JP2013000832A - Water jet peening method, and device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance corrosion resistance by forming an oxide film on a surface of an object to be worked by noble metal ions contained in a spray solution, when an entire surface of the object to be worked is subjected to WJP (water jet peening).SOLUTION: Platinum group ions (at least one kind selected from Pt, Pd, Ru, Ir, Rh and Os) are dissolved in spray water, and the spray water is sprayed onto to the surface of the object to be worked, and the film containing platinum groups is formed. Alternately, the noble metal ions are dissolved in water where the object to be worked is disposed, and then WJP can be performed using pure water.

Description

  The present invention relates to a water jet peening (hereinafter referred to as WJP (Water Jet Peening)) method and an apparatus used therefor, and in particular, WJP construction is not performed only on a limited part such as a welded portion of a construction object, The present invention relates to a WJP method suitable for WJP construction over the entire surface of a construction object or over a wide range.

  When residual stress exists near the surface of the welded part and heat-affected zone of the components of the nuclear reactor, water jet peening (hereinafter referred to as WJP) is applied to the welded zone and the heat-affected zone. Thus, the tensile residual stress existing in the vicinity of the surface of the component member is improved to the compressive residual stress. WJP is performed by injecting a high-pressure water flow from a nozzle in water in a state where a component for improving residual stress is immersed in water. Shock waves are generated by the collapse of the bubbles contained in the jetted water stream. When this shock wave collides with the surface of the constituent member in water, the tensile residual stress near the surface of the constituent member is improved to the compressive residual stress. For this reason, generation | occurrence | production of the stress corrosion crack (SCC) in a structural member is suppressed. The stress improvement method by WJP is described in Patent Documents 1 and 2, for example.

  Patent Document 3 describes that a compound containing a noble metal is attached to the surface of a structural member of a nuclear reactor by WJP.

  Furthermore, the improvement of corrosion resistance by surface modification is only an example that the corrosion rate indicated by the current density in polarization measurement is reduced by WJP construction in a steel material such as carbon steel, but is described in Non-Patent Document 1. ing.

During the WJP construction, a shock wave is generated when the bubble collapses, so that a stress improvement effect on the construction object can be expected. In addition, when bubbles collapse in WJP, decomposition products of water molecules (H ₂ O) such as OH radicals and O atoms may be released from the inside of the bubbles, which can improve the corrosion resistance of the construction object surface. There is sex. In such a case, the construction range of WJP is not limited to the welded portion or the heat affected zone, but covers the entire surface of the construction object or a wide range of the surface. In the case of full-scale construction, it is important to complete the full-scale construction in as short time as possible while avoiding construction omissions and multiple constructions. It is necessary to grasp.

  Among such techniques, there are many unclear points regarding the improvement of the corrosion resistance of the surface of the construction object, and only the effects shown in Non-Patent Document 1 have been reported.

Japanese Patent No. 2841963 Japanese Patent No. 3530005 Japanese Patent No. 4283166

Soyama So, Material test and surface modification by cavitation jet, Material, vol.47, NO.4, pp.381-387, Apr.1998

  An object of the present invention is to provide a water jet peening method and an apparatus for improving corrosion resistance when the entire surface of a construction object or a wide area of the surface is constructed by WJP.

  In the water jet peening method of the present invention, water supplied from a pump is injected from the nozzle into the water in which the nozzle is present, and the nozzle that is injecting the water is subjected to water jet peening execution in the water. Scanning along the object, the oxidizing ions generated by crushing the bubbles contained in the water jetted from the nozzle into the water are applied to the water jet peening object, and applied to the surface of the object. An oxide film is formed.

