Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Otsuka, Satoshi; Tanno, Takashi; Oka, Hiroshi; Yano, Yasuhide; Uwaba, Tomoyuki; Kaito, Takeji; Furukawa, Tomohiro; Kato, Shoichi
no journal, ,
Maximum temperature of ODS steel cladding tube for long life fast reactor fuel is very high (approximately 700
C) in normal operation condition. It was reported that, in reactor operation, mass transfer phenomena (dissolution, deposition, penetration) took place as a result of increased solubility of steel constituent elements in liquid Na. The driving force of these phenomena is the chemical potential gap of solute elements in steel and liquid Na, which is dependent of not only temperature but also other factors such as impurity concentrations in Liquid Na. For appropriately evaluating experimental data and predicting the corrosion behavior in actual plant, it is required to list up the key factors including other factors than temperature and residence time and understand the effects of these factors. In this study, transfer behavior of Cr (main alloying element of ODS steel) is discussed; modelling and numerical calculation were carried out on Cr dissolution behavior from fast reactor fuel cladding tube into liquid Na.
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Kaito, Takeji
no journal, ,
no abstracts in English
Yuzawa, Sho*; Yabuuchi, Kiyohiro*; Kimura, Akihiko*; Sakamoto, Kan*; Hirai, Mutsumi*; Yamashita, Shinichiro
no journal, ,
Oxide dispersion strengthened steel with high Cr and Al concentration in chemical composition (FeCrAl-ODS steel) has been proposed as a promising candidate for the accident tolerant fuel cladding of light water reactors (LWRs) because of their excellent oxidation and corrosion resistance under high temperature water and steam environments. Neither there are no sufficient knowledge on welding technology of FeCrAl-ODS nor it is known that aluminum addition remarkably degrades the weldability of the ODS steel. In this study, electron beam (EB) welding and tungsten inert gas (TIG) welding were applied to the SUS430 endcap welding to cladding tube made of FeCrAl-ODS steel and performed the bonding strength and corresponding damage structure evaluations at the bonding part.
Oba, Yojiro; Sasaki, Hirokazu*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Onuma, Masato*; Sugiyama, Masaaki*
no journal, ,
no abstracts in English
Kaneda, Tomohiro*; Yokoyama, Kenichi*; Ishijima, Yasuhiro; Ueno, Fumiyoshi; Abe, Hitoshi
no journal, ,
In spent nuclear fuel reprocessing plant, Zr/Ta dissimilar metal joint is used for connect between different devices. And it is known that Zr and Ta have susceptibility of hydrogen embrittlement. The other hand, Zr and Ta are alloyed in the dissimilar joint and it is not clear that the hydrogen embrittlement behavior of the Zr-Ta alloy. This study aims to elucidate the hydrogen embrittle behavior of the Zr-Ta alloy. Tensile tests and X-ray diffraction (XRD) were carried out after hydrogen charging in 0.9% NaCl solution. The zirconium hydride was detected by XRD analysis but embrittlement was not shown by tensile tests. However, brittle fracture patterns were observed by SEM observation at the fracture surface the specimen after tensile test. It is consider that these results suggest the zirconium hydride that formed by hydrogen charging dominates the hydrogen embrittlement behavior of the Zr-Ta alloy.
Ebihara, Kenichi; Suzudo, Tomoaki; Yamaguchi, Masatake
no journal, ,
no abstracts in English
Taniguchi, Keisuke*; Onitsuka, Takashi*; Fukumoto, Kenichi*; Suzudo, Tomoaki
no journal, ,
It is known that a cause of irradiation hardening of nuclear materials by neutron irradiation can be ascribed to voids as an obstacle against dislocation motion. In this research, molecular dynamics (MD) simulations were exploited in order to analyze the dynamical reaction mechanism at the atomic level of the screw dislocation and void in BCC pure Fe. In particular, the relationship between the dislocation-void contact position and the strength of interaction was analyzed. As a result, it turned out that there is a rule between the contact position and the shear stress.