A Highly Selective and High Efficiency “Smart” Sorbent for Iodine-129

Statement of the problem or situation that is being addressed in your application Radioiodine is produced during neutron-induced fission reaction when 235U atoms are split into lower atomic weight isotopes such as 129I. Some of the water bodies at sites where reactors were fueled by uranium are contaminated with 129I. Currently there is no viable technology that can lower the concentration of 129I to acceptable levels. This is due the fact that most of the commercially available sorbents are not selective to iodine. Further, iodine forms a weak bond with these sorbents, leading to significant desorption. The proposed Phase I program aims to address the challenge of developing a sorbent that has high selectivity for iodine, as well as forms a strong bond with iodine to have irreversible adsorption. General statement of how this problem is being addressed The objective of the Phase I program is to demonstrate the feasibility of a new sorbent that has high specificity for 129I adsorption, particularly in the presence of competing anions. Through innovations in the structure, morphology and surface characteristics of high surface area materials, we propose to develop a sorbent that is robust enough for long-term in situ deployment. Successful laboratory bench scale testing in Phase I will be followed by field studies in Phase II. What is to be done in Phase I? Working in collaboration with a researcher at an academic institution with expertise in radionuclide remediation, and building upon NEI’s core competency in developing nanoparticle-based sorbents, we will synthesize the sorbent, and characterize for particle morphology and composition. The adsorption capacity of the sorbent will be determined under various parameters, such as concentration of competing anions, pH, ionic strength, and organic ligands. Commercial Applications and Other Benefits While the proposed program is focused on developing a sorbent to remove 129I from nuclear fission sites, the technology itself is generic and can be used to remove a wide range of contaminants such as radionuclides, heavy metals, and other inorganic and organic contaminants from wastewater. The global market for sorbents, which includes molecular sieves, activated carbon, alumina, silica gel and clay has the potential to reach $4.3 billion by 2020 at a CAGR of 6.3%. Iodine-129 (129I), along with Technetium-99 and Carbon-14, are among the most prevalent environmental contaminants at radiological waste disposal sites as well as in the groundwater at nuclear material fabrication and processing plants. The proposed program provides a significant public benefit by developing a sorbent that can efficiently remove 129I from the contaminated sites. Other areas where the proposed technology can be used include municipal drinking water treatment, industrial process water treatment, and industrial wastewater treatment. Key Words Sorbent, Radionuclides, Fission, Nuclear, Iodine-129, 129I, Selectivity, Wastewater, Anion