KR101429601B1 - laser peening apparatus of nuclear reactor - Google Patents

Abstract

The present invention relates to a laser beam peening apparatus for a nuclear reactor and a laser irradiating unit of a laser peening apparatus for improving the stress of a hemispherical reactor lower nozzle and a nozzle weld, An inner peripheral rail provided; A conveying part conveyed along the inner peripheral rail; A radial rail provided on the conveyance unit to guide the conveyance unit in a radial direction of the reactor; And a laser irradiating unit provided in the transferring part and irradiating a laser beam toward a welding part formed on the inner spherical surface of the reactor, wherein the irradiation angle of the laser beam is changed by tilting driving according to the shape of the welding part, .
Thus, it is possible to provide a reactor laser pinning apparatus capable of easily improving the stress even from the inner spherical surface of the reactor to the welded portion formed around the region where the outermost nozzle penetrates.

Description

[0001] The present invention relates to a laser peening apparatus for nuclear reactor,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser pinning apparatus for a nuclear reactor, and more particularly, to a laser pinning apparatus for a nuclear reactor, which is provided for surface modification through laser shot peening on a lower nozzle and a nozzle weld of a nuclear reactor.

Laser light has been used in various fields with its high energy density and coherence. Laser application technology has also been applied as a means of inspection, preventive maintenance, and repair in nuclear reactor nuclear reactor maintenance. For example, there is laser peening for repairing cracks in structures and the like, and laser peening for preventing stress corrosion cracking of structures in furnaces and the like.

Laser pinning is a preventive maintenance technique that uses Nd: YAG (neodymium: YAG) lasers. The laser light is condensed by a lens or the like, and is irradiated to the surface of the material to generate a plasma, and compression residual stress is imparted to the material by the shock wave of the plasma. Stress corrosion cracking occurs when material condition, environmental condition, and stress condition are satisfied. However, by laser peening, tensile stress or low compressive stress is put into a high compressive stress state, and stress corrosion cracking is prevented in the base material or weld .

When laser peening is applied to structures in nuclear reactors, a laser oscillator is placed on an operation floor to transfer laser light to a laser irradiation head installed at the bottom of the reactor. As a means for transmitting the laser light, there is a device in which a mirror is disposed inside a hollow light pipe, light is transmitted, and light is transmitted using an optical fiber.

An example of such a reactor laser pinning apparatus is disclosed in Korean Patent Publication No. 10-2012-0048692 (published on May 15, 2012, hereinafter referred to as "Patent Document 1").

Conventionally, a lower portion of a reactor is formed as a sphere, and a plurality of nozzles are penetrated through the inner spherical surface of the reactor so as to be exposed to the outside, and a weld is formed around each of the through- The welds formed around the outermost nozzles of the nozzles are formed at a relatively high inclination in the inner spherical surface of the reactor. The flow baffle and the flow baffle inner rings, etc., interference occurs which makes the pinning operation difficult.

However, since the laser pinning apparatus according to the prior art is provided so as to be irradiated with the laser beam so as to be fixed in the vertical direction, it is difficult to properly repair the weld formed around the region where the outermost nozzle penetrates from the inner spherical surface of the reactor. .

In addition, the shape of the welded portions is different according to working conditions including the shape of the inner spherical surface of the reactor, and the laser peening operation can not be actively performed according to different shapes and conditions of the welded portion, and can be performed uniformly.

In addition, since there is no separate mechanism for freely transferring the means for irradiating the laser beam, there is a problem in that the laser pinning apparatus can smoothly come close to all the welding portions formed at different positions on the inner spherical surface of the reactor, have.

Korean Patent Publication No. 10-2012-0048692 (published on May 15, 2012)

SUMMARY OF THE INVENTION An object of the present invention is to provide a reactor laser pinning apparatus capable of easily improving stress even from a welded portion formed around a region where an outermost nozzle penetrates the inner spherical surface of the reactor.

Another object of the present invention is to provide a reactor laser peening apparatus capable of actively performing a laser peening operation in accordance with different shapes and conditions of welds formed on the inner spherical surface of a nuclear reactor.

Another object of the present invention is to provide a reactor laser peening apparatus capable of performing a laser peening operation smoothly close to all welds formed at different positions on the inner spherical surface of a reactor.

In order to achieve the above object, according to the present invention, there is provided a laser beam peening apparatus for a reactor for repairing a weld formed around an outermost nozzle of a reactor inner spherical surface, the apparatus comprising: a laser irradiation unit; And a transferring unit for moving the laser irradiation unit to a welded portion, wherein the laser irradiation unit rotates along an inner circumferential rail provided at an inner periphery of the reactor toward a nozzle to be repaired, and the flow baffle and the flow baffle And a transfer driving unit for moving the laser irradiating unit up and down so as not to interfere with the inner ring and moving the laser irradiating unit back and forth in the radial direction of the reactor at the elevated position so as to approach the weld.

