JPH09105799A - Disassembling method by cutting for nuclear power plant facilities - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the recovery of cut pieces, and allow the remote control of disassembling work by cutting a reactor from the upper surface by the cutting blade of a cutting device suspended by a rotating device. SOLUTION: The whole device is integrated, and a cutting device 3 and a fixing device 6 are suspended by a rotating device 2. A cutting blade 5 cuts a reactor by its own rotation from the upper surface of the reactor, and the cutting position is moved by the rotation of the device 3. Further, the device 3 is lowered down by a lifting/lowering device 4 to perform the cutting, and the reactor is cut down from the upper part. The device 6 prevents the slippage in cutting of the whole device by protruding arms in four directions to the reactor inner wall. The chip by cutting fallen onto the reactor bottom is sucked or magnetically recovered, and housed in a radioactive waste container. The operation of the whole device is remotely performed by a control board set on a concrete floor.

Description

Detailed Description of the Invention

[0001] The present invention uses cutting blades to cut chips into chips and facilitates collection of the chips. Further, since the cutting is sequentially performed from the upper surface of the nuclear reactor, the cutting is continuously performed, which enables continuous cutting.

[Prior Art] The conventional method (JPDR of the Japan Atomic Energy Research Institute, Tokai Research Institute) is based on gas cutting or cutting with a tip saw in water, but it is a great work to treat radioactive contamination of smoke and water during or after cutting. There is a drawback that becomes. There is also a drawback in that it is difficult to collect the cut pieces.

[Problems to be Solved by the Invention] In the present invention, since the cutting blade can be used for a long time of about 12 hours, continuous cutting is possible, and since the cutting pieces are in the form of chips, Pieces are collected by a simple method using suction or magnetic force, and the operator does not enter the reactor by collecting the cutting pieces, which is very useful for reducing the exposure dose of the operator.

[Means for Solving the Problems] The present invention does not require precision of mechanical work because it is a simple work of cutting from the upper surface in spite of the mechanical work of using a cutting blade. Also, since the continuous use time of the cutting blade is long,
Continuous cutting is possible.

BEST MODE FOR CARRYING OUT THE INVENTION A disassembly method by cutting a nuclear reactor will be described with reference to the drawings. The apparatus shown in FIG. 1 is 1, an apparatus in which the entire apparatus except an operation panel is integrated, and 2 is a rotating apparatus. It has a structure in which 5, the cutting device, the cutting device 6, and the fixing device are suspended. 5. The cutting blade cuts from the upper surface of the reactor by the rotation of the cutting blade itself. 3. The cutting position of the cutting blade is gradually moved by the rotation of the cutting device. Down to continue cutting, and the cutting surface of the reactor is cut down. 6. The fixing device has a structure in which the arm is extended in four directions on the inner wall of the reactor in order to prevent the whole device from slipping due to vibration during cutting. Cutting chips fall to the bottom of the reactor, are collected by suction or magnetic force, and are stored in a radioactive waste storage container. The operation of the entire equipment is done remotely by the operation panel installed on the concrete floor.

[Advantages of the Invention] The advantages of the present invention are listed below. 1) Since it is a simple operation of cutting sequentially from the top of the reactor, continuous operation is possible. 2) Since the cutting pieces are chips, it is easy to collect and store the cutting pieces. 3) Since the operation of the device is remote operation, the worker does not enter the furnace, and the exposure of the worker can be greatly reduced. 4) Since the operation of the device is continuous operation, the work cost can be greatly reduced.

[Examples] [0007] In the examples, since the example of disposal of a commercial nuclear reactor is not currently in Japan, an experiment was conducted using a milling machine (using a cutting blade) of its own factory. (Hardness material) was cut, and the time required for cutting was measured to obtain about 4 months, which is the working time on an actual machine. Chromium-molybdenum steel thickness 100 mm, width 100 m
m, 150 mm long material, cutting thickness 5 mm, cutting width 1
An average value of 20 minutes was obtained by performing the experiment 10 times for the material to be completely ground under the conditions of 00 mm and a cutting length of 150 mm. Excluding the volume of the reactor of about 22.6 m ³ under the condition that the material volume of 0.0015 m ³ is cut in 20 minutes, it will be about 16 months, and by using 4 cutting blades, about 4 months of It becomes the cutting work period and can be implemented.

[Brief description of the drawings]

FIG. 1 is a schematic elevational view of the present invention.

[Explanation of symbols]

 1 Operation panel 2 Rotating device 3 Cutting device 4 Lifting device 5 Cutting blade 6 Fixing device

Claims (1)

[Claims] 1. A method of dismantling a nuclear power plant facility (for example, a nuclear reactor) by cutting (a) Dismantling by cutting. (B) Cut chips into chips. (C) Collect the cut pieces by suction or magnetic force and store them in a storage container.