JPH0572996B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for dismantling a concrete heat shielding wall of a nuclear reactor.

(Prior art) When dismantling a nuclear reactor, or dismantling the so-called radioactively contaminated concrete heat shield wall (hereinafter referred to as the reactor wall), it is necessary to completely protect human bodies and the atmosphere from radioactive contamination. It must be dismantled and removed.

That is, it is necessary to accurately cut the furnace wall, mechanically grip the cut furnace wall block, and safely transport it. For this reason, recently, mechanical devices such as longitudinal and transverse cutting machines and gripping machines are installed on the same main shaft installed vertically in the reactor body, and methods and equipment have been developed in which these mechanical devices are operated centered on the main shaft. is proposed.

(Problem to be solved by the invention) However, in the above demolition method and equipment, mechanical devices such as vertical and horizontal cutting machines and gripping machines are installed on one main shaft, so if the furnace diameter is small, multiple The problem was that it was not possible to operate two mechanical devices simultaneously and smoothly.

(Means for Solving the Problems) The dismantling method of the present invention was devised to solve the above problems, and involves moving the main shaft eccentrically from the gantry frame swivel base at the top of the reactor into the cavity. A horizontal cutting machine is fixed to the lower part of the main shaft, and after cutting the furnace wall horizontally, a vertical cutting machine is introduced into the main shaft and lowered. After cutting the back side, it is raised to release the main shaft, and then the main shaft is rotated by the swivel table, and the gripping machine is introduced into the main shaft and lowered, gripping the cut furnace wall block. The furnace wall block is lifted up by the gantry frame, and the furnace wall block is carried out to the outside of the gantry frame via a carrying-out device.

Further, the dismantling apparatus of the present invention includes a gantry frame provided at the upper part of the reactor, a main shaft eccentrically suspended in the cavity from a swivel table arranged on the gantry frame, and a main shaft fixed in advance to the lower part. It consists of a horizontal cutting machine, which is stored in the upper part of the gantry frame, and a vertical cutting machine and a gripping machine, which are alternately introduced into the main shaft and raised and lowered. A mechanical device is remotely controlled, and the furnace wall block can be smoothly cut to a predetermined size and thickness by mechanical operation, and the furnace wall block is also carried out in a completely sealed state.

As a result, the efficiency of demolition work is significantly improved, and safety and air pollution can be reliably prevented.

(Example) The nuclear reactor dismantling method and apparatus of the present invention will be specifically explained below based on the drawings.

FIG. 1 is a schematic front view illustrating a nuclear reactor dismantling device.

The nuclear reactor dismantling apparatus of the present invention has a gantry frame 1 installed in a shielding building 10 provided at the top of a nuclear reactor 1.
1 is an enclosure, a lifting device 12 is provided above the enclosure, and a main shaft 20 is vertically installed in a cavity 14 via the lifting device 12.

Further, a swivel table 13 is provided at the lower part of the elevating device 12, and the main shaft 20 is rotated by this swivel table 13. Further, as shown in FIG. 2, which is a plan view taken along the line A--A in FIG. 1, the main shaft 20 is vertically installed eccentrically with respect to the central axis of the cavity 14. However, the swivel base 13 is formed to rotate around the cavity 14 around the central axis. A transverse cutter 30 is fixed to the lower part of the main shaft 20. This transverse cutting machine 30 has a structure in which it can rotate horizontally around the main shaft 20 and can vary its angle in the vertical direction. On the other hand, the other mechanical devices, a vertical cutting machine 40 and a gripping machine 50, are stored in the upper part of the gantry frame 11 so as to face each other with the swivel table 13 at the center.
Furthermore, a carry-out machine 60 is provided at the upper part of the gantry frame 11, and a locking device 70 is provided on one side wall of the gantry frame 11. The container 71 containing the cut furnace wall blocks is carried into the locking device 70 via the transfer device 72, the lid of the container 71 is closed by the opening/closing device, the radioactivity is decontaminated by the decontamination device 73, and the container is moved to the elevator. It is transferred by a device 80 and taken out of the shielding building 10.

