Abstract
For safety management of fuel debris retrieval in Fukushima Reactor, it is essential to figure out fuel debris dissolution and denaturation mechanisms in advance. Being submerged and cooled in sea water over a decade, interfacial dissolution and denaturation occurred persistently between fuel debris surface and cooling sea water. In this study, experiments of simulated fuel debris dissolution into various solution conditions were carried out, to investigate Uranium dissolution thermodynamic and kinetic behavior under various factors, together with dissolution mechanism difference and comparation between static batch and microfluidic dissolution of uranium.
In this experiment, dissolution experiments of simulated fuel debris (U0.7,Zr0.3)O2 pellets and UO2 pellets in various solution conditions were carried out through batch and microfluidic approach, using novel microfluidic device for micro scale dissolution. Dissolved uranium concentration was monitored by ICP-MS measurement, and surface conditions before and after dissolution were characterized by Raman, SEM and XRD.
Through the experiment, uranium dissolubility in various conditions and kinetics behavior were evaluated, and different mechanisms between bulk scale and microfluidics were speculated.
