Beryllium R&D for fusion applications

Beryllium is one of the primary candidates as both plasma-facing material ( PFM) and neutron multiplier in the next-step fusion reactors. Both sintered -product blocks and pebbles are considered in fusion reactor designs. Beryl lium evaporated on carbon tiles has also been used in Joint European Torus (JET) and may be considered for other designs. Future efforts are directed toward the pebble form of beryllium. Research and evaluations of data are u nderway to determine the most attractive material processing approaches in terms of fabrication cost and quality; technical issues associated with hea t transfer; thermal, mechanical and irradiation stability; safety and triti um release. Beryllium plasma-facing components will require periodic repair or replacement, therefore disposal or recycling of activated and tritiated beryllinm will also be a concern. Beryllium as a component of the molten s alt, Flibe is also being considered in novel approaches to the plasma-struc ture interface. This paper deals with the main issues related to the use of Be in a fusion reactor as both neutron multiplier and first wall material. These issues include potential reactions with steam during accidents and t he health and environmental aspects of its use, reprocessing and reuse, or disposal. (C) 2000 Elsevier Science B.V. All rights reserved.