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Suzuki, Shinichi; Yaita, Tsuyoshi; Okamoto, Yoshihiro; Shiwaku, Hideaki; Motohashi, Haruhiko*
Physica Scripta, T115, p.306 - 307, 2005/00
In spent fuel reprocessing, distribution behavior of technetium in tri- butyl phosphate (TBP) extraction system is a very complicated. Especially, in the presence of metallic ions, i.e., U(VI), Pu(IV)and Zr(IV)in the TBP extraction system, the extraction of technetium is enhanced by the co- extraction with U, Pu and Zr. The mechanism of co-extraction mechanism of technetium is performed by exchange with nitric acid ion and per-technetate ion. In this research, we perform the structural analysis of technetium complexes in ethanol solution compared with rhenium and manganese complexes by EXAFS. Furthermore we measured some organic complexes and co-extracted complexes of technetium with uranium and zirconium extracted by TBP as compared with those of rhenium.
Suzuki, Shinichi; Sasaki, Yuji; Yaita, Tsuyoshi; Kimura, Takaumi
Proceedings of International Conference ATALANTE 2004 Advances for Future Nuclear Fuel Cycles (CD-ROM), 4 Pages, 2004/06
An innovative chemical separation process (ARTIST: Amide-based Radio-resources Treatment with Interim Storage of Transuranics) was proposed for the treatment of spent nuclear fuel. The main concept of ARTIST process is to recover and stock all actinides (An) and to dispose the fission products (FP). One of the main purposes of this process is selective isolation of uranium. Since the brached alkyl type N,N-dialkyl-monoamides (BAMA) have the steric hindrance on the complexation with metal cations, BAMA can be used to separate An(VI) from An(IV). N,N-di-(2-ethyl)hexyl-2,2-dimethylpropanamide (D2EHDMPA) can recover U(VI) selectively without accumulating Pu(IV) in uranium isolation process. From extraction behavior of Np, D2EHDMPA can extract and separate U(VI) from Np(VI) without reduction from Np(VI) to Np(V) or Np(IV).
Watanabe, Masayuki; Tatsugae, Ryozo*; Morita, Yasuji; Kubota, Masumitsu*
Journal of Radioanalytical and Nuclear Chemistry, 252(1), p.53 - 57, 2002/04
Times Cited Count:7 Percentile:44.35(Chemistry, Analytical)no abstracts in English
Rai, D.*; Rao, L.*; Weger, H. T.*; Felmy, A. R.*; Choppin, G. R.*; Yui, Mikazu
JNC TN8400 99-009, 115 Pages, 1999/01
This report provides thermodynamic data for predicting concentrations of Th(IV), U(IV), Np(IV), and Pu(IV) in geologic environments, and contributes to an integration of the JNC chemical thermodynamic database, JNC-TDB (previously PNC-TDB), for the performance analysis of geological isolation system for high-level radioactive wastes. Thermodynamic data for the formation of complexes or compounds with hydroxide, chloride, fluoride, carbonate, nitrate, sulfate and phosphate are discussed in this report. Where data for specific actinide(IV) species was lacking, the data were selected based on chemical analogy to other tetravalent actinides. ln this study, the Pitzer ion-interaction model is used to extrapolate thermodynamic constants to zero ionic strength at 25C.
*; Sakamoto, Yoshiaki; *; *
Genshiryoku Bakkuendo Kenkyu, 4(1), p.47 - 55, 1997/08
no abstracts in English
; Tachimori, Shoichi; Usuda, Shigekazu; ; ; *
Solvent Extraction 1990, p.699 - 704, 1992/00
no abstracts in English