IAEA Uses Natural Radioactivity to Help Countries Manage Coastal Sediment

Researchers developed and tested portable gamma ray sensors capable of mapping sediment radioactivity in real time along beaches and underwater environments.

The International Atomic Energy Agency (IAEA) is supporting countries in improving coastal management by using natural radioactivity as a tool to track sediment movement. Many coastal regions face challenges from erosion and shifting sediments, which threaten beaches, ecosystems, infrastructure, and local economies.

By analysing the naturally occurring radioactivity in sediments, scientists can trace the sources, transport patterns, and deposition of materials without introducing artificial tracers, which can be restricted under local regulations. This method offers an environmentally safe and efficient way to understand coastal dynamics and improve decisions on erosion control and harbour maintenance.

Collaborative Research Across 14 Countries

Since 2021, the IAEA has led a Coordinated Research Project (CRP) bringing together institutions from 14 countries, including Brazil, Canada, Egypt, Ghana, Greece, India, Kenya, Malaysia, Morocco, Netherlands, South Africa, Spain, and Tunisia. Researchers developed and tested portable gamma ray sensors capable of mapping sediment radioactivity in real time along beaches and underwater environments.

These efforts were complemented by geostatistical analysis, computational fluid dynamics models, and Monte Carlo simulation algorithms. These tools helped predict sediment behaviour, optimise tracer quantities, and link radioactivity maps to sediment properties such as grain size and mineral composition.

Practical Applications for Coastal and Harbour Management

The CRP demonstrated that monitoring natural radionuclides can be a game changer for coastal management. Authorities can track sediment pathways, measure transport rates, and optimise dredging operations without the need for additional radioactive sources. The resulting data support evidence-based decision-making, reduce operational costs, and enhance the protection of coastal infrastructure and ecosystems.

Celina Horak, Head of the IAEA Radiochemistry and Radiation Technology Section, said, "By simply monitoring naturally occurring radioactivity, countries can gain actionable insights to manage their coastlines more efficiently and sustainably."

The project's results have been published in 40 peer-reviewed articles and 50 conference proceedings, forming the basis for six PhD and Master's theses. While initial work focused on demonstrating feasibility, the IAEA plans follow-up projects emphasising practical applications and direct involvement from coastal managers and government authorities to translate scientific results into decision-support tools.

By combining nuclear science, advanced modelling, and environmental monitoring, the IAEA is helping countries around the world address coastal erosion, optimise dredging, and better understand sediment dynamics, ensuring that shorelines, ecosystems, and communities are more resilient for the future.