JPS6269198A - Method of construction of reactor container - Google Patents

Abstract

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

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a construction method for a nuclear reactor containment vessel.

[Technical background of the invention]

Below, the conventional construction method of the reactor containment vessel is shown in Figure 3 and $
This will be explained with reference to FIG. Here, FIG. 3 shows a longitudinal sectional view of the reactor containment vessel. In Figure 3, a bottom concrete 2 is filled in the reactor containment vessel 1 to adjust the spatial volume, and a lower concrete 3 is tightly packed into the reactor containment vessel 1 to support the bottom concrete 2. . A pressure vessel pedestal (hereinafter simply referred to as the pedestal) 4 is erected on the bottom concrete 2, and a reactor heat shielding wall (hereinafter simply referred to as the The pedestal 4 forming a heat shield wall 5 supports a reactor pressure vessel 6 containing a reactor core (not shown) therein. Further, a suppression chamber 7 is installed around the reactor containment vessel 1, and this suppression chamber 7 is installed around the reactor containment vessel 1.
Pool water 8 is accommodated in φ-7. The suppression chamber 7 and the reactor pressure vessel 1 are connected by a vent pipe 9, and a downcomer 1 is connected to the suppression chamber 7 side of the vent pipe 9 via a vent header 10.
1 is provided, and the tip of this downcomer 11 is open into the pool water 8.

The conventional construction method for the 1st Oji reactor containment vessel shown above is the 4th construction method.
This will be explained with reference to Figures (a) to (a). Note that the same parts as in FIG. 3 are given the same reference numerals, and a description of their combination will be omitted. In Figure 4, the conventional construction method is shown in Figure 4 (a).
) As shown in 5, after the pedestal 4 is constructed on the bottom concrete 2, the lower part of the heat shield t5 is installed. after that,
The heat shield wall 5 is completed by installing the upper part of the heat-A shield 5 as shown in FIG. 4(b). The heat shielding wall 5 is installed with a sufficient distance from the reactor pressure vessel 6 so that the reactor pressure vessel 6 can be carried in safely. After the heat shield wall 5 is completed, the reactor pressure vessel 6 is housed within the heat shield wall 5 and fixed to the pedestal 4 as shown in FIG. 4(c). And reactor pressure vessel 6
After the installation, as shown in Figure 4(d), welding work between the nozzle 12 formed in the reactor pressure vessel 6 and the piping 13 begins, and then the piping work beyond that begins.
We are engaged in construction methods.

[Problems with background technology]

As mentioned above, in the conventional construction method, the reactor pressure vessel is carried in after the completion of the heat shield wall, which is a five-step process. It was necessary to ensure sufficient distance from the heat shield wall. As a result, the diameter of the heat shield wall became larger, and the reactor containment vessel as a whole also became larger, which in turn affected the overall size of the reactor building.

In addition, conventional construction procedures require heat i! After the installation of the i-wall and pressure vessel was completed, welding work for the nozzle and piping formed on the pressure vessel began, and subsequent piping work was then carried out in sequence, making the timing of the delivery of the pressure vessel critical.

[Purpose of the invention]

The present invention provides a construction method for a reactor containment vessel, which involves carrying in the reactor pressure vessel early, carrying out piping work earlier than before to shorten the construction period, and further reducing the diameter of the heat shield wall. The purpose is to obtain.

[Summary of the invention]

The present invention relates to a nuclear reactor in which a reactor pressure vessel is supported by a pressure vessel pedestal that is erected on a concrete bottom and has a reactor heat shielding wall formed on the upper part, and a reactor containment vessel is constructed to store the reactor pressure vessel. Containment vessel h) In the construction method, after the bottom concrete is completed, a pressure vessel pedestal is constructed on this bottom concrete, and after this construction, the lower part of the heat shielding wall is formed, and the lower part of this heat shielding wall is formed. Later, the upper part of the heat shield wall is divided and temporarily placed, and the reactor pressure vessel is carried into the heat shield wall, and after this reactor pressure vessel is carried into the heat shield wall, the reactor pressure vessel is formed. The method is characterized in that the nozzle and the piping are welded together, and after the welding work is performed, the upper part of the temporarily placed heat shielding wall is connected to the lower part. .

