This paper presents a multi-criteria evaluation methodology based on Multilevel Flow Model (MFM), a
graphical modeling language and embedding the perspective of sustainable development for energy & environmental
system. A set of indicators reflecting resource utility efficiency, environmental effect, social and economic criteria
according to the different concerns of stakeholder are defined. The graphical assessment process and outcome can
provide help for general people to understand the evaluated object and its variables and to get better decision-making.
Extension Evaluation Method is the first applied in the graphical assessment. The once-through option and
reprocessing option of nuclear fuel cycle system will be examined by using the proposed approach.