288 Environmental Geoscience (Posters)

Wednesday, 4 November 2015
9:00 AM - 6:30 PM
Exhibit Hall

PREDICTIVE MODELING OF TERRESTRIAL RADIATION EXPOSURE FROM GEOLOGIC MATERIALS

Paper number: 288-5
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey (Moxham 1963; Pitkin, Bates et al. 1964). The purpose of this project is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and previously existing aerial surveys from the National Uranium Resource Evaluation (NURE) Survey. Using these data, geospatial areas that are homogenous in terms of K, U and Th are defined and the gamma ray exposure rate is predicted. The prediction is compared to data collected via detailed aerial survey by our partner National Security Technologies, LLC (NSTec), allowing for the refinement of the technique.

Models have been developed in two study areas in Southern Nevada that include the alluvium on the western shore of Lake Mohave, and Government Wash north of Lake Mead; both of these areas are arid with little soil moisture and vegetation. In general, we determined that by using geologic units to define the geospatial areas of exposed bedrock and ASTER visualizations to break up and define the geospatial areas of alluvium and colluvium, regions of homogenous geochemistry can be defined allowing for the exposure rate to be predicted for each region.

This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy and supported by the Site-Directed Research and Development Program.

References

Moxham, R. (1963). "Natural Radioactivity In Washington County, Maryland." Geophysics 28: 262-272.

Pitkin, J., R. Bates, et al. (1964). "Aeroradioactivity surveys and geologic mapping (Nuclear facility background gamma radiation measured by aerial radiological measurement)." The Natural Radiation Environment: 723-736.

DOE/NV/25946--2551