Nuclear Energy Is Part of the Solution for a Sustainable Carbon Free Future

While present energy consumption is extensively dominated by fossil fuels, fast growing energy needs worldwide together with concerns about energy security and climate change spur a regain of interest for nuclear energy as leading carbon free energy source, as well as for technologies of carbon reduction for major fossil energy sources. This not only prompts an active development of advanced light water reactors (LWR, Generation III) over the next decades, but also revives research on commercially viable fast-neutron reactors with multiple nuclear fuel recycles that best meet requirements for a sustainable development (Generation IV).

Light water reactors are likely to remain the dominant source of nuclear energy over the 21^st century with steady progress in safety, economic competitiveness and utilization of uranium. Fast neutron reactors will achieve major progress in sustainability as their use of uranium is much more efficient (~80% compared to less than 1% in current LWRs) and they minimize the long term decay heat and radiotoxic inventory of the radioactive waste. Their design and operation will have to make them perform at least at the level of advanced light water reactors in terms of safety and non-proliferation, even though their physics is different and their fuel cycle is closed. D-T Fusion reactors, if commercially viable, may take part in the energy mix  later in the 21^st century, featuring disruptive progress on safety, long lived waste management and non-proliferation owing to the different nature of fuel, physics and radioactive waste.

The progress achieved through these successive generations of nuclear systems should enhance the public acceptance of nuclear energy. As a link between them, the fuel cycle is key to achieve progress in sustainability as it governs the utilization of natural resource, production of nuclear fuel for the next generation and the nature of ultimate waste.

Active frameworks of international cooperation enable sharing the cost and effort to develop future nuclear systems (Generation IV International Forum, IAEA/Inpro, Euratom Sustainable Energy Technology Platform, ITER…) and experimental or prototype facilities are essential to demonstrate advanced technologies and build consensus on international standards that will frame the commercialization of future nuclear power systems worldwide.