JP3149553B2 - Reactor equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear reactor, and more particularly to a nuclear reactor cooling equipment required in an accident.

[0002]

2. Description of the Related Art In a boiling water reactor, as a method of cooling a core in a reactor pressure vessel in the event of a loss of cooling water such as a pipe breakage accident, there is known a thermal nuclear power plant Vol. 39, No. 8 (1
988), there is an emergency core cooling system that does not use a dynamic device such as a pump. This is to simplify the system by applying a gas pressure to the water tank for cooling the core in advance and installing two systems of accumulator water injection systems that take a static method of injecting cooling water by the pressure difference from the reactor pressure vessel. It is intended.

As another static core cooling system, as described in JP-A-57-69289, the cooling water storage tank and the reactor pressure vessel are pressure-equalized, and the cooling water is supplied only by gravity. There is a gravity drop type water injection system that injects water into the reactor pressure vessel.

[0004] As a method for improving the reliability of a reactor having this gravity drop type water injection system, a water tank and a water tank are not provided with a communication passage for equalizing pressure in the reactor pressure vessel. A method of opening the reactor containment dry well is adopted.
In this case, a large-capacity decompression system is installed in the main steam system in order to equalize the pressure in the water storage tank and the reactor pressure vessel early and start water injection into the reactor pressure vessel in the event of a pipe breakage accident. The pressure inside the reactor pressure vessel is rapidly reduced.

[0005]

When dynamic equipment such as a pump is used as a method for cooling the core in a reactor pressure vessel at the time of a loss of cooling water such as a pipe breakage accident, there is a mechanically movable part. Malfunctions, such as failures and reduced output,
The prior art of a water injection system or a pressure accumulating water injection system using the above equalizing means has the advantage that the possibility is reduced.

However, when a pressure accumulating type water injection device is used,
Although it is possible to inject water at an early stage after an accident, even during normal operation, it is necessary to apply high-pressure gas pressure to the water tank to maintain the high-pressure state of the water tank. It must have a pressure-resistant structure that can withstand the added extremely high pressure.

For this reason, there is a problem that the water storage tank cannot be made large and a large amount of water cannot be secured, and water cannot be injected for a long time. If the water storage volume is increased, the economics of reactor production will decrease.

[0008] In the gravity drop type water injection device, the size of the water storage tank can be increased. However, in order to inject cooling water into the reactor pressure vessel at an early stage, the capacity of the pressure reducing system must be increased or the water storage capacity must be increased. The tank must be placed at a higher position than before to increase the hydrostatic head of the gravity drop type water injection device.

However, in the depressurizing process by the depressurizing system, a large amount of saturated cooling water is present in the reactor pressure vessel, and a large amount of boiling steam is generated. There is a possibility that the internal pressure does not easily decrease, the operation time of the gravity drop type water injection device is delayed, and a problem that the core cannot be sufficiently cooled may occur.

Further, when the installation position of the water storage tank is increased in order to increase the water injection and hydrostatic head, since the installation position is limited by the height of the reactor containment vessel, it is not possible to sufficiently increase the water injection and hydrostatic head. There is. Alternatively, if the height of the reactor containment vessel is increased to increase the location of the water storage tank,
Not only the containment vessel but also the height of the reactor building is increased, and there is a problem that the economical efficiency of reactor production is reduced.

In addition, once the water injection by the accumulator type water injection device and the gravity drop type water injection device is started, the whole amount is injected in a short time, and excess cooling water flows out of the reactor pressure vessel.

In order to effectively cool the core using a pressure accumulating type water injection device or a gravity drop type water injection device, it is necessary to inject a cooling water amount corresponding to the decay heat generated in the core. As the pressure in the reactor pressure vessel decreases with the passage of time, it is necessary to control the injection flow rate by reducing the injection head.

An object of the present invention is to make it possible to quickly inject water into a reactor pressure vessel of a gravity drop type water injection device in a reactor cooling facility while minimizing the size of storage means such as a reactor containment vessel as much as possible. The purpose is to do.

[0014]

The first means is based on a water level difference.
First means for converting the potential energy or water injection required heat energy added to the water during brute pressure of the gas phase, connected to the reactor core position via the valve gas pressure to the reactor pressure vessel by the means And a second means for applying the cooling water to a cooling water tank located at a higher position than the cooling water tank.

The second means is the first means, wherein a first cooling water tank located below a water level in the cooling water pool, a liquid phase portion of the cooling water pool, and the inside of the first cooling water tank. A first means having a first flow path communicating with the first cooling water tank, and a first means provided between a gas phase portion of the first cooling water tank and a second cooling water tank higher than the first cooling water tank. A nuclear reactor comprising: a second means having a communication passage; and a second flow passage connecting a liquid phase part in the second cooling water tank and the inside of the reactor pressure vessel via a valve. It is a cooling device. A third means is the reactor cooling apparatus according to the second means, wherein the first cooling water tank is provided with a third flow passage for communicating the cooling water with the inside of the reactor pressure vessel via a valve.

A fourth means is the reactor cooling apparatus according to the third means, wherein the second flow path and the third flow path are independent of each other.

The fifth means is the second means, wherein the communication passage between the first cooling water tank and the second cooling water tank is connected to the third cooling water tank provided with a height difference on the way. 4
A pressure increasing means having a fourth flow path communicating between the liquid phase portion of the third cooling water tank at a relatively high place and the inside of the fourth cooling water tank at a relatively low place in the cooling water tank; Is provided in series with the first cooling water tank and the second cooling water tank.

A sixth means is the fifth means, wherein the first cooling water tank is provided with a third flow path for communicating cooling water through a valve with the inside of the reactor pressure vessel, and the fourth cooling water tank is provided with a reactor pressure. A reactor cooling device, comprising: a fifth flow passage that communicates cooling water with the inside of a vessel via a valve.

A seventh means is the reactor cooling apparatus according to the sixth means, wherein the second flow path, the third flow path, and the fifth flow path are independent of each other.

Eighth means is the second or third means,
The cooling water pool has a structure in which the transition between the inside and outside is restricted in terms of pressure, and a system for applying a pressure generated in the reactor pressure vessel to the cooling water pool via a valve is provided. Furnace cooling device.

The ninth means is the second or third means,
The second cooling water tank is a reactor cooling device characterized in that a part of a cooling water pool is isolated from other parts.

According to a tenth aspect, in any one of the first to seventh and ninth aspects, the cooling water pool is opened into a dry well region in the containment vessel. This is a reactor cooling device.

The eleventh means is the first means and comprises a cooling water tank for storing cooling water and a means for adding heat generated in the reactor pressure vessel to the cooling water in the cooling water tank as the first means. A reactor cooling system characterized by comprising, as second means, exhaust pressure limiting means for suppressing a pressure shift between the cooling water tank and the inside and outside of the cooling water tank. A twelfth means is the eleventh means, wherein the means for adding heat to the cooling water in the cooling water tank is a system for guiding heat of exhaust steam during automatic depressurization of the reactor pressure vessel to cooling water in the cooling water tank. A reactor cooling device characterized by being configured.

According to a thirteenth means, in the twelfth means, the system for introducing heat into the cooling water in the cooling water tank is provided with exhaust steam when the reactor pressure vessel is automatically depressurized, in the cooling water in the cooling water tank. This is a reactor cooling device characterized by being constituted by a system leading into a condenser.

The fourteenth means is characterized in that, in the twelfth means, the exhaust pressure limiting means is a valve provided in a path communicating the gas phase portion of the cooling water tank with the outside of the cooling water tank. Reactor cooling device.

The fifteenth means is the twelfth means, wherein the exhaust pressure restricting means is a hole opened in a part of a tank wall covering a gas phase portion of the cooling water tank, and the size of the hole is An increase in the pressure of the gas phase of the cooling water tank, which rises due to the heat introduced into the tank, is an opening area that exceeds the pressure drop in the cooling water tank due to the pressure escaping from the hole to the outside of the cooling water tank. Reactor cooling system.

A sixteenth means is the reactor cooling apparatus according to the twelfth means, wherein the exhaust pressure limiting means is a vent pipe communicating between the inside of the liquid phase of the cooling water tank and the outside of the cooling water tank. is there.

[0028] The seventeenth means is any one of the eleventh means to the fourteenth means and the sixth means, wherein the gas phase part in the cooling water tank is provided with a valve in the dry well region in the containment vessel. A reactor cooling device characterized in that it can be opened through a reactor.

The eighteenth means is that water placed at a high place
Position energy with respect to the water level in the lower liquid tank
A reactor for converting energy into a gaseous phase pressure in a low-level liquid tank, and a cooling water injection system for applying the gaseous pressure by the means as a water injection pressure into a reactor pressure vessel. It is a cooling device.

The nineteenth means is a system for applying a hydrostatic head pressure difference between a pool and a tank, which are communicated with each other and arranged at two high and low places, to a gas phase part in the tank at the low place, And a system for applying the pressure in the cooling water tank that stores the cooling water to be injected.

A twentieth means is a cooling water tank for storing the cooling water for injection, and a means for converting thermal energy into a gas phase pressure of a gas phase portion in the cooling water tank using the cooling water for injection as a medium. It is a pressurizing device for cooling water.

A twenty-first means includes a reactor pressure vessel having a built-in reactor core, a suppression pool for condensing steam generated in the reactor pressure vessel at the time of an accident, and a pool water of a level higher than the reactor core and provided in the suppression pool. A flooded system communicably connected to the reactor pressure vessel via a valve, and a gravitational drop provided higher than the suppression pool and communicably connected to the reactor pressure vessel via a valve. In a nuclear reactor equipped with a cooling water pool of a type water injection system and a reactor containment vessel for storing the above-mentioned configuration, the gravity drop water injection system is provided with a first water injection system positioned below a water level in the cooling water pool. A cooling water tank, a first flow path that communicates a liquid phase portion of the cooling water pool with the inside of the first cooling water tank, and a gas phase portion of the first cooling water tank and the first cooling water tank. high place A communication passage provided between the inside of the second cooling water tank, a second passage connecting a liquid phase part in the second cooling water tank and the inside of the reactor pressure vessel via a valve, (1) A reactor facility comprising: a cooling water tank; a third flow passage that communicates cooling water with the inside of the reactor pressure vessel via a valve.

The twenty-second means includes a reactor pressure vessel having a built-in reactor core, a suppression pool for condensing steam generated in the reactor pressure vessel at the time of an accident, and a valve disposed at a higher place than the reactor core via a valve. A cooling water pool of a gravity drop type water injection system communicably connected to the reactor pressure vessel, and a water injection of the gravity drop type water injection system communicably connected to the reactor pressure vessel via a valve. In a reactor facility including a high-pressure tank of a pressure accumulating water injection system in which cooling water is filled at a pressure higher than the pressure, and a reactor containment vessel storing the above-described configuration, the gravity drop water injection system includes a cooling water pool in the cooling water pool. A first cooling water tank located below the water level of the first cooling water tank, a first flow path communicating between a liquid phase portion of the cooling water pool and the inside of the first cooling water tank, and a gas phase of the first cooling water tank. Part and the first cooling water tank A communication passage provided between the second cooling water tank at a higher elevation and a second flow connecting a liquid phase portion in the second cooling water tank and a reactor pressure vessel via a valve; A reactor facility comprising: a passage; and a third flow passage that communicates cooling water through a valve with the first cooling water tank and the reactor pressure vessel.

The twenty-third means includes a reactor pressure vessel having a built-in reactor core, a suppression pool for condensing steam generated in the reactor pressure vessel at the time of an accident, and a pool water located higher than the reactor core and being provided in the suppression pool. A flooded system communicably connected to the reactor pressure vessel via a valve, and a gravitational drop provided higher than the suppression pool and communicably connected to the reactor pressure vessel via a valve. A cooling water pool of a type water injection system, and a pressure accumulating water injection system which is connected to the reactor pressure vessel via a valve so as to be able to communicate with the cooling water pool and is filled with cooling water at a higher pressure than the water injection pressure of the gravity drop type water injection system. In a nuclear reactor equipped with a high-pressure tank and a reactor containment vessel for storing the above-described configuration, the gravity-dropping water injection system may include a first cooling water positioned below a water level in the cooling-water pool. A first flow path communicating the liquid phase portion of the cooling water pool with the inside of the first cooling water tank; and a gas phase portion of the first cooling water tank and a higher position than the first cooling water tank. A communication passage provided between the second cooling water tank and a second flow path connecting a liquid phase part in the second cooling water tank and a reactor pressure vessel via a valve; Reactor equipment comprising: a first cooling water tank; a third flow passage for communicating cooling water via a valve with the inside of the reactor pressure vessel;

A twenty-fourth means is the twenty-first means, wherein the cooling water pool is divided into a plurality of parts, a part of all the parts is communicated with the first cooling water tank side, and the other part is directly connected to the reactor through a valve. Reactor equipment characterized in that it is communicably connected to a pressure vessel.

Twenty-fifth means is characterized in that, in the twenty-first means, a condenser for condensing steam discharged from the reactor pressure vessel is provided in another section of all sections of the cooling water pool. Nuclear reactor equipment.

A twenty-sixth means is the nuclear reactor equipment according to the twenty-second means or the twenty-third means, wherein a plurality of high-pressure tanks of the accumulator / water injection system have different pressures in the tanks.

The twenty-seventh means is the twenty-second means, the twenty-third means, the twenty-fourth means, or the twenty-fifth means, wherein the pool water of the suppression pool is in contact with the inner surface of the steel plate wall of the containment vessel, and corresponds to the inner surface. The reactor equipment is characterized in that pool water of an outer peripheral pool outside the containment vessel is in contact with the outer surface of the reactor.

The twenty-eighth means is the reactor equipment according to the twenty-seventh means, wherein an air-cooling duct of an air-cooling equipment is provided along the wall of the reactor containment vessel at a position higher than the outer peripheral pool. is there.

A twenty-ninth means is the twenty-first means, wherein the pool water of the suppression pool is in contact with the inner surface of the steel plate wall of the containment vessel, and the outer surface corresponding to the inner surface has an outer periphery outside the reactor containment vessel. The pool pool water comes in contact,
Along the steel plate wall of the containment vessel at a higher place than the outer peripheral pool, an air-cooling duct of air cooling equipment is provided, between the structure in the containment vessel and the inner surface of the containment vessel. A partition plate for vertically partitioning the formed wet well space is provided.The upper and lower gas phase portions of the partition plate are communicated with each other by a flow path, and the upper gas phase part and the pool water of the suppression pool are separated by another flow path. Reactor equipment characterized by communication.

