Surface electrochemistry of SIMFUEL in dilute alkaline hydrogen peroxide solutions

Since nuclear waste containers are expected to survive for considerable periods of time under permanent waste disposal conditions, the gamma/beta radiation fields associated with the fuel waste form will have decayed to insignificant levels before container failure occurs and the fuel comes in contact with groundwater. Consequently, only the alpha radiolysis of water has the potential to produce the oxidants required to drive fuel dissolution in the long term. Since the primary product of alpha radiolysis is hydrogen peroxide, an understanding of the behaviour of peroxide on fuel surfaces is essential to the development of models to predict fuel behaviour under permanent disposal conditions. The chemistry/electrochemistry of peroxide is complicated by its ability to decompose to produce a second, but less aggressive oxidant, oxygen. The kinetics of these processes are being studied electrochemically. The primary goal is to determine kinetic parameters that can be used in fuel dissolution models. (author)