JP2005213538A - Surface treatment method of heat transfer tube of steam generator for nuclear reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment method of a heat transfer tube capable of reducing exposure dose by reducing Ni elution from the heat transfer tube as much as possible. <P>SOLUTION: The surface treatment method of the heat transfer tube made of Ni-Cr-Fe alloy of a steam generator for a nuclear reactor comprises: a step of blasting an inner surface of the heat transfer tube by using beads of very small grain size; and a step of depositing a film on the inner surface of the heat transfer tube by immersing the blasted heat transfer tube in high-temperature water or distributing high-temperature water over the inner surface of the heat transfer tube. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surface treatment method for a heat transfer tube used in a high-temperature and high-pressure water environment such as a heat transfer tube of a steam generator for a nuclear reactor, for example, a steam generator tube of a pressurized water reactor (PWR).

  The heat transfer tubes used in the reactor steam generator (SG) are composed of Ni-Cr-Fe alloys (for example, 600 alloys, 690 alloys, 800 alloys, etc.), and the chemical composition is Ni content. 30% or more, Cr content of 10% or more, and the balance is Fe. From such a wetted part inside the heat transfer tube, dissolution of Ni in the alloy may occur in high temperature water, and elution may occur in water. The eluted Ni moves together with the circulating high-temperature water, and around the vicinity of the fuel in the reactor core, transmutation occurs in that portion, and Ni is converted into radioactive material (Co etc.). Therefore, circulation of this radioactive substance increases the radiation dose in the primary high-temperature water, which may increase the radiation dose for workers during regular inspections. It was said.

  At present, as a technique for reducing exposure, attempts have been made to reduce exposure by putting Zn metal in high-temperature water (Non-Patent Documents 1 and 2). However, since it is necessary to add a new element and it is necessary to monitor and control the operating conditions, there is a drawback that the operation of the system becomes complicated. Therefore, it was considered necessary to reduce the exposure dose by reducing Ni elution from the heat transfer tube as much as possible.

C.A.Bergmann, R.E.Gold, J.Sejvar, J.D.Perock, M.Dove, R.S.Pathiania, Water Chemistry of Nuclear Reactor Systems 7, BNES (1996) p.287. R.S.Pathiana, B.Cheng, M.Dove, R.E.Gold, C.A.Bergmann, Fontevraud IV (1998) p.959.

In view of the above problems, the present inventors have advanced research to solve the problems of the prior art, and by reducing Ni elution from the heat transfer tube as much as possible, the surface of the heat transfer tube that can reduce the exposure dose In order to develop a treatment method, we studied diligently.
As a result, the present inventors have found that such a problem can be solved by a surface treatment method for a heat transfer tube that reduces Ni elution by forming a surface film in advance. The present invention has been completed from such a viewpoint.

That is, the first embodiment of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy. A reactor that includes a process of blasting using a blast furnace and a process of forming a film in the operation of circulating high-temperature water in the PWR primary system simulation environment before the start of operation, which is called actual machine HFT (Hot Function Test) processing Provided is a surface treatment method for a steam generator heat transfer tube. In addition, the inner surface of the heat transfer tube is subjected to a blasting process using beads having a small particle diameter, and the blasted heat transfer tube is included in high-temperature water (including water in which B, Li, and H ₂ are dissolved at a constant concentration). A surface treatment method for a steam generator heat transfer tube for a nuclear reactor including a step of forming a film on the inner surface of the heat transfer tube by immersing in the heat transfer tube or circulating high temperature water on the inner surface of the heat transfer tube It is. In this embodiment, by distorting in advance by blasting, by accelerating the formation of the surface film at the time of immersion in high temperature water or trial operation in high temperature water (HFT: Hot Function Test) before starting operation Ni elution from the heat transfer tube can be reduced.

