JPH03287376A - Blasting method in decontamination work - Google Patents

Abstract

PURPOSE:To surely prevent the most likely radioactivated dust from leaking to the closed space external part, by executing the blasting work in the closed space and performing it while taking clean air inside the closed space as well as discharging the air in the closed space to the external part. CONSTITUTION:A blasting work is performed while taking in fresh air as well as discharging the air inside a closed space 20 to the external part by a discharging device 30, inside the closed space(house) 20. Accordingly, the dust, etc., splashed and floated inside the closed space 20 by blasting work are discharged outside the closed space 20. In this case, the dust, etc., can be collected by filters 35, 36 by interposing the filters 35, 36 in the discharge route for discharging air.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a blasting method in decontamination work, and particularly relates to a blasting method in decontamination work that can improve the working environment and improve work efficiency. It is something.

[Conventional technology]

A blasting method is one of the methods for removing sludge and the like adhering to equipment and the like.

As is well known, the blasting method uses sand (for example, sand) on the surface of the workpiece.
It is a type of polishing process that removes rust and foreign matter (sludge, etc.) from the surface by bombarding it with a blasting material made of sand (usually silica sand) or iron particles. In the above, when sand is used as the blasting material, it is called a sandblasting method, and when iron particles are used, it is called a grid blasting method. Furthermore, recently, blasting methods using resin-made blasting materials have been implemented because the hardness of the blasting materials in conventional sandblasting or grid blasting methods is too high and may damage the product.

During blasting, the blasting material collides with the workpiece, the dust of the blasting material crushed by the collision, the sludge removed by the blasting material, etc. are scattered around.

Therefore, conventionally, when blasting is performed, a specific closed space has been constructed to prevent the blasting material and sludge from scattering over a wide area, and the work has been performed within the closed space.

[Problem to be solved by the invention]

By the way, during blasting work for decontaminating nuclear equipment, the sludge adhering to the equipment may be radioactive, so the removed sludge or crushed blasting material may be removed from the closed space. leakage to the outside must be completely prevented.

In addition, when blasting is carried out in a narrow closed space as described above, dust from the crushed blasting material and sludge as described above will thickly fill the closed space, extremely reducing visibility and causing problems in terms of work hygiene. There were also some issues that I didn't like.

Furthermore, when blasting is performed using the conventional method described above, it is necessary to wait for the dust that has filled the space to settle down after the blasting process is completed before processing the sludge blasting material that has been scattered around. This was done by scraping up the sludge, blasting material, etc. that had fallen on the floor, which was extremely inefficient.

The present invention was made in view of the above circumstances, and it is possible to reliably prevent the leakage of generated dust to the outside when blasting nuclear equipment equipment, create a good working environment, and efficiently. The purpose of this invention is to provide a blasting method for decontamination work that allows for efficient work.

[Means to solve the problem]

In the invention described in claim 1 of the present invention, when performing blast processing for decontaminating nuclear power equipment, the blasting work is carried out in a closed space, and the air in the closed space is discharged to the outside. The method is characterized in that it is carried out while introducing clean air into the closed space.

In addition, the invention described in claim 2 of the present invention provides a method in which, when carrying out the blasting method in the decontamination work described in claim 1, a filter is provided in the middle of the exhaust route for discharging the air in the closed space. The present invention is characterized in that dust particles floating in the closed space are collected by a filter.

Furthermore, the invention described in claim 3 of the present invention is characterized in that, in the blasting method for decontamination work according to claim 1 or 2, the closed space is configured to have a double structure.

[Effect]

By performing blasting work in a closed space while expelling the air in the closed space to the outside and taking in fresh air, the dust scattered and suspended within the closed space due to the blasting work is discharged outside the closed space. .

At that time, by interposing a filter in the exhaust path for discharging air, the dust and the like can be collected by the filter.

Further, when the closed space is doubled, leakage of dust and the like to the outside can be more reliably prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The figure shows an outline (concept) of equipment for carrying out the blasting method according to the present invention, that is, decontamination blasting equipment.

This decontamination blasting equipment 1 includes a blasting device IO, a house 20 forming a closed space CiA in which the blasting operation is performed, and an exhaust device 30 for discharging the air inside the house 20.

The blasting device IO is a commonly used dry blasting device. Further, here, as the blasting material, a material made of resin mainly containing melamine resin is used.

In this embodiment, the house 20 is connected to the inner house 20A through a space between the inner house 20A and the inner house 2OA.
It has a double structure with an outer house 20B surrounding 0'A. Both the inner and outer houses 2OA and 20B are formed by, for example, stretching a vinyl sheet around a frame.

In addition, a vinyl sheet is attached to the floor, and the joints such as the joints between walls and ceilings or between walls and floors are completely covered.
0B constitutes a closed space.

Further, although not shown, both houses 2OA and 20B are provided with doors for people to enter and exit. Reference numeral 2 in the figure indicates the workpiece to be decontaminated, and the actual blasting work is thus performed within the inner house 2OA. Therefore, the nozzle 11 for spraying the blasting material of the blasting device 10 is set in the inner house 2OA via the hose 12.

In addition, in this case, the worker 3 who performs the blasting work is
The blasting work is performed in a space between the inner house 20A and the outer house 20B, that is, located outside the inner house 2OA. The code 4 in the figure is the inner house 2OA
These are rubber gloves that allow the worker 3's arm to be inserted while keeping the inside sealed. Also, Inner/Outer House 20
A, 20B are each provided with an opening 21.22 for taking in outside air, and both openings 21.
Prefilters 23 and 24 are attached to the filters 22, respectively. Also, although not shown, both houses 2OA,
20B is provided with a door for people to enter and exit. In addition, the code 25 is installed in the inner house 2OA,
This is a protective note to catch blasting material that scatters during blasting work.

