Oxidation State Shift of Uranium during U(III) Synthesis with Cd(II) and Bi(III) in LiCl–KCl Melt

Bae, Sang-Eun; Cho, Young-Hwan; Park, Yong Joon; Ahn, Hong Joo; Song, Kyuseok

doi:10.1149/1.3465303

Cited by 20 publications

(17 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The red curve in Fig. 8 is a cyclic voltammogram recorded one hour after the addition of BiCl 3 which shows the presence of an additional peak at 0.15 V (vs Ag/AgCl), which is concordant with the Bi/Bi 3+ couple in LiCl–KCl eutectic [ 23 , 33 ]. The boiling point of BiCl 3 (447 °C) is lower than the temperature employed in these studies so it was important to verify the stability of Bi(III) in the melt.…”

Section: Resultsmentioning

confidence: 94%

“…A similar method has been used to produce U(III) in fluoride melts [ 22 ]. This work presented here extensively explores the reaction of U metal with BiCl 3 in LiCl–KCl eutectic at 450 °C using electrochemical and spectroscopic techniques to probe the redox mechanistic behavior of this reaction, building upon previous work by Bae et al [ 23 ], in order to ensure the control and efficiency of this key reaction for the production of U(III) as the research of actinide behavior in molten salt systems expands with advancing nuclear technologies.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Preparation of uranium(III) in a molten chloride salt: a redox mechanistic study

Lambert

Kerry

Sharrad

2018

J Radioanal Nucl Chem

View full text Add to dashboard Cite

The most advanced methodology for the pyroprocessing of spent nuclear fuel is the electrorefining of uranium metal in LiCl–KCl eutectic, in which uranium is solubilized as U(III). The production of U(III) in LiCl–KCl eutectic by the chlorination of uranium metal using BiCl3 has been performed for research purposes. In this work, this reaction was studied in-situ by visual observation, electronic absorption spectroscopy and electrochemistry at 450 °C. The most likely mechanism has been determined to involve the initial direct oxidation of uranium metal by Bi(III) to U(IV). The dissolved U(IV) then reacts with unreacted uranium metal to form U(III).

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Preparation of uranium(III) in a molten chloride salt: a redox mechanistic study

Lambert

Kerry

Sharrad

2018

J Radioanal Nucl Chem

View full text Add to dashboard Cite

show abstract

“…19,22,26,27 Figure 3 shows the electronic absorption spectra of LiCl-KCl eutectic melts containing UCl 3 , NdCl 3 , and CeCl 3 . Prior to Li 2 O addition, U 3+ and Ce 3+ exhibit their characteristic f-d transitions at 400-700 nm and 250-350 nm, respectively.…”

Section: Resultsmentioning

confidence: 99%

Electrochemical and Spectroscopic Monitoring of Interactions of Oxide Ion with U (III) and Ln (III) (Ln = Nd, Ce, and La) in LiCl-KCl Melts

