Radiation shielding structure

Abstract

The present invention provides a radiation shielding structure that is easily constructed and allows for weight savings. This radiation shielding structure comprises a plurality of radiation shielding blocks 10 arranged to spread out in a planar manner and a radiation shielding cylinder 40 fitted into the radiation shielding blocks 10. The radiation shielding blocks 10 have a first surface 11 in which a first recessed part 21 is provided and a second surface 12, opposite the first surface 11, in which a second recessed part 22 is provided. Radiation shielding blocks 10 stacked on top of one another are arranged such that the first surface 11 and the second surface 12 touch, and radiation shielding blocks 10 lined up beside one another are arranged such that a third surface and a fourth surface touch. The radiation shielding cylinder 40 is fitted into the first recessed part 21 and also fitted into the second recessed part 22.

Description

radiation shielding structure

[0001] The present invention relates to a radiation shielding structure that serves as a wall structure for shielding radiation.

[0002] In recent years, international tensions have been rising, posing the risk of building destruction by missile attacks and, in some cases, nuclear attacks. While many other countries have established shelters to protect against such military attacks, Japan currently has almost no shelters or similar facilities. Meanwhile, Japan is hit by natural disasters such as earthquakes and typhoons almost every year, but evacuation sites for these disasters are limited to existing facilities, such as gymnasiums and community centers, prepared by municipalities, and there are almost no shelters specifically designed for disasters.

[0003] In light of the increasingly tense international situation, there is a growing demand in Japan as well for the installation of so-called nuclear shelters that have radiation shielding capabilities in preparation for emergencies such as war or natural disasters.

[0004] Various proposals have been made for radiation shielding structures that could be used to construct nuclear shelters.

[0005] Patent Document 1 proposes a radiation shielding body in which a plurality of radiation shielding blocks are arranged in a row and stacked one above the other in staggered positions. The radiation shielding blocks have a convex portion formed on an end face of one adjacent radiation shielding block and narrowing toward the tip, and a concave portion formed on an end face of the other adjacent radiation shielding block arranged in parallel, narrowing toward the inside of the radiation shielding block, and engaging with the convex portion.

[0006] Patent Document 2 proposes a radiation-shielding building and / or structure in which high-performance ceramic concrete is adapted as an exterior or interior wall material for a wooden building, a steel-framed building, a reinforced concrete building, or a steel-framed reinforced concrete building, and / or a structure.

[0007] JP 2017-207371 A JP 2013-195416 A

[0008] However, the inventions proposed in Patent Documents 1 and 2 have the problem that the structure of the contact points between the blocks is complicated. Furthermore, it is necessary to use multiple blocks. Furthermore, since concrete is used as the main raw material, it is difficult to reduce the weight of the blocks.

[0009] The present invention has been made in view of these problems, and aims to provide a radiation shielding structure that is easy to install and can be made lighter.

[0010] The invention for solving the above problem is a radiation shielding structure comprising a plurality of radiation shielding blocks arranged in a planar manner, and radiation shielding tubes fitted into the radiation shielding blocks, wherein the radiation shielding blocks have a first surface on which a first recess is provided, a second surface opposite the first surface on which a second recess is provided, a third surface, and a fourth surface opposite the third surface, wherein the stacked radiation shielding blocks are arranged such that the first surface and the second surface are in contact with each other, and the radiation shielding blocks arranged in a row are arranged such that the third surface and the fourth surface are in contact with each other, and the radiation shielding tubes are fitted into the first recesses and the second recesses.

[0011] According to this configuration, the radiation-shielding block has a first surface on which the first recess is provided and a second surface facing the first surface on which the second recess is provided, and the first and second surfaces of the stacked radiation-shielding blocks are in contact with each other. Furthermore, by fitting the radiation-shielding cylinder into the first recess and the second recess, it is possible to restrain the out-of-plane displacement of the stacked radiation-shielding blocks. Furthermore, a radiation-shielding structure can be constructed by arranging the radiation-shielding blocks arranged in a row with their third and fourth surfaces in contact with each other, and fitting the radiation-shielding cylinder into the second recess and then fitting it into the first recess of the stacked radiation-shielding blocks.

