High-level nuclear waste -- one of the nation's most hazardous substances -- is accumulating at 80 sites in 35 states. The waste is supposed to be disposed of in a geologic repository at Yucca Mountain, about 100 miles northwest of Las Vegas, NV. However, the repository is more than a decade behind schedule, and the nuclear waste generally remains at the commercial nuclear reactor sites and DoE sites where it was generated. This report examines the key attributes, challenges, and costs of the Yucca Mountain repository and the two principal alternatives to a repository that nuclear waste management experts identified: storing the nuclear waste at two centralized locations and continuing to store the waste on site where it was generated. Ill.