A second embodiment of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy, and a film is formed by immersing the inner surface of the heat transfer tube in nitric hydrofluoric acid. A surface treatment method for a steam generator heat transfer tube for a nuclear reactor, which includes a nitric hydrofluoric acid treatment step to be removed and a passivation treatment step (nitric acid treatment step) in which a HNO ₃ (nitric acid) aqueous solution is contacted to form a film. . Here, in addition to the nitric hydrofluoric acid treatment step and the nitric acid treatment step, the heat transfer tube subjected to the nitric acid treatment is put into an actual machine HFT treatment that distributes the high temperature water of the PWR primary system simulation environment before the start of operation, or in high temperature water. A step of forming a film on the inner surface of the heat transfer tube by immersing or circulating high temperature water on the inner surface of the heat transfer tube may be included. In the present embodiment, Ni elution from the heat transfer tube can be reduced by forming a film in which Cr is concentrated on the surface.

  A third aspect of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy, which is immersed in nitric hydrofluoric acid on the inner surface of the heat transfer tube. A step of removing the film and a step of passivating the surface by bringing the citric acid aqueous solution into contact (citric acid treatment step) can be included. Here, in addition to the nitric hydrofluoric acid treatment step and the citric acid treatment step, the heat transfer tube that has been subjected to the citric acid treatment is an actual machine HFT treatment that distributes the high-temperature water of the PWR primary system simulation environment before the start of operation, or a high temperature The method may include a step of forming a film on the inner surface of the heat transfer tube by immersing in water or circulating high temperature water on the inner surface of the heat transfer tube. In the present embodiment, Ni elution from the heat transfer tube can be reduced by forming a film in which Cr is concentrated on the surface.

A fourth embodiment of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy, and beads having a small particle diameter are used on the inner surface of the heat transfer tube. And a passivation treatment step (nitric acid treatment step) for forming a film by bringing a HNO ₃ (nitric acid) aqueous solution into contact with the inner surface of the blasted heat transfer tube. . In this embodiment, strain is preliminarily applied by blast treatment, and Ni and Fe are selectively dissolved in the nitric acid treatment step, and a film in which Cr is concentrated on the surface is accelerated from the application of strain during blast treatment. By forming it, the amount of Ni elution from the heat transfer tube can be reduced.

  A fifth aspect of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy, and beads having a small particle diameter are used on the inner surface of the heat transfer tube. A blasting step, an inner surface of the blasted heat transfer tube is brought into contact with a citric acid aqueous solution to passivate the surface (citric acid treatment step), and the citric acid-treated heat transfer tube, The inner surface of the heat transfer tube by circulating the high temperature water in the actual machine HFT treatment that circulates the high temperature water of the PWR primary system simulation environment before the start of operation, or by immersing the high temperature water in the inner surface of the heat transfer tube And a step of forming a film on the surface.

A sixth aspect of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy, and beads having a small particle diameter are used on the inner surface of the heat transfer tube. A blasting step, a step of removing the coating by immersing in nitric hydrofluoric acid on the inner surface of the blasted heat transfer tube, and contacting the nitric hydrofluoric acid-treated heat transfer tube with an HNO ₃ (nitric acid) aqueous solution. Passivation treatment process (nitric acid treatment process) that forms a film, and in addition, heat transfer tubes that have been subjected to the blast treatment, nitric hydrofluoric acid treatment, and nitric acid treatment are treated with hot water from the PWR primary system simulation environment before the start of operation. An actual machine HFT treatment to be circulated, or a step of forming a film on the inner surface of the heat transfer tube by immersing in high temperature water or circulating high temperature water on the inner surface of the heat transfer tube. Treatment method for steam generator heat transfer tubes for nuclear reactors A.

