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Nobuyoshi Hara - One of the best experts on this subject based on the ideXlab platform.
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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....
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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...
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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...
Yoichi Wada - One of the best experts on this subject based on the ideXlab platform.
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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....
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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...
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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...
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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...
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hydrazine and hydrogen co injection to mitigate stress corrosion cracking of structural materials in Boiling Water Reactors iii effects of adding hydrazine on zircaloy 2 corrosion
Journal of Nuclear Science and Technology, 2006Co-Authors: Hidetoshi Karasawa, Kazushige Ishida, Yoichi Wada, Motohiro Aizawa, Motomasa Fuse, Eiichi Kadoi, Masao Endou, Yoshitaka Nishino, Hideki TakiguchiAbstract:The effects of hydrazine on the corrosion of Zircaloy-2 were examined in supercritical Water. Hydrazine could be used as a reducing agent to control the corrosive environment for the coolant of Boiling Water Reactors (BWRs). Before the corrosion test, the applicability of supercritical Water for corrosion testing of zirconium alloys was studied. Supercritical Water was found to be a useful solvent for testing corrosion based on the following facts: (I) the weight gain of Zircaloy-2 in supercritical Water followed the same cubic law with the activation energy of 133 kJ/mol as that in Water and steam did, and (2) the weight gain in supercritical Water at 723 K and 24.5 MPa was more than 8 times greater than that in Water at 561 K and 7.8 MPa depending on immersion time. The corrosion tests in supercritical Water at 723 K and 24.5 MPa under γ-irradiation for 1,000h were conducted to study the effects of adding nitrogen and ammonia on the corrosion of Zircaloy-2. Nitrogen and ammonia are decomposed products of hydrazine. The measured weight gain, oxide film thickness, and amount of hydrogen pick-up had slight differences between cases with and without the additives. Based on these data, it was concluded adding hydrazine to the coolant has little influence on the corrosion of Zircaloy-2 used in BWR cores.
Masahiko Tachibana - One of the best experts on this subject based on the ideXlab platform.
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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....
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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...
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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...
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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...
Kazushige Ishida - One of the best experts on this subject based on the ideXlab platform.
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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....
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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...
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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...
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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...
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hydrazine and hydrogen co injection to mitigate stress corrosion cracking of structural materials in Boiling Water Reactors iii effects of adding hydrazine on zircaloy 2 corrosion
Journal of Nuclear Science and Technology, 2006Co-Authors: Hidetoshi Karasawa, Kazushige Ishida, Yoichi Wada, Motohiro Aizawa, Motomasa Fuse, Eiichi Kadoi, Masao Endou, Yoshitaka Nishino, Hideki TakiguchiAbstract:The effects of hydrazine on the corrosion of Zircaloy-2 were examined in supercritical Water. Hydrazine could be used as a reducing agent to control the corrosive environment for the coolant of Boiling Water Reactors (BWRs). Before the corrosion test, the applicability of supercritical Water for corrosion testing of zirconium alloys was studied. Supercritical Water was found to be a useful solvent for testing corrosion based on the following facts: (I) the weight gain of Zircaloy-2 in supercritical Water followed the same cubic law with the activation energy of 133 kJ/mol as that in Water and steam did, and (2) the weight gain in supercritical Water at 723 K and 24.5 MPa was more than 8 times greater than that in Water at 561 K and 7.8 MPa depending on immersion time. The corrosion tests in supercritical Water at 723 K and 24.5 MPa under γ-irradiation for 1,000h were conducted to study the effects of adding nitrogen and ammonia on the corrosion of Zircaloy-2. Nitrogen and ammonia are decomposed products of hydrazine. The measured weight gain, oxide film thickness, and amount of hydrogen pick-up had slight differences between cases with and without the additives. Based on these data, it was concluded adding hydrazine to the coolant has little influence on the corrosion of Zircaloy-2 used in BWR cores.
Ryosuke Shimizu - One of the best experts on this subject based on the ideXlab platform.
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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....
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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...
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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...