Growing Mechanism of Dendritic Oxide during Sodium Combustion
Liquid sodium is used as the coolant of the fast reactor (FR). It has superior thermal medium properties, however the chemical reactivity with water and oxygen is very high. More physical and chemical understanding of the reaction phenomena is desired for developing the FR system of practical use, as well as more mechanistic analysis for accidents. Especially oxidation in the first step of sodium combustion is significant for the aspect of reaction continuity. The purpose of this study is to understand oxidation behavior of sodium precisely for FR safety against sodium combustion. In our previous study, it was recognized that dendritic oxide took an important role for the combustion reaction such as supplying the sodium to the reaction interface. In this study, we proposed a mechanistic model of supplying liquid sodium through the dendritic oxide based on the observation result of the growing behavior of dendritic oxide during combustion. In this model we made an attention to the kinds of chemical compounds. Oxygen taken in the oxides changes the kind of sodium oxides after first chemical reaction. The formation of sodium peroxides can provide the sodium supplying route in the dendritic oxide. On the other hand the formation of sodium monoxide will block sodium supplying. The kinds of chemical compounds were decided by the Gibbs’s free energy of thermodynamics in the reaction field such as temperature and oxygen concentration. This mechanistic model can explain the oxidation behavior consistently with the observation results.
Sodium FR Combustion Oxidation Dendritic oxide
Masahiro Nishimura Hideki Kamide Ken-ichiro Sugiyama Shiro Otake
Japan Atomic Energy Agency 4002 Narita-cho, O-arai-machi, Ibaraki,311-1393, Japan Hokkaido University Kita8 Nishi5 Kita-ku Sapporo Hokkaido Japan
国际会议
上海
英文
1723-1733
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）