FP chemistry in a high temperature region of LWR under a severe accident, 5; Formalization of the HAXPES analysis method for Cs compound using DFT calculation

Suzuki, Chikashi ; Kobata, Masaaki  ; Nakajima, Kunihisa  ; Okane, Tetsuo  ; Osaka, Masahiko  

In order to elucidate Cs chemisorption on structural materials in reactors for the decommissioning of Fukushima Dai-ichi NPS (1F), Cs compounds formed by Cs chemisorption are evaluated using HAXPES. In the valence sate range of HAXPES, Cs 5p component is large, and it splits into Cs 5p and Cs 5p due to spin-orbit interaction, but some peaks attributed to Cs 5p and Cs 5p overlap. In order to analyze HAXPES spectrum using DFT calculation, it is necessary to separate the peak of Cs 5p component into Cs 5p and Cs 5p . We formulated a scheme to separate the peak of the Cs 5p component calculated by DFT calculation and applied to analysis of the HAXPES spectrum of CsSiFeO. The spectrum obtained by this scheme was well reproduced that obtained by HAXPES measurement.