  According to the present invention, corrosion resistance can be imparted to the entire surface of the construction object by WJP.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the WJP apparatus used for the WJP method of Example 1 which is one Example of this invention. The figure which compared the corrosion amount measured in artificial seawater, after giving the WJP process to the carbon steel surface using the WJP apparatus of FIG. The figure which compared the corrosion amount measured in the artificial seawater after performing a WJP process on the stainless steel (SUS316L) surface using the WJP apparatus of FIG. The figure which compared the corrosion amount measured in artificial seawater, after performing the WJP process to the alloy 182 surface which is a nickel base alloy using the WJP apparatus of FIG. The figure which showed the time-dependent change of the corrosion amount at the time of processing 316L stainless steel surface with the WJP apparatus of FIG. 1, and being immersed in the artificial seawater of 3.5% for 1000 hours. The surface of the nickel base alloy 182 is processed by the WJP apparatus of FIG. 1 and the amount of corrosion when immersed in high-temperature pure water having a dissolved oxygen concentration (DO) of 200 ppb and a temperature of 288 degrees, which is a reactor water environment, for up to 1000 hours. The figure which showed the time change. It is a figure which shows a shock wave. The block diagram of the WJP apparatus used for the WJP method of Example 2 which is another Example of this invention. The perspective view of the turntable vicinity of the WJP apparatus shown in FIG. The enlarged view of the moving apparatus provided with the nozzle of the WJP apparatus shown in FIG. The figure which shows typically the form of the bubble in the water flow injected from the nozzle.

A feature of the present invention is included in a jet jetted into water from a nozzle from which a decomposition product of water molecules (H ₂ O) such as OH radicals and O atoms is released from the inside of the bubble when the bubble collapses in WJP. Due to the shock wave generated by the collapse of the bubbles, the positive ions in the aqueous solution contained in the jet promote the oxide film formation reaction that occurs on the metal surface, which is the construction target surface, due to the action of radicals and water decomposition products. It is to make it a corrosion-resistant film.

  Moreover, about the apparatus regarding WJP construction, it adds to the component that it controls with the apparatus which provides the electromagnetic field which installed the oxide film of the positive ion in a solution in the injection nozzle. As a result, the efficiency of imparting corrosion resistance by forming an oxide film by WJP construction can be improved, and a WJP apparatus suitable for surface treatment that suppresses corrosion can be configured.

  Hereinafter, the present invention will be described in detail.

  In WJP, high-pressure jet water is jetted toward a construction object existing in water. When a jet is jetted into water, a phenomenon called cavitation occurs where bubbles are generated and collapsed. When the bubble contracts immediately before the bubble collapses, the inside of the bubble becomes a high temperature and a high pressure. For this reason, a shock wave is generated at the moment when the bubbles collapse, and at the same time, decomposition products of water molecules such as OH radicals and O atoms generated in a high-temperature and high-pressure environment are released toward water and the surface of the work object. Residual stress can be improved not only by the excitation force when the jet directly hits the work object, but also by the shock wave force, and at the same time the effect of improving the corrosion resistance of the surface of the work object by the oxidizing power of the water decomposition products Can also be expected.

FIG. 11 schematically shows a state from when bubbles are generated in the jet that has been ejected until they are crushed. High pressure water 38 is supplied from a pump (not shown) to the nozzle 6 disposed in the water 3.
When the high-pressure water 38 is jetted into the water from the jet port 37 of the nozzle 6, a cavitation cloud 39 is generated in which a large number of minute bubbles are generated in the water to form a lump. When one or several bubbles collapse in the generated cavitation clouds 39, a shock wave and water decomposition products are released. When a bubble collapses and a shock wave is generated, a large number of bubbles present around the bubble are swept away by the shock wave. For this reason, the vortex cavitation 40 in which the group of bubbles to be washed away is continuous is formed. Furthermore, a spot 41 that looks as if the bubble has disappeared because the bubble has been swept away is observed. In FIG. 11, reference numeral 42 denotes a bubble whose diameter is increased by combining small bubbles. In addition, in FIG. 11, the construction target object does not exist in the figure and the condition which ejected the free jet in water is shown. When the jet collides with the construction object, the cavitation cloud 39 and the like spread in a direction away from the center of the jet, so that the distribution of the bubble collapse occurrence position may spread in a direction parallel to the construction object surface.

  The stress improvement effect and corrosion resistance improvement effect on the construction object are not caused by the presence of bubbles in the jet, but are caused by the collapse of the bubbles.The closer the distance between the bubble collapse position and the surface of the construction object, the greater the effect. large.

