JPH09281296A - Laser decontamination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove substances on a water surface without scattering them by holding the insides of an intermediate cylinder and an external cylinder under negative pressure, sucking the water surface to be decontaminated to their tips, and generating an air flow from the inside of the intermediate cylinder to the inside of the external cylinder. SOLUTION: The tip of the external cylinder 24 is made to abut against the wall surface 21 of a nuclear reactor container 2 filled with water and a suction device 33 is placed in operation to reduce the pressure in the external cylinder 24, and air is sent from an air sending device 30 to the inside of the intermediate cylinder 22. At this time, the quantity of suction is made larger than the quantity of air sending to hold the insides of the intermediate cylinder 22 and external cylinder 24 under negative pressure, thereby bringing the tips of the intermediate cylinder 22 and external cylinder 24 into contact with the wall surface 21. After the water in the external cylinder 24 is discharged, air flows are generated from an air sending pipe 29 to a suction pipe 31 through the inside of the intermediate cylinder 22 and the space at the outer periphery of the external cylinder 24. The substances sticking on the wall surface 21 are broken and peeled, but the tips of the intermediate cylinder 22 and external cylinder 24 are in contact with the wall surface 21, so they are never scattered into the pressure container 2. Further, the peeled substances are carried to a filter 32 with the air flowing in the suction pipe 31.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laser decontamination apparatus for removing contaminants adhering to a wall surface.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a nuclear power generation facility. Reference numeral 1 is a containment vessel barrel composed of a reinforced concrete structure and a metal liner, and 2 is a reactor pressure vessel made of metal. A cylindrical pressure vessel pedestal 3 that supports the reactor pressure vessel 2 is integrally erected on the containment vessel body 1 at a substantially central portion of the body 1.

At the upper end of the pressure vessel pedestal 3, a reactor shield wall 4 is erected so as to surround the reactor pressure vessel 2.

A basin seal bellows 13 is provided between the upper end of the outer circumference of the reactor pressure vessel 2 and the upper end of the inner circumference of the liner of the containment vessel 1 to maintain water tightness.

Reference numeral 5 is a diaphragm floor composed of a frame of a reinforced concrete structure and a metal liner, and the diaphragm floor 5 is a pressure vessel pedestal 3
From the outer surface to the inner surface of the storage container body 1 in a substantially horizontal manner.

In the dry well 6 which is a space surrounded by the upper surface of the diaphragm floor 5 and the inner surface of the containment vessel body 1, a water supply pipe 7 connected to the reactor pressure vessel 2, a main steam pipe 8 and various In the suppression chamber 9, which is a space in which devices not shown are arranged and which is surrounded by the lower surface of the diaphragm floor 5 and the inner side surface and the inner bottom surface of the containment vessel body 1, steam ejected when the main steam pipe 8 breaks. The water for condensing the water and for suppressing the pressure increase inside the storage container body 1 is stored.

Reference numeral 10 denotes a top head. The top head 10 is provided on an upper portion of the containment vessel body 1 so as to close an opening formed in the containment vessel body 1 so as to be located immediately above the reactor pressure vessel 2. It is placed and bolted to the containment body 1.

Reference numeral 11 denotes a spent fuel pool composed of a skeleton having a reinforced concrete structure and a metal liner. The spent fuel pool 11 is provided on the upper side of the containment vessel body 1.

Further, in FIG. 3, 12 is an operation floor, 14 is a shroud, 15 is a fuel rod, 41 is an overhead crane, and 42 is a pressure vessel upper lid.

In the nuclear power generation facility shown in FIG. 3, when inspecting the inside of the reactor pressure vessel 2, the top head 10 is removed from the containment vessel body 1 by the overhead crane 41 and the pressure vessel upper lid 42 is removed. After removing from the reactor pressure vessel 2, water as a shielding material is filled in the inside of the reactor pressure vessel 2 and the portion above the basin seal bellows 13 of the containment vessel body 1, and further, by the overhead crane 41. , A steam dryer and a steam separator (not shown) from the inside of the reactor pressure vessel 2, a shroud 14,
The fuel rods 15 and the like are carried out to the fuel pool 11.

