Suitability and feasibility of the International Fusion Materials Irradiation Facility (IFMIF) for fusion materials studies

There is a global consensus among materials scientists and engineers that the qualification of materials in an appropriate test environment is indispensable for the design, construction and safe operation of demonstration fusion reactors as well as for the calibration of data generated from fission reactor and accelerator irradiations. In an evaluation process based on a series of technical workshops it was concluded that an accelerator driven D-Li stripping source would be the best choice to fulfil the requirements within a realistic time frame. In response to this need, an international design team with members from the European Union, Japan, the United States of America and the Russian Federation has developed, under the auspices of the International Energy Agency during a conceptual design activity phase (1994-1996), a suitable and feasible concept for an accelerator driven D-Li stripping source. This reference design for the International Fusion Materials Irradiation Facility (IFMIF) is based on conservative linac technology and two parallel operating 125 mA, 40 MeV deuteron beams that are focused onto a common liquid Li target with a beam footprint of 50 mm by 200 mm. The materials testing volume behind the Li target is subdivided into different flux regions: the high flux test region (0.5 L, 20-55 dpa/full power year), the medium flux test region (6 L, 1-20 dpa/full power year), and the low flux test region ( > 100 L, < 1 dpa/full power year). The design developed was the basis for the conceptual design evaluation phase (1997-1998) and for subsequent engineering oriented activities. On the basis of comprehensive neutron transport calculations, an evaluation of the irradiation parameters and the available testing volumes has shown that the users' requirements can be fulfilled. Major engineering efforts have been undertaken to establish an IFMIF design that is based on available and already proven technologies. The design developed is based on extensive reliability, availability, maintainability and safety studies and is conceived for long term operation with a total annual facility availability of at least 70%. (author)