The aim of this paper is to study the optimal nuclear waste burial policy under an uncertainty: the possibility that an accident might occur in the future. The framework is an optimal growth model with pollution disutility. We show, under some conditions on the waste burial policy, that nuclear power may be a long-term solution for the world energy demand. Under uncertainty on the future safety of the buried waste, the social planner will decide to decrease the rate of waste burying, but the evolution of consumption and hence the evolution of the level of buried waste are ambiguous. Depending on some simple conditions on the balanced growth rate of the economy and on the preference parameters of the households, the optimal amount of buried waste may increase, even if there is a risk of accident in the future.