Date: Thursday, Jun 5th
Presenter: Steve Zinkle, University of Tennessee and Oak Ridge National Laboratory
A variety of fission and fusion energy concepts are under consideration for meeting future energy needs. After a brief review of current and proposed fission and fusion energy systems, the crucial role of high performance materials on possible future pathways for fission and fusion energy systems will be discussed. Key materials science aspects associated with operation in these extreme temperature, mechanical stress and radiation environments will be summarized. A particularly important aspect is the requirement for structural materials to exhibit resistance to radiation-induced degradation to neutron bombardment. The general mechanisms of radiation-induced property degradation in materials will be outlined. Several strategies can be utilized to develop structural materials with simultaneous high radiation resistance, high strength, good toughness and corrosion resistance, and moderate fabrication cost. There are three general approaches for designing radiation resistance: Nanoscale precipitates or interfaces to produce high point defect sink strength (e.g., oxide dispersion strengthened (ODS) and next-generation ferritic/martensitic steels with high particle densities); purposeful utilization of materials at temperatures where vacancies are immobile (e.g., SiC/SiC ceramic composites); and utilization of radiation-resilient matrix phases (e.g., ferritic instead of austenitic steel matrix). High-performance steels designed using computational thermodynamics are demonstrating promising capability to produce a high density of highly stable nanoscale precipitates that could serve as efficient point defect recombination centers during irradiation, and also provide good mechanical properties over a wide range of temperatures.
Steve Zinkle is a Governors Chair in the Nuclear Engineering Department with a joint appointment in the Materials Science and Engineering Department at the University of Tennessee, Knoxville. Prior to October, 2013, he was the Chief Scientist of the Nuclear Science and Engineering Directorate and a Corporate Fellow at Oak Ridge National Laboratory (ORNL). He previously served as the director of the ORNL Materials Science and Technology Division from 2006 - 2010, and in a variety of research scientist and program management roles since he joined ORNL in 1985 as a Eugene Wigner fellow. Much of his research has utilized materials science to explore fundamental physical phenomena that are important for advanced nuclear energy applications. His research interests include deformation and fracture mechanisms in structural materials and investigation of radiation effects in ceramics, fuel systems, and metallic alloys for fusion and fission energy systems. He received his PhD in Nuclear Engineering and an MS in Materials Science from the University of Wisconsin-Madison in 1985. He has written over 240 peer-reviewed publications, is a recipient of the 2006 U.S. Department of Energy E.O. Lawrence Award, and is a fellow of 7 professional societies including American Physical Society, The Minerals, Metals and Materials Society (TMS), the American Nuclear Society, Materials Research Society and ASM International. He is a member of the National Academy of Engineering.