The effectiveness of the ELSY concept with respect to minor actinide transmutation capability

The task of partitioning and transmutation (PT) aims at the sustainability of new global nuclear scenarios for energy production, required by a continuously growing demand. The nuclear renaissance boosted by the breaking need of a reduction in CO2 emissions, together with increasing safety and security requirements, is creating a clear interest in the Generation-IV philosophy. In particular, an effective management of minor actinides (MA) and their multi-recycling in innovative fast spectrum systems can lead to a minimisation of high-level wastes (HLW) to be disposed of in geological repositories. This study presents a PT application based on the European Lead-cooled System (ELSY), the 600 MWe Gen-IV lead-cooled fast reactor (LFR) under investigation in Europe within the 6th EURATOM Framework Programme. An “adiabatic” core configuration is investigated here, for a system which can maintain a constant amount of both MA and plutonium during the whole fuel cycle, even without either axial or radial blankets. It is shown that an equilibrium concentration of MA exists, for which its production rate is exactly compensated by its transmutation rate. Any other concentration may enhance either their production or removal in such a way as to allow the system to evolve almost exponentially towards the equilibrium state. The practical feasibility of such an equilibrium core is then analysed: acceptable operative conditions might lead to a “sustainable” nuclear system, the overall net outcome of which is the production of energy by burning a feed stream of uranium from one side, and the discharge of fission products (FP) only from the other side.