JPH06155172A - Wire peening gun and wire peening device and wire peening method for structure in nuclear reactor - Google Patents

Abstract

PURPOSE:To prevent stress corrosion crack by providing a wire holding part for holding a plurality of fine wires of required diameter or less in an implanting condition and a vibration means for vibrating this wire holding part in a direction of implanting the wire, so as to improve tension residual stress into compression residual stress. CONSTITUTION:A peening gun 1 is constituted of a vibrator 21, peening rod 21, peening rod 22, suction pipe 23, oscillating mechanism 24 and a coupler 25 and engaged with a flexing arm by the coupler 25. The peening rod 22 is vibrated in the same direction to a lengthwise direction of the peening gun 1, and an internal peripheral surface of a shroud is peened by a plurality of fine wire heads 26 of 2mm or less diameter connected to a point end of the peening rod 22. Since scale and deposition or the like are separated from a surface according to peening, to stain reactor water to form turbid water by foreign matter, this water is sucked by the suction pipe 23, guided to a separation purifier in the outside of a pressure vessel by a water suction hose and here processed to separate the foreign matter, and the reactor water is purified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving the tensile residual stress existing on the surface of a general metallic material and the surface layer of equipment in a nuclear reactor, in which a wire bundle is made to collide with the surface of the material in water. The present invention relates to a wire pinning gun, a wire pinning apparatus, and a wire peening method for a reactor internal structure, which are suitable for forming a compressive residual stress in a surface layer to improve the surface stress.

[0002]

2. Description of the Related Art Austenitic stainless steel SUS3
The internal structure equipment and primary system equipment of the 04 steel nuclear reactor may cause intergranular cracking type stress corrosion cracking (hereinafter abbreviated as IGSCC) near the welded portion during use. Is commonly known. IGSCC occurs only under the condition in which the three factors of sensitization of weld, tensile stress and corrosive environment are superposed.

Sensitization of materials occurs by the heat of welding.
Due to the welding heat, Cr carbide is precipitated at the grain boundaries, so that Cr-deficient portions are formed in the immediate vicinity of the grain boundaries, and the Cr-deficient portions are easily corroded (called sensitization). The tensile stress is generated by an external force, and the tensile residual stress generated by welding or working is superposed on the tensile stress, resulting in a high tensile stress state. Usually, the contribution of tensile residual stress to the stress factor is extremely large. The corrosive environment is the reactor water itself, and if dissolved oxygen is contained, the corrosive environment becomes even more severe. IG
SCC can be prevented by removing any one factor from the superposition of these three factors, and improving tensile residual stress to compressive stress is an effective preventive maintenance measure for IGSCC prevention.

As a means for improving the residual stress of nuclear equipment, there is a method relating to peening, which is disclosed in Japanese Patent Laid-Open No. 62-6.
There is a technique described in Japanese Patent No. 3614. In this technique, a high-pressure water jet device having a rotating nozzle unit for ejecting a high-pressure liquid jet is inserted inside a pipe such as a heat exchanger, which is an object of residual stress improvement, and the collision dynamic pressure energy of the jet (jet jet flow Axial kinetic energy is used to apply tensile plastic deformation to the inner surface layer of the pipe to reduce the residual tensile stress originally present in the pipe.

The above-mentioned prior art is an effective method for improving the residual stress on the inner surface of a pipe such as a heat exchanger, but this method applies a liquid jet ejected from a nozzle to the surface of a metal member in the atmosphere. This technique uses the collision energy to pin the above, and this technique uses the collision dynamic pressure of the water jet in the atmosphere and relies only on the jet pressure of the water jet. Is the way. There are the following problems when this technique is applied to the reactor internal equipment of a submerged nuclear reactor.

[0006]

When utilizing this technique in water, the resistance of the ambient water to the water jet reduces the flow velocity of the water jet, causing the water jet to lose its surface at the metal surface. The collision dynamic pressure becomes low, and it becomes difficult to effectively obtain the pinning effect. Therefore, in order to obtain a dynamic pressure equivalent to that of the jet in the atmosphere, water jet injection at ultrahigh pressure is required, and ultrahigh pressure pumps and piping are required, leading to cost increase.

As another conventional technique, hammer peening is a well-known technique that has been used in the industry for a long time. Residual stress can be improved by hammer peening. However, considering that the target equipment is SUS304 stainless steel, it cannot be applied to the equipment inside the reactor. The reason is that in SUS304 stainless steel, if excessively strong cold working such as hammer peening is applied, work-induced martensitic transformation occurs, resulting in deterioration of corrosion resistance.

