Radium migration through clay liners at waste disposal sites

Area of Science:

• Environmental Science
• Geochemistry
• Nuclear Chemistry

Background:

• Industrial plants processing uranium ore generate wastewater containing radionuclides like Radium-226 (226Ra).
• Compacted clay liners in wastewater disposal reservoirs are crucial barriers to prevent radionuclide migration into the environment.
• Understanding 226Ra migration is vital for assessing environmental contamination risks.

Purpose of the Study:

• To evaluate the migration of 226Ra through a compacted clay liner.
• To develop and validate an instrumental method for analyzing 226Ra in soil samples.

Main Methods:

• A novel instrumental method was developed for 226Ra analysis in soils.
• The method involved detector calibration, efficiency determination, background and sample counting, and photo-peak smoothing.
• 226Ra was quantified indirectly by measuring its granddaughter nuclide, 214Bi, at a 609 keV photo-peak.

Main Results:

• The study found that the majority of 226Ra diffusing into the soil was retained in the upper soil layers.
• Only a small percentage of 226Ra migrated to deeper, subjacent soil layers.
• The developed methodology demonstrated high efficacy in tracking radionuclide movement.

Conclusions:

• The developed instrumental method is suitable for assessing radionuclide migration in soil layers.
• This methodology is valuable for environmental impact assessments concerning radionuclide contamination.
• The findings suggest that compacted clay liners can effectively limit the migration of 226Ra from wastewater reservoirs.