Doctoral Dissertations

Date of Award

12-2016

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Nuclear Engineering

Major Professor

Howard L. Hall

Committee Members

Lawrence H. Heilbronn, George K. Schweitzer, Joseph R. Steinbach IV

Abstract

With the threats facing the world today, there is an ever-increasing need for training the the fields of radiochemistry and nuclear forensics. Training and research in these fields requires reference materials that accurately represent materials that could potentially be encountered. Unfortunately, many of the historical samples of debris from nuclear weapons tests remains classified. Because of this, there is a need for realistic surrogates. This research focuses on the development of surrogates for the bulk and particulate nuclear melt glass that is expected to be found in an urban setting after a nuclear event.

A mathematical model for the creation of surrogate melt glass precursor matrices was developed. The model was used to determine the elemental composition of melt glass precursor for the Trinity site, New York City, and Houston, Texas. The precursor matrices were used to generated surrogate bulk nuclear melt glass. While this has been previously done for the Trinity site, this study marks the first time that surrogate bulk nuclear melt glass has been produced for urban scenarios. A thermal spray coater was used to demonstrate that the precursor matrices can be used to generate surrogate particulate melt glass.

Both the bulk and particulate surrogate melt glasses were analyzed using scanning electron microscopy (SEM). Chemical differences on the surface of the samples was determined using backscatter electron analysis (BSE). Energy dispersive spectroscopy (EDS) was used to determine the elemental composition of features observed via SEM. A more complete elemental analysis of the surrogates was conducted using inductively coupled plasma time-of-flight mass spectrometry (ICP-TOF-MS). Crystalline structure was determined using powder X-ray diffraction (P-XRD). Expected fission and activation products cause for each of the matrices were modeled. Notional uranium-fueled and plutonium-fueled improvised nuclear devices (IND) were examined in the radiological models.

Using the developed mathematical models were in conjunction with the synthesis techniques outline, it is apparent that these methods will be able to provide for and meet the current academic, training, and research needs. However, further optimization of the synthesis and analysis processes is needed before large scale production can occur.

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