According to the thirtieth means, the water storage area of the gravity drop type water injection system for the reactor pressure vessel is provided at least at both high and low places and other places higher than the low water storage area. By pressurizing the gas phase of the water storage area at the low point with the head pressure difference between the respective water storage areas of the area, applying the pressure of the gas phase to the water storage area of the other area, The timing of starting water injection from the water storage area at the low point is shifted to the high pressure side, and the timing of starting water injection from the low water storage area is shifted to the low pressure side.

[0042]

According to the first means, the potential energy based on the water level difference or the heat energy added to the water when water injection is required is applied as pressure into the cooling water tank, and the cooling water in the cooling water tank has a valve. In the conductive state, an operation of injecting water into the reactor core at the water injection pressure based on the sum of the applied pressure and the potential energy higher than the reactor core is obtained.

According to the second means, since the water in the cooling water pool is about to descend to the first cooling water tank through the first flow path, the static head between the cooling water pool and the first cooling water tank is increased. The pressure of the pressure difference compresses the gas phase in the first cooling water tank and increases the pressure of the gas phase. The pressure of the gas phase portion is transmitted to the second cooling water tank via the communication path, and makes the pressure in the second cooling water tank equal to the pressure of the gas phase portion. For this reason, when the valve of the second flow path becomes conductive, the second
In the cooling water in the cooling water tank, the sum of the potential energy and the pressure of the gas phase part becomes the injection pressure, and the operation of injection into the reactor pressure vessel is obtained.

According to the third means, in addition to the action of the second means, after the start of the water injection from the second cooling water tank, the first means having a lower potential energy than the second cooling water tank and having a lower potential energy. An effect is obtained in which the cooling water in the cooling water tank is injected into the reactor pressure vessel. According to the fourth means, in addition to the action of the third means, the third flow path which is a water supply passage from the first cooling water tank to the reactor pressure vessel, and the third flow path from the second cooling water tank to the reactor pressure vessel. Since the second flow path, which is a water injection furnace, is independent of each other, even if one of the two flow paths cannot be used for the water injection operation, an operation of performing water injection in the other flow path can be obtained.

According to the fifth means, in addition to the action of the second means, the pressure of the gas phase portion of the first cooling water tank, whose pressure has been increased by the water of the cooling water pool, is transferred to the third cooling water tank by the communication passage. The sum of the pressure and the potential energy with respect to the fourth cooling water tank that the cooling water in the third cooling water tank is going to descend through the fourth flow path to the fourth cooling water tank is added. The pressure in the fourth cooling water tank is increased. When the increased pressure is applied to the inside of the second cooling water tank through the communication passage and the valve of the second flow path is brought into the conductive state, the cooling water in the second cooling water tank increases the potential energy to the potential energy. The sum of the pressure and the pressure becomes the water injection pressure, and the effect of water being injected into the reactor pressure vessel through the second flow path is obtained.

According to the sixth means, in addition to the action of the fifth means, the water injection pressure decreases in the order of the second cooling water tank, the fourth cooling water tank, and the first cooling water tank. The second cooling water tank, the fourth cooling water tank, and the first cooling water tank are sequentially shifted so that a water injection action into the reactor pressure vessel is obtained.

According to the seventh means, in addition to the function of the sixth means, the second cooling water tank, the fourth cooling water tank, and the second cooling water tank, which are the water injection flow paths to the reactor pressure vessel. Since the flow path, the fifth flow path, and the third flow path are independent of each other,
Even if one of the flow passages interferes with water injection, the effect of achieving water injection in other flow passages is obtained.

According to the eighth means, in addition to the action of the second means or the third means, when water injection into the reactor pressure vessel is necessary, the valve is brought into a conductive state, and the inside of the cooling water pool and the reactor pressure are controlled. The pressure in the vessel is equalized so that the cooling water in the cooling water pool can be easily injected into the reactor pressure vessel, so that an earlier injection action can be obtained.

According to the ninth means, in addition to the action of the second means or the third means, a part of the cooling water pool is used for the second cooling water tank area to supply water to the reactor pressure vessel. Is obtained.

According to the tenth means, in addition to the operation of any one of the first to seventh means and the ninth means, the pressure in the cooling water pool is increased in the dry well region at the time of the accident. Since the pressure is increased to the same level as the pressure, an effect is obtained that the timing of starting water injection into the reactor pressure vessel is advanced by the increased pressure.

According to the eleventh means, in addition to the action of the first means, when the thermal energy generated in the reactor pressure vessel is added to the cooling water in the cooling water tank, the cooling water in the tank partially Evaporation causes the pressure in the tank to increase, and the pressure is isolated within the cooling water tank within a safe pressure range by the exhaust pressure limiting means. The pressure due to the potential energy is added to the increased pressure, so that the cooling water in the tank is injected into the reactor pressure vessel.

According to the twelfth means, in addition to the function of the eleventh means, heat energy exhausted during automatic depressurization of the reactor pressure vessel is added to the cooling water in the cooling water tank in a vapor state, and the steam is cooled. Condensed by the cooling water in the water tank, the cooling water is heated and evaporated, and the pressure in the cooling water tank is increased by the partial pressure of the evaporated vapor.

According to the thirteenth means, in addition to the action of the twelfth means, the high-temperature steam exhausted when the reactor pressure vessel is automatically depressurized is guided into the condenser in the cooling water tank and passes through the condenser. Exchanges heat with the cooling water in the cooling water tank. For this reason, thermal energy is added to the cooling water in the cooling water tank, and an effect of increasing the pressure in the cooling water tank is obtained.

According to the fourteenth means, in addition to the action of the twelfth means, an action is obtained in which the pressure in the cooling water tank is released to the outside of the tank by opening and closing the valve to fall within a safe pressure range.

According to the fifteenth means, in addition to the function of the twelfth means, when the pressure in the cooling water tank rises, the excess pressure escapes from the hole formed in the cooling water tank to the outside of the tank and becomes excessive. An effect is obtained in which damage to the tank due to pressure can be prevented without providing an operating part such as a valve.

According to the sixteenth means, in addition to the function of the twelfth means, since the vent pipe is immersed in the liquid phase portion in the cooling water tank, it is always in a liquid-sealed state. When the pressure in the cooling water tank increases, the water surface in the vent pipe is pushed up, and an effect of suppressing the pressure in the cooling water tank from becoming excessive is obtained.

According to the seventeenth means, the first to the eleventh means
In addition to the action of any one of the four means and the sixteenth means, the pressure in the cooling water tank becomes equal to the pressure in the increased dry well area at the time of the accident by opening the valve. The effect of hastening the timing of starting water injection from the water tank into the reactor pressure vessel is obtained.

According to the eighteenth means, the potential energy of the high place water is changed to the pressure in the low place liquid tank and the pressure is used as the water supply pressure of the cooling water injection system, and the water supply into the reactor pressure vessel is started. The effect of hastening the timing is obtained.

According to the nineteenth means, it is possible to obtain the function of adding the pressure based on the hydrostatic head pressure difference between the high and low tanks to the water injection cooling water tank to secure the water injection pressure.

According to the twentieth means, it is possible to obtain the effect that the heat energy is converted into the pressure and the pressure is added to the water injection cooling water tank to secure the water injection pressure.

According to the twenty-first means, in the event of an accident, steam is condensed in the suppression pool to reduce the pressure in the reactor pressure vessel, and the timing of starting water injection into the reactor pressure vessel by the gravity drop water injection system is advanced. After the start of water injection into the reactor pressure vessel by the gravity drop water injection system, the pressure in the reactor pressure vessel has also dropped considerably, and a submergence system with lower potential energy than the gravity drop water injection system enters the reactor pressure vessel. Water injection can be started. At that time, the gravity drop water injection system is configured such that the water in the cooling water pool attempts to descend to the first cooling water tank through the first flow path, and the hydrostatic head between the cooling water pool and the first cooling water tank. The pressure of the pressure difference compresses the gas phase in the first cooling water tank and increases the pressure of the gas phase. The pressure of the gas phase portion is transmitted to the second cooling water tank via the communication path, and makes the pressure in the second cooling water tank equal to the pressure of the gas phase portion. For this reason, when the valve of the second flow path becomes conductive, the sum of the potential energy and the pressure of the gas phase part becomes the injection pressure of the cooling water in the second cooling water tank, and the cooling water in the reactor pressure vessel In this way, the water injection start timing by the gravity drop water injection system is shifted to the high pressure side to advance the water injection start timing, and the water injection by the submergence system is also accelerated. The effect that the effect of suppressing the rise in the pressure inside the furnace containment vessel can be achieved at an early stage is obtained.

According to the twenty-second means, in the event of an accident, steam is condensed in the suppression pool to reduce the pressure in the reactor pressure vessel, and water injection into the reactor pressure vessel by the accumulator water injection system is started. Water injection into the reactor pressure vessel by the gravity drop water injection system is started. At that time, the gravity drop water injection system is configured such that the water in the cooling water pool attempts to descend to the first cooling water tank through the first flow path, and the hydrostatic head between the cooling water pool and the first cooling water tank. The pressure of the pressure difference compresses the gas phase in the first cooling water tank and increases the pressure of the gas phase. The pressure of the gaseous phase is second
The pressure transmitted to the cooling water tank makes the pressure in the second cooling water tank equal to the pressure in the gas phase. For this reason, when the valve of the second flow path becomes conductive, the sum of the potential energy and the pressure of the gas phase part becomes the injection pressure of the cooling water in the second cooling water tank, and the cooling water in the reactor pressure vessel The water injection start timing by the gravity drop water injection system is shifted to the high pressure side, so that the water injection start timing is advanced, and the water injection by the flooding system is also accelerated. For this reason, the injection start timing of the pressure accumulating water injection system into the reactor pressure vessel can also be shifted to a higher pressure side, and the effect of suppressing a rise in the pressure in the reactor pressure vessel or the containment vessel can be achieved early. The degree of freedom of design is expanded, such as a smooth transition from water injection by the pressure accumulating water injection system to water injection by the gravity falling water injection system, or the burden of water injection by the pressure accumulating water injection system being partially borne by the gravity falling water injection system. A possible function is obtained.

According to the twenty-third means, in the event of an accident, steam is condensed in the suppression pool to reduce the pressure in the reactor pressure vessel, and water injection into the reactor pressure vessel by the accumulator water injection system is started. Water injection into the reactor pressure vessel by the gravity drop water injection system was started.After water injection into the reactor pressure vessel was started by the gravity drop water injection system, the pressure in the reactor pressure vessel also dropped considerably, A submergence system with a lower potential energy than the water injection system can start water injection into the reactor pressure vessel. At that time, the gravity drop water injection system is configured such that the water in the cooling water pool attempts to descend to the first cooling water tank through the first flow path, and the hydrostatic head between the cooling water pool and the first cooling water tank. The pressure of the pressure difference compresses the gas phase in the first cooling water tank and increases the pressure of the gas phase. The pressure of the gas phase portion is transmitted to the second cooling water tank via the communication path, and makes the pressure in the second cooling water tank equal to the pressure of the gas phase portion. For this reason, when the valve of the second flow path becomes conductive, the sum of the potential energy and the pressure of the gas phase part becomes the injection pressure of the cooling water in the second cooling water tank, and the cooling water in the reactor pressure vessel The water injection start timing by the gravity drop water injection system is shifted to the high pressure side, so that the water injection start timing is advanced, and the water injection by the flooding system is also accelerated. For this reason, the injection start timing of the pressure accumulating water injection system into the reactor pressure vessel can also be shifted to a higher pressure side, and the effect of suppressing a rise in the pressure in the reactor pressure vessel or the containment vessel can be achieved early. The degree of freedom of design is expanded, such as a smooth transition from water injection by the pressure accumulating water injection system to water injection by the gravity drop water injection system, or partial burden of the water injection by the pressure accumulating water injection system on the water injection by the gravity falling water injection system. In addition to this, it is possible to obtain the effect of improving the coordination of the water injection schedule of each water injection system.

According to the twenty-fourth means, in addition to the operation of the twenty-first means, the cooling water in a part of the cooling water pool is supplied to the reactor pressure vessel during the timing of starting the water injection between the gravity drop type water injection system and the flooding system. Since the timing of water injection comes, an effect that a fine water injection schedule can be achieved is obtained.

According to the twenty-fifth means, in addition to the operation of the twenty-first means, the steam in the reactor pressure vessel can be condensed by the cooling water in the cooling water pool. The effect of accelerating the reduction by the condensation, and thereby earliering the injection timing of the gravity drop type injection system or reducing the injection pressure can be obtained.

According to the twenty-sixth means, the twenty-second means or the second
In addition to the functions of the three means, the operation of starting injection of water from the plurality of tanks of the pressure accumulating water injection system into the reactor pressure vessel with a time lag can achieve an effect of achieving a fine water injection schedule.

According to the twenty-seventh means, the twenty-first means or the second means
In addition to the action of the third means or the twenty-fourth means or the twenty-fifth means, since the reactor containment vessel is water-cooled by the outer peripheral pool, the effect of reducing the pressure in the reactor containment vessel is good, and accordingly the An effect is obtained in which the pressure immediately drops and the timing of starting water injection by each water injection system is advanced, or if not, the water injection pressure can be reduced.

According to the twenty-eighth means, an effect is obtained that the part of the upper containment vessel that cannot be water-cooled can be cooled by air cooling to promote the function of the twenty-seventh means.

According to the twenty-ninth means, in addition to the action of the twenty-first means, the remaining steam which cannot be completely condensed even in the suppression pool moves to the wet well space above the partition plate and is mainly cooled by air cooling to condense. Then, it is returned to the suppression pool water, and the condensation can also reduce the pressure inside the reactor containment vessel, especially the suppression pool chamber.With this, the pressure inside the reactor pressure vessel is also reduced well, and An effect that the water injection start timing is advanced or the water injection pressure can be reduced otherwise is obtained.

According to the thirtieth means, since the water injection start timing of the gravity drop water injection system can be dispersed between the high pressure side and the low pressure side, the operation of expanding the water injection operation area by the gravity drop water injection system can be obtained.

[0071]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment is shown in FIG. The first embodiment will be described below.

The first embodiment is an example in which the present invention is applied to a boiling water reactor having an electric power of 1350 MW.

