Alexandra Doherty

Graduate Research Assistant

Research Description

Generation IV nuclear reactors such as the molten chloride fast reactor (MCFR) and thermal energy storing concentrated solar plants (CSP) are promising candidates for providing clean, accessible, and affordable energy amidst the global energy crisis. However, the corrosive properties of molten chloride salts present a major challenge for the utilization of commercial steel alloys as structural materials. Stainless steel (SS) 316H is a primary contender for use as a structural material in MCFRs as well as fluoride salt-cooled high-temperature reactors (FHR). Additively manufactured (AM) SS 316H via laser powder bed fusion (LPBF) and solution annealed 316H are currently of interest as structural materials due to their ability to form complex designs that are unattainable using conventional manufacturing methods, and unique microstructures that exhibit different corrosion mechanisms in nuclear reactor environments. To understand the performance of conventional, AM, and solution annealed SS 316H, it is important to subject samples to (1) corrosion, (2) corrosion + irradiation, and (3) corrosion + stress, to perform a multimodal characterization. NCSU’s PULSTAR Reactor is used for sample exposure to neutron and gamma irradiation. Imaging methodologies include a scanning electron microscope using electron backscatter diffraction (SEM-EBSD) and with energy dispersive X-ray spectroscopy (SEM-EDS), and a transmission electron microscope (TEM).

Background

Lexi completed her undergraduate studies at the University of Cincinnati (UC), earning a Bachelor of Science in Chemical Engineering, minoring in Materials Engineering, while concurrently completing a Master’s in Business Administration. She has industry experience in materials testing and failure analysis spanning metals and polymers at Tesla, and processing ceramics such as zirconium and alumina silicates at Continental Mineral Processing Corp. At UC, Lexi was involved in a design project outlining a process to recycle spent nuclear fuel to produce mixed oxide fuel to limit proliferation and performed literature research on utilizing carbon nanotubes synthesized at UC’s Nanoworld Lab for gamma radiation shielding. In her free time, Lexi enjoys hiking, rock climbing, snowboarding, Cincinnati Bearcats sports, and hanging out with her Australian Shepherd.

Education