This article reports on a new method to elaborate and conduct the safety demonstration phase for Nuclear infrastructures in phase with System Engineering principles. More particularly, this method focus on helping and guiding engineers involved in nuclear safety demonstration into a better assessment considering the increasing complexity and the expectations from the licensing owner who has to accommodate for any new nuclear project. As a first part of this method, this article claims that MBSE coupled to Natural Language Processing (NLP) and Artificial Intelligence (AI) is facilitating the Nuclear safety demonstration process and allowing to early prevent for any issues the project may face during the design, construction, commissioning and exploitation phases.