The steel containment vessel 10 separates the inside and outside of the containment area. The reactor containment vessel 10
Is immersed in an annular outer peripheral pool 15.
The outer peripheral pool 15 is provided with a steam discharge duct 86 for communicating the gas phase portion of the outer peripheral pool 15 with the outside world.

The outside of the containment vessel 10 is surrounded by a reinforced concrete building 200.

The outer peripheral surface of the reactor containment vessel 10 above the outer peripheral pool 15 is provided with air cooling equipment for the purpose of cooling the outer peripheral surface. The air-cooling equipment is provided in the reinforced concrete building 200 as an air-cooling duct 33 provided along the outer peripheral surface of the reactor containment vessel 10 above the outer peripheral pool 15 and an outside air intake to the air-cooling duct 33. The air inlet 32 communicates with the lower end of the air cooling duct 33, and the exhaust duct 87 communicates between the air cooling duct 33 and the outside of the reinforced concrete building 200 at the upper end of the air cooling duct 33. Is done.

In the reactor containment vessel 10, a concrete structure 16 is constructed with structural walls made of reinforced concrete.

The annular space between the outer peripheral surface of the concrete structure 16 and the inner peripheral surface of the containment vessel 10 is secured as a wet well 13 space. The space of the wet well 13 and the space of the operation floor 30 which is a space above the concrete structure 16 are normally airtightly partitioned by a pressure release plate 31.

Inside the concrete structure 16, a dry well 11 space in which the reactor pressure vessel 1 is stored, and an annular suppression pool 12 in which cooling water is stored.
And a cooling pan pool 90 and a second cooling water tank 91 disposed above the suppression pool 12.
Are formed.

The cooling water of the suppression pool 12 is communicated between the inside and outside of the structural wall by a communication hole 18 formed in a reinforced concrete structure wall.
The two gas phase portions are communicated with each other by the other communication holes 18 inside and outside the structural wall.

The space between the dry well 11 and the cooling water in the suppression pool 12 is communicated by a vent pipe 17.

The cooling pan pool 90 and the second cooling water tank 9
1 is annular when viewed from above, and is adjacent at the same height. The gas phase of the cooling pan pool 90 communicates directly with the dry well 11 space through the dry well communication passage 104.

It is lower than the cooling pan pool 90,
A first cooling water tank 92 is provided above the suppression pool 12 in the dry well 11 space.

The upper end surface of the concrete structure 16 is an operation floor 30, and the operation floor 30 has a manipulator 80 capable of handling components in the reactor pressure vessel 1.
Is equipped. An overhead crane 201 is provided above the manipulator 80 in the operation floor 30 space, and the overhead crane 201 can turn along an annular traveling path 202 supported from the reactor containment vessel 10.

The reactor pressure vessel 1 incorporates a reactor core 2, and an internal pump 106 supplies cooling water in the reactor pressure vessel 1 to the reactor core 2.

The cooling water heated in the reactor core 2 is converted into high-temperature and high-pressure steam and supplied to the outside of the reactor containment vessel 10 as energy for rotating the drive turbine of the generator. The main steam pipe 3
Is connected to the reactor pressure vessel 1 and the reactor containment vessel 10
Penetrates. A plurality of the main steam pipes 3 are provided, and an isolation valve is provided in the middle thereof. In the event of an accident, the isolation valve is closed to close the main steam pipe 3.

The high-temperature and high-pressure steam is consumed for rotating the drive turbine, and then condensed in a condenser. The cooling water obtained by the condensation is converted into atomic water. Water is supplied into the furnace pressure vessel 1, and the water supply passage is a water supply pipe 4. The water supply pipe 4
Are connected to the reactor pressure vessel 1 through the reactor containment vessel 10. This water supply pipe 4 also has a structure that can be closed similarly to the main steam pipe 3.

In any penetrating part, the reactor containment vessel 1
The atmosphere and pressure inside the chamber are airtight so that the atmosphere and pressure do not escape to the outside.

Each main steam pipe 3 has a reactor containment vessel 10
An automatic decompression system is connected to the part passing through the inside.
The automatic pressure reducing system includes an automatic pressure reducing valve 23 connected to the main steam pipe 3 and an automatic pressure reducing valve 23 connected to the automatic pressure reducing valve 23.
And an automatic pressure-reducing system pipe 143 for introducing the steam discharged from the water into the suppression pool 12 water. The automatic pressure reducing valve 23 is operated to detect a cooling water leak or a sudden drop in pressure, which is the cause of the cooling water loss accident, and to open based on the detection.

The reactor containment vessel 10 contains a gravity drop type water injection system and a flooding system as emergency core cooling systems.

The gravity drop type water injection system has the following configuration.

That is, the inside of the second cooling water tank 91 and the inside of the reactor pressure vessel 1 are connected by the second pipe 93 which is the second flow path. The upper end of the second pipe 93 is connected to the second cooling water tank 91.
The lower end is connected to a portion of the reactor pressure vessel 1 higher than the core 2. In the middle of the second pipe 93, a second on-off valve 9 is provided by a second cooling water tank 91.
9 is equipped with a second check valve 97 rather than the reactor pressure vessel 1. The second check valve 97 is connected to the second cooling water tank 9.
The check direction is set so as to allow passage from the side 1 to the reactor pressure vessel 1 and prevent passage in the opposite direction.

The inside of the second cooling water tank 91 and the inside of the first cooling water tank 92 are connected by a pressure equalizing pipe 95 which is a communication passage so that the gas phase portions above the water surface can communicate with each other.

The inside of the first cooling water tank 92 and the inside of the cooling water pool 90 are connected by a first pipe 94 as a first flow path. The upper end of the first pipe 94 is connected to the bottom of the cooling water pool 90, and the lower end is submerged in the cooling water in the first cooling water tank 92.

A third pipe 96, which is a third flow path connecting the first cooling water tank 92 and an intermediate portion of the second pipe 93 between the second on-off valve 99 and the second check valve 97, is provided. A first opening / closing valve 100 is provided at an intermediate position from the first cooling water tank 92, and a first check valve 98 is provided at the reactor pressure vessel 1.
The first check valve 98 has a check direction set to allow passage from the first cooling water tank 92 side to the reactor pressure vessel 1 side and prevent passage in the opposite direction.

Before the operation of the reactor, the first on-off valve 100 and the second
The on-off valve 99 is closed, and the cooling water is substantially filled in the cooling water pool 90 and the second cooling water tank 91. The cooling water pool 90 and the second cooling water tank 91 are provided with a freely openable and closable water inlet for introducing cooling water.
After the cooling water is filled, the water inlet is closed airtightly. By putting the cooling water into the cooling water pool 90, a part of the cooling water enters the first cooling water tank 92 through the first pipe 94, and the gas phase in the second cooling water tank 91 becomes high pressure.
Thus, the first cooling water tank 92 is connected to the first pipe 94
A state in which a water level is formed above the lower end opening.
Accordingly, the first cooling water tank 92 is moved from the surface of the cooling water pool 90 through the first pipe 94 to the first cooling water tank 92.
The head pressure over the water level inside is applied. This pressure is applied to the second cooling water tank 91 through the pressure equalizing pipe 95. For this reason, the hydrostatic head from the second cooling water tank 91 into the reactor pressure vessel 1 is equal to the water level between the water level in the second cooling water tank 91 and the inlet of the reactor pressure vessel 1 in the second pipe 93. The standby state is established with the sum of the water head between the water surface of the cooling water pool 90 and the water level in the first cooling water tank 92.

The above is the gravity drop type water injection system. Next, the configuration of the flooding system will be described below.

The submergence piping 84 connects the water in the suppression pool 12 to the inside of the reactor pressure vessel 1 at the upper part of the reactor core 2 or at a position higher than it. This flooded piping 8
4, a flooded on-off valve 83 is provided near the suppression pool 12, and a flooded check valve 8 is provided near the reactor pressure vessel 1.
5 will be equipped. The non-return valve 85 is set to have a non-return direction so as to allow the flow to the reactor pressure vessel 1 and prevent the flow in the reverse direction.

The above is the configuration of the flooding system.

The following operation is possible in such a reactor facility.

When the operation of the reactor is started, the pressure in the reactor pressure vessel 1 increases. After confirming that the pressure has become higher than the hydrostatic head pressure at the time of the accident from the second cooling water tank 91 into the reactor pressure vessel 1, the first on-off valve 100, the second on-off valve 99 and the flooding system The on-off valve 83 is opened. The flooding on-off valve 83 may be opened earlier.

If the reactor operates normally in this state,
The cooling water in the reactor pressure vessel 1 is supplied to the outside of the reactor containment vessel 10 through the main steam pipe 3 as high-temperature and high-pressure steam,
The vapor is condensed outside the reactor containment vessel 10 and returned to the reactor pressure vessel 1 through the water supply pipe 4 as cooling water.

The high-temperature and high-pressure steam generated in the reactor pressure vessel 1 is supplied to the dry well 11 from the main steam pipe 3 or the like, for example.
If an accident that leaks into the reactor occurs, the cooling water in the reactor pressure vessel 1 will be lost. When such a cooling water loss accident occurs, the automatic pressure reducing valve 23 of the automatic pressure reducing system is opened, and the high temperature and high pressure steam in the reactor pressure vessel 1 is discharged into the suppression pool 12 water through the automatic pressure reducing system piping 143, and the reactor The pressure in the pressure vessel 1 is reduced.

The steam discharged into the suppression pool 12 water is condensed by the cooling water in the suppression pool 12. Due to this condensation action, the rise in pressure inside the reactor containment vessel 10 is weakened, but the pressure gradually rises.

Dry well 11 from the reactor pressure vessel 1 side
The high-temperature and high-pressure steam leaked into the inside increases the pressure of the dry well 11. Dry well 11 with high pressure
The inside atmosphere is blown into the cooling water in the suppression pool 12 through the vent pipe 17. The vapor in the atmosphere blown into the cooling water is condensed by the cooling water in the suppression pool 12, and the gas in the atmosphere that is not condensed is accumulated above the surface of the cooling water in the suppression pool 12, and the pressure in the wet well 13 is reduced. Enhance.

The gas which is not condensed in the suppression pool 12 moves to the space of the wet well 13 together with the steam from the cooling water surface in the suppression pool 12 through the communication hole 18 in the upper part of the suppression pool 12, and the pressure is dispersed due to the transfer and suddenly Avoid rising.

When the above-described respective condensation actions continue, the pressure in the dry well 11 decreases, and the pressure in the reactor pressure vessel 1 easily shifts into the dry well 11, and the pressure in the reactor pressure vessel 1 Drops. On the other hand, the level of the cooling water in the suppression pool 12 rises due to the condensed water generated by each condensing action.

When the pressure in the wet well 13 space increases, the pressure release plate 31 is opened by the increased pressure in the wet well 13 space. When the pressure release plate 31 is opened, the pressure in the space of the wet well 13 is increased.
Escape to space 0.

For this purpose, the suppression pool 12
Can further accept the atmosphere containing steam in the dry well 11, and contribute to further reducing the pressure in the reactor pressure vessel 1 and the dry well 11. For this reason, the pressure in the reactor pressure vessel 1 is better
As a result, the pressure in the reactor pressure vessel 1 rapidly decreases.

With the condensing action in the suppression pool 12, the water level and the water temperature of the suppression pool 12 rise, and the upper communication hole 18 in the suppression pool 12 is submerged.

In such a situation, the outer peripheral pool 15
The cooling water in the suppression pool 12 close to the reactor containment vessel 10 wall is cooled by the pool water inside the reactor containment vessel 10 wall as a heat transfer medium. The cooled cooling water in the suppression pool 12 adjacent to the wall of the containment vessel 10 descends in the suppression pool 12 to supply the cooling water in the suppression pool 12 through both communication holes 18 in the upper and lower portions of the suppression pool 12. Circulate.
Due to the circulation, the entire cooling water is cooled, and an increase in pressure in the wet well 13 is suppressed.

Further, when the temperature in the wet well 13 space or the operation floor 30 space rises, the outside air in the air-cooled duct heated by the temperature rises, and the rising force causes the air-cooling duct 32 to move from the air intake 32 to the air-cooling duct 33. The inside of the reactor containment vessel 10 is cooled by sucking cold outside air into the inside and is discharged from the exhaust duct 87 to the outside. This also cools the entirety of the containment vessel 10 and suppresses a rise in pressure.

Since the rise in the pressure in the reactor containment vessel 10 is suppressed, the reactor containment vessel 1
The pressure shifts quickly into the reactor pressure vessel 1
Reduction of the internal pressure is well promoted.

The pressure of the cooling water pool 90 is set to the dry well 1
1 and by the drywell communication passage 104. When the pressure in the reactor pressure vessel 1 is
When the pressure becomes lower than the hydrostatic head pressure at the time of accident from the reactor 1 into the reactor pressure vessel 1, first, water injection into the reactor pressure vessel 1 by the gravity drop type water injection system is started.
The pressure drop in the reactor pressure vessel 1 is obtained by the replenishment of the cooling water lost from the inside and the cooling action of the cooling water.

Reactor pressure vessel 1 by gravity drop type water injection system
When water injection into the inside is started, first, the second cooling water tank 91
The cooling water in the reactor is injected into the reactor pressure vessel 1 through the second pipe 93 through the second check valve 97. With this water injection, the pressure in the second cooling water tank 91 decreases, and the pressure in the first cooling water tank 92 decreases with the decrease in pressure. The water moves into the first cooling water tank 92 through the pipe 94 and the water level in the second cooling water tank 91 rises. The inside of the reactor pressure vessel 1 is cooled by a water injection action from the second cooling water tank 91 into the reactor pressure vessel 1, and the pressure in the reactor pressure vessel 1 is further reduced. With this configuration, the cooling water in the first cooling water tank 92 passes through the third pipe 96 through the first check valve 98, enters the second pipe 93, and remains in the second pipe 93. The coolant merges with the coolant from the second coolant tank 91 and is injected into the reactor pressure vessel 1.

Reactor pressure vessel 1 by gravity drop type water injection system
The principle of water injection into the interior is as shown in FIGS. FIGS. 4, 5, and 6 are diagrams for illustrating the principle of water injection, and do not correspond to the embodiment of FIG. 1 in specific points, but have equivalent contents as the principle of water injection.

