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  • Author or Editor: M. Nogami x
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Abstract  

The resistance against radiation of the tertiary pyridine resins synthesized for the treatment of spent nuclear fuels and high level radioactive waste was evaluated. After irradiation at 10 MGy, only approximately 10% or less of the exchange groups were lost in HCl solutions regardless of their concentrations, while 3040% were lost in HNO3. The pyridine resin has shown remarkable resistance against radiation particularly in HCl solution. It has been revealed that the decomposition of pyridine type resins results from the scission of the principal chains. An irradiation study was conducted also on the quaternary ammonium resins. Quatemization ratio was found to be reduced in HNO3 solutions at 10 MGy irradiation.

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Abstract  

Resins with monoamides as functional groups have been synthesized and their fundamental adsorption behaviors have been examined for selective recovery of uranium(VI) from nitric acid media. The resins synthesized with porous silica support showed greatly different adsorptions for U(VI) depending on the chemical structures of the functional group. Some resins show little or no adsorption for U(VI) from 0.1 to 6 mol/dm3 HNO3. While, resins consisting of dimethylacrylamide (DMAA) showed an increasing adsorption with an increasing concentration of HNO3 up to 9 to 12 mol/dm3. Other ions were not found to be adsorbed onto Silica-DMAA under similar solution conditions, which means that the resin is selective for U(VI) in HNO3 media.

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Abstract  

Adsorptivity of polyvinylpolypyrrolidone (PVPP), a candidate resin with selectivity to U(VI) in HNO3 media, to various metal ions was examined. It was found that PVPP has a strong adsorptivity to U(VI) in wide concentration range of HNO3. The Scatchard plot analysis revealed that the adsorption of U(VI) by PVPP occurs at plural binding sites. The infrared spectroscopic analysis suggested that the strong binding site is due to the coordination of the carbonyl oxygen atom and the nitrogen atom in the pyrrolidone ring to UO2 2+. It was also found that fission product ions except Re(VII) as the simulant of Tc(VII) and Pd(II) are not adsorbed onto PVPP. The adsorptivities to Tc(VII) and Pd(II) species are weak, indicating that U(VI) can be separated from other metal ions by PVPP.

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