R and D plan for addressing the thermomechanical behavior of lithium ceramic and Beryllium pebble beds in fusion blankets

Several blanket designs based on lithium ceramic and Beryllium pebble beds are currently considered for fusion reactors. The engineering lay-out of these designs can only be confidently done if models are developed that predict the thermal and mechanical behavior of the pebble beds under fusion boundary conditions, in particular because it is impossible to create a large set of in-pile experimental data reflecting such conditions. Modelling of the pebble bed is complicated by the fact that there is a large number of parameters to be considered. The present report gives an account of the parameters determining the thermomechanical pebble bed behavior. It describes the current status of modelling and experiments used to develop models. On this background, the report identifies issues in modelling that need to be addressed by future research, and suggests a strategy for the modelling steps needed to reach a position where the thermomechanical performance of pebble beds in blankets can be predicted with confidence for the complete range of operating conditions. (orig.)Available from TIB Hannover: ZA 5141(6692) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman