Construction of an electrode for irradiated UO2 fuel and preliminary results concerning its use in aqueous solutions

An electrode and reaction vessel design is presented that is suitable for use in hot cells. The electrode can be constructed of irradiated materials such as highly active glasses or irradiated fuels and can be inserted in the vessel using manipulators. The first tests of the experimental set-up using dummy cells are given along with the first results of the irradiated UO2 electrodes. These are compared with similar tests using natural UO2 in 3% Na2CO3 solutions. Optical microscopy and SEM was performed on the electrodes. The porosity and high resistivity of the natural UO2 material makes it very susceptible to pitting corrosion at defects or grain boundaries. Irradiated UO2 has a much lower resistivity but is still susceptible to pitting, especially as there are more defects and secondary phases present. The overall corrosion rate is higher for the irradiated UO2.