JPH11248876A - Method for recoating suppression chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to efficiently conduct a recoating work for a suppression chamber. SOLUTION: The base processing work for exfoliating an existing coat and the coating work for forming a new coating by spraying paint are carried out in order of mention in each of working areas 9 with small spaces to be recoated which are circumferentially divided by temporary walls 8 in the inside space of a suppression chamber 5. This method restrains a return phenomenon of an exposed part on a surface of a member attributed to a lapse of time after the base processing work has finished. After an abrasive sweeper used for the base processing work is recovered and reused, working scaffoldings 10 are installed in every other one of the working areas 9 respectively and the base processing work and the coating work have finished, the working scaffoldings 10 are moved to other adjoining working areas 9 where the work has not finished yet in order to reduce the volume of radioactive wastes associated with the recoating work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repainting a suppression chamber attached to a reactor containment vessel.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show an example of nuclear reactor equipment. This nuclear reactor equipment includes a reactor pressure vessel 1 serving as a steam generation source, a containment vessel main body 2 having an open upper end, and a containment vessel. A reactor containment vessel 4 comprising an upper lid 3 for closing the opening of the vessel body 2 and containing the reactor pressure vessel 1, and a torus-shaped suppression chamber 5 surrounding a lower part of the reactor containment vessel 4 in a circumferential direction. And a vent pipe 6 whose upper end communicates with the containment vessel 4 and whose lower end communicates with the suppression chamber 5. When the reactor equipment is in operation, water is always contained in the suppression chamber 5. 7 are stored.

Further, the lower end of the vent pipe 6 is immersed in water 7 in the suppression chamber 5, and supplies the steam discharged when the main steam pipe (not shown) in the reactor containment vessel 4 is damaged. The water is guided from the vent pipe 6 into the water 7 in the suppression chamber 5 so as to be condensed, thereby suppressing an increase in the pressure in the containment vessel 4.

[0004] The inner surface of the suppression chamber 5 is coated with an inorganic zinc-rich paint having a high rust prevention effect and an epoxy resin paint having excellent water resistance. In order to prevent corrosion of the inner surface, repainting work is performed every predetermined period.

[0005] When performing repainting work, a work scaffold is erected around the entire circumference of the suppression chamber 5, and a ground treatment for removing the existing coating film by projecting the abrasive material is performed on the inner surface of the suppression chamber 5. After that, the paint is sprayed on the inner surface to form a new coating film.

[0006]

However, since the above-described undercoating and coating operations are performed on the entire inner surface of the suppression chamber 5, the dust and the paint when the existing coating film is peeled off and when the paint is sprayed are removed. Ventilation and dust collection equipment for removing mist, and dehumidifying the internal space of the suppression chamber 5 in order to suppress the occurrence of a return phenomenon in which an oxide coating film is formed on the surface of the member from which the existing coating film has been peeled off. The air conditioning equipment must have a large capacity, and it is not easy to control the negative pressure in the suppression chamber 5 to prevent the scattering of floating dust to the outside.

[0007] If the phenomenon occurs in which the surface of the member returns to the portion where the surface of the member has already been exposed due to a failure of the air conditioning equipment or the like during the base treatment, the base treatment for the part must be repeated.

Further, all of the abrasive material scattered all around the inside of the suppression chamber 5 and the components of the work scaffold must be treated as radioactive waste,
The amount of radioactive waste generated during repainting is enormous.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to enable a repainting work of a suppression chamber to be performed efficiently.

[0010]

In order to achieve the above object, a method for repainting a suppression chamber according to the present invention comprises the steps of:
A plurality of work sections are circumferentially divided by a plurality of temporary walls to form a plurality of work sections, a work scaffold is erected every other work section, and a cleaning material is provided on an inner surface of the work section where the work scaffold is erected. To remove the existing coating film, and to remove the existing coating film.Then, the abrasive material and the dust from which the coating film has been removed are sucked out of the suppression chamber to collect the cleaning material and capture the dust. After performing a painting operation in which a new coating film is formed by spraying paint on the inner surface of the work area where the processing operation has been completed, the work scaffold of the work area where the coating operation has been completed is moved to a ground treatment operation adjacent to the work area. Move to another work area where painting work has not been performed yet, and perform groundwork to remove the existing coating by projecting abrasives on the inner surface of the work area where the work scaffold has been moved. Remove the abrasive material and dust After collecting the abrasive material by sucking it out of the chamber and catching dust, spraying paint on the inner surface of the work area where the groundwork was completed, forming a new coating film, then painting work The work scaffold in the work section where the operation has been completed and the temporary wall dividing the internal space of the suppression chamber are carried out to the outside of the suppression chamber.

