A deep geologic disposal system for the spent fuels from nuclear power plants has been developed since this program was launched in 1997 in Korea. In this paper, the concept of a Korean reference high-level waste (HLW) vertical disposal system (KRS-V1) is described. Though no site for the underground repository has yet been specified in Korea, a generic site with a granitic rock is considered for a reference spent fuel repository design. The depth of the repository is assumed to be 500 m. The repository consists of a disposal area, a controlled area, and an uncontrolled area. The disposal area consists of disposal tunnels, panel tunnels, and a central tunnel. In the controlled area and the uncontrolled area, there are technical rooms and tunnels and/or shafts to connect them to the ground level, respectively. The repository will be excavated, operated, and backfilled in several phases including an underground research laboratory (URL) phase. The result of this concept development will be used for an evaluation of its feasibility, analyses of its long-term safety, information for public communication, and a cost estimation, among others.