Construction method and bottom structure of a nuclear reactor building

Abstract

This invention provides a method for constructing reactor buildings that can shorten construction time. [Solution] A method for constructing a reactor building 1, which includes an outer frame 3 that houses a reactor containment vessel 2, comprising an assembly step in which the container mat portion 11, which is the bottom of the containment vessel 2, the container wall portion 12a of the containment vessel 2, the frame mat portion 31, which is the bottom of the outer frame 3, and the frame wall portion 32a of the frame 3 are integrated in an assembly area, and an installation step in which the bottom structure 7 integrated in the assembly area is transported to the construction location and installed. The containment vessel 2 and the frame 3 are constructed of a steel plate concrete structure, and in the installation step, the bottom structure 7 is transported and installed before concrete pouring, after which concrete pouring is performed.

Description

Technical Field

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[0001] The present invention relates to a method for constructing a reactor building and a bottom structure.

Background Art

[0002] As a reactor building for housing a reactor containment vessel, a steel plate concrete structure is known (for example, see Patent Document 1). When constructing such a reactor building, first, as shown in FIG. 4, the bottom of the containment vessel (containment vessel mat) 101 is laid at the construction position of the reactor building (see FIG. 4A), and the wall 102 of the containment vessel is installed on the containment vessel mat 101 (see FIG. 4B). Then, the bottom of the building (frame mat) 103 is laid on the outer peripheral portion of the containment vessel mat 101 (see FIG. 4C), and the wall of the building (frame wall) 104 is installed on the frame mat 103 (see FIG. 4D). The joining of each member is performed by welding the steel plates serving as the outer shell. After the steel plates are joined, concrete is placed inside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional method for constructing a reactor building, since the containment vessel mat 101, the wall 102 of the containment vessel, the frame mat 103, and the frame wall 104 are sequentially constructed at the construction site, there is a problem that a lot of labor and time are required for construction. In particular, since the containment vessel mat 101 and the wall 102 of the containment vessel require airtightness, a welding inspection of the joint portion is necessary, but the welding inspection requires more time.

[0005] An object of the present invention is to provide a method for constructing a reactor building and a bottom structure that solve the above-described problems and can shorten the construction time. [Means for solving the problem]

[0006] To solve the aforementioned problems, the present invention provides a method for constructing a reactor building comprising an outer frame that houses a containment vessel of a nuclear reactor, characterized in that it comprises an assembly step of integrating a container mat portion which is the bottom of the containment vessel, a container wall portion of the containment vessel, a frame mat portion which is the bottom of the outer frame, and a frame wall portion of the frame in an assembly area, and an installation step of transporting the bottom structure integrated in the assembly area to the construction location and installing it. [Effects of the Invention]

[0007] According to the reactor building construction method and bottom structure of the present invention, construction time can be shortened. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a schematic cross-sectional view showing a bottom structure constructed by a reactor building construction method according to an embodiment of the present invention. [Figure 1B] This is a schematic cross-sectional view showing the installation process of a reactor building construction method according to an embodiment of the present invention. [Figure 1C] This is a schematic cross-sectional view showing the bottom structure after concrete pouring. [Figure 2] This is a schematic cross-sectional view showing a reactor building constructed using the reactor building construction method according to an embodiment of the present invention. [Figure 3] This is a schematic perspective view showing the bottom structure constructed using the reactor building construction method of the present invention. [Figure 4A] This is a schematic cross-sectional view showing the process of laying the bottom of the containment vessel in a conventional reactor building construction method. [Figure 4B] This is a schematic cross-sectional view showing the process of installing the containment vessel walls in a conventional reactor building construction method. [Figure 4C] This is a schematic cross-sectional view showing the process of laying the base of a conventional reactor building. [Figure 4D]This is a schematic cross-sectional view showing the process of installing the building walls in a conventional reactor building construction method. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings as appropriate. Figure 1A is a schematic cross-section showing the bottom structure constructed by the reactor building construction method, Figure 1B is a schematic cross-sectional view showing the installation process of the reactor building construction method, Figure 1C is a schematic cross-sectional view showing the bottom structure after concrete pouring, Figure 2 is a schematic cross-sectional view showing the reactor building, and Figure 3 is a schematic perspective view showing the bottom structure.

