JP2012122818A - Sloshing prevention device of fuel storage pool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact immovable type sloshing prevention device suppressing sloshing generated by earthquake or the like without obstructing a space for a fuel assembly stored in a spent fuel pool and preventing the overflow of pool water to a floor.SOLUTION: A sloshing prevention device of a fuel storage pool A provided in a nuclear power plant which is attached to a wall surface at a height equal to or lower than a free water surface G of the pool water includes: a connecting member provided on the pool wall surface at a height equal to or lower than the free water surface G; a plurality of guide members fixed to the lower face of the connecting member in the perpendicular direction to the free water surface of the pool water and the pool wall surface; and a barrier member fixed parallel to the wall surface, the barrier member having a plurality of holes at an end portion of the connecting member facing the free water surface G of the pool, and the tip of the barrier member being provided at a height equal to or higher than of the free water surface G of the pool water.

Description

  The present invention relates to a sloshing that suppresses sloshing of pool water caused by an earthquake or the like in a fuel storage pool provided in a nuclear power plant, and prevents the pool water from overflowing to the floor around the pool including the fuel replacement floor. The present invention relates to a prevention device.

  When a fuel storage pool provided in a nuclear power plant is impacted by an earthquake or the like, sloshing occurs in which the pool water stored in the pool swings.

  The fuel storage pool has a depth more than twice the length of the fuel assembly, and can be moved from the fuel storage pool to the core without taking the fuel assembly into the air. The upper part of the fuel storage pool is always open, and depending on the magnitude of the earthquake, the pool water exposed to radioactive materials due to sloshing may leak to the outside.

  As a method of suppressing the above sloshing, there is a conventional method of installing a flat plate under the water surface in parallel to the water surface. However, if a flat plate is installed, the fuel assembly cannot be stored under the flat plate, and the storage space is reduced. In order to solve this problem, for example, the horizontal position of the resistance member is made of a flat member whose one end is rotatably supported by a support shaft provided along a wall surface below the free water surface of the liquid storage tank. A first stopper that prevents the rotation further upward, a second stopper that prevents the rotation downward from a position where an acute angle is sandwiched between the resistance member and the inner wall (see, for example, Patent Document 1), There is a flat plate installed in the vicinity of the water surface of a container for storing liquid, and this flat plate is supported by a support member so as to be rotatable and fixed (see, for example, Patent Document 2).

JP 2009-216538 A JP-A-8-101296

  In the above conventional example, the anti-sloshing means is rotatably installed, and the flat plate hangs vertically along the pool wall surface so as not to disturb the storage space for the fuel assembly during normal operation. In the event of an earthquake, the flat plate rotates from its normal position in order to exert the function of the anti-sloshing device, and the water surface and the flat plate are fixed in parallel to suppress sloshing in the storage tank. However, these anti-sloshing devices have moving parts, so the moving parts are likely to break down or corrode, and the plate may not drive when an earthquake occurs and may not perform its original function. It may be damaged by receiving, and the components of the device may fall to the bottom of the fuel pool.

  The present invention solves the above-described problem, and suppresses sloshing caused by an earthquake or the like without restricting the storage space for the fuel assembly in the spent fuel pool, and prevents the pool water from overflowing to the floor. A non-movable anti-sloshing device is provided.

  The present invention relates to a sloshing prevention device attached to a wall surface of a fuel storage pool provided in a nuclear power plant, wherein a connecting member is provided in parallel with the wall surface along a wall surface below the free water surface of the fuel storage pool, and the pool bottom surface of the connecting member A plurality of guide members are provided perpendicularly to the free water surface and the fuel storage pool wall surface on the lower surface opposite to the front surface, a barrier member is provided parallel to the pool wall surface at the free water surface side end of the connecting member, and the tip of the barrier member is It protrudes beyond the free water surface, and guides the rising water flow at the time of sloshing by the guide member and the barrier member and attenuates the kinetic energy.

