



Molten Salt Reactors (MSRs) represent an innovative option for safer and more sustainable nuclear energy.
They use liquid chloride salts containing actinides, enabling the closure of the nuclear fuel cycle.
During operation, these salts become enriched with fission products and impurities, making chemical treatment necessary.
Enrichment in chlorine-37 aims to limit the formation of chlorine-36, a long-lived radioactive isotope.
Controlling and recycling chloride ions is therefore a major challenge.
The CEA is developing a hydrometallurgical precipitation process to recover enriched chlorine in solid form.
This process is compatible with the La Hague reprocessing plant, in partnership with Orano.
The research focuses on the influence of actinides and fission products on the precipitation reaction and their retention in the solid.
The solubility and purity of the precipitate are studied using various physicochemical techniques.
Purification protocols are optimized when contamination is detected.
Once purified, the solid is recycled to produce reusable chlorine, notably through electrolysis or redox reactions.
This work contributes to the development of innovative reactors and benefits from strong scientific and industrial support.

