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中瀬 正彦*; 竹下 健二*; 小林 徹; 塩飽 秀啓; 矢板 毅
Separation Science and Technology, 50, p.2832 - 2835, 2015/05
被引用回数：1 パーセンタイル：4.99(Chemistry, Multidisciplinary)3価ランタノイドや3価アクチノイドの分離は高レベル廃液処理における重要な課題である。本研究では、2,2'-ビピリジルとランタノイドの錯体の構造と配位能力の関係をX線回折法やUV滴定法により検討した。その結果、NdからErへとイオン半径が減少するのに伴い、2,2'-ビピリジルの窒素とランタノイド間の結合距離やN-Ln-Nの結合角は減少し、2,2'-ビピリジルのピリジル基間の2面角が大きくなること、また、錯形成定数は増大することが分かった。このような構造と錯形成能力との関係に関する情報は、より高効率なランタノイドやアクチノイド分離剤を設計するうえで重要である。
鈴木 伸一; 小林 徹; 矢板 毅
no journal, ,
The amide compounds like N,N-dialkylamide showed good performance to recover actinide from spent nuclear fuels. The extraction properties of actinide elements with these amide compounds were investigated by lots of researchers. One of the most important properties of above organic compounds for adapting nuclear fuels cycle is stability for radiation of actinide and fission products. The items to examine in a radiolysis study are evaluation of (1) stability of organic compounds themselves, (2) influence of degradation products to decontamination factor, and (3) removal degradation products from organic phase. In this study removal investigation of carboxylic acid and secondary amine as N,N-dialkylamide degradation products are carried out. As a result of above treatment, the carboxylic acid was removed easily by scrubbing with alkaline solution like NaOH solution. However secondary amine could not remove by alkaline scrubbing, these compounds remained in organic phase. Furthermore, secondary amine extracted some fission products which stand for decrease of decontamination factor. So we studied secondary amine recovering with inorganic ion-exchange resin. An investigated resin were commercial resin having sulfo group like SO
. We obtained more than 99% recovery efficiency of secondary amine with sulfo group resin treatment.
矢板 毅; 小林 徹; 松村 大樹; 鈴木 伸一
no journal, ,
To improve fundamental theories regarding molecular design for f-elements extractant, coordination dynamics of the unsymmetrical N,O-mixed heterodonor ligand, N-octyl-N-tolyl-1,10-phenanthroline-2-carboxamide(PTA), with lanthanide and actinide were investigated by time dependent energy dispersive X-ray absorption fine structure (TD-DXAFS) method. In addition to PTA, symmetrical 1,10-phenanthroline (Phen) was used as comparison. The time dependent radial structure function of DXAFS showed that PTA has slightly delayed on achieving equilibrium of coordination structure with lanthanide and chemical shift value, compared to symmetrical Phen. The shift direction of absorption edge DXAFS spectrum for the tetravalent uranium was positive while that for the trivalent europium was negative. This result suggests that uranium formed covalent bond with N donor atoms, and lanthanide formed ionic bond. This is because chemical shift direction depends on electron density of each ion. In this presentation, stepwise changes of coordination structure and electronic structure of the metal-ligand complexes during interaction will be discussed in detail from the EXAFAS parameters.