  A seventh aspect of the present invention is a surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy, and beads having a small particle diameter are used on the inner surface of the heat transfer tube. Blasting, immersing the niobium hydrofluoric acid to remove the coating on the inner surface of the blasted heat transfer tube, and forming the coating by contacting the nitric hydrofluoric acid-treated heat transfer tube with an aqueous citric acid solution In addition to the passivating process (citric acid treatment process), in addition to the heat treatment tube subjected to the blast treatment, nitric hydrofluoric acid treatment and citric acid treatment, hot water of the PWR primary system simulated environment before the start of operation is used. And a step of forming a film on the inner surface of the heat transfer tube by immersing in an actual HFT treatment to be circulated, or immersing in high temperature water, or circulating high temperature water on the inner surface of the heat transfer tube. Surface treatment of reactor steam generator heat transfer tubes It is a method.

As described above, according to the surface treatment method of the present invention, Ni elution from the heat transfer tube can be reduced as much as possible by forming a surface film on the inner surface of the reactor steam generator heat transfer tube in advance. This can reduce the exposure dose in the nuclear facility.
Hereinafter, although the present invention will be described in detail according to the best mode for carrying out the present invention, the present invention is not limited to these embodiments.

The object of the surface treatment method of the present invention is a heat transfer tube of a steam generator for a reactor made of a Ni—Cr—Fe alloy. The chemical composition of the Ni-Cr-Fe alloy is usually 10 to 40% Cr, 30 to 80% Ni, and the balance is Fe, specifically, for example, 30% Cr of the 690 alloy, 60% The composition of Ni, the remaining Fe, or the composition of 15% Cr and 70% Ni of 600 alloy, the remaining Fe, or the composition of 20% Cr, 35% Ni of 800 alloy, the remaining Fe, and the like.
Ni is ⁵⁸ Co when activated and is the element with the greatest contribution of dose rate to radiation exposure. On the other hand, the Ni content is 50% because of its excellent resistance to intergranular stress corrosion cracking in high-temperature water. % Ni-Cr-Fe alloy. The Ni—Cr—Fe alloy targeted by the surface treatment method of the present invention is an alloy having excellent intergranular stress corrosion cracking resistance with a Ni content of 50% or more, preferably 55% or more.
Cr is an indispensable element for maintaining the corrosion resistance of the alloy. If it is 10% or less, the corrosion resistance required for the heat transfer tube application cannot be secured, and if it exceeds 40%, the hot workability generally deteriorates.

The heat transfer tube material (alloy) that is the subject of the method of the present invention may contain other elements as needed in addition to the above-described Ni and Cr to ensure the strength of the alloy. Specifically, for example, C can be contained in an amount of 0.015 to 0.025%, Mn up to 0.5%, Mo up to 0.2%, and Nb + Ta up to 0.1%. Further, among the impurity elements, the contents of Co, B, P and S are limited.
The heat transfer tube is manufactured by using the above alloy as a raw material, and manufacturing a raw tube by a normal tube forming method, for example, a hot extrusion method, and then cold drawing or cold rolling to finish the product dimensions. Can do. Next, heat treatment such as solution heat treatment or carbide precipitation treatment (grain boundary strengthening heat treatment) may be performed.
Hereinafter, a surface treatment method for a steam generator heat transfer tube for a reactor according to the present embodiment will be described with reference to the drawings.

Embodiment (Part 1)
In the first embodiment of the present invention, the inner surface of the heat transfer tube is subjected to a blasting process using beads having a small particle diameter, and the blasted heat transfer tube is subjected to high-temperature water in a PWR primary system simulated environment before the start of operation. actual HFT process of distributing, or hot water is immersed in (B, Li, and H ₂ constant concentration dissolved water including. hereinafter the same), or be distributed to hot water on the inner surface of the heat transfer tube Is a surface treatment method for a steam generator heat transfer tube for a nuclear reactor, including a step of forming a film on the inner surface of the heat transfer tube (film treatment step). FIG. 1 schematically shows the method of this embodiment in the order of steps.
In this embodiment, first, the inner surface 4 of the heat transfer tube is blasted. By distorting only the heat transfer tube inner surface 4 by blasting, the surface strain layer 2 is generated. Further, the surface coating 3 is formed by immersing the heat transfer tube in high-temperature water. Alternatively, the formation of the surface film 3 is accelerated by performing a test operation in high-temperature water in the PWR primary system simulated environment before starting operation (film treatment with HFT: Hot Function Test) on the pipe inner surface 4. In the present invention, the high temperature water is usually water at 150 to 400 ° C. By trial operation in high-temperature water before the start of operation, it is possible to increase the diffusion rate associated with the strain in the blast treatment for the formation of the surface film, and to reduce the amount of Ni elution from the heat transfer tube along with the formed film.

