An improved European helium cooled pebble bed blanket

The Helium Cooled Pebble Bed (HCPB) blanket is one of the two European breeding blanket concepts for DEMO. In the framework of selecting reference blankets for the European Flower Plant Conceptual Study (PPCS) performance limits of the HCPB concept have been explored. This paper shows the improved, moderate-technological-extrapolation HCPB blanket design including recent changes to the breeding zone that counteract a recuperator effect in the cooling plates. It highlights the attractive features of the design, like single-size Beryllium beds, large admissible neutron wall loads (NWL) and much improved electrical efficiency. In addition to two reference blanket cases proposed in the study, a third blanket based on the small NWL in the PPCS reactor is put forward. Finally, steam cycle efficiencies calculated with an up-to-date power plant code correct previous values for the improved HCPB blanket upwards by about 2%. (C) 2001 Elsevier Science B.V. All rights reserved.