FIG. 3 is a schematic side view illustrating the cross-cutting machine 30 fixed to the lower part of the main shaft 20.

An outrigger O provided at the lower end of the main shaft 20 is stretched between the furnace walls, and a transverse cutter 30 cuts the furnace walls. The horizontal cutting machine 30 is a burning bar 3
1 is held by a holder 32 and cut into horizontal slices by combustion and injection.

When the burning bar 31 is consumed by combustion, a new burning bar 31 is replenished from the burning burst stocker S ₁ to enable continuous cutting.

FIG. 4 is a schematic side view illustrating the operation of the vertical cutting machine 40 and the gripping machine 50.

As described above, the main shaft 20 is vertically installed through the lifting device 12 and the turning table 13 provided on the upper part of the gantry frame 11, and the vertical cutting machine 40, the gripping machine 50, and the Unloading machines 60 are respectively stored and arranged. The vertical cutting machine 40 and the gripping machine 50 are both suspended by a wire R via a sheave block CR provided at the upper part of the main body. Moreover, the slide base SB installed inside the upper side of the gantry frame 11
The winch W is wound around the wire R to keep it in tension, and the center cylinder CP is held by a reaction force. Further, the slide base SB is moved horizontally within the upper surface of the gantry frame 11 by the slide cylinder SC.

FIG. 5 is a plan view taken along the line B--B in FIG. 4.

As can be seen from this plan view, the vertical cutting machine 40 and the gripping machine 50 are housed in a state facing each other with the swivel base 13 as the center, while the main shaft 20 is located on the swivel base 1.
Since the main shaft 20 is vertically installed eccentrically from the center of the main shaft 3, when the swivel table 13 is rotated, the main shaft 20 comes close to either the vertical cutting machine 40 or the gripping machine 50. As will be described later, in this close state, the vertical cutting machine 40 or the gripping machine 50 is mounted on the main shaft 20 and introduced.

Next, the structure and operation of the vertical cutting machine 40 will be explained with reference to FIGS. 6 to 9.

FIG. 6 is a schematic side view illustrating the structure of the vertical cutting machine 40.

The vertical cutting machine 40 holds a burning bar 44 via a holder 43 attached to the tip of an operating arm 42 attached to a main body 41, and temporarily horizontally moves the burning bar 44 by driving a slide box 45. 4.
6 to adjust the vertical angle. Furthermore, it is secondarily moved in the horizontal direction by a drive motor 47.
It can turn around the main shaft 20.

On the other hand, as described above, the vertical cutting machine 40 itself is held on the slide base SB by the reaction force of the center cylinder CP via the wire R provided with the sheave block CR on the upper part of the main body 41.

FIGS. 7 and 8 are schematic side and plan views illustrating the state in which the main shaft 20 is mounted.

That is, the mounting parts 48, 48 provided substantially above and below the main body 41 include a fixed mounting piece 48a, a movable mounting piece 48b, 48c, and a movable mounting piece 48b, 4.
It is formed by cylinders 48d and 48e that open and close 8c. The fixed mounting piece 48a is a curved piece whose inner diameter is approximately equal to the outer diameter of the main shaft 20,
On the other hand, the movable mounting pieces 48b and 48c are also curved pieces having the same diameter as the main shaft 20. Therefore, when these fixed mounting pieces 48a and movable mounting pieces 48b and 48c are closed, a hollow space having the same diameter as the main shaft 20 is formed. The movable mounting pieces 48b and 48c are set in the open state (dotted line state in FIG. 8) by the respective cylinders 48d and 48e, and the fixed mounting piece 4 is fixed to one side of the main shaft 20 by operating the slide base SB.
8a is in contact with the cylinder 48.
The movable mounting pieces 48b and 48 are driven by d and 48e.
c is closed and brought into contact with the other side of the main shaft 20.

