit is sufficiently cooled by the cooling medium supplied from outside the system in the branch cooling water cooler, the temperature of the lubricating oil is always maintained at a low temperature.

Therefore, the lubrication function of equipment such as the isolation cooling system pump and turbine necessary for the operation of the equipment is guaranteed, and the reactor isolation time is guaranteed! It becomes possible to operate the I device in a highly reliable and stable state at all times, and the safety of the atomic coupler can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an embodiment of the reactor isolation cooling system according to the present invention, and Fig. 2 is a system diagram showing an example of the configuration of a conventional reactor isolation system/Jl device.1.・Reactor pressure vessel, 2... Reactor isolation N1 system pump, 3... Turbine, 4... Condensate storage tank, 5... Pressure suppression pool, 6, 6a, 6b... Lubricating oil cooler, 7°°° condenser, 8... Suction piping, 9a, 9b... Electric valve, ioa
, 10b... Check valve, 11... Injection piping, 12...
・Branch cooling water piping, 13...↑Steam supply piping, 14・
...Exhaust piping, 15...Leaking steam pipe, 16...Vacuum pump, 17...Condensate pump, 18...Branch cooling water cooler, 19...Cooling medium supply device, 2o... ...Temperature detector, 21...Opening/closing valve, 22...Pipe line. Representative Patent Attorney Noriyuki Chika1ii1
Takeshi Komaru Diagram 1

Claims (1)

[Claims] 1. An isolation cooling system pump that injects cooling water stored in a condensate storage tank or a pressure suppression pool into a reactor pressure vessel during reactor isolation, and from the discharge side of the isolation cooling system pump. A lubricating oil cooler that cools lubricating oil for equipment using branched cooling water; a condenser that condenses radioactive steam discharged from the equipment using the branched cooling water; and the lubricating oil cooler and condensation. What is claimed is: 1. A cooling system for reactor isolation, comprising: a branch cooling water cooler that cools branch cooling water supplied to the reactor; and a cooling medium supply device that supplies a cooling medium to the branch cooling water cooler. 2. The cooling medium supply device is equipped with a temperature detector that detects the temperature of the branch cooling water and an on-off valve that opens and closes the pipe that supplies the cooling medium, and when the temperature of the branch cooling water exceeds a predetermined value, the temperature 2. The reactor isolation cooling system according to claim 1, wherein the detector outputs an open signal to the on-off valve.