JP2000180582A - Reactor power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of reactor building and material weight by removing a cooling water pool of a passive containment cooling system and an emergency condenser. SOLUTION: A fuel pool 8 and a component pit 9 are connected with a communication pipe 13. A heat exchanger 5 for containment cooling equipment is placed in the fuel pool 8, one side of a steam supply pipe 6 for containment cooling equipment is connected to the inlet side of the heat exchanger 5 and one end of a condensate return pipe 7 is connected to the outlet side of the heat exchanger 5. The other end of the steam supply pipe 6 is opened to a containment 3 and the other end of the condensate return pipe 7 is connected to the reactor pressure vessel 1. The heat exchanger 5 is cooled with a plenty of water in the fuel pool 8 and the component pit 9 connected with the communication pipe 13 in early period of event generation and then the heat is transported with the cooling system of the fuel pool 8 to a terminal heat sink. By this, a conventional cooling water pool can be removed and so reduction of size and material weight of reactor building is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear power plant having a containment heat removal facility or an emergency condenser for removing decay heat of a nuclear reactor.

[0002]

2. Description of the Related Art In a nuclear power plant, steam generated by a transient event or decay heat after an accident and leaked into a containment vessel is guided to a heat exchanger in a cooling water pool water installed outside the containment vessel, and the pool water is used as a heat sink. FIG. 9 shows a first example of a conventional nuclear power plant having a containment heat removal facility having a function of removing decay heat in a containment vessel by condensing steam by a heat transfer surface in a heat exchanger. Show.

The nuclear power plant is provided with an airtight containment vessel 3 surrounding the reactor pressure vessel 1 in order to suppress the release of radioactive materials into the atmosphere in the event of a coolant loss accident. The reactor pressure vessel 1 has a reactor internal structure 2 disposed therein, and an upper end opening is provided at the reactor pressure vessel head 4.
Sealed.

[0004] Containment vessel heat removal equipment is provided to remove long-term decay heat after the accident outside the containment vessel. The containment vessel heat removal equipment is provided with a cooling water pool 19 for the containment vessel heat removal equipment installed outside the containment vessel 3, a heat exchanger 5 using the cooling water pool 19 as a heat sink, and a decay heat in the containment vessel 3. A steam supply pipe 6 for guiding the steam to the heat exchanger 5, and a condensate return pipe 7 for returning the condensed water cooled and condensed by the heat exchanger 5 back into the containment vessel 3.

Next, the operation of the heat removal equipment for the containment vessel will be described. When a coolant loss accident occurs in the containment vessel 3 due to a pipe break, the reactor scrams, but steam generation due to decay heat continues. The generated steam is released into the containment vessel 3 through the break, is guided to the heat exchanger 5 for the containment heat removal equipment by the steam supply pipe 6, and is condensed by the heat removal in the cooling water pool 19 to be condensed. The water is returned into the storage container 3 again by the condensate return pipe 7.

The temperature of the water in the cooling water pool 19 rises due to the heat transmitted from the heat exchanger 5, and finally the water boils and is vented to the atmosphere. The installation height of the PCV heat removal equipment is higher than the reactor pressure vessel 1, and steam and condensate circulate by natural circulation due to the density difference without depending on external power to remove decay heat. .

As a second example of a nuclear power plant, as shown in FIG. 10, when the reactor is isolated, steam generated by decay heat after shutdown in the reactor pressure vessel 1 is used for emergency use. The cooling water for the condenser equipment pool 20 is led to the heat exchanger 15 for the emergency condenser equipment in the water, and the pool water is used as a heat sink to condense the steam by the heat transfer surface in the heat exchanger 15 so that the reactor pressure is reduced. A nuclear power plant having an emergency condenser for cooling a core in a vessel 1 is known.

