There is worldwide interest to promote the use of nuclear power and close the nuclear fuel cycle. The long-term successful use of nuclear power is critically dependent upon adequate and safe processing and disposal of spent nuclear fuels. The current procedure for accounting of nuclear materials within an existing reprocessing plant is a periodic annual plant closure, which is a significant fraction of the operating budget. The one year time lag between inventories does not meet the need of identifying immediate or timely detection of diverted materials. There is urgent need for methods to provide on-line monitoring and control of the radiochemical processes that are being developed under the DOE-NE Fuel Cycle Research and Development program. The instrumentation must be robust, maintenance free, and able to withstand harsh radioactive environments. The use of state-of-the-art process monitoring equipment for use on-line, and in-process will enable nuclear fuel reprocessing processes to run more efficiently and without plant shutdown during periodic plant inventory. The outcome of this program will be an integrated Raman/UV-vis-NIR process monitoring system capable of real-time measurements of multiple locations within a nuclear fuel reprocessing cycle. The process probe will detect key analytes in the PUREX process. This will improve the operation of the reprocessing plant and also provide accountability of fissile materials. The Phase I work will include the design and prototype development of a flow through cell with integrated Raman probe and UV-vis-NIR absorption probe that can be easily coupled to the DOEs Pacific Northwest National Laboratory PNNL) test setup for process monitoring. A multi-input spectrograph will be designed and prototyped to simultaneously detect multiple probes. The prototype probe and flow cell will be evaluated at PNNL using chemical simulants mimicking DOE nuclear fuel cycle reprocessing solutions. The technology developed can be applied for fuel reprocessing operations and other solvent extraction processes. Other industry applications are in the process monitoring of oil refineries, chemical and metallurgical manufacturing processes and pharmaceutical production, where Raman and absorption probes are already widely used but not as an integrated system.