November 15, 2019
Journal Article

A review of the behavior of radioiodine in the subsurface at two DOE sites


The 129I isotope has a half-life of nearly 16 million years, creating a potential risk to receptors when 129I is present in groundwater and effective remedies are needed to mitigate its potential risk in the environment. This paper not only provides an in-depth review of various processes and reactions that control the fate and transport of iodine, but also describes how this information can be used for in situ management of iodine. The majority of the iodine fate and transport studies have been conducted at the US Department of Energy (DOE) Hanford and Savannah River sites, where radioisotopes of iodine were inadvertently released into the environment during weapons production. Site-specific remediation technologies are currently being evaluated as part of the DOE cleanup mission. The sites are markedly different in terms of climate (arid vs. sub-tropical), major geochemical parameters (pH ~ 7.5 vs. 4) and mineralogy (carbonate vs. Fe/Al oxide dominated), but they share the same network of processes and reactions that control iodine fate and transport. These include adsorption to minerals and sediments, interactions with organic matter, electron transfer reactions with minerals and microbes, and precipitation. This process-based network serves as basis for regional scale model calculations to predict plume spreading and/or dissipation, design efficient remediation techniques and conduct contamination management activities.

Revised: October 15, 2020 | Published: November 15, 2019


Neeway J.J., D.I. Kaplan, C.E. Bagwell, M.L. Rockhold, J.E. Szecsody, M.J. Truex, and N. Qafoku. 2019. A review of the behavior of radioiodine in the subsurface at two DOE sites. Science of the Total Environment 691. PNNL-SA-138439. doi:10.1016/j.scitotenv.2019.07.146