Construction method of reactor building, and roof structure

Abstract

To provide a construction method of a reactor building capable of shortening a construction time, and a roof structure.SOLUTION: A construction method for a reactor building 1 comprises an outside skeleton 3 that houses a reactor containment vessel 2 and a crane 50 installed at an inside upper end part of the skeleton 3. The construction method includes an assembly process in which a skeleton wall 32a, which is an upper end part of a wall of the skeleton 3, the crane 50, and a support structure for the crane 50 are integrated into a crane structure 7 in an assembly area, and an installation process in which the crane structure 7 integrated in the assembly area is transported to a construction position and installed. In the assembly process, the crane structure 7 and a skeleton roof (skeleton roof part 33), which is the roof of the skeleton 3, are integrated in the assembly area. In the installation process, a roof structure 6 consisting of the crane structure 7 and the skeleton roof (skeleton roof portion 33) are transported to a construction position and installed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for constructing a nuclear reactor building and a roof structure. [Background technology]

[0002] Known reactor buildings that house a reactor containment vessel include those that employ a steel skeleton, a reinforced concrete skeleton, or a steel-plate concrete skeleton (see, for example, Patent Documents 1 to 3). An overhead crane or a polar crane (hereinafter referred to as a "crane") may be installed inside the reactor building, for example, at the top. When constructing a roof equipped with a crane, as shown in FIG. 5, first, a steel wall 102 is constructed at the top of the reactor building 101 (see FIG. 5A). Then, rails 104 that support the crane are laid on a pair of brackets 103, 103 installed inside the steel wall 102 (see FIG. 5B). After that, a crane 105 is hung between the rails 104, 104 (see FIG. 5C), and finally, a roof 106 is constructed (see FIG. 5D). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-223970 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-57379 [Patent Document 3] Japanese Patent Application Publication No. 5-107381 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional methods for constructing a reactor building have the problem that a series of steps, such as steel walls 102, brackets 103, rails 104, cranes 105, and roof 106, must be constructed in order at the construction site, which requires a lot of time and effort.

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

[0006] In order to solve the above problems, the present invention provides a method for constructing a reactor building comprising an outer structure that houses a reactor containment vessel and a crane installed at the inner upper end of the structure, the method comprising: an assembly process for integrating the structure wall, which is the upper end of the structure wall, the crane, and a support structure for the crane into a crane structure in an assembly area; and an installation process for transporting the crane structure integrated in the assembly area to a construction position and installing it. [Effects of the Invention]

[0007] According to the method for constructing a reactor building and the roof structure of the present invention, construction time can be shortened. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view showing a roof structure constructed by a reactor building construction method according to an embodiment of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing a reactor building constructed by a reactor building construction method according to an embodiment of the present invention. [Figure 3] 1 is a flowchart showing a method for constructing a reactor building according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic side view showing an installation step of the method for constructing a reactor building according to the embodiment of the present invention. [Figure 5A] FIG. 1 is a schematic cross-sectional view showing a process of constructing the upper end of a wall of a framework in a conventional method for constructing a reactor building. [Figure 5B] FIG. 1 is a schematic cross-sectional view showing a process of installing a crane support structure in a conventional method for constructing a reactor building. [Figure 5C] FIG. 1 is a schematic cross-sectional view showing a process of installing a crane in a conventional method for constructing a reactor building. [Figure 5D] 1 is a schematic cross-sectional view showing a process for constructing a building roof in a conventional method for constructing a reactor building. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings as appropriate. Fig. 1 is a schematic cross-sectional view showing a roof structure constructed by a method for constructing a reactor building, Fig. 2 is a schematic cross-sectional view showing a reactor building constructed by the method for constructing a reactor building, Fig. 3 is a flowchart showing the method for constructing a reactor building, and Fig. 4 is a schematic side view showing an installation process of the method for constructing a reactor building.

