The Experts below are selected from a list of 380160 Experts worldwide ranked by ideXlab platform
Masahiko Tachibana - One of the best experts on this subject based on the ideXlab platform.
-
Cathodic polarization curves of the oxygen reduction reaction on various Structural Materials of boiling water reactors in high temperature-high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:Cathodic polarization curves of the O2 reduction reaction were measured by using electrodes made from typical Structural Materials of boiling water reactors (BWRs) to evaluate the effects of kind of material on the electrochemical corrosion potential (ECP) calculation. To estimate ECPs at any region in the BWRs on the basis of the BWR environmental conditions, anodic and cathodic polarization curves should be obtained in advance under relevant conditions. The concentration of oxidants such as O2 and H2O2 in coolant changes depending on the region in which they exist. As well, reduction reaction rates might differ depending on the kind of Materials. In this work, the cathodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in high purity water at 553 K with different O2 concentrations and compared with those of type 304 SS (304 SS). The results showed that the cathodic polarization curves differed depending on the kind of Materials at the activation-controlled region....
-
determining factors for anodic polarization curves of typical Structural Materials of boiling water reactors in high temperature high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:In order to examine the anodic polarization characteristics of typical Structural Materials of boiling water reactors (BWRs), the anodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in deaerated high purity water at 553 K using the previously reported measurement method which was confirmed suitable for high temperature – high purity water. In order to specify which constituent element determines the dissolution characteristics of these Materials, the anodic polarization curves of pure iron, pure nickel, and pure chromium were also surveyed. The anodic polarization curve of 316L SS was determined to have active, passive, and transpassive states which were the same as type 304 SS (304 SS) showed. But, Alloy 182 had different polarization characteristics especially near the corrosion potential as it had no active state. From comparison results of the polarization characteristics of these Materials and their constituent elements, the corrosion characteristics of these...
-
hydrazine and hydrogen co injection to mitigate stress corrosion cracking of Structural Materials in boiling water reactors iv reaction mechanism and plant feasibility analysis
Journal of Nuclear Science and Technology, 2007Co-Authors: Yoichi Wada, Masahiko Tachibana, Kazushige Ishida, Motohiro Aizawa, Motomasa Fuse, Eiichi Kadoi, Hideki TakiguchiAbstract:A calculation model has been developed in order to evaluate effectiveness of hydrazine and hydrogen co-injection (HHC) into reactor water for mitigation of intergranular stress corrosion cracking of Structural Materials used in boiling water reactors (BWRs). The HHC uses the strong reducing power of hydrazine radical, which is produced in the downcomer region under irradiation by γ-rays and neutrons. Some reactions and their reaction rate constants were determined based on experiments which were carried out in aerated water, hydrogenated water, and deaerated water. The calculated results were in good agreement with experimental data by a factor of two. The model was applied to a BWR and it was found that the HHC cut oxygen and hydrogen peroxide amounts dissolved in reactor water more effectively than hydrogen water chemistry alone. Thus, the required amount of hydrogen for hydrazine injection was much lower than that for hydrogen water chemistry. Consequently, electrochemical corrosion potential of struct...
Yoichi Wada - One of the best experts on this subject based on the ideXlab platform.
-
Cathodic polarization curves of the oxygen reduction reaction on various Structural Materials of boiling water reactors in high temperature-high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:Cathodic polarization curves of the O2 reduction reaction were measured by using electrodes made from typical Structural Materials of boiling water reactors (BWRs) to evaluate the effects of kind of material on the electrochemical corrosion potential (ECP) calculation. To estimate ECPs at any region in the BWRs on the basis of the BWR environmental conditions, anodic and cathodic polarization curves should be obtained in advance under relevant conditions. The concentration of oxidants such as O2 and H2O2 in coolant changes depending on the region in which they exist. As well, reduction reaction rates might differ depending on the kind of Materials. In this work, the cathodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in high purity water at 553 K with different O2 concentrations and compared with those of type 304 SS (304 SS). The results showed that the cathodic polarization curves differed depending on the kind of Materials at the activation-controlled region....
