[2E17-19] Debris 2

[2E19] Studies on Dissolution Behavior of Uranium from Simulated Nuclear Fuel debris using a Microfluidic Device

*TONGYU XU¹, Naokazu Idota¹, Takehiko Tsukahara¹ (1. Tokyo Tech)

Keywords:Uranium dissolution, Fuel debris, Microfluidics, Dissolution dynamics

To safely manage retrieval of nuclear fuel debris in Fukushima-Daiichi reactor, understanding of fuel debris dissolution and denaturation behavior is crucial. This research aims to clarify dissolution behavior of simulated fuel debris using bulk and microfluidic techniques. Novel microfluidic devices enclosing fuel pellets were designed and made by polydimethylsiloxane (PDMS). Bulk-scale and micro-scale uranium dissolution experiments from different fuel samples were carried out, and effects of various solution were examined. Uranium concentrations were measured by ICP-MS, surface conditions were characterized by Raman, SEM, XRD, and so on. It was found that drastic increase of uranium dissolution rate could be induced by flowing H₂O₂ solution in a microchannel. Results suggest that uranium interfacial reaction kinetics matters in determining dissolution rate.