JPS6325313B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a nuclear reactor structure for assembling a floor upper structure provided on a diaphragm floor that divides the inside of a nuclear reactor containment vessel into upper and lower parts, and particularly relates to a method for constructing a floor upper structure. The structure is divided into block-like structures in advance, and these are assembled to form the structure above the floor before constructing the upper side walls of the containment vessel, thereby shortening the construction period of the reactor structure. This invention relates to a method of constructing a nuclear reactor structure that can be shortened as much as possible.

Generally, the so-called MARK-type nuclear reactor has a reactor structure in which the inside of the reactor containment vessel (hereinafter referred to as "PCV"), which is approximately conical and cylindrical and houses the reactor pressure vessel, is divided into upper and lower sections with a diaphragm floor. The structure of nuclear reactor structures is well known, and since conventional nuclear reactor structures require a very long period of time to construct, shortening the construction period has become a major issue.

Here, we will explain the first method of constructing this type of nuclear reactor structure.
To explain based on FIGS. 2 and 2, first, a cylindrical pedestal 2 for supporting the reactor pressure vessel 1 is constructed, and then a cylindrical lower side wall 3a of the PCV 3 is formed. A diaphragm floor 5 is constructed by having one end supported by the pedestal 2 and the other end supported by a column support 4 erected from the bottom of the PCV 3 so as to cover the upper open side of the lower side wall portion 3a. Once the pedestal 2, the diaphragm floor 5, and the lower side wall 3a of the PCV 3 have been constructed in this way, a conical cylindrical upper side wall 3b is placed on the lower side wall 3a of the PCV 3.
While the building is being erected, construction of the diaphragm floor, such as concrete pouring of the diaphragm floor, will be carried out at the same time below.

When the construction of the upper side wall 3b of the PCV 3 is completed, the steel that will be the material of the floor upper structure is divided into enough parts to pass through the upper end flange opening 6 of the PCV 3. The members and the like were repeatedly carried onto the diaphragm floor 5 while being suspended by a crane, and the above-floor structure 7 was installed by joining these carried steel members together.

In parallel with the installation of the above-floor structure 7, various devices, piping, etc. were installed inside the above-floor structure 7.

By the way, in the construction method as described above,
After the PCV 3 is completed, the members of the floor upper structure 7 are to be carried in while being suspended from the upper end flange opening 6, so the dimensions of these members are restricted and it is not possible to carry them in large blocks.
Therefore, the installation of this floor upper structure 7 required a long period of time, and there was an inconvenience that the construction period of the nuclear reactor structure took a long time.

In addition, since various equipment and piping were being installed in this structure in parallel with the installation of the above-mentioned floor structure 7, the installation period took a long time.
This was a contributing factor to the lengthening of the construction period for nuclear reactor structures.

Furthermore, while the upper side wall portion 3b of the PCV 3 was being raised, diaphragm floor work such as concrete pouring was being performed below it at the same time, which resulted in vertical work, which posed a safety problem.

In view of the above-mentioned problems, the present invention has been devised to effectively solve the problems, and its purpose is to form a structure above the floor into a block-like assembly structure that is divided into appropriate parts in advance, this
A method for constructing a nuclear reactor structure that can shorten the construction period of the reactor structure as much as possible by assembling the structure above the floor by assembling the upper side wall of the PCV before constructing it. It is on offer.

Below, the method for constructing a nuclear reactor structure according to the present invention will be explained in detail based on the accompanying drawings.

First, as shown in FIG. 3, a cylindrical pedestal 2 for supporting the reactor pressure vessel 1 is constructed at the center of the installation site where the PCV 3 is to be constructed. As the pedestal 2 is constructed, the lower side wall 3a of the PCV 3 is constructed to surround the pedestal 2.
are sequentially constructed in a cylindrical shape facing upward in the vertical direction, and one end inner edge portion 5a is supported by the completed pedestal 2 inside where the upper end portion of this lower side wall portion 3a should be located. A diaphragm floor 5 is formed so as to cover the upper end of the lower side wall 3a by supporting the outer edge 5b of the other end on a large number of column supports 4 standing upright from the bottom of the PCV.

On the other hand, at the same time as the construction of the pedestal 2, the lower side wall 3a of the PCV 3, and the diaphragm floor 5, the diaphragm floor 5 is formed on the diaphragm floor as shown in FIG. The above-floor structure is formed into a plurality of large block-shaped assembly structures 7a which are appropriately divided. This assembled structure 7a is composed of, for example, a steel frame member 8 that holds the periphery thereof, and a steel plate floor 9 that is formed in multiple stages in the vertical direction. The size of this block-like assembled structure 7a is determined by the PCV upper end flange opening 6.
It is formed into several block-shaped assembled structures 7a that are divided along the vertical direction, for example, depending on the lifting capacity of the crane, regardless of the diameter of the crane (see FIG. 1).

