[2C16-21] Decommissioning Technology for Fukushima 2

[2C21] Development of ultramicro analysis technology for fuel debris analysis

(8)Nanostructure analysis of fuel debris by TEM

*Kenta Yoshida¹, Yusuke Shimada¹, Yufeng Du¹, Hotaka Miyata¹, Toru Kitagaki², Atsushi Ohno Ikeda², Hideo Watanabe³, Kenji Konashi¹, Yasuyoshi Nagai¹ (1. Tohoku Univ., 2. JAEA, 3. Kyushu Univ.)

Keywords:Simulated fuel debris, (Zr,U)SiO4, TEM

During a severe accident, the fuel debris containing stainless steels and concrete components are formed by contacting of molten fuels with structural materials of the reactor. We report the nanostructural analysis of the Fe-containing precipitates and FIB-sliced microstructures around the phase boundary in the fuel debris, which was firstly achieved by a spherical aberration-corrected transmission electron microscopy (AC-TEM). These results are not only important to evaluate the physical properties of fuel debris, but also to estimate the temperature and oxygen atmosphere during the formation process of fuel debris during the severe accident.