JP2001099987A - Laser polishing device for interior of nuclear reactor piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device for the interior of reactor piping capable of easily and surely polishing the interior of reactor piping. SOLUTION: This laser polishing device for the interior of reactor piping has a cylindrical main body 35, a head holding part 37 attached movably in the axial direction and rotating direction in respect to the cylindrical main body 35, and a laser head 42 held by the head holding part 37. Supporting leg parts 31a and 31b arranged at a predetermined interval in the circumferential direction are attached to the main body 35. The support leg parts 31a and 31b are protruded by a cylinder 33 built in the main body and abutted to an interior of a piping 22 for fixing the main body 35 inside the piping 22. The laser head 42 is connected to a laser oscillator 38 via an articulated arm 34 and a laser beam is radiated from the laser head 42 for polishing the interior of the piping 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear reactor piping for polishing and checking the integrity of a nuclear reactor piping for preventive maintenance of piping and equipment disposed inside and outside a reactor pressure vessel and the inside of equipment. Laser polishing apparatus.

[0002]

2. Description of the Related Art A boiling water reactor is, as shown in FIG.
It has a reactor pressure vessel 1, in which a coolant 2 and a reactor core 3 are accommodated. The core 3 includes a plurality of fuel assemblies (not shown), control rods, and the like. The core 3 is housed in a core shroud 4.

In a reactor pressure vessel 1, a coolant 2 is
The gas flows upward through the inside, and at that time, the temperature is raised and pressurized by the nuclear reaction heat of the reactor core 3, and a two-layer flow state of water and steam is formed.
The coolant 2 that has become a two-layer flow flows into the steam separator 5 installed above the reactor core 3 and is separated into water and steam. Among them, the steam is introduced into a steam dryer 6 installed above the steam separator 5, dried to become dry steam, and is not shown via a main steam pipe 7 connected to the reactor pressure vessel 1. It is transferred to a steam turbine and used for power generation.

On the other hand, the separated water flows down the reactor core 3 via the downcomer 8 between the reactor core 3 and the reactor pressure vessel 1. A plurality of jet pumps 9 are installed at equal intervals around the outer periphery of the core shroud 4 in the downcomer portion 8. A control rod guide tube 10 is provided below the core 3.
Is installed below the control rod guide tube 10.
A control rod drive mechanism 11 is provided. The control rod drive mechanism 11 controls the insertion and withdrawal of a control rod (not shown) into and from the reactor core 3 via the control rod guide tube 10.

[0005] A reactor recirculation pump (not shown) is provided outside the reactor pressure vessel 1. The reactor recirculation pump and the jet pump 9, and a reactor recirculation pipe connecting the two, are used. , Constituting the reactor recirculation system. That is, driving water is supplied to the jet pump 9 by the reactor recirculation pump, and the jet pump 9 forcibly circulates the coolant 2 into the reactor core 3 by the supplied driving water.

As shown in FIGS. 9 and 10, the jet pump 9 has a riser pipe 12 at the center, and this riser pipe 12 is supplied into the reactor pressure vessel 1 from a reactor recirculation pump. The coolant 2 is introduced via a recirculation inlet nozzle 13.

[0007] A pair of left and right elbows 15a, 15b are connected to the upper part of the riser tube 12 via a transition piece 14. Each of the elbows 15a, 15b is connected to an inlet throat 17a via a mixing nozzle 16a, 16b. , 17b are connected. Diffusers 18a and 18b are connected to lower portions of the inlet throats 17a and 17b, respectively. When the coolant 2 is injected from the upper mixing nozzles 16a and 16b, the reactor water is drawn in from the surroundings. The coolant 2 injected and the reactor water entrapped in this way are mixed in the inlet throats 17a and 17b, and then the hydrostatic head is recovered by the diffusers 18a and 18b.

In the jet pump 9, fluid drive is generated by the flow of the coolant 2 sent from the reactor recirculation pump.
The lower end is welded to the recirculation inlet nozzle 13, and the upper end is connected to the reactor pressure vessel 1 through the riser brace 19.
It is fixed to.

The inflow water pressure of the driving water supplied through the riser pipe 12 acts on the elbows 15a and 15b at the upper end of the jet pump 9. Driving water is spouted from the nozzle (not shown) connected to the other ends of the elbows 15a and 15b toward the inlet throats 17a and 17b and the diffusers 18a and 18b by the inflow water pressure. The force acts upward.