  The present inventors do not depend on the number of bubbles in the jet, but the number of bubble collapses per unit time (bubble collapse frequency), that is, the number of shock waves generated per unit time (shock waves). It was found that it can be confirmed by the occurrence frequency of In addition, since the effective range in which the WJP construction effect can be obtained on the surface of the construction object and the bubble collapse occurrence range (= shock wave generation range) substantially coincide with each other, the inventors of the present invention have a position parallel to the construction object surface (jet flow Oxidation reaction on the surface of the work object progresses due to the generation of shock waves at every distance from the center), and OH radicals and water decomposition excited molecules inherent in the jet group method react with the surface metal of the work object to generate oxide or It was found to be a hydroxide. At this time, if noble metal ions such as Pd and Pt are present in the jet, these noble metal ions are added to the oxidation reaction, and the surface metal to be constructed as a composite compound in the oxide or hydroxide formed. It was found to be responsible for the film reaction as well. The present invention has been made based on these findings.

  The concept of the present invention based on these findings will be described using one specific example shown in FIG. The nozzle 6 and the support member 17 are attached to the nozzle scanning device 10, and two ion sensors (charge detection devices) 14 </ b> A and 14 </ b> B are installed at intervals in the direction parallel to the surface of the construction object 2. The nozzle 6 and the ion sensors 14A and 14B are disposed in the water, and the WJP construction target object 2 is also disposed in the water. The nozzle 6 faces the surface of the construction object 2 on which WJP is constructed. The ion sensors 14 </ b> A and 14 </ b> B are arranged near the surface of the construction object 2 and at a position slightly away from the jet center ejected from the nozzle 6. The ion sensors 14A and 14B are attached to the support members 16A and 16B, respectively, and are configured to move following the scanning of the nozzle 6. As the ion detector, a pH sensor, a potential sensor, or an absorbance sensor may be used in addition to the ion sensor.

  When bubbles contained in the high-pressure water stream 34 ejected from the nozzle 6 are crushed, an ion-containing aqueous solution is generated. This ion-containing aqueous solution detects ions by the ion sensors 14A and 14B and outputs an ion detection signal.

The ion concentration in the water of the ion-containing aqueous solution is V (ml / cm ³ ), and a sensor (for example, an ion sensor) that is close to the position of ion generation (the position where bubbles are crushed, that is, the position where the ion-containing aqueous solution is generated). 14B), the coordinate value in the Y-axis direction is y1 (m), the coordinate value in the Y-axis direction of the sensor (for example, the AE sensor 14A) located far from the position of the sound source is y2 (m), and the coordinate value exists in the near position. The radical action time on the ion sensor is t (s), and the time difference of the ion concentration detection time in the ion sensor existing in a position close to the ion sensor detection time in the far position is T1 (s). . In the one-dimensional approximation model of the reactive ion arrival path by radicals in the Y-axis direction, the arrival time of ions from the ion generation position to each ion concentration detection device, for example, the ion sensors 16B and 16A, is expressed by Equations (1) and (2). It is expressed by a formula.
V * t = (y1-y0) (1)
V × (t + T1) = (y0−y2) (2)

t (s) cannot actually be measured, and the time difference T1 (s) can be measured.
When the diffusion diffusion speed V (m / s) of ions in water is known (for example, underwater sound speed 1500 (m / s)), the coordinate value of the ion generation position in the Y-axis direction (Y of the ion generation position) (Axial position) y0 (m) is a reactive ion generation position, and can be calculated by the equation (3).
y0 = (y1 + y2) / 2−V × T1 / 2 (3)

  In WJP, high-pressure jet water is jetted toward a construction object existing in water. When jets are injected into the water, cavitation occurs where bubbles are generated and collapsed. When the bubble contracts immediately before the bubble collapses, the inside of the bubble becomes high temperature and high pressure, and a shock wave is generated at the moment when the bubble collapses, and at the same time, decomposition and generation of water molecules such as OH radicals and O atoms generated in a high temperature and high pressure environment. Objects are released toward the surface of the work and underwater. Residual stress can be improved not only by the excitation force when the jet directly hits the work object, but also by the shock wave force, and at the same time the effect of improving the corrosion resistance of the surface of the work object by the oxidizing power of the water decomposition products Can also be expected. Under the present circumstances, the property of the film | membrane formed on the construction object metal surface changes by melt | dissolving the noble metal nitrate etc. previously in a jet, and making it the aqueous solution containing a noble metal ion. That is, it was found that the cation valence of the metal of the construction target metal increases because it is more oxidized, and the noble metal ion also becomes the more oxidized valence and becomes an oxide or hydroxide. This is presumably because the oxidizing action of OH radicals and water decomposition products acted strongly on the metal surface.