As the blasting conditions, the pressure is 3 to 5 kg / cm ² using a blast ball 1 such as glass beads having a particle diameter of 100 to 500 μm, zirconia beads, stainless steel beads, and Ni-based alloy beads as a co-material. Work only on the inner surface of the pipe at a speed of 100 to 500 mm / min. More specifically, it is preferable that the construction is performed using the glass beads 1 of 180 to 250 μm under the conditions of 4 kg / cm ² and construction speed of 200 mm / min.
As conditions for the film treatment process in high-temperature water, the trial run (HFT) conditions before the start of actual machine operation are simulated, for example, PWR primary system simulated environment water (285 ° C, B (boron): 2,300 ppm, Li (lithium): 3 ppm, DH ₂ (dissolved hydrogen): 25 cc / kg) for 2 days (about 50 hours) to form a film on the surface.

Embodiment (2)
In the second embodiment of the present invention, the inner surface of the heat transfer tube is immersed in nitric hydrofluoric acid to remove the film, and the hydrofluoric acid treatment step is brought into contact with an aqueous HNO ₃ (nitric acid) solution to form a film. A surface treatment method including a treatment step (nitric acid treatment step). Here, in addition to the nitric hydrofluoric acid treatment step and the nitric acid treatment step, the heat transfer tube subjected to the nitric acid treatment is put into an actual machine HFT treatment that distributes the high temperature water of the PWR primary system simulation environment before the start of operation, or in high temperature water. A step of forming a film on the inner surface of the heat transfer tube by immersing or circulating high temperature water on the inner surface of the heat transfer tube may be included. FIG. 2 schematically shows the method of this embodiment in the order of steps.

In this embodiment, the inner surface 4 of the heat transfer tube is treated with nitric hydrofluoric acid to dissolve the coating, and then treated with nitric acid to form a Cr-rich coating 6. Furthermore, if necessary, surface film formation can be added by immersion in high-temperature water, or trial operation in high-temperature water (HFT film treatment) in a PWR primary system simulation environment before the start of operation. In the nitric acid treatment process, the amount of Ni elution from the heat transfer tube is reduced by forming a film on the surface of the heat transfer tube with Cr concentrated.
As the nitric hydrofluoric acid treatment step, 1 to 5% HF, with 3 to 30% HNO ₃ aqueous solution, treatment of 1 to 60 minutes at room temperature to 100 ° C. are preferably exemplified.
Further, as the nitric acid treatment step, with 5 to 50% HNO ₃ aqueous solution, it includes treatment conditions 30 to 120 minutes at room temperature to 100 ° C.. More specifically, 10% HNO ₃ aqueous solution, treatment at 50 ° C. for 60 minutes, or 30% HNO ₃ aqueous solution, treatment at 50 ° C. for 60 minutes is preferable.

Embodiment (Part 3)
In the third embodiment of the present invention, the inner surface of the heat transfer tube is immersed in nitric hydrofluoric acid to remove the film, and the nitric hydrofluoric acid step is brought into contact with an aqueous solution of citric acid (or ammonium citrate, the same applies hereinafter). A surface treatment method including a passivating step (citric acid treatment step). Here, the citric acid-treated heat transfer tube is subjected to an actual HFT treatment in which high-temperature water in a PWR primary system simulation environment before operation is circulated, or immersed in high-temperature water, or high-temperature water on the inner surface of the heat-transfer tube Can be included to form a film on the inner surface of the heat transfer tube. FIG. 3 schematically shows the method of this embodiment in the order of steps.

