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 inevitable for design, construction and safe operation of DEMOnstration fusion reactors as well as for calibration of data generated from fission reactor and accelerators 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 fulfill the requirements within a realistic time frame. In response to this need, an international design team with members from Europe, Japan, USA and Russia has developed under the auspices of the IEA during a Conceptual Design Activity Phase (1994-96) a suitable and feasible concept for an accelerator driven D-Li stripping source. This IFMIF reference design is based on conservative linac technology and two parallel operating 125-mA, 40-MeV deuteron beams that are focused onto a common liquid lithium target with a beam footprint of 50 mm by 200 mm. The materials testing volume downstream the Li-target is subdivided into different flux regions: The high flux test region (0.5 liter, 20-55 dpa/full power year), the medium flux test region (6 liter, 1-20 dpa/fpy), and low flux test regions (>100 liter, < 1 dpa/fpy). The developed design was the basis fore the present Conceptual Design Evaluation Phase (1997-98) and for subsequent engineering oriented activities. Based on comprehensive neutron transport calculations, an evaluation of the irradiation parameters and the available test 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 developed design includes extensive reliability, availability, maintainability as well as safety studies and is conceived for long-term operation with a total annual facility availability of at least 70%. (author)