Speaker
Description
Understanding the environmental distribution of radioiodine isotopes produced during pyrochemical reprocessing is critical for evaluating the ecological footprint of next-generation nuclear fuel-cycle facilities. We analyze ¹²⁹I/¹²⁷I ratios in sagebrush (Artemisia tridentata) and in collected air masses across the Idaho National Laboratory (INL) desert complex using Accelerator Mass Spectrometry (AMS) to assess a detection framework for potential emissions from INL’s Fuel Conditioning Facility (FCF). Comparisons between vegetation- and atmosphere-derived isotopic ratios establish a basis for distinguishing localized source terms from background signals.
Environmental ¹²⁹I/¹²⁷I ratios associated with historic operations at INL’s Idaho Chemical Processing Plant (ICPP) are evaluated in conjunction with National Oceanic and Atmospheric Administration (NOAA) historical wind data. A spatial transport framework is developed to describe wind-driven redistribution of soil-bound iodine as a function of downwind and crosswind distance from the primary source term. Application of a general linear regression model yields exponential decay constants corresponding to a downwind e-folding distance of 14 km and a crosswind half-width e-folding distance of 13 km. Analysis of sampled air masses indicates that particulate, soil-bound iodine contributes minimally to atmospheric iodine isotope ratios, suggesting that observed signals primarily reflect gaseous or direct atmospheric source terms.