In this embodiment, the inner surface 4 of the heat transfer tube is first brought into contact with nitric hydrofluoric acid to dissolve the surface film, and then brought into contact with citric acid or the like to form the Cr-rich layer 8. Next, the formation of the surface film 3 is added by immersion in high-temperature water or trial operation (HFT film treatment) in high-temperature water in a PWR primary system simulation environment before the start of operation.
In the citric acid treatment step, Cr is concentrated on the surface. Further, as in the first embodiment (part 1), for example, by performing a trial operation (HFT film treatment) in high-temperature water in a PWR primary system simulated environment before starting operation, a surface film is formed from the heat transfer tube. Reduce the amount of Ni dissolved in

As the nitric hydrofluoric acid treatment step, 1 to 5% HF, with 3 to 30% HNO ₃ aqueous solution, treatment of 1 to 60 minutes at room temperature to 100 ° C. are preferably exemplified.
In addition, as the above-mentioned citrate treatment step, treatment conditions of usually 5 to 20% citric acid aqueous solution, room temperature to 100 ° C., and 30 to 150 minutes can be mentioned. More specifically, a treatment condition of 15% aqueous citric acid solution at 65 ° C. for 120 minutes is preferable.
Moreover, when using an ammonium citrate, the processing conditions of 5-20% ammonium dihydrogen citrate aqueous solution, 50-100 degreeC, 30-150 minutes are mentioned. More specifically, a treatment condition of 10% ammonium dihydrogen citrate aqueous solution at 95 ° C. for 120 minutes is preferable.

Embodiment (part 4)
In the fourth embodiment of the present invention, the inner surface of the heat transfer tube is subjected to a blasting process using beads having a small particle diameter, and the HNO ₃ aqueous solution is brought into contact with the inner surface of the blasted heat transfer tube. Forming a nitric acid treatment step. FIG. 4 schematically shows the method of this embodiment in the order of steps.

In this embodiment, the inner surface 4 of the heat transfer tube is first blasted to form the surface strain layer 2. Next, nitric acid treatment is added on the blasted surface to form a dense Cr-rich film 6. Furthermore, if necessary, surface film formation can be added by immersion in high-temperature water, or trial operation in high-temperature water (HFT film treatment) in a PWR primary system simulation environment before the start of operation. By such a process, strain is preliminarily applied by blast treatment, and Ni is eluted from the heat transfer tube by forming a film in which Cr is concentrated on the surface by nitric acid treatment at an accelerated rate from the application of strain during blast treatment. Reduce the amount.
The conditions of the blast treatment step and the nitric acid treatment step are the same as in the above-described embodiment (No. 1) and (No. 2).

Embodiment (Part 5)
According to a fifth aspect of the present invention, the inner surface of the heat transfer tube is subjected to a blasting process using beads having a small particle diameter, and the inner surface of the blasted heat transfer tube is contacted with an aqueous citric acid solution so that the surface is brought into contact. The citric acid treatment step and the citric acid-treated heat transfer tube are used in the actual HFT treatment for circulating the high-temperature water in the PWR primary system simulation environment before the start of operation, or immersed in the high-temperature water, or the inside of the heat transfer tube And a step of forming a film on the inner surface of the heat transfer tube by circulating high-temperature water on the surface. FIG. 5 schematically shows the method of this embodiment in the order of steps.

