JPS6365398A - Method of assembly construction of nuclear-reactor container - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a method for assembling a nuclear reactor containment vessel. This invention relates to a method for assembling a reactor containment vessel that can be carried out smoothly.

(Prior Art) A reactor containment vessel in a nuclear power plant is provided to prevent radioactive materials from dispersing outside the nuclear power plant during reactor operation and during a reactor coolant loss accident.

The reactor containment vessel 1 is generally constructed as a spherical vessel made of steel inside a reactor building 2 made of reinforced concrete, as shown in FIG. The reactor building 2 is installed on a curved carrot 5 supported by a base concrete 3 at the bottom and a cylindrical cylinder wall 4. Furthermore, inside the reactor containment vessel 1, an internal concrete structure 6 such as a support frame for the reactor is constructed, and at the upper end of the cylindrical crane wall 7 is a polar crane 8 for carrying in and out of equipment and for maintenance.
is being elevated.

Conventionally, the method of assembling the reactor containment vessel with the above structure is as shown in Fig. 7.
The procedure was as shown in Figure 8.

That is, as shown in FIG. 7, following the pouring of the base concrete 3 of the reactor building, the cylindrical cylinder wall 4 is poured.
A spherical carrot 5 is formed, and block plates 9 formed to a predetermined curvature are arranged on the carrot 5 and joined together to form the lower part of the reactor containment vessel. The reactor containment vessel 1 has a ring-shaped block wall A formed by arranging the smallest block plates 9 in the circumferential direction, which are regulated by the lifting capacity of the assembly lifting machine. , 1st stage A, 2nd stage A2, 3rd stage A
It is constructed integrally by stacking 3 and joining each other. FIG. 7 shows a state in which the reactor containment vessel 1 has been constructed up to the third stage.

At the stage when the assembly of the reactor containment vessel 1 is completed up to the third stage, construction of the internal concrete structure 6 within the reactor containment vessel 1 is started in parallel. That is, as shown in FIG. 8, in parallel with the assembly work of internal concrete structures 6 such as the reactor support frame and cylindrical crane walls 7, the fourth to seventh stages of the reactor containment vessel 1 are being assembled. Up to this point will be constructed. By the time the ring-shaped block wall A7 of the seventh stage is assembled, the construction of the cylindrical crane wall 7 is completed, and the polar crane 8 is mounted on top of the cylindrical crane wall 7.

Here, during the assembly work of the reactor containment vessel 1, up to the stage of assembling the ring-shaped block wall A3 of the third stage shown in FIG. Up to the stage of assembling the ring-shaped block walls A4 to A7 from the fourth stage to the seventh stage shown in Figure 1, supports are taken from the internal concrete structure 6, etc., and the work scaffold is assembled on the supports. Assembling and welding of the block plate 9 and the ring-shaped block wall A were carried out using a work scaffold.

Furthermore, the assembly of the 8th stage to the 11th stage of the reactor containment vessel 1 is performed sequentially. In this assembly work, a work scaffold 10 is constructed on the cylindrical crane wall 7 and the above-mentioned polar crane 8 that has already been mounted, and this work scaffold 10 is used to construct the block plate 9 and the upper part of the reactor containment vessel 1. A series of work including assembly, welding, inspection, and painting of ring-shaped block wall A was being carried out. After the installation of the reactor containment vessel 1 is completed in this way, the work scaffolding 10 is dismantled and removed, and the polar crane 8 is readjusted and tested. Equipment such as pressure vessels and steam generators were brought in and installed.

(Problems to be Solved by the Invention) However, in the conventional reactor containment vessel assembly method as described above, the work scaffold 10 used when assembling the upper ring-shaped block walls A8 to A11 of the 8th and subsequent stages is The support of the cylindrical crane wall 7 and the polar crane 8
Since the work scaffold 10 was assembled on this support each time it was used, the polar crane 8 was occupied for the work scaffold, and the subsequent assembly work was interrupted. In other words, since the construction of the Polar Crane 8 will be restarted after the completion of the construction of the reactor containment vessel 1, it is often determined by the progress of the upper part construction of the reactor containment vessel 1. , there was a risk that the entire process would be delayed.

Furthermore, providing a support protruding from the main body of the polar crane 8 and constructing a work scaffold on this support also poses construction and work safety problems.

That is, the number of man-hours required for removing and repairing the support material fixed to the main body of the polar crane 8 is high, and furthermore, there is a problem that the strength of the crane main body is reduced due to the influence of heat. Furthermore, the work scaffold 10 installed on the polar crane 8, which is originally a movable structure, is not a fixed scaffold and is extremely unstable, causing the problem of lowering work safety as it swings during use. there were.