[0010] First, the configuration of the reactor building 1 will be described. As shown in Fig. 2, the reactor building 1 of this embodiment is a light water reactor type nuclear facility, with a reactor containment vessel 2 located in the center and a skeleton 3 formed on the outside of the reactor containment vessel 2. The reactor containment vessel 2 and skeleton 3 of this embodiment are constructed of a steel plate concrete structure, and are 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. A crane 50 is installed at the top end of the inside of the skeleton 3.

[0011] The reactor containment vessel 2 is a vessel that contains the reactor pressure vessel 4. In addition to the reactor pressure vessel 4, the reactor containment vessel 2 also contains main steam system piping, a recirculation system, and related equipment (not shown). Inside the reactor containment vessel 2, a dry well is formed around the reactor pressure vessel 4. In the event that radioactive materials are released due to fuel damage in the reactor caused by a reactor pressure vessel or loss of reactor coolant accident, the reactor containment vessel 2 serves as a barrier (containment function) to prevent the release of radioactive materials into the environment, ensuring the safety of the general public around the power plant and power plant employees, and is highly airtight.

[0012] The reactor containment vessel 2 comprises a bottom 11, walls 12, and a ceiling 13. The bottom 11 is formed in a circular mat shape in a plan view. The bottom 11 is partitioned by upper and lower steel plates and side steel plates that cover the periphery, and concrete is poured inside.

[0013] The wall 12 has a cylindrical shape and rises from the outer periphery of the bottom 11. The wall 12 is divided by an outer steel plate and an inner steel plate, and concrete is poured inside. The ceiling 13 seals the upper end of the wall 12, and in this embodiment, it has a stepped shape with a higher central portion (see FIG. 2).

[0014] The skeleton 3 is a structure that constitutes the outer building that houses the reactor containment vessel 2, and includes a skeleton bottom 31, a skeleton outer wall 32, and a skeleton roof 33. The skeleton bottom 31 is the lowest floor of the building and is formed on the same plane as the bottom 11. The skeleton bottom 31 is formed to surround the bottom 11, and has a rectangular outer periphery. The skeleton bottom 31 is partitioned by upper and lower steel plates, side steel plates that cover the periphery, and side steel plates of the bottom 11, and concrete is poured inside. The outer periphery of the skeleton bottom 31 is not limited to a rectangle, and may be another shape, such as a circle, depending on the shape of the reactor building 1.

[0015] The skeleton outer wall 32 has a rectangular cylindrical shape and rises from the outer peripheral edge of the skeleton bottom 31. The skeleton outer wall 32 is partitioned by an outer steel plate and an inner steel plate, and concrete is poured inside. The upper end of the skeleton outer wall 32 corresponds to the "skeleton wall 32a." The skeleton outer wall 32 below the skeleton wall 32a is referred to as the "lower skeleton wall 32b" when distinguishing it from the other. The skeleton wall 32a has the same flat cross-sectional shape as the lower skeleton wall 32b, and is installed on top of the lower skeleton wall 32b. The skeleton wall 32a is the part on the inside of which the crane 50 is installed, and is partitioned by an outer steel plate 34 and an inner steel plate 35. At the upper and lower ends of the skeleton wall 32a, connecting plates 36 that connect the outer steel plate 34 and the inner steel plate 35 are installed so as to span between the steel plates 34, 35. Concrete (not shown) is poured inside the outer shell formed by the outer steel plate 34, the inner steel plate 35, and the connecting plates 36, 36. The reactor containment vessel 2, the base body bottom 31, and the lower base body wall 32b are collectively referred to as the lower structure 5.

[0016] As shown in Figure 1, the skeleton roof section 33 covers the upper end opening of the skeleton outer wall section 32, and in this embodiment, has an arch shape extending in the front-to-back direction of the page. The skeleton roof section 33 corresponds to the "skeleton roof." The skeleton roof section 33 is partitioned by an outer steel plate 37 and an inner steel plate 38. Concrete (not shown) is poured inside the outer shell formed by the outer steel plate 37 and the inner steel plate 38.