[0010] First, the structure of the reactor building 1 will be described. As shown in Figure 2, the reactor building 1 in this embodiment is a light water reactor type nuclear facility, with the reactor containment vessel 2 located in the center, and the main structure 3 formed on the outside of the reactor containment vessel 2. The reactor containment vessel 2 and the main structure 3 are constructed of a steel plate concrete structure, formed by pouring concrete inside the steel plates that form the outer shell. High-flow concrete is used for the concrete. Studs are attached to the inside of the steel plates to anchor the concrete.

[0011] The reactor containment vessel 2 is a vessel that houses the reactor pressure vessel 4. In addition to the reactor pressure vessel 4, the reactor containment vessel 2 also houses the main steam system piping, recirculation system, and related equipment (not shown). Inside the reactor containment vessel 2, a drywell 5 is formed around the reactor pressure vessel 4. The reactor containment vessel 2 acts as a barrier (containment function) against the release of radioactive materials into the environment in the event of fuel damage in the reactor due to a loss of coolant accident or the like, thereby ensuring the safety of the general public around the power plant and the power plant employees, and is equipped with high airtightness.

[0012] The reactor containment vessel 2 comprises a bottom section 11, a wall section 12, and a ceiling section 13. As shown in Figures 1 and 3, the bottom section 11 is formed in a circular mat shape in plan view and corresponds to the "container mat section". The bottom section 11 is divided by upper and lower steel plates 14, 14 and side steel plates 15 that cover the periphery, and concrete 16 is poured inside. Of the outer periphery of the bottom section 11, which is the container mat section, a reinforcing steel plate 17 is installed below the wall section 12, spanning between the upper and lower steel plates 14, 14.

[0013] The wall section 12 has a cylindrical shape and rises from the outer edge of the bottom section 11. The wall section 12 is divided by an outer steel plate 18 and an inner steel plate 19, and concrete 16 is poured inside. The lower end of the wall section 12 that rises from the bottom section 11 (container mat section) is called the "container wall section 12a". The rise height of the container wall section 12a should be about 600 mm. At the upper end of the container wall section 12a, a bracket 20 is installed, connecting the outer steel plate 18 and the inner steel plate 19, and is stretched between the steel plates 18 and 19. The ceiling section 13 seals the upper end of the wall section 12, and in this embodiment, it has a stepped shape with a raised central section (see Figure 2).

[0014] The structural frame 3 is a structure that constitutes the outer building housing the reactor containment vessel 2, and comprises a structural frame bottom 31, a structural frame outer wall 32, and a structural frame roof 33. The structural frame bottom 31 is the lowest floor portion of the building and is formed on the same plane as the bottom 11. The structural frame bottom 31 is formed on the outer periphery of the bottom 11, has an annular shape, and corresponds to the "structural frame mat portion". The structural frame bottom 31 is partitioned by upper and lower steel plates 34, 34, side steel plates 35 covering the periphery, and side steel plates 15 of the bottom 11, and concrete 36 is poured inside. Of the outer periphery of the structural frame bottom 31, which is the structural frame mat portion, a reinforcing steel plate 37 is installed between the upper and lower steel plates 34, 34 below the structural frame wall 32. Furthermore, the outer shape of the bottom portion 31 of the structure is not limited to a circle, but may be rectangular, for example, depending on the shape of the reactor building 1.

[0015] The outer wall part 32 of the body has a cylindrical shape and rises from the outer peripheral edge of the bottom part 31 of the body. The outer wall part 32 of the body is partitioned by a steel plate 38 on the outer peripheral side and a steel plate 39 on the inner peripheral side, and concrete 36 is placed inside. The lower end part of the outer wall part 32 of the body that rises from the bottom part 31 (body mat part) of the body is referred to as the "body wall part 32a". At the upper end part of the body wall part 32a, a bracket 40 that connects the steel plate 38 on the outer peripheral side and the steel plate 39 on the inner peripheral side is installed across between the steel plates 38 and 39. Note that the shape of the outer wall part 32 of the body is not limited to a cylindrical shape, and may be, for example, a rectangular cylindrical shape according to the shape of the reactor building 1. The roof part 33 of the body closes the upper end part of the outer wall part 32 of the body, and in this embodiment, it has a dome shape (see FIG. 2).

