In-Situ Transmission Electron Microscopy Study of the Evolution of Extended Defects in Oxide Nuclear Fuels

Conference · Tue Aug 01 00:00:00 EDT 2023

DOI:https://doi.org/10.1093/micmic/ozad067.803· OSTI ID:2309752

Bawane, Kaustubh Krishna ^[1]; He, Lingfeng ^[2]; Kombaiah, Boopathy ^[1]; Mann, J. Matthew ^[3]; Shao, Lin ^[4]; Khafizov, Marat ^[5]; Hurley, David H  ^[1]

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1. Idaho National Laboratory
2. North Carolina State University
3. Air Force Research Laboratory
4. Texas A&M University
5. Ohio State University

In-situ transmission electron microscopy (TEM) with simulated extreme environments is an effective tool for understanding and tracking microstructural changes down to the atomic scale. The objective of this research is to study the effect of temperature on the evolution of extended defects in ThO2 and UO2. Here, we present in-situ TEM isochronal thermal annealing experiments using a micro-electro-mechanical-system (MEMS)-based heating holder. ThO2 and UO2 single crystal specimens were grown inside an inert silver ampoule using hydrothermal synthesis. Both samples were irradiated using 2 MeV protons at 600oC up to 0.1 dpa at Texas A&M University’s Accelerator Laboratory. Fig. 1a shows a weak-beam dark field TEM image of ThO2 after irradiation, indicating the presence of faulted 1/3 <111> type dislocation loops. This presentation will discuss the effect of annealing temperature (600oC, 800oC, 1000oC, 1100oC, etc.) on dislocation loop density, size and distribution, loop nature (interstitial/vacancies) and Burgers vector, as well as the formation of voids in both ThO2 and UO2. This work will also discuss the interaction between defects during annealing. The in-situ TEM annealing cycle is shown in Fig 1b. This research significantly improves the understanding of defect behavior in oxide nuclear fuels with temperature and will aid computational modeling efforts. This work was supported as part of the Center for Thermal Energy Transport under Irradiation (TETI) Energy Frontier Research Center, funded by the U.S. Department of Energy Office of Science.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: 70
• DOE Contract Number: DE-AC07-05ID14517
• OSTI ID: 2309752
• Report Number(s): INL/CON-23-72079-Rev000
• Resource Relation: Journal Volume: 29; Journal Issue: Supplement_1; Conference: Microscopy and Microanalysis 2023, Minneapolis, 07/23/2023 - 07/27/2023
• Country of Publication: United States
• Language: English

Related Subjects

36 - MATERIALS SCIENCE
75 - CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
In-situ TEM
Thorium dioxide
Uranium dioxide
Nuclear fuels
Irradiation
Dislocations
Voids