Accelerated development of advanced nuclear ceramics

Traditionally, the design of advanced nuclear materials with high radiation tolerance involves modifying the structure in materials, such as introducing interfaces and grain boundaries or incorporating the secondary phases into materials, like in ODS steel. In the past decade, another way of controlling the chemistry and composition of materials has been proposed, and the high entropy alloy has been proven to have outstanding radiation tolerance. Building on this concept, high entropy ceramics have recently been proposed as a means to develop materials with superior properties.

In this project, the radiation tolerance of high entropy ceramics will be investigated through integrative methods, including multiscale simulation and experimental characterization. The influence of microstructure and composition in high entropy ceramics on the defect evolution behavior will be explored. The purpose of this project is to design novel ceramics with desirable radiation tolerance for extreme applications. 

Applying machine learning approaches to understand material corrosion in molten salts

Design of advanced ceramics to meet all the requirements for nuclear structural applications is challenging, especially in the absence of a thorough understanding of the influence of harsh working environments on materials behavior. For example, in fluoride salt-cooled high-temperature reactor (FHR) environment, one major challenge is the corrosive fluoride salt environment on the structural materials, which may degrade the materials chemical stability and induce safety issues.

In this project, we will focus on the mechanistic understanding of material corrosion in FHR system. A combination of multiscale simulations and machine learning approaches will be employed, which can provide valuable information that would be difficult to gain experimentally. The purpose of this project is to build a kinetics-based model to understand and predict the corrosion behavior of structural materials in molten salts, and to provide strategies for the design of novel structural materials that have long-term stability in molten salts.

Integrated experimental and computational study of complex-structured materials with improved radiation & corrosion resistance

The nuclear reactor environment could be one of the most extreme environments in the world. Materials used in nuclear reactors must endure high temperatures and pressures, intense radiation doses, and chemically aggressive conditions. These extreme conditions can interact with one another, creating even more challenging environments within the reactors.

In this project, the synergetic effects of radiation and corrosion on the microstructural and microchemical evolutions in nuclear materials will be investigated, employing both experiment and simulation efforts. The foci of the experimental efforts will be the characterization of the corrosion and radiation responses of materials to the variable complex nano/microstructures and microchemistry. As a complement and even an extension of experiments, we will develop multiscale models involving both radiation damage and corrosion degradation phenomena. Meanwhile, the developed multiscale model will be further employed to predict the microstructural/microchemical changes in the conditions beyond the experiments. The purpose of this project is to mechanistically understand the coupled effects of complex structured materials in those coupled environments, as well as to improve the materials radiation & corrosion resistance.