The thermal diffusivity of simulated DUPIC fuel for irradiation test

Abstract

The thermal diffusivity of simulated DUPIC fuel with an equivalent burnup of 35,000 MWd/tU (3.73 at.%), which was to be tested for irradiation at the HANARO research reactor, was measured using the laser flash method in a temperature range from room temperature to 1623 K. The density of the simulated DUPIC fuel used in the measurement of thermal diffusivity was 10.16 g/cm3 (94.2% of theoretical density) at room temperature, and the diameter and thickness were 10 mm and 1 mm, respectively. The thermal diffusivity decreased from 0.0205 cm2/s at room temperature to 0.0060 cm2/s at 1623 K. The thermal diffusivity of simulated DUPIC fuel was lower than that of UO2 by 36.8% at 300K and by 12.7% at 1623 K. The difference in thermal diffusivity between the simulated DUPIC fuel and UO2 was large at room temperature, and decreased as the temperature increased.