The coordination action SITEX-II aims at implementing in practice the activities along with the interaction modes issued by the FP7 program SITEX project (2012-2013), in view of developing an Expertise function network. This network is expected to ensure a sustainable capability of developing and coordinating joint and harmonized activities related to the independent technical expertise in the field of safety of deep geological disposal of radioactive waste. SITEX-II tasks include: – the definition of the Strategic Research Agenda (SRA) based on the common R&D orientations defined by SITEX (2012-2013), the definition of the ToR for the implementation of specific topics from the SRA, and the interaction with IGD-TP and other external entities mandated to implement research on radioactive waste disposal regarding the potential setting up of an European Joint Programming on radioactive waste disposal; – the production of a guidance on the technical review of the safety case at its different phases of development, fostering a common understanding on the interpretation and proper implementation of safety requirements for developing, operating and closing a geological repository and on the verification of compliance with these requirements; – the development of a training module for generalist experts involved in the safety case review process, including the implementation a pilot training session; – the commitment of CS in the definition of the SRA mentioned above, considering the expectations and technical questions to be considered when developing R&D for the purpose of Expertise function. Close interactions between experts conducting the review work will allow enhancing the safety culture of CS and more globally, proposing governance patterns with CS in the framework of geological disposal; – the preparation of the “administrative” framework for a sustainable network, by addressing the legal, organisational and management aspects.