[0017] The crane 50 is, for example, a hoist-type overhead crane. The crane 50 is configured to be able to travel in the direction in which the skeleton roof portion 33 extends (the front-to-back direction of the paper). The crane 50 is supported on crane travel rails 52 laid on brackets 51 that protrude inward from the skeleton wall 32a. In other words, the brackets 51 and the crane travel rails 52 form the support structure of the crane 50. The brackets 51 are respectively mounted at the same height on the skeleton walls 32a, 32a that are arranged parallel to each other. A pair of crane travel rails 52 is provided, and is mounted on the upper surface of the bracket 51 for each skeleton wall 32a. The crane travel rails 52 extend horizontally along the surface of the skeleton wall 32a in the front-to-back direction of the paper in FIG. 1.

[0018] The crane 50 is equipped with a traverse rail 55 and a hoist 56. The traverse rail 55 is suspended between crane travel rails 52, 52 arranged parallel to each other, and is capable of traveling along the longitudinal direction of the crane travel rail 52. The hoist 56 is engaged with the traverse rail 55, and is capable of moving along the longitudinal direction of the traverse rail 55. A hook 57 is attached to the hoist 56 so that it can be raised and lowered.

[0019] In the reactor building 1 according to this embodiment, the roof structure 6 is formed by integrating the skeleton wall 32a, which is the upper end of the wall of the skeleton 3, the crane 50, the bracket 51 and the crane travel rails 52, which are the support structure for the crane 50, and the skeleton roof portion 33, which is the skeleton roof. The roof structure 6 is formed by first assembling an outer shell made of steel plates, installing it in the construction position, and then pouring concrete into the inside of the outer shell. The skeleton wall 32a, the crane 50, and the bracket 51 and the crane travel rails 52, which are the support structure for the crane 50, may be collectively referred to as the "crane structure 7."

[0020] Next, a method for constructing the reactor building 1 according to this embodiment will be described with reference to Fig. 3. The method for constructing the reactor building 1 includes a substructure construction step, an assembly step, and an installation step.

[0021] The lower structure construction process is a process of constructing the containment vessel 2, the skeleton bottom 31, and the lower skeleton wall 32b (lower structure 5) below the roof structure 6 (St1). The lower structure construction process includes a containment vessel construction process, a skeleton bottom construction process, and a lower skeleton wall construction process. The containment vessel construction process is a process of constructing the containment vessel 2. In the containment vessel construction process, the bottom 11, the wall 12, and the ceiling 13 are constructed in sequence using known procedures. The skeleton bottom construction process is a process of constructing the skeleton bottom 31 of the skeleton 3. In the skeleton bottom construction process, the skeleton bottom 31 is constructed around the outer periphery of the bottom 11 of the containment vessel 2 using known procedures. The lower skeleton wall construction process is a process of constructing the lower skeleton wall 32b of the skeleton outer wall 32 of the skeleton 3. In the lower skeleton wall construction process, a lower skeleton wall 32b is constructed by a known procedure on the skeleton bottom 31. The skeleton bottom construction process and the lower skeleton wall construction process are carried out in parallel with the reactor containment vessel construction process.

[0022] The assembly process is a process for constructing the roof structural body 6 (St2 to St6). In the assembly process, the skeleton wall 32a, the crane 50, the support structure of the crane 50 (brackets 51 and crane travel rails 52), and the skeleton roof portion 33, which is the skeleton roof, are assembled and integrated in the assembly area. In the assembly process, the skeleton wall 32a is first assembled (St2). When assembling the skeleton wall 32a, the outer steel plate 34, the inner steel plate 35, and the connecting plates 36, 36 are welded together to form an outer shell. Note that concrete is not poured into the skeleton wall 32a in the assembly process, but is instead poured after the roof structural body 6 is installed on the substructure 5.

[0023] Next, brackets 51 are installed inside the body wall 32a (St3). A plurality of brackets 51 are attached at a predetermined interval along the longitudinal direction of the crane travel rail 52 at the height of the upper end of the body wall 32a. Thereafter, the crane travel rail 52 is installed (St4). The crane travel rail 52 is suspended and fixed over the brackets 51 attached to the body wall 32a at a predetermined interval. This completes the support structure for the crane 50.