That is, as shown in FIG. 4, the position of the cooling water in the cooling water pool 90 is higher than the position of the cooling water in the first cooling water tank 92. Is higher than the potential energy of the cooling water in the first cooling water tank 92, and the difference between the potential energy applied to both the cooling waters and the pressure in the dry well 11 applied to the water surface of the cooling water pool 90. The cooling water in the cooling water pool 90 tends to descend into the first cooling water tank 92 and compresses the gas phase in the first cooling water tank 92. Since the pressure in the reactor pressure vessel 1 during operation is higher than the compression pressure, the first on-off valve 100 and the second on-off valve 99 are opened after the operation of the reactor, but the first check valve 98 The second check valve 97 does not open. For this reason, the pressure in the first cooling water tank 92 increases. The increased pressure
The pressure is also applied to the inside of the second cooling water tank 91 through the equalizing pipe 95. In addition, the second cooling water tank 91 is
Since the cooling water in the second cooling water tank 91 is higher than the cooling water in the first cooling water tank 92, the cooling water in the second cooling water tank 91 is provided at a position higher than the cooling water tank 92, and the cooling water in the standby state in the state of FIG. It is said.

During normal operation, the pressure in the reactor pressure vessel 1 is lower than the injection pressure applied to the cooling water in the second cooling water tank 91.
Since the internal pressure is high, the second check valve 97 is not opened in the standby state, and the water injection operation is not performed.

When a coolant loss accident occurs, as described above, the pressure in the reactor pressure vessel 1 decreases, and conversely, the pressure in the dry well 11 increases. The trend of the pressure drop in the reactor pressure vessel 1 shows a tendency to change like a characteristic curve indicated by a dotted line in FIG. 8A. On the contrary, the pressures in the first cooling water tank 92 and the second cooling water tank 91 are changed by the dashed line or the two-dot chain line in FIG. 8A when the cooling water pool 90 receives the increased pressure in the dry well 11. To rise.

As a result, when the pressure in the reactor pressure vessel 1 becomes lower than the injection pressure from the second cooling water tank 91,
The second check valve 97 is opened, and the injection of cooling water from the second cooling water tank 91 into the reactor pressure vessel 1 is started.

FIG. 5 shows how water is injected from the second cooling water tank 91 into the reactor pressure vessel 1. In FIG. 5, the solid arrows indicate the direction of the flow of the cooling water, and the dotted arrows indicate the direction of the flow of the gas phase. At this time, since the injection pressure from the first cooling water tank 92 into the reactor pressure vessel 1 is lower than that of the second cooling water tank 91 and lower than the pressure in the reactor pressure vessel 1, the first reverse The stop valve 98 does not open.

After the injection of water from the second cooling water tank 91 is started, a time comes when the pressure in the second cooling water tank 91 decreases. At that time, the cooling water in the cooling water pool 90 is discharged. The cooling water flows down into the first cooling water tank 92 through the one pipe 94, and the cooling water in the first cooling water tank 92 becomes almost full.

The injection of cooling water from the second cooling water tank 91 into the reactor pressure vessel 1 proceeds, and the reactor pressure vessel 1
When the internal pressure decreases, the water injection pressure from the first cooling water tank 92 eventually exceeds the pressure in the reactor pressure vessel 1, and the first check valve 98 opens.

For this reason, the cooling water in the first cooling water tank 92 together with the cooling water from the second cooling water tank 91 remaining in the second pipe 93 passes through the third pipe 96 and the second pipe 93. And water is injected into the reactor pressure vessel 1. The state of water injection from the first cooling water tank 92 is shown in FIG.

When the injection of water from the first cooling water tank 92 and the second cooling water tank 91 into the reactor pressure vessel 1 is completed,
The cooling water in the first cooling water tank 92 and the second cooling water tank 91 becomes empty as shown in FIG.

The timing of starting water injection from the second cooling water tank 91 into the reactor pressure vessel 1 is determined by the second cooling water tank 91.
In addition to the pressure in the dry well 11, a pressure corresponding to the difference in potential energy between the cooling water in the first cooling water tank 92 and the cooling water in the cooling water pool 90 is applied, and the pressure is set as the injection pressure. 8a, the injection pressure is higher than the injection pressure characteristic of the conventional gravity drop type injection system shown by the solid line curve in FIG.
Injection of cooling water can be started at a point in time when the pressure in the inside is higher, and when the amount of injected water is shown as time elapses, it becomes as shown by a dashed line with respect to a required injection flow rate shown by a dotted line in FIG. 8b.

Conversely, the timing of starting water injection from the first cooling water tank 92 into the reactor pressure vessel 1 is such that the first cooling water tank 92 is at a position lower than the cooling water storage pool of the conventional gravity drop type water injection system. Therefore, the injection pressure of the first cooling water tank 92 is lower than the injection pressure of the conventional gravity drop type injection system,
As shown by the two-dot chain line in FIG. 8A, the water pressure is shifted to a lower pressure side, that is, a later side than the water injection start timing of the conventional gravity drop type water injection system. For this reason, as shown by the two-dot chain line in FIG.
Water can continue to be injected from the accident to a later time than with the conventional gravity drop type water injection system, and the flow rate significantly exceeds the required water flow rate in a short time as with the conventional gravity drop type water injection system, resulting in lower efficiency. No bad results.

In the gravity drop type water injection system according to the principle of the present invention, the time from the accident to the injection of cooling water can be reduced as compared with the conventional gravity drop type water injection device. This is equivalent to making the installation position of the cooling water pool 90 seemingly higher, and the installation height of the cooling water pool 90 required to obtain the same water injection performance is lower than that of the conventional gravity drop type water injection system. Therefore, the height of the containment vessel 10 can be significantly reduced. Further, by extending the water injection time zone to both the high pressure side and the low pressure side, it is possible to obtain a long-time cooling water injection action.

This principle is based on a configuration in which the portion of the first pipe 94 that is contained in the first cooling water tank 92 is bent into a U-shape so that the end is directed upward, as shown in FIG. Even if the lower end of the first pipe 94 is not submerged in the cooling water in the first cooling water tank 92, the gas phase in the first cooling water tank 92 is
This is also established by preventing the cooling water pool 90 from passing through the pipe 94.

In the flooding system shown in FIG. 1, water is injected by a gravity drop type water injection system, and the pressure in the reactor pressure vessel 1 is increased.
When the water level falls below the water injection pressure determined by the water level of the suppression pool 12, the flooded check valve 85 opens and the cooling water in the suppression pool 12 is injected into the reactor pressure vessel 1 through the flooded piping 84.

A part of the cooling water injected into the reactor pressure vessel 1 from the gravity drop type water injection system leaks into the dry well 11 in a vapor state or a liquid state and accumulates in the lower part of the dry well 11 and in the suppression pool 12. . The cooling water accumulated in the suppression pool 12 is again poured into the reactor pressure vessel 1 in a flooded system, and is used for cooling the reactor core 2.

Thus, the inside of the reactor pressure vessel 1 is cooled for a long time after the accident.

That is, in the case of water injection from the cooling water pool in the conventional gravity drop type water injection system, first, the sum of the pressure in the dry well and the water injection head of the cooling water pool is higher than the pressure in the reactor pressure vessel 1. From the point in time when the cooling water becomes large, all the cooling water is injected at once, and the excess cooling water flows out from the break. In contrast, in the gravity drop type water injection system of the present embodiment,
As the pressure in the reactor pressure vessel 1 decreases, the water injection pressure and the cooling water tank are automatically switched to continue the water injection, and the cooling water can be injected for a long time from the early stage after the accident. This makes it possible to perform cooling for a longer time than in the case of using the water injection characteristics of the conventional gravity drop type water injection system indicated by a solid line in FIG. 8B, and improves safety after an accident.

Further, by determining the capacities of the cooling water pool 90, the first cooling water tank 92, and the second cooling water tank 91 and their installation heights, it is possible to control the water injection flow rate.
Since the amount of cooling water required for core cooling corresponding to the generation of decay heat of the core 2 can be appropriately injected, the cooling water pool 9
0. The capacity of each cooling water tank 91, 92 can be optimized, and the volume of the storage container can be reduced.

Further, since the potential energy of the cooling water between the cooling water pool 90 and the first cooling water tank 92 is converted into pressure and applied to the second cooling water tank 91, The water injection pressure can be increased without moving the installation position of the water tank 91 to a higher position. Therefore, it is not necessary to increase the height of the containment vessel when increasing the injection pressure of the gravity drop injection system, and the economical efficiency of the reactor equipment is improved.

The second embodiment is shown in FIG. Second
Examples are as described below.

The second embodiment is configured by partially changing the configuration of the first embodiment. The partially modified configuration will be described below. The other parts are the same as those of the first embodiment, and the description is omitted.

Concrete Structure 1 in PCV
6, a cooling water second pool 130 is provided at the same height as the cooling water pool 90. The cooling water pool 90 and the cooling water second pool 130 are airtightly partitioned. The gas phase of the cooling water pool 90 is made the same as the pressure inside the dry well through the dry well communication passage 104. Similarly, in the cooling water second pool 130, the gas phase also passes through the dry well 1
1 is maintained at the same pressure.

The lower end of the second cooling water pool 130 is connected to the upper end inlet of the water injection pipe 123 so as to receive the cooling water in the second cooling water pool 130. This water injection pipe 12
3 is connected to the reactor pressure vessel 1 so as to communicate with the inside of the reactor pressure vessel 1.

In the middle of the water injection pipe 123, a water injection opening / closing valve 122 is provided from the second cooling water pool 130, and a water injection check valve 124 is provided from the reactor pressure vessel 1. The water check valve 124 is set to have a check direction so as to allow a flow from the second cooling water pool 130 into the reactor pressure vessel 1 and prevent the flow in the reverse direction.

In the configuration of the second embodiment, when a cooling water loss accident occurs, the same functions as those of the first embodiment can be obtained, but the following functions are additionally provided.

That is, the second cooling water pool 1 at the time of the accident
The injection pressure from 30 into the reactor pressure vessel 1 is shown in FIG.
It is the same as that shown by the solid line in the middle. Therefore, when the first on-off valve 100 and the second on-off valve 99 are opened, the water injection on-off valve 1 is opened.
22 is also opened, in the event of an accident, the second cooling water tank 9
1 after the water injection into the reactor pressure vessel 1 is started and before the water injection from the first cooling water tank 92 into the reactor pressure vessel 1 is started. FIG. 8 shows the cooling water in the second pool 130 which is located at a high altitude.
Water is injected into the reactor pressure vessel 1 as shown by the solid line in FIG. After water injection from the gravity drop water injection system, water injection from the flooded water system is performed, and long-term water injection is continued. According to such a water injection function, at the time of switching between water injection from the second cooling water tank 91 and water injection from the first cooling water tank 92, the water injection flow rate may temporarily fall below the required water injection flow rate. However, this can be complemented by water injection from the second cooling water pool 130. In addition, the first cooling water tank 9
Even if the injection of water from the second or second cooling water tank 91 or both tanks into the reactor pressure vessel 1 is not performed due to a valve failure, a pipe break, or the like, the cooling water second pool 130 does not A cooling function can be obtained by injecting water into the furnace pressure vessel 1.

In the second embodiment, the cooling water pool 90 and the cooling water second pool 130 are partitioned, but they need not be partitioned.

The third embodiment is shown in FIG. Third
The embodiment is configured by partially changing the configuration of the second embodiment. The partially modified configuration will be described below. The other parts are the same as those of the second embodiment, and the description is omitted.

The cooling water second pool 130 is the cooling water pool 9
0 and the dry well 11 are hermetically isolated.
The gas phase portion of the cooling water second pool 130 is provided with a vent pipe 136.
Thereby, it communicates with the outside world outside the reactor building 200.

In the cooling water of the second pool 130, a condenser 135 is incorporated. The condenser 135
And the inside of the main steam pipe 3 are connected to the condenser pipe 139.
Are connected to each other. A condenser open / close valve 137 is provided in the middle of the condenser pipe 139.

The inside of the condenser 135 where the condensed water accumulates and the water in the suppression pool 12 are connected to the condensed water pipe 1
It communicates by 38.

According to the third embodiment, the following functions can be added in addition to the functions according to the second embodiment. That is, when a coolant leakage accident occurs, the condenser on-off valve 137 is opened by remote control. In order to perform the remote operation, the condenser opening / closing valve 137 is an electric valve, so that the opening / closing control of the electric valve can be performed from a remote point.

When the condenser on-off valve 137 is opened after the accident, the high-temperature and high-pressure steam in the reactor pressure vessel 1 enters the condenser 135 from the main steam pipe 3 through the condenser pipe 139.
The cooling water is cooled by the cooling water in the second pool 130 and condensed in the condenser 135. The cooling water in the cooling water second pool 130 is heated and evaporated by the condensation action. The evaporated vapor is discharged to the outside through the vent pipe 136.

The condensed water accumulated in the condenser 135 descends through the condensed water pipe 138 and is discharged into the suppression pool 12, so that the steam newly entering the condenser 135 can be condensed.

When the steam is condensed from the reactor pressure vessel 1 by the condenser 135, the pressure in the reactor pressure vessel 1 after the accident is reduced to a configuration in which the condenser 135 is not added. It can be reduced more quickly than things.

Since the pressure in the reactor pressure vessel 1 decreases more rapidly than in the first and second embodiments, the cooling water in the second cooling water tank 91 and the first cooling water tank 92 does not evaporate. If the cooling water still remains in the cooling water second pool 130, the time from when the cooling water in the second cooling water pool 130 starts to be injected into the reactor pressure vessel 1 after the accident is equal to Compared to the first embodiment and the second embodiment, the length is shortened and effective for early cooling. The fourth embodiment is shown in FIGS.
This is shown in FIG. 11b. The fourth embodiment is configured by partially changing the configuration of the gravity drop type water injection system of the first embodiment. The partially modified configuration will be described below. The other parts are the same as those of the first embodiment, and the description is omitted.

The gravity drop type water injection system has the configuration described below. That is, the cooling water pool 90 opened to the dry well 11 in the reactor containment vessel 10 and the first cooling water tank 92 provided at a position lower than the cooling water pool 90 are communicated by the first pipe 94. ing. The lower end of the first pipe 94 is immersed in the cooling water in the first cooling water tank 92. The inside of the first cooling water tank 92 and the inside of the reactor pressure vessel 1 are communicated by a third pipe 96. In the middle of the third pipe 96, the first cooling water tank 92
The on-off valve 100 is provided between the reactor pressure vessel 1 and the first check valve 9.
8 are equipped.

The second cooling water tank 91 has a cooling water pool 90.
It is deployed at the same height as. The second cooling water tank 91 and the inside of the reactor pressure vessel 1 are communicated with each other by a second pipe 93.
The on-off valve 99 is provided between the reactor pressure vessel 1 and the second check valve 97.
Is provided.

