JPH07209471A - Pool water system of nuclear power plant - Google Patents

Abstract

(57) [Summary] [Purpose] The suppression pool water purification system can be provided effectively and fully by providing an independent suppression pool water purification system and ensuring the purification function while also providing a function in case of an accident. Providing a pool water system for a nuclear power plant. [Structure] The lower suppression pool water purification system has a filter desalination unit 20 and a filtration desalination unit 20 which are separate and independent from a fuel pool water cooling / purification system (described later). And valve 48,
47, 46, 42, 41, 75 are open and the valve 4
9, 45, 54, 43, 73 and 74 are in the closed state. Pool water in the lower suppression pool 5 is strainer 1
6 is led to the pump 9 through the valve 48, and the pipe 24
After being purified by the filter demineralizer 20 via a, a pipe 23d via a valve 42 of the pipe 32 and a valve 41 of the pipe 23c.
To return to the lower suppression pool 5 again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to pool water of a nuclear power plant, and more particularly to a pool water system of a nuclear power plant having a suppression pool water purification system for purifying the suppression pool water.

[0002]

2. Description of the Related Art Suppression pool water in a reactor containment vessel accumulates insoluble corrosion products and ionic corrosion products when stored for a long period of time. Therefore, it is necessary to purify the suppression pool water. Conventionally known technologies for purifying suppression pool water include, for example, the following. JP, 58-28698, A In this publicly known art, not only purification of fuel pool water but also purification of suppression pool water is carried out by leading suppression pool water to a purification device which purifies fuel pool water via a connecting piping. Is also possible. JP, 63-180893, A JP, 2-38897, A These publicly known art introduces suppression pool water to a purification device which purifies fuel pool water, without providing an independent pump, and is a structure and operation. Is intended to be simplified. In this known technique, the inner surface of the bottom of the suppression pool is V-shaped.
By forming it into a V-shape, the pool water containing the precipitate in the suppression pool is guided from the drain port at the bottom of the V-shape to the purification device via the connecting pipe, enabling automatic cleaning of the suppression pool. .

[0003]

However, the above-mentioned known techniques have the following problems. That is, in the known technology, an independent suppression pool water purification system is not provided, but a structure in which the fuel pool water purification system and the suppression pool water purification system are used together, and the fuel pool water purification system must be temporarily stopped. Unable to purify suppression pool water. That is, it is extremely difficult to purify the suppression pool water for a long time during normal operation or during regular inspection, and as a result, the purification function is insufficient. In the known technology, the suppression pool water and the fuel pool water are mixed and supplied to the fuel pool water purification system to collectively purify them. Therefore, unlike the above, the suppression can be achieved without stopping the fuel pool water purification system. It is a structure that can purify pool water. However, in reality, unlike the suppression pool water, the fuel pool water is required to have a high degree of water purity, and mixing the suppression pool water with the fuel pool water purification system in this way increases the burden on the purification device. It is extremely difficult to operate, and even if it is operated, the mixture ratio of the suppression pool water must be greatly reduced. Therefore, like the above-mentioned known technique, it is extremely difficult to purify the suppression pool water for a long time during the normal operation or the regular inspection, which is not preferable as the purifying function.

Further, in the known art, although an independent suppression pool water purification system is provided, no consideration is given to other functions provided in case of an accident. That is, the suppression pool water cannot be moved and used for other purposes such as fuel pool and water filling of reactor wells. Therefore, it was insufficient when viewed as the function of the suppression pool water purification system as a whole.

Further, in the known art, it is not possible to completely remove water from the suppression pool because there is no facility for moving or replacing a large amount of pool water in the suppression pool. Therefore, maintenance work such as inspection / inspection / repair of the suppression pool inner wall / pool water purification equipment cannot be fully performed in a perfect condition, and the function of the entire suppression pool water purification system may not be effectively and sufficiently exerted. It was happening. In the known art, while suppressing pool water and fuel pool water are mixed and supplied to a cleaning system of the fuel pool water for purification, about 40% of the suppression pool water is placed in the fuel pool and about 60% is temporarily installed in the equipment. It is a structure to move to the pool. However, as described above, when the suppression pool water is mixed with the fuel pool water purification system, the burden on the purification device of the fuel pool water purification system becomes extremely large. Was difficult to drain.

Further, in the known art, the suppression pool has a V-shaped cross-section, and is a lower take-out system in which precipitates are collected and taken out to the center with an inclination from both end wall surfaces toward the center downward. Therefore, the connecting pipe will be routed further downward from the drainage port provided on the bottom of the pool, and the height of the connecting pipe space will be needed separately. The effective pool capacity is reduced. Therefore, in order to prevent this as much as possible, the communication pipe had to be shortened, and the flow rate of the suppression pool water purification system was limited, so that the purification function could not be fully exhibited.