Choi

Bae

Park

2017

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

Using cyclic voltammetry and UV-vis absorption spectroscopic methods, we studied the precipitation reactions of trivalent uranium and lanthanides (Nd, Ce, and La) with the oxide ion in LiCl-KCl molten salts, which are likely side reactions during the electrorefining process for nuclear fuel treatment. The in situ electrochemical and spectroscopic monitoring demonstrated that U 3+ consumed O 2− with the mole ratio of 2:1, whereas the lanthanide ions reacted with O 2− with the mole ratio of 1:1. Raman spectroscopy and X-ray diffraction were also employed to analyze the precipitates, confirming that U 3+ was precipitated and oxidized into UO 2 , while the trivalent lanthanide ions formed oxychlorides (LnOCl). As a preliminary study of actinide co-precipitation, we also electrochemically monitored the precipitation reactions in a mixed melt containing uranium and lanthanides, demonstrating a higher reactivity of the former with the oxide ion in LiCl-KCl. Understanding the chemical reactions in chloride-based molten salts at high temperatures is of fundamental importance for developing pyroprocessing technologies, which have been extensively examined over the last 30 years as a promising solution for accumulated spent nuclear fuel. [1][2][3][4] In particular, the electrochemical behaviors of actinides and lanthanides in LiCl-KCl melts have been widely studied to explain the fundamental electrochemical reactions in the electrorefining process, which partitions reusable metals and highly radioactive fission products.5-7 However, before the commercialization of this technology, it is necessary to obtain comprehensive insight of the molten salt chemistry of trace elements dissolved from the spent nuclear fuel, and the additives and/or impurities that enter during the process. 8,9 Li 2 O is a critical ingredient for the electrochemical reduction of spent oxide fuel. It affords O 2− ions that should diffuse to the anode at the beginning of the reduction process, and controls the O 2− concentration in the LiCl melt to prevent the Pt cathode from dissolving. 3 However, a trace amount of Li 2 O likely remains in the reduced fuel, even after distilling out the molten salt at the end of the oxide reduction process, and can enter the next process. During the electrorefining process, the oxide ion may react with trivalent actinide and lanthanide ions in the LiCl-KCl eutectic melt, affording insoluble oxides and oxychlorides 10,11 which contaminate the salt and reduce the purity and yields of recovered uranium. In addition, unreduced lanthanide oxides in the metal fuel feed play the role of oxo-donor in the LiClKCl melt.12 Therefore, knowledge of the reactions between the actinide/lanthanide ions and the oxide ion in the molten salt could lead to improvement in the electrorefining technology. Several research groups have studied such reactions by potentiometric titration of the oxide ion in the melt and product characterization, in order to estimate the thermodynamic properties for oxide reduction 10,12-15 and to partition lanthan...

show abstract

“…UCl 3 in molten salt was prepared using the previously reported procedure. 15 An electrochemical reaction vessel was made out of a quartz tube (350 mm in length, 20 mm in outer diameter, and 2 mm in wall thickness) using a glass blowing technique. GC or W electrodes were used as working or counter electrodes, as described elsewhere.…”

Section: Methodsmentioning

confidence: 99%

Electrochemical Reactions of Uranium Trichloride on a Graphene Surface in LiCl-KCl Molten Salt

et al. 2014

Self Cite

View full text Add to dashboard Cite

The electrochemcal reactions of uranium trichloride on the surfaces of dimensionally very dissimilar carbon-based materials such as glassy carbon (GC) and graphene in LiCl-KCl eutectic melt were investigated using cyclic voltammetry (CV) and scanning electron microscopy (SEM). The cathodic scanning of CV displayed that the Li intercalation reaction into the GC electrode governs at the potential of approximately −1.45 V vs. Ag|Ag + where the electrodeposition reaction of uranium may occur. On the other hand, the graphene electrode presented electrodeposition current of the uranium without interference at −1.45 V vs. Ag|Ag + because the Li intercalation reaction was extensively diminished on the very thin graphene film. In addition, it was successful to measure the electrodeposition current of gadolinium at more positive than −2.1 V without the interference of the Li intercalation into the graphene substrate. Consequently, the significant reduction of the Li intercalation reaction on the nanometer thick carbon electrode extensively expands the electrochemical potential window of the carbon-based electrode with respect to the bulk carbon electrode in LiCl-KCl melt, emphasizing that the graphene has a great potential as a cathode electrode in high temperature molten salt electrolytes.

show abstract

Oxidation State Shift of Uranium during U(III) Synthesis with Cd(II) and Bi(III) in LiCl–KCl Melt

Cited by 20 publications

References 12 publications

Preparation of uranium(III) in a molten chloride salt: a redox mechanistic study

Preparation of uranium(III) in a molten chloride salt: a redox mechanistic study

Electrochemical and Spectroscopic Monitoring of Interactions of Oxide Ion with U (III) and Ln (III) (Ln = Nd, Ce, and La) in LiCl-KCl Melts

Electrochemical Reactions of Uranium Trichloride on a Graphene Surface in LiCl-KCl Molten Salt

Contact Info

Product

Resources

About