  In the anti-sloshing device for the fuel storage pool, the plurality of guide members are arranged on the lower surface of the connecting member at equal intervals with a predetermined gap.

  Further, in the anti-sloshing device for the fuel storage pool, the connecting member is provided with a plurality of holes through which a part of the rising water flow is distributed and passed.

  In the anti-sloshing device for the fuel storage pool, a surface resistance portion that increases resistance to the rising water flow is provided on the surface of the guide member.

  Furthermore, in the anti-sloshing device for the fuel storage pool, an uneven portion for increasing the surface area with the rising water flow is provided as the surface resistance portion.

  According to the present invention, the anti-sloshing device is attached to the pool wall below the free water surface of the pool water in the fuel storage pool, and the plurality of guide members are coupled to the free water surface and the pool wall surface vertically by the connection member. In addition, by providing a barrier member parallel to the pool wall surface and the tip above the free water surface, a compact sloshing prevention device that prevents sloshing and prevents overflow while ensuring sufficient storage space for the fuel assembly. Can be realized.

It is a schematic diagram which shows the installation condition of the sloshing prevention apparatus of Example 1 of this invention. It is a top view of the sloshing prevention device of Example 1 installed in the fuel pool. It is a front view of the sloshing prevention device of Example 1 of the present invention. It is the sectional view on the aa line of FIG. It is the bb sectional view taken on the line of FIG. It is a front view of the sloshing prevention device of Example 2 of the present invention. It is a schematic diagram of the guide member of the sloshing prevention device of Example 2 of the present invention.

  Embodiments of the anti-sloshing device of the present invention will be described below with reference to the drawings and examples. In addition, the same code | symbol is attached | subjected to the equivalent component through each drawing.

  FIG. 1 shows a sloshing prevention device according to a first embodiment of the present invention. The fuel storage pool A holds pool water B, and a fuel assembly F is placed on the bottom surface E of the pool. G is the free surface of pool water B. C is a pool wall surface, and D is a fuel replacement floor provided on the floor around the pool. The portion of the fuel replacement floor D surrounding the pool water B forms a raised peripheral edge.

  The anti-sloshing device 1 is fixed to the peripheral portion of the fuel replacement floor D by an arbitrary fixing means via the saddle-shaped support member 5. The anti-sloshing device 1 is made of a material having excellent corrosion resistance such as a stainless steel plate. In the anti-sloshing device 1, 2 is an elongated connecting member provided parallel to the pool wall surface C, 3 is a guide member, and 4 is an elongated barrier member provided in the vertical direction parallel to the pool wall surface C. The guide member 2 is suspended from the peripheral edge of the fuel replacement floor D by two vertical support members 5 in the pool water B in parallel with the pool bottom surface E, and a plurality of guides are directed toward the pool bottom surface E on the lower surface thereof. The plates 4 are provided parallel to each other and perpendicular to the pool wall surface C. The barrier member 4 rises upward from the edge opposite to the pool wall surface C of the connecting member 2 and protrudes above the water surface beyond the free water surface G.

  As shown in FIG. 2, the plurality of anti-sloshing devices 1 are installed along the pool wall C over the entire circumference of the fuel storage pool A.

  As shown in FIG. 3, the anti-sloshing device 1 has a plurality of guide members 3 fixed on the lower surface of the connecting member 2 facing the pool bottom surface E in a direction perpendicular to the free water surface G and the pool wall surface C. The gap P between the guide members 3 is set to an optimal dimension so that pool water can pass through and the pool water can be decelerated by being given frictional resistance between the guide members 3 and the like. By arranging the guide members 3 at equal intervals in this way, a uniform anti-sloshing effect can be obtained over the entire length of the anti-sloshing device.

  A barrier member 4 is fixed to the tip of the surface of the connecting member 2 facing the free water surface G of the pool water so as to be parallel to the pool wall surface C and at one end equal to or greater than the free water surface G of the pool. A plurality of holes 7 through which pool water can pass are formed in the barrier member 4.