  Examples of the present invention will be described below.

  A water jet peening method according to a first embodiment which is a preferred embodiment of the present invention will be described with reference to FIGS.

  Before describing the water jet peening method of this embodiment, a water jet peening apparatus (hereinafter referred to as a WJP apparatus) 1 used in this embodiment will be described with reference to FIG. The WJP device 1 includes a nozzle 6, a high-pressure pump 5, a nozzle scanning device 10, an AE sensor (shock wave detection device) 14A and 14B, a signal processing device 20, a nozzle scanning control device 31, and a pump control device 30.

  The nozzle scanning device 10 includes an X-axis scanning mechanism 11, a Y-axis scanning mechanism 12, and a Z-axis direction scanning mechanism 13, holds the injection nozzle 6, and scans the nozzle 6 in the water 3 in the water tank 4. A water supply hose 7 is attached near the bottom of the water tank 4 and connected to the high-pressure pump 5. A high pressure hose 9 is connected to the high pressure pump 5 and the nozzle 6. The water tank 4 is provided with a chemical solution injector 50 so that an additive other than water can be added to the supply water and stirred.

  The signal processing device 20 includes an A / D converter 21, an ion extraction unit 22, an ion concentration calculation unit 23, a reaction ion calculation unit 24, a film formation calculation unit 25, a corrosion rate calculation unit 26, a corrosion resistance index calculation unit 27, and a recording / recording unit. A display information creation unit 28 is included. The ion extraction unit 22 is connected to the A / D converter 21. The A / D converter 21 is connected to an ion concentration calculation unit 23 and a series of calculation units including a reaction ion calculation unit 24, a film formation calculation unit 25, a corrosion rate calculation unit 26, and a corrosion resistance index calculation unit 27. An A / D converter 21, an ion extraction unit 22, a corrosion resistance index calculation unit 27, and a display device 29 are connected to the recording / display information creation unit 28.

  Ion sensors 14 </ b> A and 14 </ b> B, which are ion detection devices, are attached to the nozzle scanning device 10 and installed in the water 3 in the water tank 4. The ion sensors 14 </ b> A and 14 </ b> B are attached in a straight line shape near the surface of the construction object 2 and parallel to the Y axis and passing through the jet center. A densitometer 15A and an amplifier 15B are attached to the nozzle scanning device 10. The ion sensor 14A is connected to the amplifier 15B, and the ion sensor 14B is connected to the densitometer 15A. An amplifier 15B and an ion sensor 15B are connected to the A / D converter 21.

  A nozzle scanning control device 31 is connected to the nozzle scanning device 10 and controls the X-axis scanning mechanism 11, the Y-axis scanning mechanism 12, and the Z-axis direction scanning mechanism 13. A pump control device 30 is connected to the high pressure pump 5. A pressure gauge 33 and a flow meter 32 attached to the high pressure hose 9 are connected to the pump control device 30. A pump control device 30 and a nozzle scanning control device 31 are connected to the signal processing device 20.

The water jet peening method of the present embodiment performed using the WJP apparatus 1 will be described.
In the water jet peening method of the present embodiment, the following operations or processes are performed.

  Water 3 is filled in the water tank 4, and the WJP construction object 2 is installed in the water 3 in the water tank 4. This construction object 2 is a structural member installed in a plant, for example, a nuclear plant to be constructed. Alternatively, the construction object 2 is a component of a nuclear power plant that has undergone operation, and the equipment of FIG. 1 is configured in a reactor pressure vessel or pool filled with water located in the management area of the plant. WJP may be applied. In FIG. 1, the construction object 2 is schematically shown in a simplified shape.

  When carrying out WJP construction, first, search for appropriate injection conditions by fixed hitting with the nozzle 6 fixed with respect to the X-axis and Y-axis. After the injection conditions are determined, the nozzle 6 is moved in the X-axis and Y-axis directions. A rectangular scan.

