JP2013250198A - Cooling storage facility for radioactive waste body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cooling storage facilities capable of uniformly and efficiently cooling a waste body housing pipe.SOLUTION: There are provided cooling storage facilities for a radioactive waste body including a storeroom 2 in which a plurality of cylindrical waste body housing pipes 1 housing radioactive waste bodies are arranged, and an air supply duct 4 supplying air to the storeroom and an exhaust duct 5 exhausting air from the storeroom. The storeroom comprises a center region 12 which is connected to the exhaust duct and in which the waste body housing pipes are arranged, and two side regions 11, 13 which are connected to the air supply duct and which are formed across storeroom division plates stood on both sides of the center region. A lower plenum 7 is formed below the center region and side regions.

Description

  Embodiments described herein relate generally to a cooling storage facility for radioactive waste generated in a nuclear power plant or the like.

  A storage for low-level radioactive waste generated in a nuclear power plant is usually formed in a concrete pit constructed underground, and has a structure that includes a cooling air passage and shields radiation.

  In general concrete materials, most of the contained water evaporates at 100 ° C. or more. Therefore, in order to maintain the hydrogen content in moisture effective for shielding radiation, particularly neutrons, the temperature of the storage is 65. It is necessary to keep the temperature at 90 ° C. or lower even at a local high temperature portion, and it is necessary to efficiently remove heat generated from the radioactive waste.

  The radioactive waste is cooled by adopting a natural cooling method based on the head difference between the inlet of the air supply duct and the outlet of the exhaust duct. Cooling air is taken in from the air supply duct installed on the side of the storage and the inside of the storage is cooled. After that, the air is discharged as heated air from the exhaust duct installed on the side of the storage opposite to the air supply duct.

  In the cooling storage facility of Patent Document 1 below, as shown in FIG. 7, the spent fuel storage facility has a horizontally extending shielding wall 60 sandwiched in a reinforced concrete storage housing 50 installed in a semi-underground shape. A storage chamber 70 for storing the canister C is installed in the lower part.

  A cooling air supply passage 80 for introducing cooling air (outside air) and a heated air exhaust passage 90 are provided on both sides of the storage chamber 70, and are introduced from an air supply port 81 formed in the storage housing 50. The cooling air is naturally introduced into the storage chamber 70 from the cooling air supply passage 80, flows in a direction crossing the canister C stored in the storage chamber 70, and then exhausted to the heating air exhaust passage 90. It has become.

JP 11-271493 A

  By the way, in the cooling storage facility described in the above-mentioned prior art document, the cooling air introduced from the air supply port 81 mainly flows in the storage chamber 70 in a direction crossing the canister C, so that the cooling air flows on the surface of the canister C. Cooling unevenness occurs between the part that directly hits and the part that does not, and the cooling air becomes a circulating flow in the storage chamber and is not smoothly exhausted, resulting in locally high and low temperatures and uneven cooling. There was a problem. Further, when cooling air directly hits the surface of the canister C, there is a problem that pressure loss occurs and cooling efficiency is lowered.

  In order to solve the above problems, the cooling storage facility according to each embodiment includes a storage in which a plurality of cylindrical waste storage pipes storing radioactive waste are disposed, an air supply duct for supplying air to the storage, and A radioactive waste body cooling storage facility comprising an exhaust duct for exhausting air from the storage, wherein the storage is connected to the exhaust duct and a central region in which the waste storage pipe is disposed, and the air supply duct And two side regions formed through storage partition plates erected on both sides of the central region, and a lower plenum is formed below the central region and the side region .

  Each embodiment described below is made in order to solve the above-mentioned problem, and an object thereof is to provide a cooling storage facility capable of cooling the waste storage tube uniformly and efficiently.

The schematic diagram of the cooling storage equipment which concerns on 1st Embodiment. The fragmentary sectional view of the cooling storage equipment concerning a 1st embodiment. The schematic diagram of the cooling storage equipment which concerns on 2nd Embodiment. The partial schematic diagram of the cooling storage equipment which concerns on 3rd Embodiment. Sectional drawing of the cooling storage equipment which concerns on 3rd Embodiment. Sectional drawing of the storage which concerns on 3rd Embodiment. Sectional drawing of the conventional cooling storage equipment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
(First embodiment)
A cooling storage facility according to a first embodiment of the present invention will be described with reference to FIGS. 1, 2, and 6.

FIG. 1 is a schematic view showing the entire cooling storage facility according to the present embodiment, FIG. 2 is a partial sectional view of the cooling storage facility, and FIG. 6 is a sectional view of a modified example of the storage.
In FIG. 1, the cooling storage facility includes a storage 2, a derivative 10 formed on the outer wall surface of the storage 2, an air supply duct 4, and an exhaust duct 5.