[0016] In the reactor building 1 according to this embodiment, the bottom part 11 (container mat part) of the reactor containment vessel 2, the container wall part 12a (lower end part of the wall part 12), the bottom part 31 (body mat part) of the body 3, and the body wall part 32a (lower end part of the outer wall part 32 of the body) are integrated to form the bottom structure 7. The bottom structure 7 is pre-assembled in an assembly area separate from the construction position of the reactor building 1. For the bottom structure 7, an outer shell made of steel plates is first assembled, and after being installed at the construction position, concrete 16 is placed inside the outer shell.

[0017] Next, the construction method of the reactor building 1 according to this embodiment will be described. The construction method of the reactor building 1 includes an assembly process of assembling the bottom structure 7, an installation process of installing the bottom structure 7, a construction process of the reactor containment vessel 2, and a construction process of the body 3.

[0018] The assembly process is a process of assembling and integrating the bottom 11 and the container wall portion 12a of the reactor containment vessel 2, and the bottom 31 and the body wall portion 32a (the lower end portion of the outer body wall 32) of the building structure 3 as shown in FIG. 1A. When assembling the bottom structure 7, first, the upper and lower steel plates 14, 14, the side steel plate 15, and the reinforcing steel plate 17 of the bottom 11 are assembled by welding to form the outer shell of the bottom 11. Then, on the upper part of the bottom 11, the outer peripheral side steel plate 18, the inner peripheral side steel plate 19, and the bracket 20 of the container wall portion 12a are assembled by welding to form the outer shell of the container wall portion 12a. After that, on the outer peripheral portion of the bottom 11, the upper and lower steel plates 34, 34, the side steel plate 35, and the reinforcing steel plate 37 of the body bottom 31 are assembled by welding to form the outer shell of the body bottom 31. And finally, on the upper part of the body bottom 31, the outer peripheral side steel plate 38, the inner peripheral side steel plate 39, and the bracket 40 of the body wall portion 32a are assembled by welding to form the outer shell of the body wall portion 32a. In the assembly process, welding inspection of each part is carried out. In the assembly process, the time of the assembly work and the inspection work is calculated backward, and the process is arranged so that the bottom structure 7 is completed before the timing of the conveyance of the bottom structure 7. That is, the assembly of the bottom structure 7 is carried out in parallel with the construction of the foundation 8 of the reactor building 1 and the like. Note that in the assembly process, the placing of the concrete 16 is not carried out.

[0019] The installation process is a process of conveying the bottom structure 7 to the construction position and installing it as shown in FIG. 1B. In the installation process, the bottom structure 7 before the placing of the concrete 16 is conveyed, and after being installed, the placing of the concrete 16 is carried out (see FIG. 1C). The conveyance of the bottom structure 7 is lifted using a hoisting device such as a crane and placed on the construction position (on the constructed foundation 8). Note that the reference numeral "50" in FIG. 1B is the wire of a crane not shown. After the installation of the bottom structure 7, the concrete 16 is placed and filled into the steel plate of the bottom structure 7.

[0020] The construction process of the reactor containment vessel 2 and the construction process of the building structure 3 are carried out appropriately in parallel after the construction of the bottom structure 7.

[0021] According to the construction method of the reactor building 1 according to this embodiment, the construction of the foundation 8 of the reactor building 1 and the assembly of the bottom structure 7 can be carried out in parallel. Therefore, compared to the conventional method in which the bottom 11, vessel wall 12a, main body bottom 31 and main body wall 32a were assembled after the foundation was constructed, the amount of on-site work required is greatly reduced and the construction time is shortened. In particular, the time required for welding inspections is greatly reduced by performing them in advance. Furthermore, since the bottom of the reactor containment vessel 2 and the bottom of the main body 3 are integrated, the bottom of the reactor containment vessel 2 can be installed all at once. Therefore, the effect of reducing construction time is significant. Moreover, by integrating the bottom 11 and the vessel wall 12a, and the main body bottom 31 and main body wall 32a in advance, welding of corners, which takes a lot of time to join, can be carried out in an assembly area where work is easier, thus improving work efficiency.