Here, the laser irradiation unit preferably includes a laser oscillator for generating a laser beam.

The laser irradiating unit includes a light guide portion having a plurality of mirrors therein so as to guide the irradiation direction of the laser beam generated in the laser oscillator, and a light guide portion guided by the light guide portion, It is preferable to further include a light irradiating part provided to be irradiated.

The laser irradiation unit may further include an optical tilting driving unit configured to rotate the light irradiating unit such that an irradiation angle of the laser beam by the light irradiating unit is variable.

The laser irradiation unit may further include a profile scanner provided to measure a shape of a weld formed on an inner spherical surface of the reactor.

The laser irradiating unit may further include a controller for controlling the optical tilting driver based on the shape of the welded portion measured through the profile scanner.

According to another aspect of the present invention, there is provided a laser irradiation unit of a laser pinning apparatus for repairing a weld formed on an inner spherical surface of a reactor, the laser irradiation unit comprising: a laser oscillator for generating a laser beam; A light guiding part having a plurality of mirrors provided therein so as to guide the irradiation direction of the laser beam generated from the laser oscillator; And a light irradiating part which is guided by the light guiding part and is arranged so that the incident laser beam is collected and irradiated in one direction.

The laser irradiation unit of the laser pinning apparatus according to the present invention may further include an optical tilting driving unit configured to rotate the light irradiating unit such that an irradiation angle of the laser beam by the light irradiating unit is variable.

The laser irradiation unit of the laser peening apparatus may further include a profile scanner configured to measure a shape of a weld formed on an inner spherical surface of the reactor.

The laser irradiation unit of the laser pinning apparatus may further include a scanner tilting driving unit configured to rotate the profile scanner so that the scanning angle of the profile scanner varies.

According to the present invention, it is possible to provide a reactor laser peening apparatus capable of easily improving the stress even from the inner spherical surface of the reactor to the welded portion formed around the region where the outermost nozzle penetrates.

Also, by providing a profile scanner, it is possible to provide a reactor laser peening apparatus capable of actively performing a laser peening operation in accordance with different shapes and conditions of welds formed on the inner spherical surface of a reactor.

In addition, it is possible to provide a reactor laser peening apparatus capable of performing a laser peening operation smoothly close to all the welding portions formed at different positions on the inner spherical surface of the reactor.

Further, the laser peening apparatus of a nuclear reactor capable of precisely improving the stress even at the welded portion formed at the position where the inclination degree is relatively high at the inner spherical surface of the reactor by changing the irradiation angle of the laser beam by the optical tilting drive unit can be provided.

Further, the laser irradiation unit is driven by the feed driving unit so as to be driven at three degrees of freedom, that is, front and rear horizontal driving, up / down driving, and rotary driving so that interference due to structures such as flow baffle and flow baffle inner ring disposed inside the reactor occurs It is possible to provide a reactor laser pinning apparatus capable of easily performing the laser pinning work by avoiding such interference.

Furthermore, since the optical tilting drive unit is controlled by the control unit, it is possible to provide a laser pinning apparatus for a nuclear reactor capable of automatically and conveniently performing a laser peening operation.

1 is a perspective view showing a state where a laser pinning apparatus according to the present invention is applied to a nuclear reactor,
Fig. 2 is a perspective view of the laser irradiation unit of Fig. 1,
FIG. 3 is a diagram showing a configuration of a light irradiating unit and an optical tilting driving unit provided below the laser irradiation unit of FIG. 2;
FIG. 4 is a side view showing an operating state in which the light irradiation unit is tilted by the optical tilting driving unit of FIG. 3,
FIG. 5 is a diagram showing a profile scanner and a scanner tilting driving unit provided at a lower portion of the laser irradiation unit of FIG. 2;
FIG. 6 is a side view showing an operating state in which the profile scanner is tilted by the scanner tilting driving unit of FIG. 5;
7 is a control block diagram of a laser pinning apparatus according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the laser pinning apparatus 10 for a reactor according to the present invention is provided in a pressurized water reactor 1 having a lower portion formed in a spherical shape so as to repair welds formed on the inner spherical surface of the reactor 1 A conveying unit 40 that is conveyed along the inner circumference rail 20 and a conveying unit 40 that is provided in the conveying unit 40. The conveying unit 40 includes a conveying unit 40, A radial rail 30 provided to guide the transfer of the laser beam 1 in the radial direction of the reactor 1 and a laser beam And a laser irradiating unit (50) adapted to irradiate the laser beam with a changing angle of the laser beam by a tilting drive according to the shape of the welded portion.

