As demand for electricity continues to increase worldwide, the worlds nuclear power generating capacity will continue to grow. Nuclear power is the most environmentally benign way of producing electricity on a large scale. The long-term successful use of nuclear power, however, is critically dependent upon adequate and safe processing and disposal of spent nuclear fuels. A very important feature of nuclear energy is that spent fuels can be reprocessed to recover fissile and fertile materials that can then be used as fresh fuel for nuclear power plants. The DOE-NE Fuel Cycle Research and Development (FCR&D) is currently developing nuclear material reprocessing technologies. In a typical nuclear fuel reprocessing system, centrifugal contactors are used as liquid-liquid extraction devices where two immiscible liquids are mixed at high speeds using a rotor, which creates a fine dispersion of droplets of organic phase in an aqueous phase that contains the analyte. Understanding the extraction efficiency at these contactors through modeling and simulation is important in the development of reprocessing technologies and the optimization of current technologies such as the PUREX process. The outcome of this program will be a liquid-liquid microfluidic flow cell chip with embedded Raman sensors for the analysis of extracted analytes. This device will be useful in the optimization of new fuel reprocessing schemes as well as existing reprocessing processes by providing a microfluidic modeling platform to optimize extraction parameters. The Phase I work will include the design and prototype development of a liquid-liquid extraction microfluidic flow cell with integrated fiber optically coupled spectroscopic probes. The efficient production of organic phase micro droplets in an aqueous phase and integration of Raman sensors for determining the extraction parameters of the extraction process will be developed. Commercial applications are in the process monitoring of oil refineries, chemical and pharmaceutical production, where liquid-liquid separation process are widely used. The use of microfluidic devices for optimizing liquid-liquid separation processes will be attractive because of the small amount of sample volume needed which can minimize materials cost.
