A: Scientific consensus has long affirmed that the safest method for managing used nuclear fuel is in an engineered repository deep underground. Congress took this into account in enacting the Nuclear Waste Policy Act of 1982, mandating the federal government to begin collecting and disposing of used nuclear fuel from U.S. nuclear power plants in 1998.

The consensus supporting deep geologic disposal has strengthened since then. In 2001, the National Academy of Sciences concluded: “Geologic disposal remains the only scientifically and technically credible long-term solution available.”

Q: Why is Yucca Mountain, Nev., the federal government’s location for a deep geologic repository for the safe storage of used nuclear fuel?

A: The Nuclear Waste Policy Act required an examination of nine sites in six states. Several government agencies and scientific organizations participated in environmental studies and scientific evaluations of these sites. After a 1986 U.S. Department of Energy study ranking Yucca Mountain, Nev., first among these sites, Congress amended the law in 1987 and directed DOE to focus its scientific and environmental investigation entirely on Yucca Mountain.

All aspects of the geological, hydrological and geochemical environment have been studied, along with a detailed evaluation of how conditions might evolve over thousands of years at Yucca Mountain.

In 2002, based on these studies, Congress and the president approved the Yucca Mountain site. In 2004, the U.S. Court of Appeals ruled on several challenges to this approval by repository opponents and fully affirmed the site decision.