Abstract
This study investigates the temperature dependent thermal conductivity of multiphase ceramic composites for simulated inert matrix nuclear fuel. Fine grained composites were made of CeO2-MgAl2O 4-CeMgAl11O19 or 3Y-TZP-Al2O 3-MgAl2O4-LaPO4. CeO2 and 3Y-TZP are used as UO2 surrogates due to their similar structures and low thermal conductivities. Laser flash analysis from room temperature to 1273 K (1000 °C) was used to determine the temperature dependent thermal conductivity. A computational approach using Object Oriented Finite Element Analysis Version 2 (OOF2) was employed to simulate the composite thermal conductivity based on the microstructure. Observed discrepancies between experimental and simulated thermal conductivities at low temperature may be due to Kapitza resistance; however, there is less than 3% deviation between models and experiments above 673 K (400 °C) for both compositions. When the surrogate phase was replaced with UO2 in the computational model for the four-phase composite, a 12-16% increase in thermal conductivity resulted compared to single phase UO2, in the range of 673-1273 K (400-1000 °C). This computational approach may be potentially viable for the high-throughput evaluation of composite systems and the strategic selection of inert phases without extensive sample fabrication during the initial development stages of composite nuclear fuel design.
| Original language | English |
|---|---|
| Pages (from-to) | 69-76 |
| Number of pages | 8 |
| Journal | Journal of Nuclear Materials |
| Volume | 454 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - Aug 19 2014 |
| Externally published | Yes |
Funding
This research is supported by the U.S. Department of Energy funding under grant DE-NE0000711 . Some of the materials were developed under an NSF DMR-0606063 grant. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. The authors acknowledge the use of the UC Irvine Laboratory for Electron and X-Ray instrumentation (LEXI). A U.S. Department of Education Graduate Assistance in Areas of National Need (GAANN) Fellowship provided additional graduate student support for JPA.