Strontium-90 levels in seawater southeast of Jeju Island during 2021–2023

Abstract

This study introduces an efficient method for determining 90Sr activity levels in seawater, reducing the processing time to <3 h for 50 L of seawater. The key feature of the proposed method is the chemical separation of 90Y when it is in equilibrium with 90Sr, which is achieved by utilizing custom-made sample-loading equipment and an automated radionuclide separation instrument. As a result, the procedure consistently yields a recovery rate > 90 % for 90Y. Investigations of 90Sr levels were conducted in the ocean southeast of Jeju Island from November 2021 to January 2023. Owing to the regional ocean circulation, this region was among the first within the Korean Peninsula to experience the impact of the Fukushima-accident-derived radionuclides. Throughout the investigation period, the observed 90Sr activity concentration ranged from 0.57 to 1.0 Bq m−3. No distinct temporal variation of 90Sr was observed in the selected area during the investigation.