JP3643682B2 - Storage container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates generally to storage containers, and more particularly to containers that are particularly suitable for storage of radioactive materials such as spent nuclear fuel and highly radioactive vitrified bodies.
[0002]
[Prior art]
The structure of a radioactive material storage container according to the prior art will be described with reference to FIG. 3. The storage container 1 is composed of a container body 2 and a lid 3 connected to each other by a welded portion 4. In addition, the radioactive substance 5 as described above is accommodated and stored. In the storage container 1, the internal increased pressure, a load due to an impact such as an earthquake, an external load, and the like are received by the container body 2, the lid body 3, the welded portion 4, and the like.
[0003]
When performing an optimized design such as the amount of material to be used with respect to the increased pressure inside the container as described above, a load due to an impact such as an earthquake, or an assumed design load due to an external load, the container body 2 and the lid 3 Needless to say, the welded part 4 is required to have the same strength as the container body 2.
[0004]
[Problems to be solved by the invention]
Therefore, when trying to improve the structural strength of the storage container 1, it is necessary not only to increase the plate thickness of the container body 2 and the lid body 3, but also to increase the depth of penetration in the welded portion 4. The increase in cost, especially the increase in welding work time, has led to a considerable cost increase.
The present invention has been made in order to eliminate the above-described drawbacks of the prior art, and the object thereof is a storage container that does not require deep penetration of the welded portion and can consequently suppress an increase in material. Is to provide.
[0005]
[Means for Solving the Problems]
To this end, the reservoir according to the present invention, a storage container made of the inner box for storing a substance to be stored, an outer box which is disposed in contact with the outer peripheral surface of the inner box a is, the outer box comprises a lower hoop strength member being disposed adjacent to each other at the lower surface of the upper hoop strength member and / or inner box is juxtaposed adjacent to the upper surface of the inner box, the upper circumferential direction Combined with a plurality of axial strength members fixed to the strength member and / or the lower circumferential strength member and arranged at equal intervals around the side surface of the inner box, and grooves formed in each of these axial strength members It consists of the frame structure which consists of the side surface direction strength member made. Incidentally, the axial strength member of the frame body structure, preferably fixed to the inner box.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts, and the present invention is a storage container for radioactive materials. Although the case where it applies to is demonstrated below, it cannot be overemphasized that it is not limited to this.
[0007]
1 and 2 are conceptual views showing a storage container 10 according to a preferred embodiment of the present invention. The storage container 10 is formed in a substantially cylindrical shape as a whole, for example, like radioactive waste. and Do radioactive material inner box 12 cylindrical storing the (material to be stored) 11, Ttei Ru such from the outer box 13 which surrounds the outer contacts the outer peripheral surface of the inner box 12. Inner box 12, like that of the prior art shown in FIG. 3, made from the inner box body lid 12b to form the upper surface is mounted et the weld 12a, a bottom portion 12d which forms a lower surface of the inner box 12 It is closed.
[0008]
On the other hand, the outer box 13 has an upper circumferential strength support plate 13 a that is an upper circumferential strength member juxtaposed adjacent to the upper surface of the top of the inner box 12, and on the lower surface formed by the bottom of the inner box 12. A lower circumferential strength support plate 13b, which is a lower circumferential strength member juxtaposed adjacent to each other , is provided, and these upper and lower circumferential strength support plates 13a and 13b include these circumferential strength support plates 13a and 13b. axial strength rods 13c are fixed spaced at equal intervals in the circumferential direction (in the embodiment 8) a plurality of extending between the vertical direction which is the axial strength member. Further, the positions of a plurality (two in the embodiment) spaced apart in the height direction in each axial strength rods 13c, cross-section are formed notch or groove 13d of the rectangle, these grooves 13d, is a side hoop strength member formed on the inner peripheral surface of the same groove (not shown) having a complementary shape with respect to these grooves 13d hoop strength ring 14 is fitted as shown .
