Ensuring the safe and efficient operation of nuclear power plants (NPPs)—both existing and next-generation—requires advanced, integrated modeling and simulation capabilities that can address evolving technical, regulatory, and cost-related challenges. In this talk, I will introduce the vision and ongoing efforts of the Crosscutting Research in Operations and Safety of Nuclear Energy Systems (CROSS) group at the University of Tennessee, Knoxville. The presentation will highlight recent and current work on model-data integration using scientific machine learning to support digital engineering initiatives for NPPs. By leveraging expertise in thermal hydraulics, instrumentation and controls, and artificial intelligence, our research aims to improve the performance of safety analysis tools, enable predictive maintenance and intelligent decision support, and accelerate innovation toward a more competitive nuclear power future.