The study of the distribution of arsenic, mercury, thorium, protactinium, uranium and neptunium under the ChemChar gasification process using radionuclide tracers

An experimental method to measure the fate and distribution of a variety of radionuclides under the ChemChar gasification process has been developed. The elements studied were arsenic, mercury, thorium, protactinium, uranium and neptunium. Results indicate that the ChemChar gasification system quantitatively retains these elements. In all of the cases except mercury the radiotracer was found to reside on the char matrix with small amounts (<1%) being found downstream in the condensation trap and char filter. Mercury, presumably as vapor, was entrained and distributed in significant amounts (similar to 40%) to the downstream char filter and its pre-filter. A methodology was developed to account for char height differences in quantifying the radiotracer on the char prior and subsequent to gasification. These results demonstrate the efficacy of using relatively short-lived radiotracers to characterize the behavior of hazardous elements during waste treatment via gasification.