In this course, materials principles are taught in the initial lectures; students do not need to have prior understanding of them. The course will cover the metallurgy and phase diagrams of alloy systems important in the design of commercial nuclear power plants. The micro-structural changes that result from reactor exposure (including radiation damage and defect cluster evolution) are discussed in detail. The aim is to create a linkage between changes in the material microstructure and changes in the macroscopic behavior of the material. Also discussed is the corrosion of cladding materials as well as the effects of irradiation on corrosion performance, and the effects of primary and secondary coolant chemistry on corrosion. Both mathematical methods and experimental techniques are emphasized so that theoretical modeling is guided by experimental data. Materials issues in current commercial nuclear reactors and materials issues in future core and plant designs are covered.