A first object of the present invention is to provide a pool water system for a nuclear power plant, which can effectively and sufficiently exert the function of the suppression pool water purification system. A second object of the present invention is to independently provide a suppression pool water purification system to ensure the purification function and also to provide a function provided in the event of an accident, so that the function of the suppression pool water purification system can be effectively and sufficiently exhibited. It is to provide a pool water system for nuclear power plants. A third object of the present invention is to provide a pool water system of a nuclear power plant that enables the suppression pool to be completely drained of water, thereby effectively and sufficiently exhibiting the function of the suppression pool water purification system.

A fourth object of the present invention is to enable the automatic washing of the suppression pool without reducing the effective capacity of the suppression pool to improve the water quality, thereby effectively and sufficiently exhibiting the function of the suppression pool water purification system. Is to provide a pool water system for nuclear power plants.

[0009]

In order to achieve the above first and second objects, according to the present invention, a fuel pool and a suppression pool provided outside a reactor pressure vessel,
In a pool water system of a nuclear power plant, which comprises at least one first purification means, takes in water from the fuel pool, purifies the pool water, and returns the pool water to the fuel pool. A second purifying means independent of the purifying means is provided to take in the water from the suppression pool, purify the pool water and return it to the suppression pool, and can operate independently and simultaneously with the operation of the fuel pool water purifying system. A pool water system for a nuclear power plant, comprising: a suppression pool water purifying system; and a transfer pipe that connects the suppression pool and the fuel pool and can supply the water of the suppression pool to the fuel pool. Will be provided.

In order to achieve the above first and third objects, according to the present invention, a fuel pool and a plurality of suppression pools provided outside the reactor pressure vessel, and at least one first purification means. And a fuel pool water purification system that takes in water from the fuel pool and purifies the pool water and returns the pool water to the fuel pool.
A suppression pool and a second suppression pool, and the first suppression pool and the second suppression pool are connected to each other so that the water of the first suppression pool can be supplied to the second suppression pool. A first transfer pipe, and a second transfer pipe that connects the second suppression pool and the fuel pool and is capable of supplying the water of the second suppression pool to the fuel pool. A nuclear power plant pool water system will be provided.

Preferably, in the pool water system of the nuclear power plant, the first transfer pipe takes in the pool water of the first suppression pool, cools the pool water, and returns it to the first suppression pool. A cooling means common to the residual heat removal system of the furnace is provided, and the cooling means transfers the pool water taken from the first suppression pool to the second suppression pool while cooling the pool water. A nuclear power plant pool water system will be provided.

Further, in order to achieve the above first to third objects, according to the present invention, a fuel pool and a plurality of suppression pools provided outside the reactor pressure vessel, and at least one first purification means. And a fuel pool water purification system that takes in water from the fuel pool and purifies the pool water and returns the pool water to the fuel pool.
A suppression pool and a second suppression pool, and the first suppression pool and the second suppression pool are connected to each other so that the water of the first suppression pool can be supplied to the second suppression pool. A first transfer pipe, a second transfer pipe that connects the second suppression pool and the fuel pool, and is capable of supplying the water of the second suppression pool to the fuel pool, and the first purification Second purification means independent of the means, and takes in the water of the first suppression pool, purifies the pool water and returns it to the first suppression pool, and separates the fuel pool water purification system simultaneously with the operation. Pool water for a nuclear power plant, which has a suppression pool water purification system Integration is provided.

To achieve the above first and fourth objects, according to the present invention, pool water of a nuclear power plant equipped with a fuel pool and at least one suppression pool provided outside the reactor pressure vessel In the system, the first suppression pool having a substantially circular horizontal cross-sectional shape among the at least one suppression pool includes a bottom surface having a structure in which a plurality of substantially fan-shaped bottom surface segments are combined, and a substantially circular shape. A plurality of inlets provided near the central portion for injecting pool water, and a plurality of outlets provided near the substantially circular circumferential portion for draining the pool water, Each of the bottom surface segments has both end faces extending radially from the central portion of the substantially circular shape, and one of the both end faces descends radially outward from the central portion. And the other is a second inclined end surface having a lower height in the vertical direction than the first inclined end surface and having a downward slope from the central portion toward the radially outer side, The inlet is provided near the uppermost portion of the first inclined end surface, the drain outlet is provided near the lowermost portion of the second inclined end surface, and the pool water is purified to purify the pool water. A pool water system of a nuclear power plant is further provided in which a drain pipe leading to the means is connected to the drain port in a substantially horizontal direction.

[0014] Preferably, in the pool water system of the nuclear power plant, the at least one suppression pool includes a second suppression pool in addition to the first suppression pool.
The suppression pool is provided, and the first
And a second suppression pool are connected to each other, and cleaning pipes for guiding pool water of the second suppression pool to the plurality of inlets of the first suppression pool are provided. Local pool water system is provided.

