JPH06300892A - Decontaminating device for pipe-shaped waste - Google Patents

Abstract

PURPOSE:To reduce the generation of such secondary waste as sludge and sawdust and enable decontamination of inside by arranging each device of a dry blast, airblow, contamination density measurement along the transportation path. CONSTITUTION:Inside of a sealed casing 1 is partitioned into a fat removing room 2, a dry blast room 3, an airblow room 4 and a surface contamination density measuring room 5. Pipe-shaped waste W is transported as it is without being cut vertically. An inner surface fat removing device 6 washes inside of waste W with an elevating rotary brush 7 by supplying fat removing liquid such as ethanol. A dry blast device 9 blows off grinding material together with compressed air from an elevating blast head 10 and grinds the inner surface of the waste W. An airblow device 18 blows off compressed air into the waste W from an elevating nozzle 19 to eliminate the grind dust. A surface contamination density measuring device 21 elevates up and down a radiation sensor 22 to measure the surface contamination density of the waste W and confirms the completion of decontamination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decontamination apparatus for radioactive waste contaminated pipe-like waste generated from a nuclear power plant or the like.

[0002]

2. Description of the Related Art In nuclear power plants and the like, oil drain pipes and gas pipes may be removed during remodeling work, etc., but since radioactive materials adhere to the inside of the removed pipes, In the past, these pipes were cut to an appropriate length, stored in drums as pipe-shaped waste, and stored in a storage location. However, in this method, for example, to store 7 tons of 2-3 inch pipe-shaped waste,
The problem was that it required 60 200-liter drums and required a large storage space.

In order to solve such a problem, the present inventors first developed a pipe-like waste decontamination apparatus. Focusing on that only the inner surface of the pipe-shaped waste is contaminated with radioactivity, the pipe-shaped waste is automatically vertically divided by a band saw or the like to expose the inner surface.
Pipes that do not have oil adhered to them are directly blasted, and pipes that have oil adhered to them are degreased with ethanol, etc., and then blasted to decontaminate the inner surface of the pipe-shaped waste after decontamination. If the surface contamination density is less than a predetermined value, it will be treated as general industrial waste.

This method is extremely superior to the conventional method, but has a problem that a large amount of chips and saw blade scraps are generated when the pipe-shaped waste is vertically divided by a band saw or the like. . The amount of generated waste is about 100 kg, which accounts for about 40% of the secondary waste, while the total amount of secondary waste generated for the above-mentioned 7 tons of pipe-shaped waste is about 260 kg. Things were increasing.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, reduces the generation of secondary waste such as chips and saw blade scraps, and reduces the inner surface of pipe-shaped waste. It has been completed to provide a decontamination device for pipe-shaped waste that can be decontaminated.

[0006]

DISCLOSURE OF THE INVENTION The decontamination apparatus for pipe-shaped waste of the present invention, which has been made to solve the above-mentioned problems, has a pipe-shaped waste without vertically dividing the pipe-shaped waste contaminated with radioactivity. Along the path of transfer as it is, the inner drive blast device for the pipe-shaped waste, the inner air blow device,
A surface contamination density measuring device is arranged.

[0007]

According to the apparatus for decontaminating pipe-shaped waste of the present invention,
After degreasing the inside of the pipe-like waste contaminated with radioactivity as necessary without vertically dividing it into a pipe-like shape,
Decontamination of the inner surface is performed by the inner drive last device and the inner air blow device. Then, after confirming that the surface contamination density of the pipe-shaped waste after decontamination is not more than a predetermined value by a surface contamination density measuring device, it is taken out to the outside. Therefore, the generation of chips and sawdust is eliminated, and the amount of secondary waste generated can be significantly reduced.

[0008]

The present invention will be described in more detail below with reference to the illustrated embodiments. FIG. 1 is a cross-sectional view schematically showing the decontamination apparatus of the embodiment, in which 1 is an airtight casing which is divided into a degreasing chamber 2, a drive last chamber 3, an air blow chamber 4, and a surface contamination density measuring chamber 5. There is. W is a pipe-shaped waste and is sequentially transported through these chambers as indicated by arrows by an appropriate transfer means (not shown) such as a transfer robot. In the present invention, the pipe-shaped waste W is transferred as it is in the form of a pipe without vertically splitting the waste.

An internal degreasing device 6 for the pipe-shaped waste W is installed in the degreasing chamber 2. This is a device for cleaning the inner surface of the pipe-shaped waste W with a rotating brush 7 that moves up and down while supplying a degreasing liquid such as ethanol, and removes the attached oil and fat. The deposits are collected in the sludge collection tank 8 below. Incidentally, in the case of pipe-shaped waste without adhesion of oil and fat, it is transferred to the drive last chamber 3 as it is, since the treatment using this device is not necessary.

In the drive-last chamber 3, waste pipe W
The inner drive last device 9 is installed. This is a device for injecting an abrasive together with compressed air from a lifting blast head 10 to grind the inner surface of the pipe-shaped waste W. The grinding dust is collected by the hopper 11 together with the grinding material and classified by the classifier 12, and the grinding material is collected in the blast tank 17 and then sent to the blast head 10 again by compressed air. Further, the grinding dust is collected in the dust collection tank 13. The exhaust gas from the classifier 12 is completely filtered by the bag filter 14 and the HEPA filter 15, and then discharged from the blower 16 into the atmosphere. Furthermore, this exhaust system is designed to simultaneously suck air and gas in each room.

In the air blow chamber 4, an inner air blow device 18 for the pipe-shaped waste W is installed. This is a device for injecting compressed air to the inner surface of the pipe-shaped waste W from a lifting type nozzle 19 to completely remove grinding dust. The removed dust is collected in the dust collection tank 20.

In the surface contamination density measuring chamber 5, a surface contamination density measuring device 21 for the inner surface of the pipe-shaped waste W is installed. This is an apparatus that moves the radiation sensor 22 up and down to measure the surface contamination density of the pipe-shaped waste W after decontamination. Then, after confirming that decontamination has been completed by this device, the pipe-shaped waste W is taken out of the airtight casing 1 and disposed of as general waste.

[0013]

As described above, according to the pipe-like waste decontamination apparatus of the present invention, the inside surface of the pipe-like waste W, which is radioactively contaminated, remains pipe-like without vertically splitting. Since the decontamination can be performed, it is possible to eliminate the chips and saw blade scraps generated during vertical division. Therefore, it is possible to significantly reduce the amount of secondary waste. Further, the pipe-shaped waste W after decontamination can be disposed of as general waste. Therefore, the present invention, as a pipe-like waste decontamination device that solves the conventional problems, has a great contribution to the industrial development.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a decontamination device of an example.

[Explanation of symbols]

 W Pipe-shaped waste 9 Inner drive-last device for pipe-shaped waste 18 Air blower for inner surface of pipe-shaped waste 21 Surface pollution density measuring device for pipe-shaped waste

Claims (1)

[Claims] 1. An inner drive last device, an inner air blow device, and a surface contamination of a pipe-like waste along a path for transferring the pipe-like waste contaminated by radioactivity as a pipe-like form without vertically dividing it. A decontamination device for pipe-shaped waste, comprising a density measuring device.