JPS6325314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing internal structures installed in a nuclear reactor containment vessel.

Generally, a so-called MARK-I type nuclear reactor structure is known as a structure of a boiling water reactor, which is equipped with a reactor containment vessel provided with an annular suppression chamber on its outer periphery. Inside the vessel, a large number of piping systems, such as a primary cooling system, a recirculation system, or a core cooling system, and various devices associated with these piping systems are installed.

Since these piping and equipment are installed over almost the entire height of the reactor containment vessel, it is necessary to position and install the piping and equipment at predetermined positions within the reactor containment vessel. It is necessary to provide an internal structure as a support structure and a structure (referred to as a pipe whip structure) to prevent the pipe from running out of control when the internal pipe breaks. Therefore, conventionally, in order to install the above-mentioned internal structure inside the reactor containment vessel, the installation method shown in FIGS. 1A to 1C, for example, has been adopted.

An example of this conventional installation method is to first form a foundation 2 on which the reactor containment vessel 1 is installed by pouring concrete (see Figure 1A), and then place the reactor containment vessel 1 on the foundation 2. A lower spherical shell 1a constituting the lower part is installed, and a cylindrical pedestal 4 supporting the reactor pressure vessel 3 is installed in the lower spherical shell 1a.
Then, on the lower spherical shell 1a, an intermediate cylinder 1b constituting the intermediate part of the reactor containment vessel 1 is arranged in series, and then an upper part of the reactor containment vessel 1 is constructed on the intermediate cylinder 1b. The upper spherical shells 1c are arranged in series to form the entire reactor containment vessel 1 (see FIG. 1B), and then from the upper opening 5 of the reactor containment vessel 1 (that is, the upper opening of the upper spherical shell 1c). , the internal structure 6 on the upper part of the pedestal 4 is installed by dividing the steel material, which is the constituent material of the internal structure 6, into small pieces that can be carried in through the opening 5, and then assembling the steel materials. (See Figure 1c).

By the way, in such a construction method, the steel materials constituting the internal structure 6 must be divided into smaller pieces than the opening 5 of the reactor containment vessel 1, and as a result, the number of times steel materials are brought in increases, and It takes a long time to assemble the steel materials, and there is a risk that the construction period for the reactor building will be extended.

In addition, work to install piping and various equipment inside the reactor containment vessel 1 will be carried out after the installation of the internal structures 6 is completed, so from this point of view as well, the construction period for the reactor building will be prolonged. There is a risk of inviting

The present invention has been made to address the above-mentioned circumstances, and its purpose is to form a pedestal in the reactor containment vessel when the reactor containment vessel is formed halfway, and then By forming the entire reactor containment vessel after the structures are installed, it is possible to install the internal structures as a unit, thereby reducing the work period for installing internal structures and constructing a nuclear power plant. An object of the present invention is to provide a method for installing internal structures of a reactor containment vessel that can be significantly shortened.

Hereinafter, the present invention will be explained according to the steps shown in FIGS. 2A to 2D.

First, as shown in FIG. 2A, a foundation 2 for installing the reactor containment vessel 1 is formed by pouring concrete.

Next, as shown in FIG. 2B, a lower spherical shell 1a constituting the lower part of the reactor containment vessel 1 is installed on the foundation 2, and a pedestal 4 of a predetermined height is formed within the lower spherical shell 1a. .

Next, as shown in FIG. 2C, an internal structure unit 6a, which is divided into a plurality of blocks and is made into a unit by attaching piping P and its auxiliary equipment V, etc., is attached to the upper outer periphery of the pedestal 4 in an annular shape. After installation, these internal structure units 6a... are interconnected to form an annular internal structure 6. Furthermore, in the piping P and the incidental equipment V,
Perform the necessary work (for example, welding of pipes to be connected).

Then, as shown in FIG. 2D, the lower spherical shell 1
After welding an intermediate cylinder 1b constituting the intermediate part of the reactor containment vessel 1 on the upper part of the reactor containment vessel 1, weld the upper spherical shell 1c constituting the upper part of the reactor containment vessel 1 onto the intermediate cylinder 1b. The upper spherical shell 1c and the intermediate cylinder 1b form the internal structure 6.
By surrounding the reactor containment vessel 1, the formation of the reactor containment vessel 1 and the installation of the internal structure 6 are completed.

Therefore, when the internal structure 6 is installed in the reactor containment vessel 1 through the process described above, the internal structure 6 can be divided into a plurality of blocks and installed as a unit by attaching piping and incidental equipment. This simplifies the installation work and significantly shortens the construction period.

Furthermore, while various works are being carried out on the piping and ancillary equipment, the installation work of the intermediate cylinder 1b and upper spherical shell 1c can be carried out in parallel, and from this point of view as well, the construction period can be shortened. .

Furthermore, by providing multiple levels of work floors in the internal structure 6, it is possible to perform up and down work inside the reactor containment vessel 1 in parallel,
Work safety can be improved by separating the upper and lower work spaces.

As explained above, according to the present invention, it is possible to provide a construction method for installing an internal structure of a nuclear reactor containment vessel that can exhibit excellent effects.

[Brief explanation of the drawing]

In the drawings, FIGS. 1A to 1C are process explanatory diagrams showing an example of the conventional construction method, and FIGS. 2A to 2D are process explanatory diagrams showing the construction method of the present invention. 1...Reactor containment vessel, 1a...Lower spherical shell, 1
b...Middle cylinder, 1c...Upper spherical shell, 2...Foundation, 3...Reactor pressure vessel, 4...Pedestal,
6... Internal structure, 6a... Internal structure unit, P... Piping, V... Equipment.

Claims (1)

[Claims] 1. A foundation for installing the reactor containment vessel was formed, a lower spherical shell constituting the lower part of the reactor containment vessel was installed on the foundation, and a pedestal supporting the reactor pressure vessel was formed within the lower spherical shell. Later, an internal structure divided into a plurality of parts and unitized was installed on the pedestal, and then an intermediate cylinder constituting the intermediate part of the reactor containment vessel was connected to the lower spherical shell. A reactor containment vessel characterized in that an upper spherical shell constituting an upper part of the reactor containment vessel is disposed in series on the intermediate cylinder, and the upper spherical shell and the intermediate cylinder surround the internal structure. Installation method for internal structures.