[0024] Then, the crane 50 is installed on the support structure (St5). When installing the crane 50, a traverse rail 55 is suspended between the pair of crane travel rails 52, 52 so as to be able to travel, and a hoist 56 is installed on the traverse rail 55 so as to be able to move.

[0025] Finally, the skeleton roof section 33 is installed on top of the skeleton wall 32a (St6). When installing the skeleton roof section 33, the outer steel plate 37 and the inner steel plate 38 are welded together to form an outer shell. Note that concrete is not poured into the skeleton roof section 33 during the assembly process, but is instead poured after the roof structure 6 has been installed on the substructure 5.

[0026] In the assembly process, the time required for the assembly work is calculated backwards, and the process is planned so that the substructure 5 is completed before the timing of transporting the roof structure 6. In other words, the roof structure 6 is assembled in parallel with the construction of the substructure 5 of the reactor building 1.

[0027] The installation process is a process of transporting (carrying in) the roof structural body 6 to the construction position and installing it (St7). In the installation process, the roof structural body 6 is transported and installed before concrete is poured, and then concrete is poured into the skeleton walls 32a and skeleton roof portion 33. As shown in FIG. 4, the roof structural body 6 is transported and lifted using a lifting device 70 such as a crane, and placed at the construction position (above the substructure 5). The roof structural body 6 is suspended by a wire 72 hanging down from the crane's arm 71. Then, after the roof structural body 6 is suspended above the substructure 5, the skeleton walls 32a are fixed to the lower skeleton walls 32b.

[0028] Next, the effects of the method for constructing the reactor building 1 and the roof structural member 6 according to this embodiment will be described. According to this method for constructing the reactor building 1 and the roof structural member 6, the construction of the substructure 5 of the reactor building 1 and the assembly of the roof structural member 6 can be performed in parallel. This significantly reduces the on-site construction effort and shortens the construction time compared to the conventional method in which the outer wall structure of the reactor building 1 is constructed, followed by the installation of the crane support structure and the crane, and then the roof structure of the reactor building 1 is constructed. Furthermore, because the structural member walls 32a, the support structure for the crane 50, the crane 50, and the roof structure of the reactor building 33 are integrated, the upper part of the containment vessel 2 (roof structural member 6) can be installed all at once. This significantly reduces the construction time. Furthermore, welding of the structural member walls 32a and the roof structure of the reactor building 33 can be performed in an assembly area where the work is easy to perform, improving the working environment.

[0029] The roof structure 6 is transported before concrete is poured, and concrete is poured after the structure is installed at the construction site, so the transport weight can be reduced. This reduces the load capacity of the lifting equipment 70, reducing the cost of the lifting equipment 70 and making transportation easier.

[0030] Furthermore, the roof structural body 6 is transported to the construction site by being lifted using the lifting equipment 70, so transportation can be carried out efficiently. This makes it possible to shorten the construction time for constructing the reactor building 1 of a light water reactor if the reactor is a light water reactor. Of course, if this method is applied to a fast reactor or the like, the construction period for constructing the reactor building can also be shortened.

[0031] Furthermore, because the skeleton wall 32a is the upper end of the skeleton outer wall portion 32, the skeleton wall 32a does not become too large and has an appropriate size, which contributes to reducing the weight of the roof structure 6. Furthermore, the crane 50 and its support structure (brackets 51 and crane travel rails 52) can be installed inside the skeleton wall 32a.

[0032] While the above describes an embodiment of the present invention, the present invention is not limited to the above embodiment, and each component can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the roof structure 6, which includes the skeleton wall 32a, the crane 50, the crane 50 support structure (brackets 51 and crane travel rails 52), and the skeleton roof portion 33, is assembled in a separate assembly area. However, this is not limited to this. The crane structure 7, which is the roof structure 6 excluding the skeleton roof portion 33, may be assembled in the assembly area and transported to and installed on the substructure 5. In this case, the skeleton roof portion 33 is constructed after installation. In this way, even when the crane structure 7 is assembled separately, construction time can be shortened, although not as much as with the roof structure 6. Furthermore, the load capacity of the lifting equipment 70 can be reduced, thereby reducing the cost of the lifting equipment 70.