[0012] Preferably, the third surface is provided with a third recess and the fourth surface is provided with a protruding fitting portion, and the protruding fitting portion is fitted into a fitting hole defined by the third recess, the radiation shielding tube fitted into the first recess, and the radiation shielding tube fitted into the second recess.

[0013] According to this configuration, the third surface is provided with a third recess, the fourth surface is provided with a protruding fitting portion, and the protruding fitting portion is fitted into a fitting hole defined by the third recess, the radiation shielding cylinder fitted into the first recess, and the radiation shielding cylinder fitted into the second recess, thereby further strengthening the joint relationship between the radiation shielding blocks. Furthermore, since the joint has a complex, maze-like shape, radiation leakage from the joint is suppressed.

[0014] Preferably, the radiation shielding block is characterized by comprising a block container and an aqueous solution filled in the block container.

[0015] According to this configuration, the radiation-shielding block is composed of a block container and an aqueous solution filled in the block container, so that it can be made lighter than concrete blocks that are generally used for radiation shielding.

[0016] Preferably, the protruding fitting portion has a first protruding surface connected to the bottom surface of the first recess and a second protruding surface connected to the bottom surface of the second recess, the first protruding surface being provided with a first convex portion and the second protruding surface being provided with a second convex portion, and the radiation shielding tube being provided with a tube hole for fitting the first convex portion and the second convex portion.

[0017] According to this configuration, the protruding fitting portion has a first protruding surface connected to the bottom surface of the first recess and a second protruding surface connected to the bottom surface of the second recess, the first protruding portion is provided on the first protruding surface, and the second protruding portion is provided on the second protruding surface, and the first protruding portion and the second protruding portion are fitted into a tube hole provided in the radiation shielding tube, so that the radiation shielding block and the radiation shielding tube can be structurally integrated. Also, the relative positional relationship between the radiation shielding block and the radiation shielding tube can be uniquely determined.

[0018] Preferably, the first convex portion is provided with a first cap for filling / discharging the aqueous solution, and the second convex portion is provided with a second cap for filling / discharging the aqueous solution.

[0019] According to this configuration, the first convex portion and the second convex portion are provided with a first cap and a second cap for filling / discharging the aqueous solution, so that the aqueous solution filled in the block container can be easily replaced.

[0020] Preferably, the block container has a fifth surface and a sixth surface, and the fifth surface and / or the sixth surface is characterized in that a pressure absorbing portion is provided for absorbing changes in the internal pressure of the radiation shielding block.

[0021] According to this configuration, the block container has a fifth surface and a sixth surface, and the fifth surface and / or the sixth surface is provided with a pressure absorbing portion for absorbing changes in the internal pressure of the radiation shielding block, so that pressure fluctuations inside the block container due to expansion and contraction of the aqueous solution can be suppressed, thereby improving the pressure resistance of the block container.

[0022] Preferably, the pressure absorbing portion includes a concave-convex portion extending in a direction perpendicular to the direction in which the radiation shielding cylinder extends.

[0023] According to this configuration, the pressure absorbing part includes an uneven portion having an uneven shape extending in a direction perpendicular to the extension direction of the radiation shielding cylinder, so that by forming unevenness in the block container, it is possible to easily improve the pressure resistance of the block container. Furthermore, by forming the uneven shape, it is possible to increase the out-of-plane rigidity of the surface on which the uneven shape is formed, thereby suppressing deformation such as sagging of the surface.

[0024] The radiation shielding cylinder is characterized by comprising a rectangular cylindrical container and an aqueous solution filled in the rectangular cylindrical container.

[0025] According to this configuration, the radiation-shielding cylinder is composed of a rectangular cylindrical container and an aqueous solution filled in the rectangular cylindrical container, so it can be made lighter than the concrete blocks that are generally used for radiation shielding.