Accordingly, it is possible to efficiently perform a laser peening operation that smoothly comes close to all the welding portions formed at different positions on the inner spherical surface of the reactor 1, thereby making the low tensile stress of each welding portion high compressive stress, It is possible to provide a reactor laser pinning apparatus 10 capable of easily performing stress repairing even to a welded portion formed around the portion where the outermost nozzle penetrates from the inner spherical surface of the reactor 1.

As shown in FIG. 1, when the lower part of the reactor 1 is formed into a sphere, a plurality of BMI (bottom mounted instrument) nozzles are installed in the lower inner spherical surface so as to be exposed to the outside, A weld is formed around the inner spherical surface by filling the groove with a welding operation.

Since the welding portions are formed in spherical surfaces at the lower portion of the reactor 1, welds formed at different positions are formed to be different from each other, and welding portions formed around the outermost nozzles among the nozzles are formed inside the reactor 1 And a structure such as a flow baffle 3 and a flow baffle inner ring 5 is installed on the upper portion. The inner peripheral rail 20 according to the present invention is installed on the upper portion of the flow baffle inner ring 5.

The transfer unit 40 is coupled to the inner rail 20 and the radial rail 30 so as to be slidably conveyed along the inner rail 20 and the radial rail 30, Unit 50 is coupled.

2, the laser irradiating unit 50 includes a laser oscillator 60 for generating a laser beam, a laser oscillator 60 for generating a laser beam from the laser oscillator 60, And a feed drive unit 53 which is provided to be irradiated by a feed with three degrees of freedom such as up-down lift driving and rotary drive.

The light irradiating unit 65 connected to the light guiding unit 61 of the laser irradiating unit 50 to be described later is moved forward and backward along the inner rail 20 and the radial rail 30 by the feed driving unit 53 Even if interference is caused by structures such as the flow baffle 3 and the flow baffle inner ring 5 disposed inside the reactor 1 due to being provided to be driven at three degrees of freedom such as horizontal drive, It is possible to provide a laser pinning apparatus 10 of a nuclear reactor capable of easily avoiding interference and performing laser peening work on a welded portion.

2, the laser oscillator 60 of the laser irradiation unit 50 is provided inside the unit casing 51, and the feed drive part 53 is provided in the unit casing 51 As shown in Fig.

2, the feed driving section 53 includes a front and rear driving motor 53a provided so as to feed the light guide section 61 in the forward and backward horizontal directions, And a rotation drive motor 53c provided so that the light guide portion 61 is rotatably transported.

2 and 3, the light irradiating unit 65 connected to the light guiding unit 61 of the laser irradiation unit 50 by the feed driving unit 53 performs the front-back horizontal driving, the vertical lift driving, And rotational drive.

In the embodiment of the present invention, the front and rear drive motor 53a is provided to drive the conveyance of approximately 50 mm, the elevation drive motor 53b is provided to drive the elevation of approximately 565 mm, May be provided to drive rotation of about 370 degrees.

3, the laser irradiation unit 50 is provided with a plurality of mirrors 63 disposed so as to face each other in an inclined manner so as to guide the irradiation direction of the laser beam generated in the laser oscillator 60 And a light irradiating unit 65 provided with a focusing lens such that the laser beam guided and guided by the light guiding unit 61 is gathered and irradiated in one direction.

Thereby, the laser beam generated in the laser oscillator 60 is guided by refraction and reflection in the mirrors 63 of the light guide portion 61, is condensed in the light irradiation portion 65, The path of the laser beam can be guided to be changed through the light guide portion 61 as much as possible.

2 and 3, the laser irradiation unit 50 is configured to rotate the irradiation unit 65 such that the irradiation angle of the laser beam by the irradiation unit 65 is varied And an optical tilting driving unit 70 provided as a motor.

4, the irradiation angle of the laser beam is changed by the optical tilting driving unit 70 so as to be changed in tilting rotation, so that the welded portion formed at the position where the inclination degree is relatively high in the inner spherical surface of the reactor 1 It is possible to provide a laser pinning apparatus 10 of a reactor capable of precisely performing stress repairing.

In addition, the light irradiating unit 65 can be tilted and rotated by the optical tilting driving unit 70 so that the laser beam is irradiated to the welded portion with the optimum focal distance according to the shape of the J-groove around the nozzle.

A tilting drive unit including a reduction gear, a worm gear, and the like may be provided between the optical tilting drive unit 70 and the light irradiation unit 65.

