JPS6144400A - Method of overhauling concrete structure - 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 [Field of Industrial Application] The present invention relates to a demolition method for dismantling a cylindrical concrete structure housing a nuclear reactor.

[Prior art]

When demolishing a concrete structure housing a nuclear reactor,
Do not spread radioactivity, reduce V-explosion, #
Care must be taken to reduce waste. By the way, conventionally known methods for dismantling concrete structures include blasting methods, mechanical methods using impact and hydraulic pressure, and thermal methods using flame and electrical heating. Various problems arise when dismantling concrete structures that house housing objects. In other words, in the blasting method and mechanical construction method using base and hydraulic pressure, radioactively contaminated concrete becomes fragments and dust and spreads around the surrounding area (
Problems such as scattering and dispersion of radioactivity may occur, and if large-diameter reinforcing bars are used in the concrete structure to be demolished, it is difficult to cut these large-diameter reinforcing bars. A crack may occur during this period. In addition, in the thermal construction method, a problem arises in that primary waste from the flue is generated in large amounts.〇 [Object of the Invention] The present invention was made in view of the above circumstances Vc6, and it prevents the spread of radioactivity and To provide a method for dismantling a concrete structure that can simultaneously cut large-diameter reinforcing bars, reduce exposure to radiation, and minimize the generation of secondary waste such as smoke.

[Structure of the invention]

In order to achieve such an object, the present invention uses a core drill to continuously drill holes in the center part of the cylindrical wall in the thickness direction in the circumferential direction to cut the inner part of the wall from the outer part, and a diamond cutter to cut the inner part of the wall from the outer part. The method used is to cut the inner part of the wall in a lattice pattern to divide the inner part of the wall into blocks, and then remove and dismantle the divided small block pieces one by one.

[Action of the invention]

The inner part of the wall contaminated by radioactivity can be dismantled while leaving the outer part of the wall intact, and large-diameter reinforcing bars can be cut at the same time.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to one page. 1st
The figure is a diagram explaining the procedure of the method of the present invention, and FIG. 2 is a diagram showing a cylindrical concrete structure for containing a nuclear reactor that is dismantled by the above-mentioned method.

In dismantling the concrete structure A, first: 1) As shown in Figure 1, the central part of the cylindrical wall W in the thickness direction is continuously drilled in the circumferential direction using a core drill (not shown); Inner part W1 contaminated by radioactivity and outer part W not contaminated by radioactivity! sever ties with. Since a large number of holes 1 are connected to each other and the edges are cut in this way, even if the wall W is curved at any curvature, the same wall W can be divided into an inner part W and an outer part W.
, and can be easily cut off.

11) Next, the core 2 produced when the wall W is bored is taken out, stored in a radioactivity-proof container 3 prepared in advance, and transported outside.

(2) Next, cut grooves 4 extending vertically in the inner portions W and K of the wall W are cut using a diamond cutter (not shown).

1v) A cut groove 5 extending horizontally in the inner portion W1 of the wall W from a countersunk or diamond cutter (not shown) K
into the inner part W1 of the wall W with a plurality of small block pieces 6
Divide into.

Note that the above operations 11) to +V) do not necessarily have to be performed in this order; for example, operations 1ii) and IV) may be performed first, followed by operations 11), or ii+) and IV). ) may be performed in reverse.

(2) Next, the divided small block pieces 6 are stored in a radioactive container 7 prepared in advance and transported outside.

When the wall W is cut with a core drill or a diamond cutter, cooling water is poured into the 16 cut locations, and this cooling water is collected at any time, filtered, and used later. When the cutting operation is completed, the cooling water is collected into a container and transported outside.

In addition, chips C are generated during the above-mentioned cutting operation, but these chips C are collected by the collection bag r1i8 when the cutting operation is interrupted or when the cutting operation is completed, and then placed in the container 9 and transported to the outside. Ru.

All of the above chrysanthemum planting is done by remote control.

vl) After dismantling the inner wall portion W, contaminated by radioactivity in this way, the outer wall portion W! is dismantled by a conventional dismantling method, such as the mechanical method and isopressure described in the above-mentioned prior art.

〔Effect of the invention〕

As explained above, according to the present invention, the inner part of the wall contaminated with radioactivity can be dismantled with some of the outer parts remaining, and therefore the concrete contaminated with radioactivity can be broken into pieces. This prevents radioactivity from scattering outside in the form of dust particles, preventing the spread of radioactivity, and reducing the exposure to f: 11. The amount can be kept to a minimum. In addition, the only secondary waste is the cooling water poured into the cutting part of the cutter or drill, and this cooling water can be quickly recovered, which also prevents the spread of radioactivity and reduces the 4i! Can be pressed with less force.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining the procedure of the present start-up method, and FIG. 2 is a perspective view of an inner cylindrical concrete structure for containing a nuclear reactor that is dismantled by the above procedure. A... Concrete structure pickles, W... Wall, Wl... Inner part of wall, Wl...
・Outer part of the wall, 1... hole, 2...
Core, 3,7...Radioactive container, 4.5
... Cut groove, 6 ... Small block piece, C.
...chips.

Claims (1)

[Claims] A method of dismantling a cylindrical concrete structure housing a nuclear reactor, in which a core drill is used to continuously drill holes in the center part of the cylindrical wall in the thickness direction in the circumferential direction. In addition to cutting the edges from the outer part of the body, the inner part of the wall is cut in a grid pattern using a diamond cutter to divide the inner part of the wall into blocks, and these divided small block pieces are sequentially removed and dismantled. A method for dismantling a concrete structure characterized by: