[en] The final goal of decommissioning of Nuclear Power Plant is to remove or to isolate the radioactivity existing at the nuclear facilities which are confronted with termination of operation. The regulatory guidance and technologies of decommissioning have been developed strategically in some advanced countries. They have already stepped into the application stage from the research and development stage. The contents and the scope of this study is as follows, preparation of standard evaluation plan and establishment of standard safety evaluation system for D and D