The storage 2 is composed of three regions formed by storage partitions 6 and 6 and a lower plenum 7.
The three regions are a central region 12 in which the upper ends of the plurality of waste storage tubes 1 are fixed to the storage ceiling 8 and the lower ends are arranged in a free state, and two sides formed on both sides adjacent to the central region 12. It is formed of partial areas 11 and 13.

  An air inlet 21 to the side regions 11 and 13 is formed on the wall surface on the air supply duct 4 side of the storage 2, and an air outlet 23 from the central region 12 is formed on the wall surface on the exhaust duct 5 side of the storage 2. Yes.

The waste storage tube 1 is cylindrical, and a large number of radioactive wastes (not shown) are stored in a sealed state.
The lower plenum 7 is a gap through which the central region 12 and the side regions 11 and 13 communicate with each other.

The height of the storage partition plates 6, 6 is substantially the same as the height of the waste storage tube 1, and the method of attaching to the storage ceiling 8 is the same as that of the waste storage tube 1.
In FIG. 1, the number of waste storage tubes 1 is partially omitted, but in reality, a large number of waste storage tubes 1 are arranged in the central region 12 at appropriate intervals.

The air supply duct 4 is provided with an air supply port 3 that is an intake port for cooling air, and the overall duct shape is such that the cooling air rising from the air supply port 3 is U-turned and descends. is there.
The air supply duct 4 is connected to an air inlet 21 formed in the side regions 11 and 13.

The air inlet 21 has a vertically long and substantially rectangular shape, and is formed from the upper ends of the side regions 11 and 13 to the upper end of the lower plenum 7.
One end of the exhaust duct 5 is connected to an air outlet 23 having a horizontally long rectangular shape in the central region at the lower part of the ceiling 8 of the storage 2.

  The exhaust duct 5 is provided with an exhaust port 22 for discharging the air whose temperature is increased to the outside, and the entire duct shape is a flow in which the air discharged from the air outlet 23 of the storage 2 is bent at a substantially right angle and rises. It is a shape like this.

  The derivative 10 serves as a guide for efficiently dividing and guiding the cooling air flowing into the storage 2 to the air introduction port 21, and has a height substantially the same as that of the air introduction port 21. As shown in FIG. 2, in the present embodiment, the cross section is triangular. However, any shape such as a cross-sectional airfoil shape can be adopted as long as the air flow can be smoothly guided.

The operation of the present embodiment configured as described above will be described.
The cooling air introduced from the air supply port 3 in accordance with the heat generation of the waste container 1 (the flow direction schematically shown by dotted lines and arrows in FIGS. 1 and 2) is the river of the air supply duct 4. At the bottom, it changes direction horizontally. The cooling air whose direction has been changed is guided by being divided into the derivative 10, and the inflow speed is reduced and flows from the air inlet 21 toward the side regions 11 and 13 of the storage 2.

  The two-way cooling air that has flowed into the side regions 11 and 13 then changes direction in the vertical direction and flows downward to flow into the central region 12 from the lower ends of the storage partition plates 6 and 6 through the lower plenum 7. To do. Thereafter, the cooling air rises along the waste storage tube 1 without traversing the waste storage tube 1, changes its direction horizontally by the ceiling 8, passes through the exhaust duct 5, and is finally discharged from the exhaust port 22. The

In this way, the cooling air changes direction in the lower part of the air supply duct 4 and then changes in the two side areas 11 and 13 before reaching the central area 12 of the storage 2. At this time, the flow velocity on the outside is fast due to the general flow nature of the bend, and it is fast on the supply side in the first direction change and fast on the exhaust side in the later direction change.
Therefore, the inflow speed of the cooling air flowing into the central region 12 is averaged, and the waste body storage tube 1 can be efficiently cooled without being a circulation flow in the central region 12.

In the central region 12, the cooling air rises along the waste storage tube 1 without traversing the waste storage tube 1, so that no pressure loss occurs and the waste storage tube 1 is efficiently and uniformly cooled. be able to.
Furthermore, since the inflow speed of the cooling air is reduced by the derivative 8, the occurrence of pressure loss can be prevented.

(Second Embodiment)
Next, a cooling storage facility according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a schematic diagram illustrating the entire cooling storage facility according to the present embodiment.

  This embodiment is different from the first embodiment in that the air supply port 3 is provided at two locations and the air supply duct 4 is provided independently in two systems, on the respective wall surfaces of the side regions 11 and 13. The point which provided the guide plate 9 which guides the flow of cooling air, and the point which removed the derivative | guide_body 10. FIG.

