NSUF 25-5412: Impact of irradiation induced defects on thermal conductivity of zirconia

This project aims to quantify how radiation-induced defects affect thermal conductivity in tetragonal zirconia (t-ZrO2), a key phase in the oxidation layers of zircaloy cladding used in nuclear reactors. 2 MeV proton irradiation will be conducted at the Accelerator Laboratory at Texas A&M University (TAMU) under varying temperatures (20 °C, 300 °C and 600 °C) and doses (0.05 dpa and 0.5 dpa). This approach has previously been applied to ThO2 and UO2 at the same facility, allowing for meaningful comparison of defect behavior across structurally related oxide systems. Irradiated samples will be analyzed using focused ion beam (FIB) and transmission electron microscopy (TEM) to characterize defect structures, particularly dislocation loops. Thermal conductivity will be measured using a thermal conductivity microscope (TCM) supported by a separate project. By comparing loop size and density in t-ZrO2 with prior results from cubic ZrO2, this study will assess phase-dependent damage behavior. Building on prior irradiations of ThO2 and UO2 using the same protocol, this study will allow comparison of defect characteristics in t-ZrO2 across other oxide ceramics. If successful, the work will provide an understanding of how extended defects degrade phonon-mediated thermal transport in t-ZrO2. This will fill a knowledge gap in the current literature, where t-ZrO2, an important phase in the cladding oxidation layers, has not yet been examined using this defect-thermal transport framework. The proposed work will be completed within nine months and is expected to provide results relevant to cladding performance modeling in advanced nuclear systems.

Additional Info

Field Value
Awarded Institution North Carolina State University
DOI 10.46936/NSUF/60015732
Embargo End Date 2027-10-27
Facility Tech Lead Lin Shao, Mukesh Bachhav
Irradiation Facilities Accelerator Laboratory
NSUF Call FY 2025 RTE 2nd Call
PI Sadman Sakib
PIE Facilities Microscopy and Characterization Suite
Project Member Dr. Lingfeng He, Associate Professor - North Carolina State University (https://orcid.org/0000-0003-2763-1462)
Project Member Dr Kaustubh Bawane, Postdoctoral Research Associate - Idaho National Laboratory (https://orcid.org/0000-0002-2291-4466)
Project Member Dr. Zilong Hua, Staff scientist - Idaho National Laboratory (https://orcid.org/0000000229423344)
Project Member Mr Sadman Sakib, Graduate Research Assistant - North Carolina State University (https://orcid.org/0009-0006-0203-1718)
Project Type RTE