An object of the present invention is a wire pinning gun which is suitable for improving the tensile residual stress of the internal equipment of a nuclear reactor which is already in operation and is submerged in water or the member surface of a general metallic material into a compressive residual stress. The present invention relates to a wire peening apparatus and a wire peening method for a reactor internal structure.

[0009]

To achieve the above object, the present invention provides a plurality of fine wire wires having a diameter of 2 mm or less, and a wire holding portion for holding the plurality of fine wire wires in an upright state.
This is a wire peening gun including a vibrating means for vibrating the wire holding portion in the direction of raising the wire. In this wire peening gun, a unit composed of the thin wire and the wire holding portion is provided on one side surface of the vibrating means main body, and a reaction force rod receiving a reaction force of peening on the side surface of the vibrating means main body opposite to the unit. Is preferably provided, or a unit including the thin wire and the wire holding portion is provided on one side surface of the vibrating means main body and an opposite side surface which is symmetrical to the one side surface.

Further, in the wire peening gun, it is preferable that a plurality of units each including the thin wire and the wire holding portion are arranged in parallel. Further, it is preferable that a swing means for swinging the vibrating means main body is provided at a base end portion of the vibrating means. Further, it is preferable that a suction pipe connected to a suction hose is provided so as to surround the vibrating means and the wire holding portion in a state where the thin wire side is opened.

Further, the present invention is a wire peening apparatus comprising a moving means for moving the tip portion three-dimensionally and the wire peening gun according to any one of the above, which is provided at the tip portion of the moving means. is there.

According to the present invention, a long mast which is movable in the axial direction, a bending arm which is provided at a lower end portion of the mast and opens and closes in an umbrella shape, and any one of the above described which is provided at a tip of the bending arm. And a wire peening gun. Here, the base end part of the mast is mounted on the flange surface of the reactor pressure vessel and is movable in the circumferential direction of the pressure vessel, and the swivel table is provided to move in the radial direction of the reactor pressure vessel. It is preferable that the movable mast is equipped with a movable carriage to which the base end of the mast is attached.

The present invention also relates to a wire peening method for the internal structure of a nuclear reactor, comprising the steps of removing the upper lid of the reactor pressure vessel, the steam dryer, the steam separator and the fuel channel in this order, and the pressure. Mounting the swivel base of the wire peening apparatus according to claim 8 on the flange surface of the container;
Using the wire peening device, in a state of being filled with reactor water, while peening with a peening gun in accordance with the surface shape of the peening target, suction the foreign matter clouded reactor water in the vicinity of the peening portion with the suction pipe, outside the furnace It is characterized by including the steps of discharging, separating and collecting foreign matter from the discharged water, purifying the discharged water, and performing construction while monitoring the peening condition and the foreign matter turbidity reactor water suction condition with a monitoring camera.

[0014]

According to the present invention, the diameter is 2 mm or less, preferably 1.
Since the object to be treated is peened with a bundle of fine wire wires implanted in the shape of a metal brush of mm or less, the impact of peening is not too strong and not too weak because of the fine wire, and peening with optimum strength is possible. Therefore, it is possible to generate only the compressive residual stress for a large area without generating processed martensite.

Further, by providing the peening gun with a plurality of peening rods each having a wire bundle, the peening effect on the curved surface portion can be enhanced.

Further, the peening rod extended in the direction orthogonal to the longitudinal direction of the babulator which is the vibrating means can reduce the required space distance in the reciprocating direction of the peening rod. Therefore, the peening of the narrow space becomes possible.

