The plan to open Yucca by 2020 - 22 years after it was initially projected to open - hinges on the Nuclear Regulatory Commission approving a license for the facility, for Congress to approve the arrangement and for enough money to be earmarked for the project.

Rep. Jim Matheson wants to take another route: leaving 77,000 tons of deadly waste where it was created.

The Utah Democrat reminded a Department of Energy official and others Tuesday at a House subcommittee hearing about a bill he introduced in 2005 to keep the waste at reactor sites under DOE oversight. He reintroduced the measure this session.

"The transportation of nuclear waste across the continent creates more problems than leaving it where it is," Matheson said, noting he does not oppose nuclear energy. "Even if we were to magically open Yucca Mountain today, we wouldn't have enough room for the waste we have."

A second waste site as big as Yucca Mountain, which could hold an amount about as large as is now stockpiled, may be needed to hold the rest of the nation's spent nuclear waste, said Edward Sproat, director of the DOE Office of Civilian Radioactive Waste.

If Yucca goes forward, between 87 percent and 95 percent of the 77,000 tons of radioactive waste could travel through Utah en route to the southern Nevada dump. Also, because Nevada couldn't hold all of the nuclear industry's waste, Utah could again be looked at as a potential storage site for spent nuclear fuel.

State leaders have for at least a decade fought a proposal from energy companies to build a temporary storage site on the Skull Valley Goshute reservation about an hour's drive from Salt Lake City.

Sproat said on-site storage of the nuclear waste won't solve the waste-disposal problem.

"It really becomes a question of for how long are you going to leave it there," Sproat said. "Eventually it's going to move, and the longer you leave it there, the more it's going to cost."

The cost to open and operate Yucca has swelled since the last time the DOE released an estimate of $58 billion in 2001. Sproat says the project, including the $9 billion already spent, and 100 years of operation could total $90 billion.

Sproat said a report on interim storage of nuclear waste as well as another on the need for a secondary repository are "imminent" but gave no firm date of when they would be released.

tburr@sltrib.com