Molten salt reactor (MSR) technologies are attracting great interest in the public and private sectors for a broad spectrum of nuclear applications worldwide. At the international level, the primary focus revolves around reactor technology, with some attention to safety and licensing. The chemistry of the fuel cycle plays a crucial role in developing and deploying MSRs, as recognised by the members of the NEA Expert Group on Fuel Recycling and Waste Technology (EGFRW) and the IAEA Technical Working Group on Nuclear Fuel Cycle Options and Spent Fuel Management (TWG-NFCO).
To address the challenges of chemical processes and technologies in MSR fuel cycles, the NEA and IAEA jointly organised an international workshop on the chemistry of fuel cycles for molten salt reactor technologies in Vienna, Austria, on 2-6 October 2023. The event gathered more than 40 participants from 13 countries and the European Commission, including MSR developers, research and development (R&D) organisations, regulators and industry experts.
The programme included several technical sessions on MSR concepts and nuclear fuel cycles, salt preparation, online and offline processing, and cross-cutting issues. Each session consisted of technical presentations, a “thoughts from the floor” session to tackle topics of interest not covered by the presentations, and a panel discussion involving all the presenters. During the working sessions, participants could engage in further discussion and work together to identify gaps and R&D needs in the following areas: experimental underpinning, irradiations, monitoring and operation, and irradiated fuel treatment (material and waste streams). Participants also discussed potential ways to address these matters and made recommendations on potential future activities.
As the event confirmed the growing interest in molten salt technologies worldwide, it also stressed the added value international co-operation can bring to the scientific community, MSR developers and future user countries.