About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Radial Examination of Xenon Fission Gas Bubbles in As-Irradiated and Post-LOCA Tested High-Burnup UO2 Fuel using S/TEM-EDS |
| Author(s) |
Lauryn Reyes, Chad M. Parish, Casey S. McKinney, Jason M. Harp, Nathan A. Capps, Brian D. Wirth |
| On-Site Speaker (Planned) |
Lauryn Reyes |
| Abstract Scope |
High-burnup fuel, above 60 GWd/tU, experiences significant microstructural changes associated with subgrain formation and the enhanced production of xenon fission gas bubbles (FGBs). As the nuclear industry extends the burnup limit above 62 GWd/tU, high-fidelity nanoscale characterization will improve knowledge of the fuel microstructure evolution. Samples from two fuel rods commercially irradiated in the North Anna Units 1 and 2 pressurized water reactors reached an average sample burnup of 69 and 77 GWd/tU, respectively, and were observed in the as-irradiated condition and after a simulated loss-of-coolant accident test. This work focuses on quantifying Xe FGB density and pressure along the fuel radius in both test conditions. Scanning/transmission electron microscopy (S/TEM) with energy-dispersive X-ray spectroscopy (EDS) techniques identified xenon FGBs in all radial locations sampled, and a preliminary technique was applied to quantify inter- and intragranular FGBs. Additionally, FGB pressure has been estimated by combining analysis from the S/TEM-EDS data and the Yang and Wirth equation of state. At the fuel periphery, the highest number of Xe bubbles and smallest areas were observed, and the overall number density decreased while the area increased with radial location moving inward. Beginning near the mid-radius (central restructured region), a slight increase in number density and area reduction was observed. Additional analysis is ongoing to identify inter- and intragranular bubbles and obtain a radial distribution of Xe FGB pressure measurements for all sample conditions. This data provides an opportunity to validate computational modeling predictions and improve understanding of fuel performance at high-burnup. |
| Proceedings Inclusion? |
Undecided |