The inlet throats 17a, 17b have mixing nozzles 16a, 16b and elbows 15a, 15a at their upper ends.
5b, it is connected to the transition piece 14 and the lower end is inserted into the upper end of the diffusers 18a, 18b.

The lower ends of the diffusers 18a and 18b are fixed to a shroud support 20 welded to the reactor pressure vessel 1. Further, as shown in FIGS. 9 and 11, the lower end of the riser tube 12 has a riser elbow. 21 is welded. The riser elbow 21 is welded to a thermal sleeve 22, and the thermal sleeve 22 is connected to the recirculation inlet nozzle 13 fixed to the reactor pressure vessel 1.

Further, the inlet throats 17a, 17b
Is a riser blanket 23 fixed to the riser tube 12.
Attached to. This prevents the riser tube 12 and the inlet throats 17a, 17b from vibrating.

The riser brace 19 is shown in FIGS.
As shown in FIG. 2, there are a pad 24 provided on the inner wall of the reactor pressure vessel 1 and four thin plates 25 welded to the pat 24. The four thin plates 25 have a thickness of 10 mm.
Before and after. The four thin plates 25 are integrally formed with each other by a block 26 at the tip thereof, and the riser tube 12 is formed.
Are welded inside the block 26. Therefore, the riser brace 19 suppresses the fluid vibration generated in the riser pipe 12 during the operation of the reactor. In addition, riser brace 1
Numeral 9 is for absorbing the difference in thermal expansion between the reactor pressure vessel 1 made of carbon steel and the riser pipe 12 made of austenitic stainless steel. Therefore, during the operation of the reactor, the reactor is in a deformed state as a state in which the difference in thermal expansion is absorbed.

As described above, the jet pump 9 is connected to the coolant 2.
Is used under severe conditions compared to other in-furnace equipment in order to pressurize and circulate in the core 3, a large load acts on the members connected to the jet pump 9,
In particular, a large stress acts on the riser brace 19 that supports the riser tube 12 in the middle.

[0015]

An excessive load acts on the jet pump 9 due to, for example, the breakage of an external pipe such as a reactor recirculation pipe, or the riser pipe 12 is caused by any cause. When rust is generated on the inner surface, the rust may develop into a crack or the like of the riser pipe 12. In addition, since the austenitic stainless steel pipe is mainly used as the material of the riser pipe 12, stress corrosion cracking (Stress Corrosion cracking) occurs when the three conditions of stress, corrosion environment, and material (generation of a chromium deficient layer) are satisfied. It is assumed that riser tube 12 is damaged due to occurrence of Ctacking).

Since this stress corrosion cracking phenomenon does not occur if at least one of the above three conditions is missing, various measures must be taken to prevent the stress corrosion cracking.

If rust or cracks are generated on the surface of the jet pump 9 for some reason, if these are left undisturbed, the cracks proceed and the jet pump 9
Cracks may occur.

Therefore, it is not preferable that the jet pump 9 for controlling the output of the nuclear reactor be in such a state, because it may adversely affect other structures.

The present invention has been made in view of the above points, and a laser polishing apparatus in a reactor pipe which can reliably polish a predetermined position on a pipe inner surface installed inside and outside a reactor pressure vessel. The purpose is to provide.

[0020]

SUMMARY OF THE INVENTION The present invention relates to a laser polishing apparatus in a reactor pipe for laser-polishing the inside of a cylindrical reactor pipe. And a supporting leg that abuts on the inner surface of the reactor pipe to fix the main body, and a laser oscillator connected to a laser head held by the main body via an articulated arm. A laser polishing apparatus in a reactor pipe, which is movable in an axial direction and a rotational direction with respect to a main body.

The present invention is characterized in that the laser head irradiates the laser beam at a position shifted several millimeters in the radial direction from the center of the reactor pipe, thereby eliminating laser irradiation to the laser head due to the reflection of the laser beam. Laser polishing apparatus in a reactor pipe.

In the present invention, a plurality of support legs of the main body are provided at predetermined intervals in the circumferential direction, and each of the support legs is driven by a cylinder so that the axis of the reactor pipe and the axis of the main body are the same. This is a laser polishing apparatus in a reactor pipe characterized by being a core.

