Abstract: Structural materials for use in nuclear reactors are subject to extreme environments such as neutron irradiation, high temperature, various forms of mechanical loading, and corrosive media. Understanding the microstructure-property relationship of materials is of critical importance to the life extension of existing reactors and the development of advanced reactors.

In this talk, I will present the progress the Nuclear Materials group has made over the years in collaboration with the APS, in bringing cutting-edge X-ray diffraction, microscopy, and imaging techniques to nuclear structural materials research. Several case studies will be presented, which shows that high-energy X-rays are a powerful probe for multiscale phenomena in neutron-irradiated alloys.