X-ray analysis for radioactive particulates from Fukushima-Daiichi Nuclear Power Plant using synchrotron radiation at SPring-8

Kobayashi, Toru ; Kobata, Masaaki  ; Tanida, Hajime  ; Fujimori, Shinichi   ; Tsuji, Takuya  ; Fukuda, Tatsuo  ; Shibata, Goro ; Kawasaki, Ikuto  ; Doi, Reisuke  ; Okamoto, Yoshihiro  ; Okane, Tetsuo  ; Yaita, Tsuyoshi; Satou, Yukihiko   ; Suzuki, Shingo ; Maeda, Koji  

By the 2011 Tohoku earthquake and tsunami in the northeast area of Japan, Fukushima Daiichi Nuclear Power Plant (1F) lost all electric supplies, and Unit 1, 2, and 3 were seriously damaged. These Units melted down, resulting in a large amount of debris inside their Primary Containment Vessels (PCVs). However, the nature of the debris is not well understood due to the difficulties in collecting samples from inside the PCVs. On the other hand, micron-sized radioactive particulates were collected during an investigation inside the PCVs. These particulates contain important information for understanding the characteristics of the debris. We performed X-ray fluorescence (XRF), X-ray absorption spectroscopy (XAS), and X-ray diffraction (XRD) analyses on the radioactive particulates collected during an investigation inside the 1F Unit2 PCV using micro-focused synchrotron radiation at BL22XU SPring-8. We measured U L3 and Pu L3 XAS spectra of the particulate and found that the spectra coincide withthose of UO and PuO, respectively.