The present invention was devised to solve the above problems, and when performing the assembly work of the upper part of the reactor containment vessel 1, the assembly work of the polar crane does not affect the culm in any way, and each can carry out assembly work,
Another object of the present invention is to provide a method for assembling a reactor containment vessel, which allows for easy construction and dismantling of work scaffolding, and also ensures the safety of workers.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the method for assembling a reactor containment vessel according to the present invention includes a step of connecting block plates in the circumferential direction to form a lower ring-shaped block wall. The steps of sequentially assembling and joining the lower edge of the block plate to one edge of this ring-shaped block wall to form an upper ring-shaped block wall are repeated to form an integrated reactor containment vessel having a predetermined shape. In a method of assembling a reactor containment vessel, scaffolding elements are integrally fixed in advance to both sides of the block plate at least along the circumferential direction, and the block plates integrated with the scaffolding elements are connected in the circumferential direction to form a ring. The main idea is to form a work scaffold around the entire circumference of the block wall, and use this work scaffold to carry out work such as assembling the block plates together, welding, finishing, inspecting, painting, etc.

(Function) According to the assembly method with the above configuration, scaffolding elements are firmly attached in advance to both sides of the block plates, which are the constituent materials of the reactor containment vessel, and the block plates are arranged in a row in the circumferential direction.
At the same time as forming a ring-shaped block wall, a strong work platform can be formed around the entire circumference of the ring-shaped block wall.

This work scaffold is provided integrally with the block plate and is independent from the polar crane or the internal concrete structure. Therefore, the reactor containment vessel assembly process and the polar crane assembly process do not affect each other independently, and the construction process can proceed in parallel. Therefore, the installation period for the reactor containment vessel and its internal equipment can be shortened.

Furthermore, since the work scaffold created in this assembly process is firmly fixed to the block plate, it is stable and does not swing during use, ensuring sufficient work safety.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 8, up to the stage of assembling the seventh ring-shaped block IA, the work was carried out on supports protruding from the carrot 5 or the internal concrete structure 6, similar to the conventional assembly method. Perform work using scaffolding.

The assembly method of the present invention is applied when assembling the ring-shaped block wall A-A11 from the 8th stage onwards.

When the assembly of the seventh stage ring-shaped block wall A7 of the reactor containment vessel 1 is completed, the assembly of the eighth stage ring-shaped block wall A8 is subsequently started. To assemble the eighth stage ring-shaped block wall A8, first, as shown in Fig. 1, block plates are divided into sizes regulated by the lifting capacity of the installation lifting machine, and then bent into a predetermined shape. Prepare 9,
Scaffolding elements 11 are integrally fixed in advance to both surfaces of this block plate 9 at least along the circumferential direction. The scaffolding element 11 is
It is detachably attached to the block plate 9 on the ground in advance by welding or via an attachment jig. In FIG. 1, an example is shown in which it is fixed to a block plate 9 via a contact plate 12. Note that the scaffolding elements of each block plate 9 are attached at positions that are at the same level in the circumferential direction when adjacent block plates 9 are joined, and at positions that facilitate welding and inspection of the joints.

The block plates 9 integrated with the scaffolding elements 11 are successively suspended over the upper circumference of the seventh stage ring-shaped block wall A7, and after mutually adjusting the installation positions, welded from the inside and outside surfaces to form the eighth stage. A ring-shaped block wall A8 is formed. The scaffolding elements 11 fixed to each block plate 9 are connected to each other as shown in FIG. 2 to form an annular working scaffold 10 around the entire inner and outer surfaces of the ring-shaped block wall A8.

Using this work scaffold 10, a series of operations such as assembly, welding, finishing, and inspection of the ninth stage ring-shaped block wall A9 are performed. In assembling the ninth stage ring-shaped block wall A9, as shown in FIG. Scaffolding elements 11 are provided. The block plate 9 made by solidifying this scaffolding element 11 is the 8th stage ring-shaped block! They are disposed on the upper circumference of A8 and joined together to form a ninth stage ring-shaped block wall A9.

Using the annular work scaffold 10 formed on the wall surface circumference of the 9th stage ring-shaped block wall A9, welding of vertical joints between the block plates 9 arranged in the 9th stage and vertically adjacent Ring-shaped block wall A8. Welding work for the circumferential joint with A1o is carried out.

Thereafter, the tenth stage ring-shaped block wall A1o is assembled according to the same procedure. Furthermore, the 11th stage block IA1, which is the top of the spherical reactor containment vessel. After several block plates are joined together on the ground in advance, they are hung onto the upper edge of the ring-shaped block wall A1o of the 10th stage and joined together. Since the work scaffold at this time is a work scaffold fixed to the ring-shaped block wall A1° of the 10th stage, there is no need to attach a scaffolding element to the block wall A11 at the top of the head of the 11th stage.

In addition, three or four block plates may be joined together on the ground and integrated, depending on the lifting capacity of the lifting machine, and the integrated structure may be suspended.