[0009]
Therefore, in the embodiment, the thickness of the circumferential strength ring 14 (dimensions in the radial direction of the storage container) is substantially equal to the thickness of the axial strength rod 13c, and these axial strength rods 13c and the circumferential direction. The strength ring 14 is combined with each other to provide a frame structure 20 that supports axial and circumferential loads. At the upper and lower ends of each axial strength bar 13c, a step portion 15 is formed at the inner edge thereof, and receives circumferential strength support plates 13a and 13b.
[0010]
Fixing means of the above-mentioned upper and lower hoop strength support plate 13a, a fixing unit as well as the axial strength rod 13c of the axial strength rod 13c for 13b hoop strength ring 14, although not shown, also by welding, in volts Also, other means such as adhesion may be used as long as sufficient strength and durability can be secured. Further, in the embodiment, the side surface or sidewall 12c of the inner box 12, and each axial strength rod 13c of the outer box 13, is more firmly fixed to Oite welded to three welds 16 spaced in the height direction ing.
[0011]
Such a structure of the outer box, shock, Loose temporarily fixed portion by vibration or the like, even or is peeled, the upper hoop strength supporting plate 13a and the lower hoop strength support plate 13b, hoop strength ring 14 It is considered that no load is applied to the inner box 12 in which the radioactive substance 11 is stored without falling off or coming into contact . The material and dimensions of the upper and such lower hoop strength support plates 13a, 13b, axial strength bars 13c and hoop strength ring 14, it should be designed to be well tolerated in all load envisaged It goes without saying.
[0012]
The storage container 10 according to the embodiment of the present invention having the above configuration can be assembled, for example, by the following procedure. First, each circumferential strength ring 14 is fitted into a groove 13d formed in eight axial strength bars 13c, and both are welded to form a frame structure 20, and this frame structure 20 is formed with an appropriate tool (FIG. (Not shown) and placed on the lower circumferential strength support plate 13b so that the lower step portion 15 of each axial strength bar 13c contacts the peripheral edge of the lower circumferential strength support plate 13b. Then, the axial strength bars 13c are attached one after another from the side by bolts (not shown). Next, as in the case of the conventional storage container shown in FIG. 3, when the inner box 12 containing the radioactive substance 11 is prepared, the inner box 12 is suspended and lowered into the frame structure 20 described above, and the lower circumferential strength. The welded portion 16 is formed by welding the inner surface of the axial strength bar 13c placed on the support plate 13b and contacting the outer peripheral surface of the inner box 12 at three positions spaced apart in the height direction. Thereafter, when the upper circumferential strength support plate 13a is placed on the step portion 15 of each axial strength bar 13c and firmly fixed with bolts, the assembly of the storage container 10 is completed.
[0013]
In the storage container 10 of the embodiment assembled in this way, with respect to the load from above or below, this load is directly received by the upper circumferential strength support plate 13a or the lower circumferential strength support plate 13b. Is supported by the axial strength bar 13c. Further, when a load from the circumferential direction is directly received by the axial strength bar 13c, the load is supported by the upper circumferential strength support plate 13a and the lower circumferential strength via each axial strength bar 13c. It is supported by the support plate 13b or the circumferential strength ring 14. When the circumferential strength ring 14 directly receives a load from the circumferential direction, the load is supported by the circumferential strength ring 14.
[0014]
Further, in the case of a drop or seismic impact, a load based on its own weight is also generated, but the inner box 12 storing the radioactive material 11 is connected to each axial strength bar 13c by a welded portion 16 at a plurality of locations. Therefore, since the load based on the weight of the inner box 12 is supported by these welds 16, the load on the inner box 12 itself is reduced as much as possible.
[0015]
The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made. For example,
1) In the above embodiment, that secure by welding to the inner box 12 of each axis direction strength rod 13c in order to suitably transmit the load, in intimate contact with the outer peripheral surface of the inner box 12 is axial strength rod 13c If you have that you do not necessarily need to be fixed.
2) In the above embodiment, the thicknesses of the axial strength bars 13c and the circumferential strength ring 14 are substantially equal, and the frame structure 20 is formed by combining the grooves formed in the axial strength bars 13c. Only a groove may be formed and fitted.