[0015]

In the present invention constructed as above, the first
Purifying the fuel pool water by the fuel pool water purifying system having the purifying means and simultaneously operating the suppression pool water purifying system having the independent second purifying means separately and independently. The suppression pool water can be purified without stopping the system and without mixing the suppression pool water and the fuel pool water, so that the suppression pool water can be purified for a long time during the normal operation or the regular inspection. In addition, since the transfer pipe that connects the suppression pool and the fuel pool is provided, it is possible to transfer the water of the fuel pool to the reactor well to perform water filling, and to cope with the occurrence of loss of coolant, etc. be able to. At this time, the water in the suppression pool can be transferred to the fuel pool to fill it with water.

Further, in the present invention, a plurality of suppression pools are provided, and the first transfer pipe connecting the first suppression pool and the second suppression pool, and the second suppression pool and the fuel pool are connected. By having the second transfer pipe, the second
Transfer the water from the suppression pool to the fuel pool and then all the water from the first suppression pool to the second
The first suppression pool can be completely drained from the first suppression pool. Further, as a configuration example at this time, a cooling means common to the residual heat removal system of the reactor is provided in the first transfer pipe, and the pool water taken from the first suppression pool is cooled and transferred to the second suppression pool. There is a configuration.

Further, in the present invention, the pool water is injected from the injection port near the uppermost portion of the first inclined end surface which is inclined radially outward from the central portion, and the second pool having a height lower than that of the first inclined end surface is provided. By draining from the discharge port near the lowermost part of the inclined end face, pool water flows in the circumferential direction from the first inclined end face to the second inclined end face in each bottom surface segment and to the outlet near the second inclined end face. It flows in a radial direction, and precipitates on the entire bottom surface are removed evenly and automatic cleaning is possible. At this time, by connecting the drainage pipe that guides the pool water to the purification means in a substantially horizontal direction with respect to the drainage port, the connection pipe is laid further downward from the drainage port as in the conventional case, and the height is separately increased. Never needed. That is, the effective capacity of the suppression pool does not decrease. Further, as a configuration example at this time, there is a configuration in which a second suppression pool is provided in addition to the first suppression pool, and the second suppression pool is guided to a plurality of injection ports of the first suppression pool by a cleaning pipe.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The overall structure of the pool water system of the nuclear power plant of this embodiment is shown in FIG. Hereinafter, the valves in the open state are shown in white and the valves in the closed state are shown in black in the figure. Note that, in FIG. 2, for convenience, all valves are shown in a closed state. In FIG. 2, the pool water system of this embodiment includes a fuel pool 3 provided outside the reactor pressure vessel 1 in contact with the reactor well 2, an upper suppression pool 6 provided outside the reactor pressure vessel 1, and Lower suppression pool 5
And a clearance surge tank 7 close to the fuel pool 3,
It has a temporary equipment pool 4. Further, the pool water system of the present embodiment includes a lower suppression pool water purification system for purifying the pool water of the lower suppression pool 5, a fuel pool water cooling / purification system for cooling / purification of the pool water of the fuel pool 3, and an upper suppression. An upper suppression pool water transfer system for transferring pool water from pool 6 to fuel pool 3,
An upper suppression pool water purification system that purifies pool water of the upper suppression pool 6, a lower suppression pool water transfer system that transfers pool water of the lower suppression pool 5 to the upper suppression pool 6 and drains water of the lower suppression pool 5. Reactor residual heat removal system for cooling pool water in the lower suppression pool 5, suppression pool cleaning system for automatic cleaning of the lower suppression pool 5, and many other piping systems (valves,
However, since the same piping system may be used for a plurality of purposes in the present embodiment, these piping systems will be described below in order according to the function of each piping system.

First, the lower suppression pool water purification system in the pool water system of this embodiment will be described with reference to FIGS. Figure 1 shows the lower suppression pool water purification system. In FIG. 1, the lower suppression pool water purification system is a filter demineralizer 1 of a fuel pool water cooling / purification system (described later).
8 and 19 and a filter demineralizer 20 independent of each other. The valves 48, 47, 46, 42, 41, 75 provided on the pipes 24a, 32, 23c, 23d are in the open state, and are provided on the pipes 30, 31, 24a, 32, 25h, 23e. The valves 49, 45, 54, 43, 73, 74 are closed. Other valves may be either open or closed, but for the sake of clarity, they are all shown closed. The pool water in the lower suppression pool 5 is guided from the strainer 16 to the pump 9 via the valve 48 and further purified by the filter desalting device 20 via the pipe 24a, and then the valve 42 of the pipe 32 and the valve of the pipe 23c. It returns to the lower suppression pool 5 again from the pipe 23d via 41.
The purification of the lower suppression pool water is performed in conjunction with the cleaning (described later) of the lower suppression pool 5 by the lower suppression pool cleaning system.

