Woodruff School of Mechanical Engineering
Nuclear & Radiological Engineering and Medical Physics Programs
Understanding nuclear materials through advanced characterization and PIE
Dr. Fidelma Di Lemma
Idaho National Laboratory
Thursday, September 5, 2019 at 11:00:00 AM
Boggs Building, Room 3-47
This presentation will focus on microscopy techniques (mainly SEM and EPMA) to understand fuel behavior from fabrication to irradiation, including safety test. Understanding grain structure and texture in materials science is of paramount importance, as these factors influence most mechanical properties. For nuclear materials texture and grain structure can influence material properties relevant to reactor performance, such as swelling, yield stress, fracture toughness etc. Moreover, such data are of primary importance to develop and validate physics-based models for nuclear fuels based on microstructure evolution during irradiation (e.g. MARMOT). The talk will focus on the challenges of working with metallic fuel and irradiated samples by SEM/EBSD, and current improvement in this application. Facilities and techniques available at INL-Material Fuel Complex will be presented to encourage possible collaboration. Further this presentation will cover the ongoing experimental effort in the frame of separate effect tests (SET) for safety studies of Sodium Fast Reactor (SFR) metallic fuel. As studies are still necessary to optimize and extend operational and safety limits through reduction of uncertainties in transient fuel behaviors and fuel failure thresholds for specific SFRs. These studies at providing data for the validation of M&S tools, which are essential for supporting licensing and utilization. The proposed SET studies for source term determination focus on small-scale experiments investigating fission product behavior in metallic fuel and aimed at deconvoluting the effect of different variables on mechanisms important to radionuclide release.
Dr. Fidelma Di Lemma is currently working as a Metallography Scientist at Idaho National Laboratory (INL), performing advanced characterization on cladding materials and fuel, and supporting various DOE programmatic effort from USHPRR to AFC. At INL she also fulfills the role of instrument scientist for NSUF with a focus on EBSD characterization and EPMA analyses, supporting the user facility. She has significant experience with the characterization of nuclear fuel and materials (SEM/EDX/EBSD, XRD, Raman spectroscopy, ICP-MS), including post irradiation examination with her main field of expertise being fission product behavior and separate effect experiments. In the past she worked at the Japan Atomic Energy Agency gaining expertise on the behavior of fission products during severe accidents and interaction of cladding, fuel and structural materials during accidents, and at the European Commission where she performed source term characterization from Radiological Dispersion Events. Her personal research include study of simulated HBS structure and separate effect studies to understand the behavior of metallic fuel under transient. She obtained a Ph.D. from TU Delft in 2015 and Master and Bachelor Diploma with honors in Nuclear Engineering from the University of Rome La Sapienza in 2011, 2009. She is also actively involved in promoting nuclear science and technologies trough professional societies and obtained IYNC early career award in 2016.
Refreshments will be served.