JP2009115649A - Device for suppressing sloshing in fuel storage pool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress fuel storage pool water from being sloshed even in a large scale of earthquake to prevent the pool water from overflowing, without worsening an efficiency of fuel replacement work. <P>SOLUTION: This device for suppressing sloshing includes a plurality of vertical plates of dividing grid-likely an upper space of a fuel storage pool, a plurality of horizontal plates provided in respective lower parts of the vertical plates and turnable vertically, and an opening and closing door provided in side end parts of one-parts of the vertical plates to be openable and closable. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  It is known that a spent fuel storage pool installed in a nuclear power plant generates a so-called sloshing phenomenon in which the pool liquid level fluctuates due to vibration caused by an earthquake. At that time, if the liquid level in the pool rises above a certain level, the pool water may overflow to the floor.

  Even if the pool water sways and the water level rises and the floor overflows, if it is below a certain amount, it stays on the floor and is guided and stored in the drain sump tank on the lowest basement floor So it will not overflow down the floor.

  However, in the unlikely event of a large-scale earthquake, this amount may be exceeded, and the drain sump tank on the bottom basement floor has a small capacity. The possibility of affecting important equipment cannot be denied.

  For this reason, as a conventional technique related to measures for preventing overflow due to sloshing, a rotatable flat plate or an openable / closable lid is installed in the vicinity of the liquid surface of the pool for storing liquid, and in the event of an earthquake, water is A technique (Patent Document 1) is known that prevents the occurrence of the sloshing phenomenon by preventing the movement of the wave and suppressing the growth of the wave height.

In addition, as other conventional techniques, a vertical or horizontal standing wall is provided in the vicinity of the edge of the pool to prevent the pool water from overflowing and swinging (Patent Document 2), and the pool water is divided into horizontal partition plates. A technique (Patent Document 3) that prevents the occurrence of the sloshing phenomenon by dividing the pool internal space into a plurality of cells by a vertical partition plate is known.
Japanese Patent Laid-Open No. 8-101296 JP 2006-329799 A JP 2007-176595 A

In the above-described conventional technology, the member installed as a sloshing suppression and overflow countermeasure is provided only at the pool edge, so it is difficult to prevent the occurrence of sloshing reincarnation during a large-scale earthquake (Patent Documents 1 and 2). Moreover, since these members obstruct the fuel exchange work, it is necessary to remove a part of them each time, and the work efficiency of the fuel exchange is lowered.
In addition, covering the entire pool water surface with a lid requires a large-scale lid member and a lid driving mechanism, which is not realistic from the viewpoint of operation reliability and cost (Patent Document 1).

  Further, the anti-sloshing mechanism described in Patent Document 3 is applied to a tank facility such as an oil storage tank, and is installed in a spent fuel storage pool of a nuclear power plant because a plurality of fixed partition plates exist in the water. In some cases, the fuel change operation itself cannot be performed.

  In order to solve the above-described problems, the present invention aims to prevent the overflow of pool water by suppressing the sloshing of spent fuel storage pool water even in the event of a large-scale earthquake without impairing the efficiency of refueling work. To do.

  In order to solve the above problems, a sloshing suppression device according to the present invention is provided with a plurality of vertical plates that divide the upper space of the fuel storage pool into a lattice shape, and is provided at the lower portion of the vertical plates and is rotatable in the vertical direction. A plurality of horizontal plates and an openable / closable door provided at a side end portion of a part of the vertical plates are provided.

  ADVANTAGE OF THE INVENTION According to this invention, the sloshing of fuel storage pool water can be suppressed and the overflow of pool water can be prevented also in the case of a large-scale earthquake, without impairing the efficiency of a fuel exchange operation.

Hereinafter, an embodiment of a sloshing suppression device for a fuel storage pool according to the present invention will be described with reference to FIGS.
In FIG. 1A, a plurality of spent fuel racks 2 for storing spent fuel are installed at the bottom of a fuel storage pool 1 in which spent fuel is stored. A sloshing suppression device 20 according to the present invention is provided.

