scholarly journals Zeta Potentials of Magnetite Particles and Alloy 690 Surfaces in Alkaline Solutions

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3999
Author(s):  
Ji-Min Lee ◽  
Dong-Seok Lim ◽  
Soon-Hyeok Jeon ◽  
Do Haeng Hur
Keyword(s):  
Magnetite Nanoparticles ◽  
Ph Value ◽  
Alkaline Solutions ◽  
Empirical Formulas ◽  
Pressurized Water ◽  
Zeta Potentials ◽  
Alloy 690 ◽  
Magnetite Particles ◽  
Water Reactors ◽  
And Performance

Magnetite particles deposited on the secondary side of a steam generator (SG) can degrade the integrity and performance of pressurized water reactors. Therefore, it is necessary to produce the data of fundamental interfacial electrokinetic properties of magnetite particles and SG tube materials. This study investigated the zeta potentials of magnetite nanoparticles and Alloy 690 surfaces, which were dependent on the pH value, pH agent, and the presence of NaCl. The zeta potentials of the magnetite nanoparticles increased in the negative direction as the pH increased, regardless of the pH agent. At the same pH value, the absolute values of the zeta potentials with different pH agents were: ethanolamine < ammonia < morpholine. In the presence of NaCl, the zeta potentials of the particles further increased negatively. The meaning of the measured zeta potentials was discussed in terms of the dispersion stability and the agglomeration of the particles. Based on the relationship between the zeta potentials of the particles and Alloy 690 surfaces, the magnetite deposition on Alloy 690 was also discussed. Furthermore, the empirical formulas for the pH-dependent zeta potentials of magnetite particles in each alkaline solution were suggested.

scholarly journals Effects of Advanced Amines on Magnetite Deposition of Steam Generator Tubes in Secondary System

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 514
Author(s):  
Yong-Beom Lee ◽  
Ji-Min Lee ◽  
Do-Haeng Hur ◽  
Jong-Hyeon Lee ◽  
Soon-Hyeok Jeon
Keyword(s):  
Steam Generator ◽  
Ph Value ◽  
Secondary System ◽  
Pressurized Water ◽  
Zeta Potentials ◽  
Alloy 690 ◽  
Environmental Treatment ◽  
Average Porosity ◽  
Magnetite Particles ◽  
Water Reactors

Ethanolamine (ETA) is widely used to control the pH value in the secondary water of pressurized water reactors. However, it is necessary to consider other advanced amines which can replace ETA due to its serious human hazards and environmental treatment problems. The purpose of this study is to contemplate the effects of three advanced amines (ETA, 3-methoxypropylamine (MPA), and dimethylamine (DMA)) on the magnetite deposition behavior of a thermally treated (TT) Alloy 690 tubes by using a steam generator (SG) tube fouling loop in simulated secondary water. All particles were identified as a magnetite and were polyhedral or spherical in shape. When using ETA, MPA, and DMA, the average porosity of the deposits was about 34.7%, 33.0%, and 24.6%, respectively. The amount of deposits was largest when ETA was added, and it decreased by 41% when adding MPA and 55% when adding DMA. The mechanism of magnetite deposition was discussed in terms of zeta potentials of both the magnetite particles and the Alloy 690TT surface and magnetite solubility depending on the amines. To compare the potential for replacing ETA with other advanced amines, the various factors such as SG integrity, human hazards, and environmental treatment problems were discussed.

scholarly journals Micro-Galvanic Corrosion of Steam Generator Materials within Pores of Magnetite Flakes in Alkaline Solutions

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 899 ◽  
Author(s):  
Soon-Hyeok Jeon ◽  
Geun Song ◽  
Do Hur
Keyword(s):  
Steam Generator ◽  
Galvanic Corrosion ◽  
Area Ratio ◽  
Corrosion Products ◽  
Alkaline Solutions ◽  
Galvanic Coupling ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Alloy 690 ◽  
Water Reactors

In secondary coolant system of the pressurized water reactors, the reduced corrosion products such as metallic Cu and Pb particles were accumulated in the pores of the magnetite flakes and electrically contacted to the steam generator materials. The micro-galvanic corrosion behavior of steam generator materials (steam generator tube materials: Alloy 600 and Alloy 690, steam generator tube sheet materials: SA508 Gr.3) contacted to the corrosion products (magnetite, Cu, and Pb) was investigated in an alkaline solution. The steam generator materials considered in this study were all the anodic elements of the galvanic pair because their corrosion potentials were lower than those of the corrosion products. The corrosion rate of the steam generator materials was increased by the galvanic coupling with the each corrosion products, and was more accelerated with increasing the area ratio of the corrosion products to the steam generator materials. Among the corrosion products, Cu has the largest galvanic effect on steam generator materials in the pores when area ratio of cathode to anode is 10.

INCONEL FILLER METAL 52

Alloy Digest ◽  
1992 ◽  
Vol 41 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Arc Welding ◽  
Filler Metal ◽  
Pressurized Water Reactors ◽  
Pressurized Water ◽  
High Chromium ◽  
Inconel Alloy ◽  
Gas Tungsten Arc ◽  
Alloy 690 ◽  
Water Reactors

Abstract INCONEL FILLER METAL 52 is a high chromium filler metal for gas-metal-arc and gas-tungsten-arc welding of Inconel Alloy 690 (See Alloy Digest Ni-266, March 1981). Higher chromium is beneficial in resisting stress-corrosion cracking in high purity water for pressurized water reactors and for resistance to oxidizing acids. This datasheet provides information on composition and tensile properties. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-412. Producer or source: Inco Alloys International Inc..

