Optimised fuels for production of medical radioisotopes This action should involve a multidisciplinary research consortium able to tackle technical aspects of production of fuel for research reactors. It should include EU-based research reactors fuel alongside EU research reactor operators. It should focus on increased safety and, in this context on the qualification phase of fuel elements based on low-enriched uranium. It should further investigate future needs in terms of volume and fuel design requirements in line with relevant data for each EU research reactor type. The action should also prepare technical requirements for the safety of manufacturing, storage, transport and reprocessing of such research reactor fuel. It may include pilot scale experiments. It should take into account the regulatory, legal and economic contexts to propose a sustainable chain of EU-based research reactors’ fuel manufacturing. All actions should be undertaken considering the activities of the Euratom Supply Agency (ESA) in this area [[http://ec.europa.eu/euratom/observatory_radioisotopes.html]].At least 5% of the total action budget must be dedicated to Education and Training activities for PhD students, postdoctoral researchers and trainees supported through the action (see Conditions for the Call- Eligibility and admissibility conditions).The Commission considers that proposals requesting a contribution from the Euratom Programme up to EUR 7.5 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts. The EU remains the major world operator of research reactors and supplier of medical radioisotopes. Low enriched uranium is key to ensure the secure supply of research reactors’ fuel and targets in compliance with the Euratom’s international commitments on non-proliferation. Previous Euratom work programmes (WP2014-2015 and WP2016-2017) already supported research on the safety of low enriched and high-density fuel for research reactors in order to improve understanding of the fuels’ irradiation behaviour and optimise the manufacturing process and modelling. However, much remains to be done in this field, in particular in terms of fuel qualification, considering the requirements of the entire supply, operation and decommissioning chain. This action will sustain the EU’s capacity in the production of medical radioisotopes by ensuring the availability of high-performance research reactors. It will thus contribute to health care through provision of innovative medical radioisotopes necessary for diagnostic and therapy. It will further support European industry by giving access to research reactor irradiation capabilities.