STP 955 resulted from a major international forum for the exchange and discussion of both the fundamental and technological aspects of behavior change in materials exposed to radiation environments. 66 papers comprise this book whose contents have been categorized into seven distinct technical areas: radiation-induced defects and their diffusion; neutron-induced swelling; charge particle-induced swelling; theory of swelling and irradiation creep; microstructural evolution; solute segregation and phase stability; and effects of implantation.