2 and 5, the laser irradiation unit 50 further includes a profile scanner 80, which is provided to measure the shape of the weld formed on the inner spherical surface of the reactor 1 .

6, there is provided a profile scanner 80 which is rotated in a tilting manner so as to measure the shape of the welded portion at a plurality of angles, so that the welded portions formed on the inner spherical surface of the reactor 1 have different shapes and conditions It is possible to provide the laser pinning apparatus 10 of the reactor in which the laser pinning operation can be actively performed.

The profile scanner 80 is preferably tilted and rotated by a scanner tilting drive unit 81 provided with another motor and a separate transfer means is also provided between the scanner tilting drive unit 81 and the profile scanner 80 . That is, the laser irradiation unit 50 may further include a scanner tilting driving unit 81 configured to rotate the profile scanner 80 such that the scanning angle of the profile scanner 80 is variable.

Although not shown, it goes without saying that the respective driving parts of the laser irradiation unit 50 according to the present invention are operated by a power source connected to the respective driving parts and supplied from the power source part.

2, a nozzle clamp 55 is provided on the lower portion of the unit casing 51 of the laser irradiation unit 50 so as to be in parallel with the light guide portion 61. As shown in FIG.

Thus, the nozzle clamp 55 is lowered and fixed to the upper portion of the nozzle at the center of the welding portion where the pinning operation is performed, so that the laser irradiation unit 50 is fixed to the nozzle by the nozzle clamp 55, The laser peening operation can be performed stably.

7, the laser irradiation unit 50 includes a control unit 70 for controlling the optical tilting driving unit 70 based on the shape of the welded portion measured through the profile scanner 80, (90).

Accordingly, the optical tilting driving unit 70, the laser oscillator 60, and the scanner tilting driving unit 81 are controlled by the control unit 90 that receives the measurement result from the profile scanner 80, It is possible to provide a reactor laser pinning apparatus 10 that can be conveniently performed.

Thus, according to the present invention, it is possible to provide a reactor laser pinning apparatus (10) capable of easily performing stress repairing even to a welded portion formed around a portion where an outermost nozzle penetrates from an inner spherical surface of the reactor (1).

Although the present invention has been described in detail with reference to the above embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

20: inner peripheral rail 30: radial rail
40: transfer part 50: laser irradiation unit
53: feed drive part 60: laser oscillator
61: light guide portion 63: mirror
65: light irradiating unit 70: optical tilting driving unit
80: profile scanner 90:

Claims (12)

A laser pinning apparatus for a reactor for repairing a weld formed around an outermost nozzle of an inner spherical surface of a reactor (1)
A laser irradiation unit (50); And
And a transfer unit (40) for transferring the laser irradiation unit (50) to a welded portion,
The laser irradiation unit (50)
The laser irradiating unit is rotated around the nozzle to be repaired along the inner circumference rail 20 provided at the inner periphery of the reactor 1 so as not to interfere with the flow baffle and the flow baffle inner ring of the inner surface of the reactor 1, And a transfer driving unit (53) for moving the laser irradiating unit (50) up and down in the radial direction of the reactor to move the laser irradiating unit (50) back and forth in the radial direction of the reactor. The method according to claim 1,
The laser irradiation unit (50)
And a laser oscillator (60) for generating a laser beam. 3. The method of claim 2,
The laser irradiation unit (50)
A light guiding part 61 having a plurality of mirrors 63 provided therein so as to guide the irradiation direction of the laser beam generated from the laser oscillator 60,
Further comprising a light irradiating unit (65) arranged to irradiate the laser beam guided and guided by the light guiding unit (61) in one direction. The method of claim 3,
The laser irradiating unit 50 includes an optical tilting driving unit 70 configured to rotate the light irradiating unit 65 such that an irradiation angle of the laser beam by the light irradiating unit 65 is varied. / RTI > 5. The method of claim 4,
Wherein the laser irradiation unit (50) further comprises a profile scanner (80) arranged to measure a shape of a weld formed on an inner spherical surface of the reactor (1). 6. The method of claim 5,
The laser irradiating unit (50) further includes a controller (90) for controlling the optical tilting driver (70) based on the shape of the welded portion measured through the profile scanner (80) Device. delete delete delete delete The method according to claim 1,
Further comprising a radial rail (30) for guiding the transferring unit (40) to be transferred in the radial direction of the reactor (1) to the transferring unit (40). The method according to claim 1,
Further comprising a nozzle clamp (55) that is lowered by a nozzle of a welding portion where a pinning operation is performed and is closely fixed to an upper portion of the nozzle, below the laser irradiation unit (50).

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