The enhanced fuel management models of the HTR code package (HCP) module SHUFLE

The HTR Code Package (HCP) has been under development since 2010 at Forschungszentrum Jülich and at Aachen University. This HCP combines the capabilities of individual legacy codes developed during the German HTR programme in a highly integrated manner and contains new features. Within the HCP, all aspects related to the fuel management are handled by SHUFLE (Software for Handling Universal Fuel Elements). In principle the module is designed to handle all kinds of fuel elements. The module depicts the pebble flow in such a way, that both the accuracy as well as calculation time constraints given by a multi-physics code package such as the HCP are met. SHUFLE offers two different fuel management models for pebble-bed reactors, the 'flow tube model' and the 'seepage model'. Within this paper, the flow tube model is discussed in detail. Especially aspects such as the development, implementation, application and testing of this model are reviewed.