Am, Cm recovery from genuine HLLW by extraction chromatography

Watanabe, Sou; Sano, Yuichi; Kofuji, Hirohide; Takeuchi, Masayuki; Shibata, Atsuhiro; Nomura, Kazunori

doi:10.1007/s10967-018-5853-x

Cited by 16 publications

(11 citation statements)

References 10 publications

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“…The value of C/C0 above 1 must be elution of elements from CMPO/SiO2-P as a result of competitive adsorption of cations. Ba(II), Sr(II) and Ru(III) were not adsorbed by CMPO/SiO2-P, and these results reasonably agree with the previous report 2 . RE(III)-Y(III), La(III), Ce(III), Nd(III), Sm(III) and Eu(III)were adsorbed by the column, and they showed breakthrough at V = 2 BV, where breakthrough of this paper means 5 % breakthrough.…”

Section: Resultssupporting

confidence: 93%

“…Minor actinides (MA(III): Am(III) and Cm(III)) contained in the HLLW are known to be long-lived and/or heat-generating nuclides, and those are desirable to be removed in order to reduce potential hazard of the vitrified radioactive waste. Japan Atomic Energy Agency (JAEA) has been conducting research and development of the extraction chromatography technology for establishing MA(III) recovery process 1,2 . In this technology, MA(III) is recovered from the HLLW through adsorption/elution reactions between the cations with adsorbent packed in a column.…”

Section: Introductionmentioning

confidence: 99%

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Micro-PIXE analysis on adsorbent of extraction chromatography for MA(III) recovery

et al. 2016

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Japan Atomic Energy Agency (JAEA) has been conducting research and development of MA(III) recovery from high level liquid waste (HLLW) by extraction chromatography technology for reduction in amount and environmental impact of radioactive waste. The behavior of adsorbed cations inside the adsorbent packed in a column is necessary to be evaluated for improvement of the adsorbent or flow-sheet to achieve targeted MA(III) recovery performance. In this paper, micro-PIXE analysis was carried out on the particles sampled from various positions of the column to reveal the behavior of cations inside the packed column with CMPO/SiO2-P adsorbent using RE(III) as simulated elements of MA(III). Simple experiment and data analysis were shown to be effective to reveal inside of the column, and formation and transportation of the adsorption bands were observed for some cations which are extractable by the CMPO extractant. Some part of Zr(IV) and Mo(VI) were found to remain inside the column without distinct transportation even after the elution operation. Those results will contribute to design more practical MA(III) recovery flow-sheet.

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Section: Resultssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Micro-PIXE analysis on adsorbent of extraction chromatography for MA(III) recovery

et al. 2016

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“…Those processes require diluent for organic extractants, and large amount of secondary waste is suspected to be generated. As an alternative to the solvent extraction, the extraction chromatography technology is promising 6) and Japan Atomic Energy Agency has been con-ducting fundamental studies for the implementation [7][8][9][10][11] .…”

Section: Introductionmentioning

confidence: 99%

Influences of Pore and Particle Sizes of CMPO/SiO<sub>2</sub>-P Adsorbent on Extraction Chromatography Process

Watanabe

Sano

Sanda

et al. 2019

J.I.E.

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Extraction chromatography is promising technology for trivalent minor actinides recovery from spent nuclear fuel. In this study, CMPO-impregnated adsorbents with various pore and particle sizes of SiO 2 particles were prepared, and influences of those properties on the adsorption/elution performances were investigated by batch-wise adsorption experiments and column experiments. Only surface of the particle contributed to adsorption when the pore size is too small. In this system, adsorption/elution kinetics was favorable, whereas adsorption capacity was poor. Broadening in the pore size was revealed to enhance diffusion of mobile phase into the particle, and then elution rate was also improved. Since too large pore size might lead weak mechanical strength, refinement in the pore size considering practical operation condition might be required. Large particle showed fine adsorption performance through batch-wise experiments, but formation of channeling or voids inside the packed bed were observed in the column operation. The voids lead poor breakthrough and elution performances. The particle size had to be smaller than 200 μm for the extraction chromatography system though large particle is desirable in the respects of remote handling and adsorption performance.

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“…Some reprocessing plants have already been commercialized for recovering U and Pu from spent nuclear fuel, and numerous studies on partitioning and transmutation of long-lived radioactive nuclides have been conducted globally [1]. In these studies, several researchers have reported the recovery process of long-lived radioactive nuclides by silica-based adsorbents [2][3][4][5][6][7][8][9][10][11][12][13]. Wei et al developed silica-based adsorbents by impregnating an organic extractant into a styrenedivinylbenzene (SDB) copolymer, which is immobilized in porous silica particles [2].…”

Section: Introductionmentioning

confidence: 99%

“…Koma et al assessed the adsorption/elution ability, durability, and after-treatment of several SiO 2 -P adsorbents with different extractants, and the combination of TODGA/SiO 2 -P and R-BTP/SiO 2 -P adsorbents was evaluated as the primary candidate for MA(III) recovery from HLLW [11]. Based on this assessment, MA(III) recovery trials from genuine HLLW were conducted using columns packed with TODGA/SiO 2 -P and R-BTP/SiO 2 -P adsorbents, and the recovery yields of MA(III) and decontamination factors (DF) of other FPs were obtained [12,13]. These previous studies showed that long-lived radioactive nuclides in HLLW could be separated and recovered quantitatively by SiO 2 -P adsorbents impregnated with suitable extractants; however, improvements and optimizations of adsorbents are required for higher recovery yields and DF with less eluent.…”

Section: Introductionmentioning

confidence: 99%

Microanalysis of silica-based adsorbent for effective recovery of radioactive elements

Sano

Watanabe

Matsuura

et al. 2017

Journal of Nuclear Science and Technology

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For effective recovery of radioactive elements by adsorbents using polymer-immobilized silica (SiO 2 -P) supports, the microstructure of SiO 2 -P particles impregnated with octyl(phenyl)-N, Ndiisobutylcarbamoylmethylphosphine oxide as extractants and their change with the crosslinking degree of polymer (CDP) were investigated using scanning transmission X-ray microscopy (STXM) and extended X-ray absorption fine structures (EXAFS) analyses; further, their relation with adsorption/elution behavior was discussed. The results of STXM analysis suggested that the polymer is distributed within several hundred nanometers of the pore surface, and its distributions are spread by the increase of CDP. In addition, the capture of impurity molecules such as H 2 O by polymers with high CDP was indicated. EXAFS analyses showed that the local structure around adsorbed europium ions is similar irrespective of the CDP. The adsorption/elution tests demonstrated that a higher CDP inhibited the elution of adsorbed europium ions from the adsorbent.

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Am, Cm recovery from genuine HLLW by extraction chromatography

Cited by 16 publications

References 10 publications

Micro-PIXE analysis on adsorbent of extraction chromatography for MA(III) recovery

Micro-PIXE analysis on adsorbent of extraction chromatography for MA(III) recovery

Influences of Pore and Particle Sizes of CMPO/SiO<sub>2</sub>-P Adsorbent on Extraction Chromatography Process

Microanalysis of silica-based adsorbent for effective recovery of radioactive elements

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