In this nuclear power plant, an emergency condenser is provided for removing decay heat outside the containment vessel 3 when the reactor pressure vessel 1 is isolated as described in detail. This emergency condenser was generated by the decay heat inside the containment vessel 3 and the heat exchanger 15 for the emergency condenser equipment using the emergency condenser cooling water pool 20 installed outside the containment vessel 3 as a heat sink. A steam supply pipe 16 for guiding the steam to the heat exchanger 15 for the emergency condenser equipment of the PCV heat removal equipment, and the condensate cooled and condensed by the heat exchanger 15 is returned to the reactor pressure vessel 1 again. It consists of a condenser condenser return pipe 17.

Next, the operation of the emergency condenser in the nuclear power plant of the second example will be described. When an abnormal transient change occurs in the nuclear power plant, a main steam isolation valve (not shown) closes, the reactor is isolated and scrams, but steam generation due to decay heat continues. The steam generated in the reactor pressure vessel 1 is guided to the heat exchanger 15 for the emergency condenser equipment by the steam supply pipe 16, condensed by removing heat in the cooling water pool 20, condensed, and condensed. It is returned to the reactor pressure vessel 1 by 17 again.

The temperature of the water in the cooling water pool 20 rises due to the heat transmitted from the heat exchanger 15 and finally boils and vents into the atmosphere. The installation height of the PCV heat removal equipment is higher than the reactor pressure vessel 1, and steam and condensate circulate by natural circulation due to the density difference without depending on external power to remove decay heat. .

On the other hand, the nuclear power plant is provided with a fuel pool 8 for storing a fuel rack 12 for spent fuel or replacement fuel above the reactor, and is always cooled by a fuel pool cooling system 10. A fuel pool replenishing water system 11 for replenishing water in the fuel pool 8 is also provided.

In the nuclear power plant, an equipment pit 9 for storing the head portion 4 of the reactor pressure vessel 1 and the reactor internals 2 under water above the reactor when fuel in the reactor core is replaced. Is provided. This equipment pit is drained and empty during normal operation.

[0013]

However, in the conventional heat removal equipment for the containment vessel or the emergency condenser, the heat exchanger 5 is used.
Alternatively, it is necessary to provide a large-scale cooling water pool 19 or 20 for cooling the reactor 15, which causes a problem that the reactor building becomes large. Also, although the equipment pit 9 is a large pool, it is used only during refueling and is not used during normal operation, so there is a problem that the utilization efficiency of the reactor building is low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and uses an equipment pit that is used only at the time of refueling as a cooling water pool for a containment heat removal facility or an emergency condenser during normal operation. Accordingly, an object of the present invention is to provide a nuclear power plant capable of eliminating a large cooling water pool, reducing the size of a reactor building, and reducing the amount of material.

[0015]

According to a first aspect of the present invention, a fuel pool and an equipment pit are provided outside a containment vessel for storing a reactor pressure vessel, and the fuel pool and the equipment pit communicate with each other. A heat exchanger for the PCV heat removal equipment is installed in the heat exchanger, the inlet side of the heat exchanger and the inside of the PCV are connected with the PCV steam supply pipe, and the outlet side of the heat exchanger. The reactor pressure vessel is connected to a containment vessel heat removal equipment condensate return pipe. Claim 2
The invention is characterized in that the heat exchanger for containment heat removal equipment installed in the fuel pool is removed and replaced in the equipment pit.

According to the first and second aspects of the present invention, the heat exchanger for the heat removal equipment for the containment vessel is arranged in one of the fuel pool and the equipment pit, and the fuel pool communicates with the equipment pit to form a large heat sink. Thereby, the cooling water pool can be deleted.

According to a third aspect of the present invention, the heat exchanger for containment heat removal equipment is configured to be movable and detachable on a floor on which the fuel pool and the equipment pool are installed. Features.

According to the third aspect of the present invention, the heat exchanger for the PCV heat removal equipment disposed in the fuel pool or in the equipment pit is detached at the time of refueling and is moved to the floor so that the equipment pit can be moved to the initial state. The head of the reactor pressure vessel and the reactor internals can be stored underwater as intended.

