|About this Abstract
||Materials Science & Technology 2020
||Thermodynamics of Materials in Extreme Environments
||Effect of Physically Determined Coordination-numbers for Modeling Molten Salt Fuels Using the Modified Quasi-chemical Model (MQM)
||Matthew Christian, Juliano Pinto, Theodore Besmann, Timothy Lynch, Wilson Chiu, Nancy Birkner, Kyle Brinkman
|On-Site Speaker (Planned)
Accurately modeling the thermochemical properties of fuel-coolant in molten salt reactors (MSRs) is critical to simulating conditions under operating and accident scenarios. The modified quasi-chemical model (MQM) is frequently used to represent the molten salt’s thermochemical state as it accounts for short-range ordering that arises from strong ionic interactions via atomic coordination numbers. The values for each atomic species are typically approximated from representative crystalline phases and thus may not be reflective of the molten state. Therefore, the short-range ordering imposed by the coordination numbers may not accurately yield Gibbs energies for the liquid and result in incorrect phase relations for molten salt mixtures. In this presentation, we will show how using coordination numbers, predicted by density-functional theory (DFT) and confirmed with experiment, influences modeled phase diagrams generated using MQM for the melt.