Vincent Chapurlat

Optimizing nuclear installation decommissioning and dismantling operations is an ongoing quest. Faced with the complexity of this activity, Model Based System Engineering promotes relevant principles and modeling techniques. It motivated the definition of a functional generic pattern model of the waste package production line and the decommissioning of the facility. It proposes a global and generic functional architecture of such a system aiming to reduce the level of the pollutant. This pattern is coupled with a process of logistics. Six functions are combined to define this functional pattern. The application of this pattern model to a case of waste recovery in a pit shows the relevance of the model-based system engineering approach, reducing the weight of the history in the development of scenarios by optimizing the control means for nuclear safety and product quality.

Nuclear infrastructure development projects are increasing in complexity, involving numerous and various stakeholders. Highly constrained, they are often subject to many hazards. This has an impact on the number of desired design alternatives generated throughout the facility life cycle and their evolving assessment. In order to secure the delivery of such projects, the Évaluation for Critical Infrastructures Model‐based system Engineering (EVA‐CIME) method is proposed to implement and operate the architecture evaluation at the scales both of an organization and of projects. This article presents the elements justifying the formalization of such method and the obstacles to overcome. This method must be technically and organizationally usable by the different actors of a nuclear infrastructure development project. It is composed of 5 elements: concepts; languages; operational approach; tools and repository of knowledge and expertise. The good orchestration of these different components allows to set up an environment within the organization to carry out effective architecture evaluations with the aim of helping the architects to choose between the alternatives that they will imagine from the beginning of the project.

Commissioning is considered as a critical phase in the delivery of a Nuclear Facility (NF) as it is the first stage in the authorization of the NF to be exploited. Most of the nuclear projects start to overrun costs during commissioning mainly since this phase is not addressed properly and is affected by many issues from previous phases (Design, Procurement, and Construction). This article proposes a general methodology to prepare and realize the commissioning activities. Using models to do so improves communication and removes ambiguities between stakeholders. It also formalizes and clarifies the commissioning organization and activities prior to any implementation. It also allows for capitalizing and sharing the experience from previous projects, by drawing references models and good practices patterns. The so-called Model Based commissioning method is elaborated around concepts, languages, processes, tools, and patterns inspired from Model Based System Engineering (MBSE) principles and practices. The theoretical foundations will be supported by results from nuclear facilities demonstrating the added value.

Dismantling and Decommissioning (D&D) of nuclear facilities involves complex operations, requiring various activities’ many stakeholders to collaborate, and must address numerous significant constraints. The CEA (French Alternative Energies and Atomic Energy Commission), is conducting research to better pilot these operations, reduce their costs and timeframes, and improve overall performance. However, many issues remain, leading to studying and implementing, in the form of a method with appropriate tools, systemic principles and complex project and systems engineering. This method first formalizes and specifies the entire requirement set to consider. Second, based on these requirements, the method will enable the project team to structure, check, and demonstrate the project's coherence and feasibility from both the technological and organizational viewpoints. Lastly, the method should permit a constant D&D strategy and product management re‐evaluation, depending on the possible D&D project evolution. Developing demonstration software aims to provide the functionalities requested for the design, and future enterprise software implementation and maintenance, which should provide a complete D&D project Digital Mock‐Up being interoperable and connected to the tools and databases of the stakeholders’ information systems.