This publication examines the many aspects of the increased use of high burnup uranium oxide (UOX) and mixed oxide (MOX) fuel, and its potential impact on spent fuel management as well as on the whole nuclear industry. It discusses reactor types, with emphasis on light water reactor (LWR) and heavy water reactor (HWR) technology, considers the current state of UOX and MOX worldwide, provides information on the various fuel and cladding types and spent fuel management components, and elaborates on the characteristics of spent fuel related to higher burnup UOX and MOX fuels, followed by a detailed analysis. The publication also identifies areas for future research and development.