*(tentative abstract to give a first idea about content; might be subject to change)* In this contribution, we report on progress with simulations of MGI scenarios in AUG using the toolset `ASTRA-STRAHL`. Recently, improved RE generation (fluid) models [^1][^2] have been implemented as a fortran module in `ASTRA` and successfully benchmarked against L. Hesslow's publications [^1][^2]. Applying these models, the RE behavior in Ar MGI discharges is reproduced by `ASTRA`. Here, correct simulation of impurity penetration is an important prerequisite. The relevance of different impurity transport channels is discussed in this context. Simulations of the RE response to varying impurity amounts and types (D, Ne, Ar, Kr) will be presented and compared to experimental observations (*depending on further progress*). [^1]: L. Hesslow, O. Embreus, O. Vallhagen and T. Fülöp. Influence of massive material injection on avalanche runaway generation during tokamak disruptions. *Nucl. Fusion* **59**, 084004 (2019). [^2]: L. Hesslow, L. Unnerfelt, O. Vallhagen, O. Embreus, M. Hoppe, G. Papp and T. Fülöp. Evaluation of the Dreicer runaway growth rate in the presence of high-$Z$ impurities using a neural network. Submitted to *J. Plasma. Phys.*