Materials issues for generation IV systems : status open questions and challenges ; [proceedings of the NATO Advanced Study Institute on Materials Issues for Generation IV Systems : Status Open Questions and Challenges Cargèse Corsica France 24 September 6 October 2007] Global warming shortage of low cost oil resources and the increasing demand for energy are currently controlling the worlds economic expansion while often opposing desires for sustainable and peaceful development. In this context atomic energy satisfactorily fulfills the criteria of low carbon gas production and high overall yield. However in the absence of industrial fast breeders the use of nuclear fuel is not optimal and the production of high activity waste materials is at a maximum. These are the principal reasons for the development of a new fourth generation of nuclear reactors m