JPH0694863A - Construction method of radiation shielding wall - Google Patents

Abstract

PURPOSE:To provide an excellent workability, and to realize a partial removal of a shielding wall, by dividing the shielding wall into plural blocks, arranging steel frames to form the outer formation along the scheduled line, placing a concrete in the frames, and constructing the shielding wall in the field work. CONSTITUTION:Standards 4 of a steel pipe or the like are planted at the corners and at the center position of a shielding wall 2 to be constructed. Beams of truss structure are erected at the upper parts of the standards 4, and steel frames are arranged in order along the scheduled setting positions of the shielding wall 2, being fitted each other to prevent the generation of clearances between the end faces of the frames. In the steel frames contacting to the standards 4, the end faces of the frames are bent according to the curved surfaces of the standards 4. Then, a concrete is placed in the steel frames so as to form blocks 21, and the final shielding wall is constructed. The upper ends of the blocks 21 are fixed to the beams so as to prevent a fall of the shielding wall 2. There is almost no clearance at the connections of the blocks 21, and since the fitting end surfaces have stepped faces, a leakage of the radiant rays at the connecting surfaces can be prevented effectively. Since the shielding wall 2 is composed of plural blocks, the shielding wall 21 can be removed or attached partially, and the renewal or reforming of a radiant ray generating device is made easier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a radiation shielding wall constructed around various radiation generators.

[0002]

2. Description of the Related Art Radiation shielding measures are important in facilities that store radiation generators such as particle accelerators that generate radiation (bremsstrahlung, neutron rays, etc.). As a conventional means for shielding the radiation, there is known a method of constructing a wall around the radiation generating apparatus around the radiation generating apparatus by using a concrete-based wall integrally with the facility building (ceiling or floor). There is.

[0003]

The conventional radiation shielding technique described above has the following problems. <B> When updating or modifying the radiation generator,
The shielding wall must be removed. As a method of removing the wall, fishing or cutting can be considered, but it takes a lot of time and labor. Moreover, dust, noise, vibration, etc. are generated during construction. <B> It is necessary to reconstruct a new shielding wall after removing the wall, which is problematic in terms of construction economics.

[0004]

The present invention has been made to solve the above problems, and an object thereof is to provide the following method for constructing a radiation shielding wall. <B> A method of constructing a radiation shielding wall with excellent workability. <B> A method of constructing a radiation shielding wall that allows the shielding wall to be partially removed. <C> A method of constructing a radiation shielding wall that improves the radiation shielding effect. <D> A method of constructing a radiation shielding wall that is easy to remove.

[0005]

SUMMARY OF THE INVENTION The present invention is a method of constructing a radiation shielding wall around a radiation generator, wherein the shielding wall is divided into a plurality of blocks, and a steel frame having the outer shape of the block is shielded. It is a method for constructing a shield wall, which is characterized in that the shield walls are constructed on-site by placing concrete along each wall construction line and placing concrete in each steel frame.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

<A> Storage Facility FIG. 1 shows a plan view of a radiation generator (for example, a storage facility storing a synchrotron), and FIG. 2 shows a central sectional view thereof. The containment facility is the floor 1 on which the radiation generator is installed,
This is a Brehab type facility that is composed of a polygonal shielding wall 2 and a ceiling 3 that closes the upper opening of the shielding wall 2.

<B> Shielding Wall FIG. 3 is a perspective view in which the upper portion of the shielding wall 2 is omitted. The shielding wall 2 is composed of an assembly of a plurality of blocks 21. Each block 21 is composed of a steel frame 22 and concrete 23 cast in the steel frame 22. The steel frame 22 has both a function as a mold and a radiation shielding function, and as its material, for example, an iron plate or the like can be used. Further, if the blocks 21 are formed in a rectangular cross section and arranged side by side, there is a risk of radiation leaking from the joint. Therefore, in the present invention, each block 2
The following improvements were made to prevent radiation from leaking from the joint between the two. That is, each block 2
A pair of end faces 25, 25 sandwiched by the two side faces 24, 24
A step surface 26 was formed on the way to the end surface 25 in a direction intersecting with the end surface 25. FIG. 1 shows an example of allocation of the shielding wall and an example of combination of the end faces 25 of the blocks 21. In short, it is sufficient that the end faces 25 of the blocks 21 are formed in such a shape that no gap is formed in the joint when the end faces 25 are joined. Therefore, the end surface 25 can also be a combination of arcuate curved surfaces.

[0009]

[Operation] Next, a method of constructing the storage facility will be described.

<a> Installation of steel frame The columns 4 are erected at the corners and the central position of the shield wall 2 to be constructed. A steel pipe or the like is used for the pillar 4. Next, a beam 5 having a truss structure is installed between the upper parts of the columns. The pillar 4 standing on the floor 1 and the beam 5 erected on the pillar 4 are fixed using bolts or the like so that they can be disassembled. Then, the steel frames 22 are sequentially arranged along the planned installation position of the shielding wall 2. At this time, each steel frame 2
The two end faces 25 are fitted so that no gap is formed between them. The end face 25 of the steel frame 22 that comes into contact with the column 4 needs to be curved according to the curved surface of the column 4.

