The 2018 edition of the RCC-MRx Code  will be issued by the end of the 2018, in French and English versions by AFCEN (Association Française pour les règles de Conception et de Construction des Matériels des Chaudières Electro-nucléaires). This Code set up design and construction rules of research reactor components (coming from the RCC-MX 2008 code developed within the context of the Jules Horowitz Reactor project), and to components operating at high temperature and to the Vacuum Vessel of ITER (coming from the RCC-MR 2007).
The extension of the scope of the code to innovative systems such as fusion reactors leads to revisit the background of the code to define the requirements to introduce a new process or a new material.
The developed methodology has been applied to the introduction of the Fe–9%Cr–1%W–TaV steel (Eurofer), today in the Probationary Phase Rules of RCC-MRx. It was the first time to introduce a “new” material into the code, new in the sense of non-existing in any current standardization. This process, still in progress, highlights the need to have a minimum of information on the expectation of the code regarding the material data.
This paper describes the different steps of the introduction of the Eurofer in the RCC-MRx code as well as the tools developed to facilitate the process.