MOX fuel, a mixture of weapon-grade plutonium and natural or depleted uranium, may be used to deplete a portion of the world's surplus of weapon-grade plutonium. A number of reactors currently operate in Europe with one-third MOX cores, and others are scheduled to begin using MOX fuels in both Europe and Japan in the near future. While Russia has laboratory-scale MOX fabrication facilities, the technology remains under study. No fuels containing plutonium are used in the U.S. The 25 presentations in this book give an impressive overview of MOX technology. The following issues are covered: an up to date report on the disposition of ex-weapons Pu in Russia; an analysis of safety features of MOX fuel configurations of different reactor concepts and their operating and control measures; an exchange of information on the status of MOX utilisation in existing power plants, the fabrication technology of various MOX fuels and their behaviour in practice; a discussion of the typical national approaches by Russia and the western countries to the utilisation of Pu as MOX fuel; an introduction to new ideas, enhancing the disposition option of MOX fuel exploitation and destruction in existing and future advanced reactor systems; and the identification of common research areas where defined tasks can be initiated in cooperative partnership.