[0026] 1. A front view of the radiation shielding structure, with the uneven portion omitted. A cross-sectional view taken along line A-A in FIG. 1. With the uneven portion omitted. (a) is a cross-sectional view taken along line B-B in FIG. 1. (b) is a cross-sectional view taken along line C-C in FIG. 1. With the uneven portion omitted in both (a) and (b). (a) is a front view of a radiation shielding block. (b) is a plan view of the same. (a) is a plan view of a radiation shielding cylinder. (b) is a cross-sectional view taken along line A-A in (a). With the uneven portion omitted in part A'-A' in FIG.

[0027] Hereinafter, an embodiment of the radiation shielding structure of the present invention will be described in detail with reference to FIGS.

[0028] 1 to 3, the radiation shielding structure 1 (hereinafter referred to as the shielding structure 1) has a plurality of radiation shielding blocks 10 (hereinafter referred to as the shielding blocks 10) arranged in a planar manner, with the outer edges held by a frame body 60. The frame body 60 is made up of horizontal frame members 61, 62 and vertical frame members 63, 64. The vertical frame members 63, 64 and the horizontal frame members 61, 62 are assembled on all four sides to hold the outer edges of the shielding blocks 10 arranged in a grid pattern.

[0029] The shielding blocks 10 stacked vertically have their first surfaces 11 and second surfaces 12 in contact with each other (see Figure 2), and the shielding blocks 10 arranged in a horizontal row have their third surfaces 13 and fourth surfaces 14 in contact with each other (see Figure 3), and these multiple shielding blocks 10 are arranged in a grid pattern.

[0030] In this embodiment, the radiation shielding structure is assumed to be installed outside the building, but this is not limiting and the structure may be installed inside the building, for example. In this case, the horizontal frame members may be joined to the ceiling, and the vertical frame members may be joined to the wall surface. Furthermore, a plurality of shielding structures may be combined to create a space inside the building that can be shielded from radiation.

[0031] 2, the horizontal frame member 61 has a first fitting protrusion 65 provided inside a groove-shaped structural member. The horizontal frame member 61 is also fixed to the foundation 110 via a base plate BP. By fixing the base plate BP to the foundation 110 with anchor bolts AB, the shielding structure 1 can be maintained in a stable upright state.

[0032] The first fitting convex portion 65 is fitted into the first concave portion 21 provided on the first surface 11 of the shielding block 10 located at the lowest level. As a result, the shielding blocks 10 located at the lowest level are lined up in an orderly fashion in a row in the direction in which the horizontal frame member 61 extends, and displacement in the out-of-plane direction is restricted.

[0033] The horizontal frame member 62 has a structure in which a second fitting protrusion 66 is provided inside the groove-shaped member, and is in surface contact with the second surface 12 of the shielding block 10 located in the uppermost tier. The second fitting protrusion 66 is fitted into a second recess 22 provided in the second surface 12 of the shielding block 10 located in the uppermost tier. As a result, the shielding blocks 10 located in the uppermost tier are lined up in an orderly row in the direction in which the horizontal frame member 62 extends, and movement in an out-of-plane direction is restricted.

[0034] 3, the vertical frame member 63 has a structure in which a third fitting protrusion 67 is provided inside the channel-shaped member. The third fitting protrusion 67 is fitted into a third recess 23 provided on the third surface 13 of the shielding block 10.

[0035] The vertical frame member 64 has a structure in which a fourth fitting recess 68 is provided inside the channel-shaped member. The fourth fitting recess 68 fits into the protruding fitting portion 24 provided on the fourth surface 14 of the shielding block 10.

[0036] 2 , when the first surfaces 11 and second surfaces 12 of the stacked shielding blocks 10 are in contact with each other, the first recesses 21 and second recesses 22 cooperate to define a cavity 18. A radiation shielding cylinder 40 is fitted into this cavity 18. The radiation shielding cylinder 40 passes through the cavity 18, with one end connected to a vertical frame member 63 and the other end connected to a vertical frame member 64.