[0033] In the above embodiment, the roof structure 6 is transported and installed before concrete is poured, but this is not limited to this. If the roof structure 6 is relatively small and can be transported with the concrete poured, concrete may be poured into the skeleton walls 32a and skeleton roof portion 33 in advance during the assembly process.

[0034] Furthermore, in the above embodiment, the skeleton wall 32a and the skeleton roof 33 are made of a steel plate concrete structure, but this is not limiting. For example, the skeleton wall 32a and the skeleton roof 33 may be steel walls made of steel plates, double steel plate walls made of two overlapping steel plates, or may be a half steel plate concrete structure in which steel plates are provided on only one side of concrete, or other concrete structures.

[0035] Furthermore, in the above embodiment, the skeleton roof 33 is arch-shaped, but is not limited to this. The skeleton roof 33 may be flat, or may have the surface shape of a hemisphere or a truncated cone. If the skeleton roof 33 has the surface shape of a hemisphere or a truncated cone, the skeleton outer wall 32 will be cylindrical, and the crane 50 will be supported by annular rails installed along the inner periphery of the skeleton outer wall 32 and rotate within the reactor building 1.

[0036] Furthermore, the shape of the crane 50 is not limited to the configuration of the above embodiment, and cranes of other shapes may be used. For example, the crane may be a hanging type (suspended type) crane. In this case, the bracket is a hanger bracket with a hanging structure, and the crane is suspended from it.

[0037] Furthermore, the reactor containment vessel 2 (its bottom structure) produced by the reactor building construction method can be applied to contain a boiling water type reactor pressure vessel, a pressurized water type reactor pressure vessel (i.e., for a light water reactor), or other types of reactor pressure vessels. It can also be applied to contain reactor pressure vessels of various outputs, from small to large. [Explanation of symbols]

[0038] 1. Reactor building 2. Reactor containment vessel (containment vessel) 3 skeleton 6 Roof structure 7 Crane structure 32a Core wall 33 Body roof section (body roof) 50 Crane 51 Bracket (crane support structure) 52 Crane running rails (crane support structure)

Claims

1. A method for constructing a reactor building comprising an outer skeleton that houses a containment vessel of a nuclear reactor and a crane installed at an upper end of the inner side of the skeleton, an assembly process in which the skeleton wall, which is the upper end of the skeleton wall, the crane, and a support structure for the crane are integrated into a crane structure in an assembly area; and an installation process of transporting the crane structure integrated in the assembly area to a construction site and installing it there. A method for constructing a nuclear reactor building.

2. In the assembly process, the crane structure and the skeleton roof, which is the roof of the skeleton, are integrated in an assembly area, In the installation step, the roof structure, in which the crane structure and the roof frame are combined, is transported to a construction position and installed.

2. The method for constructing a reactor building according to claim 1.

3. The structure is constructed of a steel plate concrete structure, In the installation step, the roof structure including the skeleton wall and the skeleton roof before concrete pouring is transported and installed, and then concrete is poured into the skeleton wall and the skeleton roof.

3. The method for constructing a reactor building according to claim 2.

4. The roof structure is lifted using a lifting device to be transported to the construction site.

3. The method for constructing a reactor building according to claim 2.

5. The reactor is a light water reactor.

5. A method for constructing a reactor building according to claim 1.

6. A roof structure comprising an outer skeleton that houses a containment vessel of a nuclear reactor and a crane installed at an inner upper end of the skeleton, The frame wall, which is the upper end of the frame wall, the crane, the crane support structure, and the frame roof, which is the roof of the frame, are integrally formed. A roof structure characterized by:

Images