Next, an underwater television camera (not shown) is hung from the operation floor 12 inside the reactor pressure vessel 2, and this underwater television camera is operated by remote control to photograph the inside of the reactor pressure vessel 2. However, the inside of the reactor pressure vessel 2 is visually inspected through a television monitor (not shown) installed on the operation floor 12.

[0012]

However, various nozzles provided on the inner surface of the body of the reactor pressure vessel 2 and the body of the reactor pressure vessel 2 and communicating with the water supply pipe 7, the main steam pipe 8 and the like. There are cases where pollutants such as oxides of the metal forming the reactor pressure vessel 2 and the nozzles are formed in the area where the inside of the reactor pressure vessel 2 is connected to the inner peripheral surface of the reactor. May be difficult to check.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a laser decontamination apparatus capable of removing a substance adhering to a wall surface without scattering.

[0014]

In order to achieve the above object, in the laser decontamination apparatus of the present invention, an optical fiber inserted into the inner cylinder so that one end can face the wall surface to be decontaminated, An intermediate cylinder which surrounds the inner cylinder in the circumferential direction and whose open end can be in close contact with the wall surface to be decontaminated,
A dust remover that surrounds the intermediate cylinder in the circumferential direction and has an outer cylinder whose open end can be in close contact with the wall surface to be decontaminated, and communicates the inside and outside of the intermediate cylinder with the vicinity of the tip of the intermediate cylinder. A hole is bored, one end of the air supply pipe is made to communicate with the space between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the intermediate cylinder, and the other end of the air supply pipe is connected to the air supply device. By connecting one end of the suction pipe to the space between the surface and the inner peripheral surface of the outer cylinder, connecting the other end of the suction pipe to the suction device, and connecting the other end of the optical fiber to the laser generator. There is.

In the laser decontamination apparatus of the present invention, the tips of the intermediate cylinder and the outer cylinder are brought into contact with the wall surface to be decontaminated, and the suction amount of the suction device and the air feeding device becomes larger than the air feeding amount. When operated in such a manner, the intermediate cylinder and the outer cylinder are adsorbed to the wall surface, and the space between the air pipe from the inside of the intermediate cylinder, the dust removal hole, and the outer peripheral surface of the intermediate cylinder and the inner peripheral surface of the outer cylinder. An airflow is generated that flows through the suction pipe to the suction pipe.

Next, when the laser generator is operated,
The substance adhering to the wall surface to be decontaminated by the laser light emitted from the optical fiber is crushed and peeled off, and the peeled substance is conveyed to the filter by the air flow and captured.

[0017]

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

FIGS. 1 and 2 show an example of an embodiment of the laser decontamination apparatus of the present invention, in which 16 is an optical fiber, and the tip portion of the optical fiber 16 is an elongated inner cylinder 17. It is inserted inside.

The base end of the optical fiber 16 is connected to a laser generator 18 such as CO ₂ , excimer or YAG provided on the operation floor 12, and the laser generator 1 is connected to the laser generator 18.
The laser light emitted from the laser beam 8 enters the condenser lens 19 attached to the tip of the inner cylinder 17 through the optical fiber 16, and the laser light 20 condensed by the condenser lens 19 irradiates the wall surface 21. It is supposed to be done.

The laser generator 18 described above has a laser beam 20 having an energy density sufficient to achieve heat transmission to the substance (eg, oxide) to be removed by the decontamination process.
Is to be emitted.

An intermediate cylinder 22 surrounding the inner cylinder 17 in the circumferential direction is attached to the outside of the inner cylinder 17 via a stay 23, and the tip end side of the intermediate cylinder 22 expands in a funnel shape and the inner cylinder is formed. It extends to the front from the tip of 17 and is in an open state.

The intermediate cylinder 2 is provided outside the intermediate cylinder 22 described above.
An outer cylinder 24 that surrounds 2 in the circumferential direction is provided, and the tip end side of the outer cylinder 24 also expands like a funnel like the intermediate cylinder 22 and extends to approximately the same plane as the distal end of the intermediate cylinder 22 in an open state. Has become.

The base end of the outer cylinder 24 is closed by an end plate 25, and the base end of the inner cylinder 17 described above is fixed to the end plate 25 while penetrating the end plate 25. The base end of 22 is fixed to the inner surface of the end plate 25.

