Thermal Analysis of Breeder Unit for Helium Cooled Solid Breeder Blanket of Chinese Fusion Engineering Test Reactor

As one of the candidate tritium breeding blankets for Chinese Fusion Engineering Test Reactor, a kind of helium cooled solid tritium breeder blanket was proposed. The blanket uses the pebbles of lithium ceramics (Li4SiO4) and beryllium as tritium breeder and neutron multiplier, respectively. The thermal conditions of breeder unit directly affect the performance of tritium breeding and the safety of blanket. Therefore, thermal analysis of the pebble beds is of vital importance for a reliable blanket design. State steady thermal hydraulic analysis of the breeder unit has been performed, showing that the temperature satisfied the corresponding material temperature limits. State steady thermo-mechanical analysis has also been carried out. The maximum von Mises stress was within the allowable stress. Parametric sensitivity studies have been conducted to investigate the influence of main parameters (e.g. coolant mass flow rate, inlet temperature and pebble bed thermal conductivity) on the temperature distribution of the pebble beds and cooling plates.