In this embodiment, the inner surface 4 of the heat transfer tube is first blasted to form the surface strain layer 2. Next, a Cr-rich layer 8 is formed on the blasted surface by treatment with citric acid or the like. Furthermore, the surface film 6 is formed by immersion in high-temperature water or a trial operation (HFT film treatment) in high-temperature water in a PWR primary system simulation environment before the start of operation.
In the treatment method of the present embodiment, the inner surface of the heat transfer tube is preliminarily distorted only in the surface by blasting, and Cr is concentrated on the surface. Furthermore, the amount of Ni elution from the heat transfer tube is formed by forming a surface film by operating with high-temperature water (HFT film treatment) under the simulated PWR primary system before the start of operation as in the case of the first embodiment (Part 1). Reduce.
The conditions of the blasting process and the quenching process are the same as in the first embodiment (part 1) and (part 4).

Embodiment (No. 6)
In the processing method of this embodiment, first, the inner surface 4 of the heat transfer tube is blasted to form the surface strained layer 2. Next, a surface film dissolution treatment with nitric hydrofluoric acid is performed on the blasted surface to reduce the surface roughness due to blasting. The Cr-rich layer 8 is formed by subjecting the surface of the heat transfer tube treated with blasting and nitric hydrofluoric acid to passivation by nitric acid treatment. Furthermore, the surface film 6 is formed by immersion in high-temperature water or a trial operation (HFT film treatment) in high-temperature water in a PWR primary system simulation environment before the start of operation.
In the treatment method of the present embodiment, the inner surface of the heat transfer tube is preliminarily distorted only in the surface by blasting, and Cr is concentrated on the surface. Furthermore, the amount of Ni elution from the heat transfer tube is formed by forming a surface film by operating with high-temperature water (HFT film treatment) under the simulated PWR primary system before the start of operation as in the case of the first embodiment (Part 1). Reduce.
The conditions of the blast treatment process, the nitric hydrofluoric acid treatment process, and the nitric acid treatment process are the same as in the first embodiment (part 1) and (part 2). FIG. 6 schematically shows the method of this embodiment in the order of steps.

Embodiment (Part 7)
In the processing method of this embodiment, first, the inner surface 4 of the heat transfer tube is blasted to form the surface strained layer 2. Next, a surface film dissolution treatment with nitric hydrofluoric acid is performed on the blasted surface to reduce the surface roughness due to blasting. The Cr-rich layer 8 is formed by subjecting the surface of the heat transfer tube treated with blasting and nitric hydrofluoric acid to passivation by treatment with citric acid or the like. Furthermore, the surface film 6 is formed by immersion in high-temperature water or a trial operation (HFT film treatment) in high-temperature water in a PWR primary system simulation environment before the start of operation.
In the treatment method of the present embodiment, the inner surface of the heat transfer tube is preliminarily distorted only in the surface by blasting, and Cr is concentrated on the surface. Furthermore, the amount of Ni elution from the heat transfer tube is formed by forming a surface film by operating with high-temperature water (HFT film treatment) under the simulated PWR primary system before the start of operation as in the case of the first embodiment (Part 1). Reduce.
The conditions of the blast treatment step, the nitric hydrofluoric acid treatment step, and the citric acid treatment step are the same as those in the first embodiment (part 1) and (part 3). FIG. 6 schematically shows the method of this embodiment in the order of steps.
EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not restrict | limited at all by these Examples.

Examples A to N
With the batch type autoclave apparatus shown in FIG. 7, the Ni elution test was performed on the alloy-treated materials subjected to the respective surface treatments corresponding to the above embodiments (No. 1) to (No. 7). As the alloy, TT690 alloy was used.
[Test method]
1) The surface treatment of each of the above embodiments (No. 1) to (No. 7) was performed on the inner surface of the SG heat transfer tube specimen 14 (test materials A to N). In order to form a film, after the surface treatment, the film was once immersed in high temperature water for about 50 hours to form a film on the surface.
2) One end of the SG heat transfer tube 14 was plugged 13 using welding or a swage lock.
3) A fixed amount of PWR primary simulated environmental water 15 (liquid composition: B: 1,200 ppm, Li: 2 ppm, H ₂ : 25 cc / kg) was injected from one side.
4) The other end was closed by closing the stopper 13 using welding or a swage lock.
5) The SG heat transfer tube 14 closed at both ends is immersed in the autoclave 10.
6) Put the autoclave 10 in a high temperature and high pressure environment.
7) Sample PWR primary environmental water (B: 1,200 ppm, Li: 2 ppm, H ₂ : 25cc / kg, temperature: 320 ° C) in the SG heat transfer tube after about 300 hours and 1,000 hours The amount of Ni, Cr and Fe eluted in the sample was measured.
8) The Ni elution amount and elution rate were determined for each of the treated specimens mainly by determining the amount of change in the amount of Ni in the water before the test and after the test for about 300 hours and after the 1,000 hour test. The results are shown in Table 1.

