The purpose of this research was to understand the behavior of high strength, corrosion resistant steels as cladding and structural components for advanced nuclear reactor cores under intense radiation fields. The elevated temperatures and radiation of the advanced nuclear reactor core will cause unknown changes in material properties over time for many steel alloys. These changes need to be fully characterized to ensure safe production of nuclear energy. An analytical transmission electron microscope (AEM) capable of detecting very small changes in the structure and chemistry of steel upon exposure to radiation was used, which allowed for new insights to be obtained about the inherent material properties of steel. The project found radiation-induced structural damage and chemistry changes at the atomic level. These changes can lead to increases in strength, but at higher levels could also cause the steel to become brittle and fragile. This study successfully determined which atomic structures are potentially high risk for changes in local chemistry and therefore should be avoided in manufacturing to promote long service life, safe steels for the next generation of nuclear reactors. Ultimately, the detailed understanding obtained in this study will help the development of safe and efficient advanced nuclear reactors in the future. This project served as a mechanism for bridging two different institutions, and nations, with similar nuclear energy goals. The project served as an international collaboration and professional development venture with far-reaching benefits to science and the safety of the general public.