AbstractImpurity seeding of tokamak edge plasmas in the form of dust is modeled using the recently coupled DUSTT/UEDGE code. The effects on edge plasma performance due to lithium and carbon dust continuously injected at different poloidal locations in NSTX and ITER are modeled. Modeling demonstrates that dust injection into the edge plasma with rates of the order of several 10 mg · s–1 for NSTX and 1 g · s–1 for ITER can significantly increase radiation power losses leading to substantial reduction of the divertor heat load. The impact of different rates of dust injection on plasma operation and stability is discussed. The simulated edge plasma performance with injected dust is compared with the case of injection of an equivalent amount of dust material in the form of atomic vapor. It is shown that injection of dust in ITER can lead to better assimilation of impurities in the divertor plasma as compared to neutral gas injection (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)