Novel Neutron Detector for High Rate Imaging Applications

65608 To treat hazardous wastes and low-level mixed wastes, the Department of Energy (DOE) is using or evaluating several thermal and non-thermal technologies. However, these technologies have the potential to generate highly toxic gaseous emissions of polychlorinated dioxins/furans, which, under recently promulgated regulations, must be limited to very low levels. The current regulatory method for the offgas sampling and analysis of these compounds requires a relatively bulky sampling train consisting of a stack probe, transfer lines, a filter to catch particulates, and an organic resin trap to capture vapor phase dioxins. The materials from the sampling train are then sent to a specialized laboratory for analysis. This project will develop a faster, more streamlined method to monitor and control dioxin/furan emissions by combining supercritical fluid extraction with solid phase microextraction. Such a combination can efficiently extract dioxins/furans in a sample matrix, remove interferences (through appropriate choice of supercritical fluid extraction conditions and up-take solvent), and concentrate the analyte without an evaporative concentration step. Phase I will develop and demonstrate the supercritical fluid extraction/solid phase microextraction procedure that will extract dioxin/furan from the offgas particulate and present the extracted dioxins/furan to an analyzer/detector in a relatively purified and concentrated form. Commercial Applications and Other Benefits: A field-deployable dioxin monitor would permit more frequent regulatory monitoring of combustion sources for highly toxic dioxins/furans. Dioxin/furan monitors should find use in steel plants, cement kilns, and thermal and non-thermal treatment of hazardous and mixed waste.