By the way, the lower suppression pool water purification system of the present embodiment is characterized in that it has a completely independent structure from the fuel pool water cooling / purification system and can operate simultaneously therewith. The fuel pool water cooling / purification system will be described below. In FIG. 1, the fuel pool water cooling / purification system has at least one (two in this embodiment) filter demineralizers 18, 19. And piping 25f, 25a
Valves 63, 62, 64, 65, 56, 71, 66, 6 provided on ₁ , 25a ₂ , 25b, 25c ₁ , 25c ₂ , 25d ₁ respectively
7,68,69,72,57 are open. And piping 2
The valves 70, 44, 43, 73, 40, 58, 55 provided on 3b, 31, 32, 25h, 25i, 26, 25g are closed. Other valves may be either open or closed, but for the sake of clarity, they are all shown closed. The water in the fuel pool 3 in the normal purification operation is
From the reactor well 2 through the pipe 25f, and further through the pipe 25
After being guided to the pipe 25b through the pump 11 of a ₁ and the pump 12 of the pipe 25a ₂ , separated into the pipes 25c ₁ and 25c ₂ and purified by the filter desalting devices 18 and 19 provided respectively , And is merged again, cooled by the heat exchanger 21 provided in the pipe 25d ₁ , and returned to the fuel pool 3 from the pipe 25d ₂ . At this time, the water from the space surge tank 7 close to the fuel pool 3 also joins the pipes 25a ₁ and a ₂ . In the above-described lower suppression pool water purification system of the pool water system of the present embodiment, the pool water of the fuel pool 3 is purified by the fuel pool water purification system equipped with the filter demineralizers 18 and 19, and at the same time, separate and independent filtration dewatering is performed. By separately and independently operating the suppression pool water purification system including the salt container 20, the pool water of the lower suppression pool 5 and the pool water of the fuel pool 3 are mixed without stopping the fuel pool water purification system. It is possible to purify the pool water of the lower suppression pool 5 without using it, and thus it is possible to purify the pool water of the lower suppression pool 5 for a long time even during normal operation or regular inspection.

In the above, the filter desalting machine 18,
19 was used in the fuel pool water purification / cooling system, of which the filter demineralizer 19 provided in the pipe 25c ₂ is a standby machine, and the filter demineralizer 18 provided in the pipe 25c ₁ is the main demineralizer. Function as a container. Therefore, if the fuel pool water purification system can be temporarily stopped, there is also the following configuration in which the filtration desalination device 19 is used in the suppression pool water purification system. This is shown in FIG. In FIG. 3, the pipe 23
The valves 81, 70, 68, 43, 41, 75 provided in a, 23b, 25c ₂ , 32, 23c, 23d are in the open state, and the pipes 30, 23a, 25b, 25c ₁ , 25c ₂ , 3
Valves 49,8 provided on 1,32,25h, 23e respectively
4,71,66,67,69,44,45,42,73,74 are in the closed state. Other valves may be either open or closed, but for the sake of clarity, they are all shown closed. The water in the lower suppression pool 5 is introduced from the strainer 15 to the pump 8 via the valve 81, further purified by the filter desalting device 19 via the pipes 23a, 23b and 25c _2, and then via the valves 43 and 41. It returns to the lower suppression pool 5 again from the pipe 23d.

Next, the lower suppression pool water transfer system and the upper suppression pool water transfer system in the pool water system of this embodiment will be described with reference to FIGS. In draining the lower suppression pool, first, the pool water of the upper suppression pool 6 is transferred.
This procedure is performed by the upper suppression pool water transfer system. The upper suppression pool water transfer system is shown in FIG. In FIG. 4, the upper suppression pool water transfer system has pipes 33, 25a ₂ , 25g, 25d ₂ that connect the upper suppression pool 6 and the fuel pool 3. The valves 50, 64, 55 provided on the pipes 33, 25a ₂ and 25g are in the open state, and the pipe 25a
_The valves 56, 62, 57 respectively provided at ₂ , 25d ₁ are closed. The valves other than these may be either open or closed, but for the sake of clarity, they are all shown closed. The pool water in the upper suppression pool 6 is
It is guided from the strainer 13 to the pump 12 through the pipe 33, and further to the fuel pool 3 through the pipes 25a ₂ , 25g and 25d ₂ . As a result, the water in the fuel pool 3 can be transferred to the reactor well 2 and filled with water, and the occurrence of a loss of coolant or the like can be dealt with. Then, after this, the water in the lower suppression pool 5 is transferred to the fuel pool 3 by the lower suppression pool transfer system to perform water filling. While the pool water in the upper suppression pool 6 is being moved, the water purification operation in the lower suppression pool 5 is continued (see FIG. 4).

After the above procedure is completed and the water in the upper suppression pool 6 is completely transferred to the fuel pool 3, then
The lower suppression pool water transfer system purifies the water in the lower suppression pool 5 and transfers it to the upper suppression pool 6 to drain water from the lower suppression pool 5.

A lower suppression pool water transfer system is shown in FIG.
Shown in. In FIG. 5, the lower suppression pool water transfer system connects the lower suppression pool 5 and the upper suppression pool 6 and can supply the pool water of the lower suppression pool 5 to the upper suppression pool 6 by the pipes 24a to 24c and the pipes 29a to 29c. , 36b, 36c. And 48, 47, 46, 54, 59, 60, 61, 7 provided on the pipes 24a, 29a, 36b, 36c, respectively.
9,80,77,39 are in the open state, and the piping 30,31,3
2,26,25b, 25c ₁ , 25h, 27,28,36a, 2
49, 45, 42, 58, 71 provided on 5i,
66, 73, 37, 38, 83, 40 are closed. The valves other than those mentioned above may be either open or closed, but for the sake of clarity, they are all shown closed.

