This book discusses the design, manufacture and behaviour of nuclear fuel in PWRs (pressurized water reactors) and FRs (fast reactors). It reflects the unrivalled knowledge of the French Agency for Nuclear Power (CEA) and other specialised companies in the field (Framatome, a reactor constructor, EDF, a reactor operator, Cogema, a fuel manufacturer and reprocessor). Their combined expertise covers all aspects of the industry. The book concentrates on normal operating conditions, including operating incidents related to fuels. Safety considerations and some safety analysis principles are examined, from fuel design to reaction stages. Conditions resulting from accidents are not discussed as these are usually related to the overall functioning of power plants. Begining with a review of the various types of fuel, the book moves on to introduce concepts of fuel design and future prospects. It gives a comprehensive description of : fuel production, fuel cladding and fuel assembly , fuel behaviour inside the reactor , absorber elements , spent fuel management. Finally, the appendices to this major reference feature calculations, equations and examination of irradiated fuels.