Abstract

The report examines strategies for handling transuranic elements (TRU) such as plutonium and minor actinides, which pose long-term challenges for radioactive waste management and nuclear safeguards. Under the auspices of the Nuclear Energy Agency’s Expert Group on Advanced Fuel Cycle Scenarios, this report explores how different reactor technologies and international collaboration could stabilise TRU inventories over 300-year scenarios. The study evaluates transitions from traditional pressurised water reactors (PWR) to advanced systems, such as mixed oxide (MOX)-fuelled PWRs, sodium-cooled fast reactors (SFR), and accelerator driven systems. Two phases were completed: Phase 1 assessed a wide range of TRU-burning scenarios; Phase 2 focused on eight promising pathways, benchmarking their performance using multiple simulation codes. Key findings include many advanced reactor fleets can stabilise plutonium inventories; effective minor actinide recycling is essential to prevent long-term TRU growth; and international fuel sharing, such as one nation supplying spent fuel to another deploying advanced reactors, supports smoother transitions without hindering TRU stabilisation. The report highlights multiple pathways to stabilise TRU, providing insights for R&D, policy and international collaboration on sustainable nuclear fuel cycle management.