JPH07111478B2 - Cutting and demolition method for cylindrical structures - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for cutting and dismantling a cylindrical structure such as a heat shield wall (RSW) of a boiling cooking (BWR) nuclear power plant.

[Technical background and prior art] The major difference between the dismantling of such concrete structures and the dismantling of general structures is that they have been activated (change to new radioactive materials) and that they are contaminated with the activated materials. And the fact that there are many assimilar concrete structures with a large amount of reinforcing bars as a whole.

For this reason, since the worker cannot access the activated part, it is necessary to perform a dismantling process by remote control and to prevent scattered dismantled fragments and dust from scattering.

A technique of cutting into a cylindrical shape, a structure and a ring shape is disclosed in, for example, Japanese Patent Application Laid-Open No. 56-111763. However, in such a known technique, a special device is attached to a position to cut the cylindrical structure to be cut, and the cutting work is sequentially performed, which is troublesome and requires a scaffold, etc. Not suitable for cutting contaminants.

Further, in Japanese Patent Laid-Open No. 60-44898, a main shaft is erected at the center of a cylindrical structure to be cut, and the plasma cutting device is moved by using the main shaft, and a U-shape with an open upper side. A technique is disclosed in which a cylindrical structure is cut into a shape, and the cut block is grasped by a gripping device and taken out. In such a known technique, standing of the main shaft and grasping of the cut block are troublesome, resulting in poor work efficiency.

[Problem to be Solved by the Invention] Therefore, an object of the present invention is to provide a method for cutting and dismantling a cylindrical structure, which is easy to work, suitable for automation, and has improved work efficiency.

[Means for Solving the Problem] According to the present invention, in a method for cutting and dismantling a cylindrical structure provided in a building by cutting and dismantling the cylindrical structure from the inner wall side, a plurality of holding members provided radially are provided. A cutting device having a ring-shaped frame having a cylinder and a jet nozzle movably provided along the ring-shaped frame is prepared, and the cutting device is hung by a crane and positioned inside the cylindrical structure. , The holding cylinder is extended, the cutting device is fixed inside the cylindrical structure, the jet nozzle is moved along the frame to cut the cylindrical structure into a ring shape, and the cut ring-shaped primary block is cut. While being held by the equipment, it is lifted by a crane and carried out to the dismantling room in the building.In the dismantling room, the ring-shaped primary block is cut in the cylindrical direction, and each cut secondary A lifting hole is formed in the block, and the secondary block is grasped by a crane using the lifting hole and stored in a container.

[Explanation of action and effect] Therefore, if the cutting device is fixed to the inside of the cylindrical structure, the jet nozzle can move reliably along the ring-shaped frame, and as a result, the cylindrical structure can be moved from the inside to the ring-shaped structure. Can be cut as a primary block. The cut primary block can be carried out to the dismantling room by a crane while being fixed to the cutting device, and the carrying out work is easy.

Since the dismantling room is provided inside the building, it is easy to carry it out to the dismantling room. In the dismantling room, the ring-shaped primary block is cut into small blocks to form a secondary block, and holes are drilled.When lifting the secondary block, use a jig that penetrates the hole to ensure that it is lifted by a crane. It can be performed. In the work in the dismantling chamber, since the ring-shaped primary block is installed so that its axis line is vertical, the cutting and drilling work can be easily performed in the installed state.

Since the work of lifting the secondary block is easy, the work of storing it in the container is also easy.

As described above, in the present invention, since the cylindrical structure is cut into the ring-shaped primary block and then cut into the sub-divided secondary blocks, automation is easy, and when disassembling contaminants such as RSW, the human body Does not pose a risk to

[Preferred Embodiment] In carrying out the present invention, it is preferable to use a treatment apparatus for slurry and exhaust gas. By doing so, it is possible to prevent the scattered dismantled pieces and dust from scattering.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a case where the cutting and disassembling method of the present invention is applied to a heat shield wall (hereinafter referred to as RSW) 1 of a BWR type nuclear power plant, for example.

In the figure, RSW1 has a diameter of about 10 m, a height of about 15 m, and a thickness of about 60 cm.
This is a cylindrical steel structure consisting of inner and outer surface shells made of thick steel plate with a thickness of about 30-45 cm and a partition plate between the shells, filled with concrete or mortar, and covered with a biological shielding wall (BSW) 2. It is stored in the Reactor Containment Vessel (PCV) 3.

A cutting and disassembling apparatus using an abrasive jet embodying the present invention includes a cutting apparatus 10 set at a cutting portion of a BSW1, an abrasive jet apparatus 20, a slurry processing apparatus 30, an exhaust processing apparatus 40, and a secondary block. It consists of a dismantling room 50, and the existing crane 5 in the building 4 is used as a lifting treatment device.

2 and 3, the cutting device 10 includes a ring-shaped frame 12 held on the inner wall of the RSW 1 by holding cylinders 11, 11, ..., And a rotation motor on the lower surface of the frame 12.
A guide plate 14 rotatably supported via 13,
A circular arc-shaped soundproof / water-leaking cover 16 movably supported in the guide plate 14 via a nozzle pressing cylinder 15 in a radial direction, a nozzle holder 17a for holding a jet nozzle 17 provided in the cover 16, and a nozzle. Cover holder 17a
Nozzle running motor 18 that runs along the inner wall of BSW1 in 16 and cutting back protective cover attached to the outer wall of BSW1
It consists of 19.

In FIG. 1, an abrasive jet device 20 includes an ultrahigh pressure pump 21, an abrasive tank 23, and a monitor control board 25. The ultrahigh pressure pump 21 is connected to a supply water source (not shown), is connected to a jet nozzle 17 via a high pressure water pipe 22, and the abrasive tank 23 is connected to a jet nozzle 17 via an abrasive pipe 24. The monitoring control board 25 includes the abrasive jet device 20, and controls the entire cutting and disassembling device by remote control.

