Uranium and plutonium extraction from nitric acid by -di(2-ethylhexyl)-2,2-dimetnylpropanamide (DEHDMPA) and -di(2-ethylhexyl)butanamide (DEHBA) using mixer-settler extractors

Ban, Yasutoshi  ; Hotoku, Shinobu ; Tsubata, Yasuhiro   ; Morita, Yasuji  

Extraction properties of -di(2-ethylhexyl)-2,2-dimethylpropanamide (DEHDMPA) for nitric acid, U(VI), and Pu(IV) were studied, and the distribution ratio equations were derived for each chemical species. A continuous counter-current experiment was performed using mixer-settler extractors with two types of monoamides, DEHDMPA and -di(2-ethylhexyl)butanamide (DEHBA), as extractants. DEHDMPA exclusively extracted U from the feed, and the ratio of U recovered in the U fraction stream was 99.93%. Almost all Pu were extracted by DEHBA, and the recovery of Pu in the U-Pu fraction stream was 99.94%. Concentrations of U and Pu in mixer-settlers were calculated using a simulation code, which confirmed that the calculation was effective for estimating the U concentration in the U fraction stream, and the U and Pu concentrations in the U-Pu fraction stream.