Electrochemistry of uranium in molten LiF-CaF2

Christophe Nourry (1) , Pavel Soucek (1) , Laurent Massot (2) , Rikard Malmbeck (1) , Pierre Chamelot (2) , Jean-Paul Glatz (1)

1 ITU - JRC Institute for Transuranium Elements [Karlsruhe]
2 LGC - Laboratoire de Génie Chimique

This article is focused on the electrochemical behaviour of U ions in molten LiF-CaF2 (79-21 wt.%) eutectic. On aWelectrode, U(III) is reduced in one step to U metal and U(III) can be also oxidised to U(IV). Both systems were studied by cyclic and square wave voltammetry. Reversibility of both systems for both techniques was verified and number of exchanged electrons was determined, as well as diffusion coefficients for U(III) and U(IV). The results are in a good agreement with previous studies. On a Ni electrode,the depolarisation effect due to intermetallic compounds formation was observed. Electrorefining of U metal in a melt containing U and Gd ions was carried out using a reactive Ni electrode with promising results.

Mots clés: Uranium; Fluorides; LiF-CaF2; Electrochemistry

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

Christophe Nourry, Pavel Soucek, Laurent Massot, Rikard Malmbeck, Pierre Chamelot, et al.. Electrochemistry of uranium in molten LiF-CaF2. Journal of Nuclear Materials, 2012, vol. 430, pp. 58-63. ⟨10.1016/j.jnucmat.2012.06.028⟩. ⟨hal-00831234⟩