Full range determination of ²²²Rn at the watershed scale by liquid scintillation counting

Area of Science:

• Environmental Science
• Hydrogeology
• Radiochemistry

Background:

• Groundwater-surface water interactions are crucial for watershed management.
• Radon-222 (Rn) is a valuable tracer for quantifying groundwater discharge into surface water bodies.
• Accurate measurement of Rn requires optimized analytical protocols and calibration.

Purpose of the Study:

• To optimize analytical protocols for liquid scintillation measurements of Rn in surface and groundwater.
• To calibrate scintillometer efficiency across a relevant range of Rn activities.
• To assess the applicability of Rn measurements in a Canadian watershed.

Main Methods:

• Development and optimization of direct measurement and Rn-extraction protocols.
• Liquid alpha scintillation counting for Rn-222 analysis.
• Scintillometer efficiency calibration using international standards (0.5-35 Bq/L).
• Application of methods to surface water and groundwater samples from a Canadian watershed.

Main Results:

• Optimized protocols provide reliable Rn-222 measurements.
• Calibrated scintillometer ensures accurate quantification across the target activity range.
• Successful application in a real-world watershed setting.

Conclusions:

• Optimized Rn-222 measurement techniques are effective for identifying groundwater contributions to surface water.
• The study provides a validated methodology for environmental applications.
• Accurate Rn-222 analysis is essential for understanding hydrological processes.