In FIG. 3, two flows of cooling air are schematically shown by two dotted lines.
As in the first embodiment, in FIG. 3, the number of waste storage tubes 1 is partially omitted, but in reality, a large number of waste storage tubes 1 are arranged in the entire storage 2 at appropriate intervals.

According to the present embodiment, as in the first embodiment, the inflow speed of the cooling air into the central region is averaged and rises along the waste storage tube 1 to be efficiently cooled. By providing the air inlet 3 at two locations and providing the air supply duct 4 independently in two systems, the cooling air efficiently flows smoothly through the air supply duct 4 without pressure loss, and the side region 11, 13 can flow directly. Further, by providing the guide plates 9 for guiding the flow of the cooling air on the respective wall surfaces of the side regions 11 and 13, the flow in the side regions 11 and 13 can be smoothly curved by the guide plates 9. It can flow.
In the first embodiment as well, guide plates 9 for guiding the flow of cooling air may be provided on the respective wall surfaces of the side regions 11 and 13.

(Third embodiment)
A cooling storage facility according to a third embodiment of the present invention will be described with reference to FIGS. 4, 5, and 6.
FIG. 4 is a partial schematic view of the cooling storage facility according to the third embodiment, FIG. 5 is a sectional view of the cooling storage facility, and FIG. 6 is a sectional view of the storage.

  The present embodiment is different from the first embodiment in that a rectangular baffle plate 17 is provided on the upper portion of the lower plenum 7 of the storage 2, and the air supply duct 4 is connected to the lower plenum 17 and a housing 18. And the storage partition plate 6 and the derivative 10 of the storage 2 are removed.

  As in the first embodiment, in FIG. 4, the number of the waste body storage pipes 1 is partially omitted, but actually, the whole area is appropriately adjusted except for the installation area of the baffle plate 17 from the wall surface of the storage 2. Are arranged at intervals of.

The baffle plate 17, which is substantially rectangular as a whole, has an outer edge in contact with the four inner wall surfaces of the storage 2, and the inner edge is provided close to the storage area of the waste storage pipe 1.
The casing 18 is a reinforcing member that maintains the strength of the air supply duct 4 and also has a start end not shown and an acute end as shown in FIG. 4 so that the inflowing cooling air can be directed to the central region 12. However, the shape of the start end and the tip may be any shape that does not hinder the flow of air and hardly generates pressure loss.

  Further, in the present embodiment, as shown in FIG. 5, an air supply duct R 15 is provided at a bent portion of the air supply duct 4, and an inlet louver is provided in the lower horizontal portion of the air supply duct 4 to the vicinity of the casing 18. 19, outlet louvers 24 are formed in the upper horizontal portion of the exhaust duct 5 to take in external air in order to cool the high-temperature air.

The operation of the present embodiment configured as described above will be described with reference to FIGS.
The cooling air taken in from the air supply port 3 descends the air supply duct 4 and flows into the lower plenum 9 according to the heat generation of the waste body storage tube 1, and then along the waste body storage tube 1 in the storage 2. It rises, flows along the ceiling 8 of the storage 2, passes through the exhaust duct 5, and is discharged from the discharge port 33.

  At this time, since the corresponding air flow is generated in the exhaust duct 5, the discharged air is at a high speed, so that the flow velocity of the air is increased at the abutting portion at the right end of the lower plenum 7 and the exhaust duct 5 is raised. It will be. As a result, in the inlet louver 19, air tends to hardly flow in the forward flow in the uppermost flow path.

  However, in this embodiment, as shown in FIG. 4, between the storage 2 and the lower plenum 7, the space around the wall surface of the storage 2 and the waste storage pipe 1 is closed with a rectangular baffle plate 17, and By narrowing the shape of the casing 18 provided at the joint between the air supply duct 4 and the lower plenum 7 toward the tip, a fast flow flowing from the air supply duct 4 can be guided toward the waste body storage tube 1. Therefore, similarly to the first embodiment described above, the unbalance of the air flowing to the storage 2 is reduced, and the waste storage tube 1 can be efficiently cooled.

  Since the air supply duct R 15 is installed at the lower horizontal portion of the air supply duct 4, the cooling air flowing into the storage 2 becomes smooth and is accelerated by the air flowing in from the inlet louver 19, and the front row of the waste body storage pipe 1. Therefore, the imbalance of the air flowing to the storage 2 is reduced, and the waste storage tube 1 can be efficiently cooled.

