Separation of americium from plutonium-solvent extraction raffinate and conversion to americium oxide

Sugikawa, Susumu; Nakazaki, Masato; Kimura, Akihiro; Kida, Takashi*; Kihara, Takehiro*; Akabori, Mitsuo; Minato, Kazuo; Suda, Kazuhiro*; Chikazawa, Takahiro*

Nihon Genshiryoku Gakkai Wabun Rombunshi, 6(4), p.476 - 483, 2007/12

https://doi.org/10.3327/taesj.J06.074

A one-step simple extraction chromatography method using TODGA (-tetraoctyl-diglycolamide) adsorbent column has been developed to separate the americium from plutonium-solvent extraction raffinate. The raffinate contained Am(620 mg/), Np(107 mg/), Ag(2000 mg/), Fe(290 mg/), Cr(38 mg/), Ni(52 mg/) and trace of TBP. Small-scale and scale-up tests for separation of americium and conversion to americium oxide were carried out in NUCEF. Efforts were made to increase yield and purity of americium. The americium was separated with 83-92% yields and 97-98% purities by small-scale tests and 85-95% yields and 98-99% purities by scale-up tests. The yields for conversion of americium nitrate solution to americium oxide were 89-100% by small-scale tests and 85-96 % by scale-up tests. Approximately 1.8 gram americium oxide was recovered from 6 litres of the raffinate and supplied for the research on the high-temperature chemistry of TRU.

Characteristics of MOX dissolution with silver mediated electrolytic oxidation method

Umeda, Miki; Nakazaki, Masato; Kida, Takashi; Sato, Kenji; Kato, Tadahito; Kihara, Takehiro; Sugikawa, Susumu

JAERI-Tech 2003-024, 23 Pages, 2003/03

JAERI-Tech-2003-024.pdf:0.98MB

MOX dissolution with silver mediated electrolytic oxidation method is planned for the preparation of plutonium nitrate solution to be used for criticality safety experiments at Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF). Silver mediated electrolytic oxidation method uses the strong oxidisation ability of Ag(II) ion. This method is thought to be effective for the dissolution of MOX, which is difficult to be dissolved with nitric acid.In this paper, the results of experiments on dissolution with 100 g of MOX are described. It was confirmed by the results that the MOX powder to be used at NUCEF was completely dissolved by silver mediated electrolytic oxidation method and that Pu(VI) ion in the obtained solution was reduced to tetravalent by means of NO purging.