JPS6323355Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to pools where water leakage is strictly regulated, such as nuclear power pools.

Swimming pool type reactor pool, spent nuclear fuel storage pool, radioisotope storage pool,
In nuclear-powered pools such as radioactive waste storage pools, there is a risk that radioactive substances may be mixed in the water, so leakage of the water to the outside is strictly regulated. Therefore, these pools usually have a diameter of 3 mm to 10 mm.
A mm thick stainless steel section or aluminum plate is lined over the concrete structure.

Figure 1 shows its structure. FIG. 1 is a partially enlarged view of the bottom of the pool, where X is the pool water and Y is the concrete frame.

Anchor 1 is attached to this concrete frame Y during pouring.
A base material 2 is attached to the anchor 1, and a concrete wall filled with a finishing material 3 such as mortar cement is finished so that the base material 2 is exposed. A steel or aluminum lining plate 4 is laid on top of this, and the base material 2
Welded on top. The welded part 5 is inspected by a liquid penetration test (hereinafter referred to as PT) and a vacuum bubble air tightness test (hereinafter referred to as soap bubble test) performed by placing a vacuum box over the welded part. (hereinafter referred to as RT) was not possible. It is difficult to completely detect defects in welds using PT and soap bubble tests, and as a result, water leaks often occur in pools with this type of structure.

In order to improve this drawback, there is a structure shown in FIG. 2, for example.

In this structure, a lining plate 10 whose peripheral portions have been appropriately bent is welded at a welded part 11 on a base plate 2 to form a groove 12, and a strip 13 is attached thereon to make contact with the lining plate 10. The welded parts 14 and 15 are formed by welding the parts, thereby forming the groove 12. If there is a defect in the welds 14, 15 and water leaks, the structure is such that the leaked water is collected through the groove 12 and does not leak to the outside. Further, in Japanese Patent Publication No. 50-36423, the groove 12 is made into a sealed structure, and this space is pressurized from the water head of the pool, so that water leakage does not occur in principle.

However, in the case of this structure, the concrete frame Y,
Since the finishing material 3 is placed first and the lining plate 10 is attached on top of it, the finishing material 3 and the lining plate 10 are not joined except for the welded parts, and the lining plate 10 is thin so it cannot be welded. The lining plate 10 was distorted and curved, and the lining plate 10 rose above the three surfaces of the finishing material and became uneven.

On the other hand, if the pool size is relatively small,
As shown in Special Publication No. 51-385, a prefabricated construction method is used in which blocks are manufactured as one piece or partial blocks at a manufacturing factory, assembled and installed on site, and then concrete or mortar is poured around the outside of the block. In this case, the welding is done before concrete or mortar is placed, so RT is possible and the integrity of the weld is guaranteed. However, during concrete pouring, external pressure is applied to the thin lining plate, creating a large residual stress, particularly in the center of the plate away from the welded area. If it becomes necessary to weld supports etc. to this part after the pool is completed, there are drawbacks such as the risk of cracks forming in that part and water leakage.

This invention was made in order to improve the drawbacks of the prior art described above, and uses a clad steel plate consisting of a thick carbon steel part and a thin stainless steel part as the lining plate, and The basic feature is that the lining faces the inside of the pool.

Embodiments of the present invention will be described below based on the drawings.

Figure 3 is a partial sectional view of the bottom of the pool.
Components that are the same as in Figure 1 are given the same numbers.
In the figure, 20 is a clad steel plate laid on the finishing material 3 and welded onto the base material 2. In the figure, 23 is a stainless steel welded part, and 24 is a carbon steel welded part.

This clad steel plate is made by adhering a thin stainless steel plate to a thick carbon steel plate by rolling or explosion bonding.
A possible option is one crimped onto mm-thick SM41B.
Weldability is improved by using this SM material.

In this embodiment, 21 is a stainless steel part made of SUS304, and 22 is a carbon steel part of SM41B.

Fig. 4 shows another embodiment in which construction is carried out using the above-mentioned prefabricated construction method, and 30 is a concrete pit formed in the concrete frame Y, in which a lining frame 31 pre-assembled in a factory etc. is inserted. is set up. The lining frame and concrete bits 30 are connected by anchor bolts 32, and concrete is placed in the gaps between them. Clad steel plates 33a and 33b are attached to the lining frame 31 as linings. This clad steel plate is the same as that used in the embodiment shown in FIG. 4 above.

When a pool with the structure described above is constructed using the on-site board cladding method, the clad steel plates are thick, so the plates will not bend or bend due to welding due to the thick thickness. Furthermore, since the weld penetration depth (corresponding to the plate thickness) is deep, there is an advantage that welding defects that penetrate the plate are less likely to occur.

In addition, since we use a clad steel plate whose base material is carbon steel, even if there are minute defects in welds, water leakage will cause the carbon steel to rust, and this rust will cause clogging, naturally preventing water leakage. Benefits can be obtained.

On the other hand, if construction is carried out using the prefabricated construction method, which is manufactured as an integral or partial block at a manufacturing factory,
In addition to the advantages of this construction method, the cladding steel plate itself becomes a strength member due to its thick plate thickness, and the need for reinforcement can be significantly reduced compared to the case of thin lining plates, and the amount of deformation due to concrete pouring is small, resulting in less residual stress. Therefore, even if a support or the like is welded to the center portion of the plate, the plate will not crack and water will not leak. If clad steel plates are used, the prefabricated construction method is recommended because the rigidity increases, making transportation and installation easier.

As explained above, in the pool of the present invention, welding defects and cracks are less likely to occur, and even if a welding defect occurs, the defective part is covered by the rust of the carbon steel, which is the base material of the clad steel plate. , water leakage is properly prevented. It also has the effect of improving workability and making it easier to transport materials.

[Brief explanation of the drawing]

Figures 1 and 2 are partial sectional views showing the structure of a conventional pool, Figure 3 is a partial sectional view showing one embodiment of the present invention, and Figure 4 is a partial sectional view showing another embodiment. . In the figure, 20 is a clad steel plate, 21 is a stainless steel part, 22 is a carbon steel part, 23 is a stainless steel weld part, 24 is a carbon steel weld part, 30 is a concrete bit, 31 is a lining frame, 32 is an anchor bolt, 33a and 33b each indicate a clad steel plate.

Claims (1)

[Scope of utility model registration request] A pool in which leakage of water is strictly regulated, characterized by lining a clad steel plate consisting of a thick carbon steel part and a thin stainless steel part with the stainless steel part facing the inside of the pool.