JPH0140080Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cutting device suitable for processing waste materials inside a nuclear reactor.

For example, fuel assemblies, control rods, and various other parts are arranged inside a nuclear reactor, and when they are used, they need to be stored in an appropriate storage location. (made of zirconium), control rods (made of stainless steel), etc. are required to be cut to appropriate dimensions to save space.

However, since these parts are radioactive, it is necessary to cut them in pure water at a depth of more than 3 meters inside the reactor.

The first feature of the present invention is that cutting is performed by an electric discharge cutting method using the insulating properties of pure water.

Although the present invention requires an automatic device due to its purpose, the present invention uses a cassette-type running electrode for discharge cutting. Assuming it runs, it will take about 100 minutes to dispose of it, and the cassette electrode will be discarded after use. The use of this cassette electrode is the second feature of the present invention.

When cutting, cutting waste is generated. In the discharge cutting method, the running electrode is charged with a negative charge and the waste material to be processed is charged with a positive charge, so there is less cutting waste compared to the reversely charged electrode arc cutting method. need to be excluded. The third feature of the present invention is that a water flow is applied from the outside of the cassette to the inside of the cutting section to generate a circulating flow using a pump, thereby collecting cutting waste in a strainer or filter and processing it together with the cassette electrode. shall be.

The external dimensions of the cassette electrode are such that it can be accommodated in a 560φ x 800mm cylindrical container according to the regulations of the Atomic Energy Research Institute, etc., and this is the fourth feature of the present invention.

The fifth feature of the present invention is that the cassette electrode is structured so that it can be easily attached to the attachment part of the main body of the cutting machine suspended above the water surface.

Furthermore, the sixth feature of the present invention is that the cutting machine main body is mounted on a guide provided in contact with the inner wall of the water tank, and can be raised and lowered with minute power by means of a balance weight, and has an electrode winding reel drive device and a pump inside. Built-in,
The cutting current is controlled to be kept constant by an electrode feed control device at the top of the water tank.

An example of implementing the present invention will be described below with reference to FIGS. 1A and 1B and FIG. 2, in which a control rod is cut.

In the figure, 1 is an electrode cassette, 2 is an electrode wire reel, 3 is a take-up reel, 4 is a pinch roller, 5 is a guide roller, and the electrode wire 6 is cut by the main body 8 of the cutting machine.
The drive device inside guides the take-up reel 3 in the direction of the arrow, and cuts the control rod 7. The electrode cassette 1 is replaceably attached to the cutting machine main body 8. A water flow is applied to the electrode cassette 1 in the direction of the arrow from the pump 9 in the cutting machine main body 8 through the filter 10, and the cutting waste from cutting the control rod 7 is carried by this water flow to the electrode cassette in front of the strainer 11. 1 and will not be scattered outside. Reference numeral 12 is a lid which is opened to receive the control rod 7, and closed to perform the cutting operation.

The electrode cassette 1 is attached to the cutting machine main body 8 as shown in FIG. 2, and the above-mentioned operations are performed by the cutting machine main body 8. The cutting machine main body 8 is guided by a guide device 13 and can move mainly up and down, and also slightly back and forth, so that it can move from one end of the control rod 7 to the center, then axially, and then outward from the other end. Can perform cutting work. A balance weight 14 suspends the cutting machine body 8 via a wire 15 and a guide roller 16, and allows it to be raised and lowered with a small amount of power. Reference numeral 16 denotes an electrode feed control device that controls and feeds the cutting current so as to keep it constant.

Thus, according to the present invention, waste materials inside a nuclear reactor can be cut automatically from above a safe water tank, and all the cutting debris generated at this time is collected in an electrode cassette and taken out and stored in a designated radioactive waste tank. Therefore, it provides an extremely useful means for the disposal of nuclear reactors that will occur in the future.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, and FIGS. 1A and 1B are a cutaway plan view and a cutaway front view showing the structure of the main part. FIG. 2 is a side view of the entire device. The symbols in the drawings indicate the following members, respectively. 1: electrode cassette, 2: electrode wire reel, 3: take-up reel, 4: pinch roller, 5: guide roller,
6: Electrode wire, 7: Control rod, 8: Cutting machine body,
9: pump, 10: filter, 11: strainer, 12: lid, 13: guide device, 14: balance weight, 15: wire, 16: electrode feed control device.

Claims (1)

[Scope of utility model registration request] A replaceable electrode cassette is attached to the main body of the cutting machine which can be raised and lowered at a depth of 3 m or more in the pool, and the electrode cassette includes an electrode wire for discharge cutting, a free electrode wire reel for winding the electrode wire, comprising a take-up reel for the electrode wire driven from the cutting machine main body, and a strainer for collecting cutting waste into the electrode cassette, and
The electrode cassette is shaped like a housing, and has an electrode wire reel and a take-up reel arranged symmetrically, and has a lid at the center of the front for taking in and out waste materials to be processed, such as control rods. A pipe for water flow is provided which branches toward the front of the section to the left and right and communicates with strainers at the rear of both sides, and a pinch roller and a guide roller for supporting the electrode wire are provided in the pipe. A cutting device suitable for processing waste materials inside nuclear reactors.