From the above results, it was proved that the Ni elution amount can be reduced by about 1/3 in all of B to N treated with the film, compared to the non-coated film A (reference) in Table 1. .
While the embodiments of the present invention have been described above, the present invention can be variously modified and changed based on the technical idea of the present invention.

  According to the surface treatment method of the present invention, it is possible to reduce the exposure dose of workers by reducing Ni elution from the heat transfer tube as much as possible. Therefore, by applying it to the heat transfer tube of the steam generator for nuclear reactors, it can be expected to greatly contribute to the improvement of the safety of the nuclear power generation system, and the industrial significance is extremely great.

It is the figure which showed typically the method by embodiment (the 1) of this invention in process order. It is the figure which showed typically the method by embodiment (the 2) of this invention in process order. It is the figure which showed typically the method by embodiment (the 3) of this invention in order of a process. It is the figure which showed typically the method by embodiment (the 4) of this invention in order of a process. It is the figure which showed typically the method by embodiment (the 5) of this invention in process order. It is the figure which showed typically the method by embodiment (the 6 and 7) of this invention in order of a process. It is the figure which showed typically the outline at the time of performing Ni elution test using a batch-type autoclave apparatus in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blast ball | bowl 2 Surface distortion layer 3 Film | membrane 4 Pipe inner surface 5 Pipe outer surface 6 Cr rich film 8 Cr rich layer 10 Autoclave 11 Nitrogen 12 Pure water 13 Plug (cap)
14 Heat transfer tube specimen 15 Simulated RCS
16 Mixed gas

Claims (14)

