JP4479088B2 - Containment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a containment vessel, and more particularly to a reactor containment vessel that stores a reactor pressure vessel therein.
[0002]
[Prior art]
In a nuclear power plant, a containment vessel of a reinforced concrete structure (RC structure) has been conventionally used as a containment vessel for storing a reactor pressure vessel. This reinforced concrete containment is intended to shield radiation by a concrete layer. In recent years, a containment vessel having a steel-concrete structure (SC structure) in which concrete and a steel plate are combined has been studied. This steel-concrete containment vessel is configured to cast concrete between the inner steel plate and the outer steel plate, and after producing the steel plate by a factory or the like, it is only necessary to perform concrete placing work at the construction site. Good workability and quality can be ensured. In other words, in this case, the on-site construction of placing concrete remains, but it does not include the bar arrangement work that requires many skilled workers, so that the stability of the quality and the shortening of the on-site construction can be achieved.
[0003]
[Problems to be solved by the invention]
The inner steel plate and the outer steel plate in such a steel-concrete containment vessel are required to have a function of maintaining the strength of the entire containment vessel, and thus have a predetermined thickness of, for example, about 25 to 30 mm. When high-temperature and high-pressure steam flows into the containment vessel from the nuclear reactor housed inside due to an accident or the like, these steel plates (particularly, the inner steel plate at the corner portion of the containment vessel) are greatly strained due to thermal stress. And the distortion by this thermal stress may produce a crack, a fracture | rupture, etc. in a steel plate.
[0004]
The present invention has been made in view of such circumstances, and a storage container capable of ensuring safety by reducing the occurrence of cracks and breaks even during an accident while maintaining the overall strength. The purpose is to provide.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, a storage container according to the present invention includes a cylindrical first layer made of a steel plate, a cylindrical second layer made of a steel plate provided outside the first layer, and the second layer. A cylindrical third layer made of a steel plate provided on the outer side of the layer, concrete is placed between each of the layers, and the first layer includes the second layer and the third layer. It is characterized by being formed in a predetermined plate thickness thinner than the layer.
[0006]
According to the present invention, even when high-temperature water vapor flows out into the container due to an accident or the like, and the first layer is heated by being exposed to water vapor, the first layer, which is the innermost layer, Since it is made of a steel plate having a predetermined thickness that is thinner than the third layer, distortion due to thermal stress generated in the first layer is relieved by deformation (displacement) of the first layer. Therefore, generation | occurrence | production of the crack and fracture | rupture with respect to the 1st layer and the concrete casted on the outer side can be prevented. As described above, since the first layer can absorb the strain due to the thermal stress while maintaining the strength of the storage container itself by the second layer and the third layer, the safety can be improved.
[0007]
In addition, since the partition plates that divide each layer and concrete into a plurality of blocks are provided at a plurality of predetermined positions in the axial direction of these layers, the strength of the entire storage container can be further increased, and the storage container By constructing each block at the time of construction, workability can be improved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a storage container according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram for explaining a plant including a storage container, FIG. 2 is a view for explaining a side wall portion of the storage container of the present invention, and FIG. 2 (b) is a plan view seen from the first layer side.
[0009]
In FIG. 1, a nuclear power plant P having a reactor pressure vessel (reactor main body) G includes a reactor containment vessel (containment vessel) 1 that stores the reactor pressure vessel G therein. The reactor containment vessel 1 includes a side wall portion 2 formed in a cylindrical shape, a top slab T, and a diaphragm floor D, and the base of the side wall portion 2 is fixed to the base B. A shielding wall S is provided around the reactor pressure vessel G.
[0010]
As shown in FIG. 2, the side wall 2 of the reactor containment vessel 1 has a cylindrical liner (first layer) 3 made of a steel plate and an intermediate cylinder (second layer) made of a steel plate provided outside the liner. ) 4, an outer cylinder (third layer) 5 made of a steel plate provided outside the intermediate cylinder, a concrete layer 6 placed between the liner 3 and the intermediate cylinder 4, and the intermediate cylinder 4 and the outer A concrete layer 7 placed between the cylinder 5 and the cylinder 5 is provided.
[0011]
As shown in FIG. 2A, the concrete layer 6 is provided with a connecting member 8 that connects the concrete layer 6 and the intermediate cylinder 4. The connecting member 8 is made of, for example, a metal anchor, stud, rib, or the like, and the connecting member 8 prevents the intermediate cylinder 4 and the concrete layer 6 from being displaced. Similarly, the concrete layer 7 is provided with a connecting member 9 that connects the concrete layer 7 and the outer cylinder 5. The connecting member 9 is also composed of, for example, a metal anchor, stud, rib, or the like, and prevents the displacement between the outer cylinder 5 and the concrete layer 7.
[0012]
The intermediate cylinder 4 and the outer cylinder 5 have a plate thickness of about 25 to 30 mm, for example. On the other hand, the liner 3 is formed thinner than the intermediate cylinder 4 and the outer cylinder 5 and has a thickness of about 6 mm, for example. The strength of the entire reactor containment vessel 1 is maintained by the concrete layer 6, the concrete layer 7, the intermediate cylinder 4, and the outer cylinder 5. The concrete layers 6 and 7 also have a function of shielding the radiation from the reactor pressure vessel G.
[0013]
