Ceramic Materials for Nuclear Energy Research and Applications: Poster Session
Sponsored by: TMS Extraction and Processing Division, TMS Structural Materials Division, TMS Light Metals Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Energy Committee, TMS: Nuclear Materials Committee
Program Organizers: Xian-Ming Bai, Virginia Polytechnic Institute and State University; Yongfeng Zhang, University of Wisconsin; Larry Aagesen, Idaho National Laboratory; Vincenzo Rondinella, Jrc-Ec
Wednesday 5:30 PM
March 17, 2021
Room: RM 51
Location: TMS2021 Virtual
Session Chair: Yongfeng Zhang, University of Wisconsin - Madison
A Model of Grain Boundary Energy Anisotropy in Uranium Dioxide Nuclear Fuel: Dallin Fisher; Evan Hansen1; Yongfeng Zhang2; Sean Masengale2; Axel Seoane3; Timothy Harbison1; 1Brighan Young University-Idaho; 2University of Wisconsin-Madison; 3Virginia Tech
Modeling grain boundaries (GB) is vital for predicting nuclear materials performance due to the strong influence of GBs on properties of materials. While GB energy anisotropy is largely understood for fcc and bcc metals, little is understood about the GB energy anisotropy of ceramic oxides, such as UO2, characterized by the fluorite crystal structure and ionic/covalent chemical bonding. In this molecular dynamics study, energies of 239 geometrically unique UO2 GBs were obtained from multiple empirical potentials in LAMMPS. Resulting GB energies show UO2 anisotropy with significant similarities, as well as significant differences when compared with fcc metals. An existing model for GB energy anisotropy in fcc metals was modified to provide a model of UO2 anisotropy that may be extensible to other fluorite ceramic oxides.
Development of Hydrothermal Corrosion Barrier Coatings for High-density Nuclear Fuels: John Lacy1; Hwasung Yeom1; Kyle Quillin1; Kathryn Metzger2; Edward Lahoda2; Kumar Sridharan1; 1University of Wisconsin - Madison; 2Westinghouse Electric Company
Non-oxide uranium fuels such as U3Si2 and UN are being considered for use in accident tolerant cladding because of their high fuel density and superior thermal conductivity. However, it is reported that these fuels have a higher reaction rate with water when the fuel cladding is breached. The high-density fuels are prone to mechanical break-down due to hydride formation during the corrosion reaction. To address this limitation, tests to determine the efficacy of coating pellets with a hydrothermal barrier coating to minimize the degradation of the fuel pellets are being carried out. Several coating options have been investigated including oxidation-resistant glass coatings, ceramic coatings, and metallic coatings. The coatings have been applied to surrogate substrates using methods including dip coating, PVD, and CVD methods. Testing and evaluation of these corrosion barrier coatings will be discussed.
Hydrothermal Corrosion Study of Additive Manufactured SiC Fibers: Arunkumar Seshadri1; Akshay Dave1; Bren Phillips1; Koroush Shirvan1; Shay Harrison2; Joseph Pegna2; 1Massachusetts Institute of Technology; 2Free Form Fibers
SiC/SiC fiber composites are pursued as fuel cladding materials to improve the accident tolerance of light water nuclear reactors (LWR). With the advent of advanced additive manufacturing of ceramic Laser-Induced Chemical Vapor Deposition (LCVD) developed by Free Form Fiber, high purity fibers are developed with the required stoichiometric and dimensional precision. The ability of these fibers to be used in practical applications requires the knowledge of its corrosion performance in extreme environment of a LWR. In the present work, hydrothermal corrosion of commercially available carbon-rich Hi-Nicalon fibers is compared to the stoichiometric and silicon-rich fibers manufactured using LCVD. Autoclave testing was carried out at 310 °C and 14 MPa. Relative measurements based on the hydrothermal corrosion experiments reveal that LCVD fibers show good potential in terms of corrosion resistance compared to commercial fibers. The results also indicate that impact of stoichiometry is likely dominant compared to a particular manufacturing technique.