According to the present invention, there is provided a laser polishing apparatus in a reactor pipe, wherein the laser head is disposed on the side of the articulated arm of the main body or on the side opposite to the articulated arm.

The present invention is a laser polishing apparatus in a reactor pipe, wherein the articulated arm and the laser head are connected so that the articulated arm is not twisted when the laser head rotates.

According to the present invention, there is provided a laser polishing apparatus in a reactor pipe, wherein a suction pipe is provided in the vicinity of a laser head, and polishing powder separated from the pipe by laser polishing can be collected by the suction pipe. .

According to the present invention, there is provided a laser polishing apparatus in a reactor pipe, further comprising a CCD camera and a lighting device, wherein a laser polishing state is checked by the CCD camera and the lighting device.

[0027] The present invention is a laser polishing apparatus in a reactor pipe, further comprising a ferrite indicator, wherein the position of a weld in the reactor pipe can be detected by the ferrite indicator.

According to the present invention, the laser in the reactor pipe is characterized in that the laser oscillator coaxially oscillates a polishing laser beam and a pointer laser beam continuously oscillating at a different wavelength from the polishing laser beam. It is a polishing device.

According to the present invention, there is provided a laser polishing apparatus in a reactor pipe, characterized in that laser light for a pointer is confirmed by a CCD camera and a lighting device.

The present invention is a laser polishing apparatus in a reactor pipe, further comprising a sandpaper polishing apparatus for finishing and a buff polishing apparatus, wherein laser polishing, sandpaper polishing and buff polishing can be performed simultaneously. .

[0031]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are views showing an embodiment of a laser polishing apparatus in a reactor pipe according to the present invention.

As shown in FIGS. 1 and 2, the laser polishing apparatus 30 in a reactor pipe includes a cylindrical main body 35 disposed in a cylindrical reactor pipe, for example, a thermal sleeve 22.
A head holder 37 movably mounted in the main body 35 in the axial direction and the rotation direction; and a laser head 42 held by the head holder 37 and irradiating a laser beam.

The main body 35 has support legs 31a, 31b arranged at a predetermined distance from each other in the circumferential direction.
Are provided, and rubbers 32a, 32b are attached to the tips of the support legs 31a, 31b. Body 35
A cylinder 33 for driving the support legs 31a and 31b in the radial direction is built in the inside. The cylinder 33 presses the rubbers 32a and 32b of the support legs 31a and 31b against the inner surface of the thermal sleeve 22 so that the main body 35 is formed. It is held at a predetermined position in the thermal sleeve 22.

FIG. 1 shows a state in which the support legs 31a and 31b are opened within the thermal sleeve 22. Support leg 3
1a and 31b are provided with rubber 32 as described above.
Since a and 32b are attached, stable fixing can be performed in the thermal sleeve 22. In addition, the support leg 31
The a and 31b are simultaneously opened and closed by the cylinder 33. As described above, the cylinder 33 and the support legs 31a and 31b are provided in the cylindrical main body 35, and the main body 35 has open ports at a plurality of places for the access of the support legs 31a and 31b. Have been.

In the center of the main body 35, a hollow guide tube 3 is provided.
The articulated arm 34 having a plurality of pipes 69 connected to each other by a rotating part 62 is connected to the right side of FIG.
A laser oscillator 38 is connected to 4 via a joint 39. In addition, the rotating portion 62 of the guide tube 36 and the articulated arm 34
Incorporates a quartz glass mirror.

A laser head 42 held by a head holder 37 is connected to the left side of the guide tube 36 in FIG. The axial movement and the rotational movement of the head holder 37 with respect to the main body 35 are performed by a drive unit such as an electric motor and gears built in the main body 35. Further, a cylinder is built in the head holding portion 37 so as to open and close the laser head 42.

During laser polishing, the recirculation inlet nozzle 1
Suction hose (suction tube) into thermal sleeve 22 from 3
40 is inserted and the suction pump 41 collects fine powder.

As shown in FIG. 1, a CCD camera and a lighting device 50 described later are arranged in the riser tube 12.

Next, the operation of the present embodiment having the above configuration will be described.

