Development of structural materials is historically a long and costly process, particularly for nuclear energy applications due to the long proof testing period to validate the performance of the material in the hostile irradiation environment. Utilization of recently developed materials science tools including computational thermodynamics and multiscale radiation damage computational models in conjunction with rapid science-guided experimental validation (nonirradiation and irradiation environments) may offer the potential for a transformational reduction in the time period to develop and qualify structural materials for advanced nuclear energy systems. Several examples of rapid development of high-performance structural materials will be given, with a focus on austenitic and ferritic/martensitic steels (less than two years from project initiation to commercial production of multi-ton prototypic heats). In many cases, the key for development of improved mechanical properties and superior radiation stability is the presence of a uniform high-density dispersion of highly stable nanoscale particles. This research was sponsored in part by the Office of Fusion Energy Sciences, U.S. Department of Energy under contract DE-AC05-00OR22725 with UT-Battelle, LLC.