[0022] Since the base structure 7 is transported before the concrete 16 is poured, and then the concrete 16 is poured after it is installed at the construction site, the transport weight can be reduced. This reduces the load capacity of the lifting equipment, which in turn reduces the cost of the lifting equipment and makes transport easier.

[0023] Furthermore, since the bottom structure 7 is lifted using lifting equipment to transport it to its construction location, the transport can be carried out efficiently. In addition, because the reactor is a light water reactor, the construction time for the light water reactor reactor building 1 can be shortened. Furthermore, since the container wall portion 12a is the lower end portion of the wall portion 12 of the reactor containment vessel 2 that rises from the bottom portion 11 (container mat portion), the container wall portion 12a does not become too large and is of an appropriate size, thereby enabling a reduction in the weight of the bottom structure 7.

[0024] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and each component can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the assembly procedure for the bottom structure 7 is in the order of the bottom 11 which is the container mat part, the container wall part 12a, and the structural bottom part 31 and structural wall part 32a which are the structural mat part, but it is not limited to this. The bottom structure may also be assembled in the order of the container mat part, structural mat part, container wall part and structural wall part.

[0025] Furthermore, in the above embodiment, the concrete 16 is poured after the bottom structure 7 is transported and installed before the concrete 16 is poured, but this is not the only way to do so. If the bottom structure 7 is relatively small and can be transported with the concrete poured, the concrete may be poured in advance during the assembly process.

[0026] Furthermore, in the above embodiment, the reactor containment vessel 2 and the frame 3 are steel-plate concrete structures, but are not limited to this, and may be half-steel-plate concrete structures in which steel plates are provided on only one side of the concrete, or other concrete structures. In addition, the reactor containment vessel 2 (its bottom structure) constructed by the reactor building construction method can be applied to housing boiling water reactor pressure vessels, pressurized water reactor pressure vessels (i.e., for light water reactors), and other types of reactor pressure vessels. It can also be applied to housing reactor pressure vessels of various power outputs, from small to large. [Explanation of Symbols]

[0027] 1. Reactor building 2. Reactor containment vessel (containment vessel) 3 skeleton 7 Bottom structure 11. Bottom (container mat section) 12a Container wall 16 Concrete 31. Bottom of the structure (structure mat section) 32a Structure wall 36 Concrete

Claims

1. A method for constructing a reactor building, comprising an outer structure that houses the containment vessel of the reactor, An assembly process in which the container mat portion, which is the bottom of the aforementioned containment vessel, the container wall portion of the aforementioned containment vessel, the structural mat portion, which is the bottom of the outer structural body, and the structural wall portion of the structural body are integrated in an assembly area, The process includes an installation step of transporting the bottom structure, which was assembled in the aforementioned assembly area, to the construction location and installing it. A method for constructing a nuclear reactor building characterized by the following features.

2. The aforementioned containment vessel and the aforementioned frame are constructed of a steel plate concrete structure. In the installation process described above, the bottom structure is transported and installed before concrete pouring, and then concrete is poured. The method for constructing a reactor building according to feature 1.

3. The transport to the construction location is carried out by lifting the bottom structure using lifting equipment. The method for constructing a reactor building according to feature 1.

4. The reactor is a light water reactor. A method for constructing a reactor building according to claim 1 or 2, characterized by the features described above.

5. A bottom structure that constitutes the bottom of a reactor building, which has an outer frame that houses the containment vessel of the reactor, The container mat portion, which is the bottom of the containment container, the container wall portion of the containment container, the structural mat portion, which is the bottom of the outer structure, and the structural wall portion of the structure are integrally formed. A bottom structure characterized by the following features.

6. The container wall portion is the lower end portion of the wall portion of the storage container that rises from the container mat portion. The bottom structure according to claim 5.

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