<B> Completion of Shielding Wall Next, concrete 23 is cast in each steel frame 22 to form a heavy block 21, and the final shielding wall 2 is obtained. Further, the upper end of each block 21 is fixed to the beam 5 to prevent the shielding wall 2 from falling. The joint portion of each block 21 has almost no gap over the entire length, and the end faces 25 and 2 to be fitted are
Since 5 forms a non-linear surface via the step surfaces 26, 26, it is possible to effectively prevent radiation leakage at the joint portion. In particular, the concrete pressure placed on-site causes the steel frame 22
Therefore, even if there are slight gaps before the concrete is poured, these gaps can be eliminated and the end faces 25 of the blocks 21 can be closely contacted with each other. When arranging the beam duct of the radiation generator through the inside and outside of the shielding wall 2, a large opening is provided in advance in the block 21 at the planned penetration site, and after the beam duct penetrates the opening of the block 21. To deal with this, fill the opening with concrete. A door that is slidable in the penetrating direction of the shielding wall 2 is provided in a part of the shielding wall 2 shown in FIG.

<C> Placement of Ceiling When the construction of the shielding wall 2 is completed, the ceiling 3 is placed on the upper opening of the shielding wall 2 to form a space having a sealed structure. An example of allocation of the ceiling 3 is shown in FIG. The ceiling 3 is composed of an assembly of rectangular blocks 31, and each block 31 is composed of a steel frame having a bottomed structure and the concrete to be cast on site, like the block 21. Further, in consideration of radiation leakage prevention, the ceiling 3 has a plurality of laminated structures as shown by the solid line and the broken line in FIG. 4, and the joint positions of the blocks 31 constituting the upper and lower ceilings 3 overlap on the same perpendicular line. Shift the position so that it does not become. The weight of the ceiling 3 is supported by the shield wall 2 and the columns 4 via the beams 5. In addition, the shielding wall 2 and the ceiling 3 are blocks 21 and 31.
Since the blocks 21 and 31 are jointed with silicone resin, caulking of silicone resin
If oil paint is applied to the surfaces of Nos. 1 and 31, the airtightness in the facility will be further improved.

<D> Partial Removal of Shielding Wall When part of the shielding wall 2 is to be removed due to the necessity of renewal or modification of the radiation generating device, the procedure is as follows. First, after removing the upper part of the block 21 at the planned removal position from the beam 5, it is sufficient to pull the block 21 outward or inward as shown in FIG. The block 21 is moved by pushing or pulling with a jack or the like. When the updating work is completed, the block 21 is returned to its original position and the shielding wall 2
To restore.

<E> Dismantling the whole facility When dismantling the entire facility, the ceiling 3 is lifted and removed, and then the block 21 constituting the shielding wall 2 is lifted or horizontally moved and removed. Finally, if the pillars 4 and beams 5 that are bolted together are removed, the dismantling of the entire facility is completed.

[0015]

[Other Embodiments] If the beams 5 and the ceiling 3 are directly supported by the shielding wall 2, the columns 4 can be omitted.

[0016]

Since the present invention is as described above, the following effects can be obtained. <B> Since the shielding wall is composed of a plurality of blocks, it is possible to partially attach and detach the shielding wall by removing the block at an arbitrary position. Therefore, it is possible to easily update or modify the radiation generator. In addition, the present invention can be easily removed as compared with the conventional removal technique of the shielding wall by hanging or cutting, without generating vibration or dust. <B> Since the shielding wall is composed of a laminated structure of a steel frame and concrete that does not easily transmit radiation, the radiation transmission preventing effect is improved. <C> By joining the blocks through the non-linear surface, it is possible to effectively prevent leakage of radiation at the joining portions of the blocks. <D> Placing concrete on site pressurizes the joints of each block and helps eliminate the gap. <E> Compared with the method of transporting and assembling heavy existing blocks to the site, it is possible to significantly reduce the labor and work time required to transport and install the blocks. <F> The construction period can be significantly shortened.

[Brief description of drawings]

FIG. 1 Plan view of the shielding wall

2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a perspective view of a block forming a shielding wall.

[Figure 4] Plan view of the ceiling

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirofumi Kamata 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Within Taisei Corporation (72) Inventor Masahiro Taniguchi 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo (72) Inventor Shunji Harada, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (2)

[Claims] 1. A method of constructing a radiation shield wall around a radiation generator, wherein the shield wall is divided into a plurality of blocks, and a steel frame having the outer shape of the block is arranged along a construction line of the shield wall. A method of constructing a radiation shielding wall, which comprises placing concrete in each steel frame to construct a shielding wall on site. 2. The steel frame according to claim 1, wherein the respective end faces of the steel frames to be joined to each other are formed into corresponding non-linear faces, and the end faces of the steel frame are fitted in a state without a gap. Construction method of radiation shielding wall.