According to the wire peening apparatus and method of the present invention, the upper lid of the nuclear reactor is moved by the bending action of the three-dimensional moving means, that is, the remote three-dimensional drive unit and the bending arm at the tip thereof and the swinging action of the peening gun. With the steam dryer, steam separator, and fuel channel simply removed, the peening target equipment such as the shroud and upper lattice plate can be removed without peening. In addition, the foreign matter suction / collection device can suction the foreign matter such as surface deposits and scales that have been unavoidably generated during the peening process and that have separated from the construction surface with the reactor water, and collect the foreign matter outside the furnace. It has a function to separate into reactor water and purify and reuse the separated reactor water.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing the apparatus configuration of this embodiment. The peening guns 1a and 1b are bent arms 2a and 2
The bending arms 2a and 2b are attached to the mast 3, respectively, and the mast 3 is engaged with the three-dimensional drive device 4 and the three-dimensional drive device 4 is provided on the swivel base 5. The bending arm 2 has an opening / closing function like an umbrella by a joint mechanism, and the opening / closing angle is 0 to 360 degrees. The mast 3 can be moved up and down in the axial direction of the pressure vessel 6, and is engaged with the three-dimensional drive device 4 so that the mast 3 itself can rotate. The three-dimensional drive device 4 is placed on a swivel base 5 so as to be movable in the radial direction of the pressure vessel 6. Further, the three-dimensional drive device 4 itself travels on the swivel base 5 in the radial direction, and ascends and descends and rotates the mast 3 to enable remote four-dimensional drive. The swivel base 5 is provided on the flange base 7 so as to swivel.
The flange base 7 is set on the flange 6-1 of the pressure vessel 6.

The working air is sent from the compressor 9 to the peening gun 1 through the air tube 8. Furthermore, the peening gun 1 is connected to a suction hose 11 for sucking foreign matter mixed with the reactor water, and is connected to a suction pump 12. The foreign matter-containing reactor water sucked up by the suction pump 12 is guided to the separation and purification device 13, where the foreign matter and the reactor water are separated, and the reactor water is further purified,
It is returned to the pressure vessel 6. The separation / purification device 13 is composed of a filter and an ion exchange resin.

In FIG. 1, the upper lid of the reactor pressure vessel, the steam dryer, the steam separator, the fuel channel, and the control rod are removed in this order, and the flange base 7 on the surface of the flange 6-1 of the pressure vessel 6 is swung. The table 5 and the three-dimensional drive 4 are attached in this order, and the mast 3 is lowered through the grid 14-1 of the upper lattice plate 14 to the core portion 15 with the bending arm 2 closed, and at this position, the bending arm 2a 2b is opened, and the peening guns 1a and 1b are vertically pressed against the wall surface of the shroud 16 to perform wire peening. In this state, by moving the mast 3 up and down, the movement peening of the shroud 16 in the axial direction of the inner peripheral surface can be performed,
By rotating the mast 3, movement peening of the shroud 16 in the circumferential direction of the inner peripheral surface can be performed. Bending arm 2
By making the opening angle of a and 2b obtuse, the peening of the corner portion of the boundary between the upper lattice plate 14 and the shroud 16 becomes possible, and by making the opening angle of the bending arms 2a and 2b acute, the shroud 16 and The peening of the corner portion of the boundary of the core support plate 17 becomes possible. Bending arm 2
The arm lengths of a and 2b can be freely adjusted according to the opening / closing angle.

FIG. 2 shows another embodiment of the peening gun 1.
In order to receive the peening reaction forces of a and 1b, the tip ends of the bending arms 2a and 2b are branched, and the peening guns 1a and 1b are provided in one of the branches and the reaction force receiving 18 is provided in the other of the branches.
a and 18b are provided. The reaction force receivers 18a and 18b can secure stability against radial vibration of the mast 3 by pushing the shroud 16 via the rolling indenters 19a and 19b. Therefore, the construction reliability of the peening work is secured. Further, the CCD cameras 20a and 20b are attached to the mast 3 toward the peening construction portion, whereby peening construction monitoring can be performed. Although attached to the mast 3 in this example, the bending arm 2a,
It may be attached to 2b.

3 and 4 are side views showing the details of one embodiment of the peening gun 1 according to the present invention. The peening gun 1 includes a vibrator 21 and a peening rod 2.
2, suction pipe 23, swing mechanism 24, and coupler 25
The coupler 25 is engaged with the bending arm 2.
The peening rod 22 is vibrated in the same direction as the longitudinal direction of the peening gun 1, and the fine wire wire head 26 connected to the tip of the peening rod 22 peens the inner peripheral surface of the shroud 16 of FIGS. 1 and 2. As peening causes scales and stagnant substances on the surface to peel off, foreign matter pollutes the reactor water and becomes turbid water, which is sucked by the suction pipe 23 and separated from the outside of the pressure vessel 6 by the suction hose 11. It is led to the purifying device 13, where foreign matter is separated and treated, and the reactor water is purified and returned to the pressure vessel 6 to be reused as reactor water. Therefore, the waste is only solid and does not generate wastewater. In the wire head 26 detachably engaged with the tip of the peening rod 22, a fine wire 27 having a diameter of 1 mm is implanted in the shape of a metal brush, as shown in an enlarged view in FIG.