  As shown in FIGS. 4 and 5, the rising water flow S generated by the sloshing and flowing along the pool wall surface C flows through the gap P between the guide members 3. At this time, when the guide member 3 and the pool water come into contact with each other, a fluid frictional drag is generated, and the kinetic energy of the rising water flow S can be reduced. Thereafter, the water flow flows along the barrier member 4. At this time, the rising water flow S does not directly touch the pool wall surface C because the barrier member 4 protrudes above the free water surface. Therefore, it becomes possible to suppress overflow effectively. Moreover, when a part of pool water passes the hole 7 of the barrier member 4, the energy of the ascending water flow S can be further reduced.

  In the first embodiment, the guide member has a plurality of flat plates arranged at a predetermined interval to realize smooth ascending water flow guidance and attenuation. Various other specific shapes can be used for the guide member. Basically, the guide member can smoothly guide the rising water flow and can effectively attenuate the kinetic energy of the rising water flow. Good.

  Thus, the anti-sloshing device of Example 1 has a structure that disperses and reduces the energy of the rising water flow S at a plurality of portions, so there is no need to take a large installation area in the horizontal direction with respect to the pool wall surface C. Sloshing can be effectively suppressed while ensuring sufficient storage space for the fuel assembly F, and overflow can be prevented.

  Similarly to the hole 7 of the barrier member 4, a hole may be provided in the connecting member 2 to attenuate the energy of the rising water flow S.

  FIG. 6 shows a front view of the sloshing prevention device 10 according to the second embodiment of the present invention. By installing a large number of concave and convex portions 16 as shown in FIG. 7 as surface resistance portions that increase the resistance to the rising water flow on the surface of the guide member 13 attached to the lower surface facing the pool bottom surface E of the connecting member 12, The contact area between the rising water flow S and the guide member 13 can be increased. As a result, the energy of the rising water flow can be greatly consumed and attenuated by the concavo-convex portion 16, and sloshing can be effectively prevented. The height of the concavo-convex portion 16 is preferably a height that does not contact the adjacent protrusion from the viewpoint of increasing the contact area with the rising water flow. The shape of the concavo-convex portion 16 is not limited to a square but can be a cross section such as a semicircle or a triangle.

DESCRIPTION OF SYMBOLS 1, 10: Sloshing prevention apparatus 2, 12: Connecting member 3, 13: Guide member 4, 14: Barrier member 5: Vertical support member 16: Uneven part A: Fuel storage pool B: Pool water C: Pool wall surface D: Fuel replacement floor E: Pool bottom F: Fuel assembly G: Free water surface P: Clearance

Claims (5)

In the anti-sloshing device attached to the wall surface of the fuel storage pool provided in the nuclear power plant,
A connecting member is provided in parallel with the wall surface below the free water surface of the fuel storage pool, and a plurality of guide members are provided on the lower surface of the connecting member facing the pool bottom surface with respect to the free water surface and the fuel storage pool wall surface. Provided vertically, a barrier member is provided parallel to the pool wall surface at the free water surface side end of the connecting member, the tip of the barrier member protrudes beyond the free water surface, and the guide member and the barrier member An anti-sloshing device for a fuel storage pool, characterized by guiding an ascending water flow and attenuating kinetic energy.   2. The anti-sloshing device for a fuel storage pool according to claim 1, wherein the plurality of guide members are arranged on the lower surface of the connecting member at regular intervals with a predetermined gap. .   3. The anti-sloshing device for a fuel storage pool according to claim 1, wherein the connecting member is provided with a plurality of holes through which a part of the rising water flow is distributed and passed.   4. The fuel storage pool sloshing prevention device according to claim 1, wherein a surface resistance portion that increases resistance to the rising water flow is provided on a surface of the guide member. 5. Storage pool anti-sloshing device.   5. The anti-sloshing device for a fuel storage pool according to claim 4, wherein an uneven portion for increasing a surface area with the rising water flow is provided as the surface resistance portion.

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