JP2952008B2 - Construction method of boiling water reactor pressure vessel pedestal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a construction method of an improved boiling water reactor pressure vessel pedestal.

(Prior art) The reactor pressure vessel (hereinafter referred to as RPV) pedestal of a nuclear power plant (hereinafter referred to as ABWR) using an improved boiling water reactor (hereinafter referred to as ABWR) 3
It is constructed as shown in FIGS. A, 3B and 4. First, after constructing the reactor building mat 10 and completing the construction, a block of the RPV pedestal 1 constituting the base of the RPV pedestal is suspended by a crane thereon,
Install in place. The joint between the block of the RPV pedestal 1 and the reactor building mat 10 is fixed by an anchor bolt (not shown). Next, the previously manufactured vent pipe 2 is also suspended by a crane, and RP
Attach it to the block of V pedestal 1 and fix it.

The block of the RPV pedestal 1 forms a part of a cylinder whose cross section is thick, and semicircular grooves are provided on both side surfaces thereof. Thus, the vent pipe 2 is attached by engaging with the semicircular groove on one side.

Although only three RPV pedestal blocks 1a to 1c are shown in FIG. 4, the installation of these pedestal blocks is performed sequentially and the corresponding vent pipes 2a to 2c are attached. The lower part of the cylindrical RPV pedestal shown in FIGS. That is, the installation and installation of the RPV pedestal block 1a and the vent pipe 2a, the RPV pedestal block 1b and the vent pipe 2b, the RPV pedestal block 1c and the vent pipe 2c are sequentially performed. When attaching the RPV pedestal block 1b, a vent pipe 2a having a semicircular groove on one side thereof attached to the RPV pedestal block 1a
To be engaged. Also, the vent pipe 2b is attached by engaging with a semicircular groove on the other side of the RPV pedestal block 1b.

Next, R is formed on the lower part of the RPV by the same method as described above.
The RPV pedestal 1 is completed by installing the PV pedestal block, attaching the communication pipe 3 and the air conditioning duct 4 to form the upper stage of the RPV pedestal.

The joint of each of the RPV pedestal blocks is fixed by welding.

When the RPV pedestal 1 is completed as described above,
The space inside is filled with concrete.

In the figure, reference numeral 11 denotes an RPV, which is mounted on the RPV pedestal 1 after the RPV pedestal 1 is completed as described above and fixed by anchor bolts (not shown).

(Problems to be Solved by the Invention) The above-mentioned conventional RPV pedestal construction method has the following problems. In other words, when installing the RPV pedestal block, the pedestal block must be centered and positioned with stay wires and the like to prevent it from falling down, but this operation is quite troublesome.

Furthermore, since a plurality of RPV pedestal blocks are combined into a cylindrical shape, and the space between them is fixed by welding, unless the arrangement of the RPV pedestal blocks and distortion during welding are sufficiently considered, a cylindrical perfect circle is formed. Inability to gain a degree.

In addition, since the RPV pedestal block, vent pipe, air conditioning duct, etc. are assembled on site, the number of man-hours required on-site increases and the installation period is prolonged. (This is the cause of the prolongation of the nuclear power plant construction period. Is also).

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an RPV pedestal construction method capable of shortening the construction period of an RPV pedestal and improving RPV completion accuracy.

[Constitution of the Invention] (Means for Solving the Problems) The pedestal construction method of the present invention, when constructing a reactor pressure vessel pedestal of a boiling water nuclear power plant, requires different workability from the construction site of the pedestal. In a good place, the upper and lower pedestals are divided vertically.
The upper pedestal is equipped with an air conditioning duct, and the lower pedestal is assembled with a vent pipe. ,
Thereafter, the upper pedestal and the lower pedestal are separated again, transported to the construction site, installed and assembled, and then these are welded and connected.

(Function) In the RPV pedestal construction method of the present invention comprising the above steps, in the environment of a factory or the like, each division section completed in advance in a place with good workability is combined at the RPV pedestal construction site,
Since only the connection is required, the construction period of the on-site work can be remarkably reduced as compared with the conventional construction method which requires on-site assembly of the RPV pedestal block, the vent pipe, the communication port, the air conditioning duct, and the like.

In addition, each divided section is manufactured in a place with good workability while checking roundness, and vent pipes, communication ports, air conditioning ducts, etc. are also incorporated into them, so that high precision RPV pedestal and can do.

(Embodiment) FIG. 1 is a perspective view of an intermediate step of one embodiment of the present invention, in which the same parts as those in FIG. 3 are denoted by the same reference numerals, and FIG. 2 compares the RPV pedestal construction method of the present invention with that of a conventional method. FIG.