According to a fourth aspect of the present invention, a fuel pool and equipment are provided outside a containment vessel for storing a reactor pressure vessel, the fuel pool and equipment pits are communicated, and an emergency condenser is provided in the fuel pool. A heat exchanger for equipment is installed, and the inlet side and the outlet side of this heat exchanger are respectively connected to the reactor pressure vessel by a steam supply pipe for emergency condenser equipment and a condensate return pipe for emergency condenser equipment. It is characterized by being connected. The invention according to claim 5 is characterized in that the heat exchanger for emergency condenser equipment installed in the fuel pool is removed and replaced in the equipment pit.

According to the fourth and fifth aspects of the present invention, the heat exchanger of the emergency condenser is arranged in one of the fuel pool and the equipment pit, and the fuel pool communicates with the equipment pit to form a large heat sink. Thereby, the cooling water pool can be deleted.

According to a sixth aspect of the present invention, the heat exchanger for emergency condenser equipment is configured to be movable and detachable on a floor on which the fuel pool and the equipment pool are installed. It is characterized by.

According to the sixth aspect of the present invention, the heat exchanger of the emergency condenser disposed in the fuel pool or the equipment pit is removed at the time of refueling and is moved to the floor so that the equipment pit can be initially moved. The head of the reactor pressure vessel and the reactor internals can be stored underwater as intended.

According to a seventh aspect of the present invention, the fuel pool and the equipment pit are arranged adjacent to each other, and a gate is provided between the fuel pool and the pit instead of the communication pipe. A fuel pool and the equipment pit are communicated with each other. The invention according to claim 8 is characterized in that the fuel pool and the equipment pit are integrated without providing the communication pipe.

The invention according to claim 9 is characterized in that a fuel pool cooling system for transferring heat generated in the fuel pool to a final heat sink is connected to an emergency power supply. According to the invention of claims 7 and 8, the invention relates to a structure for communicating the fuel pool with the equipment pit. In claim 7, communication is provided by providing a communication pipe. In claim 8, the fuel pool and the equipment pit are arranged adjacent to each other. According to the ninth aspect, the fuel pool and the equipment pit are formed as a pool having an integral size, so that the fuel pool and the equipment pit can be connected to each other to simplify the respective structures.

The invention according to claim 10 is characterized in that a fuel pool replenishment water system for supplying water into the fuel pool is connected to an emergency power supply. According to the invention of claim 10, the water temperature in the fuel pool rises due to the heat transmitted by the heat exchanger at the beginning of the event, but in order to prevent the pool water from rising excessively in the long term, the fuel pool cooling system is Although it is provided, it is connected to the emergency power supply to maintain the cooling function even if the external power supply is lost.

According to the first and fourth aspects of the present invention, the fuel pool replenishing water system for supplying the pool water is connected to the emergency power source in case the fuel pool cooling system does not operate for some reason, and the pool water temperature is controlled. In the event that the water continues to rise and boil, new cooling water is supplied, and the function of the PCV heat removal equipment or emergency condenser can be maintained.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a nuclear power plant according to the present invention will be described with reference to FIG.
In FIG. 1, the same portions as those in FIGS. 9 and 10 are denoted by the same reference numerals, and the description of the overlapping portions will be omitted. This embodiment is shown in FIG.
As shown in (1), the heat exchanger 5 for the heat removal equipment of the containment vessel is arranged in the fuel pool 8 and the communication pipe 13 is provided between the fuel pool 8 and the equipment pit 9 so that the fuel pool 8 and the equipment pit 9 Communication.

When a coolant loss accident occurs due to a pipe break in the containment vessel 3, the reactor scrams, but steam generation due to decay heat continues. The generated steam is released into the containment vessel 3 through the break, is guided to the heat exchanger 5 for the heat removal equipment of the containment vessel by the steam supply pipe 6, and is connected to the equipment pit 9 and the communication pipe 13.
The condensed water is condensed by the heat removal in the fuel pool 8 communicated through the condensate, and is returned to the storage container 3 again by the condensate return pipe 7.

