High temperature dilatometry of simulated oxide nuclear fuel

10th International School-Conference on Materials for Extreme Environment: Development, Production and Application

Tenishev, A.V.^1 ; Baranov, V.G.^1 ; Kuzmin, R.S.^1 ; Pokrovskiy, S.A.^1

National Research Nuclear University MEPhI, Moscow Engineering Physics Institute, 31 Kashirskoe highway, Moscow

115409, Russia^1

关键词: Complex compositions;    Eutectic melting;    High temperature;    High temperature samples;    Initial composition;    Neutron absorbers;    Nuclear fuel behavior;    Sharp transition;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/130/1/012032/pdf
DOI  :  10.1088/1757-899X/130/1/012032

来源: IOP

【 摘 要 】

High temperature dilatometry of model systems based on uranium dioxide with additives of burnable neutron absorbers both as Gd2O3and as AlGdO3, and fission products simulators (FPS) was performed. It shown that in some cases instead of high temperature samples shrinkage there is a sharp transition to the expansion, which is associated with an increase of the samples volume due to the formation of liquid phases. The beginning of a complex composition eutectic melting starts at temperatures from 1950 to 2250 °C in the uranium dioxide samples containing significant amounts of Al, Gd, and FPS. Thus, in the analysis of oxide nuclear fuel behavior at high temperatures should be considered that the formation of liquid phases is possible at a temperature of 1000 °C lower than a melting point of pure stoichiometric uranium dioxide if its initial composition became more complex.