Therefore, the vertical cutting machine 40 is installed on the main shaft 20 and introduced. On the other hand, to release the vertical cutter 40 from the main shaft 20, drive the cylinders 48d and 48e to open the movable mounting pieces 48b and 48b, and move the slide base SB back to the main shaft 20. The attachment is released by moving away from the shaft 20.

As described above, FIG. 9 shows that the vertical cutting machine 40 is lowered to a predetermined position with the main shaft 20 introduced, and the operating arm 4 is moved by the slide box 45.
2 is expanded and contracted to a predetermined length, and the holder 43 is held at a predetermined angle by an elevating cylinder 46, and the back side of the furnace wall is cut by combustion injection from a burning bar 44. A burning burst stocker _S2 is provided for replenishing new burning bars 44 when the burning bars 44 are consumed by combustion.

10 and 11 are side and plan schematic views illustrating the structure of the gripper 50. FIG.

The gripping machine 50 is provided with a rotating motor M ₁ at the tip of an arm 52 that extends and retracts from a slide cylinder 51, and a gripping arm 55 is provided via an elevating cylinder 54 by a shaft 53 hanging from the rotating motor M ₁ . The gripping arm 55 is rotated by the shaft 53 by a rotating motor _M1 provided at the tip of the arm 52.
Rotate around. Further, the angle of the gripping arm 55 with respect to the horizontal direction is adjusted by the elevation cylinder 54. Furthermore, the gripping arm 55 is rotated by the rotation motor _M2.
The structure is such that the main shaft 20 rotates around the main shaft 20. This gripping machine 50 also has the above-mentioned vertical cutting machine 4.
0, the upper part of the main body is held on the slide base SB by the sheave block CR, wire R and center cylinder CP. Moreover, as shown in FIG. 11, the fixed mounting piece 57a and the movable mounting piece 57b,
7c to be attached to the main shaft 20 and introduced, and released from the introduction by release.

Next, the process of cutting the furnace wall will be explained.

First, as shown in FIG. 12a, the main shaft 20 is placed in a predetermined position using the lifting device 12, and the outrigger O is stretched within the furnace wall. Then, the horizontal cutter 30 is placed at a predetermined position, and the burning bar 31 is burned to perform horizontal cutting. The cutting is usually done in a round shape perpendicular to the central axis of the furnace wall. When a predetermined amount of cutting is completed, the burning bars 31, 31 in the burning burst stocker _S1 are consumed and become empty, and it is necessary to replace them with a new burning burst stocker _S1 brought in via the locking device 70. For this purpose, the gripper 50 is introduced into the main shaft 20 and raised and lowered, and the new and old burning burst grips S ₁ and S ₁ of the cross-cutting machine 30 are replaced (FIGS. 12b and 12c). When this replacement work is completed, the gripper 50 is held on the slide base SB by the tension of the wire R by the winch W and the reaction force of the center cylinder CP. Next, the movable gripping piece 57 is moved by the cylinders 57d and 57e.
b and 57c are opened, and the slide base SB is moved and stored in a desired position by driving the slide cylinder SC (FIGS. 4 and 11).

