1. National Science Foundation Radiation Interaction with Nanostructured Ceramics Jie Lian, Rensselaer Polytechnic Institute, DMR 1151028 Outcome: Researchers at Rensselaer Polytechnic Institute identified that the radiation tolerance of materials at the nano-scale shows a strong size dependence. Impact: The fundamental understanding of radiation-interaction with nanostructured materials provides the insight in designing tolerant materials for controlling and mitigating radiation damage utilized in extreme radiation environments. Explanation: Nanostructured materials are not intrinsically radiation stable and a strong size-dependence in radiation behavior was identified. Particularly, materials at an intermediate size regime show optimized stability against radiation, in which radiation-induced defects can be effectively annealed at surfaces, interfaces and grain Professor Jie Lian, of Rensselaer’s Mechanical, Aerospace & Nuclear Engineering, led the research team in investigating radiation- interaction behavior with nanostructured materials, enabling a science-based design for radiation tolerant materials by nano-scale materials design. boundaries. Materials at smaller size may be intrinsically unstable against radiation due to the pre-existing defects (crystal imperfection) at smaller particles. Size dependence of Radiation Tolerance (courtesy of Jie Lian) Particle Size Radiation Stability Defect annealing Optimized Performance Destabilization

2. National Science Foundation Outcome: Intense Radiation may cause defect accumulation and materials properties degradation/failure, or so called Wigner Disease. Researchers at Rensselaer Polytechnic Institute discovered that few layer graphene has strong self healing capability and can be immune to radiation disease. Impact: Current oxide fuel has very low thermal conductivity, significantly affecting heat transfer efficiency, energy generation and safe operation of nuclear reactor systems. Mechanically-strong and highly thermally-conductive graphene can find use as an additive to strengthen materials and improve heat transfer efficiency. The capability of defect self-healing and immunization to radiation disease enable potential applications of few layer graphene under intense radiation environments including in nuclear fuels. Few Layer Graphene Can be Immune to Radiation Disease Jie Lian, Rensselaer Polytechnic Institute, DMR 1151028 Explanation: Defects induced by radiation can self- recombine at elevated temperature due to enhanced defect mobility. The two-dimensional geometry of graphene also provides large surfaces behaving as sinks for effective defect recovery. At 600 o C, well below reactor operation temperature, few layer graphene maintains its structural integrity without suffering radiation disease. Photo: Robbie Tannenbaum, a high school senior of Half Hollow Hills District, New York, presented his research on graphene synthesis at Summer@Rensselaer in August 2012. He was selected as one of national finalists of prestigious Siemens Competition and Intel Science Talent Search as a result of his work done in Prof. Lian group.