In the early stage of the accident, the water temperature in the fuel pool 8 rises due to the heat transmitted from the heat exchanger 5, but the operation of the fuel pool cooling system 10 is started within a sufficient time of several hours. The water temperature rise of 8 stops. Since the fuel pool 8 and the equipment pit 9 are configured to communicate with each other through the communication pipe 13, the heat capacity of the pool water is large.

The speed of this initial rise in water temperature is moderate as compared with the conventional heat removal equipment for containment vessels. In the initial stage, the heat exchanger 5 for the PCV heat removal equipment is installed above the reactor, and steam and condensate circulate by natural circulation due to the density difference without depending on external power to remove decay heat. Is performed.

The long-term heat removal is performed by starting the operation of the fuel pool cooling system 10, and the generated heat is transferred to the final heat sink outside the nuclear power plant. For this reason, the storage container can continue to remove heat for a long period of time.

In the event that the operation of the fuel pool cooling system 10 fails, the fuel pool replenishing water system 11 supplies water to the fuel pool 8 to secure the heat capacity of the pool water for a long period of time. Thus, the heat removal of the containment vessel can be continued.

The fuel pool cooling system 10 and the fuel pool make-up water system 11 are both connected to an emergency power supply. Therefore, the above function can be performed even when the external power supply is lost, and the cooling of the storage container can be maintained for a long time.

Next, an outline at the time of refueling in the first embodiment of the present invention will be described with reference to FIG. During refueling, the reactor pressure vessel head 4 is removed and this head 4 is moved to the equipment pit 9. At this stage, the containment vessel 3 and the reactor pressure vessel 1 are open. The containment heat removal equipment cannot supply steam to the steam supply pipe 6 and does not function.

During this period, in order to move the fuel in the reactor pressure vessel 1 to the fuel rack 12 in the fuel pool 8, the reactor pressure vessel head 4 and the reactor internals 2 are removed, and the equipment pit 9 It is moved to. In this case, the equipment pit 9 can be used effectively by removing the heat exchanger 5 for the containment heat removal equipment and moving it to the fuel pool floor 14.

Next, a second embodiment of the nuclear power plant according to the present invention will be described with reference to FIG. In FIG. 2, FIG.
The same parts as those described above are denoted by the same reference numerals and the description of the overlapping parts will be omitted.

The present embodiment differs from the first embodiment in that the heat exchanger 5 for the heat removal equipment for the containment vessel is arranged in the equipment pit 9. Other parts are the same as in the first embodiment. Connecting pipe between fuel pool 8 and equipment pit 9
The configuration for communication at 13 is the same as in the first embodiment.

The operation of the present embodiment is the same as that of the first embodiment, and a description thereof will be omitted. Although an explanatory diagram of the present embodiment at the time of refueling is not shown, it is apparent that the same operation and effect as those of the first embodiment are provided.

Next, a third embodiment of the nuclear power plant according to the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that the heat exchanger 15 for the emergency condenser equipment is arranged in the fuel pool 8 and the fuel pool 8 and the equipment pit 9 are communicated by the communication pipe 13. I have done it.

When the reactor pressure vessel 1 is isolated, the reactor scrams, but steam generation due to decay heat continues. The generated steam is supplied to a steam supply pipe provided in the reactor pressure vessel 1.
The heat is guided to the heat exchanger 15 for the emergency condenser equipment by 16 and condensed by the heat removal in the fuel pool 8 which communicates with the equipment pit 9 through the communication pipe 13 to become condensed water. It is returned into the reactor pressure vessel 1.

In the early stage of the accident, the water temperature in the fuel pool 8 rises due to the heat transmitted from the heat exchanger 15, but by starting the operation of the fuel pool cooling system 10 within a sufficient time of several hours, the fuel The rise in the water temperature of the pool 8 stops. Since the fuel pool 8 and the equipment pit 9 are configured to communicate with each other through the communication pipe 13, the heat capacity of the pool water is large, and the speed of the initial rise in the water temperature is gentler than that of the conventional emergency condenser. .