The third cooling water tank 117 is provided in the cooling water pool 9.
It is deployed at the same height as 0. Fourth cooling water tank 11
4 is provided at the same height as the first cooling water tank 92. The gas phase in the first cooling water tank 92 is communicated with the gas phase in the third cooling water tank 117 by the first pressure equalizing pipe 116. The cooling water in the third cooling water tank 117 communicates with the cooling water in the fourth cooling water tank 114 via a fourth pipe 118. The lower end of the fourth pipe 118 is the fourth cooling water tank 11.
4 is immersed in the cooling water.

The gas phase in the fourth cooling water tank 114 is
The gas pressure section in the cooling water tank 91 is communicated with the pressure equalizing second pipe 95. The cooling water in the fourth cooling water tank 114 is communicated with the inside of the reactor pressure vessel 1 by a fifth pipe 119. In the middle of the fifth pipe 119, a third on-off valve 203 is provided from the fourth cooling water tank 114, and a third check valve 204 is provided from the reactor pressure vessel 1.

The first check valve 98, the second check valve 97, and the third check valve 204 all check to allow the flow in the reactor pressure vessel 1 and prevent the flow in the reverse direction. The direction is determined.

According to the structure of this embodiment, a head pressure from the water surface of the cooling water pool 90 to the water level in the first cooling water tank 92 is applied to the first cooling water tank 92 through the first pipe 94, and the third cooling water tank 117 Has a first pressure equalizing pipe 11
The pressure of the first cooling water tank 92 is applied through 6. In addition to the pressure, the fourth piping 1
18 to the fourth cooling water tank 117 from the water level
A head pressure over the water level in the cooling water tank 114 is applied, and the pressure in the fourth cooling water tank 114 is applied to the second cooling water tank 91 through the equalizing second pipe 95.

For this reason, the injection pressure from the second cooling water tank 91 into the reactor pressure vessel 1 at the time of the accident is determined by the water level in the second cooling water tank 91 and the reactor pressure vessel 1 in the second pipe 93. Between the water head between the water inlet, the water level in the cooling water pool 90, the water level in the first cooling water tank 92, the water level in the third cooling water tank 117, and the water level in the fourth cooling water tank 114. The sum of the head.

As a result, the injection pressure of the present embodiment is significantly increased as compared with the injection pressure at the time of an accident in the gravity drop type injection system of the first embodiment.

In this embodiment, the reactor is operated and
After the pressure in the reactor pressure vessel 1 becomes higher than the injection pressure from the second cooling water tank 91, the first on-off valve 1
00, the second on-off valve 99 and the third on-off valve 203 are opened.

When a cooling water loss accident occurs, the pressure in the reactor pressure vessel 1 decreases as time elapses after the accident, as indicated by the dotted line curve in FIG. 11A, and conversely, the pressure in the dry well 11 increases. And joins the cooling water surface in the cooling water pool 90.

When the pressure in the reactor pressure vessel 1 becomes lower than the injection pressure from the second cooling water tank 91, the second check valve 97 is opened and the cooling water in the second cooling water tank 91 is supplied to the second pipe. It is injected into the reactor pressure vessel 1 through 93. The injection characteristics are as shown by the alternate long and short dash line in FIGS. 11A and 11B. In response to this injection, the cooling water in the cooling water pool 90 flows down into the first cooling water tank 92 through the first pipe 94, and the cooling water in the third cooling water tank 117 flows into the fourth cooling water tank 114. It flows down through the pipe 118.

When the pressure in the reactor pressure vessel 1 further decreases, the first check valve 98 and the second check valve 97 open, and the communication between the first cooling water tank 92 and the fifth cooling water tank is started. Each cooling water is injected into the reactor pressure vessel 1 through the third pipe 96 or the fifth pipe 119. The injection characteristics are shown in FIG.
a, as shown by the two-dot chain line in FIG. 11b.

In this embodiment, the third cooling water tank 117 and the fourth cooling water tank 91 are located between the cooling water pool 90 and the second cooling water tank 91.
Although a configuration in which two tanks are added to the cooling water tank 114 has been shown, it is also conceivable to employ many more cooling water tanks connected in series as in this embodiment. If you choose this idea, you can expect a further increase in water injection pressure. The first cooling water tank 92 is installed at a position lower than the fourth cooling water tank 114, or the fourth cooling water tank 1
If the pump 14 is installed at a position lower than the first cooling water tank 92, the timing of starting water injection from the first cooling water tank 92 and the timing of water injection from the fourth cooling water tank 114 can be relatively shifted. Long-term cooling is possible, and the capacity and installation position of each cooling water tank and cooling water pool 90 must be determined in advance by evaluating the amount of cooling water required for core cooling corresponding to the generation of decay heat of the core. Accordingly, cooling water at an appropriate flow rate can be injected at a plurality of pressure levels, so that the core can be effectively cooled. Subsequent water injection is replaced by a submergence system instead of the gravity drop water injection system, and the long-term water injection continues.

According to the present embodiment, in addition to the benefits obtained by the first embodiment, it is possible to more quickly inject water into the reactor pressure vessel 1 by the gravity drop type water injection system in the event of an accident. Thus, the safety of the reactor is further improved.

In the fourth embodiment, the connection of the second pipe 93, the third pipe 96, and the fourth pipe 119 to the reactor pressure vessel 1 is performed by connecting the second pipe 93, the third pipe 96, and the fourth pipe 119 to each other. Although integrated and connected to one pipe, the second pipe 93 and the third
The pipe 96 and the fourth pipe 119 are individually connected to the reactor pressure vessel 1
The second pipe 93 and the third pipe 93 are connected independently of each other to prevent the water injection from the gravity drop type water injection system into the reactor pressure vessel 1 from being performed at all due to a defect in one of the pipes. This can be avoided by making the water injection passage 96 and the fourth pipe 119 independent of each other up to the reactor pressure vessel 1.

The structure of the fifth embodiment is shown in FIG.

In the fifth embodiment, the configuration of the first embodiment is partially changed, and the configuration of the other parts is the same as that of the first embodiment.
The modified configuration will be described below.

In the first embodiment, two gravity drop type water injection systems are shown. However, the gravity drop type water injection system is housed in a three-system reactor container. Each system of the gravity drop type water injection system is referred to as system A, system B, and system C for convenience. As shown in FIG. 12, the second cooling water tank 91 and the cooling water pool 90 of each system are distributed and provided in the circumferential direction. The cooling water pool 90 is partitioned by a partition plate 120 to make each system independent.

The first cooling water tanks 92 in the systems A, B and C of the gravity drop type water injection system are installed at different heights for each system. Thereby, the potential energy of the cooling water in the first cooling water tank 92 in each system can be made different from each other to diversify the water injection pressure, so that appropriate water injection can be performed according to the pressure change in the reactor pressure vessel 1. Becomes possible.

As an example, by increasing the installation height of the first cooling water tank 92 in the order of the system C, the system B, and the system A, the injection pressure of the second cooling water tank 91 is increased in the systems A, B, and C. , And the first cooling water tank 9 of each system
13 shows a case where the water injection pressure is increased in the order of the system C, the system B, and the system A as shown in FIG. 13A.

In such an example, as the pressure in the reactor pressure vessel 1 decreases after the loss of cooling water, the second cooling water tank 91, The second cooling water tank 91 of the system B, the second cooling water tank 91 of the system C, the first cooling water tank 92 of the system C, the first cooling water tank 92 of the system B, and the first cooling water tank 92 of the system A Cooling water is sequentially injected into the reactor pressure vessel 1 as shown in FIG.

In this case, the amount of cooling water necessary for cooling the core corresponding to the generation of decay heat of the core is evaluated, and the capacity and installation position of each system are determined. Since the cooling water can be injected, the core can be cooled effectively. Subsequent water injection is replaced by a submergence system instead of the gravity drop water injection system, and the long-term water injection continues.

According to the present embodiment, it is possible to inject water into the reactor pressure vessel 1 for a longer period of time by the gravity drop type water injection system at the time of an accident than in the first embodiment, and the safety of the reactor is further improved. .

A sixth embodiment is shown in FIG. Sixth
The second embodiment is different from the first embodiment in that a new configuration is added. The added configuration is as follows.

That is, a first accumulator water injection system and a second accumulator water injection system are added to the first embodiment.

The first accumulator injection system includes a first accumulator injection tank 111 installed on the operation floor 30 in the reactor containment vessel 10.
A first accumulator injection pipe 110 connected from the first accumulator injection tank 111 to an intermediate portion of the second pipe 93;
A first accumulating water injection opening / closing valve 108 provided in the middle of the pressure accumulating water injection pipe 110, and a first accumulator provided in the first accumulating water injection pipe 110 from the reactor pressure vessel 1 similarly to the first accumulating water injection opening / closing valve 108. And a water injection check valve 109.

The second accumulator injection system includes a second accumulator injection tank 20 installed on the operation floor 30 in the containment vessel 10.
A second accumulator injection pipe 24 connected from the second accumulator injection tank 20 into the reactor pressure vessel 1, a second accumulator injection opening / closing valve 81 provided in the middle of the second accumulator injection pipe 24, and a second The second pressure accumulation water injection check pipe 26 is provided in the second pressure accumulation water injection pipe 24 from the reactor pressure vessel 1 rather than the pressure accumulation water injection opening / closing valve 81.

Cooling water is stored in the first pressure accumulation water injection tank 111 and the second pressure accumulation water injection tank 20. The first pressure accumulation water injection tank 111 and the second pressure accumulation water injection tank 20 are filled with gas having a pressure higher than the water injection pressure of the gravity drop type water injection system. Then, a pressure higher than the pressure in the second pressure accumulation water injection tank 20 is applied to the first pressure accumulation water injection tank 111.

In this embodiment, after the reactor is operated and the pressure in the reactor pressure vessel 1 becomes higher than the pressure in the first accumulator injection tank 111, the first accumulator injection valve 10 is opened.
8 and the second accumulator water injection on-off valve 81 are opened.

When a cooling water loss accident occurs, the pressure in the reactor pressure vessel 1 decreases with the passage of time after the accident. When the pressure in the reactor pressure vessel 1 becomes lower than the pressure in the first pressure-accumulating water injection tank 111, the first pressure-accumulating water injection check valve 109 is opened and the first pressure-accumulating water injection is performed prior to the water injection operation by the gravity drop type water injection system. Cooling water in the tank 111 is injected into the reactor pressure vessel 1 through the first accumulator injection pipe 110.

When the pressure in the reactor pressure vessel 1 further decreases after a lapse of time after the accident, the second pressure accumulating water injection check valve 26 is opened, and the cooling water in the second pressure accumulating water injection tank 20 is discharged to the second accumulator. Water is injected into the reactor pressure vessel 1 through the water injection pipe 24.

Further, when the pressure in the reactor pressure vessel 1 further drops after the time after the accident and the pressure in the reactor pressure vessel 1 becomes lower than the injection pressure of the gravity drop type water injection system, the gravity Water injection into the reactor pressure vessel 1 by the falling water injection system is started. The state of water injection in the gravity drop water injection system is the same as in the first embodiment.

FIG. 1 shows the overall water injection characteristics of this embodiment.
6a and FIG. 16b.

According to such water injection characteristics, water injection into the reactor pressure vessel 1 at a point immediately after the accident, which cannot be performed by the gravity drop type water injection system, becomes possible. After the accident, water injection will be performed by the flooding system, and water injection for a long time will continue shortly after the accident.

A seventh embodiment is shown in FIG. In the seventh embodiment, a reinforced concrete structure 16 constitutes a containment vessel. In the reactor containment vessel, a dry well 11 and a wet well 13 are sectioned, and both sections are communicated with a vent pipe 14. Cooling water is contained in the wet well 13 and serves as the suppression pool 12. The outlet of the vent pipe 14 is opened in the cooling water of the suppression pool 12.

In the dry well 11, a reactor pressure vessel 1 containing a reactor core 2 is provided. Cooling water is put in the reactor pressure vessel 1, and the cooling water in the reactor pressure vessel 1 is driven by the internal pump 106 and can pass through the core 2. The cooling water passing through the reactor core 2 is heated by heat from the reactor core 2 and becomes high-temperature and high-pressure steam, passes through the main steam pipe 3, and is supplied to a turbine for rotating a generator as a rotation driving energy source for the turbine. You. The supply passage is a main steam pipe 3, and the main steam pipe 3 extends from the reactor pressure vessel 1 through the reinforced concrete structure 16 to the outside. The water supply pipe 4 is a pipe for returning the liquid used by the steam used in the turbine to the liquid state by the condenser and returning the liquid as cooling water into the reactor pressure vessel 1.
6 and connected to the inside of the reactor pressure vessel 1. The main steam pipe 3 and the water supply pipe 4 are provided with isolation valves for closing those pipes in the event of an accident.

The main steam pipe 3 is connected to an automatic pressure reducing system. The automatic pressure-reducing system includes an automatic pressure-reducing system pipe 143 that communicates between the main steam pipe 3 and the cooling water of the suppression pool 12.
And an automatic pressure reducing valve 23 provided in the middle of the automatic pressure reducing pipe 143.

In the containment vessel 10, a gravity drop type water injection system is provided at a position above the reactor core 2. The gravity drop type water injection system includes a cooling water pool 90 annularly disposed above the reactor containment vessel 10, and a dry well communication passage 10 for communicating a gas phase portion of the cooling water pool 90 into the dry well 11.
4 and a second annularly disposed inside the cooling water pool 90.
A cooling water tank 91, a first cooling water tank 92 annularly disposed at a position lower than the cooling water pool 90 and the second cooling water tank 91, a cooling water in the cooling water pool 90 and a first cooling water tank 92. A first pipe 94 that communicates with the cooling water inside,
A pressure equalizing pipe 95 communicating between the gas phases of the first cooling water tank 92 and the second cooling water tank 91;
A second pipe 93 for communicating the cooling water in the reactor 1 with the inside of the reactor pressure vessel 1, a second on-off valve 99 provided in the middle of the second pipe 93, and a reactor pressure vessel higher than the second on-off valve 99 A second check valve 97 which is provided in the middle part of the second pipe 93 from the first and has a check direction set so as to prevent the flow from the reactor pressure vessel 1 to the second cooling water tank 91 side; A third connecting the cooling water in the cooling water tank 92 with the middle of the second pipe 93.
A pipe 96, a first on-off valve 100 provided in the middle of the third pipe 96, and a third pipe 96 provided in the middle of the second pipe 93 and the first on-off valve 100 are provided from the reactor power vessel to 1
And a first check valve 98 whose check direction is set so as to prevent the flow toward the cooling water tank 92.