When the gripping machines 50 are retracted, the vertical cutting machines 40 are introduced into the main shaft 20 alternately with the gripping machines 50 and lowered to a predetermined position. The vertical cutter 40 continuously cuts the back side of the furnace wall cut into circular slices. The cutting is performed by burning and injecting the burning bar 44 as described above (FIG. 13a). When the predetermined amount of backside cutting is completed, the burning bars 44, 44 in the burning burst cutter S ₂ are cut in the same way as in the case of the transverse cutting machine 30.
will be consumed and empty, so you will have to replace it with the new Burning Burst Tsuka S ₂ . For this purpose, the vertical cutting machine 40 itself is raised, and the new burning burst stocker _S2 is gripped and replaced by the gripper 50 stored in the upper part of the gantry frame 11 (FIG. 13b). When the back side of the furnace wall is continuously cut, the vertical cutter 40 is pulled up in the same way as the above-mentioned gripper 50, released from the main shaft 20, and stored at a predetermined position in the upper part of the gantry frame 11. Next, it is cut into furnace wall blocks at predetermined intervals by a transverse cutting machine 30, and then cut into furnace wall blocks by a gripping machine 5 again.
0 is introduced into the main shaft 20 and arranged in the state shown in FIG. 14a, the furnace wall block is gripped by the gripping arm 56 (FIG. 14b), and the furnace wall block is lifted into the container 71 placed in advance. Insert the block (Figure 14c). Once a predetermined amount of furnace wall blocks have been stored, the container 71 undergoes a predetermined treatment within the lock device 70, as described above, is transferred into the elevator device 80, and is carried out of the shielding building 10.

(Effects of the Invention) As explained above, in the demolition method and device of the present invention, a horizontal cutting machine is fixed to the lower part of the main shaft, and mechanical devices such as a vertical cutting machine and a gripping machine are alternately attached to the main shaft. Because of this, even when dismantling a reactor with a small reactor diameter, processes such as horizontal and vertical cutting, replacement of burning burst stockers, and removal of reactor wall blocks can be performed automatically and mechanically, resulting in efficient dismantling. becomes possible. Moreover, since the reactor wall block itself is transported completely sealed, there is no contamination to the outside world such as human bodies or the atmosphere, making this a very suitable method and device for dismantling a nuclear reactor.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view illustrating a nuclear reactor disassembly apparatus according to the present invention, and FIG.
- A plan view taken along line A; FIG. 3 is a schematic side view illustrating the horizontal cutting machine; FIG. 4 is a schematic side view illustrating the vertical cutting machine and gripping machine; At B
- A plan view taken along line B, FIG. 6 is a schematic side view illustrating the structure of the vertical cutting machine, FIG. 7 is a schematic side view illustrating the installed state of the vertical cutting machine, and FIG. 8 is the same plane. Schematic diagrams; FIG. 9 is a schematic side view illustrating cutting of the back surface of the furnace wall by a vertical cutting machine; FIG. 10 is a schematic side view illustrating the structure of the gripping machine; FIG. 11 is a schematic plan view of the same; FIGS. 12a, b, and c are schematic side views illustrating the process of cutting the furnace wall; FIGS. 13a and b are schematic side views illustrating the state in which the cutting machine is raised and the burning burst stocker is replaced; Figure 14 a, b, c
FIG. 2 is a schematic side view illustrating a state in which a furnace wall block is gripped and carried out by a gripper. 1... Nuclear reactor, 10... Shielding building, 11...
Gantry frame, 13... Swivel base, 14...
Cavity, 20... Main shaft, 30...
Horizontal cutting machine, 40...vertical cutting machine, 50...gripping machine.

Claims (1)

[Scope of Claims] 1. A main shaft is vertically eccentrically placed into the cavity from a rotating base of a gantry frame provided at the upper part of the reactor, and the reactor wall is cut horizontally by a transverse cutter fixed to the lower part of the main shaft. After cutting, a vertical cutting machine is introduced into the main shaft and lowered, and after vertical cutting, it is raised and released from the main shaft, and at the same time, the swivel table is rotated and a gripping machine is introduced into the main shaft and lowered. A method for dismantling a nuclear reactor, characterized in that the cut reactor wall block is gripped by the gripper, raised, and transported to the outside of the gantry frame via a carry-in/out device. 2. A gantry frame installed in the upper part of the reactor, a main shaft hanging eccentrically from the swivel base of the gantry frame into the cavity, a transverse cutting machine fixed to the lower part of the main shaft, and a gantry frame installed in the upper part of the gantry frame. A nuclear reactor dismantling device consisting of a vertical cutting machine and a gripping machine that are housed and introduced into the main shaft alternately.