The slurry processing device 30 includes a pump 32 connected to the cutting rear side protective cover 19 via a slurry discharge pipe 31, a magnetic separator 33 provided on the downstream side of the pump 32, and an abrasive material separated by the magnetic separator 33. Abrasive receiving material 34, raw water tank 35 for receiving water from magnetic separator 33, raw water pump 36, coagulation reaction tank 37 connected to raw water tank 35 via raw water pipe 36a, and downstream side of coagulation reaction tank 37 A settling tank 38, a sludge receiver 38a for receiving sludge separated by the settling tank 38, and a treated water tank 39 for receiving water from the settling tank 38.

The exhaust treatment device 40 includes a cooling heat exchanger 43 connected to a steel lid 41 that covers the upper end opening of the RSW1 via an exhaust pipe 42, and a mist eliminator that is sequentially provided on the downstream side of the heat exchanger 43. Noeta
44, an electric heater type heater 45, a filter 46 and a turbo blower 47, and the heat exchanger 43 and the mist eliminator 44 are connected to the slurry discharge pipe of the slurry processing apparatus 30 via a pipe 48.
31, the turbo blower 47 is connected to an existing exhaust treatment facility (not shown).

The secondary block dismantling chamber 50 is provided in the building 4, is provided with an abrasive jet cutting device 51, a crane 52, and a container 53 for housing the secondary block 1B is prepared.

Next, an embodiment of the present invention will be described.

First, the crane 5 suspends the cutting device 10 with the wire 6 from the upper opening of the RSW 1 to a predetermined depth, and the holding cylinder
11 is extended to hold the cutting device 10 on the inner wall of the RSW 1. The cutting device 10 is supported by a steel lid 41, and the steel lid 41
May be hung by the wire 6.

Next, the wire 6 is removed, the steel lid 41 is set, and the cut back side protective cover 19 is set at a position facing the soundproof / leakage cover 16 on the outer wall of the RSW 1.

Next, the abrasive jet device 20, the slurry treatment device 30, and the exhaust treatment device 40 are operated, the nozzle traveling motor 18 moves the nozzle 17, and the abrasive jet is used.
RSW1 is cut only within the range of the soundproof / leakage cover 16, and the rotating motor 13 rotates the soundproof / leakage cover 16 by the length of the cover 16 to repeat the cutting, and RSW1 has a height of, for example, 1.4. Cut into a ring-shaped primary block 1A of m. At this time, the slurry is processed by the slurry processing device 30, and the dust and gas are processed by the exhaust processing device 40.

Next, as shown in FIG. 4, the crane 4 lifts the primary block 1A with the wire 6 and the secondary block dismantling chamber 50.
To carry out.

In the dismantling chamber 50, the primary block 1A is cut into small pieces in the cylindrical direction, for example, to a length of 2.9 m by the abrasive jet cutting device 51 (Fig. 5) to form the secondary block 1B and the lifting holes. Drill 1c (Fig. 6). Then the hole
The secondary block 1B is grabbed by the crane 52 via the 1c (Fig. 7), lifted (Fig. 8), and stored in the container 53 (Fig. 9).

[Effects of the Invention] As described above, the present invention has the following excellent effects.

(I) Since the primary block can be lifted as it is in a cut state, it is easy to carry out.

(Ii) Since the dismantling room is provided indoors, the primary block can be transported directly to the dismantling room by a crane.

(Iii) The primary block can be easily hung in the dismantling room by simply hanging the primary block in the dismantling room.

(Iv) By making a hole in the secondary block, it is possible to reliably carry out with a crane.

(V) Therefore, automation is easy, there is no danger to the human body when disassembling pollutants, and work efficiency is improved.

[Brief description of drawings]

1 is an overall configuration diagram of an apparatus for carrying out the present invention, FIG. 2 is a perspective view showing a cutting apparatus, FIG. 3 is a radial sectional view of FIG. 2, and FIG. 4 shows a state in which a cutting block is lifted. The perspective views, FIG. 5, FIG. 6, FIG. 7, FIG. 8 and FIG. 9 are perspective views showing the step of cutting the secondary blocks into small pieces. 1 ... Heat shield wall (RSW), 1A ... Primary block, 2B ...
Secondary block, 10 ... Cutting device, 16 ... Soundproof / leakage cover, 17 ... Jet nozzle, 19 ... Cutting back protective cover, 20 ... Abrasive jet device, 30 ... Slurry processing device, 40 ... … Exhaust treatment device, 50 …… Secondary block dismantling room

Front Page Continuation (72) Kenjiro Nakamura Inventor Kenjiro Akasaka 1-2-7, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) Reference JP-A-56-111763 (JP, A) JP-A-60-44898 ( JP, A)

Claims (1)

[Claims] 1. A ring-shaped frame having a plurality of radially-arranging holding cylinders and its ring in a method for cutting and dismantling a cylindrical structure provided in a building by cutting and dismantling the cylindrical structure from the inner wall side. A cutting device having a jet nozzle movably provided along a circular frame, suspending the cutting device with a crane and positioning it inside a cylindrical structure, and extending a holding cylinder to cut the cutting device. Is fixed inside the cylindrical structure, the jet nozzle is moved along the frame to cut the cylindrical structure into a ring, and the cut ring-shaped primary block is held by a cutting device and lifted by a crane. The ring-shaped primary block in the dismantling room in the direction of the cylinder in the dismantling room, and a lifting hole is drilled in each of the cut secondary blocks. Cutting demolishing method cylindrical structure, characterized in that accommodated in the container by grasping the secondary block by a crane with a lifting hole of.