A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
Including a step of blasting the inner surface of the heat transfer tube using beads having a small particle diameter, and a step of forming a film by an actual HFT treatment in which high-temperature water in a PWR primary system simulation environment is circulated before starting operation. A surface treatment method for a steam generator heat transfer tube for a nuclear reactor. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
A step of blasting the inner surface of the heat transfer tube with beads having a small particle diameter;
And a step of forming a film on the inner surface of the heat transfer tube by immersing the blasted heat transfer tube in high temperature water or circulating high temperature water on the inner surface of the heat transfer tube. Surface treatment method for steam generator heat transfer tubes. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
A nitric hydrofluoric acid treatment step for removing the coating by immersing it in nitric hydrofluoric acid on the inner surface of the heat transfer tube, and a passivation treatment step for forming a coating by bringing the heat transfer tube treated with nitric hydrofluoric acid into contact with an aqueous HNO ₃ solution A surface treatment method for a steam generator heat transfer tube for a nuclear reactor.   In addition, the heat transfer tube that has been subjected to the passivating process is immersed in high-temperature HFT treatment that circulates high-temperature water in the PWR primary system simulation environment before the start of operation, or in the heat transfer tube. The method for surface treatment of a steam generator heat transfer tube for a nuclear reactor according to claim 3, further comprising the step of forming a film on the inner surface of the heat transfer tube by circulating high temperature water over the surface. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
A nitric hydrofluoric acid treatment step in which the inner surface of the heat transfer tube is immersed in nitric hydrofluoric acid to remove the film, and the nitric hydrofluoric acid-treated heat transfer tube is brought into contact with an aqueous solution of citric acid or ammonium citrate to passivate the surface. A surface treatment method for a steam generator heat transfer tube for a nuclear reactor.   In addition, the heat transfer tube that has been subjected to the passivating process is an actual HFT process that circulates high-temperature water in the PWR primary system simulated environment before the start of operation, or is immersed in high-temperature water, or the heat transfer tube The method for surface treatment of a steam generator heat transfer tube for a nuclear reactor according to claim 5, further comprising the step of forming a film on the inner surface of the heat transfer tube by circulating high temperature water on the inner surface of the heat transfer tube. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
A step of blasting the inner surface of the heat transfer tube with beads having a small particle diameter;
A surface treatment method for a steam generator heat transfer tube for a nuclear reactor, comprising a passivation treatment step of bringing a HNO ₃ aqueous solution into contact with an inner surface of the blasted heat transfer tube to form a film.   In addition, the heat transfer tubes that have undergone the blasting and passivation treatment steps are immersed in high-temperature water, or an actual HFT treatment that distributes high-temperature water in a PWR primary system simulation environment before the start of operation, or The surface treatment of a steam generator heat transfer tube for a nuclear reactor according to claim 7, comprising a step of forming a film on the inner surface of the heat transfer tube by circulating high temperature water on the inner surface of the heat transfer tube. Method. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
A step of blasting the inner surface of the heat transfer tube with beads having a small particle diameter;
A surface treatment of a steam generator heat exchanger tube for a reactor, comprising the step of bringing the inner surface of the blasted heat transfer tube into contact with an aqueous solution of citric acid or ammonium citrate to passivate the surface Method.   In addition, the heat transfer tube that has been subjected to the blasting and passivating steps, an actual machine HFT treatment that circulates the high-temperature water of the PWR primary system simulation environment before the start of operation, or is immersed in high-temperature water, or 10. The surface of the steam generator heat transfer tube for a reactor according to claim 9, further comprising a step of forming a film on the inner surface of the heat transfer tube by circulating high temperature water on the inner surface of the heat transfer tube. Processing method. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe base alloy,
A step of blasting the inner surface of the heat transfer tube with beads having a fine particle diameter, and a step of nitrating hydrofluoric acid treatment for removing the coating by immersing in nitric hydrofluoric acid on the inner surface of the blasted heat transfer tube, And a passivation treatment step of forming a film by bringing the heat transfer tube treated with nitric hydrofluoric acid into contact with an aqueous HNO ₃ solution.   In addition, heat transfer tubes that have undergone the blasting, nitric hydrofluoric acid treatment, and passivating treatment steps are immersed in high-temperature HFT treatment or high-temperature water that circulates high-temperature water in the PWR primary system simulation environment before the start of operation. The steam generator for a reactor according to claim 11, further comprising: forming a film on the inner surface of the heat transfer tube by circulating high temperature water on the inner surface of the heat transfer tube. Surface treatment method for heat transfer tubes. A surface treatment method for a heat transfer tube of a steam generator for a reactor made of a Ni-Cr-Fe alloy,
A step of blasting the inner surface of the heat transfer tube with beads having a fine particle diameter, and a step of nitrating hydrofluoric acid treatment for removing the coating by immersing in nitric hydrofluoric acid on the inner surface of the blasted heat transfer tube, A method of treating the surface of a steam generator heat transfer tube for a reactor, comprising the step of bringing the nitric hydrofluoric acid-treated heat transfer tube into contact with an aqueous solution of citric acid or ammonium citrate to passivate the surface.   In addition, the heat transfer tubes that have undergone the blasting, nitric hydrofluoric acid, and passivating processes are put into an actual HFT process that distributes high-temperature water in the PWR primary system simulation environment before the start of operation, or in high-temperature water. The steam generation for a nuclear reactor according to claim 13, further comprising a step of forming a film on the inner surface of the heat transfer tube by immersing or circulating high temperature water on the inner surface of the heat transfer tube. Surface treatment method for heat exchanger tubes.

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