The gas-cooled fast reactor (GFR) is one of six concepts for the Generation-IV nuclear energy system. The fuel for the GFR requires both a high heavy metal loading and the ability to withstand temperatures up to 1600°C during a loss of coolant accident. ZrC is among the few potential refractory ceramic materials with necessary properties to be considered as matrix materials for a dispersed carbide fuel. The radiation response of ZrC to high dose and temperature is a critical research need. This work investigated the microstructure of ZrC irradiated with 1 MeV Kr ions to doses of 10 and 30 dpa at 27°C and 10 and 70 dpa at 800°C with a damage rate approximately 3.0 × 10-3 dpa/s. No radiation-induced amorphization was found. A lattice expansion of approximately 7 % was observed for ZrC irradiated to 70 dpa at 800°C.