In 2013 registered nuclear power consumption in several countries, including France, Germany, and other OECD members, declined. In this paper, we focus on nuclear consumption leaders and explore, through diffusion models, whether and to what extent Fukushima accident had a short-term effect on these countries' consumption dynamics. Safety checks, performed after the accident caused temporary shutdowns in production but not all of them were significant enough to modify nuclear energy evolution. Then, we compared the evolutionary behavior estimated through the entire time series and that obtained by excluding the last three observations (2011–2013): what would the forecasts have been before Fukushima? Significant short-term effects were identified in 2011–2013 at the global level, for France, and South Korea, while they have not been identified for the US, Germany, and Russia. About the medium-term evolution predicted by the models, we identified countries with declining consumption (the US, France, Germany and South Korea) and with increasing consumption (China, Russia, and Canada). At the global level a declining trend is predicted.