JPS6186696A - Recovery device for falling slag - 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 (Technical Field) The present invention relates to a falling slag recovery device for recovering fallen slag generated at the bottom of a reactor when the inner wall of a nuclear reactor is cut.

(Technical background) To dismantle a nuclear reactor, the radioactively contaminated inner concrete walls must be dismantled and removed while safely isolating them to prevent contamination of human bodies or the atmosphere.

Therefore, in order to cut the inner concrete wall, cutting with a burning bar is carried out safely and efficiently using remote control, and the demolition blocks created by the cutting are also removed and removed while being completely isolated from the human body and the atmosphere. There is a need.

On the other hand, in addition to the cutting blocks, fine slag is produced as a by-product when cutting with an eight-ring parr. This slag is also contaminated with radioactivity, so like the cutting blocks, it must be transported and removed in a completely isolated state.

Furthermore, since this slag scatters and falls during cutting, it must be appropriately collected at the bottom of the furnace and the collected fallen slag must be recovered.

(Object of the Invention) The present invention has been made in view of the above points, and is a method for safely collecting and recovering slag generated when cutting the inner wall of a nuclear reactor, the so-called concrete heat shield wall, by remote control. The present invention provides a device for collecting fallen slag to be carried out and removed.

(Summary of the Invention) The fallen slag recovery device of the present invention forms a slag receiving tank by providing a (↑, )-shaped side wall on a rotary table placed at the bottom of a nuclear reactor. A weir plate is installed in this receiving tank, and a crushing beam is installed at the top of the slag receiving tank to crush the falling slag, which falls to the bottom of the reactor by this recovery device. The system collects and transports fine slag safely and efficiently using remote control.

(Example) Hereinafter, a fallen slag recovery device of the present invention will be explained with reference to the drawings.

FIG. 1 is a partially cutaway perspective view illustrating the dismantling work of a nuclear reactor. To outline the nuclear reactor dismantling work, an enclosure IO is built over the head 1a of the reactor 1 to shield the inside of the reactor from the outside. And the upper side 11 of this enclosure lO
A gantry 20 and a lifting device 30 are installed in the furnace, and a main shaft 40 is suspended in the furnace through these.

A cutting device 50 is provided at the lower end of the main shaft 40, and the gantry 20. The elevator 30 and the main shaft 40 act as a supporting drive for the cutting device 50 .

That is, as the elevating device 30 traverses, ascends and descends, and rotates, the cutting device 50 moves in the horizontal direction and direction via the main shaft 40.
- Move downwards and rotate horizontally. This cutting device 50 is provided with a cutting machine that injects and burns fuel by burning/burning to perforate holes, and the inner wall of the nuclear reactor 1 is cut into a block shape by this cutting machine. The cut block cut by the cutting device 50 is gripped by a gripping device 60 that moves up and down using the main shaft 40 as a guide, and is carried out to the outside via a conveyance device of a carry-in/out lock cuff 0 provided in the enclosure IO. .

As described above, when the inner wall is cut by the cutting device 50, molten slag is generated during injection combustion of the burning par, which falls to the furnace bottom 1b and scatters.

A slag recovery device 80 is arranged at the hearth bottom 1b. The slag that has fallen into the slag collection device 80 is collected as will be described later, and is dropped by the bucket device 81 into a storage container of the unloading device 70, and the container is sealed and transported outside.

2 to 4 are for explaining the slag recovery device 8o, FIG. 2 is an explanatory view taken along the line A-A in FIG. 1, FIG. 3 is an explanatory view taken along the line B-B in FIG. FIG. 4 is an explanatory diagram taken along the line C--C in FIG. 3. - To further explain the slag recovery device 80 based on these explanatory diagrams, a rotary table 82 is provided at the hearth bottom 1b. The rotary table 82 has a disk shape with a size approximately equal to the diameter of the hearth bottom 1b. This rotary table 82 is rotated in a fixed direction approximately around the reactor core by, for example, two rotary motors M and H.

Further, a cylindrical side wall 83 is arranged on the upper surface 82a of the rotary table along the inner circumference of the furnace bottom 1b. That is, the rotary table 82 and the cylindrical side wall 83 placed on its upper surface 82a form a circular tank, a so-called slag receiving tank 84. In addition, in this slug receiver -84, the one-turn table 82 and the cylindrical side wall 83 must not be fixed integrally.

