President Bush has signed a bill formally designating Yucca Mountain as the nation's central repository for nuclear waste.
He says 20 years of study show it'll be safe to bury thousands of tons of radioactive waste in the desert 90 miles from Las Vegas.
Bush issued a written statement after signing the measure in private, with no ceremony. The house and senate approved the Yucca Mountain plan earlier this year, over the objections of Nevada’s senators.
Environmentalists maintain questions about storing and transporting the nuclear materials are largely unanswered.