Reprocessing and direct storage of nuclear fuels

This teaching unit covers the notions necessary to understand the dissolution or leaching/alteration of ceramic materials. In the case of nuclear fuel materials, the aim is to analyze the degradation phenomena under aggressive conditions representative of a recycling or reprocessing stage, but also those related to their alteration, under "softer" conditions, representative of a direct storage in deep geological formation.

Hourly volumes* :

            CM : 12h

            TD : 8h

The objective of this teaching unit is to address the problems related to the behavior of ceramic materials under chemical stress (dissolution, leaching, alteration). The aim is to establish the drivers of dissolution (conditions representative of a reprocessing operation) or leaching (conditions representative of a direct storage) of a ceramic material by considering not only the solid (microstructure, densification, texture, topology, composition) but also the species in solution (acid-base, redox or complexation drivers).

Fuel cycle: from mining to waste management

Synthesis and remanufacturing of combustible materials

Continuous control

• Dissolution/leaching of ceramic materials for reprocessing or storage in the medium or long term:
• Description of experimental protocols:
• Analytical strategy related to the evaluation of elemental releases
• Characterization tools for evolving interfaces
• Kinetic approach:
• Effect of structural, microstructural and textural parameters
• Correlations: synthesis - sintering - dissolution
• Effect of chemical "stresses" (acid-base, redox, complexation, ...)
• Thermodynamic approach:
• Description of the interface modifying phenomena
• Identification and control of saturation phenomena (neoformed phases, dissolution indissolves) - Impact on the short, medium and long term behavior
• Irradiation/dissolution or leaching couplings: radiolytic effects.

The lectures and tutorials will be complemented by bibliographic tutorials as well as several case studies dealing with the reprocessing of spent nuclear fuels or their long-term behavior with a view to direct storage in deep geological formations

Administrative contact(s): Secretariat Master Chemistry

master-chimie @ umontpellier.fr (master-chimie @ umontpellier.fr)