For Japan, the situation has become extremely difficult since counter-measures to deal with the nuclear accident had to be carried out along with dealing with the broader disaster caused by earthquake and the tsunami. In terms of damage, the Tohoku earthquake and the tsunami have caused the most fatalities and the largest economic loss ever from an earthquake and/or tsunami. The impact of this natural disaster is present not only in Japan but world-wide. The state of affairs in the global energy sector is affected by the consequences which may be lasting for decades. These effects are subject of this article dealing not with the nuclear accident at Fukushima Daiichi NPPs itself, but rather with the world-wide consequences and after effect on nuclear energy development. This includes: environmental damages, socio-economic effects, actions of safety authorities, extended protective measures against external events, the impact on global nuclear energy, triggered nuclear phase-outs and changes in new build plans as well as the sustainability of energy mix itself and an outlook.