Date of Award
Master of Science
Department of Engineering Physics
John W. McClory, PhD.
A method is developed for rapid detection and analysis of actinides and correlated materials in nuclear fallout debris using principal component analysis on quantified micro x-ray fluorescence intensity values. This method is then applied to address goals of nuclear forensics. The first implementation is a collaborative effort with the National Institute of Standards and Technology and the Federal Bureau of Investigation Laboratory to produce a standard reference material that is a surrogate for glassy nuclear fallout debris in a modern urban environment. This reference material will enable researchers in the development and validation of nuclear forensics methods. A method for determining material homogeneity is developed and demonstrated. A preliminary minimum sample size for the surrogate fallout SRM is calculated to be 0.607 g based on an infinite thickness depth of 2.242 mm. It is also shown that, for an adequately simple model, the surrogate fallout SRM is indistinguishable from real fallout. The second implementation is a quantitative analysis of element-actinide correlation in historical nuclear test fallout debris, which will contribute further to the body of knowledge surrounding the formation of nuclear fallout. Eleven historical fallout samples are used. A method for determining the elemental composition descriptors that best account for the variance in these samples is developed. A trend in the composition of media surrounding areas of significant activity, based on correlation of autoradiography images, is confirmed for micro x-ray fluorescence.
DTIC Accession Number
Castro, Sarah T., "Nuclear Forensics Applications of Principal Component Analysis on Micro X-ray Fluorescence Images" (2016). Theses and Dissertations. 334.