Decades-long Yucca Mountain battle could flare up

"The Yucca Mountain project is hanging by a slender thread," Halstead said. "If this case goes against the NRC, it keeps the project alive, but without any new resources."

The Nuclear Regulatory Commission simply can't pay the project's enormous bills without an appropriation, he added. Yucca Mountain has been almost universally opposed by Nevada's elected officials, most notably Senate Majority Leader Harry Reid.

Should the court rule to continue the licensing process as Hallstead expects, vetting the more than 200 challenges filed against the project would likely take four to five years. Those challenges are not just coming from Nevadans, Halstead said.

"For the first time in almost 30 years, there are serious efforts under way nationally to find solutions to the nuclear waste problem that do not involve Yucca Mountain," he told committee members.

An estimated 72,000 tons of spent nuclear fuel is being stored at operating and closed reactors in 35 states as officials seek a long-term storage solution.