In the reactor pressure vessel 1, two accumulator injection systems, a first accumulator injection system and a second accumulator injection system, are further provided.

The first accumulator injection system includes a first accumulator injection tank 111 installed in the dry well 11, and a first accumulator injection pipe 110 connected from the first accumulator injection tank 111 to an intermediate portion of the second pipe 93. And the first accumulator injection pipe 110
A first accumulating water injection opening / closing valve 108 provided in the middle of the first pressure accumulating water injection opening / closing valve 108, and a first accumulating water injection check valve provided in the first accumulating water injection pipe 110 from the reactor pressure vessel 1 more than the first accumulating water injection opening / closing valve 108 109.

The second accumulator injection system includes a second accumulator injection tank 20 installed in the dry well 11, and a second accumulator injection pipe 24 connected from the second accumulator injection tank 20 to the reactor pressure vessel 1. A second pressure accumulation water injection opening / closing valve 81 provided in the middle of the second pressure accumulation water injection pipe 24, and a second pressure accumulation water injection pipe 24 from the reactor pressure vessel 1 more than the second pressure accumulation water injection opening / closing valve 81. And a second accumulator water injection check valve 26. The first accumulator water injection tank 111 and the second
Cooling water is stored in the pressure accumulating water injection tank 20. A pressure higher than the water injection pressure of the gravity drop type water injection system is applied to the first pressure accumulation water injection tank 111 and the second pressure accumulation water injection tank 20. Then, a pressure higher than the pressure in the second pressure accumulation water injection tank 20 is applied to the first pressure accumulation water injection tank 111.

In this embodiment, after the reactor is operated and the pressure in the reactor pressure vessel 1 becomes higher than the injection pressure of the gravity drop type water injection system, the first on-off valve 100 and the second on-off valve 99 Is opened, and after the pressure in the reactor pressure vessel 1 becomes higher than the pressure in the first accumulation water injection tank 111, the first accumulation water injection opening / closing valve 108 and the second accumulation water injection opening / closing valve 81 are opened.

For example, if steam leaks from the main steam pipe 3 into the dry well 11 and a cooling water loss accident occurs, the pressure in the reactor pressure vessel 1 decreases, and conversely, the pressure in the dry well increases. For this purpose, the steam in the dry well is blown into the suppression pool 12 through the vent pipe. The leaked steam is condensed by the cooling water in the suppression pool 12. Further, the automatic pressure reducing valve is opened, and the steam in the reactor pressure vessel 1 is discharged into the cooling water of the suppression pool 12 through the automatic pressure reducing pipe, and the discharged steam is also condensed by the cooling water in the suppression pool 12. The pressure in the reactor pressure vessel 1 decreases with the passage of time after the accident.
When the pressure in the tank is lower than the pressure in the first accumulating water injection tank 111, the first accumulating water injection check valve 109 is opened and the cooling in the first accumulating water injection tank 111 is performed prior to the water injection operation by the gravity drop type water injection system. Water is injected into the reactor pressure vessel 1 through the first accumulator injection pipe 110.

When the pressure in the reactor pressure vessel 1 further drops after the time after the accident, the second pressure accumulation water injection check valve 26 is opened, and the cooling water in the second pressure accumulation water injection tank 20 is discharged to the second pressure accumulation water supply tank 20. Water is injected into the reactor pressure vessel 1 through the water injection pipe 24.

Further, when the pressure in the reactor pressure vessel 1 further decreases after the time after the accident and the pressure in the reactor pressure vessel 1 becomes lower than the injection pressure of the gravity drop type water injection system, gravity occurs for the first time. Water injection into the reactor pressure vessel 1 by the falling water injection system is started. The state of water injection in the gravity drop water injection system is the same as in the first embodiment. That is, first, the cooling water in the second cooling water tank 91 is started to be injected into the reactor pressure vessel 1 through the second check valve 97, and at the same time, the cooling water in the cooling water pool 90 is discharged to the first cooling water pool 90. The first through the pipe 94
It flows down into the cooling water tank 92. Thereafter, since the pressure in the reactor pressure vessel 1 further decreases, the cooling water in the first cooling water tank 92 passes through the first check valve 98 and is injected into the reactor pressure vessel 1.

FIG. 1 shows the overall water injection characteristics of this embodiment.
6a, similar to FIG. 16b.

Since the cooling water in the first pressure accumulation water injection tank 111 and the second pressure accumulation water injection tank 20 is sealed in each tank at a high pressure, the cooling water is supplied to the reactor pressure vessel 1 without using gravity. Can be injected into For this reason, the first pressure accumulation water injection tank 111 and the second pressure accumulation water injection tank 20 are not installed at a high position as in the sixth embodiment, but instead of the gravity-fall type water injection system pools and tanks as in the seventh embodiment. Even if it is installed at a lower position, water injection characteristics similar to those shown in FIGS. 16A and 16B can be obtained, and the degree of freedom in selecting the arrangement positions of the first pressure accumulation water injection tank 111 and the second pressure accumulation water injection tank 20 is high.

FIG. 17 shows an eighth embodiment. In the eighth embodiment, the configuration of the sixth embodiment is partially changed. The other parts except for the partial change are the same as the sixth embodiment. Therefore, the changed portion will be described below.

That is, the first accumulator water injection system of the sixth embodiment is omitted, and a second accumulator water injection system is employed. The configuration of the second accumulator water injection system is the same as that of the second accumulator water injection system in the sixth embodiment.

The gas phase of the cooling water pool 90 communicates with the space on the operating floor 30 in the reactor containment vessel 10 through the hole 105. The pressure applied to the water surface of the cooling water pool 90 is equal to the pressure in the space on the operating floor 30. It is also made up.

After the cooling water loss accident, the operation floor 30
Since the pressure in the space changes slightly lower than the pressure in the dry well 11 space, a gravity-drop type water injection system is used instead of a system in which the dry well 11 space communicates with the gas phase in the cooling water pool 90. Start of water injection tends to be late.
For this reason, in consideration of the continuous connection of water injection between the pressure accumulating water injection system and the gravity drop water injection system, the pressure in the second accumulating water injection tank 20 of the second accumulating water injection system is set lower than that in the sixth embodiment. It is advantageous to eliminate the no-water injection period.

After the start of water injection by the pressure accumulating water injection system, the water injection operation of the gravity drop type water injection system is started, and the water injection operation of the gravity drop type water injection system is the same as in the first embodiment. Then, after the start of water injection of the gravity drop type water injection system, the flooding system takes over the water injection, and performs long-term water injection from an early point after the accident.

The ninth embodiment is an example in which the first accumulator water injection system and the second accumulator water injection system of the sixth embodiment are connected to the structure of the fourth embodiment in a reactor pressure vessel. Also in this example, the injection pressure of each accumulator injection system is higher than the injection pressure of the gravity drop type injection system, and the injection pressure of the first accumulator injection system is higher than that of the second accumulator injection system. Therefore, according to the ninth embodiment, the water injection characteristics are as shown in FIGS. 18A and 18B. In the ninth embodiment, if the vertical relative positions of the first cooling water tank and the fourth cooling water tank are shifted, the cooling water at the position where the start of water injection from the relatively low cooling water tank is relatively high. Water injection characteristics are delayed from the start of water injection into the tank, so that a longer-term cooling water injection operation can be obtained.

The tenth embodiment is different from the fifth embodiment in the sixth embodiment.
It is an example in which the first pressure accumulation water injection system and the second pressure accumulation water injection system of the embodiment are connected in a reactor pressure vessel. Also in this example, each system A,
The water injection pressure of each accumulator water injection system is higher than the water injection pressure of the gravity drop water injection system of B and C, and the water injection pressure of the first accumulator water injection system is higher than that of the second accumulator water injection system. For this reason, according to the ninth embodiment, the water injection characteristics are as shown in FIGS.
9b. 1st accumulator water injection system, 2nd accumulator water injection system,
In each of the systems A, B, and C, the gravity drop type water injection system is configured such that the water injection pressure and the storage flow rate of the cooling water are determined so as to provide continuity in the time when there is no water injection in the middle as shown in FIGS. 19a and 19b. Can be For this reason, in the tenth embodiment, the cooling water injection operation early after the accident and the cooling water injection operation for a long time can be obtained without interruption, and the cooling water having an appropriate flow rate at a plurality of stages of pressure is supplied into the reactor pressure vessel. Water can be injected into the water efficiently.

The eleventh embodiment is shown in FIG.
The eleventh embodiment is a modification of the first embodiment, the second embodiment, and the third embodiment in which a part of the gravity drop type water injection system is changed, and other structures and operations are the same as those of the first embodiment. The structure and operation in the second embodiment and the third embodiment are the same. Therefore, here, the changed part of the gravity drop type water injection system will be described.

The cooling water pool of the gravity drop type water injection system is sealed to form a cooling water storage tank 102. The cooling water in the cooling water storage tank 102 is communicated with the cooling water in the first cooling water tank 92 by the first pipe 94.
The gas phase portion in the cooling water storage tank 102 is connected to the reactor pressure vessel by the first pressure equalization pipe 101. In the middle of the first pressure equalizing pipe 101, a first pressure equalizing on-off valve 1 is provided.
03 is provided.

The other structure is the same as that of any of the first, second and third embodiments.

In the eleventh embodiment, if a cooling water loss accident occurs, the first pressure equalizing on-off valve 103 is opened to equalize the pressure in the reactor pressure vessel 1 and the pressure in the cooling water storage pool 102. .

In this manner, since the pressure in the cooling water storage pool 102 is maintained higher than the pressure in the space of the dry well 11 after the accident, the first pressure applied in the dry well 11 to the cooling water pool is maintained. Example, second example and third example
Water injection into the reactor pressure vessel 1 can be performed earlier after the accident than in the gravity drop type water injection system in the embodiment.

The twelfth embodiment is shown in FIG.
The twelfth embodiment is a modification of the first embodiment, the second embodiment, and the third embodiment, in which a part of the gravity drop type water injection system is changed, and other structures and operations are the same as those of the first embodiment. The structure and operation in any one of the second embodiment and the third embodiment are the same. Therefore, here, the changed part of the gravity drop type water injection system will be described.

In the first, second, and third embodiments, the cooling water pool and the second cooling water tank adjacent thereto are surrounded by a concrete wall provided with a metal liner on the inside. In this embodiment, the cooling water pool and the second cooling water tank adjacent thereto are formed as one cooling water pool, and a part of the cooling water pool withstands the injection pressure so that a part of the cooling water pool becomes the second cooling water tank. A pool sealing portion 107 is formed in a part of the cooling water pool surrounded by a metal wall having the obtained strength, and a metal liner for partitioning the cooling water pool and the second cooling water tank adjacent thereto is provided inside. The cost was reduced by eliminating the concrete wall. A second pipe 93 of the gravity drop type water injection system and a pressure equalizing pipe 95 are connected to the pool sealed portion 107 formed as a part of the cooling water pool so as to have a function as a second cooling water tank,
A first pipe 94 communicating with the first cooling water tank 92 is connected to the other part of the cooling water pool.

The thirteenth embodiment is shown in FIG.
The twelfth embodiment is a modification of the first embodiment, the second embodiment, and the third embodiment, in which a part of the gravity drop type water injection system is changed, and other structures and operations are the same as those of the first embodiment. The structure and operation in any one of the second embodiment and the third embodiment are the same. Therefore, here, the changed part of the gravity drop type water injection system will be described.

The second pipe 93 and the third pipe 96 of the gravity drop type water injection system in the first, second and third embodiments.
Are independently connected into the reactor containment vessel 10.

For this reason, the second pipe 93 and the third pipe 96
Even if it is impossible to inject cooling water into the reactor pressure vessel 1 from one of them due to failure of valves or pipe breakage in either one, it is possible to inject cooling water from the other one A fatal event that water injection from the gravity drop type water injection system into the reactor pressure vessel 1 is completely stopped hardly occurs.

The fourteenth embodiment is shown in FIG.
The fourteenth embodiment is a content obtained by adding a new configuration to the configuration shown in the first embodiment.

The added contents will be described below.

The horizontal partition plate 141 is placed in the wet well 13 in contact with the inner wall surface of the reactor containment vessel 10 at a position higher than the communication hole 18 and at a position corresponding to the height of the water surface of the outer peripheral pool 15. It is provided between the inner wall surface of the container 10 and the concrete structure 16 inside it.

[0219] The gas phase portions of the wet well above the partition plate 141 and the wet well above the partition plate 141 are communicated by the first communication pipe 140, and the gas phase portion of the wet well above the partition plate 141 and the inside of the suppression pool 12 are connected. The cooling water is communicated with the second communication pipe 142.

The other structure is the same as that of the first embodiment.

According to this structure, in addition to the operation of the first embodiment, the non-condensable gas accumulated in the wet well 13 after the loss of the cooling water is vaporized in the wet well above the partition plate 141 due to its low specific gravity. With the first communication pipe 140
Inflow through. At the same time, the steam present in the wet well above the partition plate 141 is released from the reactor containment vessel 1
The 0 wall is indirectly cooled and condensed by air cooling, and the condensed droplets flow down into the suppression pool 12 through the second communication pipe 142 as liquid.

As a result, the steam pressure partial pressure in the wet well 13 decreases, and the pressure decreases. At the same time, the cooling water in the suppression pool 12 is stirred by the liquid that has condensed and flowed down into the suppression pool 12, is in contact with the inner wall surface of the reactor containment vessel 10, is transmitted to the outer peripheral pool 15, and is discharged from the reactor containment vessel 10 The amount of heat to be removed increases, which also lowers the temperature of the cooling water in the suppression pool 12 and reduces the pressure.

As a result, the difference between the pressure in the reactor pressure vessel 1 and the pressure in the reactor containment vessel 10 is increased, and the pressure in the reactor pressure vessel 1 is reduced by the automatic pressure reducing system. Cooling water can be injected from the cooling water tank 91 into the reactor pressure vessel 1 at an early stage.

The fifteenth embodiment is shown in FIG. The fifteenth embodiment is different from the second embodiment in that the cooling water second pool 130 is used.
Instead of a gravity drop type water injection system using a water injection water source, a gravity drop type water injection system having a configuration shown in FIG. 24 is employed. Other configurations are the same as those of the second embodiment.

