Development of a chloride recovery process by precipitation – Application to molten salt reactors
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.
TOMOGLASS: Gamma Emission Tomography Applied to the Radiological Characterization of Glass Residues from the Cold Crucible Vitrification Process
The TOMOGLASS project aims to develop an innovative gamma tomography system capable of operating in high-activity environments to characterize in three dimensions the glass residues resulting from the vitrification process of nuclear waste. The objective is to precisely locate platinum-group inclusions, which are poorly soluble in glass, in order to improve the understanding and control of the process. The system is based on a compact gamma imager integrating high-resolution pixelated CZT detectors, pinhole-type collimation, and mounting on a robotic arm. It will enable multi-isotopic reconstruction using advanced tomographic algorithms. This project is part of the modernization of the La Hague facilities and the integration of digital technologies within the framework of the factory of the future.
The first phase of the project will consist in demonstrating the feasibility of implementing a spectro-imager prototype in a constrained environment, building on existing technological components: detection modules and acquisition electronics based on the HiSPECT technology, and image reconstruction algorithms developed at CEA-Leti. The work will focus on conducting a multi-parameter study through numerical simulations (Monte Carlo calculation code) to design an optimized measurement system, and to generate simulated datasets for various representative measurement configurations. Once the concept has been validated, the work will continue in year N+1 with the assembly of the prototype components and their integration on a robotic arm. Experimental tests may then be carried out to demonstrate the system in a representative environment.