Reprocessing and direct storage of nuclear fuels

This course covers the concepts needed to understand the dissolution or leaching/alteration of ceramic materials. In the case of nuclear fuel materials, the aim is to analyze degradation phenomena under aggressive conditions, representative of a recycling or reprocessing stage, as well as those linked to alteration under "softer" conditions, representative of direct storage in a 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). It will be a question of establishing the drivers of dissolution (conditions representative of a reprocessing operation) or leaching (conditions representative of 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 remanufacture of combustible materials

Continuous control

• Dissolution/leaching of ceramic materials with a view to reprocessing or medium or long-term storage:
• Description of experimental protocols:
• Analytical strategy related to the evaluation of elementary releases
• Tools for characterizing evolving interfaces
• Kinetic approach:
• Effect of structural, microstructural and textural parameters
• Correlations: synthesis – sintering – dissolution
• Effect of chemical “stresses” (acid-base, redox, complexation, etc.)
• Thermodynamic approach:
• Description of phenomena modifying interfaces
• Identification and control of saturation phenomena (neoformed, undissolved dissolution phases) - Impact on short, medium and long term behavior
• Irradiation/dissolution or leaching couplings: radiolytic effects.

The lectures and tutorials will be supplemented 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): Master of Chemistry secretariat

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