Lead fast reactor sustainability

The electricity production systems, especially those based on nuclear fission, are increasingly facing more tight constraints and are subjected to more deep analyses based on the three aspects of economical sustainability, environmental sustainability and social sustainability. Nuclear Reactors future development has been outlined in the framework of the GIF (Generation IV International Forum), where the Lead Fast Reactor (LFR) is placed among the most promising innovative solutions. Many aspects of LFR offer a huge improvement from different points of view. The non pressurization of the system and the absence of sources of hazardous chemical potential energy enhances consistently its safety aspects, improving the perception of inherent safety of the Generation IV (G4) reactors in the public opinion. At the moment, due to the abundance of the new fossil resources, the competitiveness of Nuclear Power Plants is severely challenged, this aspect representing the most difficult to manage, besides the public acceptability. Moreover, for G4 reactors, an additional "cost premium" associated with the innovative technological concept has to be taken into account. Conversely, looking at the mid-term future, the real economical comparison has to be performed considering as competing sources, according to the IPCC recommendations and constraints enacted by the European Community, only CO2 free sources. In this context, economical competitiveness could be regained depending on the "cost premium" to be added to fossil fuels to become CO2 free, through the improvement of the carbon separation and storage techniques. The intrinsic lead properties (e.g.: low absorption cross section) permit to easily design LFR flexible cores, optimized with respect to a number of possible goals, as a long-lived core with minimal reactivity swing intended for battery concepts, or what is called an "adiabatic" core, where the entire Pu and MA inventory in the spent fuel can be indefinitely reused in a closed fuel cycle. The latter option allows to limit the waste throughput to the fission products only (along with the-unavoidable-losses from fuel reprocessing), and to benefit of natural resources minimization. These are both specific Generation IV goals envisioned to reach nuclear energy sustainability. An overall fuel cycle balance in a scenario with a step by step introduction of LFR reactors fleet grown in a specific geographical area, is in details analyzed in [1] and presented in this conference..