FIG. 5 is a side view showing another embodiment of the peening gun 1 according to the present invention. In this example, a plurality of peening rods 22-1, 22-2, 22-3 ... Are engaged with the vibrator 21, and each peening rod 2
At the tip of 2, the thin wire 27-1, 27-2, 27-
3 ... is directly implanted in the shape of a metal brush. According to this embodiment, a plurality of peening rods 22-1, 2
.. can be peened independently of each other, so that peening can be performed uniformly and surely on the curved construction surface.

Further, as a modification of FIG. 5, the number of peening rods 22-1, 22-2, 22-3 ... Is 10.
Alternatively, the diameter of the peening rod may be reduced to 100, and the diameter of the peening rod may be made smaller, and a wire-shaped fine wire may be directly engaged with the vibrator 21 to form a peening gun. According to this embodiment, since each thin wire operates independently, peening can be performed uniformly and surely on a construction surface having a complicated curved surface shape without leaving a hit.

FIG. 6 is a side view showing another embodiment of the peening gun 1 according to the present invention. In this example, the wire heads 26-1, 26-2, in which a plurality of fine wires 27-1, 27-2, ... Are implanted in the shape of a metal brush, are the peening rods 22-1, 22-2. And the peening rods 22-1, 22-2 ...
It is engaged with the vibrator 21 so as to be orthogonal to the longitudinal direction of the vibrator 21 via a swing mechanism 24 and a spacing piece 28 which is a spacer for adjusting the spacing. A reaction force rod 29 that receives a reaction force of peening is provided in a direction opposite to this. The reaction force rod 29 is provided with a rotatable rotor 29-1 at its tip and is engaged with the vibrator 21 via a spacing piece 29-2 for spacing adjustment. According to this embodiment, since the distance between the rotor 29-1 and the thin wire 27 can be shortened, the shroud 16 and the pressure vessel 6
Peening can be done in narrow spaces such as between and. It is preferable to adjust the spacing pieces 28 and 29-2 according to the clearance.

FIG. 7 is a side view showing another embodiment of the peening gun 1 according to the present invention. In FIG. 7, FIG.
Another peening rod is provided instead of the reaction force rod 29 of FIG. According to this embodiment,
The reaction force of peening is self-balanced, and the opposing parts can be peened simultaneously, resulting in high efficiency. That is, it is suitable for peening both surfaces in the narrow portion such as between the shroud 16 and the pressure vessel 6.

The above-mentioned embodiment is applied to the shroud, but by inserting the mast 7 into any lattice hole of the upper lattice plate, the lower plate portion of the lattice plate and the core support plate can be constructed. If the mast 7 is pulled out from the lattice hole, it can be installed on the upper surface of the lattice plate.

[0028]

According to the present invention, it is possible to easily improve the residual stress of the existing reactor pressure vessel internal structure from tension to compression, and to prevent stress corrosion cracking of the reactor pressure vessel internal structure. Can be prevented. In addition, since the peening gun can be moved three-dimensionally and remote construction can be performed while the reactor water is being filled, it is possible to reduce the exposure dose of the worker during peening construction. Since the scale on the construction surface can be peeled off, the reactor water is purified. Further, the present invention can be applied to any of a tubular device having a large space space, a narrow portion, a corner curved surface and a concave curved surface.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an overall configuration of a wire peening apparatus for improving a residual stress of a reactor internal structure according to an embodiment of the present invention and a partial sectional view showing a core shroud application state.

FIG. 2 is an overall configuration diagram of a wire peening apparatus with a reaction force receiver for improving residual stress of a reactor internal structure according to another embodiment of the present invention and a configuration diagram showing a part of a core shroud application state in a sectional view. Is.

FIG. 3 is a side view showing a peening gun according to an embodiment of the present invention.

FIG. 4 is a side view showing a peening gun according to another embodiment of the present invention.

FIG. 5 is a side view showing a multiple peening rod according to another embodiment of the present invention.

FIG. 6 is a side view showing a peening gun according to another embodiment of the present invention.

FIG. 7 is a side view showing a peening gun according to another embodiment of the present invention.