The exhaust device 30 includes a chamber 31 having one end opened inside the inner house 20A, a wind pipe 32 extending from the other end of the chamber 31, and a blower 33 provided at one end of the wind pipe 32. , and a damper 34 for adjusting air volume interposed in the middle of the wind pipe 32. In the chamber 31, a pre-filter 35 is disposed near the opening, and a HEPA (High Efficiency) filter is disposed downstream of the pre-filter 35.
cy Paticulate Air) Filter 36
is installed.

Next, as an example, the blasting method according to the present invention will be described along with the operation of the decontamination blasting equipment I having the above configuration.

Set the workpiece 2 at a predetermined position in the inner house 20A,
When the worker 3 takes a predetermined position inside the outer house 20B (outside the inner house 20A), first, the exhaust device 30
The blower 33 is operated.

By operating the blower 33, air within the inner house 20A is drawn from the chamber 31 and discharged to the outside.

By creating a negative pressure inside the inner house 20A, outside air is introduced into the inner house 2OA through the opening 21. Moreover, since the internal space of the outer house 20B also has a negative pressure, outside air is introduced into the outer house 20B through the opening 22.

Under the above conditions, operate the blasting device IO, and the nozzle]
A blasting material is sprayed from 1, and the workpiece 2 is subjected to blasting.

During the blasting process, the sludge removed from the surface of the workpiece 2 by the blasting material or the workpiece 2
The dust of the blasting material crushed by the collision with the blasting material is scattered into the inner house 2OA. However, here,
Since the air inside the inner house 2OA is sucked by the blower 33, the scattered dust is absorbed into the chamber 31.
Among these dust particles, relatively large particles are collected by the pre-filter 35, and fine particles that have passed through the pre-filter 35 are collected by the HEPA filter 36. Further, the suction air from which the dust has been removed passes through the wind pipe 32 and is discharged to the outside. Further, clean air from the outside is introduced into the inner house 2OA through the opening 21 and constantly replaces the contaminated air inside. The amount of exhaust air inside the inner house 2OA can be adjusted by the damper 34 in consideration of the dust generation situation.

After the required work is completed, the blasting device 10 is stopped, but the exhaust device 30 is then operated for a while to remove the dust remaining in the inner house 2OA through the prefilter 35 and the HE P.
It is collected by the A filter 36.

In this way, when carrying out the blasting work for decontamination, the present invention is carried out in the closed space C, and the air in the closed space C is constantly exhausted to a predetermined location outside. It is possible to reliably prevent the leakage of generated dust, which may be contaminated with dust, to the outside of the closed space C.

In addition, since clean air is taken in from the outside as the air is exhausted, the environment inside the closed space C is constantly purified, reducing the burden on the worker 3 and improving visibility at hand. becomes more efficient. Furthermore, since the generated dust is gradually treated by the pre-filter 35 and HEPA filter 36 in the chamber 31 during the work, there is no need to wait for the dust to settle after the work is finished, and the processing efficiency is improved.

Further, in this embodiment, since the closed space C, that is, the house 20, is constructed in double layers, leakage of dust to the outside of the closed space can be more reliably prevented. In addition, in the example, the inner house 2OA and the outer house 20B
Since the pre-filters 23 and 24 are installed in the openings 2 and 22, which are the outside air intake ports of the houses 20A and 20B, in the unlikely event that the internal pressure of the houses 20A and 20B increases during work, Also, those openings 2
1.22, the dust inside the inner house 20A will not leak to the outside.

〔Effect of the invention〕

As explained above, according to the blasting method for decontamination work according to claim 1, it is possible to reliably prevent generated dust that may be radioactive from leaking to the outside of a closed space. In addition, since clean air is taken in from outside as the air is exhausted, the environment inside the closed space is constantly purified, reducing the burden on workers, and improving visibility at hand, making work more efficient.

In addition, according to the blasting method in decontamination work according to claim 2, the generated dust is gradually collected during the work, so there is no need to wait for the dust to settle after the work is completed, and processing efficiency is improved. improves.

Furthermore, according to the blasting method for decontamination work according to claim 3, since the closed space is configured to have a double structure, leakage of dust to the outside of the closed space can be more reliably prevented.

[Brief explanation of the drawing]

The figure is an overall schematic configuration diagram showing an example of the configuration of blasting equipment used to implement the blasting method in decontamination work according to the present invention. 10...20...2OA...30...35...36...Blast device, House (closed space),...Inner house, 20B...Exhaust device, Pre-filter -HEPA filter ...outer house,

Claims (3)

[Claims] (1) When performing blasting for the decontamination of nuclear equipment, the blasting work is carried out in a closed space, and the air in the closed space is exhausted to the outside and clean air is introduced into the closed space. A blasting method for decontamination work that is characterized by being carried out while incorporating. (2) When carrying out the blasting method in decontamination work according to claim 1, a filter is provided in the middle of the exhaust route for discharging the air in the closed space, and the filter captures dust floating in the closed space. A blasting method in decontamination work that is characterized by the (3) The blasting method for decontamination work according to claim 1 or 2, characterized in that the closed space has a double structure.