40 Years After Chernobyl Disaster, Scientists Find Radioactive Particles Surprisingly Stable

Scientists have found that tiny radioactive particles released during the 1986 Chernobyl nuclear disaster have retained much of their internal structure even after nearly four decades. The discovery could help researchers better understand the long-term environmental and health risks posed by radioactive contamination.

Researchers from Leibniz University Hannover and the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in Germany examined six radioactive particles collected from the Chernobyl Exclusion Zone in Ukraine. Their findings suggest that some of these particles are more structurally stable than previously understood.

The research has been published in the Journal of Hazardous Materials.

What Did The Study Find?

The scientists studied six microscopic particles measuring between 8 and 50 micrometres. These particles originated from the nuclear fuel and other materials released when the reactor exploded in April 1986.

The researchers identified three broad types of particles based on how they formed during the disaster. Some retained properties similar to the original nuclear fuel, uranium dioxide. Others had become partially or completely fused with a protective layer containing zirconium. A third type formed when the reactor's graphite moderator caught fire, altering the chemical composition of the fuel.

Each type has a different chemical structure, which can influence how it changes when exposed to the environment over long periods.

How Did Scientists Examine The Particles?

To study the particles at the atomic level, the team used a technique called X-ray diffraction analysis. This method allows scientists to investigate the crystal structure of a material by measuring how X-rays interact with it.

The researchers examined the particles from thousands of different angles to build a detailed picture of their internal structure.

The analysis revealed that important parts of the nuclear fuel's crystal structure had remained largely intact. In particular, the researchers identified uranium oxide phases that had retained much of their structural integrity.

These findings suggest that some radioactive particles can hold radioactive substances within their structure for extended periods, potentially limiting how quickly these materials are released into the surrounding environment.

What Does This Mean For The Environment?

The discovery could help scientists improve estimates of how radioactive contamination spreads through soil and other materials around the Chernobyl site.

Understanding how the particles change over time is important for assessing the possible movement of radioactive substances into the environment. The findings could also contribute to improved contamination models and strategies for managing radioactive waste at nuclear accident sites.

However, the researchers cautioned against drawing broad conclusions from the results.

The study examined only six particles collected from two locations. A much larger sample, covering more areas of the exclusion zone, would be needed to understand how widely the findings apply.

Are The Radioactive Particles Still Dangerous?

The findings do not mean that the Chernobyl Exclusion Zone is safe for unrestricted access. Although the examined particles retained much of their internal structure, they remain radioactive. Their long-term behaviour can vary depending on their chemical composition and environmental conditions.

Scientists also need to establish how different particles release radioactive substances over time and how these materials may affect the surrounding environment. The researchers noted that some particles could remain stable for longer than others, making it difficult to draw universal conclusions about contamination and health risks across the region.

The study provides new information about the lasting effects of the 1986 disaster, but further research is needed to understand how radioactive particles behave over longer periods and what this means for the environment and public health.