The liner 3, which is a thin steel plate, has a function of a seal member for restricting gas movement between the inside and outside of the reactor containment vessel 1. For example, the liner 3 prevents leakage of gas components to the outside of the container. The liner 3 is preset to have a thickness (rigidity) that does not cause cracks or breakage due to distortion caused by thermal stress when heated.
[0014]
The liner 3, the intermediate cylinder 4, the outer cylinder 5, and the concrete layers 6 and 7 are each divided into a plurality of blocks in the direction of the axis L by a plurality of shelf boards (partition plates) 10. The liner 3 is formed by connecting a plurality of panel members via the shelf plate 10 and the rib member 13 as shown in FIG. The shelf board 10 and the rib member 13 are comprised with the steel plate. The shelf board 10 is installed in the horizontal direction, and is connected to the liner 3, the intermediate cylinder 4, and the outer cylinder 5, respectively, and divides the concrete layers 6 and 7 into a plurality of blocks.
[0015]
In the reactor containment vessel 1 as described above, when an accident such as high-temperature high-pressure steam is ejected from the reactor pressure vessel G or piping, the liner 3 is heated by this high-temperature steam.
[0016]
Thermal stress acts on the heated liner 3 to generate thermal distortion. In particular, a large thermal distortion occurs in the corner portion C shown in FIG. At this time, since the liner 3 is thinly formed to a predetermined plate thickness, the liner 3 is small in rigidity and easily deformed (displaced). Therefore, when thermal strain occurs, the thermal strain is converted into the deformation of the liner 3 and absorbed. Therefore, concentration of stress acting on the liner 3 (side wall portion 2) due to heat can be reduced.
[0017]
In this way, the reactor containment vessel 1 has a triple structure of steel plates, and the liner 3 that is the innermost layer is formed to have a predetermined thickness that is thinner than the intermediate cylinder 4 and the outer cylinder 5, so if an Even when high-temperature water vapor flows into the reactor containment vessel 1 and the liner 3 is exposed to water vapor and heated, distortion caused by thermal stress generated in the liner 3 is absorbed by deformation (displacement) of the liner 3 itself. Is done. Therefore, generation | occurrence | production of the crack and fracture | rupture with respect to the liner 3 and the concrete layer 6 cast | placed on the outer side can be prevented. The strength of the entire reactor containment vessel 1 is maintained by the intermediate cylinder 4, the outer cylinder 5, and the concrete layers 6 and 7 having a predetermined plate thickness. Thus, the storage container 1 has high safety while maintaining strength.
[0018]
Further, shelves 10 that divide the liner 3, the intermediate cylinder 4, the outer cylinder 5, and the concrete layers 6 and 7 into a plurality of blocks are provided at a plurality of predetermined positions in the axis L direction (vertical direction) of the reactor containment vessel 1. Therefore, the strength of the entire storage container 1 can be further increased. Moreover, workability | operativity can be improved by constructing for every block at the time of construction of the containment vessel 1. Further, by dividing the side wall portion 2 into a plurality of blocks by the shelf board 10 and the rib member 13, the liner 3 is restrained from being restricted by the concrete layer 6. That is, since the force acting on the concrete layer 6 due to the thermal strain generated in the liner 3 is divided for each block, it is possible to prevent cracking and breakage of the concrete layer 6 due to the displacement of the liner 3. .
[0019]
In this embodiment, the example in which the configuration of the present invention is applied to the side wall portion 2 of the storage container 1 has been described. However, this configuration can also be applied to the top slab (roof portion) T of the storage container 1. is there.
[0020]
【The invention's effect】
According to the containment vessel of the present invention, even when high-temperature water vapor flows out into the container due to an accident or the like, and the first layer is exposed to water vapor and heated, the first layer, which is the innermost layer, Since it is composed of a steel plate having a predetermined thickness that is thinner than the second layer and the third layer, distortion due to thermal stress generated in the first layer is alleviated by deformation (displacement) of the first layer. Therefore, generation | occurrence | production of the crack and fracture | rupture with respect to the 1st layer and the concrete casted on the outer side can be prevented. As described above, since the first layer can absorb the distortion caused by the thermal stress while maintaining the strength of the storage container itself, the safety can be improved.
[0021]
Since the partition plates that divide the first to third layers and the concrete into a plurality of blocks are provided at a plurality of predetermined positions in the axial direction of these layers, it is possible to further increase the strength of the entire storage container and store it. By constructing each container at the time of construction of the container, workability can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an entire plant equipped with a storage container according to the present invention.
2A and 2B are views for explaining an embodiment of a storage container according to the present invention, in which FIG. 2A is an enlarged cross-sectional view of a main part, and FIG.
[Explanation of symbols]
1 containment vessel (reactor containment vessel)
2 Side wall 3 Liner (first layer)
4 Intermediate tube (second layer)
5 outer cylinder (third layer)
6 Concrete layer 7 Concrete layer 8 Connecting member 9 Connecting member 10 Shelf plate (partition plate)

Claims (1)

A cylindrical first layer made of a steel plate;
A cylindrical second layer made of a steel plate provided outside the first layer;
A cylindrical third layer made of a steel plate provided on the outside of the second layer ;
A first concrete layer placed between the first layer and the second layer;
A second concrete layer placed between the second layer and the third layer;
The first layer, the second layer, and the third layer are arranged so as to connect the first layer, the second layer, and the third layer at a plurality of predetermined positions in the axial direction of the first, second, and third layers. A partition plate that divides the third layer and the first and second concrete layers into a plurality of blocks,
The containment vessel, wherein the first layer is formed to have a predetermined thickness that is thinner than the second layer and the third layer , and absorbs distortion caused by thermal stress by deformation .

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