Besides the Generation IV International Forum (GIF), which focus on the medium-long term (> 2040), some major inputs from the international nuclear community are defining a new framework to fit with the short - medium term. Among them, the European Technology Platform on Sustainable Nuclear Energy (SNE-TP) and its European Strategic Research Agenda (SRA) propose a vision for the short, medium and long-term where the sodium technology plays a key role. Anticipating these guidelines, under the aegis of the 6th framework programme, in 2007, the Specific Support Action (SSA) named ¿Roadmap for a European Innovative Sodium cooled FAst Reactor ¿ EISOFAR¿ aimed enabling the European Community to define its specific R&D strategic objectives for a fourth generation European Sodium cooled Fast Reactor (ESFR). The corresponding Roadmap has the ambition to be a key component of the European SRA which address the needs for research and development as well as for technology demonstration (at the pre-competitive stage). The large integrated Collaborative Project on European Sodium Fast Reactor (CP ESFR), described within the report, follows logically this action further identifying, organizing and implementing a significant part of the needed R&D effort. The project is proposed to be realized under the aegis of the 7th FP to answer the EURATOM Work programme 2008 for the topic Innovative Reactor Systems (cf. § Fission-2008-2.2.1) which is identified under the Area II.2.2.2 - Advanced Nuclear Systems.