The tip end portion of the intermediate cylinder 22 and the outer cylinder 2
The tip end side portion of 4 is formed of a highly elastic material such as a rubber-based material so as to be easily brought into close contact with the wall surface 21 to be decontaminated.

A plurality of dust removing holes 26 are formed in the vicinity of the widened front end of the intermediate cylinder 22, and the dust removing holes 26 allow the inside of the intermediate cylinder 22 to be located near the front end of the intermediate cylinder 22. The fluid flows from that space to the space between the outer peripheral surface of the intermediate cylinder 22 and the inner peripheral surface of the outer cylinder 24.

On the outer surface of the end plate 25 of the outer cylinder 24, the intermediate cylinder 2
A lid-shaped body 27 having substantially the same diameter as that of No. 2 is fixed, and the above-mentioned optical fiber 16 penetrates through the lid-shaped body 27 and has a tip end portion of the inner cylinder 1.
7 and the inside of the lid 27 is the end plate 2
A communication hole 28 formed in 5 communicates with the inner rear end of the intermediate cylinder 22.

The optical fiber 16, the inner cylinder 17, the condenser lens 19, the intermediate cylinder 22, the outer cylinder 24, the end plate 25, and the lid 27 constitute a decontamination device body 36.

The tip of the air supply pipe 29 is opened inside the lid 27, and the base end of the air supply pipe 29 is connected to an air supply device 30 such as a blower pump or an air tank provided on the operation floor 12. It is connected.

Inside the outer cylinder 24, the tip of the suction pipe 31 penetrating the end plate 25 is open, and the base end of the suction pipe 31 is the filter 3 provided on the operation floor 12.
It is connected via 2 to the suction port of a suction device 33 such as a suction pump.

A hanger 34 is attached to the outside of the outer cylinder 24, and is installed on the operation floor 12 so as to be movable along the circumferential direction of the reactor pressure vessel 2. The payout end of the wire 35 paid out from the winding device 40 is locked.

Therefore, when the wire 35 is wound around or taken out from the winding device 40, the decontamination device body 36 moves up and down with respect to the reactor pressure vessel 2, and the winding device 40 is moved to the reactor pressure vessel 2. When moved along, the decontamination device body 36 moves in the circumferential direction with respect to the reactor pressure vessel 2.

Further, the discharge pipe 37 of the suction device 33 communicates with the suppression chamber 9.

In carrying out an inspection of the inside of the reactor pressure vessel 2, when removing contaminants such as a metal oxide film formed on the inner surface of the body of the reactor pressure vessel 2,
After removing the top head 10 from the containment vessel body 1 and the pressure vessel upper lid 42 from the reactor pressure vessel 2 with the overhead crane 41, the inside of the reactor pressure vessel 2 and the basin seal bellows 13 of the containment vessel body 1 are removed. The upper part is filled with water as a shielding material.

Further, by an overhead crane 41, a steam dryer and a steam separator (not shown) and the shroud 1 are shown.
4, the fuel rod 15 and the like are carried out to the fuel pool 11.

Then, the wire 35 is unwound from the winding device 40 installed on the operation floor 12 to hang the decontamination device main body 36 inside the reactor pressure vessel 2, and to remove the pressure of the reactor filled with water. The decontamination device body 36 is moved so that the tip of the outer cylinder 24 contacts the underwater wall surface 21 of the container 2.

Next, the suction device 33 is operated with the tip of the outer cylinder 24 in contact with the wall surface 21 to reduce the pressure inside the outer cylinder 24 via the filter 32 and the suction pipe 31, and
Air is supplied from the air supply device 30 to the inside of the intermediate tube 22 through the air supply pipe 29, the inside of the lid-shaped body 27, and the communication hole 28.

At this time, the suction amount of the suction device 33 is made larger than the amount of air supplied from the air supply device 30 to the inside of the intermediate cylinder 22, and the inside of the intermediate cylinder 22 and the outer cylinder 24 becomes negative pressure. The intermediate cylinder 22 and the outer cylinder 24 to the wall surface 21.
To remove the water inside the outer cylinder 24 from the air supply pipe 29 to the inside of the intermediate cylinder 22, the dust removal hole 26, and the intermediate cylinder 22.
An airflow flowing into the suction pipe 31 through the space between the outer peripheral surface of the outer cylinder 24 and the inner peripheral surface of the outer cylinder 24 is generated.