First, as shown in FIG. 1, the rubbers 32a, 32b of the support legs 31a, 31b are pressed against the inner surface of the thermal sleeve 22 by the cylinder 33 built in the main body 35, and the main body 35 is positioned at a predetermined position in the thermal sleeve 22. Fix it. At this time, the axis of the main body 35 matches the axis of the thermal sleeve 22. Next, the laser light oscillated from the laser oscillator 38 is transmitted to the articulated arm 34.
Is guided to the laser head 42 through the guiding pipe 36 by
The rust generated on the reactor pipe, for example, the inner surface of the riser elbow 21 can be polished by the laser light emitted from the laser head 42.

The polishing powder of, for example, an oxide film peeled off from the inner surface of the riser elbow 21 is then sucked by the suction hose 40.

When the polishing position is changed by changing the direction of the laser beam emitted from the laser head 42, the head holding portion 37 is extended in the axial direction with respect to the main body 35, or the head holding portion 37 is moved in the rotation direction. (See FIG. 2).

When the head holder 37 is rotated to change the direction of rotation of the laser head 42, the guide tube 3
6 does not rotate, so that the articulated arm 30 does not twist in the rotational direction. Also, the head holding unit 37
The laser head 42 mounted on the laser beam irradiates the laser beam from a position shifted several millimeters in the radial direction with respect to the axis of the reactor pipe such as the thermal sleeve 22, so that the laser beam is reflected from the reactor pipe. The returning laser light does not return to the laser head 42.

Next, a modified sequence of the present invention will be described with reference to FIG. 1 and 2, an example is shown in which a head holding portion 37 for holding the laser head 42 is provided on the side of the cylindrical body 35 opposite to the articulated arm 34. However, the present invention is not limited to this. A head holder 37 for holding the laser head 42 may be provided on the side of the multi-joint arm 34 (FIG. 3).

In FIG. 3, the lifting device 5 is inserted into the riser tube 12.
The main body 35 is moved in the riser tube 12 in the axial direction by the pulling tool 52. A power supply device 55 is connected to the rear of the laser oscillator 38 via a cable 56.

Next, a modification of the articulated arm 34 will be described with reference to FIG. The articulated arm 34 has a plurality of pipes 69 connected to each other by a rotating part 62. The laser light generated from the laser oscillator 38 is applied to the laser light path 6.
0, rises at a mirror section 61 provided below the articulated arm 34, passes through mirrors incorporated in each of the rotating sections 62 to 68, and transmits from the joint section 70 to the laser head 42 via the pipe 69. Will be done. A reinforcing plate 71 is incorporated in each pipe 69, and a weight 72 is attached to an end of the reinforcing plate 71 to maintain the balance of the articulated arm 34. Next, a modified example of the laser oscillator 38 will be described with reference to FIG. As shown in FIG. 5, the laser oscillator 38 includes a polishing laser light oscillating section 91 for generating a polishing laser light, a pointer laser light oscillating section 89 for generating a pointer laser light at a wavelength different from the polishing laser light, and have.

The polishing laser light and the pointer laser light oscillate coaxially, and are mirrored by the mirror 88 and the driving mirror 92.
Is sent to the laser head 42 side. In FIG. 5, reference numeral 90 denotes a rear mirror.

The laser light for the pointer is thereafter confirmed by the CCD camera and the lighting device 50. Based on this confirmation result, the position adjustment of the laser beam is performed by the drive mirror 92.

The polishing laser beam used in the polishing includes:
It is required that the pulse time width is short and the instantaneous energy density is high. Further, the wavelength of the oscillated laser light to be irradiated differs depending on the oscillation efficiency of the laser light and the material of the irradiation target.
Nd: YAG in solid-state laser light with relatively good oscillation efficiency
In the case of a laser, the wavelength is 1064 nm for the fundamental wave and 532 nm for the second harmonic. In the case of an Er: YAG laser, it is 2.94 μm. These laser lights have an oscillation pulse time as short as 5 to 10 ns, and the irradiation state cannot be monitored by the CCD camera and the lighting device 50.

Therefore, as described above, continuous-wave laser beams having different oscillation wavelengths are coaxially arranged and used as pointer laser beams. The pointer laser light can be coaxially arranged by being incident from the rear mirror 90 of the polishing laser light oscillator 91. This method can be used even when an excimer laser of a gas laser is used as the polishing laser light.

Next, another modified example will be described with reference to FIGS.

As shown in FIGS. 6 and 7, the laser head 42 of the laser polishing apparatus 30 is provided with a window 85 through which the laser beam 82 is transmitted. A sandpaper polishing device 83 held by 83a and a buff polishing device 84 held by a swing leg 84a are provided.

