JPH03237391A - Storage container constructing method for nuclear power plant - Google Patents

Abstract

PURPOSE:To mount and structure a diaphragm before a storage container is completed and to shorten the period of construction greatly by mounting a diaphragm floor by a pedestal and a temporary support projected from a temporary steel frame for nuclear reactor construction. CONSTITUTION:The temporary support 12 made of, for example, H-shaped steel is projected and installed on the temporary steel frame 3 on the side of the storage container 4 at the installation position at the height of the diaphragm 7 by lower lining 6a and the receiving rack 13 for the diaphragm floor 7 are fixed mutually by welding or bolt clamping, etc., while abutting on the tip of the temporary support. Then the frame of the diaphragm floor 7 is mounted and fixed to construct the storage container by the arrangement of reinforcement and concrete casting. A nuclear reactor building 2 is constructed by constructing a temporary steel frame 3 and then constructing respective floors 2a according to the progress of the concrete construction of the outer peripheral lower part 4a and outer peripheral upper part 4b of the storage container. Consequently, the diaphragm floor 7 is mounted and constructed in the initial stage of the process and the period of construction of the storage container 4 can be shortened.

Description

[Detailed Description of the Invention] (Objective of the Invention) (Industrial Field of Application) The present invention relates to a method for constructing a primary containment vessel of a nuclear power plant, and in particular, the construction of a concrete secondary containment vessel and the installation and installation of a diaphragm floor. Regarding.

(Prior art) Concerning a concrete containment vessel (hereinafter abbreviated as containment vessel), the conventional vertical cross-sectional view of Fig. 5 and Fig. 2(b)
As shown in the process diagram, a temporary steel frame 3 for constructing the reactor building 2 is installed around the reactor installation position on the excavated bedrock 1.
Build. Next, when the mat 5 is completed by reinforcing the mat 5 at the bottom of the containment vessel 4 and placing concrete, the lower lining 6a that constitutes the inner periphery of the containment vessel 4 is assembled. When the lower lining 6a reaches the height of the diaphragm floor 7, reinforcement, formwork arrangement, and concrete pouring are performed for the outer peripheral lower part 4a of the containment vessel. In addition, in parallel with these operations, the pedestal 9 on which the reactor pressure vessel 8 will be installed will be assembled.The pedestal 9 usually has a steel structure, and is assembled into a large block before being assembled onto the mat 5.
As it is assembled on top, it can be completed in a short construction period. Note that this pedestal 9, the lower lining 6a, and the diaphragm floor 7 form a pressure suppression pool 10, so the framework mounting of the diaphragm floor 7 is carried out by the pedestal 9 and the lower containment vessel 4.
This work is carried out when the concrete in a has reached the height of the diaphragm floor 7, and after this, the upper lining 6b is assembled and the concrete work of the upper outer periphery 4b of the containment vessel is then carried out. Furthermore, after the framework is installed on the diaphragm floor 7, reinforcement and concrete placement will be carried out, and work will be done on the inside of the dry well 11 and the ceiling lining 6C. Therefore, when constructing the concrete containment vessel 4, concrete work on the outer circumferential lower part 4a of the containment vessel was critical.

On the other hand, in the reactor building 2, once the temporary steel frame 3 is constructed, concrete work is carried out using the beams 3a of the temporary steel frame 3 in accordance with the progress of concrete work on the lower outer circumference 4a of the containment vessel and the upper outer circumference 4b of the containment vessel. Floor 2a was being constructed.

(Problem to be solved by the invention) However, in the conventional construction method, the lower lining 6a
After assembling up to the position of the diaphragm floor 7, the diaphragm floor 7 cannot be mounted unless the outer peripheral lower part 4a of the containment vessel is completed by concrete work, which takes a long time.

On the other hand, the pedestal 9 has a steel frame structure and is delivered as a large block and then assembled, so the construction period is short, and a large amount of hand-holding time occurs between the pedestal 9 and the outer peripheral lower part 4a of the containment vessel, resulting in wasted construction time. There was a problem that required a lot of man-hours. Moreover, since construction work cannot be started on the upper lining 6b and inside the dry well 11 until after the diaphragm floor 7 is installed, the delay in installing the diaphragm floor 7 is also a factor that hinders the shortening of the construction period. Furthermore, a pressure suppression pool 1 is formed at the bottom of the diaphragm floor 7.
If the diaphragm floor 7 was not installed in the 0, there would be problems in terms of safety and reduced work efficiency, including being directly affected by the weather since there is no ceiling.

