Prospects for Closing the Nuclear Fuel Cycle via Pyroprocessing and Dehalogenation of Fluoride-Based Molten Salt...

Advanced reactor development presents an opportunity to close the nuclear fuel cycle by integrating proven pyroprocessing and waste disposition principles in parallel with reactor design. In liquid-fueled molten salt reactors (MSRs), fission products accumulate directly in the circulating salt, necessitating periodic processing to maintain reactivity and thermophysical performance. Closing the fuel cycle therefore requires selective separation and recycling of actinides coupled with effective treatment of secondary salt waste streams. This Perspective examines the technical constraints governing fluoride-based MSR fuel recycling and argues that electrochemical selectivity is a tractable design challenge. In particular, the limited separation margins between actinides and lanthanides in fluoride salts require electrochemical strategies that exploit cathode activity reduction, rigorous redox control, and fluoride-compatible processing conditions. We further contend that dehalogenation of fission-product-bearing salt is an enabling step for waste minimization and actinide recycle. By framing these coupled challenges within an integrated, fluoride-compatible pyroprocessing strategy, this work identifies key design levers and research priorities required to enable continuous actinide recycling and sustainable MSR deployment.