Availability of the European test blanket systems and their influence on ITER

Two blanket concepts are under development in the European Blanket Project. The first concept uses liquid Pb17Li as breeder and neutron multiplier and water as coolant (WCLL). The second concept uses lithium ceramic as breeder, beryllium as neutron multiplier and helium as coolant (HCPB). The two concepts represent design alternatives for the DEMO blanket and will be tested independently in ITER. The unavailabilities of the Test Blanket Modules (TBMs) including the Test Blanket Auxiliary Systems (TBAS) are assessed and the influence on the availability of ITER is analysed. Reference systems in ITER are the cooling systems for the first wall, the divertor, the limiter and the vacuum vessel. (authors)