[0037] As shown in Fig. 3 , when the third surface 13 and the fourth surface 14 are in contact with each other, the tip of the protruding fitting portion 24 provided on the fourth surface 14 comes into contact with the bottom of the third recess 23 provided on the third surface 13. The protruding fitting portion 24 has a shape that allows it to be inserted into the third recess 23, and as shown in Fig. 4(a) , has a first protruding surface 31 that is provided in the same plane as the bottom surface 21a of the first recess 21, and a second protruding surface 32 that is provided in the same plane as the bottom surface 22a of the second recess 22. Therefore, the first protruding surface 31 comes into surface contact with the radiation shielding tube 40 that is fitted into the first recess 21, and the second protruding surface 32 comes into surface contact with the radiation shielding tube 40 (hereinafter referred to as the shielding tube 40) that is fitted into the second recess 22. That is, the protruding fitting portion 24 is fitted into a fitting hole 45 defined by the third recess 23, the shielding tube 40 fitted into the first recess 21, and the shielding tube 40 fitted into the second recess 22.

[0038] The shielding block 10 is composed of a block container 50 and an aqueous solution W1 filled in the block container 50 (see FIG. 2). The block container 50 is a roughly rectangular parallelepiped container composed of a first surface 11, a second surface 12, a third surface 13, a fourth surface 14, a fifth surface 15, and a sixth surface 16 (see FIGS. 4(a) and 4(b)). The material of the block container 50 is preferably a material that has excellent heat resistance and is difficult to deform. A specific example is polycarbonate. Furthermore, by using a transparent or translucent material for the block container 50, it can be made to have excellent interior design appeal.

[0039] The aqueous solution W1 filled in the block container 50 is preferably one that changes little over time and has excellent shielding properties against radiation, particularly neutrons. Specific examples include boric acid water.

[0040] As shown in FIG. 5( b), the shielding cylinder 40 is composed of a rectangular cylindrical container 55 and an aqueous solution W2 filled in the rectangular cylindrical container 55. The material of the rectangular cylindrical container 55 may be different from that of the block container 50, but it is preferably a material that is difficult to deform. It may be made of a plastic material like the block container 50, but it may also be made of a metal material. Furthermore, like the aqueous solution W1 filled in the block container 50, the aqueous solution W2 filled in the rectangular cylindrical container 55 is preferably one that changes little over time and has excellent shielding properties against radiation, particularly neutrons. Specifically, boric acid water or the like can be used.

[0041] 4( a) and 4(b), a first stopper 35 is provided on the first protruding surface 31, and a second stopper 36 is provided on the second protruding surface 32. The first stopper 35 and the second stopper 36 are stoppers for filling the block container 50 with the aqueous solution W1 or discharging the aqueous solution W1 filled in the block container 50. As shown in FIG. 6, the first stopper 35 is provided with a thread groove 35a, and the second stopper 36 is provided with a thread groove 36a. Furthermore, a first cap 37 and a second cap 38 for opening and closing the first stopper 35 and the second stopper 36 are provided with thread grooves 37a and 38a corresponding to the thread grooves 35a and 36a. The first stopper 35 and the second stopper 36 are closed or opened by screwing or unscrewing the thread grooves 35a and 37a, and the thread grooves 36a and 38a.

[0042] The first protruding surface 31 is a surface provided on the protruding fitting portion 24, extends horizontally from an end of the bottom surface 21a of the first recess 21, and is located on the same plane as the bottom surface 21a of the first recess 21. The second protruding surface 32 is a surface provided on the protruding fitting portion 24, extends horizontally from an end of the bottom surface 22a of the second recess 22, and is located on the same plane as the bottom surface 22a of the second recess 22. The first plug 35 is provided to protrude vertically from the first protruding surface 31. The second plug 26 is provided to protrude vertically from the second protruding surface 32.

[0043] The first convex portion 33 is made up of a first plug 35 and a first cap 37 , and the second convex portion 34 is made up of a second plug 36 and a second cap 38 .

