Modelling and numerical calculation of mass transfer phenomena between fast reactor fuel cladding tube and liquid Na

Otsuka, Satoshi   ; Tanno, Takashi  ; Oka, Hiroshi   ; Yano, Yasuhide  ; Uwaba, Tomoyuki ; Kaito, Takeji ; Furukawa, Tomohiro  ; Kato, Shoichi 

Maximum temperature of ODS steel cladding tube for long life fast reactor fuel is very high (approximately 700C) 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.