The proposed book covers three themes: what was the reactor situation globally, pre-Fukushima, what happened at Fukushima, and how can lessons learned from Fukushima be implemented to identify new perspectives on technology, safety and economics of reactor design, to ensure that a disaster like Fukushima will not recur. The book aims at delineating a nuclear system which has very little chance of failing, and if it fails, to minimize the adverse consequences for man and environment.