The water in the lower suppression pool 5 is introduced from the strainer 16 to the pump 9 via the valve 48, further purified by the filter desalting device 20 via the pipe 24a, and then the upper portion via the pipes 24b and 24c. It is supplied into the suppression pool 6. At the same time, the water in the lower suppression pool 5 flows from the strainer 17 to the pipe 29a.
Is also led to the pump 10 via the pipe 29b, cooled by the heat exchanger 22 via the pipe 29b, and then led from the valve 77 to the pipe 24b via the pipes 36b and 36c to join the previous flow.

By the way, of the above, the pipes 29a to 29c are common to the residual heat removal system of the nuclear reactor. That is, the lower suppression pool water transfer system of the present embodiment is characterized in that it uses a part of the residual heat removal system of the reactor. This reactor residual heat removal system will be described below with reference to FIG.
In FIG. 6, the reactor residual heat removal system includes pipes 29a to 29c.
And a heat exchanger 22. Then, the valves 59, 60, 61, 79, 80 provided on the pipes 29a to 29c and the valve 76 provided on the pipe 34 are opened, and the pipes 28, 36a, 3
The valves 38, 83, 77 respectively provided on 6b are closed. Other valves may be either open or closed, but for the sake of clarity, they are all shown closed. The water in the lower suppression pool 6 is taken in from the strainer 17 by the pump 10, guided to the pipe 29 a, cooled in the heat exchanger 22, and then the pipe 29.
Return to the lower suppression pool 5 via c, 34 and valve 76. That is, part of the lower suppression pool water transfer system of the pool water system of the present embodiment uses the heat exchanger 22 of the residual reactor heat removal system to cool the pool water taken from the lower suppression pool 5 while the upper part is cooled. It is transferred to the suppression pool 6.

In the upper suppression pool water transfer system and the lower suppression pool water transfer system of the present embodiment described above, the pipes 24a to 24c and the pipe 29a connecting the lower suppression pool 5 and the upper suppression pool 6 are connected.
To c, 36b, 36c, and pipes 33, 25a ₂ , 25g, 2 for connecting the upper suppression pool 6 and the fuel pool 3
Since 5d ₂ is provided, the pool water of the upper suppression pool 6 is transferred to the fuel pool 3 and then all the pool water of the lower suppression pool 5 is transferred to the upper suppression pool 6 so that the lower suppression pool 5 is completely removed. Drainage can be performed.

The water in the upper suppression pool 6 is drained by the pipes 33,
It can be easily carried out by transferring to the fuel pool 3 with 25a ₂ , 25g and 25d ₂ or transferring to the lower suppression pool 5 through the pipe 28 of the lower suppression pool cleaning system. Further, in the above embodiment, when the pool water of the lower suppression pool 5 is transferred by the lower suppression pool water transfer system as described above, the residual reactor heat removal system cannot be used. However, there are generally three reactor residual heat removal systems including those provided in the pool water system, so the reactor residual heat removal system in the pool water system of this embodiment is used among these three systems. Even if you can't, you can say that there is no safety problem. Furthermore, the drainage of the lower suppression pool 5 is performed both through the route through the filter desalting device 20 (via the pipe 24a) and through the heat exchanger 22 (pipes 29a to c, 36b, 36c). Although the case of using one of them is described, the case of using only one of them may be used, and in this case, the same effect is obtained. When only the former route is used, the reactor residual heat removal system can be continuously used as it is, and the above-mentioned problem does not occur.

Next, the lower suppression pool cleaning system in the pool water system of this embodiment will be described with reference to FIGS. The cleaning of the lower suppression pool 5 is carried out when the water removal from the lower suppression pool 5 by the upper suppression pool water transfer system and the lower suppression pool water transfer system is completed 100%. The lower suppression pool wash system is shown in FIG. In FIG. 7, the lower suppression pool cleaning system includes a lower suppression pool 5 and an upper suppression pool 6.
And the pipes 27 and 28 which connect to the lower suppression pool 5 and connect the pool water of the upper suppression pool 6 to the lower suppression pool 5. And the valves 38 and 51 provided in the pipe 28 and the pipe 2
7 is open and the valve 37 is open, and the pipe 29
The valves 60 and 61 provided on a and 29b are in the closed state. The other valves may be either open or closed, but for the sake of clarity, they are all shown closed.

