Titanium Nanoparticles Effect on Oxygen Diffusion in Sodium Oxidation

Abstract

As one of generation IV type reactors, the sodium-cooled fast reactor (SFR) has been extensively researched since 1950s. The SFR utilizes liquid sodium as a coolant for its superior thermal properties as well as excellent compatibility with other structural materials. However, due to high chemical reactivity of sodium with oxygen and water, fire or explosion can occur in case of leakage. Therefore, dispersing titanium nanoparticles has been proposed and experimentally validated by researchers to control the reactivity. The main goal of this research is to study the effect of titanium nanoparticles during sodium oxidation. As sodium oxidation is a complex reaction with simultaneous occurrence of surface chemical reaction and oxygen diffusion, titanium nanoparticles effect on the reaction is explored. In this study, the sodium oxidation characteristic in presence of titanium nanoparticles is fundamentally investigated at initial temperature of 350 oC. Previous researches have focused on nanoparticles effect in decrease of peak temperature. However, unlike other studies, this research focuses on titanium nanoparticles effect during heat decay of the reaction. Temperature decay trend during sodium oxidation is closely investigated, and pure sodium and sodium with dispersed nanoparticles cases are compared. Significant thermal oscillation is observed during oxidation of sodium with dispersed nanoparticles (40-60nm), and this phenomenon is analyzed.