JP5696082B2 - Spilled fuel pool overflow control device and manufacturing method thereof - Google Patents

Description

  The present invention relates to an overflow control device for a spent fuel pool of a nuclear power plant and a method for manufacturing the same.

  Nuclear power plants have a spent fuel pool that stores fuel assemblies burned in the reactor in spent fuel racks and stores them while cooling them with a large amount of water. The section is located on the operation floor where the fuel changer and the like are installed.

  By the way, when a low-frequency external force such as an earthquake is applied to a container holding a liquid such as a pool, a swing called sloshing occurs on the liquid level in the container. When sloshing occurs in the spent fuel pool during an earthquake, the pool liquid level exceeds the pool side wall, pool water containing radioactive material overflows the operation floor, and the pool water spreads over a wide area, and spent fuel Pool water level may drop.

  Therefore, it is known that the conventional reactor building is equipped with an overflow control device in order to prevent overflow of pool water due to sloshing and dissipation of the pool water to the operation floor and improve the reliability of the nuclear power plant. (Patent Document 1).

  This overflow control device has an embankment around the spent fuel pool, and a handrail with a plate at the top, and a drainage groove to the spent fuel pool on the operation floor. And the pool water overflowing over the handrail with a plate is temporarily stored on the operation floor in the embankment or the handrail with a plate, and the overflowing pool water is recovered to the spent fuel pool through the drainage ditch. It has become.

JP 2007-163204 A

  Due to the impact of a major earthquake that has occurred in recent years, attention has been paid to measures against flooding around the spent fuel pool in nuclear power plants. The conventional overflow control device described above is configured to return the overflow to the fuel pool by providing drainage grooves on the floor surface and under the floor of the operation floor. Such a flood control device is planned in advance from the beginning of construction. There is a problem that a large-scale remodeling work is required when it is required to be installed and applied to an existing power plant.

  Embodiments according to the present invention have been made to solve the above-mentioned problems, and are simple and reliable overflow that prevents the movement of pool water returning to the spent fuel pool as much as possible while suppressing overflow due to sloshing. It aims at providing a control device and its manufacturing method.

In order to solve the above problem, the spent fuel pool overflow control device according to the present embodiment is provided with a predetermined interval at a peripheral edge of the spent fuel pool, and is pivoted to the support columns . A water stop plate that is attached to be able to open and closes a space formed between the struts so as to be openable and closable, and restrains the rotation of the water stop plate formed at the end of the strut to the outside of the spent fuel pool. characterized in that it has a protrusion, and a stopper for restricting a predetermined angle rotation of the inner side of the spent fuel pool of the waterstop provided on the floor of the peripheral edge of the spent fuel pool And

Further, in the method for manufacturing the overflow control device for the spent fuel pool according to the present embodiment, a plurality of support columns are provided at predetermined intervals on the peripheral edge of the spent fuel pool, and are rotatably attached to the support columns. In addition, a water stop plate for closing the space formed between the struts so as to be openable and closable is provided, and the rotation of the water stop plate to the outside of the spent fuel pool is restrained by a protrusion formed at the end of the strut. and, wherein the Turkey be restricted to a predetermined angle rotation of the inner spent fuel pool of the waterstop by stop provided on the floor surface around the edge of the spent fuel pool.

  ADVANTAGE OF THE INVENTION According to this invention, the simple and reliable overflow control apparatus which prevents the movement of the pool water which returns to a spent fuel pool as much as possible, suppressing the overflow by sloshing, and its manufacturing method can be provided.

The longitudinal cross-sectional view of the overflow control apparatus which concerns on 1st Embodiment. The perspective view of the overflow control apparatus which concerns on 1st Embodiment. The perspective view of the overflow control apparatus vicinity which concerns on 1st Embodiment. It is a top view of the overflow control apparatus which concerns on 2nd Embodiment, (a) is a figure which shows the state which the water stop plate closed, (b) is a figure which shows the state which the water stop plate opened. It is a top view of the overflow control device concerning the modification of a 2nd embodiment, (a) is a figure showing the state where a water stop plate was closed, and (b) is a figure showing the state where a water stop plate was opened. The longitudinal cross-sectional view of the overflow control apparatus which concerns on 3rd Embodiment. The longitudinal cross-sectional view of the overflow control apparatus which concerns on 4th Embodiment. The perspective view of the overflow control apparatus which concerns on 5th Embodiment.