The sandpaper polisher 83 and the buff polisher 84 are used when the laser polisher 30 is inserted into a reactor pipe, for example, the thermal sleeve 22, when the swing legs 38a,
84a is housed inside the laser head 42 (FIG. 6).
(A)).

After removing the oxide film in the thermal sleeve 22 by polishing with the laser beam 82, the sandpaper polishing device 83 and the buff polishing device 84 are moved by the swing legs 83a,
The projection 84a projects outward of the laser head 42. Sandpaper polishing by a sandpaper polishing device 83 and buffing by a buff polishing device 84 are performed on the inner surface of the thermal sleeve 22 from which the oxide film has been removed by laser polishing with the laser light 82 (FIG. 6B).

In the polishing by the laser beam, the projections of the base material cannot be removed because they are not brought into contact like sandpaper polishing. On the other hand, it is possible to remove deposits even on the concave surface of the uneven surface in the thermal sleeve 22. In addition, after laser polishing, sandpaper polishing can be performed to achieve a smoother surface, and mirror polishing can be simultaneously performed by buffing. The abrasive particles separated from the inner surface of the thermal sleeve 22 by sandpaper polishing and buffing are cleaned by gas or liquid ejected from a gas or liquid fountain mechanism (not shown). In this case, when polishing is performed in a gas phase, cleaning is performed using a gas such as dry air, argon gas, helium gas, or nitrogen gas, and when polishing is performed in a liquid phase, a liquid such as pure water is used. And wash.

In FIGS. 6 and 7, for example, the polishing powder separated from the inner surface of the thermal sleeve 22 by the laser polishing with the laser light 82 is sucked by the suction hose 40 and the suction pump 41 (FIG. 1). The abrasive powder sucked by 41 is collected by a filter (not shown), and the radioactivity of this filter can be measured remotely and continuously or batchwise by a radioactivity meter.

The polishing powder peeled off by the laser polishing may adhere to the window 85 shown in FIG.
The abrasive powder attached to the window 85 can be removed by a gas (dry air, argon gas, helium gas, nitrogen gas) or liquid (pure water) ejection mechanism (not shown).

In each of the above embodiments, the main body 3
By moving the head holding unit 37 attached to the unit 5 in the axial direction with respect to the main body 35 by the driving unit and rotating the head holding unit 37 forward and reverse in the rotation direction, the laser head 42 irradiates all parts in the reactor pipe. Laser polishing can be performed with laser light.

Further, the laser beam from the laser head 42 may be irradiated on the outer surface of the reactor pipe or a structure other than the reactor pipe to be polished.

Further, a ferrite indicator (not shown) for detecting a welded portion in the reactor pipe may be provided, and the welded portion detected by the ferrite indicator may be irradiated with laser light to perform laser polishing.

Furthermore, laser beams may be applied to a portion of the reactor piping that is not dried or a portion filled with water to perform laser polishing on the piping. Further, the wavelength of the laser light oscillated from the laser oscillator 38 may be appropriately changed, and the laser light may be used not only for polishing but also for laser peening or laser derusting.

As described above, according to each of the above-described embodiments, the laser polishing apparatus 30 is installed at a predetermined position in the reactor pipe, and the polishing operation using the laser polishing apparatus 30 is performed by remote control for a short time. Can be reliably performed. In addition, it is possible to observe the polishing state while confirming the state with the CCD camera and the lighting device 50.

Further, according to the present invention, the laser head 42
Since the laser light from the substrate is used to peel off and grind an object attached to the inside of the pipe 22 in a non-contact manner, it can be applied to a concave surface in the pipe 22 and can be processed regardless of the uneven surface of the base material. . By irradiating the laser beam from the laser head 42 and operating the sandpaper polishing device 83 and the buff polishing device 84 together, a smoother polishing process can be performed simultaneously with the laser polishing. Also in this case, by performing the laser polishing before the polishing by the sandpaper polishing device 83 and the buff polishing device 84, the sandpaper polishing and the buff polishing can be performed after removing the rust on the concave surface.

[0064]

As described above, according to the present invention, a predetermined position in a reactor pipe can be easily and reliably polished. Therefore, the generation of rust in the reactor piping can be suppressed, and the formation of cracks can be prevented.

