To achieve closed nuclear fuel cycle and sustainable development of nuclear energy, efficient pyroprocessing of spent fuel becomes one of the major concerns in Generation IV nuclear energy ^[1]. Molten salt based electrolysis is a promising method in future pyroprocessing technology. As neutron poison, lanthanides are the typical detrimental elements that encumber the realization of the so-called partitioning & transmutation (P&T) strategy, and thus must be separated from actinides ^[2]. Therefore, investigating the electrochemical properties of actinides and lanthanides is of pivotal importance. In fact, in light of the chemical similarity of trivalent actinides and lanthanides, the chemistry of actinides can be revealed somewhat through exploring the lanthanide elements which are more readily obtained ^{[3, 4]}.

In this work, it was found that the reduction potentials of Cu(Ni, Al, Zn)-rich Cu(Ni, Al, Zn)-Ln alloys manifest an evident “Bimodal Effect”. Hume-Rothery rules pointed out that the main factors affecting the formation of alloy solid solution of two metal elements are: 1) the difference of the atomic radius of the solvent and the solute metals, and 2) the electronegativity difference between the solvent and the solute metals. By fitting the data of reduction potentials, differences of the atomic radii and electronegativity differences, a formula was built up, which provides a useful and reliable approach for predicting related important reduction potentials of actinide alloys. The result of multiple linear regression analysis (Fig. 1) indicated that the good reliability of forecast and goodness of fit.

Acknowledgments

This paper is funded by the International Exchange Program of Harbin Engineering University for Innovation-oriented Talents Cultivation.

References

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