Description:The management of decommissioning and dismantling of nuclear installations represents an important part of the nuclear- based energy lifecycle, since it has an environmental impact as well as an important influence on the electricity cost and therefore the price for end- users. Bringing new technologies and new solutions into decommissioning methodologies is thus mandatory to improve the quality, cost and delay efficiency of these operations. The purpose of our project is to improve decommissioning management efficiency by developing a decision- support framework dedicated to plan nuclear facility decommissioning operations and to optimize waste evacuation by means of a logistic approach. The target is to create an easy- to- handle tool capable of i predicting waste flows and proposing the best decommissioning logistics scenario and ii managing information during all the steps of the process and following the progress: In this article we present our results from waste nuclear flows simulation during decommissioning process, including discrete- event simulation supported by FLEXSIM 3- D software. This approach was successfully tested and our works confirms its ability to improve this type of industrial process by identifying the critical points of the chain and optimizing it by identifying improvement actions.