JP4043668B2 - Surface processing equipment for in-reactor installation equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface processing apparatus for in-reactor installation equipment to be applied to an austenitic stainless steel which is a constituent material of an in-core monitor guide tube and an in-core monitor housing for the purpose of preventive maintenance of structures inside the reactor.
[0002]
[Prior art]
The reactor internal structure is composed of materials with sufficient corrosion resistance and high-temperature strength, such as austenitic stainless steel, but there are concerns about material degradation due to long-term operation under high temperature and pressure and neutron irradiation. Yes. Especially in the vicinity of the welded part of the furnace internal structure, there is a possibility of potential stress corrosion cracking (hereinafter referred to as SCC) due to material sensitization and tensile residual stress formed by welding heat input. Yes.
[0003]
Shot peening is an effective technique for preventive maintenance of the above SCC. Metal spheres (shots) are projected at high speed with high-pressure air, etc., and the kinetic energy is used to plastically deform the material surface to compress the tensile residual stress. By changing to stress, the stress factor (tensile residual stress during welding), which is one of the three SCC factors (material, environment, and stress), is removed to prevent the occurrence of SCC near the weld.
[0004]
It is desirable to perform shot peening in the air in parallel with the replacement work of the in-reactor structure for the parts such as the in-core monitor guide tube at the bottom of the reactor which is difficult for workers to access during regular periodic inspection.
[0005]
In this case, the shot is projected with high-pressure air, the shot injection device is installed on the template temporarily installed in the reactor pressure vessel, and the narrow section below the in-core monitor guide tube where the worker stands from above the temporary reactor bottom shield The shot peening is performed near the welded part with the in-core monitor housing.
[0006]
[Problems to be solved by the invention]
However, since the worker takes an unreasonable posture to lean down, it is difficult to accurately position the peening head at the construction site, and it takes time to grasp and move the construction position, so the construction time becomes long. There are challenges.
[0007]
In addition, although the reactor pressure vessel is cleaned during construction, the reactor structure itself is slightly activated and some radioactive materials that cannot be removed by cleaning remain, so the reactor pressure vessel inside the work site The bottom becomes a radiation environment, and there is a problem that the exposure dose of workers increases as the construction time becomes longer.
[0008]
The present invention has been made in order to solve the above-described problems. An atom that can be accurately positioned even in a narrow portion below the in-core monitor guide tube that stands in the forest, shortens the construction time, and reduces the radiation exposure dose of the worker. The object is to provide a surface processing apparatus for in-furnace installation equipment.
[0009]
[Means for Solving the Problems]
The invention of claim 1 is a surface processing apparatus for in- reactor installation equipment that performs shot peening in the air in the vicinity of a welded portion between an in-core monitor guide tube and an in-core monitor housing that stands on the bottom of the reactor. The processing apparatus includes an apparatus main body supported by a clamp mechanism fixed to the in-core monitor guide tube via a handle, a positioning mechanism fixed to the apparatus main body and positioned by contacting the upper surface of the CRD housing, and the apparatus A peening head mechanism that is attached to the main body so as to be movable up and down by a lifting mechanism and a turning mechanism and jets a shot, and a shot collection device that collects the shot is provided .
[0010]
According to the first aspect of the present invention, shot peening can be performed in the vicinity of an arbitrary welded portion of a narrow portion composed of an in-core monitor guide tube and an in-core monitor housing that stands on the inner bottom of the reactor, and a head lifting mechanism and a turning mechanism Since each can be operated independently, the apparatus can be miniaturized.
[0011]
Moreover, since each mechanism and apparatus can be operated simultaneously, the shot peening construction speed is doubled compared with the single operation, and construction time can be shortened. Furthermore , shot injection , recovery, turning, and raising / lowering can be performed by a series of operations. Therefore, the operation load on the worker can be reduced, the construction time can be shortened, and the radiation exposure can be reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a surface processing apparatus for in-reactor installation equipment according to the present invention will be described with reference to FIGS.
FIG. 1 shows a state in which the surface processing apparatus 8 shown in FIGS. 2 and 3 according to the present embodiment is installed in the reactor pressure vessel 1 to perform the surface processing operation. FIG. 2 is an enlarged view of the surface processing apparatus 8 according to the present embodiment, and shows an enlarged view of a state in which the welded portion 51 of the in-core monitor guide tube 3 is installed in the CRD housing 5 and shot peened. 3 is a top view of the lid 27 for closing the upper end opening of the apparatus main body 26 in FIG.