In the initial stage, the heat exchanger 15 for the emergency condenser equipment is installed above the reactor, and steam and condensate circulate by natural circulation due to the density difference without depending on external power. Decay heat is removed.

The long-term heat removal is performed by starting the operation of the fuel pool cooling system 10, and the generated heat thereafter is transferred to the final heat sink outside the nuclear power plant. For this reason, the storage container can continue to remove heat for a long period of time.

In the event that the operation of the fuel pool cooling system 10 fails, the fuel pool 8 is replenished with water by the fuel pool replenishing water system 11 to secure the heat capacity of the pool water for a long period of time. Thus, the heat removal of the reactor pressure vessel 1 can be continued.

The fuel pool cooling system 10 and the fuel pool makeup water system 11 are both connected to an emergency power supply. Therefore, the above function can be performed even when the external power supply is lost, and the cooling of the reactor pressure vessel 1 can be maintained for a long time.

Next, an outline at the time of refueling in the third embodiment of the present invention will be described with reference to FIG. At the time of refueling, the reactor internals 2 and the reactor pressure vessel head 4 are moved to the equipment pit 9 as shown in FIG. 6, and the containment vessel 3 and the reactor pressure vessel 1 are open. The emergency condenser cannot supply steam to the steam supply pipe 16 and does not function.

During this period, the fuel in the reactor pressure vessel 1 is moved to the fuel rack 12 in the fuel pool 8, and the reactor pressure vessel head 4 and the reactor internals 2 are moved into the equipment pit 9. By removing the heat exchanger 15 for emergency condenser equipment and moving it to the fuel pool floor 14,
The equipment pit 9 can be used effectively.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the first embodiment is that the heat exchanger 15 for the emergency condenser equipment is connected to the equipment pit 9.
It is configured to be placed inside. The configuration in which the fuel pool 8 and the equipment pit 9 are communicated with each other by the communication pipe 13 is the same as that of the third embodiment.

The operation and effect of the present embodiment are the same as those of the third embodiment, and their explanation will be omitted. Also,
Although an explanatory diagram of the present embodiment at the time of fuel exchange is not shown, it is apparent that the same operation and effect as those of the fourth embodiment are provided.

Next, a fifth embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first to fourth embodiments in that a fuel pool 8 and an equipment pit 9 are arranged adjacent to each other, and a gate is provided between the fuel pool 8 and the equipment pit 9.
18 is to communicate both. The operation and effects of the present embodiment are the same as those of the first to fourth embodiments, and furthermore, it is possible to reduce the size and the amount of the reactor building.

Next, a sixth embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first to fourth embodiments in that a large fuel pool 21 in which the fuel pool 8 and the equipment pit 9 are integrated is configured.

The operation and effects of this embodiment are the same as those of the first to fifth embodiments, and the gate 18
Therefore, it is possible to further reduce the size of the reactor building and reduce the quantity of the reactor building.

It is apparent that the nuclear power plant according to the present embodiment described above may be configured so as to simultaneously include the heat removal equipment for the containment vessel and the emergency condenser.

[0054]

According to the present invention, the equipment pit used only at the time of refueling can be used as the cooling water pool of the containment heat removal equipment or the emergency condenser equipment during normal operation. Since the large cooling water pool can be eliminated, the size and the amount of the reactor building can be reduced. Therefore, an economically excellent nuclear power plant can be obtained.

[Brief description of the drawings]

FIG. 1 is an elevational view schematically showing a first embodiment of a nuclear power plant according to the present invention in a partial longitudinal section.

FIG. 2 is an elevational view schematically showing a second embodiment of the nuclear power plant according to the present invention in a partial longitudinal section.

FIG. 3 is an elevational view schematically showing a state at the time of refueling according to the first or second embodiment of the present invention.

FIG. 4 is an elevational view schematically showing a third embodiment of the nuclear power plant according to the present invention in a partial longitudinal section.

