Accident tolerant fuel concepts

Our recent research in this area has focused on the development of innovative high-entropy alloy thin films (HEATF) and refractory high-entropy alloy thin films (RHEATF) for coating conventional nuclear-grade fuel-cladding materials such as zirconium alloys and austenitic stainless steels. High-entropy alloys have been reported to possess improved radiation tolerance, superior mechanical strength and corrosion resistance. These properties are key to protecting surfaces to mitigate oxidation processes at high temperatures in nuclear-fuel cladding without penalising the efficient operation of the nuclear power plant. Accident tolerant fuel (ATF) concepts using advanced thin films will potentially be used to reduce the probability of catastrophic failures in nuclear reactors during serious accident events.

SEM micrographs of Zircaloy-4™ prior deposition and after the deposition of the HEATF. Bottom image shows a TEM micrograph of the ATF system HEATF deposited on Zircaloy-4™, Credit: M.A. Tunes, V.M. Vishnyakov and S.E. Donnelly

Researchers in the EMMA research centre have achieved success in producing these thin films by plasma vapour deposition (PVD) onto the Zircaloy-4™ zirconium alloy. A refractory version of the HEATF on the new commercial nuclear alloy Zirlo™ is expected to resist exposure at very high temperatures (above 2000°C). The irradiation resistance of the HEATF and the RHEATF have been tested at the unique Microscopes and Ion Accelerators for Materials Investigations (MIAMI) facility and compared to the performance of conventional thin film coatings such as titanium nitride.

Energy Filtered TEM images taken after in situ 134 keV Xe irradiation at 573 K up to 12 dpa in both HEATF (top) and TiN (bottom). Recent results indicates on superior stability of the HEATF under irradiation. Energy Filtered TEM images taken after in situ 134 keV Xe irradiation at 573 K up to 12 dpa in both HEATF (top) and TiN (bottom). Recent results indicates on superior stability of the HEATF under irradiation, Credit: M.A. Tunes, V.M. Vishnyakov and S.E. Donnelly

International Collaborations and Partnerships 

University of São Paulo (Brazil)

Texas A&M University (United States)

Oak Ridge National Laboratory (United States)

Santa Catarina State University (Brazil)

São Paulo State Technology College (Brazil)