Hereinafter, an embodiment of an overflow control device for a spent fuel pool and a method for manufacturing the same according to the present invention will be described with reference to FIGS. 1 to 8.
[First Embodiment]
A spent fuel pool overflow control apparatus according to a first embodiment will be described with reference to FIGS. 1 to 3.

(Constitution)
1 to 3, the spent fuel pool 1 is installed in a reactor building (not shown), and the opening of the spent fuel pool 1 is provided on the operation floor 2. The spent fuel pool 1 is filled with pool water 3, and spent fuel racks containing spent fuel are stored in the fuel pool 1 (not shown).

  An overflow control device 4 is installed near the edge of the operation floor 2 so as to surround the spent fuel pool 1. The overflow control device 4 includes a gantry 6 having a plurality of openings 6a, a water stop plate 5 that closes each opening 6a so as to be opened and closed, and a stopper 7. As shown in FIG. 2, the upper end portion of the water stop plate 5 is rotatably attached to the upper portion of the gantry 6 via a hinge or the like, and the water stop plate 5 opens only to the spent fuel pool 1 side. It is configured. On the other hand, a stopper 7 provided at the lower portion of the gantry 6 restricts the water stop plate 5 from rotating outside the spent fuel pool 1. That is, the water stop plate 5 is configured not to open to the operation floor 2 side.

  The height of the gantry 6 can be changed as appropriate. Moreover, in the said embodiment, although the water stop plate 5 is attached to the upper part of the mount frame 6 so that rotation is possible, you may attach the water stop plate 5 to one side part of the mount frame 6 so that rotation is possible. Furthermore, an existing handrail (Patent Document 1) provided at the edge of a conventional spent fuel pool can be used as the gantry 6.

In this overflow control device, first, a gantry 6 having a plurality of openings 6a is provided at the peripheral edge of the spent fuel pool 1, and is attached to the upper part or side part of the gantry 6 so as to be rotatable, and the opening 6a. It is manufactured by providing a water stop plate 5 that can be opened and closed, and a stopper 7 that restricts the rotation of the water stop plate 5 to the outside of the spent fuel pool at the bottom of the gantry 6.
At this time, an existing handrail provided at the peripheral edge of the conventional spent fuel pool 1 can be used as a gantry.

(Function)
In the overflow control device 4 configured as described above, when sloshing occurs during an earthquake and the wave height of the pool water 3 increases at the edge of the spent fuel pool 1, the water pressure of the pool water 3 is outside the spent fuel pool 1. In order to work in the direction (operation floor 2 side), the water stop plate 5 is restrained by the stopper 7 and closed, and the wave rises along the water stop plate 5 but suppresses overflow to the operation floor 2. Can do.

  On the other hand, when a larger earthquake occurs, the pool water 3 may get over the water stop plate 5 and overflow to the outside of the water stop plate 5, that is, the operation floor 2. A part of the overflowing pool water 3 is rebounded by various structures (not shown) installed on the building wall 8 and the operation floor 2 shown in FIG. 3 and returns to the spent fuel pool 1. At that time, the water stop plate 5 opens to the spent fuel pool 1 side by the pressure of the returning pool water 3, and the pool water 3 flows again into the spent fuel pool 1. 1 and 2 show a state in which the water stop plate 5 is opened to the spent fuel pool 1 side.

(effect)
As described above, according to the first embodiment, the overflow amount due to sloshing is suppressed by installing the overflow suppression device 4 higher than the liquid level of the spent fuel pool 1 around the spent fuel pool 1. In addition, since the water stop plate 5 opens only in the direction toward the inside of the spent fuel pool 1, the pool water 3 once overflowed is not prevented from returning to the spent fuel pool 1. Therefore, more pool water 3 can be retained in the spent fuel pool 1 even during a major earthquake than in the case of a conventional fixed water stop plate.

  In addition, since an existing handrail provided at the edge of the spent fuel pool can be used as the gantry 6, it is possible to easily install an overflow control device by a simple incidental work even at an existing nuclear power plant. it can.

[Second Embodiment]
The overflow control apparatus of the spent fuel pool which concerns on 2nd Embodiment is demonstrated with reference to FIG. 4 (a), (b) and FIG. 5 (a), (b). In addition, the same code | symbol is attached | subjected to the structure same as said embodiment, and the overlapping description is abbreviate | omitted.

