Fiber Optic Scintillator System for Detection of Beta Emitters in Groundwater

70307 Many DOE sites have the need to monitor radionuclide contamination in surface water, groundwater, soils, and the vadose zone. In many cases, a real-time and/or remote monitoring capability is desired. Existing site characterization procedures typically involve the collection and shipment of samples to an off-site laboratory, which leads to costly delays in site remediation as well as to added hazards to personnel. This project will develop a scintillating fiber optic based sensor system, specifically for the detection of beta-emitting radionuclides in groundwater. These sensors will allow selection and preconcentration of the analyte in close proximity to a scintillator detector incorporated as a cladding material on the optical fiber. The configuration would be easily adapted to real-time, remote monitoring scenarios. Phase I will determine the selectivity and detection limits of these sensors for technetium-99. Appropriate plastic scintillator materials will be selected, enrichment polymers will be synthesized and evaluated for analyte selectivity and preconcentration, and the detection limits and selectivity will be determined. The sensing of additional analytes such as strontium-90 and/or tritium will be explored in Phase II. Commercial Applications and Other Benefits as described by the awardee: The fiber optic sensor configurations should be applicable to the preparation of many kinds of sensors. Potential applications for radiation sensors based on this concept include quality control in food irradiation and medical sterilization, as well as in pinpoint dosimetry for newly emerging cancer radiation therapies such as stereotactic radiosurgery and conformal (three-dimensional) therapies.