Fundamental Research on Radiochemistry of Geological Nuclear Waste Disposal

Area of Science:

• Nuclear chemistry and geochemistry
• Environmental science
• Materials science

Background:

• Switzerland stores 5 x 10^19 Bq of radioactive waste from nuclear power, medicine, industry, and research.
• Deep geological disposal is the globally recognized sustainable solution for long-term radioactive waste management.
• The Swiss waste disposal concept integrates engineered and geological barriers for enhanced safety.

Purpose of the Study:

• To investigate radionuclide thermodynamics and geochemistry within deep geological repositories.
• To understand the factors influencing radionuclide mobility, speciation, and radiological impact.
• To provide a fundamental understanding of radionuclide release, retention, and transport mechanisms.

Main Methods:

• State-of-the-art radiochemical laboratory investigations.
• Analysis of chemical thermodynamics and structural chemistry.
• Multidisciplinary approach incorporating fluid dynamics, geo-, and radiochemistry.

Main Results:

• Established a fundamental understanding of radionuclide behavior in repository environments.
• Identified the influence of chemical speciation and background nuclides on radionuclide mobility.
• Characterized radionuclide release, retention, and transport mechanisms over 30 years of research.

Conclusions:

• Deep geological disposal is a viable and sustainable solution for Swiss radioactive waste.
• A comprehensive understanding of geochemical processes is crucial for repository safety assessment.
• Continued research in radionuclide geochemistry is essential for ensuring the long-term safety of nuclear waste disposal.