Dissertation defense: Characterizing Property and Microstructure of Ceramic Nuclear Materials with Laser-based Microscopy

Committee

• Marat Khafizov, PhD, chair (NE)
• Tunc Aldemir, PhD (NE)
• Lei Cao, PhD (NE)
• David Hurley, PhD, (Idaho National Lab)

Abstract

Ceramic nuclear materials are crucial for the structural integrity and healthy functioning of a nuclear reactor. Especially for nuclear fuels, they need to withstand extremely high temperature, high irradiation dose and drastic structural transformation. Many mechanisms contribute to the material degradation, including defect accumulation, pellet-cladding interaction and thermal shocks. Characterizing the properties and microstructure is not only important to improve fuel efficiency, but is also helpful to enhance the tolerance and stability in the rough environment.

There are special requirements with respect to the measurement of nuclear materials, thus many techniques, though widely accepted in some other areas, are excluded. Since nuclear materials are oftentimes radioactive, non-contact measurement with the help of optics or acoustics are desirable to minimize the exposure as well as radioactive wastes. In addition, the property in an irradiated sample is usually inhomogeneous and the sample is usually small and irregular in size due to the limits of in-pile experiment. The techniques should have good spatial resolution down to micrometers and should be able to resolve anisotropic properties.

Laser-based microscopy is a perfect candidate for the characterization of nuclear materials with all the above merits. Here in this study results of several measurement are presented to show its potential.