Uranium determination on-line using remote fiber fluorimetry

Remote Fiber Fluorimetry (RFF) is being developed at Savannah River Laboratory for the on-line determination of uranium in plant process streams. A prototype system suitable for plant use has been designed and is being built. RFF has four major components: a laser, an optical fiber, an optrode, and a detector. Essentially, an optical fiber carries laser radiation from a laser to a process sampling point. An optrode (the optical analog of an electrode) couples the laser light into a sample solution. Fluorescence from the sample is collected by the optrode and goes back through the same fiber to a detector. Using an RFF system, the analysis can be made both simply and safely. The laser and detector are placed at a convenient remote location, such as the control room. Optical fibers run from the laser to either the sample aisle or process tanks. Multiplexing makes it possible to analyze several different sampling positions with one laser and detector. The incentives for demonstrating this technology include reduced analysis time and decreased sample load for the laboratory. Since RFF is a remote on-line technique, sample handling is avoided. Analysis time is five minutes (versus the four-hour minimum needed now), and the control laboratory has a decreased sample load. Finally, RFF could easily be incorporated into a large-scale process control system.