In the method for repainting a suppression chamber according to the present invention, a base treatment for peeling off an existing coating film and a paint for removing a paint film are provided for each work section in which the internal space of the suppression chamber is circumferentially divided by a plurality of temporary walls. Spray paint work to form a new coating film sequentially,
The return phenomenon of the exposed portion of the member surface due to the lapse of time after the completion of the base treatment operation is suppressed.

In addition, the abrasive material projected on the inner surface of each work section is collected and reused to reduce the amount of abrasive material used.

[0013] Further, after work scaffolds are erected every other work section and ground treatment work and painting work are performed,
The work scaffold is relocated to another adjacent work section where the foundation treatment work and the painting work have not been performed, thereby reducing the number of components of the work scaffold relative to the total length of the erection.

[0014]

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

FIGS. 1 to 4 show an embodiment of a method for repainting a suppression chamber according to the present invention.
Parts denoted by the same reference numerals as those in FIG. 5 represent the same items.

At the time of repainting work, water is drained to clean the inner surface of the suppression chamber 5, and
The inside of the suppression chamber 5 is air-dried.

Next, the internal space of the suppression chamber 5 is divided into a plurality of sections in the circumferential direction by a plurality of temporary walls 8 to form a plurality of working sections 9, and a working scaffold 10 is provided every other working section 9. Erect.

Further, a blast device 12 for feeding grit (abrasive material) to a projection nozzle 11 carried by a worker entering the suppression chamber 5 and a grit collecting device 13 having a vacuum pump are provided in the suppression chamber 5. Install outside.

At the time of the preparation process, a ventilation section (A / C) already installed in the reactor facility is connected to a work section 9 where the preparation process is to be performed through a temporary duct or the like, and the ventilation / collection is performed by the ventilation device. The work section 9 is subjected to negative pressure management by performing dust, thereby preventing a large amount of floating dust generated in the foundation treatment work from diffusing into the other work section 9 and improving the work environment.

In this state, the worker wearing the protective clothing enters the work compartment 9 where the work scaffold 10 is erected, and the inner surface of the suppression chamber 5 where the undercoating work for removing the existing coating film is to be performed. Aim the projection nozzle 11 at
The grit sent from the blasting device 12 is projected through the projection nozzle 11 and the position is appropriately changed by using the work scaffold 10 while performing the groundwork on the entire inner surface in the work compartment 9. .

At the same time as the start of grit projection, the grit collecting device 13 is operated to continuously vacuum collect the grit projected into the work compartment 9 and supply the grit to the blast device 12.

At this time, the grit collecting device 1 is smaller than the air discharge amount for grit projection by the blast device 12.
The amount of air suction for collecting the grit by 3 is slightly increased so that the grit is efficiently collected.

Further, dust such as floating dust generated in the undercoating process is captured separately from the grit by the filter of the ventilation device.

After the completion of the base treatment, grit, dust and the like scattered on the blast surface and the work scaffold 10 are collected and cleaned by an air blow, a vacuum cleaner, a plaster brush or the like by the blast device 12.

Thereafter, a coating operation of forming a new coating film by spraying a coating material on the inner surface of the suppression chamber 5 in the work compartment 9 in which the base treatment operation has been completed is sequentially performed. Operate the existing ventilator in the equipment to perform the prescribed ventilation.

The work scaffolding 10 in the work section 9 where the base work and the painting work have been completed is relocated to the work section 9 in which the base work has not been performed yet. The painting operation is performed according to the same procedure as that described above.

As described above, in the method for repainting the suppression chamber shown in FIGS. 1 to 4, the work space 9 having a small area to be repainted, which is obtained by dividing the internal space of the suppression chamber 5 in the circumferential direction by the plurality of temporary walls 8. In addition, the undercoating process of peeling off the existing coating film and the painting work of spraying paint to form a new coating film are sequentially performed, so the return phenomenon of the exposed surface of the member due to the passage of time after the completion of the undercoating work Can be suppressed, and the repainting work for the suppression chamber 5 can be performed efficiently.