  Therefore, according to the present embodiment, the rectangular baffle plate 17, the housing 18, and the air supply duct 15 reduce the unbalance of the air flowing to the storage 2, and cool the waste body storage tube 1 efficiently with cooling air. can do.

  In the present embodiment, as shown in FIG. 6, the storage tube partition plate 14 having a length from the vicinity of the lower end of the waste storage tube 1 to the vicinity of the central portion in the height direction of the waste storage tube 1 is provided in the central region 12 of the storage 2. If is installed, the flow distribution in the storage 2 can be made more uniform.

Moreover, in the 1st-3rd embodiment, the exhaust duct 5 can be provided with the housing which is not shown in figure as a reinforcement member near the connection part with the store | warehouse | chamber 2. As shown in FIG.
In addition, the 1st-3rd embodiment is common at the point of the cooling system which cooling air rises along the waste body storage pipe 1, and the common subject which cools the waste body storage pipe 1 uniformly and efficiently. Have.

  Moreover, although the storage pipe partition plate 14 shown in FIG. 6 is also applied to the central region of the first and second embodiments, a part of the storage pipe partition plate 14 overlapping with the storage partition plates 6 and 6 is used in that case. Can be removed.

  In each of the above embodiments, it is important for the storage partition plate 6 to divide the interior of the storage 2 into the side regions 11 and 13 and the central region 12, but for example, the storage partition plate 6 may be inclined in the vertical direction. The horizontal cross-sectional shape can be corrugated or mountain-shaped, or the surface can be uneven.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, changes, and combinations can be made in consideration of the technical common knowledge of those skilled in the art without departing from the gist of the invention. It can be carried out. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Waste body storage pipe, 2 ... Storage, 3 ... Air inlet, 4 ... Air supply duct, 5 ... Exhaust duct, 6 ... Storage partition plate, 7 ... Lower plenum, 8 ... Storage ceiling, 9 ... Guide plate, 10 Derivative, 11, 13 ... Side region, 12 ... Central region, 14 ... Storage pipe partition plate, 15 ... Air supply duct areal, 17 ... Baffle plate, 18 ... Housing, 19 ... Inlet louver, 20 ... Two systems of supply Air duct, 21 ... Air inlet, 22 ... Exhaust port, 23 ... Air outlet, 24 ... Outlet louver, 50 ... Storage housing, 60 ... Shielding wall, 70 ... Storage room, 80 ... Cooling air supply path, 81 ... Air supply port, 90 ... heated air exhaust passage.

Claims (9)

Cooling of radioactive waste including a storage in which a plurality of cylindrical waste storage pipes storing radioactive waste are disposed, an air supply duct for supplying air to the storage, and an exhaust duct for exhausting air from the storage A storage facility,
The storage is formed through a central region connected to the exhaust duct and disposed with the waste storage pipe, and a storage partition plate connected to the air supply duct and erected on both sides of the central region. A radioactive waste body cooling storage facility comprising a plurality of side regions, wherein a lower plenum is formed at a lower portion of the central region and the side regions.   2. The radioactive waste body cooling storage facility according to claim 1, wherein an air inlet is formed in the side region from the upper end of the same region to the upper end of the lower plenum.   The radioactive waste body cooling storage facility according to claim 1 or 2, wherein at least one guide plate for guiding air is provided in the side region.   The radioactive waste according to any one of claims 1 to 3, wherein a derivative that divides and guides an air flow into the side region is provided on a wall surface of the storage facing the air supply duct. Cold storage equipment.   The said waste_air | air_supply duct is comprised by 2 systems, and is connected with the said side area | region, respectively, The cooling storage equipment of the radioactive waste body in any one of Claim 1 to 3 characterized by the above-mentioned.   6. The radioactive waste body cooling storage facility according to claim 1, wherein a vertical storage pipe partition plate is provided in the central region. A radioactive waste comprising a storage in which a plurality of cylindrical waste storage pipes storing radioactive waste are disposed, an air supply duct for supplying air to the storage, and an exhaust duct for exhausting air from the storage In the cooling storage facility of
The air supply duct is connected to the lower plenum, and has a baffle plate having a predetermined width horizontally provided below the inner wall surface of the storage, and a lower plenum formed at a lower portion of the baffle plate, A cooling waste storage facility for radioactive waste, which is connected to the air supply duct.   8. The radioactive waste body cooling storage facility according to claim 7, wherein a casing for guiding air to the waste body storage pipe is provided in the air supply duct.   9. The radioactive waste body cooling storage facility according to claim 7, wherein a storage pipe partition plate is provided vertically in the storage.

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