Integration of advanced fuel reprocessing for lead-cooled fast reactors: towards a closed fuel cycle

Global interest in nuclear energy is growing, driven by rising energy demand and decarbonization goals. Small Modular Reactors (SMRs) are an attractive solution for sustainable, low-carbon power. The Belgian government made the decision to both support the long-term operation (LTO) of existing water-cooled reactors and drive the development of innovative GenIV lead cooled SMRs. From this initiative, the EAGLES consortium was realized and marks a milestone for LFR (Lead Fast Reactor) development.

Natural uranium resources are limited and declining, while mining has negative environmental impact, affecting ecosystems and groundwater. In addition, the current geopolitical context emphasizes Europe’s need for energy independence to ensure long-term energy security. Meanwhile, global demand is increasing with the expansion of nuclear power and the development of innovative small modular reactors (SMRs), with the IAEA and NEA projecting a tripling of the current nuclear capacity by 2050.

Recycling fertile and fissile materials from spent fuel addresses these limitations, while also facilitating waste management by reducing the waste volume significantly and optionally burning long-lived actinides produced during reactor operation. Progress in Generation IV fuel reprocessing technologies is essential to close the fuel cycle and ensure the sustainability of future SMR fleets. To date there is no industrial-scale experience with fast reactor (FR) fuel reprocessing, highlighting the development needs.

Spent fuel can be reprocessed by aqueous or pyrochemical routes. Fast reactor fuels with high fissile content lead to spent fuel with higher heat load, radiation and fissile content. Pyroprocessing offers a promising alternative to cope with these properties and could enable on-site fuel recycling, reducing transport and storage needs. Countries including the US, South-Korea, Russia, United Kingdom and Japan have advanced this technology over the past decades, demonstrating successful recovery through electroreduction and electrorefining up to pilot scale.

Challenges and improvements remain for pyrochemical processes to scale-up towards industrial level and confirming their compatibility with LFR spent fuel. In addition to improving process selectivity, the presence of Pb in the process has not been investigated, nor its behavior within the molten salts for reprocessing purposes. Implementing plutonium separation from the long-lived actinides would benefit remanufacturing of fast reactor mixed oxide (MOX) fuel by proven processes and consequently close the fuel cycle.