The details of the lower suppression pool 5 are shown in FIG.
~ Shown in FIG. 8 is a plan view of the bottom surface of the lower suppression pool 5, FIG. 9 is a sectional view taken along line AA of FIG. 8, and FIG. 10 is a sectional view taken along line BB of FIG. 8 to 10
In, the lower suppression pool 5 has a substantially circular horizontal cross-sectional shape, and has a bottom surface 90 having a structure in which a plurality of fan-shaped (in this embodiment, 12) bottom surface segments 90A to L are combined. , A plurality of (six in this embodiment) inlets 91a to f provided near the central portion of the substantially circular shape and for injecting the pool water, and the pool water provided near the circumferential portion of the substantially circular shape to drain the pool water. It has a plurality of strainers (six in this embodiment) 16a to 16f. Each of the bottom surface segments 90A to 90L has an end surface 52 and an end surface 53 that extend in the radial direction from the central portion of the substantially circular shape and are inclined downward from the central portion toward the radial outer side on both sides. The end surface 53 has a lower height in the vertical direction than the end surface 52.
Strainer 1 near the lowermost part (that is, the end on the circumferential side) of
6a to 6f are provided, and inlets 91a to 91f connected to the pipe 27 are provided near the uppermost part of the end face 52. That is, the bottom surface 90 as a whole has a shape in which the high end surface 52 and the low end surface 53 are arranged so as to alternately form peaks and valleys in the circumferential direction (see FIG. 8). A pipe 24d is connected to the strainers 16a to 16f in a substantially horizontal direction (see FIG. 9), and the pool water containing the precipitate sucked by the strainers 16a to 16f is fed to the filter demineralizer 20 by the pipes 24d and 24a. Guided and purified.

In addition to the above, in the lower suppression pool 5, a strainer 15 (see FIG. 3) of the lower suppression pool water purification system when the fuel pool water cooling / purification system is stopped, and a pipe 23d of the lower suppression pool water purification system ( 1 and 3), and a strainer 17 for the residual heat removal system of the reactor and the water transfer system for the lower suppression pool.
(See FIGS. 5 and 6) and piping 3 of the residual heat removal system of the reactor.
4 (see FIG. 6) are provided.

In the above structure, the water in the upper suppression pool 6 is guided from the strainer 14 to the pipe 28 via the valve 51 and further to the pipe 27 by the pump 10 to near the bottom surface 90 of the suppression pool 5 via the valve 37. It is supplied to the provided injection ports 91a to 91f.

In the above-described lower suppression pool cleaning system, pool water is injected through the inlets 91a-f in the vicinity of the uppermost end face 52 that is inclined radially outward from the center, and the end face that is lower than the end face 52 in height. By draining from the strainers 16a to f in the vicinity of the lowermost 53, pool water flows circumferentially from the end face 52 to the end face 53 in each bottom surface segment 90A to L, and in the radial direction to the strainers 16a to f near the end face 53. Then, the precipitates (impurities, dusts, etc.) on the entire bottom surface 90 can be removed evenly for automatic cleaning. And at this time, the pool water is filtered and desalination unit 2
By connecting the pipe 24d that leads to 0 to the strainers 16a to 16f in a substantially horizontal direction, there is no need to separately draw the connecting pipe further downward from the drain port and increase the height as in the conventional case. . That is, the effective capacity of the suppression pool does not decrease. Here, when the lower suppression pool 5 is cleaned using the lower suppression pool cleaning system, the residual reactor heat removal system in the pool water system of the present embodiment cannot be used (see FIG. 6). However, there are generally three reactor residual heat removal systems, including those provided for pool water systems,
It can be said that even if the reactor residual heat removal system in the pool water system of the present embodiment cannot be used among these three systems, there is no safety problem.

As described above, according to the pool water system of the present embodiment, since the pool water of the fuel pool 3 is purified by the fuel pool water purification system, at the same time the suppression pool water purification system is operated independently. The pool water in the lower suppression pool 5 can be purified for a long period of time even during normal operation or during regular inspections. Therefore, the water quality of the lower suppression pool 5 can always be maintained in good condition, so that even in the event of a sudden accident, the water of which the water quality is ensured can be supplied to the reactor without polluting the reactor water. Further, since the transfer pipe connecting the upper suppression pool 6 and the fuel pool 3 is provided, the pool water of the fuel pool 3 is transferred to the reactor well 2 and water filling is performed to prevent occurrence of a coolant loss accident or the like. can do. Further, at this time, since the transfer to the fuel pool 3 is carried out directly without passing through the filter desalting apparatus as in the conventional case, the transfer of the pool water can be carried out promptly. That is, since the time until startup can be shortened, the operating rate can be improved. In addition, the lower suppression pool 5 and the upper suppression pool 6 of the lower suppression pool water transfer system.
Pipes 24a to c and pipes 29a to c, 36 for connecting with
b, 36c and the pipes 33, 25a ₂ , 25g, 25d ₂ connecting the upper suppression pool 6 of the upper suppression pool water transfer system and the fuel pool 3, the pool water of the upper suppression pool 6 is supplied to the fuel pool 3 After that, all the pool water in the lower suppression pool 5 can be transferred to the upper suppression pool 6 to completely drain the lower suppression pool 5. Also, draining water from the upper suppression pool 6
It can be easily carried out by transferring to the fuel pool 3 through the pipes 33, 25a ₂ , 25g and 25d ₂ or transferring to the lower suppression pool 5 through the pipe 28. Therefore, maintenance work such as inspection / inspection of the inner wall of the suppression pool and purification equipment can be sufficiently performed, and the reliability of the suppression pool can be secured. Furthermore, since pool water is injected by the lower suppression pool cleaning system from the inlets 91a-f near the top of the end face 52 and drained from the strainers 16a-f near the bottom of the end face 53, the pool water at each bottom surface segment 90A-L. Flows circumferentially from the end face 52 to the end face 53 and radially to the strainers 16a to 16f in the vicinity of the end face 53, so that the precipitates on the entire bottom surface 90 can be uniformly removed and automatically cleaned. Therefore, it is effective in improving the quality of the suppression pool water. Then, at this time, a pipe 24 for guiding the pool water to the filter desalination device 20.
Since d is connected to the strainers 16a to 16f in a substantially horizontal direction, it is not necessary to separately draw the connecting pipe downward from the drainage port and increase the height as in the conventional case.
That is, the effective capacity of the suppression pool does not decrease. Therefore, the function of the suppression pool water purification system can be effectively and sufficiently exhibited.

