The inhibiting effects of hydrogen on the corrosion of uranium dioxide under nuclear waste disposal conditions

A number of electrochemical experiments were employed to investigate the effects of hydrogen on the corrosion of UO2 under nuclear waste disposal conditions. A combination of corrosion potential (E-CORR) measurements and cyclic voltammetry have indicated that dissolved hydrogen can polarize the UO2 surface to reducing potentials; i.e., to E-CORR values more negative then those observed tinder anoxic (argon-purged) conditions. A comparison of the behaviours of SIMFUEL specimens with and without incorporated noble metal F-particles indicates that these particles may act as catalytic electrodes for H-2 oxidation, H-2 <-> 2e(-) + 2H(+). It is the galvanic coupling of these particles to the UO2 matrix which suppresses the fuel corrosion potential. (c) 2005 Elsevier B.V. All rights reserved.