The role of nuclear energy in a sustainable development context has multiple facets, a significant number of which relate to the nuclear fuel cycle. This report provides a description of the developments and trends in the nuclear fuel cycle that may improve the competitiveness and sustainability of nuclear generating systems over the medium and long term. It also presents criteria and indicators for future nuclear energy systems. Prepared by experts from the nuclear industry, government agencies and research organisations, this report will be of interest to those involved in nuclear energy policy and decision making.