FIG. 5 is an elevational view schematically showing a fourth embodiment of the nuclear power plant according to the present invention in a partial longitudinal section.

FIG. 6 is an elevational view schematically showing a state at the time of refueling of a third embodiment of the nuclear power plant according to the present invention.

FIG. 7 is a top view schematically showing a fifth embodiment of the nuclear power plant according to the present invention in a partial cross section.

FIG. 8 is a top view schematically showing a sixth embodiment of the nuclear power plant according to the present invention in a partial cross section.

FIG. 9 is an elevational view schematically showing a first example of a conventional nuclear power plant in a partial longitudinal section.

FIG. 10 is an elevational view schematically showing a second example of a conventional nuclear power plant in a partial longitudinal section.

[Explanation of symbols]

1 ... reactor pressure vessel, 2 ... reactor internals, 3 ... containment vessel,
4 ... Reactor pressure vessel head, 5 ... Container heat removal equipment heat exchanger, 6 ... Containment vessel heat removal equipment steam supply pipe, 7 ... Containment vessel heat removal equipment condensate return pipe, 8 ... Fuel pool, 9: Equipment pit, 10: Fuel pool cooling system, 11: Fuel pool makeup water system, 12: Fuel rack, 13: Communication pipe, 14: Fuel pool floor, 15: Heat exchanger for emergency condenser equipment, 16 … Steam supply pipe for emergency condenser equipment, 17… Condenser return pipe for emergency condenser equipment, 18… Gate, 19… Cooling water pool for PCV heat removal equipment, 20… Emergency condenser equipment Cooling water pool for 21 ... Large fuel pool.

Claims (10)

[Claims] 1. A heat exchanger for containment heat removal equipment, wherein a fuel pool and an equipment pit are provided outside a containment vessel for storing a reactor pressure vessel, and the fuel pool and the equipment pit communicate with each other. The heat exchanger inlet side and the inside of the containment vessel are connected by a steam supply pipe for containment vessel heat removal equipment, and the outlet side of the heat exchanger and the reactor pressure vessel are heat removed from the containment vessel. A nuclear power plant connected by a condensate return pipe for equipment. 2. The nuclear power plant according to claim 1, wherein the heat exchanger for containment heat removal equipment installed in the fuel pool is removed and replaced in the equipment pit. 3. The heat exchanger for containment vessel heat removal equipment is configured to be movable and detachable on a floor on which the fuel pool and the equipment pool are installed. 2. The nuclear power plant according to 1. 4. A heat exchanger for an emergency condenser equipment, wherein a fuel pool and equipment are installed outside a containment vessel for storing a reactor pressure vessel, and the fuel pool and equipment pit communicate with each other. And the inlet side and the outlet side of this heat exchanger are connected to the reactor pressure vessel by a steam supply pipe for emergency condenser equipment and a condensate return pipe for emergency condenser equipment, respectively. A nuclear power plant characterized by the following. 5. The nuclear power plant according to claim 4, wherein the heat exchanger for emergency condenser equipment installed in the fuel pool is removed and replaced in the equipment pit. 6. The heat exchanger for emergency condenser equipment is configured to be movable and detachable on a floor on which the fuel pool and the equipment pool are installed. Item 6. A nuclear power plant according to item 4. 7. The fuel pool and the equipment pit are arranged so as to be adjacent to each other, and a gate is provided between the fuel pool and the pit instead of the communication pipe. 7. The nuclear power plant according to claim 1, wherein the nuclear power plant is communicated with a pit. 8. The nuclear power plant according to claim 1, wherein the fuel pool and the equipment pit are integrated without providing the communication pipe. 9. The nuclear power plant according to claim 7, wherein a fuel pool cooling system for transferring heat generated in the fuel pool to a final heat sink is connected to an emergency power supply. 10. The nuclear power plant according to claim 7, wherein a fuel pool makeup water system for supplying water into the fuel pool is connected to an emergency power supply.