[0044] The fifth surface 15 and the sixth surface 16 are provided with uneven portions 25. The uneven portions 25 are uneven portions extending in a direction perpendicular to the first surface 11 or the second surface 12, and are provided to absorb changes in the internal pressure of the block container 50. Specifically, when the internal pressure in the block container 50 increases, the protruding portions 25a deform in a protruding direction to absorb the increase in pressure. Furthermore, when the internal pressure in the block container 50 decreases, the depressed portions 25b deform in a depressed direction to absorb the decrease in pressure. Furthermore, the provision of the uneven shapes can prevent the fifth surface 15 and the sixth surface 16 from sagging out of the plane.

[0045] 5(a) and (b), the rectangular tube container 55 of the shielding tube 40 has cylindrical holes 56 at predetermined intervals corresponding to the first cap 37 and the second cap 38. By fitting the first cap 37 and the second cap 38 into the cylindrical holes 56 provided in the rectangular tube container 55 (see FIG. 6), the relative positions of the rectangular tube container 55 and the block container 50 can be determined uniquely. Furthermore, the rectangular tube container 55 and the block container 50 can be structurally integrated.

[0046] A method for constructing the radiation shielding structure of this embodiment will be described.

[0047] The horizontal frame member 61 is fixed to the base plate BP. The vertical frame members 63 and 64 are installed and connected to both ends of the horizontal frame member 61.

[0048] The shielding blocks 10 are dropped into the grooves 61a of the horizontal frame member 61 and arranged in a row, so as to be in surface contact with the horizontal frame member 61. At this time, the interior of the horizontal frame member 61 is in surface contact with the first surface 11 and also with parts of the fifth surface 15 and the sixth surface 16. Furthermore, the mating protrusions 65 provided inside the horizontal frame member 61 are fitted into the first recesses 21, and the first caps 37 are fitted into horizontal frame holes 61b (not shown) provided in the mating protrusions 65 of the horizontal frame member 61. Of the shielding blocks 10 arranged in a row, the shielding block 10 in contact with the vertical frame member 63 has its third recess 23 fitted into the third mating protrusion 67 provided on the vertical frame member 63. Furthermore, the shielding block 10 in contact with the vertical frame member 64 has its protruding mating portion 24 fitted into its fourth mating recess 68.

[0049] After the lowest shielding blocks 10 have been lined up in a row, the shielding tube 40 is dropped and fitted into the second recess 22 provided in the lowest shielding block 10. At this time, one end of the shielding tube 40 contacts the third mating convex portion 67 provided in the vertical frame member 63, and the other end is fitted into the fourth mating recess 68 provided in the vertical frame member 64. In addition, the second cap 38 of the shielding block 10 is fitted into the tube hole 56.

[0050] Thereafter, further shielding blocks 10 are dropped down and stacked on top of the lowest shielding block 10, and arranged in a row. The second surface 12 of the lowest shielding block 10 and the first surface 11 of the stacked shielding blocks 10 come into surface contact, and the shielding tubes 40 are fitted into the first recesses 21 of the stacked shielding blocks 10. The first caps 37 of the stacked shielding blocks 10 are fitted into the tube holes 56 of the shielding tubes 40. Furthermore, of the stacked shielding blocks 10, the third recesses 23 provided on the shielding blocks 10 that contact the vertical frame member 63 fit into the third mating protrusions 67 provided on the vertical frame member 63. The protruding fitting portions 24 provided on the shielding blocks 10 that contact the vertical frame member 64 fit into the fourth mating recesses 68 provided on the vertical frame member 64.

[0051] The above-described procedure is repeated to stack the shielding blocks 10 up to the top tier. Then, the horizontal frame member 62 is dropped down so that it comes into surface contact with the top-tier shielding block 10 and is connected to the vertical frame members 63 and 64. At this time, the second fitting convex portion 66 provided on the horizontal frame member 62 is fitted into the second concave portion 22 provided on the top-tier shielding block 10, and the second cap 38 of the top-tier shielding block 10 is fitted into the horizontal frame hole 62b (not shown) provided on the second fitting convex portion 66.