(Constitution)
The overflow control device 4 according to the second embodiment includes a plurality of support columns 10 installed around the fuel storage pool 1 at predetermined intervals, and is attached to each support column 10 by a hinge or the like so as to be rotatable. It is comprised from the water stop board 9 which closes the space formed between 10 so that opening and closing is possible, and the stopper 11 which has the inclined surface provided in the floor surface. The water stop plate 9 is restrained by the protruding portion 10 a of the support column 10 so as not to rotate in the outward direction of the spent fuel pool 1. On the other hand, with respect to the inside direction of the spent fuel pool 1, the water stop plate 9 is rotated to a predetermined angle by a stopper 11 having an inclined surface.

In the example shown in FIGS. 4 (a) and 4 (b), the water stop plate 9 is pivoted by double opening, but as shown in FIGS. 5 (a) and 5 (b), It may be attached.
Moreover, as the support | pillar 10, the existing handrail provided in the edge part of the conventional spent fuel pool (patent document 1) can be utilized.

(Function)
In the overflow control device 4 configured as described above, when sloshing occurs during an earthquake and the wave height of the pool water 3 increases at the edge of the spent fuel pool 1, the water pressure of the pool water 3 is outside the spent fuel pool 1. In order to work in the direction (operation floor 2 side), the water stop plate 9 is constrained by the protruding portion 10a of the support column 10 and closed, and the wave rises along the water stop plate 9, but does not overflow the operation floor 2. Can be suppressed.

  On the other hand, when the pool water 3 that has passed over the water stop plate 9 and overflowed to the outside of the water stop plate 9, that is, the operation floor 2, returns to the spent fuel pool 1, the water stop plate 5 returns to the water pressure of the pool water 3 that returns. As a result, the pool water 3 flows again into the spent fuel pool 1 by opening a predetermined angle toward the spent fuel pool 1 side. In this way, the water stop plate 9 is restrained at a predetermined angle by the stopper 11 and is therefore always closed against the sloshing wave coming next.

(effect)
According to the second embodiment, by installing the overflow suppression device 4 higher than the liquid level of the spent fuel pool 1 around the spent fuel pool 1, the amount of overflow due to sloshing can be suppressed, Since the water stop plate 9 opens only in the direction toward the inside of the spent fuel pool 1, the pool water 3 that has overflowed once is not prevented from returning to the spent fuel pool 1. Therefore, more pool water 3 can be retained in the spent fuel pool 1 even during a major earthquake than in the case of a conventional fixed water stop plate.

  Moreover, since the existing handrail provided at the edge of the spent fuel pool can be used as the support column 10, it is possible to easily install the overflow control device by a simple incidental work even in the existing nuclear power plant. it can.

[Third Embodiment]
The overflow control apparatus of the spent fuel pool which concerns on 3rd Embodiment is demonstrated with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as said embodiment, and the overlapping description is abbreviate | omitted.

In the overflow control device 4 of the present embodiment, a rubber plate or a sponge material 13 for holding water is provided below the water stop plate 5.
Thereby, since the clearance gap between the water stop board 9 and a floor surface can be block | closed, without preventing rotation of the water stop board 9, the overflow from the fuel storage pool 1 can be suppressed reliably.

[Fourth Embodiment]
The overflow control apparatus of the spent fuel pool which concerns on 4th Embodiment is demonstrated with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as said embodiment, and the overlapping description is abbreviate | omitted.

In the overflow control device 4 according to this embodiment, a weight 14 is provided at the lower end of the water stop plate 5 or an elastic member 15 made of a spring or the like is provided between the lower portion of the water stop plate 5 and the gantry 6 or the column 10. It is said. This elastic member is biased in the direction of closing the water stop plate. The weight 14 and the elastic member 15 may be used in combination.
Thereby, the water stop plate 5 opened by the water pressure of the returning pool water 3 is closed by the action of the weight 14 and / or the elastic member 15 when the magnitude of the water pressure becomes a predetermined value or less.

  By the way, if the wave of sloshing rises while the water stop plate 5 is open, the water stop plate 5 may remain open due to buoyancy, and pool water may overflow on the operation floor 2. According to the embodiment, since the water stop plate 9 is closed by the action of the weight 14 and / or the elastic member 15 when the water pressure of the returning pool water 3 becomes a predetermined value or less, the overflow from the spent fuel pool 1 is suppressed. can do.

