JPH0634060B2 - Reactor shielding wall installation method - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for installing a nuclear power plant, and more particularly to a method for installing a reactor shielding wall arranged around a reactor pressure vessel.

[Technical background of the invention and its problems] Conventionally, in the method of installing a reactor shield wall, first, a steel form is made into a double-structured cylindrical shape and divided into a plurality of units in the vertical direction, After that, the steel formwork located at the bottom is fixed on the pedestal, and the next steel formwork is stacked and connected on this,
After that, steel molds are sequentially stacked and connected to form an integrated steel mold. Then, concrete is filled in the hollow portion of the integrated steel form to form a reactor shielding wall.

Therefore, until the installation work of this reactor shielding wall is completed, in order to ensure safety and prevent damage to the reactor pressure vessel which is an important component for a nuclear power plant,
The reactor pressure vessel cannot be installed on the pedestal.

If the reactor pressure vessel is first installed on the pedestal and then the reactor shielding wall is installed, the reactor pressure vessel and the reactor shielding wall should be installed between the reactor pressure vessel and the reactor shielding wall during the installation work of the reactor shielding wall. It is not possible to perform piping work to the pressure vessel nozzle.

In particular, in the construction of a nuclear power plant, since the installation of the reactor pressure vessel has a great influence on other installation work, it has been strongly desired to shorten the installation of the reactor shielding wall.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of installing a reactor shielding wall, including a reactor pressure vessel, in which the installation required period is significantly shortened. .

[Outline of the Invention] The present invention provides a steel frame mold having a hollow portion formed as a double cylindrical structure integrally supported on the outside of a reactor pressure vessel via a member to form a pedestal together with the reactor pressure vessel. It is hung on the pedestal, the lower part is fixed on the pedestal, concrete is poured into the hollow part, and then the member supporting the steel formwork to the reactor pressure vessel is removed. It is possible to suspend the reactor pressure vessel on the pedestal and to carry out the installation work in parallel without interfering with the installation work, thereby significantly shortening the installation work period of the nuclear power plant.

[Embodiment of the Invention] An embodiment of a method for installing a reactor shield wall of the present invention will be described below with reference to the drawings. First, a method for manufacturing a steel mold will be described with reference to FIGS. 1 and 2. The steel formwork 1
It is composed of a plurality of unit steel form frames which are cylindrical in a double structure and which are vertically stacked and connected. In addition, in the following description, it is assumed that it is composed of three steel molds 2, 3, 4. The unit steel mold frame 2 is arranged at the lowermost stage, and the cylindrical outer wall 2a and inner wall 2b are welded by a plurality of plate-like or rod-like supports 2c at appropriate intervals to form a space 2d. To do. An annular end plate 2e having an outer diameter substantially equal to that of the outer wall 2a and an inner diameter substantially equal to that of the inner wall 2b is welded to the lower end surface. Where support 2c
Has a shape that does not hinder the injection of concrete into the hollow portion 2d.

The unit steel mold 3 is arranged in the middle stage, and like the unit steel mold 2 described above, it has a cylindrical outer wall 3a and inner wall 3b.
Are welded with a plurality of plate-like or rod-like supports 3c at appropriate intervals to form a space 3d. Where support 3c
Has a shape that does not hinder the injection of concrete into the hollow portion 3d.

The unit steel mold 4 is arranged in the upper stage, and like the unit steel molds 2 and 3 described above, the cylindrical outer wall 4a and inner wall 4b are formed in a plate shape or a rod shape at a plurality of appropriate intervals. The space 4d is formed by welding with the eggplant support 4c. Here, the support 4c has a shape that does not hinder the injection of concrete into the hollow portion 4d.

Then, on the upper surface of the unit steel mold 2 and the lower surface of the unit steel mold 3, the radius of the cross section is appropriately larger than the outer diameter of the nozzle 6a so as to be substantially concentric with the nozzle 6a of the reactor pressure vessel 6. And the opposing semi-circular partition plates 2f and 3e which have the above-mentioned shape and are opposed to each other are welded. Further, on the upper surface of the unit steel mold 3 and the lower surface of the unit steel mold 4, a cross-sectional shape is appropriately larger than the outer diameter of the nozzle 6b so as to be substantially concentric with the nozzle 6b of the reactor pressure vessel 6. The hollow and semicircular partition plates 3f and 4e which are opposite to each other are welded. The semi-circular partition plates 2f, 3e, 3f and 4e described above are the unit steel molds 2, 3
And when dividing the reactor pressure vessel 6 at the positions of the nozzles 6a and 6b. When the steel formwork is divided at positions other than the positions of the nozzles 6a and 6b, the nozzles 6a and 6b should be substantially concentric. Weld each pipe-shaped partition plate.