INCONEL WELDING ELECTRODE 152

Alloy Digest ◽  
1992 ◽  
Vol 41 (7) ◽  
Keyword(s):  
Arc Welding ◽  
Pressurized Water Reactors ◽  
Shielded Metal Arc Welding ◽  
Pressurized Water ◽  
High Chromium ◽  
Inconel Alloy ◽  
Metal Arc Welding ◽  
Alloy 690 ◽  
Water Reactors ◽  
Welding Electrode

Abstract INCONEL WELDING ELECTRODE 152 is a high chromium rod for shielded-metal-arc welding of Inconel Alloy 690 (Alloy Digest Ni-266, March 1981). Higher chromium is beneficial in resisting stress-corrosion cracking in high purity water for pressurized water reactors and for resistance to oxidizing acids. This datasheet provides information on composition and tensile properties. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-406. Producer or source: Inco Alloys International Inc..

Assessment of Post-CHF Heat Transfer Models for the SPACE Code

2009 ◽  
Author(s):  
K. Y. Choi ◽  
B. J. Yun ◽  
H. S. Park ◽  
S. K. Moon ◽  
K. D. Kim
Keyword(s):  
Heat Transfer ◽  
Mode Selection ◽  
Film Boiling ◽  
Model Assessment ◽  
Field Equations ◽  
Pressurized Water ◽  
Water Reactors ◽  
And Performance ◽  
Physical Phenomena ◽  
Transfer Models

The SPACE (Safety and Performance Analysis Code) which is based on a multi-dimensional two-fluid, three-field model is under development for a licensing purpose of pressurized water reactors in Korea. A total of 12 wall-to-fluid heat transfer modes were defined and a heat transfer mode selection logic was developed according to the noncondensable gas quality, the void fraction, the degree of subcooling and the wall temperature. Among the constitutive equations of the SPACE code, post-CHF heat transfer models are considered to have the most significant uncertainties because their physical phenomena are not fully understood yet. Though a variety of models and correlations for the post-CHF heat transfer are available, there is no reliable model to reproduce the heat transfer rate as realistically as possible. Several post-CHF heat transfer models are implemented into the SPACE code; critical heat, transition and film boiling models. The present paper describes the model assessment progress which was done for the transition and film boiling models of the SPACE code. A heat flux partition into the continuous liquid, entrained droplet and vapor fields should be taken into account in order to be in line with physical phenomena as the SPACE code has three-field equations in its hydraulic solver. Existing energy partitioning methods were peer-reviewed in order to determine the best model which can be applicable to the SPACE code. The present work will help to consolidate the developed wall-to-fluid heat transfer package of the SPACE code.

The Stress Corrosion Cracking Behavior of Alloys 690 and 152 Weld in a PWR Environment

2008 ◽  
Author(s):  
B. Alexandreanu ◽  
O. K. Chopra ◽  
W. J. Shack
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Water Environment ◽  
Corrosion Cracking ◽  
Pressurized Water ◽  
Cracking Behavior ◽  
Alloy 690 ◽  
Primary Water ◽  
Cold Rolled ◽  
Water Reactors

Alloys 690 and 152 are the replacement materials of choice for Alloys 600 and 182, respectively. The latter two alloys are used as structural materials in pressurized water reactors (PWRs) and have been found to undergo stress corrosion cracking (SCC). The objective of this work is to determine the crack growth rates (CGRs) in a simulated PWR water environment for the replacement alloys. The study involved Alloy 690 cold-rolled by 26% and a laboratory-prepared Alloy 152 double-J weld in the as-welded condition. The experimental approach involved pre-cracking in a primary water environment and monitoring the cyclic CGRs to determine the optimum conditions for transitioning from the fatigue transgranular to intergranular SCC fracture mode. The cyclic CGRs of cold-rolled Alloy 690 showed significant environmental enhancement, while those for Alloy 152 were minimal. Both materials exhibited SCC of 10−11 m/s under constant loading at moderate stress intensity factors. The paper also presents tensile property data for Alloy 690TT and Alloy 152 weld in the temperature range 25–870°C.

JESSOP-SAVILLE ZIRCONIUM ALLOY

Alloy Digest ◽  
1965 ◽  
Vol 14 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Zirconium Alloy ◽  
Heat Treating ◽  
Pressurized Water Reactors ◽  
Neutron Absorption ◽  
High Melting Point ◽  
Absorption Properties ◽  
Pressurized Water ◽  
Excellent Corrosion Resistance ◽  
Water Reactors

Abstract JESSOP-SAVILLE ZIRCONIUM Alloy has a high melting point and possesses excellent corrosion resistance coupled with low neutron absorption properties. It is equivalent to ZIRCALOY 2. It is recommended for pressurized water reactors. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Zr-2. Producer or source: Jessop-Saville Ltd, Brightside Works.

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