  The sloshing suppression device 20 includes a plurality of vertical plates 3 and horizontal plates 4, an opening / closing door 5, and a support column 6. The vertical plate 3 and the horizontal plate 4 are light, high-strength, high-corrosion-proof metal (alloy) or resin flat plates.

  In the sloshing suppression device 20, a plurality of vertical plates 3 are combined in a lattice shape, and a horizontal plate 4 is attached to the lower ends of some of the vertical plates. The sloshing suppression device 20 composed of the vertical plate 3 and the horizontal plate 4 is supported by the support column 6 standing from the bottom of the pool at the lattice points of the vertical plate. Further, a fixing portion 7 is provided on one side or more of the sloshing suppression device 20 and is fixed to the upper end of the pool side wall of the floor 12.

  An opening / closing door 5 is provided at a side end portion of a part of vertical plates constituting the lattice, and the opening / closing door 5 is operated to be opened and closed by a wire 8 driven by a driving device 9a made of, for example, an electric motor (see FIG. 1 (a), FIG. 2).

  Further, all or a part of the horizontal plate 4 is structured such that it can be rotated vertically by the wire 8 and the driving device 9b, in the present embodiment, vertically downward (FIG. 1 (a), FIG. 3).

  In FIG. 1A, the open / close door 5 is shown in a partially opened state. Further, although only one drive device 9a and 9b is shown, this is merely an example, and a plurality of drive devices are provided as appropriate according to the location of the member that opens and closes and rotates.

  In the sloshing suppression device 20 having the above-described configuration, the open / close door 5 is normally closed and the horizontal plate 4 is maintained in a horizontal state, but is driven by control signals 11a and 11b from the fuel exchanger process computer 10 at the time of refueling. The devices 9a and 9b drive the wire 8, and the vertical plate 3 and the horizontal plate 4 at necessary positions are automatically rotated horizontally or vertically downward (FIGS. 2 and 3).

Thus, according to the sloshing suppression device 20 according to the present invention, the spent fuel pool is divided into a plurality of grids by the vertical plate 3, and the horizontal plate 4 is installed below the vertical plate 3. Therefore, the occurrence of sloshing phenomenon during a large-scale earthquake can be suppressed, and the possibility of pool overflow can be greatly reduced. It will not hinder the replacement work.
Of course, the horizontal plate 4 may be provided at the lower end of the vertical plate so as to cover the entire pool, and the sizes of the vertical plate 3 and the horizontal plate 4 can be freely changed.

(A) is a top view of the sloshing suppression device concerning the present invention, (b) is an AA sectional view of (a), and (c) is a BB sectional view of (a). The top view which shows the structure of the vertical board which has the door which concerns on this invention. The side view which shows the structure of the rotatable horizontal board which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel storage pool, 2 ... Used fuel rack, 3 ... Vertical plate, 4 ... Horizontal plate, 5 ... Opening / closing door, 6 ... Post, 7 ... Fixed part, 8 ... Wire, 9a, 9b ... Drive apparatus, 10 ... Fuel exchanger process computer, 11a, 11b ... control signal, 12 ... floor, 20 ... sloshing suppression device.

Claims (5)

  A plurality of vertical plates that divide the upper space of the fuel storage pool into a grid, a plurality of horizontal plates that are provided below the vertical plates and that can rotate in the vertical direction, and a side edge of some of the vertical plates A sloshing suppression device for a fuel storage pool, comprising: an openable / closable door provided.   2. The sloshing suppression device for a fuel storage pool according to claim 1, wherein the open / close door of the vertical plate is normally closed and is automatically controlled to be opened by a signal from a fuel changer process computer at the time of fuel change. .   3. The fuel storage according to claim 1, wherein the horizontal plate is supported in a horizontal direction in a normal state, and is automatically rotationally controlled vertically downward by a signal from a fuel changer process computer at the time of refueling. Pool sloshing suppression device.   The sloshing suppression device for a fuel storage pool according to any one of claims 1 to 3, wherein the opening and closing door of the vertical plate and the rotatable horizontal plate are operated by a wire and a driving device.   The sloshing suppression device for a fuel storage pool according to any one of claims 1 to 4, wherein at least one side of the vertical plate is fixed to an upper end of a pool side wall of the floor by a fixing portion.

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