On the other hand, a weir plate 85 is attached to a rotary table 82 in a slag receiving tank 84.
It is arranged so as to have a constant angle with respect to the rotation direction (arrow direction in FIG. 2). This weir plate 85 is not fixed to the rotary table 82, that is, when the rotary table 82 rotates, the weir plate 85 scrapes the slag that has fallen onto the upper surface 82a of the rotary table and collects it at a predetermined location in front of it.

A crushing beam 86 is provided at the upper part of the receiving tank 84, and this crushing beam 86 includes an annular outer ring beam 86a along the inner periphery of the furnace shape;
Furthermore, it consists of an inner ring beam 88b with a small diameter, and a beam 8Bc connecting the side beams.
It is connected with 88c... So-called ridge-like acute angle portions are formed on the upper surfaces of these beams, and when falling slag collides with the crushing beam 86, the ridge-like acute angle portion breaks the slag into fine pieces. Also, in order to carry out the slag collected in front of the weir plate 85, a bucket 81 is thrown in from above. Therefore, the crushing beam 8 stretched above the receiving tank 84
It is necessary to form a bucket inlet 87 in a part of 8. The bucket 81 is lowered to a predetermined position in the slag receiving tank 84 by a winch W provided on the lower surface of the upper side 11 of the enclosure 10, as shown in FIG. A weir plate 85 is provided at a downstream position in the rotational direction of the rotary table 82 from that position, and a /hekent inlet 87 is provided at the front upper part of the weir plate 85 in the rotational direction.

The operation of collecting and transporting slag using the slag collecting device 80 having the second configuration will be described below.

The slag produced as a by-product by the cutting operation of the cutting device 50 collides with the crushing beam 86 as it falls through the furnace, is further crushed into fine pieces, and is scattered into the slag receiving tank 84 as fine slag. The slag falls almost uniformly onto the so-called table top surface 82a.

Then, when the rotary motors M and M are driven to rotate the rotary table 82 in the direction of the arrow in FIG.
The slag on the rotary table 82 is pushed forward by the weir plate 85 and is so-called scraped, and when the rotary table 82 rotates once, most of the slag on the upper surface 82a of the rotary table is collected in front of the weir plate 85. Next, the bucket 81 is lowered from the bucket input port 87 provided at the front upper part of the weir plate 85, and the bucket shell is opened to store the slag and carry it out. The slag carried out by the bucket 81 is dropped into the storage container of the carry-in/out lock device 70, and by sealing the storage container itself, it can be safely carried outside.

(Effects of the Invention) As described above, the fallen slag recovery device of the present invention has a rotary table with a cylindrical side wall to constitute a slag receiving tank, a dam plate is provided in this receiving tank, and a slag is crushed in the upper part. Since the structure is equipped with beams, falling slag is crushed and scattered uniformly into the receiving tank, and the rotation of the rotary table allows the slag to be easily collected at a certain point. It becomes possible to completely carry out the work using the carry-out machine.

Therefore, the recovery device of the present invention is capable of safely and reliably transporting fine slag, which is a by-product, by remote control during the cutting operation of nuclear reactor dismantling.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view illustrating the dismantling work of a nuclear reactor. FIGS. 2 to 4 are illustrative of the slag recovery device of the present invention. FIG. - An explanatory view taken along the line A; FIG. 3 is an explanatory view taken along the line B-B in FIG. 1; FIG. 4 is an explanatory diagram taken along the line CC in FIG. 3. 1... Nuclear reactor, la... Reactor head, lb...
Hearth bottom. 80...Slag collection device, 81...Bucket. 82... Rotary table, 83... Cylindrical side wall. 84...Slag receiving tank, 85...Weir plate. 86... Crushing beam, 87... Bucket input port.

Claims (1)

[Claims] 1. A slag receiving tank is formed by installing a cylindrical side wall on a rotary table placed at the bottom of the furnace, and a weir plate is provided in the slag receiving tank, and a crushing beam is provided at the top. A falling slag recovery device characterized by being provided. 2. The falling slag recovery device as set forth in claim 1, wherein a bucket inlet is provided at the front upper part of the weir plate in the rotational direction.