[0052] As described above, the construction of the radiation shielding structure can be completed almost entirely through the process of alternately stacking the shielding blocks 10 and the shielding cylinders 40. In other words, processes such as laying joints are not required, and the construction can be extremely simple.

[0053] This embodiment is merely an example, and modifications can be made without departing from the technical spirit of the present invention. For example, the uneven portion may be provided on only one of the fifth and sixth surfaces. The material filled in the block container and the shielding tube does not necessarily have to be an aqueous solution. For example, it may be a granular material with radiation shielding properties.

[0054] The shielding structure according to the present invention can be installed both inside and outside a building. Furthermore, by using a transparent or translucent block container, a radiation-shielding wall with a high interior design appeal can be constructed, which has great industrial applicability.

[0055] DESCRIPTION OF SYMBOLS 1: Shielding structure 10: Shielding block 11: First surface 12: Second surface 13: Third surface 14: Fourth surface 15: Fifth surface 16: Sixth surface 21: First recess 21a, 22a: Bottom surface 22: Second recess 23: Third recess 24: Protruding fitting portion 25: Concave and recessed portion 31: First protruding surface 32: Second protruding surface 33: First protruding portion 34: Second protruding portion 37: First cap 38: Second cap 40: Shielding tube 45: Fitting hole 50: Block container 55: Square tube container 56: Cylinder hole W1, W2: Aqueous solution

Claims

1. A radiation shielding device comprising: a plurality of radiation shielding blocks arranged in a planar manner; and a radiation shielding tube fitted into the radiation shielding blocks, wherein the radiation shielding blocks have a first surface on which a first recess is provided, a second surface opposite the first surface on which a second recess is provided, a third surface, and a fourth surface opposite the third surface, wherein the stacked radiation shielding blocks are arranged such that the first surface and the second surface are in contact with each other and the radiation shielding blocks arranged in a row are arranged such that the third surface and the fourth surface are in contact with each other, wherein the radiation shielding blocks are comprised of a block container and an aqueous solution filled in the block container, wherein the radiation shielding tube is fitted into the first recess and is also fitted into the second recess, wherein the third surface is provided with a third recess and the fourth surface is provided with a protruding fitting portion, and wherein the protruding fitting portion is fitted into a fitting hole defined by the third recess, the radiation shielding tube fitted into the first recess, and the radiation shielding tube fitted into the second recess, a first protruding surface connected to a bottom surface of the first recess and a second protruding surface connected to a bottom surface of the second recess, the first protruding surface having a first convex portion and the second protruding surface having a second convex portion; and the radiation shielding tube having a tube hole for fitting the first convex portion and the second convex portion.

2. The radiation shielding structure described in claim 1, characterized in that the first convex portion is provided with a first cap for filling / discharging the aqueous solution, and the second convex portion is provided with a second cap for filling / discharging the aqueous solution.

3. The radiation shielding structure described in claim 1, characterized in that the block container has a fifth surface and a sixth surface, and the fifth surface and / or the sixth surface are provided with a pressure absorbing portion for absorbing changes in the internal pressure of the radiation shielding block.

4. The radiation shielding structure according to claim 3, characterized in that the pressure absorbing portion includes an unevenly shaped portion extending in a direction perpendicular to the direction in which the radiation shielding tube extends.

5. A radiation shielding structure comprising: a plurality of radiation shielding blocks arranged in a planar manner; and a radiation shielding tube fitted into the radiation shielding blocks, wherein the radiation shielding blocks have a first surface on which a first recess is provided, a second surface opposite the first surface on which a second recess is provided, a third surface, and a fourth surface opposite the third surface, wherein the stacked radiation shielding blocks are arranged such that the first surface and the second surface are in contact with each other and the radiation shielding blocks arranged in a row are arranged such that the third surface and the fourth surface are in contact with each other, wherein the radiation shielding tube is fitted into both the first recess and the second recess, and wherein the radiation shielding tube is composed of a rectangular cylindrical container and an aqueous solution filled in the rectangular cylindrical container.

Images