  The nozzle 6 is moved to the scanning start position in the X-axis / Y-axis directions, and the standoff is set to be the upper limit value of the search condition. When the high-pressure pump 5 is activated, the water 3 in the water tank 4 is guided to the high-pressure pump 5 through the water supply hose 7. The pump control device 30 controls the pressure of water discharged from the high-pressure pump 5 based on the measurement value of the pressure gauge 33. Also, if the pressure of the feed water is determined, it should take a value in an appropriate range according to the high pressure hose 9 and the nozzle 6, but if the measured value of the flow meter 32 deviates from the appropriate range, WJP Since there should be a defect somewhere in the device 1, the injection is stopped and the device is checked.

  As shown in FIG. 7, the water 3 discharged from the high-pressure pump 5 is supplied to the nozzle 6 through the high-pressure hose 9 with the initial pressure and flow rate, and becomes a high-pressure water stream 34 from the nozzle 6. Injected into the water. A shock wave 35 is generated when the air bubbles 36 in the jetted water stream 34 are crushed in water.

  Here, when the bubbles 36 in the water stream 34 break down in the water, when noble metal ions are present in the water due to the action of the shock wave 35, the surface reaches the construction target metal surface in an increased oxidizing power.

  When the precious metal ion is Pd, the concentration in the jet water is set to 100 ppm, and after spraying to carbon steel, SUS316L stainless steel, 182 nickel base alloy, it is immersed in artificial seawater for up to 100 hours to remove the corrosion products, and then the weight is reduced. The measurement results are shown in FIGS.

  FIG. 2 is an example in which the amount of corrosion measured in artificial seawater is compared after the WJP treatment is performed on the carbon steel surface using the WJP apparatus shown in FIG. A is untreated without WJP, B is WJP treatment with pure water, and C is the amount of corrosion when 100 ppm of Pd is contained in the WJP jet water. D shows the amount of corrosion when 10 ppm of Pd is contained in the WJP jet water. E shows the amount of corrosion when 10 ppm of Pt is contained in the WJP jet water. F shows the amount of corrosion when 10 ppm of Rh is contained in the WJP jet water.

  FIG. 3 is an example in which the amount of corrosion measured in artificial seawater is compared after the WJP treatment is applied to the surface of stainless steel (SUS316L) using the WJP apparatus shown in FIG. A is untreated without WJP, B is WJP treatment with pure water, and C is the amount of corrosion when 100 ppm of Pd is contained in the WJP jet water. D shows the amount of corrosion when 10 ppm of Pd is contained in the WJP jet water. E shows the amount of corrosion when 10 ppm of Pt is contained in the WJP jet water. F shows the amount of corrosion when 10 ppm of Rh is contained in the WJP jet water.

  FIG. 4 is an example in which the corrosion amount measured in artificial seawater is compared after the WJP treatment is performed on the surface of the alloy 182 which is a nickel-based alloy using the WJP apparatus shown in FIG. A is untreated without WJP, B is WJP treatment with pure water, and C is the amount of corrosion when 100 ppm of Pd is contained in the WJP jet water. D shows the amount of corrosion when 10 ppm of Pd is contained in the WJP jet water. E shows the amount of corrosion when 10 ppm of Pt is contained in the WJP jet water. F shows the amount of corrosion when 10 ppm of Rh is contained in the WJP jet water.

  FIG. 5 shows changes over time in the amount of corrosion when a 316L stainless steel surface is treated by the WJP apparatus shown in FIG. 1 and immersed in 3.5% artificial seawater for up to 1000 hours. A is untreated without WJP, B is WJP treatment with pure water, C is the amount of corrosion when 10 ppm of Pd is contained in the WJP jet water, and D is the amount of corrosion when 10 ppm of Pt is contained in the WJP jet water.

  FIG. 6 shows a case where the surface of the nickel-based alloy 182 is processed by the WJP apparatus shown in FIG. 1 and immersed in high-temperature pure water having a dissolved oxygen concentration (DO) of 200 ppb and a temperature of 288 degrees, which is a reactor water environment, for up to 1000 hours. This shows the change over time in the amount of corrosion. A is untreated without WJP, B is WJP treatment with pure water, and C is the amount of corrosion when 10 ppm of Pd is contained in the WJP jet water.