[Explanation of symbols]

 1 peening gun 2 bending arm 3 mast 4 three-dimensional drive device 5 swivel table 6 pressure vessel 11 suction hose 12 suction pump 13 separation purification device 18 reaction force receiver 20 CCD camera 21 vibration means (vibrator) 22 peening rod 23 suction pipe 24 neck Swing mechanism 26 Wire head 27 Fine wire 29 Reaction rod

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunio Enomoto, Kunio Enomoto, 502 Jinritsucho, Tsuchiura-shi, Ibaraki Machinery Research Laboratory, Hiritsu Seisakusho Co., Ltd. (72) Koichi Kurosawa 3-1-1, Sachimachi, Hitachi, Ibaraki Company Hitachi, Ltd.Hitachi factory (72) Inventor Masato Mochizuki 502 Jintamachi, Tsuchiura-shi, Ibaraki Prefecture Hiritsu Works Co., Ltd.Mechanical Research Institute (72) Masahiro Otaka 502 Kintate-cho, Tsuchiura-shi, Ibaraki Hitsuritsu Co., Ltd. (72) Inventor Shinji Sakata 502 Jinritsucho, Tsuchiura-shi, Ibaraki Prefecture Hiritsu Seisakusho Co., Ltd. (72) Inventor Makoto Hayashi, 502 Kintatecho, Tsuchiura-shi, Ibaraki Hiritsuteki Co., Ltd. (72) Inventor Eisaku Hayashi 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Yoshi Coercive Fujio Hitachi City, Ibaraki Prefecture Saiwaicho Third Street No. 2 No. 2 Hitachi Men u clear Engineering Co., Ltd. in

Claims (10)

[Claims] 1. A plurality of fine wire wires having a diameter of 2 mm or less,
A wire peening gun comprising: a wire holding portion that holds the plurality of thin wire wires in a standing state, and a vibrating means that vibrates the wire holding portion in a direction in which the wires are standing. 2. The wire peening gun according to claim 1, wherein a unit composed of the thin wire and the wire holding portion is provided on one side surface of the vibrating means body, and a side surface of the vibrating means body opposite to the unit. A wire peening gun characterized in that a reaction force rod for receiving a reaction force of peening is provided on the. 3. The wire peening gun according to claim 1, wherein a unit including the thin wire and a wire holding portion is provided on one side surface of the vibrating means main body and an opposite side surface which is symmetrical to the one side surface. A wire peening gun characterized by that. 4. The wire peening gun according to any one of claims 1 to 3, wherein a plurality of units each including the thin wire and the wire holding portion are arranged in parallel. 5. The wire peening gun according to any one of claims 1 to 4, wherein a swinging means for swinging the swinging means main body is provided at a base end portion of the swinging means. Wire peening gun. 6. The wire peening gun according to claim 1, wherein a suction pipe connected to a suction hose is provided so as to surround the vibrating means and the wire holding portion with the thin wire side open. A wire peening gun that has been characterized. 7. A wire peening apparatus comprising a moving means for moving the tip part three-dimensionally, and the wire peening gun according to claim 1 provided at the tip part of the moving means. . 8. A long mast that is movable in the axial direction, a bending arm that is provided at the lower end of the mast and opens and closes like an umbrella, and a bending arm that is provided at the tip of the bending arm. And a wire peening gun according to claim 1. 9. The wire peening apparatus according to claim 8, wherein a base end portion of the mast is mounted on a flange surface of the reactor pressure vessel, and is a swivel base movable in the circumferential direction of the pressure vessel; A wire peening apparatus, comprising: a movable carriage that is provided on a base and is movable in a radial direction of a reactor pressure vessel and to which a base end portion of the mast is attached. 10. A method for wire peening a reactor internal structure, comprising: removing a reactor pressure vessel upper lid, a steam dryer, a steam separator, and a fuel channel in this order;
A step of placing the swivel base of the wire peening apparatus according to any one of claims 7 to 9 on a flange surface of this pressure vessel, and a peening target in a state of being filled with reactor water using the wire peening apparatus. While peening with a peening gun to match the surface shape of the, suction the foreign matter cloudy reactor water in the vicinity of the peening part with the suction pipe, discharge it out of the furnace, separate the foreign matter from the discharge water, perform recovery and purification of the discharge water, A wire peening method for a reactor internal structure, which comprises a step of performing construction while monitoring a peening condition and a foreign matter turbidity reactor water suction condition with a surveillance camera.