X-ray diffraction phase analysis of single hot particles from Chornobyl.

Area of Science:

• Nuclear Chemistry
• Materials Science
• Environmental Science

Background:

• Structural stability of Chornobyl nuclear fuel particles remains poorly understood, hindering environmental risk assessments.
• No prior phase analyses of these dispersed nuclear fuel particles have been published.

Purpose of the Study:

• To conduct a comprehensive phase analysis of individual nuclear fuel hot particles from the Chornobyl Exclusion Zone.
• To determine the stability of different phases under real-world environmental conditions.

Main Methods:

• High-resolution synchrotron X-ray diffraction combined with triple-axis rotation.
• Collection of full Bragg reflection data from individual hot particles.

Main Results:

• Identified stable phases including uranium dioxide (UO2), U3O8, U4O9, and Zr-mixed phases.
• Largely intact UO2 and U4O9 structures were detected, indicating stable frameworks.
• These stable matrices likely continue to contain fission products and actinides.

Conclusions:

• The structural integrity of uranium oxide matrices in Chornobyl hot particles has been retained after long-term environmental exposure.
• Results support further investigation into contamination models and waste management strategies for nuclear accident sites.