-
determining factors for anodic polarization curves of typical Structural Materials of boiling water reactors in high temperature high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:In order to examine the anodic polarization characteristics of typical Structural Materials of boiling water reactors (BWRs), the anodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in deaerated high purity water at 553 K using the previously reported measurement method which was confirmed suitable for high temperature – high purity water. In order to specify which constituent element determines the dissolution characteristics of these Materials, the anodic polarization curves of pure iron, pure nickel, and pure chromium were also surveyed. The anodic polarization curve of 316L SS was determined to have active, passive, and transpassive states which were the same as type 304 SS (304 SS) showed. But, Alloy 182 had different polarization characteristics especially near the corrosion potential as it had no active state. From comparison results of the polarization characteristics of these Materials and their constituent elements, the corrosion characteristics of these...
-
hydrazine and hydrogen co injection to mitigate stress corrosion cracking of Structural Materials in boiling water reactors iv reaction mechanism and plant feasibility analysis
Journal of Nuclear Science and Technology, 2007Co-Authors: Yoichi Wada, Masahiko Tachibana, Kazushige Ishida, Motohiro Aizawa, Motomasa Fuse, Eiichi Kadoi, Hideki TakiguchiAbstract:A calculation model has been developed in order to evaluate effectiveness of hydrazine and hydrogen co-injection (HHC) into reactor water for mitigation of intergranular stress corrosion cracking of Structural Materials used in boiling water reactors (BWRs). The HHC uses the strong reducing power of hydrazine radical, which is produced in the downcomer region under irradiation by γ-rays and neutrons. Some reactions and their reaction rate constants were determined based on experiments which were carried out in aerated water, hydrogenated water, and deaerated water. The calculated results were in good agreement with experimental data by a factor of two. The model was applied to a BWR and it was found that the HHC cut oxygen and hydrogen peroxide amounts dissolved in reactor water more effectively than hydrogen water chemistry alone. Thus, the required amount of hydrogen for hydrazine injection was much lower than that for hydrogen water chemistry. Consequently, electrochemical corrosion potential of struct...
Nobuyoshi Hara - One of the best experts on this subject based on the ideXlab platform.
-
Cathodic polarization curves of the oxygen reduction reaction on various Structural Materials of boiling water reactors in high temperature-high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:Cathodic polarization curves of the O2 reduction reaction were measured by using electrodes made from typical Structural Materials of boiling water reactors (BWRs) to evaluate the effects of kind of material on the electrochemical corrosion potential (ECP) calculation. To estimate ECPs at any region in the BWRs on the basis of the BWR environmental conditions, anodic and cathodic polarization curves should be obtained in advance under relevant conditions. The concentration of oxidants such as O2 and H2O2 in coolant changes depending on the region in which they exist. As well, reduction reaction rates might differ depending on the kind of Materials. In this work, the cathodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in high purity water at 553 K with different O2 concentrations and compared with those of type 304 SS (304 SS). The results showed that the cathodic polarization curves differed depending on the kind of Materials at the activation-controlled region....
-
determining factors for anodic polarization curves of typical Structural Materials of boiling water reactors in high temperature high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:In order to examine the anodic polarization characteristics of typical Structural Materials of boiling water reactors (BWRs), the anodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in deaerated high purity water at 553 K using the previously reported measurement method which was confirmed suitable for high temperature – high purity water. In order to specify which constituent element determines the dissolution characteristics of these Materials, the anodic polarization curves of pure iron, pure nickel, and pure chromium were also surveyed. The anodic polarization curve of 316L SS was determined to have active, passive, and transpassive states which were the same as type 304 SS (304 SS) showed. But, Alloy 182 had different polarization characteristics especially near the corrosion potential as it had no active state. From comparison results of the polarization characteristics of these Materials and their constituent elements, the corrosion characteristics of these...
Kazushige Ishida - One of the best experts on this subject based on the ideXlab platform.
-
Cathodic polarization curves of the oxygen reduction reaction on various Structural Materials of boiling water reactors in high temperature-high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:Cathodic polarization curves of the O2 reduction reaction were measured by using electrodes made from typical Structural Materials of boiling water reactors (BWRs) to evaluate the effects of kind of material on the electrochemical corrosion potential (ECP) calculation. To estimate ECPs at any region in the BWRs on the basis of the BWR environmental conditions, anodic and cathodic polarization curves should be obtained in advance under relevant conditions. The concentration of oxidants such as O2 and H2O2 in coolant changes depending on the region in which they exist. As well, reduction reaction rates might differ depending on the kind of Materials. In this work, the cathodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in high purity water at 553 K with different O2 concentrations and compared with those of type 304 SS (304 SS). The results showed that the cathodic polarization curves differed depending on the kind of Materials at the activation-controlled region....
