Simultaneous separation of Am and Cm from Nd and Sm by multi-step extraction using the TODGA-DTPA-BA-HNO system

TODGA-DTPA-BA, HNO抽出系を用いる多段抽出によるNdとSmからAmとCmの同時分離

佐々木 祐二  ; 森田 圭介 ; 松宮 正彦*; 中瀬 正彦*

Sasaki, Yuji; Morita, Keisuke; Matsumiya, Masahiko*; Nakase, Masahiko*

AmとCmをNdとSmから分離する技術は原子力分野で重要である。すべてのランタノイド(Ln)と3価のアクチノイド(An)イオンはDGA化合物で抽出される。加えて、TODGAと水溶性のDTPAを組み合わせると比較的高いLn/An分離比を得ることができる。ここでは、DTPAを改良したDTPA-BAを用いてLn/An分離を試み、比較的高い分離比(8)を得ることができた。次に多段抽出を行い、その結果94.7%のNdと4.7%のAm+Cmを有機相に、5.3%のNdと95.3%のAm+Cmを水相に回収することができた。

The simultaneous separation of Am and Cm from lanthanides is important for atomic energy fields. All lanthanides, Am, and Cm can be extracted by diglycolamide (DGA). In addition, relatively high separation factors between An and Ln were obtained by the extraction system of TODGA, DTPA (diethylenetriamine-pentaacetic acid) and HNO. In this work, DTPA-BA (diethylenetriamine-triacetic-bisamide), which is an improved version of DTPA, was employed for the separation of Ln and An. A relatively high separation factor (approximately 8) for actinides/lanthanides was obtained. Then, the multi-step extraction was performed. Thus, the recoveries of 94.7% for Nd and 4.7% for Am and Cm in organic phase, and 5.3% Nd and 95.3% for Am and Cm in aqueous phase were obtained.