The present invention has been made in view of the above, and its purpose is to advance the containment vessel concrete work by protruding temporary supports from the temporary steel frame for the reactor building, which is constructed prior to the containment vessel. An object of the present invention is to provide a method for constructing a containment vessel for a nuclear power plant, which supports and mounts a diaphragm floor regardless of the situation, shortens the construction period, and improves work safety and efficiency.

[Structure of the invention]

(Means for solving the problem) A temporary steel frame for constructing a nuclear reactor building built on bedrock, a temporary support protruding from the steel frame to support a diaphragm floor, a mantle laid on the bedrock, and A pedestal on which the reactor pressure vessel assembled is installed, and a concrete containment vessel that houses the reactor pressure vessel and pedestal.

This inner lining, a cradle disposed inside the lining and fixed integrally with the temporary support of the temporary steel frame to mount and support the diaphragm floor, and a pedestal mounted on the pedestal and the pedestal inside the containment vessel. It is equipped with a diaphragm floor with a pressure suppression pool at the bottom and a dry well at the top.

(Function) When the lining assembly, which is the inner lining of the containment vessel, reaches the mounting position on the diaphragm floor and the assembly of the pedestal on which the reactor pressure vessel is installed is completed, the lining assembly, which is the inner lining of the containment vessel, hits the pedestal and the temporary steel frame for reactor construction. Since the diaphragm floor is mounted on the temporary supports that have been set up, construction of the diaphragm floor, lining assembly above the diaphragm floor, and drywell construction can be carried out regardless of the progress of concrete work for the containment vessel being constructed around the lining. Furthermore, work inside the pressure suppression pool formed below the diaphragm floor can be carried out safely without being affected by the weather due to the diaphragm floor ceiling.

(Example) An embodiment of the present invention will be described with reference to the drawings.

Note that the same components as those in the prior art described above are designated by the same reference numerals and detailed explanations will be omitted.

As shown in the longitudinal cross-sectional view in Figure 1, the process diagram in Figure 2 (a), and the enlarged cross-sectional view of the main parts in Figure 3, first the reactor (not shown) is placed on the excavated bedrock 1 around the reactor installation position. Construct the temporary steel frame 3 for building the building. Next, reinforcing the mat 5 at the bottom of the containment vessel 4 and pouring concrete. After the mat 5 is completed, the lower lining 6a on the inner periphery of the containment vessel 4 is assembled. do. In parallel with these operations, the pedestal 9 on which the reactor pressure vessel 8 will be installed will be assembled.

This pedestal 9 has a steel frame structure and is assembled into a large block and then assembled on the mat 5, and the lower lining 6
a and the diaphragm floor 7 form a pressure suppression pool 10. Further, a temporary support 12 made of, for example, H-beam steel is protrudingly installed on the containment vessel 4 side of the temporary steel frame 3 at the installation position of the diaphragm floor 7 at the height of the lower lining 6a, and the temporary support 12 made of, for example, H-beam steel is abutted against the tip of the temporary support 12 and the lower lining 6a and the lower lining are connected to each other. The pedestals 13 of the diaphragm floor 7 arranged inside the diaphragm floor 6a are fixed to each other by welding or bolting, and a plurality of anchor bolts 14 are implanted in the lower lining 6a directly in front of the pedestals 13.

Next, when the pedestal 9 is completed to the height of the diaphragm floor 7, the diaphragm floor 7 is placed between the pedestal 9 and a pedestal 13 supported by the temporary support 12 of the temporary steel frame 3 and disposed inside the lower lining 6a. The construction will be carried out by mounting and fixing the framework, placing reinforcements and pouring concrete. Before and after the mounting of the framework of the diaphragm floor 7, reinforcing bars and formwork (not shown) are attached to the outer periphery of the lower lining 6a, and concrete is poured to construct the lower outer periphery 4a of the containment vessel. After constructing the diaphragm floor 7, the upper lining 6a is assembled, and when the concrete work on the lower outer periphery 4a of the containment vessel reaches the temporary support 12, the diaphragm floor 7 is secured to the support frame 13, the lower lining 6a, and the anchor bolts 14. Since it is supported, the temporary support 12 is cut and removed, and concrete work is then carried out on the outer peripheral upper part 4b of the containment vessel. At this time, a part of the temporary support body 12 may be buried in the outer peripheral upper part 4b of the containment vessel. After completion of the diaphragm floor 7, work will be done inside the dry well 11 and ceiling lining 6c.