[0018]
In FIG. 1, reference numeral 1 denotes a reactor pressure vessel, and this reactor pressure vessel 1 is erected through a pedestal in a reactor well installed in a reactor building. A cylindrical core shroud 2 is installed in the reactor pressure vessel 1, and a number of in-core monitor guide tubes 3 are erected inside the core shroud 2. The in-core monitor guide tube 3 is welded to the in-core monitor housing 4 attached to the end plate of the reactor pressure vessel 1 as shown in an enlarged view in FIG.
[0019]
An in-core monitor housing 4 connected below the in-core monitor guide tube 3 standing in the reactor pressure vessel 1 is similarly a control rod drive mechanism housing 5 (hereinafter referred to as a CRD housing) attached to the end plate of the reactor pressure vessel 1. 5)).
[0020]
A shroud support cylinder 6 is provided at the lower end of the core shroud 2, and a temporary shield 7 is disposed at a level near the joint between the shroud support cylinder 6 and the reactor pressure vessel 1.
[0021]
The surface processing apparatus 8 according to the present embodiment is installed in the in-core monitor guide tube 3 in the CRD housing 5 using the opening 7a of the temporary shield 7 as shown in an enlarged manner in FIG. That is, as shown in FIG. 2, the surface processing apparatus 8 is installed so that a shot can be projected in the vicinity of the welded portion 51 between the in-core monitor guide tube 3 and the in-core monitor housing 4.
[0022]
The surface processing device 8 includes a bottomed container-like device body 26, a lid 27 for closing the upper end opening of the device body 26, a peening head mechanism 9 for sucking and collecting the projected shot, and a lifting mechanism 10 for moving the peening head mechanism 9 up and down. , A turning mechanism 11 for turning the peening head mechanism 9 around the entire circumference of the in-core monitor guide tube 3, a positioning mechanism 12 for positioning the peening head mechanism 9 on the welded portion 51 of the construction site, and a handle 46 attached to the apparatus main body 26 for in-core monitor guidance A clamp mechanism 13 fixed to the tube 3 and a shot injection recovery device 14 for injecting and recovering shots with high-pressure air, a peening head mechanism 9, an elevating mechanism 10, and a control panel 39 capable of controlling the operation of the turning mechanism 11 are configured.
[0023]
The peening head mechanism 9 has a projection nozzle 15 for projecting a shot from a nozzle hole 52 to a welded portion 51, a lifting shaft 16 for fixing the projection nozzle 15, and a scale 17 for displaying a vertical position of the projection nozzle 15. Yes. The elevating shaft 16 is surrounded by a shaft housing 22. In order to prevent the shot from leaking to the outside, the apparatus main body 26 and the lid 27 are provided with a rubber seal 30 for sealing.
[0024]
Further, as shown in FIG. 3, the lid 27 has a half-divided structure that is divided in half from the center. The lid 27 has four holes and a wire mesh 49 that closes the holes. It has a hinge 45 and a snap lock 29. A leg 48 is attached to the apparatus body 26, and a support 43 and a shaft housing 22 are attached to the lid 27. As with the lid 27, the apparatus body 26 can be divided into two parts from the center.
[0025]
The legs 48 are for making the surface processing apparatus 8 self-supporting. Wire mesh 49 is attached by welding to four holes provided in the lid 27 shown in FIG. This hole is an air intake for shot collection. The support 43 is attached to the lid 27 and supports the elevating mechanism 10 via the shaft housing 22.
[0026]
The elevating mechanism 10 includes an elevating motor 19, a ball screw 20 connected to the elevating motor 19 via a shaft, and a nut 21 fixed to the elevating shaft 16. When the elevating motor 19 rotates, the ball screw 20 rotates accordingly. However, since the ball screw 20 is fixed by the shaft housing 22 of the elevating shaft 16, it does not move up and down.
[0027]
Accordingly, the ball screw 20 is rotated by the driving of the lifting motor 19, and the nut 21 fixed to the lifting shaft 16 is moved up and down along with this rotation, whereby the projection nozzle 15 is moved up and down. Further, since the scale 17 moves up and down as the projection nozzle 15 moves up and down, the projection level can be confirmed by the indicator rod 18 fixed to the shaft housing 22.