The structure of the gravity drop type water injection system shown in FIG. 24 and the operation performed by the system are as follows.

That is, the cooling water storage tank 130 is provided in the reactor containment vessel 10 and above the reactor core. When the pressure in the cooling water storage tank 130 reaches a set pressure, the cooling water storage tank 130 releases the pressure from the gas phase in the cooling water storage tank 130 into the dry well 11.
6 is provided as exhaust pressure limiting means. The set pressure at which the safety valve 146 is opened is defined as the pressure limit pressure of the cooling water storage tank 130, and a pressure lower than that pressure is discharged from the cooling water storage tank 130 to the outside so as to remain in the cooling water storage tank 130. Is limited by the safety valve 146.

Cooling water storage tank 130 and dry well 1
1 is communicated with an air supply pipe 144 having an air supply check valve 145 on the way. The air supply check valve 145 is set to have a check direction so as to allow the flow from the dry well 11 into the cooling water storage tank 130 and to prevent the flow in the opposite direction.

The inside of the cooling water storage tank 130 and the inside of the reactor pressure vessel 1 communicate with each other through a water injection pipe 123 having a water injection opening / closing valve 205 and a water injection check valve 124. Water injection check valve 124
Sets the non-return direction so as to allow the flow from the cooling water storage tank 130 into the reactor pressure vessel 1 and prevent the flow in the reverse direction.

The exhaust port of the automatic pressure reducing system pipe 143 of the automatic pressure reducing system connected to the main steam pipe 3 is connected to the cooling water storage tank 130.
Submerged in the cooling water inside.

In the above configuration, when the reactor is operated and the pressure in the reactor pressure vessel 1 is
After the temperature of the cooling water in the chamber 0 has reached a level that can be prevented from flowing into the reactor pressure vessel 1, the water injection on-off valve 205 is opened.

In the event of a loss of cooling water, the automatic pressure reducing valve 23 of the automatic pressure reducing system is opened, and the steam in the reactor pressure vessel 1 is discharged into the cooling water in the cooling water storage tank 130 through the automatic pressure reducing system piping 143. . The steam released into the cooling water in the cooling water storage tank 130 is condensed by the cooling water, and the volume of the atmosphere containing the released steam is reduced immediately after the release. Therefore, the pressure limit of the cooling water storage tank 130 can be reduced as compared with the case where the volume of the atmosphere containing the released steam is directly discharged into the gas phase portion in the cooling water storage tank 130 having no condensation function. The lowering of the pressure resistance limit of the cooling water storage tank 130 can reduce the cost.

The steam released into the cooling water in the cooling water storage tank 130 is condensed by the cooling water, and the cooling action raises the temperature of the cooling water in the cooling water storage tank 130 by the condensation action. Then, the pressure in the cooling water storage tank 130 increases due to the increase in the vapor pressure.

When the sum of the pressure in the cooling water storage tank 130 and the hydrostatic head extending from the surface of the cooling water in the cooling water storage tank 130 to the inside of the reactor pressure vessel 1 becomes higher than the pressure in the reactor pressure vessel 1, a water injection check valve is provided. 124 is opened, and the cooling water in the cooling water storage tank 130 is injected into the reactor pressure vessel 1.
The water injection pressure at this time is much higher than in the case where there is no pressure increase due to the above-mentioned steam pressure, so that water can be injected into the reactor pressure vessel 1 at an early stage.

The timing of starting the injection of water from the gravity drop type water injection system into the reactor pressure vessel 1 according to FIG. 24 is earlier than the timing of starting the injection of cooling water from the second cooling water tank into the reactor pressure vessel 1 in FIG. For the cooling water storage tank 1
It is desirable that the pressure in the cooling water tank 30 be higher than the pressure in the second cooling water tank. Therefore, the amount of the cooling water stored in the cooling water storage tank 130 and the size of the cooling water storage tank 130 should be determined. .

If the pressure in the cooling water storage tank 130 tries to exceed the pressure resistance limit of the cooling water storage tank 130,
The safety valve 146 is opened to release the pressure in the cooling water storage tank 130 to the outside of the cooling water storage tank 130 to measure the safety of the cooling water storage tank 130.

When the cooling water in the cooling water storage tank 130 is injected into the reactor pressure vessel 1, the cooling water storage tank 13
When the cooling water level in the cooling water storage tank 130 decreases and the pressure in the cooling water storage tank 130 starts to decrease, the air supply check valve 14
5 is opened and the atmosphere in the dry well 11 is changed to the air supply pipe 14.
Air is supplied into the cooling water storage tank 130 through the inside of the cooling water storage 4, and the tendency of negative pressure in the cooling water storage tank 130 is suppressed. After the start of water injection from the cooling water storage tank 130, the gravity drop type water injection system of the second embodiment starts water injection, and thereafter, the flooding system starts water injection.

The other contents are the same as in the second embodiment.

The sixteenth embodiment is shown in FIG. The sixteenth embodiment is a partial modification of the fifteenth embodiment, and the other parts are the same as the fifteenth embodiment. Hereinafter, the content of the partially changed portion will be described.

In the cooling water in the cooling water storage tank 130, a condenser 135 is provided in contact with the cooling water. The inside of the condenser 135 and the exhaust port of the automatic pressure reducing pipe 143 are connected.

The upper end of the return pipe 138 is connected to the condensate storage area in the condenser 135, and the lower end of the return pipe 138 is placed in the cooling water in the suppression pool 12.

The other construction is the same as that of the fifteenth embodiment.

In this embodiment, after the loss of the cooling water, the high-temperature and high-pressure steam in the reactor pressure vessel 1 passes through the main steam pipe 3, the automatic pressure reducing valve 23 and the automatic pressure reducing pipe 143,
5 flows into. The steam flowing into the condenser 135 is cooled by the cooling water in the cooling water storage tank 130 via the heat transfer surface of the condenser 135 and condensed. The liquid condensed in the condenser 135 and returned from the vapor state to the liquid state is returned as cooling water to the suppression pool 12 through the return pipe 138.

The condensation of the condenser 135 causes the condenser 13
5, the cooling water in the cooling water storage tank 130 is heated by the thermal energy imparted to the cooling water in the cooling water storage tank 130, the vapor pressure in the cooling water storage tank 130 increases, and the cooling water storage tank 130 The pressure inside rises.

When the pressure in the cooling water storage tank 130 rises in this way, the cooling water in the cooling water storage tank 130 can be quickly injected into the reactor pressure vessel 1 as in the fifteenth embodiment.

The other contents are the same as in the fifteenth embodiment.

In the sixteenth embodiment, unlike the fifteenth embodiment, the steam in the reactor pressure vessel 1 is condensed in the condenser 135 and only heat energy is applied to the cooling water storage tank 130. As compared with the fifteenth embodiment in which the steam is directly discharged into the cooling water storage tank 130,
It is easy to prevent abnormal pressurization of the cooling water storage tank 130 when the amount of steam flowing through 43 is extremely large.

Furthermore, since the steam in the reactor pressure vessel 1 and the cooling water in the cooling water storage tank 130 can be isolated via the condenser 135, the cooling water storage tank 130 can be separated from the reactor containment vessel 10. Installation becomes possible, and the degree of freedom in the design of reactor equipment is expanded. Cooling water storage tank 130
Can be installed outside the reactor containment vessel 10, the capacity of the cooling water storage tank 130 is reduced to the dry well 11.
Can be increased without being affected by the size of the inside.

The seventeenth embodiment is shown in FIG. The seventeenth embodiment is a partial modification of the gravity drop type water injection system of the first embodiment, and the other parts are the same as the first embodiment. Therefore, how the partially changed contents will be described.

The cooling water pool according to the first embodiment is closed to form a cooling water tank 102. In the cooling water in the cooling water tank 102, an exhaust port of the automatic pressure reducing pipe 143 is provided. The cooling water tank 102 is provided with a safety valve 146.
2 and the inside of the dry well 11 can communicate with each other. Further, the cooling water tank is equipped with an air supply check valve 145.

The air supply check valve 145 has a check direction which allows the flow from the inside of the dry well 11 into the cooling water tank 102 and prevents the flow in the opposite direction.

The safety valve is set at a set pressure at which the opening operation is performed so that the cooling water tank 102 opens at the pressure of the pressure resistance limit.

The other contents are the same as in the first embodiment.

In the present embodiment, in the event of a cooling water loss accident, the steam in the reactor pressure vessel 1 is released by the automatic pressure reducing valve 23 through the automatic pressure reducing system piping 143 into the cooling water in the cooling water tank 102. Is condensed by cooling water. As a result, the temperature of the cooling water in the cooling water tank 102 increases, and the pressure in the cooling water tank 102 increases due to an increase in the vapor pressure in the cooling water tank 102.

The sum of the pressure in the cooling water tank 102 and the sum of the hydrostatic head extending from the cooling water level in the cooling water tank 102 to the first cooling water tank 92 is applied to the second cooling water tank 91 as pressure.

From the hydrostatic head extending from the second cooling water tank 91 to the inside of the reactor pressure vessel 1, the pressure in the cooling water tank 102, and the cooling water level in the cooling water tank 102, the first cooling water tank 9
When the sum of the two hydrostatic heads becomes higher than the pressure in the reactor pressure vessel 1, the cooling water in the second cooling water tank 91 is injected into the reactor pressure vessel 1.

At this time, the injection pressure is much higher than when the temperature of the cooling water in the cooling water tank does not rise. Therefore, it is possible to inject cooling water into the reactor pressure vessel 1 at an early stage. Further, when the injection of water from the second cooling water tank 91 into the reactor pressure vessel 1 is started, the cooling water in the cooling water tank 102 falls into the first cooling water tank 92, and the cooling water is also cooled to the reactor pressure. Water is poured into the container 1.

An eighteenth embodiment is shown in FIG. The eighteenth embodiment is obtained by partially changing the configuration of the sixteenth embodiment, and the other parts are the same as the fifteenth embodiment. The partially changed contents will be described below.

The cooling water storage tank 130 is not provided with the air supply check valve 145 and the safety valve 146 in the fifteenth embodiment.
Is open. The breathing hole 147 communicates the gas phase in the cooling water storage tank 130 with the inside of the dry well 11.

The other structure is the same as that of the fifteenth embodiment.

In this embodiment, after the loss of the cooling water, the automatic pressure reducing valve 23 is opened, and the high-temperature and high-pressure steam in the reactor pressure vessel 1 is filled in the cooling water storage tank 130 with the automatic pressure reducing system piping 14.
Supplied through 3. The steam is the cooling water storage tank 1
When supplied to the cooling water in the cooling water 30, the steam is condensed by the cooling water, and the cooling water in the cooling water storage tank 130 is heated and evaporated, and the vapor pressure increases. Cooling water storage tank 1
The pressure in the cooling water storage tank 130 is heated more than the pressure in the cooling water storage tank 130 decreases due to the pressure in the cooling water storage tank 130 dropping out of the breathing hole 147 to the dry well 11. The opening area of the breathing hole 147 is determined so that the increasing speed of the pressure that increases with the pressure becomes faster.

For this reason, the breathing hole 147 is provided so that a part of the pressure generated in the cooling water storage tank 130 is exhausted and the other part remains in the cooling water storage tank 130. It is adopted as a means for restricting discharge to the outside of 130, that is, a discharge pressure restricting means. Therefore,
The pressure in the cooling water storage tank 130 will increase based on the difference between the pressure continuously generated in the cooling water storage tank 130 and the pressure discharged from the breathing hole 147.

For this purpose, the cooling water injection operation from the cooling water storage tank 130 into the reactor pressure vessel 1 simply employs a method in which the pressure inside the cooling water storage tank 130 is made equal to the pressure inside the dry well 11. Obtained earlier than the ones.

The nineteenth embodiment is shown in FIG. The nineteenth embodiment is an example in which a part of the fifteenth embodiment is changed, and the other parts are the same as the fifteenth embodiment. Therefore, the partially changed contents will be described.

The safety valve of the fifteenth embodiment does not exist, and a vent pipe 148 is used instead. The outer periphery of the vertical vent pipe 148 is hermetically attached to the cooling water storage tank 130 in the middle thereof. Vent pipe 14
The upper end opening 8 opens into the dry well 11.
The lower end opening of the vent pipe 148 opens into the cooling water in the cooling water storage tank 130.

The other structure is the same as that of the fifteenth embodiment.

Also in the nineteenth embodiment, after the loss of the cooling water, the automatic pressure reducing valve 23 is opened, and the steam in the reactor pressure vessel 1 is released into the cooling water in the cooling water storage tank 130 through the automatic pressure reducing system piping 143, and there. Condensed. At the same time, the cooling water in the cooling water storage tank 130 is heated and evaporates. The pressure in the cooling water storage tank 130 is increased by the vaporized steam, and the cooling water level in the cooling water storage tank 130 is pushed down. For this reason, the operation of injecting the cooling water in the cooling water storage tank 130 into the reactor pressure vessel 1 is more effective than simply adopting a method in which the pressure in the cooling water storage tank 130 is made equal to the pressure in the dry well 11. , Obtained early.

When the pressure in the cooling water storage tank 130 rises, the surface of the cooling water in the vent pipe is pushed up, and the pressure in the cooling water storage tank 130 is substantially discharged and relieved. The pressure remains in the cooling water storage tank 130 by an amount corresponding to the head difference pressure between the cooling water level outside the vent pipe. Therefore, in this embodiment, a vent pipe is employed as the exhaust pressure limiting means.

[0268]

According to the first aspect of the present invention, the water injection pressure of the gravity drop type water injection system can be increased without depending on the existing water injection pressure increasing means. The effect of improving both properties is obtained.

According to the second aspect of the invention, the effect of the first aspect of the invention can be achieved with a simple configuration in which a plurality of tanks are connected by a flow path.

[0270]

[0271]

[0272]

[0273]

[0274]

[0275]

[0276]

According to the invention of claim 3, claim 1 or contract
In addition to the effect of the invention of claim 2, by equalizing the pressure applied to the water surface of the cooling water pool with the pressure in the dry well that was increased at the time of the accident, the effect that the injection start timing can be shifted earlier. can get.

