Soil Washing Technology Demonstration for Removal of Multi-Nuclides in Natural Background Soil

Choong Sup Byun, Suin Lee, Jihyun Kang, Wonseok Park, Dohyung Kim and Jongyoul Lee

Nuclear Division, Beautiful Environmental Construction Co., Ltd., Rm501, Mega center, 124, Sagimakgol-ro, Jungwon-gu, Seongnam-si, Gyeonggi-do

Received 2024-08-13 ; Revised 2024-09-03 ; Approved 2024-10-24

Abstract

Industries that use or produce radionuclides have unintentionally released these substances into surrounding soils and sediments. To address this problem, Beautiful Environmental Construction (BEC) Co. developed the BEC’s Radioactive Soil Decontamination (BERAD) system to remove contaminants and reduce the volume of radionuclide-contaminated soils. Owing to the limited availability of radioactive isotopes such as Co-60, Sr-90, Cs-137, and uranium-contaminated soil, naturally occurring elements in soil were used in this demonstration. The soil was divided into six size fractions via manual wet sieving and the BERAD system. Then, the concentrations of uranium, cobalt, strontium, cesium, and iron in each fraction were measured. The results of both separations showed that a considerable amount of each element is retained in the finer size fractions (<0.2 mm). After BERAD separation, the corresponding values yielded 53% uranium, 45% strontium, 66% cobalt, and 53% cesium in the fine size (<0.2 mm) fractions of 35% by weight. The study found that the concentrations of these elements increased as the particle sizes decreased. Iron and micaceous minerals played a significant role in retaining the elements. The pilot scale BERAD system yielded results that were similar to those obtained via laboratory wet-sieving and was successfully demonstrated as a soil washing technology.

Key Words : Rad-contaminated soil, remediation, soil-washing, uranium, cesium, cobalt, strontium