[0028]
The turning mechanism 11 includes a turning motor 23 attached to the outside of the apparatus main body 26, a small-diameter turning gear 24 attached to the rotation shaft of the turning motor 23, and a large-diameter turning gear 25 that meshes with the small-diameter turning gear 24. It is configured. The projection nozzle 15 passes through the large-diameter swivel gear 25 and can move up and down.
[0029]
A hole is provided in the large-diameter turning gear 25, and a wire mesh 50 is attached to the hole, and this hole serves as an air intake port during shot suction. As the turning motor 23 rotates, the small-diameter turning gear 24 turns, and this power is transmitted to the large-diameter turning gear 25 so that the projection nozzle 15 rotates and moves around the in-core monitor guide tube 3, so Can be shot peened.
[0030]
A positioning mechanism 12 for accurately positioning the welded portion 51 of the peening head mechanism 9 is fixed to an apparatus main body 26 that surrounds and contacts a large-diameter turning gear 25 that is in contact with the projection nozzle 15. By bringing the upper lower surface of the positioning mechanism 12 into contact with the upper surface of the CRD housing 5, the projection nozzle 15 can be positioned on the welded portion 51.
[0031]
The clamp mechanism 13 for fixing the apparatus main body 26 to the in-core monitor guide tube 3 includes a handle 46 and a half pipe 47 connected to the apparatus main body 26. The clamp mechanism 13 can open the half pipe 47 by loosening the wing nut 28, and can clamp the in-core monitor guide tube 3 at an arbitrary position to fix the device.
[0032]
The apparatus main body 26, the lid 27, and the large-diameter swivel gear 25 are divided into two as viewed from above, and the apparatus main body 26 and the large-diameter swivel gear 25 are integrated by bolt fastening. The lid 27 is connected by a hinge 45 and can be integrated by a snap lock 29. The main body 26, the lid 27, and the large-diameter turning gear 25 can be easily attached to and detached from the in-core monitor guide tube 3 by loosening bolts (not shown) and releasing the snap lock 29.
[0033]
Rubber seals 30 are bonded to the contact portion with the in-core monitor guide tube 3 on the bottom surface of the apparatus body 26, the upper surface of the large-diameter turning gear 25, and the lower surface of the lid 27, respectively. Structure that can seal the inside of the device body 26 so that the shot does not leak out of the device body 26 in the unlikely event that all shots are not collected from the suction pipe 31 attached to the lower side surface of the device body 26 by this rubber seal 30 It has become.
[0034]
As shown in FIG. 1, the shot injection recovery device 14 includes an injection unit 32, a dust collection unit 33, a projection hose 34, a recovery hose 35, a duct hose 36, a compressor 37, and an air pipe 38. One of the projection hoses 34 is connected to the projection nozzle 15 of the peening head mechanism 9, and the other is connected to the ejection unit 32. The injection unit 32 and the compressor 37 are connected by an air pipe 38. The injection unit 32 and the dust collection unit 33 are connected by a duct hose 36. One of the recovery hoses 35 is connected to the suction pipe 31 of the apparatus body 26, and the other is connected to the injection unit 32.
[0035]
The dust collection unit 33 is driven in advance and is in a state of suction collection before shot projection, and by supplying air from the compressor 37, shots (not shown) contained in the tank of the injection unit 32 are projected to the projection hose 34. Through the projection nozzle 15 of the peening head mechanism 9. Thereby, the shot peening construction can be performed in the vicinity of the welded portion 51.
[0036]
In addition, the shots simultaneously projected can be sucked and collected to be repeatedly applied. The control panel 39 can control the operation of each mechanism of the surface processing apparatus 8 including the shot injection recovery apparatus 14.
[0037]
Next, an example of a method of handling the surface processing apparatus 8 for the in-reactor installation equipment having the above-described configuration will be described.
1 and 2, the injection unit 32 of the shot injection recovery device 14 is installed on the temporary lower template 40, the dust collection unit 33 is installed on the reactor pressure vessel bulkhead 41, and the compressor 37 is installed on the operation floor 42. Install in. The injection unit 32, the dust collection unit 33, and the duct hose 36 are connected. The injection unit 32 and the compressor 37 are connected by an air pipe 38. A projection hose 34 and a recovery hose 35 are connected to the injection unit 32.
[0038]
Next, the apparatus main body 26, the lid 27, the large-diameter turning gear 25 and the clamp mechanism 13 are divided into two on the temporary shield 7, and positioned on the CRD housing 5 by the positioning mechanism 12 and attached to the in-core monitor guide tube 3. The apparatus main body 26 is integrated. In this case, the projection nozzle 15 is installed at a predetermined height.