On the other hand, after the temporary steel frame 3 is constructed, the reactor building 2 is constructed using beams 3a of the temporary steel frame 3 in conjunction with the progress of the concrete construction of the lower outer periphery 4a of the containment vessel and the upper outer periphery 4b of the containment vessel. Construction will be carried out on each floor 2a.
Build.

Therefore, the diaphragm floor 7 is a temporary support 1 installed on the temporary steel frame 3 for the atomic detached house, II2, which is constructed at the beginning of the process.
2 and supported by the pedestal 9, which can be completed in a short construction period, and can be installed and constructed at the beginning of the process, so the construction period of the concrete containment vessel 4 including the reactor building 2 can be shortened, and the pressure can be suppressed. Construction work inside the pool 10 and dry well 11 can be started early, and the work can be carried out safely by installing the ceiling.

The vertical cross-sectional view in Figure 4 shows the state in which the temporary support 12 provided on the temporary steel frame 3 is also used for carrying in materials for reinforcing during the construction of the reactor building 2 and the containment vessel 4, and the diaphragm floor A mole rail hoist 15 is attached to the lower part of the temporary support 12 during the construction of the outer peripheral lower part 4a of the containment vessel before and after the construction of 7.
In addition to suspending the temporary support 12, another temporary support 12a is installed at a different plane position above the temporary support 12 to provide a frame for temporary support of the penetration 16, which is installed for carrying in materials and penetrating the storage container 4. It can also be easily done.

〔Effect of the invention〕

As described above, according to the present invention, the pedestal on which the reactor pressure vessel is installed and the temporary support provided on the temporary steel frame of the reactor building make it possible to install and construct the diaphragm floor before the completion of the containment vessel. The construction period for the vessel can be significantly shortened, and the diaphragm floor can be installed earlier, making work inside the pressure suppression pool and drywell unaffected by weather, improving efficiency and safety.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of one embodiment of the present invention, Figure 2 (a) is a process diagram according to the present invention, Figure 2 (b) is a process diagram according to the conventional construction method, and Figure 3 is the same as Figure 1. Circle■ Enlarged cross-sectional view of the inner part,
FIG. 4 is a vertical cross-sectional view showing the present invention being used for carrying in materials, and FIG. 5 is a vertical cross-sectional view of a conventional containment vessel construction method. 1... Bedrock, 2... Reactor building. 3... Temporary steel frame, 4... Containment vessel, 4a.
... lower part of the outer periphery of the containment vessel, 4b... upper part of the outer periphery of the containment vessel,
5...Matt, 6a...Lower lining, 6b...
Upper lining, 6c...Ceiling lining, 7...
・Diaphragm floor. 8...Reactor pressure vessel, 9...Pedestal. DESCRIPTION OF SYMBOLS 10... Pressure suppression pool, 11... Dry well, I2... Temporary support body, 13... Receiving frame, 1
4...Anchor bolt.

Claims (1)

[Claims] constructing a temporary steel frame for constructing a reactor building around the reactor installation position on bedrock, further laying a mat on the bedrock, and then assembling a pedestal to install a reactor pressure vessel on the mat; At the same time, the lining of the containment vessel is assembled, and at the diaphragm floor installation position, a diaphragm floor receiving stand is provided inside the lining, and a temporary support is protruded from the temporary steel frame and fixed to each other, A diaphragm floor is installed between the receiving frame and the pedestal, and the construction of the diaphragm floor, the assembly of the lining above the diaphragm floor, the work inside the dry well, and the concrete work of the containment vessel around the lining are simultaneously carried out, A method for constructing a containment vessel for a nuclear power plant, characterized in that when the concrete work around the lining reaches the temporary support, the temporary support is removed and the concrete work around the lining is continued.