PNNL

Abstract

The study and development of present and future processes for the treatment/recycling of spent nuclear fuels require many steps, from design in the laboratory through to setting up on an industrial scale. In all of these steps, analysis and instrumentation are key points. For scientific reasons (small-scale studies, control of phenomena, etc.) but also as regards minimizing costs, risks, and waste, such developments are increasingly carried out on milli/microfluidic de-vices. The logic is the same for the chemical analyses associated with their follow-up and interpretation. Due to this, over the last few years opto/microfluidic analysis devices adapted to the monitoring of different processes (dissolu-tion, liquid/liquid extraction, precipitation, etc.) have been increasingly designed and developed. In this work we prove that photonic lab-on-a-chip (PhLoC) technology is fully suitable for all actinides concentration monitoring along the plutonium uranium refining extraction (PUREX) process. Several PhLoC microfluidic platforms were specifically designed and used in different nuclear R&D laboratories, to tackle actinides analysis in multiple oxidation states even in mixtures. The detection limits reached (a few µMol.L-1) are fully compliant with on-line process monitoring whereas a range of analyzable concentrations of three decades can be covered with less than 150 µL of analyte. Finally, this work confirms the possibility and the potential of coupling Raman and UV-Visible spectroscopies at the microfluidic scale, opening the perspective of measuring very complex mixtures.