The Actinide-Lanthanide Separation Concept

Lumetta, Gregg J.; Gelis, Artem V.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

doi:10.1080/07366299.2014.895638

Cited by 94 publications

(72 citation statements)

References 20 publications

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“…In view of this, the current method is a two-cycle approach (16). In contrast, several authors have attempted to develop a single-cycle method for the separation of trivalent actinides from HLLW (17)(18)(19)(20)(21)(22)(23)(24). There are two approaches generally followed in the single-cycle method.…”

Section: Introductionmentioning

confidence: 94%

Studies on the Radiochemical Degradation of Tetraethylhexyl Diglycolamide and Ethylhexylphosphoric Acid inn-Dodecane Solution

Nayak

Chaurasia

Kumaresan

et al. 2014

Separation Science and Technology

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The organic solvent phase composed of N,N,N',N'-tetra-2-ethylhexyl diglycolamide (TEHDGA) and bis(2-ethylhexyl)phosphoric acid (HDEHP) in n-dodecane (n-DD) is regarded as a promising candidate for single-cycle separation of americium (III) from high-level liquid waste. The radiochemical degradation of a solution of TEHDGA + HDEHP/n-DD was investigated by irradiating the solvent to various absorbed dose levels of γ-radiation. The neat extractants or a solution of extractants in n-dodecane were irradiated in the presence and absence of nitric acid. The degree of degradation was assessed by measuring the variation in the extraction behavior of Am(III), Eu(III) and other metal ions in irradiated solvent systems. The distribution ratio of americium and europium decreased with increase of absorbed dose. The presence of n-dodecane enhanced the radiolytic degradation of the solvent; however, the role of nitric acid during degradation was insignificant. The recovery of Am(III) and Eu(III) from the irradiated solvent system was studied. The recovery of Am(III) was quantitative in 3 contacts; however, the separation factor of Eu(III) over Am(III) during stripping decreased marginally with increase of absorbed dose.

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Section: Introductionmentioning

confidence: 94%

Studies on the Radiochemical Degradation of Tetraethylhexyl Diglycolamide and Ethylhexylphosphoric Acid inn-Dodecane Solution

Nayak

Chaurasia

Kumaresan

et al. 2014

Separation Science and Technology

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“…Methods based on solvent extraction have been extensively investigated for the mutual separation of lanthanides and actinides [6][7][8][9][10][11][12]. In contrast to this, the studies on the mutual separation of lanthanides and actinides using solid phase extraction are very limited.…”

Section: Introductionmentioning

confidence: 99%

“…The feed solution for lanthanide-actinide (Ln-An) separation is composed of dilute nitric acid solution (0.1 M to 0.001 M) containing minor actinides and lanthanides [6,7]. It is well recognized that Ln-An separation is a challenging task, since both actinides and lanthanides exist in trivalent oxidation state in the feed solution.…”

Section: Introductionmentioning

confidence: 99%

“…The current method of partitioning involves the separation of trivalent actinides from HLLW together with lanthanides in the first step, followed by mutual separation of lanthanides from actinides or vice-versa in the second step [4,5]. The mutual separation is necessary prior to transmutation, since the lanthanides act as neutron poisons during transmutation of actinides [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…It is well recognized that Ln-An separation is a challenging task, since both actinides and lanthanides exist in trivalent oxidation state in the feed solution. The methods developed so far, for the Ln-An separation usually exploits the finer differences in the chemical behavior of lanthanides and actinides towards various ligands [6][7][8][9][10][11][12][13][14][15][16][17]. According to HSAB concept, the lanthanides are classified as hard acids as compared to the trivalent actinides.…”

Section: Introductionmentioning

confidence: 99%

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Diglycolamic acid anchored on polyamine matrix for the mutual separation of Eu(III) and Am(III)

et al. 2015

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Diglycolamic acid was anchored on a polyamine matrix and the product (PA-DGAH) was characterized by ion-exchange capacity measurement, TG-DTA and FT-IR spectroscopy. The extraction behavior of Am(III) and Eu(III) in PA-DGAH was studied from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of europium, nitric acid and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient ( d ) of Am(III) and Eu(III) was studied.The distribution coefficient decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using PA-DGAH for the separation of Eu(III) from Am(III) with high separation factors.

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