JP2530865Y2 - Pedestal structure of reactor pressure vessel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pedestal structure for supporting a reactor pressure vessel in a reactor containment vessel.

[Prior Art] Conventional reactor vessels made of concrete include, for example,
As shown in FIG. 4, a reactor pressure vessel 2 is housed in a reactor containment vessel 1, and a cylindrical pedestal 3 (support seat) for supporting the pressure vessel 2 is provided upright. Also, between the pedestal 3 and the outer wall 4 of the containment vessel 1,
A diaphragm floor 5 that vertically partitions the inside of the reactor containment vessel 1 is bridged, a pressure suppression chamber 7 storing pool water 7a is formed below the diaphragm floor 5, and the reactor pressure vessel 2 is surrounded above the pressure suppression chamber 7. The upper dry well 6 is formed as described above. Further, a lower dry well 8 is formed in the pedestal 3.

The pedestal 3 is composed of a block body 9 having a configuration and a concrete wall 10 cast along the block body 9.
The block body 9 having the configuration includes a cylindrical body of an inner cylinder 11, an intermediate cylinder 12, and an outer cylinder 13 provided concentrically as shown
1, the intermediate cylinder 12, the outer cylinder 13 is formed with a number of vertical ribs 14 arranged in the circumferential direction, the inner cylinder 11, the intermediate cylinder 12, the Some of the communication holes 15 communicate from the upper dry well 6 to the lower dry well 8.
Are formed. In addition, a vent passage for guiding high-temperature and high-pressure steam leaking into the upper dry well 6 into the pool water 7a in the pressure suppression chamber 7 is provided in a part of the other holes.
16 are formed.

[Problem to be Solved by the Invention] In the above-described pedestal structure, in the communication hole 15, a pipe, a duct, and a ladder for lifting and lowering (all not shown) are provided from the upper dry well 6 to the lower dry well 8. Etc. are provided. These pipes, ladders, and the like are erected on a block body 9 having a structure, suspended from above by a crane or the like (not shown), inserted into the communication hole 15, and suspended in the air in the inner cylinder 11 or the intermediate cylinder. 12
It is designed to be installed in any of

However, since the communication hole 16 is a deep and narrow space, performing the installation work in a suspended state as described above in this space involves danger, and the mounting work is performed in an unstable state. However, there are disadvantages that the installation accuracy is deteriorated and that much time is required for installation.

Therefore, the present invention has been made in order to effectively solve these inconveniences, and an object of the present invention is to provide a new reactor pressure vessel in which piping, ducts and ladders of communication holes can be easily and safely attached. It provides a pedestal structure.

[Means for Solving the Problems] In order to solve the above problems, the present invention connects a cylindrical body in which a plurality of steel blocks of a pedestal supporting a reactor pressure vessel are concentrically arranged, and connects these cylindrical bodies. The steel block body is formed by sequentially welding the divided blocks obtained by dividing the steel block body into a lattice shape in the circumferential direction and the vertical direction, and a cylindrical body constituting each of the divided blocks. Some of the holes defined by the vertical ribs are used as communication holes for communicating the upper dry well on the outer periphery of the reactor pressure vessel with the lower dry well below the reactor pressure vessel, and the upper dry well is formed on the inner wall of the communication hole. A part of ducts and pipes extending from the well to the lower drywell side and a part of a ladder moving between the upper drywell and the lower drywell are incorporated in advance.

[Operation] As described above, the pedestal according to the present invention has a steel block body of the pedestal supporting the reactor pressure vessel as a divided block in which pipes and a part of a ladder are previously installed in a factory or the like. The installation work in the suspended state of the duct, the piping, and the ladder at the site can be omitted.

[Example] Next, an example of the present invention will be described with reference to the accompanying drawings.

1 to 3 show an embodiment of the pedestal structure of the reactor pressure vessel according to the present invention. In the drawing, the same reference numerals are given to the same parts as those in the conventional example, and the description will be omitted.

