HO and -ray induced oxidative dissolution of stoichiometric UO

Kumagai, Yuta; Fidalgo, A. B.*; Jonsson, M.*

no journal, , 

We have investigated the effect of UO-hyper-stoichiometry on the oxidative dissolution upon HO exposure and by water radiolysis. The oxidative dissolution of UO is anticipated in the concept of geological disposal of spent nuclear fuel and also in the direct contact with coolant water after a severe accident. However, our understanding on the dissolution kinetics has so far not taken the hyper-stoichiometric nature of UO into account. Thus, we have studied the oxidative dissolution of hyper-stoichiometric UO and stoichiometric UO and compared the results. The results show that the UO stoichiometry largely affects the kinetics of oxidative dissolution. The oxidation of stoichiometric UO in water proceeded fast accompanied with low initial U dissolution, but gradually the reaction became slower and U dissolution became more significant.