Award Date

May 2016

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Health Physics and Diagnostic Sciences

First Committee Member

Ralf Sudowe

Second Committee Member

Francis Cucinotta

Third Committee Member

Gary Cerefice

Fourth Committee Member

Brenda Buck

Number of Pages

73

Abstract

Dust Samples were collected from three different location at the Nellis Dunes Recreation Area, each being of a different soil type. These samples were sieved to different particles sizes and then analyzed using a high-purity germanium gamma well detector. The isotopes found in each sample were: Pb-214, Th-231, Pb-212, Cs-137, and K-40. The activities for these isotopes ranged from: 8.36 * 10-7 µCi/g to 3.11 * 10 -6 μCi/g, 2.53 * 10-7 µCi/g to 9.98 * 10-7 µCi/g, 2.17 * 10-7 µCi/g to 2.51 * 10-7 µCi/g, 7.41 * 10-8 µCi/g to 4.22 * 10-7 µCi/g, and 7.38 * 10-6 µCi/g to 3.74 * 10-5 µCi/g receptivity. Based on this study and supported by several others, there does appear to be a correlation between not only particle size and radionuclide concentration, but also soil type and radionuclide concentration. Moreover, a lung dose model was created and conservative estimates were performed to calculate a dose for breathing a year’s worth of dust at the Nellis Dunes Recreation Area. The highest possible dose was calculated out to be .0684 rem, which is lower than the NRC’s annual limit to the general public. Finally, the levels of the Cs-137 were compared to several other locations around the world and the quantities were found to be consistent with global fallout. This means that the proximity that the NDRA has to the Nevada National Security Site does have any noticeable effect on it.

Keywords

Health Physics; Isotopes; Radionuclide

Disciplines

Medicine and Health Sciences

Language

English


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