As shown in the figure, the pedestal 3 supporting the reactor pressure vessel 2 is composed of a cylindrical steel block body 9, and this block body 9 is further provided with a concentric inner cylinder 11, an intermediate cylinder It is formed by a cylindrical body of a cylinder 12, an outer cylinder 13, and a number of vertical ribs 14 arranged in the circumferential direction between the inner cylinder 11, the intermediate cylinder 12, and the outer cylinder 13. The inner cylinder 11 and the intermediate cylinder
Among the plurality of holes defined by the vertical ribs 12 and 12, a part of the holes is a communication hole 15 communicating from the upper dry well 6 to the lower dry well 8 described above. A pipe 17 leading from the upper dry well 6 to the lower dry well 8 and a ladder 18 for raising and lowering are provided.

The steel block body 9 is divided into a plurality of blocks 19 that are divided in a grid shape in the circumferential direction and the vertical direction (two-dot chain lines A, B, C, and D indicate dividing lines in the figure). Has become
Each of these divided blocks 19 is sequentially stacked in a cylindrical shape in the reactor containment vessel 1 and joined to each other to be erected.

As shown in FIG. 3, pipes 17 and ladders 18 which are divided into the same length as the height of the divided block 19 are installed in the communication holes 15 of the divided blocks 19.

In order to assemble the steel block body 9 made of such steel, first, the steel block body 9 is divided into a lattice shape in the circumferential direction and the vertical direction (A, B, C, and D in FIGS. A plurality of divided blocks 19 (showing dividing lines) are manufactured in advance in a factory or the like. At this time, when manufacturing each of the divided blocks 19, the divided pipes 17 and the ladders 18 and the like are simultaneously assembled in the communication holes 15 formed in the divided blocks 19. Next, after transporting these divided blocks 19 to the site, they are sequentially stacked in the reactor containment vessel 1 and joined to form a tubular steel block 9. At the time of assembling the block body 9, if the divided pipes 17, ladders 18, etc., which are attached in advance in the respective divided blocks 19, are joined, the steel block body 9 is formed and at the same time, the communication holes 15 are formed.
The installation of the piping 17 and the ladder 18 located inside is completed.

As a result, installation work such as pipes 17 and ladders 18 can be installed at the factory where the split block 19 is manufactured, and only connected at the site, so that the installation work can be performed safely and securely, and the installation accuracy is greatly improved. Can be improved.

[Effects of the Invention] In summary, according to the present invention, it is possible to omit installation work in a suspended state at the site of ducts, pipes and ladders provided in the communication holes of the steel block body, so that safety at the time of installation can be reduced. This greatly improves the installation accuracy of ducts, piping, and ladders, and provides a highly reliable pedestal.

[Brief description of the drawings]

1 is a partial sectional view of a pedestal showing one embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a perspective view showing a part of a divided block having a communication hole. FIG. 4 is a schematic overall sectional view showing the containment vessel. In the figure, reference numeral 2 denotes a reactor pressure vessel, 3 denotes a pedestal, 6 denotes an upper dry well, 8 denotes a lower dry well, 9 denotes a steel block, and 11, 12, and 13 denote inner and intermediate cylinders, respectively. Outer cylinder, 14 is a vertical rib, 15 is a communication hole, 17 is a pipe, 18 is a ladder, 19
Is a divided block.

Claims (1)

(57) [Scope of request for utility model registration] 1. A steel block for a pedestal supporting a reactor pressure vessel, comprising a plurality of concentrically arranged cylinders and a plurality of longitudinal ribs connecting between the cylinders. Are formed by sequentially welding the divided blocks divided in a grid shape in the circumferential direction and the vertical direction, and a part of the hole defined by the cylindrical body and the vertical rib constituting each of the divided blocks is formed in the reactor pressure vessel. A part of ducts and pipes extending from the upper dry well to the lower dry well side is formed on the inner wall of the communication hole, with a communication hole communicating the upper dry well on the outer periphery and the lower dry well below the reactor pressure vessel. A pedestal structure for a reactor pressure vessel, wherein a part of a ladder that moves between the upper drywell and the lower drywell is incorporated in advance.