During normal operation of a pebble bed type high temperature gas-cooled reactor (HTGR), significant amounts of graphite dust were generated due to the friction between the fuel elements and associated structural components. The graphite dust deposited on the primary circuit pipelines, and some fission products released from the fuel elements can adsorb on the graphite dust, causing an important accident source term—radioactive graphite dust. This study provides a review of the source term calculation codes used for modeling the behavior of radioactive substances in the primary circuit of HTGRs, and analyzes the mechanisms and experimental foundations underlying these codes, focusing on how they describe the interaction between fission products and graphite dust. Moreover, this study summaries the generation, distribution, morphological characteristics of graphite dust and adsorption of radioactive nuclides on graphite dust in HTGRs and research on simulating the interaction between radioactive nuclides and graphite materials using density functional theory (DFT). It indicated that it is necessary to attempt to combine the DFT results with the source term calculation programs for HTGRs. This study can serve as a reference for the research on the interaction between fission products and graphite dust, and promote the advancement of source term studies in HTGRs.