According to the fourth aspect of the invention , the effect of the first aspect of the invention can be achieved by the thermal energy generated in the reactor pressure vessel, and it is not necessary to newly provide a thermal energy source. Can be

[0279]

[0280]

[0281]

[0282]

[0283]

According to the fifth aspect of the present invention , since the potential energy of water is changed to the pressurized pressure and used for the water injection pressure, the economy and safety of the reactor equipment including the reactor cooling device can be improved. The effect is obtained.

According to the sixth aspect of the present invention , there is obtained an effect that it is possible to provide a pressurized cooling water supply means which can contribute to improving the economy and safety of nuclear reactor equipment by utilizing the potential energy of water. Can be

According to the seventh aspect of the present invention , there is obtained an effect that it is possible to provide a means for pressurizing injected cooling water which can contribute to improving the economy and safety of nuclear reactor equipment by utilizing thermal energy.

[0287] According to the invention of claim 8, the water injection start timing of the gravity drop type water injection system is dispersed between the high pressure side and the low pressure side so that flexibility is provided during the water injection period of the gravity drop type water injection system.
Coordination with water injection by the submergence system is also good, so that it is suitable for long-term cooling, and furthermore, it is possible to provide a reactor facility with improved economy and safety.

According to the ninth aspect of the invention , the water injection start timing of the gravity drop type water injection system is dispersed between the high pressure side and the low pressure side so that flexibility is provided during the water injection period of the gravity drop type water injection system.
Coordination with water injection by the accumulator water injection system is also good, so that it is suitable for long-term cooling, and furthermore, it is possible to provide an advantageous effect that it is possible to provide a reactor facility with improved economy and safety.

According to the tenth aspect of the present invention , the water injection start timing of the gravity drop type water injection system is dispersed between the high pressure side and the low pressure side so that flexibility is provided during the water injection period of the gravity drop type water injection system. Long-term cooling with good coordination between water injection by a pressure accumulating water injection system that also has a high water injection pressure and water injection by a flooded water system that also has a low water injection pressure. In addition to the above, it is possible to provide a nuclear reactor facility with improved economy and safety.

[0290]

[0291]

[0292]

[0293]

[0294]

[0295]

According to the eleventh aspect of the present invention, it is possible to provide a method in which the water injection operation area of the gravity drop water injection system is expanded to the high pressure side and the low pressure side so that the gravity drop water injection system can perform early and long-term water injection. can get.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a nuclear reactor facility according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a reactor facility according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a reactor facility according to a third embodiment of the present invention.

FIG. 4 is a conceptual diagram of a gravity drop type water injection system in a water injection standby state in each of the first, second, and third embodiments of the present invention.

FIG. 5 is a conceptual diagram of a gravity drop type water injection system in an initial state of water injection in each of the first, second, and third embodiments of the present invention.

FIG. 6 is a conceptual diagram showing a state of the gravity drop type water injection system in the latter half of the start of water injection in each of the first, second, and third embodiments of the present invention.

FIG. 7 is a conceptual diagram illustrating a state after completion of water injection of a gravity drop type water injection system in each of the first, second, and third embodiments of the present invention.

FIG. 8 (a) shows water injection characteristics of a gravity drop type water injection system in each of the first, second and third embodiments of the present invention;
It is a graph showing the relationship between the elapsed time after the accident and the injection pressure. (B) shows the water injection characteristics of the gravity drop type water injection system in each of the first, second and third embodiments of the present invention, and is a graph showing the relationship between the elapsed time after the accident and the water injection flow rate. is there.

FIG. 9 is a system diagram of a gravity drop type water injection system showing a modified example of the gravity drop type water injection system of the first embodiment of the present invention.

FIG. 10 is a system diagram of a gravity drop type water injection system according to a fourth embodiment of the present invention.

FIG. 11A is a graph showing a water injection characteristic of a gravity drop type water injection system according to a fourth embodiment of the present invention, and is a graph showing a relationship between elapsed time after an accident and water injection pressure. (B)
FIG. 9 is a graph showing water injection characteristics of a gravity drop type water injection system according to a fourth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection flow rate.

FIG. 12 is a cross-sectional view of a reactor facility according to a fifth embodiment of the present invention.

FIG. 13A is a graph showing water injection characteristics of a gravity drop type water injection system according to a fifth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection pressure. (B)
FIG. 8 is a graph showing water injection characteristics of a gravity drop type water injection system according to a fifth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection flow rate.

FIG. 14 is a longitudinal sectional view of a reactor facility according to a sixth embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a reactor facility according to a seventh embodiment of the present invention.

FIG. 16 (a) is a graph showing water injection characteristics of a gravity drop type water injection system according to a sixth embodiment of the present invention, and is a graph showing a relationship between elapsed time after an accident and water injection pressure. (B)
FIG. 10 is a graph showing water injection characteristics of a gravity drop type water injection system according to a sixth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection flow rate.

FIG. 17 is a longitudinal sectional view of a reactor facility according to an eighth embodiment of the present invention.

FIG. 18 (a) is a graph showing water injection characteristics of a gravity drop type water injection system according to a ninth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection pressure. (B)
FIG. 9 is a graph showing water injection characteristics of a gravity drop type water injection system according to a ninth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection flow rate.

FIG. 19A is a graph showing water injection characteristics of a gravity drop type water injection system according to a tenth embodiment of the present invention, and is a graph showing a relationship between elapsed time after an accident and water injection pressure. (B)
FIG. 10 is a graph showing water injection characteristics of a gravity drop type water injection system in a tenth embodiment of the present invention, and showing a relationship between elapsed time after an accident and water injection flow rate.

FIG. 20 is a system diagram of a gravity drop type water injection system according to an eleventh embodiment of the present invention.

FIG. 21 is a system diagram of a gravity drop type water injection system according to a twelfth embodiment of the present invention.

FIG. 22 is a system diagram of a gravity drop type water injection system according to a thirteenth embodiment of the present invention.

FIG. 23 is a longitudinal sectional view of a nuclear reactor facility according to a fourteenth embodiment of the present invention.

FIG. 24 is a system diagram of a gravity drop type water injection system according to a fifteenth embodiment of the present invention.

FIG. 25 is a system diagram of a gravity drop type water injection system according to a sixteenth embodiment of the present invention.

FIG. 26 is a system diagram of a gravity drop type water injection system according to a seventeenth embodiment of the present invention.

FIG. 27 is a system diagram of a gravity drop type water injection system according to an eighteenth embodiment of the present invention.

FIG. 28 is a system diagram of a gravity drop type water injection system according to a nineteenth embodiment of the present invention.

[Explanation of symbols]

1 ... Reactor pressure vessel, 2 ... Core, 3 ... Main steam piping, 4 ...
Water supply piping, 10: reactor containment vessel, 11: dry well, 12: suppression pool, 13: wet well, 15: outer peripheral pool, 16: concrete structure, 1
7 ... vent pipe, 18 ... communication hole, 20 ... second accumulator injection tank, 23 ... automatic pressure reducing valve, 24 ... second accumulator injection pipe, 26
... second pressure accumulating water injection check valve, 30 ... operating floor, 31 ... pressure release plate, 32 ... air intake, 33 ... air cooling duct, 83 ... submergence opening / closing valve, 84 ... submergence piping, 85 ... submergence reverse Stop valve,
87 ... exhaust duct, 90 ... cooling water pool, 91 ... second cooling water tank, 92 ... first cooling water tank, 93 ... second pipe, 94 ... first pipe, 95 ... equalizing pipe, 96 ... Third pipe, 97: second check valve, 98: first check valve, 99: second
On-off valve, 100: first on-off valve, 101: first equalizing pipe, 102: cooling water storage tank, 103: first equalizing on-off valve, 104: drywell communication passage, 105: hole, 10
7 ... Pool closed part, 108 ... First accumulator water injection on-off valve, 10
9: first accumulator water injection check valve, 110: first accumulator water injection pipe,
111: first accumulator injection tank, 114: fourth cooling water tank, 116: equalizing first piping, 117: third cooling water tank, 118: fourth piping, 119: fifth piping, 120: partition plate, 122: water injection on-off valve, 123: water injection pipe, 124
... water injection check valve, 130 ... cooling water second pool, 134 ... dry well second communication path, 135 ... condenser, 136 ... vent pipe, 137 ... condenser opening and closing valve, 138 ... condensed water piping, 1
39: condenser pipe, 140: first communication pipe, 141: partition plate, 142: second communication pipe, 143: automatic pressure reducing system pipe, 144: air supply pipe, 145: air supply check valve, 146 ...
Safety valve, 147: tank breathing hole, 148: vent pipe.

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yoshiyuki Kataoka 1168 Moriyama-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Energy Research Laboratories (72) Michio Murase 1168 Moriyama-machi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Energy Research In-house (58) Field surveyed (Int. Cl. ⁷ , DB name) G21C 15/18 G21C 9/004

Claims (11)

(57) [Claims] 1. A first means for converting potential energy based on a water level difference or thermal energy added to water when water injection is required into gaseous phase pressure, and the gas pressure by said means is supplied to a reactor pressure vessel via a valve. And a second means for applying the cooling water to a cooling water tank located at a position higher than the reactor core position. 2. The first cooling water tank according to claim 1, wherein the first cooling water tank is located below a water level in the cooling water pool, and a liquid phase portion of the cooling water pool communicates with the inside of the first cooling water tank. A first means having a first flow path; and a communication path provided between a gas phase portion of the first cooling water tank and a second cooling water tank higher than the first cooling water tank. A reactor cooling system comprising: a second means provided; and a second flow path connecting a liquid phase part in the second cooling water tank and the inside of the reactor pressure vessel via a valve. 3. The reactor cooling system according to claim 1, wherein the cooling water pool is opened in a dry well region in the reactor containment vessel. 4. A cooling water tank for storing cooling water, and means for adding heat generated in the reactor pressure vessel to the cooling water in the cooling water tank as a first means,
A reactor cooling apparatus comprising: a second means including a discharge pressure limiting means for suppressing a pressure shift between the cooling water tank and the inside and outside of the cooling water tank. 5. The method according to claim 5, wherein the water located at a high place is a liquid tank located at a lower place.
Means for converting the potential energy with respect to the water level in the tank to the pressure of the gas phase in the liquid tank at a low place, and cooling for adding the pressure of the gas phase by the means as water injection pressure into the reactor pressure vessel A reactor cooling device including a water injection system. 6. A system for applying a hydrostatic head pressure difference between a pool and a tank, which are communicated with each other and arranged at two high and low places, to a gas phase part in the tank at the low place, and a pressure of the gas phase part. A pressurizing device for supplying cooling water with a system for applying the cooling water to a cooling water tank for storing the cooling water. 7. A cooling water tank for storing cooling water for cooling water, and means for converting thermal energy into a gas phase pressure of a gas phase portion in the cooling water tank using the cooling water for cooling water as a medium. Pressurizing device. 8. A reactor pressure vessel having a built-in reactor core, a suppression pool for condensing steam generated in the reactor pressure vessel at the time of an accident, and a valve for supplying pool water of the suppression pool located higher than the core. Submergence system communicably connected to the reactor pressure vessel through a gravitational drop type water injection system disposed higher than the suppression pool and communicably connected to the reactor pressure vessel via a valve A cooling water pool, and a reactor containment vessel for storing the above-mentioned configuration, wherein the gravity drop water injection system is provided with a first cooling water tank located below a water level in the cooling water pool. A first flow path that communicates a liquid phase portion of the cooling water pool with the inside of the first cooling water tank;
A communication passage provided between a gas phase part of the cooling water tank and a second cooling water tank higher than the first cooling water tank;
A second flow path connecting the liquid phase portion in the second cooling water tank and the inside of the reactor pressure vessel via a valve, and cooling the first cooling water tank and the inside of the reactor pressure vessel via a valve; A reactor facility comprising a third flow path for communicating water. 9. A reactor pressure vessel having a built-in reactor core, a suppression pool for condensing steam generated in the reactor pressure vessel at the time of an accident, and a reactor disposed at a higher elevation than the reactor core through a valve. A cooling water pool of a gravity drop type water injection system communicably connected to the pressure vessel, and a water pressure of the gravity drop type water injection system, which is communicably connected to the reactor pressure vessel via a valve, and In a reactor facility including a high-pressure tank of a pressure accumulating water injection system in which cooling water is sealed at a high pressure, and a reactor containment vessel that stores the above-described configuration, the gravity drop water injection system includes a water level in the cooling water pool. A first cooling water tank also located below, a first flow path communicating the liquid phase portion of the cooling water pool with the inside of the first cooling water tank, a gas phase portion of the first cooling water tank, No. 1 in a higher place than the first cooling water tank A communication passage provided between the cooling water tank, a second flow path connecting a liquid phase part in the second cooling water tank and the inside of the reactor pressure vessel via a valve, Reactor equipment comprising a water tank, a third flow passage for communicating cooling water via a valve and the inside of the reactor pressure vessel. 10. A reactor pressure vessel having a built-in reactor core, a suppression pool for condensing steam generated in the reactor pressure vessel at the time of an accident, and a valve located above the reactor core and provided with pool water of the suppression pool. Submergence system communicably connected to the reactor pressure vessel through a gravitational drop type water injection system disposed higher than the suppression pool and communicably connected to the reactor pressure vessel via a valve A cooling water pool, and a high-pressure tank of a pressure accumulating water injection system, which is connected to be able to communicate with the reactor pressure vessel via a valve, and in which cooling water is sealed at a higher pressure than the injection pressure of the gravity drop type water injection system. In a nuclear reactor equipped with a reactor containment vessel that stores these configurations, the gravity drop water injection system includes:
A first cooling water tank located below a water level in the cooling water pool, a first flow path communicating a liquid phase part of the cooling water pool with the inside of the first cooling water tank, A communication passage provided between a gas phase part of the water tank and a second cooling water tank higher than the first cooling water tank; a liquid phase part in the second cooling water tank and a reactor pressure; A second flow path connecting the inside of the reactor via a valve, and a third passage for communicating the cooling water through a valve with the first cooling water tank and the reactor pressure vessel.
A nuclear reactor facility comprising a flow path. 11. A water storage area of a gravity drop type water injection system for a reactor pressure vessel is provided at least at both high and low places and other places higher than the low water storage area, and each of the high and low water storage areas is provided. Pressurizing the gaseous phase portion of the water storage area at the low place with a head pressure difference between the two, applying the pressure of the gaseous phase section to the water storage area at the other place, A method of injecting water from a gravity drop type water injection system, wherein the timing of starting water injection from the water storage region is shifted to a high pressure side, and the timing of starting water injection from the low water storage area is shifted to a low pressure side.