Suppression of MOX fuel used in LWR swelling caused by development of gas babble resulted from He accumulated during long-term storage

Serizawa, Hiroyuki  ; Kondo, Sosuke*; Hinoki, Tatsuya*

Pieces of CeO (100) thin film were heat treated at 1273 K for 2h. The films were irradiated with 130-keV He ions using 400-keV ion implanter of TIARA. The ion doped film was heat treated at 1773 K for 2 h in air. After the heat treatment, the sample for STEM analysis was prepared for STEM analysis by FIB. It was found that many blisters were formed on the surface of the thin film. The blisters are considered to be formed by gas babble accompanied by the precipitation of He beneath the surface. The lid of the blister is blown away since the sample is ceramics. Many gas babbles are formed in the thin film. The size of the gas bubble falls within the range from 30 to 100 nm in diameter. The shape of the gas bubble is truncated octahedron but clearly different from that of void, which mean that the existence of He in the gas bubble effect on the shape of the gas bubble.