  In addition, the closing force of the water stop plate 9 can be appropriately adjusted by adjusting the mass of the weight 14 and / or the spring constant of the elastic member 15. It is also possible to use the weight 14 and / or the elastic member 15 together with the rubber plate or sponge material 13 of the second embodiment. Furthermore, the elastic member 15 can also be applied to the water stop plate 5 that rotates in the lateral direction of the second embodiment.

[Fifth Embodiment]
The overflow control apparatus of the spent fuel pool which concerns on 5th Embodiment is demonstrated with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as said embodiment, and the overlapping description is abbreviate | omitted.

  In the overflow control device 4 of the present embodiment, the space 6 formed in the opening 6a of the overflow control device 4 shown in FIG. 1 or between the columns 10 shown in FIG. 4 is composed of a perforated plate or a mesh (metal mesh). The fence 12 is provided.

  The fence 12 prevents passage of various foreign substances on the operation floor 2 that have been washed away by the pool water 3 and become floating substances, and prevents foreign substances from flowing into the spent fuel pool 1. Since the fence 12 can be used as a stopper, the stopper can be omitted in this embodiment.

  According to the present embodiment, when the pool water 3 that has overflowed once returns, it is possible to minimize the flow of various foreign substances into the spent fuel pool 1, so that the quality of the pool water 3 is deteriorated or used. Fuel damage can be prevented.

  As mentioned above, although the example of the embodiment of the present invention has been described, only a specific example has been illustrated, and the present invention is not particularly limited, and a specific target liquid metal cooling furnace or the like can be changed as appropriate. is there. Further, the actions and effects described in the embodiments and the modifications thereof are only the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to the ones.

DESCRIPTION OF SYMBOLS 1 ... Spent fuel pool, 2 ... Operation floor, 3 ... Pool water, 4 ... Overflow control device, 5 ... Water stop plate, 6 ... Stand, 6a ... Opening part, 7 ... Stopper, 8 ... Wall, 9 ... Stop Water plate, 10 ... post, 10a ... projection, 11 ... stopper, 12 ... fence, 13 ... rubber plate or sponge material, 14 ... weight, 15 ... elastic member.

Claims (9)

A plurality of struts provided at a peripheral edge of the spent fuel pool at predetermined intervals, and a water stop plate that is rotatably attached to the struts and that closes a space formed between the struts so as to be openable and closable. A protrusion formed on an end of the support column for restricting the rotation of the water stop plate to the outside of the spent fuel pool, and the water stop plate provided on a floor surface of a peripheral edge of the spent fuel pool. overflow suppressing apparatus of the spent fuel pool with the rotation of the inner side of the spent fuel pool and having and a stopper for restricting a predetermined angle. Overflow suppressing apparatus of the spent fuel pool of claim 1 Symbol placement which comprises using the existing handrails are provided around the edge of the spent fuel pool as before Ki支 column. The overflow control device for a spent fuel pool according to claim 1 or 2, wherein a rubber plate or a sponge material is attached to a lower portion of the water stop plate. The overflow control device for a spent fuel pool according to any one of claims 1 to 3 , wherein a weight is provided at a lower portion of the water stop plate. Overflow suppressing apparatus of the spent fuel pool according to any one of claims 1 to 4, characterized in that installed an elastic member between the front Ki支 post and the waterstop. Overflow suppressing apparatus of the spent fuel pool according to any one of claims 1 to 5, characterized in that they have installed fence consisting of a mesh or perforated plate in the space between the front Symbol struts. The apparatus for suppressing overflow of a spent fuel pool according to any one of claims 1 to 6, wherein a surface of the stopper that contacts the water stop plate is an inclined surface. A plurality of struts are provided at predetermined intervals on the peripheral edge of the spent fuel pool, and a water stop plate is provided that is rotatably attached to the struts and closes a space formed between the struts so as to be opened and closed. And a stopper provided on the floor surface of the peripheral edge of the spent fuel pool by restraining the rotation of the water stop plate to the outside of the spent fuel pool by a protrusion formed at the end of the support column. method for producing overflow suppressing device of the spent fuel pool, characterized in the Turkey to restrict the rotation of the inner spent fuel pool of the waterstop in a predetermined angle by. The method for manufacturing the overflow control device for a spent fuel pool according to claim 8, wherein an existing handrail provided at a peripheral edge of the spent fuel pool is used as the support column .

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