Dr. Stephen Taller, an alumnus of the U-M Department of Nuclear Engineering & Radiological Sciences (NERS), has been selected as the recipient of a ProQuest Distinguished Dissertation Honorable Mention from the Rackham Graduate School for his dissertation, “The Role of Damage Rate on Cavity Nucleation With Co-Injected Helium in Dual Ion Irradiated T91 Steel.” The award recognizes highly accomplished graduate students who have produced exceptional dissertations of outstanding scholarly quality in any field of study.
Taller is currently an Alvin M. Weinberg Fellow at Oak Ridge National Laboratory (ORNL). He received his B.S. from Purdue University in 2013, his M.S. from NERS in 2015, and his Ph.D. from NERS in 2020. After receiving his Ph.D., he worked as a postdoc with NERS Prof. Gary Was until joining ORNL.
“Stephen Taller’s thesis provides a major leap forward in the global effort to develop ion irradiation as a means of emulating irradiation effects in reactors,” said Prof. Was.
Taller’s dissertation focused on how accelerated damage rate experiments in the laboratory can capture the relevant processes that occur in structural materials in a nuclear reactor. He used multiple ion beams simultaneously bombarding a target as a source of radiation damage at a rate 1,000× higher than test reactors to isolate the roles of temperature, damage rate, and helium co-generation rate in the nucleation of cavities that lead to the life-limiting degradation mode of irradiation-induced swelling. His work also involved developing a physical model to speculate where helium resides in the microstructure of ferritic-martensitic steel after irradiation.
“The technology and state of the art for studying radiation damage are constantly evolving,” said Dr. Taller. “My work will hopefully make a significant contribution to the field of radiation materials science and in the deployment of advanced reactors.”