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Further, in FIGS. 1 and 2, the same parts as in FIGS. 3 and 4 are given the same reference numerals, and explanations of the configurations of these parts will be omitted. Here, FIGS. 1(a) to (d) show schematic longitudinal cross-sectional views showing one implementation of the present invention + Mi construction method, and FIG. . In Fig. 1, the construction method of the present invention is first shown in Fig. 1 (1).
As shown in Figure 5, after the pedestal 4 is constructed on the bottom concrete 3, the lower part 5a of the heat shielding wall 5 is installed, and the temporary mounting frame I4 is attached to the tip of this lower part 5a. Thereafter, as shown in FIGS. 1(b) and 2, the upper part 5b of the heat shielding wall 5 is carried in a divided form and temporarily placed above the lower part 5a of the heat SU wall 5 in the shape of a flower petal. Note that the heat shield wall 5 is made of a steel plate and is finally completed by pouring concrete inside, but concrete has not yet been poured on the upper heat shield wall 5b. No, the reactor pressure vessel 6 is installed on the pedestal 4 after the upper part 5b of the heat shielding wall 5 is temporarily placed. After the reactor pressure vessel 6 is installed, r
After welding the nozzle 12 and piping 13 of the a child reactor pressure vessel 6, we moved the upper part of the upper wall of the fAR shield wall to the line 5b, which was marked as 5 in Figure 1 (d). installation and piping work will begin at the same time. From the above definition, it is not difficult to move the upper part 5b of the heat shielding wall because the concrete has not yet been placed, and it will be shaped like a petal in December.F)
By moving the upper part 5b of the front wall 5 of the ivy swallow shield 7 in parallel, the upper parts 5h of the respective heat shielding walls 5 can be connected. Furthermore, since the welding work between the nozzle 12 and the pipe 13 has already been carried out at this time, it becomes possible to carry out the work on the pipe after that.

Therefore, in the construction method of the present invention, the construction work of the heat shield wall 5 and the piping work were performed in separate sequences and could not be done at the same time, but with the construction method of the present invention, they can be done in parallel at the same time. This makes it possible to shorten the process. Furthermore, the pressure vessel will be brought in before the heat shielding wall is completed, and the heat shielding wall that was temporarily placed in parts after being brought in will be moved. Therefore, the distance between the reactor pressure vessel and the heat shield wall can be smaller than the conventional size, and the diameter of the heat shield wall can be reduced.

〔Effect of the invention〕

As explained above, in the construction method of the HA reactor containment vessel according to the present invention, the upper part of the heat shielding wall is temporarily placed in the shape of a flower petal, and after the reactor pressure vessel is brought in, it is formed in the reactor pressure vessel. Since the bath contact work between the nozzle and the piping is carried out in advance, it is possible to carry out the subsequent thermal a-melting wall installation work and piping work at the same time, thereby shortening the construction period.

Furthermore, since the heat shielding wall can be moved laterally and installed, the distance between the heat shielding wall and the Utako reactor pressure vessel can be reduced, reducing the heat! It becomes possible to reduce the diameter of the bush. Therefore, it becomes possible to reduce the size of the reactor containment vessel and the reactor building, thereby making it possible to significantly reduce the amount of materials and to achieve rationalization.

[Brief explanation of drawings]

FIGS. 1(a) to 1(d) are schematic vertical cross-sectional views of the main parts of the reactor containment vessel, respectively showing the construction method of the reactor containment vessel of the present invention;
Figure 2 is a cross-sectional view taken from the entry point in Figure 1 (b), Figure 3 is a schematic vertical cross-sectional view of the reactor containment vessel, and Figures 4 (,) - (a) are each a conventional reactor containment vessel. 1. Reactor containment vessel 2. Bottom concrete 3. Lower concrete 4. Pressure vessel pedestal 5. ...Reactor heat shield wall 6...Reactor pressure vessel 12...Nozzle
I3...Piping 14...Temporary mount agent Patent attorney Nori Chika Isao Nobuyuki Mitsumata Hirofumi (Q,)
(/l) Figure 1 Figure 3 (α) (b) Figure 4

Claims (1)

[Claims] Construction of a reactor containment vessel in which a reactor pressure vessel is supported by a pressure vessel pedestal that is erected on a concrete bottom and has a reactor heat shielding wall formed on the top, and a reactor containment vessel is constructed to house this reactor pressure vessel. In the construction method, after the bottom concrete is completed, a pressure vessel pedestal is constructed on the bottom concrete, the lower part of the heat shield wall is formed after this construction, and the lower part of the heat shield wall is formed after the lower part of the heat shield wall is formed. The reactor pressure vessel is carried into the heat shielding wall with the upper part divided and temporarily placed, and after the reactor pressure vessel is carried into the heat shielding wall, the nozzle and piping formed in the reactor pressure vessel are connected. A method for constructing a nuclear reactor containment vessel, comprising performing welding work, and connecting the upper part of the temporarily placed heat shielding wall to the lower part after the welding work is performed.