Through the above procedure, the block plates above the eighth stage ring-shaped block wall A8 of the reactor containment vessel 1 are successively suspended and joined to construct the reactor containment vessel 1 of a predetermined height. Fourth
The figure is a plan view showing the arrangement of the work scaffold 10 when all the block plates 9 have been assembled, and the block plates 9 to which the scaffold elements 11 are fixed in advance are arranged in the circumferential direction and then joined. A remarkable ring-shaped block wall A to A1o is formed. Scaffold elements 11 are also connected to form an annular work scaffold 10 at each stage, and subsequent operations such as assembly, welding, finishing, and inspection of block plates 9 can all be performed using this work scaffold.

In addition, as shown in FIG. 5, the annular work scaffold 10 formed on the inner peripheral surface of the reactor containment vessel 1 includes a temporary communication staircase to connect the upper work scaffold and the lower work scaffold. 1
3 is hung. Furthermore, if annular tracks are provided on the upper and lower work scaffolds formed on the inner circumferential surface, and the connecting stairs 13 are pivotably stretched over the two tracks, the original structure can be achieved. Workability on the inner circumferential surface of the secondary containment vessel 1 is further improved.

Note that the work scaffold 10 and the communication stairs 13 provided on the inner peripheral surface of the reactor containment vessel 1 have a structure that is supported by the block plate 9 itself, and do not affect the polar crane 8 in any way. It will be installed so as not to interfere with the assembly of the crane 8 and its post-assembly test run and use.

As described above, in the assembly method of this embodiment, scaffolding elements are fixed in advance to the inner and outer surfaces of each block plate, and at the same time as each block plate is joined, the scaffolding elements are also connected to form an annular work scaffold. This work place can be used for subsequent work such as assembly and welding. In addition, since this work scaffold does not pose an obstacle to the assembly and running of the Polar Crane, the upper assembly process of the reactor containment vessel is independent from the assembly process of the Polar Crane, and has the effect that both can be carried out in parallel. It is possible to shorten the period.

In addition, the work scaffolding is not assembled on supports extending from the polar crane as in the past, but is firmly fixed to each block plate in advance, providing workers with a stable scaffolding without swinging. can. In addition, the construction and dismantling of huge amounts of scaffolding work is reduced, improving the assembly efficiency and workability of the reactor containment vessel.

C Effects of the Invention] As explained above, according to the assembly method of the present invention, the work scaffold is fixed to each block board in advance, so it is possible to provide the worker with a stable work scaffold that does not shake. .

Additionally, there is no need to install additional scaffolding supports on the Polar Crane, and there is no need to transport scaffolding materials to high places and assemble and dismantle them, greatly improving construction efficiency.

Additionally, this assembly method does not pose any hindrance to the assembly process and use of the Polar Crane, and allows the assembly of the reactor containment vessel and the assembly and use of the Polar Crane to proceed in parallel and independently from each other. can. Therefore, the construction work for the reactor containment vessel and auxiliary equipment can be significantly shortened.
It has characteristics such as being able to reduce construction costs.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a block plate to which scaffolding elements are fixed, used in the assembly method of the present invention, and FIG. 2 is a plan view showing the eighth stage ring-shaped block wall assembled by the method of the present invention. FIG. 3 is a perspective view of the two-stage scaffolding element (not showing the block board), FIG. 4 is a plan view showing the arrangement of the work scaffold provided by the construction method of the present invention, and FIG. Fig. 6 is a sectional view showing the mounting structure of the reactor containment vessel, and Fig. 7 shows the reactor containment vessel assembled up to the third stage ring-shaped block wall. 8 is a cross-sectional view showing the reactor containment vessel assembled up to the wall of the seventh stage ring-shaped block. 1... Reactor containment vessel, 2... Reactor building, 3...
・Base concrete, 4... Cylinder wall, 5...
Carrot, 6... Internal concrete structure, 7...
・Cylindrical crane wall, 8...Polar crane, 9...
・Block board, 10... Working scaffold, 11... 2nd place element, 12... Standing board, 13... Communication staircase, A...
Ring-shaped block wall, A1...First stage ring-shaped block wall, A2... Second stage ring-shaped block wall, A3
...Third stage ring-shaped block wall, An...Nth stage ring-shaped block wall, A11... Top of head block wall. Representative Patent Attorney Noriyuki Chika Yudo Hirofumi Mimata 3i1 Figure 4

Claims (1)

[Claims] A process of connecting block plates in a circumferential direction to form a lower ring-shaped block wall, and sequentially assembling and joining the lower edge of the block plate to the upper edge of this ring-shaped block wall to form an upper ring-shaped block wall. In the method for assembling a reactor containment vessel in which an integrated reactor containment vessel having a predetermined shape is formed by repeating the step of forming the reactor containment vessel, scaffolding elements are integrally fixed in advance to both sides of the block plate at least along the circumferential direction. death,
The block plates integrated with this scaffolding element are connected in the circumferential direction to form a work scaffold around the entire circumference of the ring-shaped block wall, and this work scaffold is used to assemble, weld, and finish the block plates together.
A method of assembling a reactor containment vessel characterized by carrying out work such as inspection and painting.