Tritium Release Characteristics of Neutron-Irradiated Reference Beryllium Pebbles for the Helium Cooled Pebble Bed (HCPB) Blanket

Beryllium pebble beds are considered as a neutron multiplier of the European Helium Cooled Pebble Bed (HCPB) tritium breeding blanket for future fusion power reactors. The tritium accumulated in the beryllium pebbles may cause operational and environmental problems, and therefore tritium release properties of the beryllium pebbles are an important factor for safe operation of the fusion reactor. Under the operating conditions of the HCPB, the beryllium pebbles will be under action of high neutron flux (10 n m s), high temperature (up to 920 K) and intense magnetic field (up to 7-10 T) [1].