Economical radioactive soil treatment technology is essential to safely and efficiently treat of high-concentration radioactive areas and contaminated sites during operation of nuclear power plants at home and abroad. This study is to determine the performance of BERAD (Beautiful Environmental construction’s RAdioactive soil Decontamination system) before applying magnetic nanoparticles and adsorbents developed by the KAERI (Korea Atomic Energy Research Institute) which will be used in the national funded project to a large-capacity radioactive soil decontamination system. BERAD uses Soil Washing Process by US EPA (402-R-007-004 (2007)) and can decontaminate 0.5 tons of radioactive soil per hour through water washing and/or chemical washing with particle size separation. When contaminated soil is input to BERAD, the soil is selected and washed, and after going through a rinse stage and particle size separation stage, it discharges decontaminated soil separated by sludge of less than 0.075 mm. In this experiment, the concentrations of four general isotopes (A, B, C, and D which are important radioisotopes when soil is contaminated by them.) were analyzed by using ICP-MS to compare before and after decontamination by BERAD. Since BERAD is the commercial-scale pilot system that decontaminates relatively large amount of soil, so it is difficult to test using radioactive isotopes. So important general elements such as A, B, C, and D in soil were analyzed. In the study, BERAD decontaminated soil by using water washing. And the particle size of soil was divided into a total of six particle size sections with five sieves: 4 mm, 2 mm, 0.850 mm, 0.212 mm, and 0.075 mm. Concentrations of A, B, C, and D in the soil particles larger than 4 mm are almost the lowest regardless of before and after decontamination by BERAD. For soil particles less than 4 mm, the concentrations of C and D decreased constantly after BERAD decontamination. On the other hand, the decontamination efficiency of A and B decreased as the soil particle became smaller, but the concentrations of A and B increased for the soil particle below 0.075 mm. As a result, decontamination efficiency of one cycle using BERAD for all nuclides in soil particles between 4 mm and 0.075 mm is about 45% to 65 %.

발전소 해체 및 핵종누출 시 원자력 관련 시설 주변의 방사성오염 토양은 주민의 거주 및 공업용지로의 재사용을 위해 토양 제염이 불가피하다. 본 논문에서는 기존 토양복원 기술을 생물학적, 물리/화학적, 열적 처리로 분류하고 각 기술의 원리 및 처리 물질을 분석 및 조사를 통해 방사성물질로 오염된 토양에 적용 가능한 기술을 선정하였다. 선정된 기술을 평가하기 위 해 경제성, 적용성, 기술성을 고려하였다. 또한 High, Medium, Low로 가중치를 적용하여 평가하였다. 이에 따른 결과값을 바탕으로 방사성물질로 오염된 토양에 가장 적합한 토양제염 방법을 제시하고자 한다.

10년 이상 된 방사능오염 토양에서 동전기적 방법에 의한 Cs과 Co의 제염효율을 높이기 위해 HSO과 시트르산을 첨가제로 사용했다. 동전기 토양복원 컬럼의 방출수 평균속도는 2.0 cm/min이고, 10일 동안 방출된 토양폐액의 부피는 컬럼의 3.6 공극부피다. 10일간 Cs 의 제거효율이 54%에 불과한 반면에, Co는 97%나 제거되었다. 이것은 Cs의 흡착평형계수가 Co 보다 크기 때문이라고 생각된다. 본 연구에서 제시한 수학적 모델에 의한 컬럼 잔류 오염도는 실험 오차 범위에서 실험결과와 잘 일치하였다.