In the above embodiment, two suppression pools are provided, one upper and one lower, but the present invention is not limited to this. For the lower suppression pool cleaning system and the lower suppression pool water purification system, only one suppression pool is provided. When provided, it can be applied to the suppression pool, and the same effect can be obtained in this case as well.

[0036]

According to the present invention, since the fuel pool water is purified by the fuel pool water purifying system and the suppression pool water purifying system is independently operated at the same time, the suppression pool water is purified during the normal operation and the periodic inspection. Can be done for a long time. Therefore, the water quality of the suppression pool can always be maintained in good condition, so even in the event of a sudden accident,
It is possible to supply water of which the water quality is secured to the reactor without polluting the reactor water. Further, since the transfer pipe that connects the suppression pool and the fuel pool is provided, it is possible to transfer the water of the fuel pool to the reactor well and fill it with water to cope with an accident such as a loss of coolant. Further, at this time, as in the conventional case, the water is directly transferred to the fuel pool without passing through the filter desalting device, so that the pool water can be transferred quickly, the time until the start-up can be shortened, and the operation rate is improved. That is, the function of the suppression pool water purification system can be effectively and sufficiently exhibited.

Further, according to the present invention, a first transfer pipe connecting the first suppression pool and the second suppression pool, and a second transfer pipe connecting the second suppression pool and the fuel pool. Second because it has
Transfer the water from the suppression pool to the fuel pool and then all the water from the first suppression pool to the second
The first suppression pool can be completely drained from the first suppression pool. The second
The suppression pool can be drained easily by transferring it to the fuel pool through the second transfer pipe or transferring it to the first suppression pool through the cleaning pipe. Therefore, maintenance work such as inspection and inspection of the inner wall of the suppression pool and purification equipment can be fully performed in a perfect condition, and the reliability of the suppression pool can be secured, so that the function of the suppression pool water purification system can be effectively and fully demonstrated. it can. Further, according to the present invention, the pool water is injected from the inlet near the uppermost portion of the first inclined end surface and drained from the outlet near the lowermost portion of the second inclined end surface. It flows in the circumferential direction from the slanted end face to the second slanted end face and radially in the vicinity of the second slanted end face to the discharge port, so that the precipitate on the entire bottom surface can be uniformly removed and automatically washed. Therefore, it is effective in improving the quality of the suppression pool water. At this time, because the drainage pipe that guides the pool water to the purification means was connected to the drainage port in a substantially horizontal direction, it is necessary to draw the connection pipe further downward from the drainage port and increase the height separately as in the past. Never becomes. That is, the effective capacity of the suppression pool does not decrease. Therefore, the function of the suppression pool water purification system can be effectively and sufficiently exhibited.

[Brief description of drawings]

FIG. 1 is a diagram showing a lower suppression pool water purification system according to an embodiment of the present invention.

FIG. 2 is an overall structural diagram of a pool water system.

FIG. 3 is a diagram showing another lower suppression pool water purification system.

FIG. 4 shows an upper suppression pool water transfer system.

FIG. 5 is a diagram showing a lower suppression pool water transfer system.

FIG. 6 is a diagram showing a nuclear reactor residual heat removal system.

FIG. 7 shows a lower suppression pool wash system.

FIG. 8 is a plan view of the bottom surface of the lower suppression pool.

FIG. 9 is a partial cross-sectional view of the bottom surface of the lower suppression pool.

FIG. 10 is a partial cross-sectional view of the bottom surface of the lower suppression pool.

