Chemistry Dissertation Defense – Matthew Heaney

About the event

Speaker: Matthew Heaney

Group: Dr. Xiaofeng Guo

Title: Local Structures of Uranium of Relevance to the Current and Future Nuclear Fuel Cycle

Abstract:

The nuclear fuel cycle is a complex system that has great variability in the chemistry, materials science, and physics throughout its entirety. Its long term sustainability, safety, and optimization depend on a fundamental understanding of the materials and chemistry involved. While macroscopic models traditionally rely on the average long range crystallographic order to predict material behavior, the critical thermodynamic, chemical, and phase transitions governing uranium systems are fundamentally driven by the local structural environment. This dissertation investigates the local coordination, short range disorder, and surface behaviors of uranium across three distinct stages of the nuclear fuel cycle – the front end extraction of uranium, mid-stream fuel properties when partially oxidized, and environmental remediation on the back end, by leveraging advance X-ray and neutron characterization techniques. Together these studies demonstrate that local structural insights are essential for engineering macroscopic solutions across the nuclear fuel cycle.