Nuclear power systems are not completing system yet. Nuclear systems have a lot of problems for operating, and also we have to solve radioactive waste matters. Therefor nuclear have to stop to build and operate right now. First, if nuclear plants have some problems about operating or natural disaster, it will be a very dangerous situation not only nowadays’ human but also our children and plant-animals. Especially, people have to stop nuclear plant’s operation in dangerous areas such as earthquake areas or typhoon areas. We saw Japan’s Fukushima accident already. Seconds, radioactive waste matters still remain to solve. That means the nuclear system is an unsettled system. So, nuclear plants are still dangerous. We must stop to operate nuclear power plants.