Characterization of Interfacial Reactivity, Geochemistry, Transport, and Biodegradation for Nuclear Waste Forms
EMSL Project ID
50713
Abstract
This research is part of an international collaborative effort to address the wide diversity of environmental roles that radionuclides can play during their lifetime within corroding nuclear wastes and their transport through a geologic repository setting where complex, concomitant and interdependent processes, such as surface complexation, biogeochemistry, mineral nucleation and growth, redox reactions, colloid formation, microbial activity, and transport through micro- and nanostructured layers control the reactivity of the wasteform and the chemical fate and transport of radioactive contaminants under terrestrial and subsurface conditions. By better understanding these processes and their intercorrelation, uncertainties in the understanding of these processes will be reduced thus improving the confidence and accuracy of the source term for radionuclide fate and transport models. The United States, Japan, France, the United Kingdom, and Belgium each have programs to vitrify nuclear waste materials prior to disposal. In glasses, radioactive cations become intrinsically incorporated into the structure, resulting in a highly durable product, with borosilicate glasses exhibiting particularly excellent aqueous durability. The current US models for the corrosion of waste glasses were developed for a mixed-waste repository system, however, and are extremely conservative. Further, Japanese researchers have recently begun to explore bulk vitrification as an option for waste soil related to the destruction of the Fukushima Daiichi power station. Near surface disposal of these wastes and others may be subjected to biological processes that further increase the uncertainty in the process. An Energy Frontiers Research Center (EFRC) for Performance and Design of Nuclear Waste Forms and Containers, WastePD, has recently been initiated by the Office of Science to perform innovative studies of waste form performance, develop fundamental understanding of the environmental degradation mechanisms, and design new and improved waste form and container materials. Together with the capabilities of EMSL, this scientific team will achieve a truly valuable outcome: the refinement of materials corrosion models using the knowledge bases of all materials classes, thus revising existing long-term glass corrosion models to reflect more accurately the extraordinary durability of vitrified nuclear wastes and opening a significant opportunity to better utilize the storage volume of any repository.
Project Details
Start Date
2019-02-27
End Date
2019-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
McCarroll I.E., P. Bagot, A. Devaraj, D.E. Perea, and J. Cairney. 2020. "New frontiers in atom probe tomography: a review of research enabled by cryo and/or vacuum transfer systems." Materials Today Advances 7. PNNL-SA-153475. doi:10.1016/j.mtadv.2020.100090
Zachman M., N. De Jonge, R. Fischer, K.L. Jungjohann, and D.E. Perea. 2019. "Cryogenic Specimens for Nanoscale Characterization of Solid-Liquid Interfaces." MRS Bulletin 44, no. 12:949-955. PNNL-SA-148424. doi:10.1557/mrs.2019.289