| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Characterization and Modeling of Nuclear Fuels: Microstructure, Thermo-physical Properties
|
| Presentation Title |
Correlating Atomic Scale Microstructure with Mechanical Properties in Low-density Pyrocarbon Used in TRISO Particle Fuel Buffer Layer |
| Author(s) |
Yongfeng Zhang, Claire Griesbach, Ramathasan Thevamaran, Kumar Sridharan, Tyler J. Gerczak, Wen Jiang, Karim Ahmed |
| On-Site Speaker (Planned) |
Yongfeng Zhang |
| Abstract Scope |
TRISO fuel is a leading fuel design for advanced high temperature reactors. A critical component to its irradiation performance is the buffer layer consisting of low-density porous pyrocarbon, whose actual matrix density and atomic-scale structure are unknown. Guided by 3D experimental characterization, atomic-scale models were constructed using molecular dynamics simulations for low-density pyrocarbon. The constructed pyrocarbon contained nano-sized, graphite-like crystallites of different orientations, connected by disordered regions with atoms bonded differently than graphite. The atomic-scale structure was quantified by fractions of sp2 and sp3 bonded atoms. A new descriptor named atomic orientation was introduced for graphite-like atoms, and its spatial correlation and 3D distribution were used to determine the crystallite size and the degree of anisotropy. The atomic-scale structure was further correlated with the elastic moduli also from molecular dynamics. This work is a part of a larger multiscale effort for quantifying and correlating buffer layer microstructure with mechanical properties. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Modeling and Simulation, Nuclear Materials, Mechanical Properties |