Spectroelectrochemical study of neptunium in molten LiCl-KCl eutectic

Neptunium behaviour in an LiCl-KCl eutectic melt at 723 K was studied using spectroelectrochemistry. Cathodic reduction of neptunium(IV)-containing melts led to the formation of Np(III) ions and then Np metal. Electronic absorption spectra of Np(IV) and Np(III) chloro species in LiCl-KCl melt were recorded and resolved into inidividual Gaussian bands. The nature of neptunium complex ions in the melt is discussed.