Oxygen chemical diffusion in fast neutron reactor fuel UPuAmO

Vauchy, R.; 堀井 雄太; 廣岡 瞬; 赤司 雅俊; 砂押 剛雄*; 中道 晋哉; 齋藤 浩介

Proceedings of 34th Nuclear Energy for New Europe (NENE2025) , p.232 - 238, 2026/01

The oxygen chemical diffusion of fast neutron reactor MOX UPuAmO was investigated by thermogravimetric analysis between 1773 and 1923 K, using an innovative experimental procedure. At a given temperature, the oxygen chemical diffusion coefficients were shown to decrease when the Oxygen/Metal ratio decreases (in hypo-stoichiometry). The variations of the oxygen chemical diffusion coefficients as a function of temperature and oxygen partial pressure (hence oxygen stoichiometry) were paralleled to a defect chemistry model.