Lead Investigator: Kathryn A. Higley (Lead, Oregon State University)
Additional Investigators: Steve Reese, Steve Kustka, Jillian Newmyer, Irene Marry (Oregon State University)

Project Objectives:

Objective 1: Document uptake from soil of uranium, progeny, and other co-located contaminants and their distribution within native (including medicinal and biocrust) and other plant species, from mine impacted sites.  This effort would include continued participation in IAEA CRP K41022 “Transfer of Radionuclides in Arid and Semi-Arid Environments for Radiological Environmental Impact Assessment.” The purpose of the IAEA effort is to standardize the analysis methodology and help expand the dataset on radionuclide uptake in plants (with focus on foodstuffs) in arid and semi-arid environments (most recent participation April 2024). There is a critical lack of data from arid and semi-arid regions (Semioshkina, N., & Voigt, G., 2021). Data generated as part of this collaborative effort can be used to supplement food chain pathway models used in arid and semi-arid regions of the USA as well as other regions around the world.  Emphasis is in plants with medicinal and cultural significance to tribal entities.

Objective 2: Document and analyze specific characteristics of select low energy beta emitters, such as dose coefficients, transfer factors, environmental behavior, and regulatory standards, which drive restrictive remediation standards.  Radionuclides include tritium, carbon-14, iodine-129 and potentially chlorine-36 and selenium-79.

Objective 3: Develop risk communication products for site-specific topics as requested.

Significance/Impact:
EM manages many sites with complex issues related to large-scale contamination in surface soils as well as groundwater plumes.  Contaminants include hazardous chemicals and elevated levels of radionuclides. Long-term control and reduction of bioavailability of these constituents is paramount. Stakeholder confidence in DOE EM’s mission hinges on EM employing scientifically defensible, transparent, inclusive, and efficient environmental remedies during site cleanup.  This can be achieved through employing best practices and current guidance, undertaking an ongoing evaluation of the effectiveness of remediation strategies, investigating and adapting emerging science, and communicating results to a wide range of stakeholders, including the public. Low-level waste (LLW) disposal sites also can benefit, which have been constructed and operated at several facilities, including Idaho National Laboratory, Los Alamos National Laboratory, Oak Ridge Reservation, Savannah River Site, Hanford Site, Moab, and Nevada National Security Site (National Academies, 2017).

Public Benefits:

Stakeholder confidence in DOE EM’s site cleanup efforts is based on EM applying scientifically defensible, transparent, inclusive, and efficient environmental remedies. Addressing scientific data gaps in transfer, uptake, and exposure pathways builds trust through sound science, public communication, and engagement.

References: (* indicates CRESP publication)

*Gomez-Fernandez, M., Higley, K., Tokuhiro, A., Welter, K., Wong, W., & Yang, H. (2020). Status of research and development of learning-based approaches in nuclear science and engineering: A review. Nuclear Engineering and Design, 359.

*Greenberg, M., Burger, J., Lowrie, K., & Higley, K. (2022). Kathryn Higley-Build trust through repeated engagement as an honest expert. Risk Analysis: An Official Publication of the Society for Risk Analysis, 42(11), 2500–2503.

*Hargraves, J. T. (2023). Advancements in Phytoremediation, Dosimetry, and Environmental Radiological Protection: Integrating Endemic Plants, Anatomically Accurate Phantoms, and Real-world Data for Improved Assessments. PhD dissertation, Oregon State University.

National Academies of Sciences, Engineering, and Medicine; Division on Earth and Life Studies; Nuclear and Radiation Studies Board; Planning Committee on Low-Level Radioactive Waste Management and Disposition. (2017). Low-Level Radioactive Waste Management and Disposition: A Workshop [Report]. Washington, DC: National Academies Press.

Semioshkina, N., & Voigt, G. (2021). Soil-plant transfer of radionuclides in arid environments. Journal of Environmental Radioactivity, 237, 106692.

Tilley, D., and T. Pickett. 2016. Plant Guide for Curlycup Gumweed (Grindelia squarrosa). USDA-Natural Resources Conservation Service, Aberdeen Plant Materials Center. Aberdeen, ID.

Wolf, M., and B. Evancho. 2016. Plant Guide for desert globemallow (Sphaeralcea ambigua A. Gray). USDA-Natural Resources Conservation Service, Tucson Plant Materials Center. Tucson, AZ.