(TBP-TOA)/n-dodecane-HNO3 추출 계에 의한 Tc, Np, U의 공추출 및 순차분리 평가

• 영문명: Evaluation of co- and sequential separation for Tc, Np and U by a (TBP-TOA)/n-dodecane-HNO3 extraction system
• 발행기관: 한국방사성폐기물학회
• 저자명: 이일희 임재관 정동용 양한범 김광욱
• 간행물 정보: 『Journal of Nuclear Fuel Cycle and Waste Technology (JNFCWT)』Vol.5 No.2, 133~143쪽, 전체 11쪽
• 주제분류: 공학 > 공학일반
• 파일형태: PDF
• 발행일자: 2007.06.30

국문 초록

본 연구는 실제 HLW 수준의 다성분 계 모의 용액으로부터 Zr-DEHPA/NDD-HNO3 금속함유 추출 계에 의한 Am-Cm/RE 원소의 공분리 및 이의 상호분리 연구를 수행하였다. 우선 금속함유 추출제인 Zr-DEHPA를 자체 제조하고, 제 3상 방지 조건 결정과 질산 농도, DEHPA 농도, Zr 함유량 등이 공추출에 미치는 영향을 평가하여 최적 조건으로 (15g/L Zr-1M DEHPA)/NDD-1M HNO3 추출 계를 설정하였다. 이때 추출률은 Am (81%), Cm (85%), RE 원소 (80% 이상), Mo (98%), Fe (85%), U (98%), Np (73%), 기타 원소 (5% 이하) 등으로 Am-Cm/RE의 공분리 적용성은 양호하나, U, Np, Mo, Fe의 선제거가 필요하고 특히 제 3상 형성 유발 물질인 Zr이 거의 함유되지 않아야 한다. 그리고 공추출된 Am-Cm/RE를 Am-Cm (역추출제 : 0.05M DTPA-1M Lactic acid-pH 3.6) → RE (역추출제 : 5M HNO3) 순으로 상호 분리하여 각각의 분리계수를 평가하였으며 이때 Am은 65.4%, Cm은 63.9% RE 원소(Y 제외)는 85% 이상이 역추출 되었다.

영문 초록

This study was performed to evaluate the co- and mutual separation for Am, Cm and RE elements from the simulated multi-component solution equivalent to real HLW level by a Zr-DEHPA(di-(2-ethylhexyl) phosphoric acid containing Zirconium)/NDD(n-dodecane)-HNO3 extraction system. Zr-DEHPA was self-synthesized and the optimal condition of (15g/L Zr-1M DEHPA)/NDD-1M HNO3 was selected taking into consideration of prevention of the third phase, and effects of concentration of DEHPA, nitric acid and impregnant amount of Zr on the co-extraction of Am, Cm and RE. In that condition, the extraction yields were 81% (Am), 85% (Cm), more than 80% (RE elements), 98% (Mo), 85% (Fe), 98% (U), 73% (Np), and less than 5% (other elements) so that the system developed for the co-extraction of Am-Cm/RE was proved to be available. For that, however, U, Np, Mo and Fe was elucidated to have to be removed in advance, and Zr inducing the third phase formation was found to be practically excluded. The co-extracted Am-Cm/RE were sequentially separated in an order of Am-Cm (stripping agent : 0.05 M DTPA-1M Lactic acid of pH 3.6) → RE (stripping agent : 5M HNO3), and then their separation factors were evaluated. At above conditions, Am of 65.4%, Cm of 63.9%, RE (except for Y) of more than 85% were stripped.

키워드

아메리슘 세륨 희토류 원소 Zr-DEHPA 공추출 상호 분리. Am Cm Rare Earth elements Zr-DEHPA Co-extraction Mutual separation