In the RPV pedestal construction method of the present invention, the lower part 1d of the RPV pedestal is manufactured by dividing it into several blocks in a place such as a factory where the environment and workability are good. In parallel with this, the vent pipe 2 is divided and manufactured, and after its completion, a pressure resistance test, a dimensional inspection, and the like are performed to prepare for the assembly of the lower RPV pedestal 1d.

The RPV pedestal block manufactured by dividing into several blocks is assembled into a cylindrical shape together with the vent pipe 2 while ensuring roundness. The procedure for incorporating the vent pipe 2 differs depending on the mode of the block division. Complete the lower part of the RPV pedestal as described above.

Next, the upper RPV pedestal 1e is manufactured by the same manufacturing procedure as the lower RPV pedestal 1d. In parallel with this production, the communication port 3 and the air-conditioning duct 4 were also produced and assembled in the same manner as the assembly procedure in the lower 1d of the RPV pedestal.
Complete the upper pedestal 1e.

After completing the lower RPV pedestal 1d and the upper RPV pedestal 1e as described above, combining them and confirming the overall dimensions and the like, the manufacture of the RPV pedestal 1 is completed.

The RPV pedestal 1 completed as described above is transported to the site while being separated into the lower RPV pedestal 1d and the upper RPV pedestal 1e. In the field, the reactor building mat
After completion of 10, the lower RPV pedestal 1d produced and transported as described above is suspended by a crane, positioned at a predetermined position, and fixed. Next, RPV pedestal upper 1e
Is suspended by a crane in the same manner as described above, placed on the lower RPV pedestal 1d, positioned, and welded at the joint.

The above construction procedure is shown as procedure A in FIG. In FIG. 2, procedure B shows a construction procedure in a conventional construction method. From this figure, in the construction method of the present invention, in the environment such as a factory, the upper stage 1d of the RPV pedestal and the lower stage 1e of the RPV pedestal completed in advance in a place with good workability need only be combined and combined on site, It can be seen that the work period of the work can be significantly shortened as compared with the conventional construction method requiring the procedure B.

Moreover, in the construction method of the present invention, the roundness of the lower RPV pedestal 1d and the upper RPV pedestal 1e are confirmed at the time of manufacturing the factory, and the RPV pedestal 1 is completed. Therefore, the installation accuracy of the RPV pedestal 1 is improved.

The present invention is not limited to the above embodiment. For example, a cylindrical RPV pedestal may be divided into a plurality of three or more sections in a plane perpendicular to the axis, manufactured for each of the divided sections, and these may be carried to the site to be combined and installed.

[Effects of the Invention] As is clear from the above, in the RPV pedestal construction method of the present invention, the RPV pedestal is divided into a plurality of sections, and each section is separated from the reactor construction site in a different environment and a factory with good workability. And so on, and the divided sections are carried into the site and installed, so that the construction period required for the construction of the RPV pedestal and therefore the construction period required for the construction of the reactor can be shortened.

In addition, each divided section is manufactured in a place with good workability while checking roundness, and a vent pipe, a communication port, an air conditioning duct, etc. are incorporated therein, so that high accuracy is achieved. be able to.

Furthermore, since the work on the reactor building mat can be minimized, the safety and efficiency of the construction work can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an intermediate process of an embodiment of the present invention, FIG. 2 is a process diagram showing a comparison between the RPV pedestal construction method of the present invention and a conventional method, and FIG. 3A is the construction of a conventional RPV pedestal. FIG. 3B is a longitudinal sectional view of the RPV pedestal for explaining the method of construction, FIG. 3B is a sectional view taken along the line BB of FIG. 3A, and FIG. 4 is a perspective view at an intermediate stage of the conventional RPV pedestal construction method. 1 RPV pedestal, 1a to 1c RPV pedestal block, 1d RPV pedestal lower, 1e RPV pedestal upper, 2, 2a to 2c Vent pipe 3, Communication port 4, Air conditioning duct , 10 …… Reactor building mat, 11 …… RPV

Claims (1)

(57) [Claims] When constructing a reactor pressure vessel pedestal of a boiling water nuclear power plant, in a location having good workability different from the construction location of the pedestal, the upper pedestal and the lower pedestal are divided vertically. The upper pedestal is equipped with an air conditioning duct, and the lower pedestal is fitted with a vent pipe. Thereafter, the pedestal is separated again into an upper pedestal lower stage and a lower pedestal lower stage, and then transported to the above-mentioned construction site for installation and assembly. Construction method.