Once the construction of the diaphragm floor 5 and the formation of the plurality of block-shaped assembly structures 7a are completed as shown in FIGS. 3 and 4 in the above manner,
Next, as shown in FIG. 5, the block-shaped assembly structures 7a are sequentially lifted onto the already constructed diaphragm floor 5 by a crane (not shown), and these assembly structures 7a are assembled to form the structure above the floor. Complete the formation of object 7.

At this time, since the conical cylindrical upper side wall portion 3b (see Fig. 1) of the PCV 3 has not yet been constructed, it is possible to easily lift and carry in the block-shaped assembly structure 7a, and Since it is formed into a large block shape, assembly work can be done quickly, and the assembly period can be shortened as much as possible compared to conventional assembly methods.

Once the assembly work of the floor upper structure 7 is completed as described above, the upper side wall portion 3b is successively constructed on the lower side wall portion 3a of the PCV 3 with the upper part inclined in the axial direction of the PCV 3. , diaphragm floor construction such as concrete pouring is performed in parallel on the diaphragm floor 5 located below this. At this time, the construction work of the PCV upper side wall part 3b and the diaphragm floor work are vertical work, but since the floor upper structure 7 has already been assembled as described above, the steel plate floor 9 of this structure is used for both work. For example, even if a worker assembling the PCV upper side wall 3b accidentally drops a work tool, it will be caught by the steel plate floor 9, and will not fall onto the diaphragm floor 5, and the diaphragm Floor construction can be carried out safely.

Further, in the structure 7 above the floor, installation work of various equipment, piping and electrical work, etc. are successively carried out in parallel with the above-mentioned work.

These operations are carried out simultaneously, and as shown in FIG.
complete.

Furthermore, since most of the installation work of various equipment and piping and electrical work that will continue to be carried out in the structure 7 above the floor after the completion of the PCV has already been completed, the construction period can also be shortened.

In summary, according to the present invention, the following excellent effects can be achieved.

(1) Conventionally, when assembling structures above the floor,
After the reactor containment vessel was completed, members were assembled while hanging from the upper end flange opening, but by making the structure above the floor a block-shaped assembly structure, it was possible to assemble the reactor containment vessel before forming the upper side walls of the PCV. This can be assembled in a short period of time.

(2) Conventionally, the assembly work of the structure above the floor, the installation work of various equipment to be installed inside the structure, and the piping and electrical work were performed at the same time, resulting in a long construction period, but the method according to the present invention According to the above-mentioned method, since the structure above the floor can be quickly assembled, the installation work of various equipment can be started quickly, and the construction period can be shortened.

(3) Since the structures above the floor can be assembled first, even if the upper side walls of the reactor containment vessel are being constructed while the diaphragm floor is being constructed below, the structures above the floor can be assembled between them. This allows parallel work to be carried out safely.

(4) Since the method is simple, it can be easily adopted without major changes to conventional construction methods.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing the reactor structure after construction has been completed, Figure 2 is a cross-sectional view taken along the line - in Figure 1, and Figure 3 is a cross-sectional view showing the lower side wall of the reactor containment vessel and the diaphragm floor. FIG. 4 is a plan view showing a block-like assembled structure that is divided into parts for carrying out the method according to the present invention, and FIG. FIG. 3 is a vertical cross-sectional view showing the assembled state of the object. In the figure, 2 is the pedestal, 3 is the reactor pressure vessel, 3a is the lower side wall, 3b is the upper side wall, 4 is the column support, 5 is the diaphragm floor, 6 is the upper end flange opening, and 7 is the floor upper structure. ,7
A is a block-like assembly structure.

Claims (1)

[Claims] 1. A reactor containment vessel whose lower part has a cylindrical lower side wall part and whose upper part has a substantially conical cylindrical upper side wall part whose diameter decreases upward, and which are placed vertically within the containment vessel. When constructing a nuclear reactor structure including a diaphragm floor provided for partitioning and a floor upper structure provided on the diaphragm floor, the floor upper structure formed on the diaphragm floor is blocked. At the same time, a lower side wall of the containment vessel is constructed, and the diaphragm floor is constructed inside the lower side wall, and the block-shaped assembled structure is formed on the constructed diaphragm floor. A method for constructing a nuclear reactor structure, comprising: assembling the above to form an upper floor structure, and then constructing an upper side wall on the lower side wall.