NSUF 12-393: Investigation of Silver Grain Boundary Diffusion in Irradiated Silicon Carbide
The objective of this work is to understand the effect of irradiation on Ag transport in polycrystalline SiC by measuring diffusion in an irradiated SiC substrate with a subsequent comparison of previously investigated Ag transport observed in un-irradiated SiC substrates. The work will utilize the ATR NSUF partner facility capabilities of the Michigan Ion Beam Laboratory’s National Electrostatics Corporation 400 kV implanter to implant 400 kV Ag+ in irradiated SiC substrates. The SiC substrates used in this work will be irradiated by the Authors at the University of Wisconsin-Madison’s Ion Beam Laboratory’s NEC Pelletron 1.7 MV Tandem Accelerator with 6 MeV C3+ ions prior to Ag+ implantation. Following implantation samples will be thermally annealed and the change in distribution of implanted Ag will be analyzed by secondary ion mass spectroscopy to determine the difference in solubility and diffusion rates in irradiated SiC compared to the un-irradiated condition. The role of specific grain boundaries and irradiation induced defects will be investigated through scanning transmission electron microscopy investigation of the Ag distribution in the diffusion area of the irradiated SiC substrate indicated by SIMS analysis.This work contributes to the understanding of the Ag release phenomena observed in irradiated tristructural isotropic (TRISO) fuel which is proposed for use in the DOE’s Next Generation Nuclear Plant program’s Very High Temperature Gas Reactor concept and to the understanding of the observed variation in reported diffusion coefficients reported in scientific literature. Ag diffusion coefficients in SiC reported from recent experimental studies in un-irradiated SiC substrates presented diffusion coefficients orders of magnitude lower than the reported values obtained from fractional release measurements through irradiated SiC layer. This work addresses the key variable of irradiation effects on Ag transport and will determine if irradiation enhances permeability of Ag through SiC, leading to a more in-depth understanding of Ag release from TRISO fuel.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of this work is to understand the effect of irradiation on Ag transport in polycrystalline SiC by measuring diffusion in an irradiated SiC substrate with a subsequent comparison of previously investigated Ag transport observed in un-irradiated SiC substrates. The work will utilize the ATR NSUF partner facility capabilities of the Michigan Ion Beam Laboratory’s National Electrostatics Corporation 400 kV implanter to implant 400 kV Ag+ in irradiated SiC substrates. The SiC substrates used in this work will be irradiated by the Authors at the University of Wisconsin-Madison’s Ion Beam Laboratory’s NEC Pelletron 1.7 MV Tandem Accelerator with 6 MeV C3+ ions prior to Ag+ implantation. Following implantation samples will be thermally annealed and the change in distribution of implanted Ag will be analyzed by secondary ion mass spectroscopy to determine the difference in solubility and diffusion rates in irradiated SiC compared to the un-irradiated condition. The role of specific grain boundaries and irradiation induced defects will be investigated through scanning transmission electron microscopy investigation of the Ag distribution in the diffusion area of the irradiated SiC substrate indicated by SIMS analysis.This work contributes to the understanding of the Ag release phenomena observed in irradiated tristructural isotropic (TRISO) fuel which is proposed for use in the DOE’s Next Generation Nuclear Plant program’s Very High Temperature Gas Reactor concept and to the understanding of the observed variation in reported diffusion coefficients reported in scientific literature. Ag diffusion coefficients in SiC reported from recent experimental studies in un-irradiated SiC substrates presented diffusion coefficients orders of magnitude lower than the reported values obtained from fractional release measurements through irradiated SiC layer. This work addresses the key variable of irradiation effects on Ag transport and will determine if irradiation enhances permeability of Ag through SiC, leading to a more in-depth understanding of Ag release from TRISO fuel. |
| Award Announced Date | 2013-12-20T00:00:00 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Kumar Sridharan, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Izabela Szlufarska |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 393 |