[0039]
The projection hose 34 and the recovery hose 35 are connected to the projection nozzle 15 and the suction pipe 31 of the peening head mechanism 9. The dust collection unit 33 of the shot injection collection device 14 is driven, and suction collection is started by the collection line. The compressor 37 is driven. When the operation button on the control panel 39 is pressed, the injection unit 32 is first driven, and a shot is projected from the projection nozzle 15 of the peening head mechanism 9 via the projection hose 34.
[0040]
Thereafter, the peening head mechanism 9 is turned by the turning mechanism 11 after a predetermined time, and shot peening is performed. When the turning mechanism 11 is stopped, the driving of the injection unit 32 is also stopped. When the turning of the peening head mechanism 9 by the turning mechanism 11 goes around the in-core monitor guide tube 3, the elevating mechanism 10 is continuously driven to perform shot peening.
[0041]
The above-mentioned turning and raising / lowering operations are repeated and stopped at a predetermined stroke. After the shot peening has been completed for the welded portion 51 at the predetermined construction site, the dust collection unit 33 is stopped. Thereafter, shot peening is performed in the vicinity of the welded portion 51 between all the in-core monitor guide tubes 3 and the in-core monitor housing 4 installed at the bottom of the reactor in the same procedure. In the present embodiment, the example in which shot peening is performed on the welded portion 51 has been described. However, the present invention is not limited to the welded portion 51 and may be applied to equipment installed in a nuclear reactor.
[0042]
【The invention's effect】
According to the present invention, it is possible to accurately position a peening head without an operator taking an unreasonable posture in a shot peening operation of a narrow portion constituted by an in-core monitor guide tube and an in-core monitor housing standing on the bottom of the reactor. The construction time can be shortened and the exposure dose of the worker can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a partial side view for explaining a first embodiment of a surface processing apparatus for in-reactor installation equipment according to the present invention;
2 is an enlarged longitudinal sectional view of the surface processing apparatus of the in-reactor installation equipment in FIG.
FIG. 3 is an enlarged top view showing the surface processing apparatus in FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Core shroud, 3 ... In-core monitor guide tube, 4 ... In-core monitor housing, 5 ... CRD housing, 6 ... Shroud support cylinder, 7 ... Temporary shield, 7a ... Opening, 8 ... Surface processing Device: 9 ... Peening head mechanism, 10 ... Lifting mechanism, 11 ... Turning mechanism, 12 ... Positioning mechanism, 13 ... Clamp mechanism, 14 ... Shot injection recovery device, 15 ... Projection nozzle, 16 ... Lifting shaft, 17 ... Scale, 18 ... indicator bar, 19 ... lifting motor, 20 ... ball screw, 21 ... nut, 22 ... shaft housing, 23 ... slewing motor, 24 ... small-diameter turning gear, 25 ... large-diameter turning gear, 26 ... device body, 27 ... lid, 28 ... Wing nut, 29 ... Pinch lock, 30 ... Rubber seal, 31 ... Suction tube, 32 ... Injection unit, 33 ... Dust collection unit, 34 ... Projection hose, 35 ... Collection hose, 36 ... Duct hose, 37 ... Compressor, 38 ... Air distribution Pipe, 39 ... Control panel, 40 ... Temporary lower template, 41 ... Reactor pressure vessel bulkhead, 42 ... Operation floor, 43 ... Support, 44 ... Notch, 45 ... Hinge, 46 ... Handle, 47 ... Half pipe, 48 ... legs, 49, 50 ... wire mesh, 51 ... welds, 52 ... nozzle holes, 53 ... support legs.

Claims (1)

A surface processing device for in- reactor installation equipment that performs shot peening in the vicinity of a welded portion between an in-core monitor guide tube and an in-core monitor housing that stands on the bottom of the reactor . The surface processing device is an in-core monitor guide. An apparatus main body supported by a clamp mechanism fixed to the tube via a handle, a positioning mechanism fixed to the apparatus main body and positioned by contacting the upper surface of the CRD housing, and an elevating mechanism and a turning mechanism in the apparatus main body A surface processing apparatus for in-reactor installation equipment, comprising: a peening head mechanism that is attached so as to be able to be moved up and down and swiveled to eject a shot; and a shot collection device that collects the shot .

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