  In both cases where there was no WJP construction (A), the amount of corrosion increased after WJP treatment or after WJP treatment with noble metal ion injection, and more than twice as much as WJP with noble metal injection.

  This indicates that the formation of an oxide film by WJP proceeds on the WJP construction surface metal by WJP and noble metal ion implantation WJP, and the film has corrosion resistance. Pd ions were contained in the oxide film as a cation fraction of 10% or more, and the ionic valence of Pd was increased from 2 to 4 as usual. This increase in the valence of Pd can be confirmed by XPS (X-ray photoelectron spectroscopy). This is related to the enhancement of the oxidation effect due to the sonochemistry effect, and the oxidation film formed on the surface of the construction metal becomes a large barrier to the subsequent corrosive action of the environment because the oxidation effect is remarkably generated compared with the case where there is no WJP effect. It is shown that. Even when Rh is used, good corrosion resistance can be obtained.

  In addition, the noble metal ion can be melt | dissolved in the water by which the construction target object is arrange | positioned, and the WJP construction by a pure water can also be performed. Thereby, the corrosion inhibitory effect equivalent to the case where a noble metal ion is dissolved in jet water is acquired.

  A water jet peening method according to embodiment 2, which is another embodiment of the present invention, will be described with reference to FIG. The WJP method of the present embodiment is performed on, for example, an in-reactor structure installed in a reactor pressure vessel of a boiling water nuclear plant. This in-furnace structure is, for example, a core shroud.

  The structure near the nuclear reactor of the boiling water nuclear power plant will be described with reference to FIG. A nuclear reactor 75 of a boiling water nuclear power plant includes a reactor pressure vessel (hereinafter referred to as RPV) 76, a core shroud 77, a core support plate 79, an upper lattice plate 80, and a jet pump 81. The core shroud 77, the core support plate 79, the upper lattice plate 80, and the jet pump 81 are installed in the RPV 76. In the core shroud 77 surrounding the core, a core support plate 79 located at the lower end of the core is installed, and an upper lattice plate 80 located at the upper end of the core is installed. A plurality of jet pumps 81 are disposed in an annular downcomer 82 formed between the RPV 76 and the core shroud 77.

  The WJP apparatus 1B used in the water jet peening method of the present embodiment has a configuration in which the nozzle scanning apparatus 10 in the WJP apparatus 1 used in the first embodiment is replaced with a nozzle scanning apparatus 10A. Other configurations of the WJP apparatus 1B are the same as those of the WJP apparatus 1.

  The nozzle scanning device 10A will be described. As shown in FIGS. 8 to 10, the nozzle scanning device 10 </ b> A includes moving devices 58 </ b> A and 58 </ b> B, a post member 62, an elevating body 63, and a turntable 65. The turntable 65 is rotatably installed on an annular guide rail 66 installed on the upper surface of the upper flange 78 of the core shroud 77. The turntable 65 is provided with a plurality of wheels (not shown) that come into contact with the upper surface of the guide rail 66. A motor (not shown) that rotates at least one wheel (not shown) is provided on the turntable 65. Moving devices 58A and 58B are installed on the turntable 65.

The moving devices 58A and 58B having the same configuration will be described by taking the moving device 58A as an example.
As shown in FIG. 10, the moving device 58 </ b> A has a device main body 59, two arms 60, and a ball screw 72. Two arms 60 pass through the casing of the apparatus main body 59 and are slidably attached to the casing. Both ends of the two arms 60 are connected by connecting members 61A and 61B. A ball screw 72 passing through the casing of the apparatus main body 59 is rotatably attached to the connecting members 61A and 61B. Although not shown, a motor is installed in the casing of the apparatus main body 59, and a gear (not shown) attached to the rotation shaft of the motor meshes with a gear (not shown) that meshes with the ball screw 72. Yes. The gears are rotated by driving the motor, and the ball screw 72 is moved in the radial direction of the RPV 76. A post member 62 extending in the axial direction of the RPV 76 is attached to the connecting member 61B. The elevating body 63 is attached to the post member 62 so that it can move along the post member 62. A motor 64 that moves the elevating body 63 up and down is provided at the upper end of the post member 62.