[Explanation of symbols]

1 Reactor Pressure Vessel 2 Reactor Well 3 Fuel Pool 5 Lower Suppression Pool (1st Suppression Pool) 6 Upper Suppression Pool (2nd Suppression Pool) 16a-f Strainer (Drainage Port) 18 Filtration Demineralizer (1st) Purification means) 19 Filtration demineralizer (first purification means) 20 Filtration demineralizer (second purification means) 22 Heat exchanger (cooling means) 24a to c piping (first transfer piping) 24d piping ( Drain pipe 25a ₂ pipe (transfer pipe / second transfer pipe) 25d ₂ pipe (transfer pipe / second transfer pipe) 25g pipe (transfer pipe / second transfer pipe) 27 pipe (cleaning pipe) 28 pipe ( Cleaning pipes) 29a to c pipes (first transfer pipes) 33 pipes (transfer pipes / second transfer pipes) 36b, c pipes (first transfer pipes) 52 end faces (first inclined end faces) 5 End surface (second inclined end face) 90 bottom 90A~L bottom segment 91a~f inlet

Claims (6)

[Claims] 1. A fuel pool and a suppression pool provided outside the reactor pressure vessel, and at least one first
And a fuel pool water purifying system for purifying the pool water and returning the pool water to the fuel pool, the pool water system of a nuclear power plant being independent of the first purifying unit. Suppression pool water that is equipped with the second purification means described above, takes in the water from the suppression pool, purifies the pool water and returns it to the suppression pool, and is capable of operating independently and simultaneously with the operation of the fuel pool water purification system. A pool water system of a nuclear power plant, comprising: a purification system; and a transfer pipe that connects the suppression pool and the fuel pool and that can supply the water of the suppression pool to the fuel pool. 2. A fuel pool provided outside the reactor pressure vessel, a plurality of suppression pools, and at least one first purification means, which takes in water from the fuel pool and purifies the pool water to obtain the fuel pool. In a pool water system of a nuclear power plant having a fuel pool water purification system that returns to the above, the plurality of suppression pools have a first suppression pool and a second suppression pool, and the first suppression pool and A first transfer pipe, which is connected to a second suppression pool and is capable of supplying water from the first suppression pool to the second suppression pool, and the second suppression pool and the fuel pool are connected to each other. A second transfer pipe capable of supplying the water of the second suppression pool to the fuel pool is provided. Pool water system of the nuclear power plant according to claim. 3. The pool water system of a nuclear power plant according to claim 2, wherein the first transfer pipe takes in pool water of the first suppression pool and cools the pool water to cool the first suppression pool. A cooling means common to the residual heat removal system for returning to the reactor is provided, and the cooling means transfers the pool water taken from the first suppression pool to the second suppression pool while cooling the pool water. A pool water system of a nuclear power plant, which is characterized in that 4. A fuel pool provided outside the reactor pressure vessel, a plurality of suppression pools, and at least one first purification means, which takes in water from the fuel pool and purifies the pool water to obtain the fuel pool. In a pool water system of a nuclear power plant having a fuel pool water purification system that returns to the above, the plurality of suppression pools have a first suppression pool and a second suppression pool, and the first suppression pool and A first transfer pipe, which is connected to a second suppression pool and is capable of supplying water from the first suppression pool to the second suppression pool, and the second suppression pool and the fuel pool are connected to each other. A second transfer pipe capable of supplying water from a second suppression pool to the fuel pool; A second purification means independent of the purification means is provided, and the water of the first suppression pool is taken in to purify the pool water and return it to the first suppression pool, and at the same time as the operation of the fuel pool water purification system. A pool water system for a nuclear power plant, which has a suppression pool water purification system that can operate independently. 5. A pool water system of a nuclear power plant, comprising a fuel pool provided outside a reactor pressure vessel and at least one suppression pool, wherein the at least one suppression pool has a substantially circular horizontal cross-sectional shape. The first suppression pool has a bottom surface having a structure in which a plurality of substantially fan-shaped bottom surface segments are combined, a plurality of inlets provided near the central portion of the substantially circular shape for injecting pool water, and And a plurality of drainage ports provided near the circumferential portion of the substantially circular shape for draining the pool water, and each of the plurality of bottom surface segments has both end surfaces extending in the radial direction from the central portion of the substantially circular shape. And one of the both end faces is a first inclined end face having a downward slope from the central portion toward the outside in the radial direction, and the other is the first inclined face. A second inclined end surface having a lower height in the vertical direction than the surface and a downward slope from the central portion toward the outer side in the radial direction, and the injection port is provided in the vicinity of the uppermost part of the first inclined end surface, The drainage port is provided near the lowermost part of the second inclined end face, and a drainage pipe for guiding the pool water to a purification means for purifying the pool water is connected to the drainage port in a substantially horizontal direction. A pool water system of a nuclear power plant characterized by being provided. 6. The pool water system of a nuclear power plant according to claim 5, wherein the at least one suppression pool is a second suppression pool in addition to the first suppression pool.
The suppression pool is provided, and the first
And a second suppression pool are connected to each other, and cleaning pipes for guiding pool water of the second suppression pool to the plurality of inlets of the first suppression pool are provided. Pool water system.