Electrochemical behavior of plutonium in nitric acid media

Abstract : The first step of the spent nuclear fuel reprocessing is a dissolution of actinides and fission products in hot nitric acid at high concentration. Among all these species, the knowledge of redox plutonium equilibria with discerning between their oxidation states is essential to understand and depended on many chemical conditions. Nevertheless, the knowledge of speciation in this media is a challenge especially for a better understanding of corrosion mechanism in the dissolution medium. Thus this paper proposes to determine the electrochemical behaviour of plutonium and especially the Pu(IV)/Pu(III), Pu(VI)/Pu(V) and Pu(V)/Pu(IV) redox couple in nitric acid media and acquire thermodynamic and kinetic constants at higher temperatures than 25C and higher nitric concentration than 1 mol L−1.