Improved Helium Cooled Pebble Bed Blanket

Abstract

In the European Fusion Programme of 1999 preparatory work (Preparation of a Power Plant Conceptual Study Availability, PPA) has been carried out for a fusion power plant study that is planned to start in 2000. This study will focus on the commercial attractiveness of a fusion plant, particularly achievable power level, net efficiency and availability. Part of the activity at the Forschungszentrum Karlsruhe has been the further development of the Helium Cooled Pebble Bed (HCPB) blanket for DEMO as “Improved HCPB” (Subtask PPA 2.3). The modified concept allows for the height of breeder pebble beds to be reduced and thus for larger power densities to be accommodated. Also, mono-disperse Beryllium pebble beds can be used. The net electric efficiency of the blanket was raised by almost 7 points to about 37% due to increased coolant temperature gain, reduction of pressure losses in the blanket and enhanced energy conversion in the proposed steam process. The good availability of the DEMO-HCPB that was shown in earlier studies is expected to carry over to the I-HCPB.