3) In the container embodiment described above , the upper circumferential strength support plate 13a and the lower circumferential strength support plate 13b are formed of flat plates without openings, but they may have a lattice shape or a ring shape. In the case of a ring shape , the inner diameter of the ring is preferably smaller than the outer diameter of the inner box.
4) When it is not necessary to consider an excessive load from above or below, either the upper circumferential strength support plate 13a or the lower circumferential strength support plate 13b may be omitted. When the latter is omitted, the lower surface of the inner box 12 is, of course, flush with the lower end surface of each axial strength bar 13d, so that the step portion 15 below each axial strength bar 13d is unnecessary. .
5) In the above embodiment, that secure to the inner box 12 in the axial strength bars 13c the three positions, fixed point may be a number other than it, for example over substantially the entire surface of each axial strength rod 13c It may be fixed to the inner box 12.
[0016]
【The invention's effect】
As described above, according to the present invention, the reservoir consists of an inner box for storing a substance to be stored, an outer box which is disposed around the inner box, the outer box is the Upper circumferential strength member juxtaposed adjacent to the upper surface of the inner box and / or lower circumferential strength member juxtaposed adjacent to the lower surface of the inner box and upper circumferential strength member and / or lower circumferential strength member And a plurality of axial strength members arranged at equal intervals around the side surface of the inner box, and side circumferential strength members combined with grooves formed in each of these axial strength members. Since it has a frame structure , when the storage container receives a load from the circumferential direction, the upper and / or lower circumferential strength member and the side circumferential strength member of the outer box are directly or via the axial strength member. While supporting this load, the storage container is axial When receiving the load La, the axial strength member of the outer box through the upper and / or lower hoop strength member for supporting the load, it is possible to very reduce the load on the inner box. In particular, since the side circumferential direction strength member is combined with the groove formed in each axial direction strength member, it is possible to prevent the dropout and contact. Thus, In its inner box extension Ru can reduce the thickness of the entire storage container. Also, I intensity guaranteed also reduce der weld, not only reduce the material cost of the storage vessel, to simplify the welding operation on site becomes possible, it is possible to reduce the working cost.
[0017]
Further, when a plurality of axial strength members standing at equal intervals around the side surface of the inner box are fixed to the inner box, the axial strength member supports the load due to the weight of the inner box through this fixing portion. As a result, the load on the inner box can be reduced. In this case, the load is axial strength member receiving is be transmitted to the inner box, no such compromise the integrity of the inner box with locally stress occurs.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing, in a longitudinal section, one embodiment of a radioactive substance storage container according to the present invention.
FIG. 2 is a plan view of the storage container of FIG.
FIG. 3 is a longitudinal sectional view of a conventional storage container.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Storage container, 11 ... Radioactive material (material to be stored), 12 ... Inner box, 12b ... Inner box cover (upper surface), 12c ... Inner box side surface, 12d ... Inner box lower surface, 13 ... Outer box , 13a ... Upper circumferential strength support plate (circumferential strength member), 13b ... Lower circumferential strength support plate (circumferential strength member), 13c ... Axial strength bar (axial strength member), 14 ... Side circumferential strength Ring (circumferential strength member), 20... Frame structure.

Claims (2)

An inner box for storing a substance to be stored, a storage container made of an outer box which is disposed in contact with the outer peripheral surface of the inner box, the outer box is adjacent to the upper surface of the inner box The upper circumferential strength member and / or the lower circumferential strength member juxtaposed adjacent to the lower surface of the inner box and / or the upper circumferential strength member and / or the lower circumferential strength member are fixed to the inner box. The frame structure is composed of a plurality of axial strength members arranged at equal intervals around the side surface of the inner surface, and a side circumferential strength member combined with a groove formed in each of the axial strength members. storage vessel according to claim. The storage container according to claim 1, wherein each axial strength member of the frame structure is fixed to the inner box.

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