A sustainable tritium fuel cycle is essential for commercial fusion, requiring onsite breeding using neutrons from the D-T reaction. Tritium can only be bred from lithium-6, so robust engineering solutions are needed for exposing lithium to neutrons. Using lithium in ceramic form is a promising approach, overcoming the reactivity challenges of liquid lithium.
However, significant materials challenges remain—particularly in understanding and optimising tritium extraction from solid ceramics. This project, aims to address these challenges through:
• Atom probe tomography to map deuterium and tritium in breeder ceramics, correlating with microstructural features.
• Developing scalable manufacturing routes for lithium breeder ceramics, enabling controlled meso- and microstructures for efficient tritium extraction.
In the first phase, lithium ceramics (orthosilicates, metatitanates, octo-lithium compounds, Li₂O) will be produced and charged with deuterium (as a surrogate for tritium), using advanced hydrogen charging setups at Oxford. Atom probe tomography and correlative microscopy will be used to develop protocols for mapping isotope locations and understanding microstructural effects. These methods will then be applied to neutron-irradiated ceramics containing tritium, using samples from the Tri-Breed under LIBRTI programme funding.
The second phase will build on recent advances in ceramic processing at Oxford University, focusing on controlling density and porosity for easier tritium extraction. While fully dense ceramics can be produced at kilogram scale, open porosity is needed to ensure tritium is not trapped deep within the material. The project will develop and characterise new manufacturing routes for open-porosity ceramics, using techniques from X-ray CT to atom probe analysis, previously employed by Oxford. Structures larger than the typical pebble sizes–and therefore cheaper to produce- with equal or better flow paths and extraction efficiency will be explored.
Finally, neutron irradiation (via NNUF at Birmingham) and the developed atom probe methods will be used to assess tritium removal efficiency in these optimised ceramics and compared to standard methods such as TDS .
This project is co funded by Kyto Fusioneering.
