Professor Brian Wirth for the Richard K. Osborn Lecture - "Predicting Degradation in Fission and Fusion Environments"

Friday, April 01, 2016
4:00 PM to 5:00 PM
2355 Bonisteel Blvd., 1906 Cooley Bldg., Ann Arbor, MI 48109

The Nuclear Engineering & Radiological Sciences welcomes Professor Brian Wirth for the Richard K. Osborn Lecture and Webcast.  The title of Professor Wirth's talk is"Predicting Degradation in Fission and Fusion Environments".

Abstract

The plasma facing components, first wall and blanket systems of future tokamak-based fusion power plants arguably represent the single greatest materials engineering challenge of all time. Indeed, the United States National Academy of Engineering has recently ranked the quest for fusion as one of the top grand challenges for engineering in the 21st Century. These challenges are even more pronounced by the lack of experimental testing facilities that replicate the extreme operating environment involving simultaneous high heat and particle fluxes, large time varying stresses, corrosive chemical environments, and large fluxes of 14-MeV peaked fusion neutrons. Fortunately, recent innovations in computational modeling techniques, increasingly powerful high performance and massively parallel computing platforms, and improved analytical experimental characterization tools provide the means to develop self-consistent, experimentally validated models of materials performance and degradation in the fusion energy environment. This presentation will describe the challenges associated with modeling the performance of nuclear fuels, structural materials, and plasma facing component in the nuclear fission or fusion environment, the opportunities to utilize high performance computing within a multiscale materials modeling hierarchical approach, and then focus on example of recent progress to predict materials degradation. In particular, we will describe results modeling to describe the defect cluster evolution observed from in-situ ion irradiation studies of thin film materials in the transmission electron microscope of molybdenum and ferritic/martensitic steels, and then turn to describing the dramatic surface evolution of tungsten exposed to low-energy He and H plasmas. Modeling results will be presented to identify the mechanisms of tungsten surface morphology changes when exposed to 100 eV He plasma conditions as a function of temperature and initial tungsten microstructure, and demonstrate the ability to integrate results from atomistic-scale modeling to continuum level predictions.