Micro/nano-structural examination and fission product identification in neutron irradiated AGR-1 Triso fuel - 18529
- Fuel Design and Development Department, Idaho National Laboratory, Idaho Falls, ID 83415-6188, USA (United States)
- Materials Science and Engineering Department, Idaho National Laboratory, Idaho Falls, ID 83415-2211, USA (United States)
- Experiment Analysis Department, Idaho National Laboratory, Idaho Falls, ID 83415-6188, USA (United States)
- Science and Technology Division, Los Alamos National Laboratory, Los Alamos, USA (United States)
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA (United States)
Advanced electron microscopic and micro-analysis techniques were developed and applied to study irradiation effects and fission-product behavior in selected low-enriched uranium-oxide/uranium-carbide tri-structural-isotropic (TRISO)-coated particles from fuel compacts in four capsules irradiated to burnups of 11.2 to 19.6% fissions per initial metal atom (FIMA) consisting of Baseline, Variant 1, and Variant 3 fuel types. Trend analysis shows precipitates were mostly random in their distribution along the perimeter of the inner pyrolytic carbon-silicon carbide (IPyC-SiC) interlayer with only weak association with kernel protrusion and buffer fractures. Pd is dominantly found in most precipitates in both intra and intergranular locations. Nano-sized Ag is predominantly found in grain boundaries and triple points with only two findings of Ag inside a SiC grain in two different compacts (Baseline and Variant 3 fueled compacts). Generally, more element combinations exist for precipitates from particles with relatively low Ag retention compared to particles with relatively high Ag-retention irrespective of fuel type. This study shows the presence of Cs in particles from all compacts evaluated. From this work, no single fission product mechanism hypothesis can be reported. The complexity of mechanisms is further highlighted by the multiple variations of elemental combinations found in the more than 700 fission product precipitates examined. It seems that movement of Ag is not assisted by a specific element in all cases. Therefore, it is not necessarily true that a chemical-assisted transport mechanism is dominant. The presence of Ag predominantly on grain boundaries suggests that a grain boundary transport mechanism may be prominent. Studies to determine the effect of neutron damage are recommended for future work. (authors)
- Research Organization:
- American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
- OSTI ID:
- 23032676
- Resource Relation:
- Conference: HTR 2016: International Topical Meeting on High Temperature Reactor Technology, Las Vegas, NV (United States), 6-10 Nov 2016; Other Information: Country of input: France; 33 refs.; available from American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (US)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electron Microscopic Examination of an Irradiated TRISO Coated Particle of AGR-2 Experiment: AGR2-222-RS019
Electron microscopic evaluation and fission product identification of irradiated TRISO coated particles from the AGR-1 experiment: A preliminary Study