Estimation of Cs distribution and characteristics in the reactor under severe accident, 3; Chemical forms of Cs chemisorbed products

Suzuki, Eriko   ; Nakajima, Kunihisa  ; Miwa, Shuhei  ; Osaka, Masahiko  ; Hashimoto, Naoyuki*; Isobe, Shigehito*; Oka, Hiroshi*   

In order to evaluate the properties of chemisorbed cesium (Cs) onto the structural materials in nuclear reactors during severe accidents, temperature dependency of the chemical forms of Cs chemisorbed compounds was investigated based on the compilation of previous studies, the simulation tests of Cs chemisorption onto stainless steel, the acquisition of thermodynamic data and the thermodynamic equilibrium calculations, and the microstructure observation of chemical forms inside the oxide layer. It was revealed that the different Cs chemisorbed compounds were formed depending on the temperature conditions, such as Cs-Fe-O at 873-973 K, Cs-Fe-Si-O at 973-1273 K and Cs-Si-O at 1073-1273 K.