When the laser generator 18 is operated in this state, the laser beam 20 emitted from the tip of the optical fiber 16 and condensed by the condenser lens 19 is applied to the wall surface 21 to be decontaminated, A substance (for example, an oxide) attached to the wall surface 21 is crushed and separated from the wall surface 21.

At this time, the tip of the intermediate cylinder 22 and the outer cylinder 24
Since the tip of the above is in close contact with the wall surface 21, the exfoliation material 38 such as oxide does not scatter inside the reactor pressure vessel 2.

Further, the stripping substance 38 is the air supply pipe 29.
From the inside to the inside of the intermediate cylinder 22, the dust removal hole 26, and the space between the outer peripheral surface of the intermediate cylinder 22 and the inner peripheral surface of the outer cylinder 24 to be conveyed to the filter 32 by the air flow flowing to the suction pipe 31, To be captured.

After removing the pollutants formed on the wall surface 21 in this way, the underwater television camera is hung from the operation floor 12 inside the reactor pressure vessel 2 and the inside of the reactor pressure vessel 2 is visually inspected. To do.

The laser decontamination apparatus shown in FIGS. 1 and 2 can also be used for decontamination of the suppression chamber 9 and the inner wall of a general water tank.

When the suppression chamber 9 and the inner wall of the water tank are decontaminated by the laser decontamination apparatus shown in FIGS. 1 and 2, a portion inside the suppression chamber 9 where water does not reach or an upper portion of the water tank. A winding device is attached to the device, and the wire 35 is paid out from the winding device 40 so that the decontamination device main body 36 faces the suppression chamber 9 or a portion of the inner wall of the water tank located below the water surface. Decontamination work is performed according to various procedures.

When the optical fiber 16, the air supply tube 29, and the suction tube 31 shown in FIG. 1 are integrated as a cable, the decontamination device main body 36 can be easily handled.

The laser decontamination apparatus of the present invention is not limited to the above-mentioned embodiment, and the laser decontamination apparatus of the present invention is applied to the decontamination treatment of the wall surface existing in the atmosphere. Needless to say, various changes can be made without departing from the scope of the present invention.

[0046]

As described above, in the laser decontamination apparatus according to the present invention, the tips of the intermediate cylinder and the outer cylinder are brought into contact with the wall surface to be decontaminated, and the suction device and the air supply device are sucked by the suction amount. When it is operated so as to be larger than the air supply amount, the intermediate cylinder and the outer cylinder are adsorbed to the wall surface, and the inside of the intermediate cylinder, the dust removal hole, the outer peripheral surface of the intermediate cylinder and the outer cylinder Since an airflow that flows through the space between the inner peripheral surface and the suction tube is generated, it is possible to obtain an excellent effect that the substance adhered to the wall surface to be decontaminated by the laser light can be removed without scattering.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of an embodiment of a laser decontamination apparatus of the present invention.

FIG. 2 is a vertical cross-sectional view showing an example of a usage mode of the laser decontamination apparatus shown in FIG.

FIG. 3 is a vertical sectional view showing an example of a nuclear reactor power generation facility.

[Explanation of symbols]

 16 optical fiber 17 inner cylinder 18 laser generator 20 laser light 21 wall surface 22 intermediate cylinder 24 outer cylinder 26 dust removal hole 29 air supply pipe 30 air supply device 31 suction pipe 33 suction device

Claims (1)

[Claims] 1. An optical fiber inserted into an inner cylinder so that one end can face a wall surface to be decontaminated, and a distal end that surrounds the inner cylinder in the circumferential direction and is open for decontamination. An intermediate cylinder that can be in close contact with the wall surface of the intermediate cylinder, and an outer cylinder that surrounds the intermediate cylinder in the circumferential direction and has an open tip that can be in close contact with the wall surface to be decontaminated, A dust removal hole that communicates the inside and the outside of the tube is bored, one end of the air supply pipe communicates with the space between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the intermediate cylinder, and the other end of the air supply pipe Connected to the air device, one end of the suction pipe is communicated with the space between the outer peripheral surface of the intermediate cylinder and the inner peripheral surface of the outer cylinder, the other end of the suction pipe is connected to the suction device, A laser decontamination device having the other end connected to a laser generator.