Establishing uranium migration parameters for the Indian Springs Range

For the past 24 years, depleted uranium (DU) kinetic energy penetrators used by the US Air Force have been tested and evaluated to develop targeting system algorithms at a site in the Mojave Desert. This two-fold study focused on reducing uncertainties in the environmental parameters used to model DU migration in arid soils through extensive soil characterization; and evaluated potential horizontal migration of DU through close examination of erosion tracts traversing the target area. Model error reduction was achieved by developing site-specific parameters for DU migration on various impacted soil horizons. Parameters determined in this work included distribution coefficients, soil texture, soil pH, uranium activity concentration, and soil particle density, as well as characterization of motile playa layers subject to sporadic flash flooding events. Using these values in the Residual Radiation (RESRAD) computer code resulted in an individual's first year total dose of 35 mrem under a resident farmer scenario. A sensitivity analysis was performed on several parameters, identifying the soil distribution coefficient (Kd) and density as the most significant to source removal and dose reduction. Data generated from RESRAD provided 238U soil clean up criterion of 200 pCi g-1 for decommissioning based on agricultural land usage requirements, and a limit on the sum of exposures from all model pathways to 25 mrem per year. Observations were made validating DU transport by erosion with activity concentration decreasing exponentially with distance. Recommendations are made to help mitigate the DU surface transport processes.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Health Physics and Diagnostic Sciences

Grantor dc:publisher

University of Nevada, Las Vegas

Year

2004

Author dc:creator

• Abell, Clinton E

Contributors dc:contributor

• William H. Johnson

Statement dc:rights

• IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English

Identifier

https://oasis.library.unlv.edu/rtds/1680

OAI identifier oai:identifier

oai:oasis.library.unlv.edu:rtds-2679