The unit steel molds 2, 3, and 4 configured in this manner are temporarily attached to the reactor pressure vessel 6 by a plurality of temporary supports 5, respectively, and are connected to each other by connecting plates or outer wall and inner wall not shown. The abutting portions are joined by welding or the like to be integrated. The joint surfaces of the partition plates 2f and 3e and 3f and 4e are also welded.

Next, the reactor pressure vessel 6 to which the steel mold 1 was temporarily attached
Of the lifter 7 as shown in FIG.
And hang it on the pedestal 9 in the reactor lattice vessel 8,
The periphery of the bottom of the steel frame mold 1 (that is, the lower part of the unit steel frame 2) is welded to the upper surface of the pedestal 9. Then, from the upper part of the steel mold 1 (that is, the upper part of the unit steel mold 4) to the space portions 2d, 3d.
While pouring concrete 10 into 4 and 4d, the temporary support 5 which temporarily attaches the steel form 1 to the reactor pressure vessel 6 is removed to form the reactor shielding wall 11. FIG. 4 shows this state.

When the reactor pressure vessel 6 to which the steel formwork 1 is temporarily attached is suspended in the reactor containment vessel 8, the outer diameter dimension of the steel formwork 1 is larger than the opening dimension of the upper part of the reactor containment vessel 8. If it is larger, the uppermost flange 12 of the reactor containment vessel 8 is temporarily removed.

With this configuration, the reactor shielding wall 11 and the reactor pressure vessel 6 can be installed in parallel, so that the construction period of the entire nuclear power plant can be significantly shortened. Taking the case of constructing a nuclear power plant having a capacity of 500 MW or more, for example, it is as follows.

(1) When the reactor pressure vessel 6 is installed after the reactor shield wall 11 is installed, the installation work of the reactor pressure vessel 6 can be expedited during the period required for the steel formwork 1 installation (about 2 months). So, the whole construction period is that much (about 2 months)
Can only be shortened.

(2) Reactor shielding wall after the reactor pressure vessel 6 is installed
When installing No. 11, since it is possible to accelerate the start of the pipe connection work to the nozzle of the reactor pressure vessel 6 for the period required to install the steel formwork 1 (about 3 months), the entire construction work period can be It can be shortened by about 3 months).

Although the steel form 1 is divided into a plurality of parts in the above description,
The steel formwork 1 may be constructed integrally without being divided, and the steel formwork 1 may be temporarily attached to the reactor pressure vessel 6 in the vicinity of the installation location and the lifting machine 7
Alternatively, it may be hung on the pedestal 9.

[Effects of the Invention] Since the present invention is configured as described above, the construction work time of a nuclear power plant can be significantly shortened, the reactor pressure vessel and the reactor shielding wall can be easily positioned, and the installation work can be facilitated. And

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a steel form related to the method for installing a reactor shield wall of the present invention is temporarily attached to a reactor pressure vessel, and FIG. 2 is taken along the line AA in FIG. Sectional view taken in the direction of the arrow and cut, and FIG. 3 is a sectional view showing a state in which the reactor pressure vessel temporarily attached with the steel form shown in FIG. 1 is installed on the pedestal, and FIG. Sectional drawing which shows the state which poured the concrete into the hollow part of the steel form shown in FIG. 5, FIG. 5 is sectional drawing which cut | disconnected along the AA line of FIG. 4, and was seen in the arrow direction. 1 ... Steel formwork 2d, 3d, 4d ... Hollow part 5 ... Temporary support 6 ... Reactor pressure vessel 8 ... Reactor containment vessel 9 ... Pedestal 10 ... Concrete 11 ... Reactor shielding wall

Claims (2)

[Claims] 1. A steel formwork having a hollow portion formed as a cylindrical double structure is integrally supported on the outside of a reactor pressure vessel via a member, and is hung on a pedestal together with the reactor pressure vessel. A method for installing a reactor shielding wall, characterized in that a lower part is fixed on the pedestal, concrete is poured into the hollow part, and then the member is removed. 2. A method for installing a reactor shielding wall according to claim 1, wherein the steel form has a divided structure.