Deconvoluting Reactor Environmental Effects with Nanometer Resolution
Principle Member of Technical Staff
Sandia National Laboratories, PO Box 5800 Albuquerque NM, USA 87185
The environment in the current generation of nuclear reactors is a complex combination of radiation (displacement and transmutation products), thermal, mechanical (creep and fatigue) stressors making it difficult to predict materials performance. The materials design and selection becomes even more difficult under the higher temperature, displacement damage, and corrosive conditions desired for most next generation nuclear systems. To inform, refine, and validate the ever-advancing predictive models, we have developed and are continuing to advance a unique set of tools to explore the overlapping extreme environments with adequate spatial and temporal resolutions to study the combinatorial effects. The in situ ion irradiation transmission electron microscope (I3TEM) currently combines a TEM, two accelerators, and two lasers. This Nuclear Science User Facility (NSUF) and Center for Integrated Nanotechnology (CINT) leveraged facility has an eclectic combination of capabilities permitting real time observation with 0.25 nm spatial resolution and enhanced temporal resolution during sequential or concurrent irradiation and implantation with one, two, or three ion beams simultaneously. In addition, we have over ten in-situ TEM stages that permit either ion or laser irradiation experiments to be performed at a range of temperatures, liquid or gas environments, and mechanical loading conditions. To highlight some of these capabilities, recent results in a variety of systems ranging from nanoparticles through spent fuel will be presented. This ensemble of results will demonstrate how the complex nuclear reactor environment can be parsed with careful consideration into a set of very controlled environments.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.
Khalid Hattar is a Principle Member of the Technical Staff in the Department of Radiation-Solids Interaction at Sandia National Laboratories. He received a B.S. in Chemical Engineering from University of California, Santa Barbara in 2003, and a Ph.D. in Materials Science and Engineering from University of Illinois, Urbana-Champaign in 2009. He specializes in determining the property-microstructure relationships for a variety of structural, electrical, and optical materials through in situ TEM in various extreme environments, as well as tailoring local properties of materials through ion beam modification.