The design and application of high-temperature in-core furnace equipment for use in a TRIGA research reactor facility is described in this paper. Investigations of the in-pile behavior of high-temperature gas-cooled reactor fuels at temperatures to 1800°C in a variable neutron flux can be conducted using the TRIGA King Furnace (TKF). The TKF consists of an electrically heated graphite tube and an aluminum containment vessel designed to fit an in-core TRIGA fuel element position. The furnace is associated with a gas control and trapping system used to trap contaminants and fission gases from the fuel specimen under investigation. The TRIGA King Furnace Facility (TKFF) has been used for numerous studies, including fission gas and iodine release from various reactor fuels. In addition, neutron-pulsing experiments on pyrolytic-carbon-coated fuel particles have been conducted using the TKFF.