Thermal Analyses of the Breeder Unit of the Helium Cooled Pebble Bed Test Blanket Module

This paper deals with thermal analyses of the breeder unit of the Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM). This TBM will be tested in the nuclear fusion reactor ITER. Parametric sensitivity studies have been carried out in order to determine the influence of the main input data on the temperature distribution in the different materials of the breeder unit. The sensitivity studies showed that the maximum temperature values of Lithium orthosilicate (OSI) and Beryllium strongly depend on the thermal conductivity. Moreover the analyses indicated the need of further optimizations of the BU geometry in order to achieve higher average temperatures to assure lower tritium residence time and lower inventory in the Breeder Zone.