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Sensitive Instrumentation for Measuring Radionuclides has Revolutionized Radioanalytical Laboratories

Research at Oak Ridge National Laboratory has revolutionized commercial analytical methodology for alpha-emitting radionuclides. This advance in methodology is now embodied in an instrument for detecting radioactive elements commercialized in the 1980s by ORDELA, Inc. of Oak Ridge, Tennessee. More broadly, standard liquid-scintillation instrumentation industry-wide now takes advantage of the same principles first discovered and published by the ORNL researchers. Marketed under the name of PERALS, this instrument, an alpha liquid-scintillation spectrometer, allows facile, yet extremely sensitive measurements of alpha-emitting nuclides such as uranium-238, plutonium-239, and polonium-210. Analyses for these and other alpha emitters are carried out daily on environmental samples, in bio-assays, and in research. Previously, analytical procedures for these radionuclides were subject to interferences and difficult sample preparations. Results suffered from irreproducibility and large uncertainty. The PERALS spectrometer detects light flashes emitted by an extractive scintillator. This is an organic fluid containing selective chemical extractants for radionuclides combined with compounds that emit light flashes upon excitation by radioactivity. The ORNL innovation grew out of the discovery that the light flashes could be sorted electronically as either alpha or beta/gamma events, according to their unique pulse shapes. A prototype instrument based on this principle was developed at ORNL and received an IR-100 Award in 1981. Full commercialization of the technology has been achieved, and hundreds of the units are now in use worldwide.


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Provided by Oak Ridge National Laboratory's Chemical Sciences Division
Rev:   October 20, 2005