Development of Multi-Sorbent Barrier Systems for Low-Level Radioactive Waste (LLW) Facilities
Disposal facilities for low-level radioactive waste (LLW) and mixed waste (MW) have leachate containing long-lived radionuclides, such as iodine-129 (129I) and technetium-99 (99Tc). Theses radionuclides exist predominantly in an anionic speciation (e.g., 129I- and 99TcO4-), are highly mobile in the environment, and have a very long half-life (over a million years). A multisorbing barrier (MSB) material is being developed for LLW and MW facilities that can bind anionic radionuclides as well as a variety of other constituents of concern (e.g. cationic species, organic compounds, and mercury) while also maintaining very low hydraulic conductivity. MSB is comprised of a combination of materials that have complementary sorption characteristics, such as sodium bentonite clay (NaB), organoclay (OC), and anion resins (R).