Voltammetric Investigations of the Redox Behaviour and the Speciation of Plutonium in Concentrated Electrolyte Solutions with Respect to ILW Repositories

Abstract

Plutonium / Voltammetry / Formation constants of plutonium chlorocomplexes / Radioactive waste disposal in salt diapirs SummaryThe formation constants of chlorocomplexes of Pu(IV) were determined in saturated NaCl solutions, by use of Differential Pulse Voltammetry (DPV) with a rotating disk electrode, for modelling safety aspects of radioactive waste repositories located in salt diapirs. The results obtained are: lg/T 0Xl =0.13±0.02; lg*ox2= -1.6s ±0.2; lg.K"3= -0.15±0.2. The special electrochemical equations necessary for describing the half-wave potential vs. chloride concentration and for applying a new iteration process were derived under the boundary conditions present. The equations and the complexing influence of hydrolysis are discussed in detail.

The Simulation of Differential Pulse Voltammetry

“…This can be used to work out the current using equation (13). The currents prior to and at the end of each pulse are then subtracted from each other to produce the simulated voltammogram.…”