Further, since the grit projected on the inner surface of each working section 9 is collected by the grit collecting device 13 and supplied to the blast device 12, the amount of grit used can be reduced.

Further, the work scaffolds 10 are erected every other work section 9 and after the work in the work section 9 is completed, the work scaffolds 10 are relocated to another adjacent work section 9. In addition, the number of constituent members of the work scaffold 10 with respect to the total installation length is reduced, and the amount of radioactive waste generated due to the repainting work can be reduced.

The method of repainting the suppression chamber of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0031]

As described above, according to the method for repainting the suppression chamber of the present invention, the following various excellent effects can be obtained.

(1) For each work section having a small area to be repainted, in which the internal space of the suppression chamber is divided by a plurality of temporary walls in the circumferential direction, a ground treatment for peeling off the existing coating film and spraying new paint. Since the coating operation for forming a coating film is sequentially performed, it is possible to suppress the return phenomenon of the exposed portion on the surface of the member due to the lapse of time after the completion of the substrate treatment operation, and it is possible to efficiently perform the re-coating work on the suppression chamber.

(2) Since the abrasive material projected on the inner surface of each working section is collected, the collected abrasive material can be reused and the amount of abrasive material used can be reduced.

(3) After working scaffolds are erected every other work section and work is performed on the groundwork and painting,
Since the work scaffold is relocated to another adjacent work section where the base treatment and the painting work have not been performed, the number of components of the work scaffold relative to the total length of the erection can be reduced.

(4) The amount of abrasive material used is reduced, and the number of components of the work scaffold is reduced, so that the amount of radioactive waste generated during repainting can be reduced. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an embodiment of a method for repainting a suppression chamber of the present invention.

FIG. 2 is an enlarged view taken along the line II-II of FIG.

FIG. 3 is an enlarged view taken along the line III-III of FIG. 1;

FIG. 4 is a conceptual diagram of a grit collecting device and a blast device related to FIG.

FIG. 5 is a conceptual diagram illustrating an example of a nuclear reactor facility.

FIG. 6 is a plan view of the suppression chamber related to FIG. 5;

[Explanation of symbols]

 5 Suppression chamber 8 Temporary wall 9 Work section 10 Scaffold for work

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidetaka Yoshikuni 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawashima Harima Heavy Industries, Ltd. Yokohama Engineering Center (72) Inventor Yasuaki Sakai 5 Tsukiji, Chuo-ku, Tokyo No. 4-14 Ishikawajima Plant Construction Co., Ltd. (72) Inventor Kazuo Kawasaki 5-4-14 Ishikawajima Plant Construction Co., Ltd. (72) Inventor Suzuki Daichiro 5 Tsukiji, Chuo-ku, Tokyo Chome 4-14 Ishikawajima Plant Construction Co., Ltd. (72) Inventor Shuji Miyahara 517-4 Kamoshidacho, Aoba-ku, Yokohama-shi, Kanagawa

Claims (1)

[Claims] An internal space of a hollow annular suppression chamber is divided in a circumferential direction by a plurality of temporary walls to form a plurality of work sections, and a work scaffold is erected every other work section to perform the work. Performs groundwork to remove the existing coating by projecting abrasives on the inner surface of the work area where the scaffolding is installed, and sucks the abrasives and dust from which the coating has been peeled out of the suppression chamber. After collecting the cleaning material and capturing dust, spraying paint on the inner surface of the work area where the groundwork was completed to form a new coating film, and then completing the work area where the painting work was completed The work scaffold is moved to another work space adjacent to the work space where the groundwork work and painting work have not been performed, and abrasive material is projected on the inner surface of the work space to which the work scaffold has been transferred. Remove existing coating The groundwork is performed, and the abrasive and dust from which the coating film has been removed are sucked out of the suppression chamber to collect the abrasive and collect the dust. After performing a painting operation of spraying paint to form a new coating film, the work scaffold of the work section where the painting operation is completed and the temporary wall dividing the internal space of the suppression chamber are carried out to the outside of the suppression chamber. A method for repainting a suppression chamber.