[2M18-21] Accident Chemistry 3

[2M19] Investigation of in-reactor cesium chemical behavior in TEPCO’s Fukushima Daiichi Nuclear Power Station accident

(9)Thermodynamics of evaporation of silicon compounds at high temperatures

*Yoshinao Kobayashi¹, Rizky Dwi Septian¹, Shigeru Ueda², Isamu Sato³, Masahiko Ohsaka⁴ (1. Tokyo Institute of Technology, 2. Tohoku University, 3. Tokyo City University, 4. Japan Atomic Energy Agency)

Keywords:Insoluble cesium particles , cesium silicate, thermodynamics, vapor pressure

The vapor pressures of SiO2 and Si(OH)4 have been thermodynamically evaluated to elucidate the formation mechanism of insoluble radioactive particles. The experimental condition of chemical equilibrium technique to determine the activities of Cs2O and SiO2 in the Cs2O-SiO2 system which is the basic system of these particles has been comprehensively established.