Fission Product Diffusion in SiC
EMSL Project ID
48306
Abstract
Containment of fission products (FP) within the TRISO fuel particle is critical to the success of the very high temperature reactor (VHTR). In these particles, the SiC layer provides both structural support and serves as the primary diffusion barrier for FPs at temperatures up to 1300ºC during operation. Over sixty years of experience developing and testing this fuel has yet to identify the mechanism by which several key fission products (silver, strontium, europium, and palladium) escape the fuel particle both during operation and in accident simulations. We have developed a novel diffusion couple design that utilizes a structure similar to the TRISO particle in a flat thin film methodology to study fission product diffusion under both thermal and radiation enhanced environments. As part of this study, we propose using EMSL’s time of flight secondary ion mass spectrometer (ToF-SIMS) to provide high-resolution high sensitivity depth profiling to calculate diffusion coefficients as well as EMSL’s Nano-SIMS to map the diffusion profiles in cross-section to identify the mechanisms that allow for fission product diffusion.
Project Details
Project type
Limited Scope
Start Date
2014-06-02
End Date
2014-07-18
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Dwaraknath S., and G. Was. 2016. "The Diffusion of Cesium, Strontium, and Europium in Silicon Carbide." Journal of Nuclear Materials 476. doi:10.1016/j.jnucmat.2016.04.034