Recycling the actinides, a beneficial contribution to the overall environmental sustainability of nuclear energy systems.
Résumé
Actinides recycling still remains a controversial issue for many countries which do not yet have make a definite and clear choice about the back-end of their nuclear fuel cycles. In particular, recycling is often questioned about its effective impact on the overall nuclear energy sustainability. In order to address this key issue, we developed a Life Cycle Assessment (LCA) tool, referred to as NELCAS, based on the current French nuclear energy system. Thanks to the Nuclear Safety and Transparency annual reports, detailed quantitative data were available for each of the fuel cycle plants. The whole fuel cycle from ore-mining to geological repository was considered as well as data for construction, deconstruction of any plants as well as the contribution of the transport. All the matter and energy fluxes were considered and normalised versus the electric production. Key environmental indicators as well as potential impact indicators were hence assessed and validated with comparison with the few existing LCA results.NELCAS was also used to derive other fuel cycles by correcting when necessary the relevant flux of matter and energy all along the fuel cycle. A particular focus was put on the once-through cycle with no recycling at all and the effect of the introduction of fast neutron reactors which allow actinides multi-recycling. For the very first time, it hence allows a direct and robust assessment of the effect of recycling operations on the most widely used environmental indicators. Among others, it clearly demonstrates the beneficial effect of Pu and U recycling on most of the indicators. This improvement increases with any recycling increase and is directly related to the very high contribution of the front-end operations in the overall environmental footprint. Most of the indicators are very significantly decreased with the implementation of long-term recycling strategies. This presentation will therefore detail how actinides recycling help to improve the environmental footprint and sustainability of the overall nuclear energy.