-
determining factors for anodic polarization curves of typical Structural Materials of boiling water reactors in high temperature high purity water
Journal of Nuclear Science and Technology, 2012Co-Authors: Masahiko Tachibana, Kazushige Ishida, Ryosuke Shimizu, Yoichi Wada, Nobuyoshi HaraAbstract:In order to examine the anodic polarization characteristics of typical Structural Materials of boiling water reactors (BWRs), the anodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in deaerated high purity water at 553 K using the previously reported measurement method which was confirmed suitable for high temperature – high purity water. In order to specify which constituent element determines the dissolution characteristics of these Materials, the anodic polarization curves of pure iron, pure nickel, and pure chromium were also surveyed. The anodic polarization curve of 316L SS was determined to have active, passive, and transpassive states which were the same as type 304 SS (304 SS) showed. But, Alloy 182 had different polarization characteristics especially near the corrosion potential as it had no active state. From comparison results of the polarization characteristics of these Materials and their constituent elements, the corrosion characteristics of these...
-
hydrazine and hydrogen co injection to mitigate stress corrosion cracking of Structural Materials in boiling water reactors iv reaction mechanism and plant feasibility analysis
Journal of Nuclear Science and Technology, 2007Co-Authors: Yoichi Wada, Masahiko Tachibana, Kazushige Ishida, Motohiro Aizawa, Motomasa Fuse, Eiichi Kadoi, Hideki TakiguchiAbstract:A calculation model has been developed in order to evaluate effectiveness of hydrazine and hydrogen co-injection (HHC) into reactor water for mitigation of intergranular stress corrosion cracking of Structural Materials used in boiling water reactors (BWRs). The HHC uses the strong reducing power of hydrazine radical, which is produced in the downcomer region under irradiation by γ-rays and neutrons. Some reactions and their reaction rate constants were determined based on experiments which were carried out in aerated water, hydrogenated water, and deaerated water. The calculated results were in good agreement with experimental data by a factor of two. The model was applied to a BWR and it was found that the HHC cut oxygen and hydrogen peroxide amounts dissolved in reactor water more effectively than hydrogen water chemistry alone. Thus, the required amount of hydrogen for hydrazine injection was much lower than that for hydrogen water chemistry. Consequently, electrochemical corrosion potential of struct...
Thomas Bauer - One of the best experts on this subject based on the ideXlab platform.
-
molten chloride salts for next generation concentrated solar power plants mitigation strategies against corrosion of Structural Materials
Solar Energy Materials and Solar Cells, 2019Co-Authors: Wenjin Ding, A Jianu, Alexander Bonk, A Weisenburger, Thomas BauerAbstract:Abstract Molten chloride salts are promising advanced high-temperature (400–800 °C) thermal energy storage (TES) and heat transfer fluid (HTF) Materials in next generation concentrated solar power (CSP) plants for higher energy conversion efficiencies. However, severe corrosion of Structural Materials in contact with molten chloride salts is one of the most critical challenges limiting their applications at elevated temperatures. In this work, two corrosion mitigation strategies are investigated to alleviate the hot corrosion of Structural Materials in molten chloride salts: (1) adding corrosion inhibitor and (2) using a Fe-Cr-Al alloy with a protective alumina layer on the surface after pre-oxidation. Three commercial high temperature Fe-Cr-Ni alloys (SS 310, Incoloy® 800 H and Hastelloy® C-276) were exposed to molten MgCl2-NaCl-KCl (60–20–20 mol%) mixed salts with 1 wt% Mg as corrosion inhibitor, for 500 h at 700 °C under inert atmosphere. By addition of the Mg inhibitor, the corrosion rates of the studied alloys were found to be significantly reduced, more precisely by ~ 83% for SS 310, ~ 70% for In 800 H and ~ 94% for Ha C-276 compared with the exposure tests without Mg addition. The corrosion mitigation mechanism of Fe-Cr-Ni based alloys in molten chloride salts by adding Mg is discussed based on corrosion thermodynamics. To assess the second mitigation strategy two pre-oxidized alumina forming Fe-Cr-Al alloys were exposed to the same molten chloride salts without Mg corrosion inhibitor under the same conditions. It is observed that the adherent alumina scales can effectively inhibit the dissolution of Cr and Fe and the bulk penetration of corrosive impurities. Overall, both strategies offer enormous potential for enhancing the expected lifetime of commercial alloys in molten chloride salts.
