The article is devoted to the understanding of nuclear safety in legal terms under the modern conditions. The article gives an overview of the Fukushima Daiichi accident and its impact on the international legal framework for nuclear security and Japanese society. The article also shows the influence of International Atomic Energy Agency Action Plan on the process of creating a global nuclear safety regime, and its role in enhancing international safety standards. The author supports the idea that nuclear safety combines two main elements and gives their definitions. One of these disputable instruments is the International Atomic Energy Agency Safety Standards intended to protect people and the environment against harmful effects of ionizing radiation. Does the international society have appropriate legal instruments that could be considered as safety fundamentals and legally binding standards internationally recognized? This remains one of the main post-Fukushima questions.