[Brief description of the drawings]

FIG. 1 is an installation diagram showing an embodiment of a laser polishing apparatus in a reactor pipe according to the present invention.

FIG. 2 is an operation state diagram of a laser polishing apparatus in a reactor pipe.

FIG. 3 is an installation state view showing another embodiment of the laser polishing apparatus in a reactor pipe according to the present invention.

FIG. 4 is a diagram showing a modification of the articulated arm.

FIG. 5 is a diagram illustrating a modified example of a laser oscillator.

FIG. 6 is a plan view showing a laser polishing apparatus having a sandpaper polishing apparatus and a buff polishing apparatus.

FIG. 7 is a perspective view showing a laser polishing apparatus having a sandpaper polishing apparatus and a buff polishing apparatus.

FIG. 8 is a sectional view of a boiling water reactor.

FIG. 9 is a perspective view showing a jet pump and peripheral devices thereof.

FIG. 10 is a partially cutaway view showing an elbow.

FIG. 11 is an essential part perspective view showing a riser pipe and a riser elbow.

FIG. 12 is a cross-sectional view showing a riser brace.

[Explanation of symbols]

 Reference Signs List 1 reactor pressure vessel 21 riser elbow 22 thermal sleeve 30 laser polishing device 31a, 31b support leg 32a, 32b rubber 33 cylinder 34 articulated arm 35 main body 36 guiding pipe 37 head holding part 38 laser oscillator 40 suction hose 41 suction pump 42 Laser head 83 Sandpaper polishing device 84 Buff polishing device 89 Laser oscillation unit for pointer 91 Laser oscillation unit for polishing

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitoichi Koichi 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Hamakawasaki Plant (72) Inventor Koichi Soma Tsurumi-ku, Yokohama-shi, Kanagawa 2-4 Suehirocho, Toshiba Keihin Works Co., Ltd. (72) Inventor Tsuyoshi Maehara 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Keihin Works Co., Ltd.

Claims (11)

[Claims] A laser polishing apparatus in a reactor pipe for laser polishing the inside of a cylindrical reactor pipe, comprising: a main body for holding a laser head for irradiating a laser beam; A support leg that contacts and fixes the main body; and a laser oscillator that is connected to the laser head held by the main body via an articulated arm. A laser polishing apparatus in a reactor pipe, which is movable in a direction. 2. The laser head according to claim 1, wherein the laser beam is irradiated at a position shifted a few millimeters in the radial direction from the center of the reactor pipe, thereby eliminating laser irradiation to the laser head due to reflection of the laser beam. The laser polishing apparatus in a reactor pipe according to claim 1. 3. A plurality of supporting legs of the main body are provided at predetermined intervals in a circumferential direction, each supporting leg is driven by a cylinder, and a shaft center in the reactor pipe and a shaft center of the main body are coaxial. 2. The laser polishing apparatus in a reactor pipe according to claim 1, wherein: 4. The laser polishing apparatus according to claim 1, wherein the laser head is disposed on the side of the multi-joint arm of the main body or on the side opposite to the multi-joint arm. 5. The laser polishing apparatus according to claim 1, wherein the articulated arm and the laser head are connected so that the articulated arm is not twisted when the laser head is rotationally moved. 6. The laser polishing apparatus according to claim 1, wherein a suction pipe is provided near the laser head, and the polishing powder separated from the pipe by laser polishing can be collected by the suction pipe. . 7. A CCD camera further comprising a CCD camera and a lighting device.
2. The laser polishing apparatus in a reactor pipe according to claim 1, wherein a laser polishing state is confirmed by a camera and a lighting device. 8. The laser polishing apparatus according to claim 1, further comprising a ferrite indicator, wherein a position of a weld in the reactor pipe can be detected by the ferrite indicator. 9. A nuclear reactor according to claim 1, wherein the laser oscillator oscillates coaxially a laser beam for polishing and a laser beam for a pointer which continuously oscillates at a different wavelength from the laser beam for polishing. Laser polishing equipment in piping. 10. The laser polishing apparatus according to claim 9, wherein the laser light for the pointer is confirmed by a CCD camera and a lighting device. 11. A sandpaper polishing device for finishing,
The laser polishing apparatus according to claim 1, further comprising a buff polishing apparatus, wherein the laser polishing, sandpaper polishing, and buff polishing can be performed simultaneously.