  The nozzle 6, the AE sensors 14A and 14B, and the monitoring camera 67 are installed on the lifting body 63.

In this embodiment, WJP is applied to the outer surface of the upper end portion of the core shroud 77. In this embodiment, the core shroud 77 is a WJP construction target object. After the operation of the boiling water nuclear power plant is stopped, the upper lid of the RPV 76 is removed, and the steam dryer and the steam separator installed in the RPV 76 are removed and carried out of the RPV 76. These are carried out using an overhead crane (not shown) in the reactor building where the RPV 76 is installed.
When performing these removal and unloading operations, water 3 is filled in the reactor well 68 located immediately above the RPV 76.

  The guide rail 66 is transferred onto the upper flange 78 using the overhead crane and installed on the upper flange 78. The turntable 65 on which the moving devices 58 </ b> A and 58 </ b> B are installed is transported by the overhead crane and installed on the guide rail 66. The post member 62 to which the elevating body 63 is attached is installed in each of the moving devices 58A and 58B before the turntable 65 is conveyed. When the turntable 65 is installed on the guide rail 66, the post member 62 provided on each of the moving devices 58 </ b> A and 58 </ b> B is disposed in the downcomer 82.

  The high-pressure pump 5 is placed on the operation floor 69 in the reactor building, and the signal processing device 20, the nozzle scanning control device 31, and the pump control device 30 are provided. The operation floor 69 surrounds the reactor well 68. Two high-pressure hoses 9 connected to the high-pressure pump 5 are respectively attached to the moving devices 58A and 58B, and are separately connected to the nozzle 6 provided in the moving device 58A and the nozzle 6 provided in the moving device 58B. Yes.

  A control signal line 71 connected to the nozzle scanning control device 31 is provided with a motor 64 provided in each of the moving devices 58A and 58B, a motor provided in the casing of the device main body 59, and a turntable 65. Each is connected to a motor that rotates the wheels of the table 65. Each motor is provided with an encoder (not shown), and each encoder detects a moving distance of a member moved by the motor, that is, a position after the member moves.

  Also in this embodiment, each effect produced in the first embodiment can be obtained.

  The present invention can improve the residual stress of the construction object and improve the corrosion resistance.

1, 1A, 1B WJP device 4 Water tank 5 High pressure pump 6 Nozzle 9 High pressure hose 10 Nozzle scanning device 14A, 14B Ion sensor 20 Signal processing device 22 Shock wave signal extraction unit 23 Total shock wave generation frequency calculation unit 24 Reactive ion calculation unit 25 Generation Position calculation unit 26 Frequency distribution calculation unit 27 Effective width calculation unit 28 Recording / display information creation unit 29 Display device 30 Pump control device 31 Nozzle scanning control device 50 Chemical solution injection device 60 Arm 62 Post member 63 Lifting body 65 Turntable 76 Reactor Pressure vessel 77 core shroud

Claims (8)

  Water that is supplied from a pump is jetted from the nozzle into the water in which the nozzle is present, the nozzle that is jetting the water is scanned along the water jet peening object to be present in the water, and the nozzle From which the bubbles contained in the water jetted into the water are crushed and applied to the water jet peening work object to form an oxide film on the surface of the work object. Water jet peening method.   The water jet peening method according to claim 1, wherein the oxidizing ions are detected using an ion sensor.   2. The water jet peening method according to claim 1, wherein noble metal ions are previously dissolved in the jet water.   4. The water jet peening method according to claim 3, wherein the noble metal ion is at least one ion selected from Pt, Pd, Ru, Ir, Rh and Os.   5. The water jet peening method according to claim 3, wherein the concentration range of the noble metal ions is 5 ppm or more and 100 ppm or less.   2. The water jet peening method according to claim 1, wherein the water jet peening object is a reactor internal structure in a reactor vessel. In a water jet peening apparatus comprising a nozzle that is present in water and jets water, a pump that supplies water to the nozzle, and a scanning device that holds and scans the nozzle in water,
The scanning device includes a chemical injection device, and is a water jet peening device.   8. The water jet peening apparatus according to claim 7, wherein an electromagnetic generator is installed around the jet nozzle, and an electromagnetic field is applied to the jet water for control.