[en] Energy demand continues to grow in spite of drastic efforts, especially in OECD countries for efficiency and energy savings. At the same time, the concept of sustainable development is calling for the alleviating and/or mitigating of environmental impacts. A limited number of options, that are technically mature and economically competitive, can substitute fossil fuel burning for electricity generation. Nuclear power is one of the electricity generating options that can contribute to an environmentally friendly development. The paper investigates the potential role of nuclear power in global energy supply up to 2050 and analyses the opportunities and challenges, for governments and nuclear industries, of a broad nuclear power deployment in response to environmental concerns. It concludes that, in the long term, increasing substantially the share of nuclear power in electricity generation is feasible and would contribute significantly to enhancing the sustainability of energy supply systems world-wide. (author)