Sproat, director of the DOE's Office of Civilian Radioactive Waste Management, said he hasn't written off the June goal. But in an interview, he suggested the date was unlikely and could slip.

"I don't know if we will be able to make June 30 or not," he said. "I am cautiously optimistic that we could get an LA (license application) in sometime during calendar year 2008."

Energy Department officials have conceded the budget cut engineered late last year by Sen. Harry Reid, D-Nev., struck a big blow to the project that already is 10 years behind schedule. Reid and other Nevada leaders say the repository for 70,000 metric tons of highly radioactive spent fuel will be flawed and unsafe and should be stopped.

The Bush administration requested $494.5 million for the fiscal year that began on Oct. 1. Congress in December approved $386.5 million. "That is a major cut in the program, and it hurts, and it is impacting us severely," Sproat said.

Major contractors, including Bechtel SAIC Co. and Sandia National Laboratories, will report in six to eight weeks how they would absorb the loss and whether a June application is doable, Sproat said.

In a license application likely to number thousands of pages, the Energy Department would venture to show that nuclear waste could be handled safely at Yucca and buried within the mountain for hundreds of thousands of years.

The Energy Department had advertised its June goal to Congress and to the nuclear industry in a bid to show that new managers, including Sproat, were turning around the program. Sproat, a former industry executive, was appointed in May 2006.

But, Sproat said, "rules got changed in the middle of the game" as Congress failed to supply adequate funding "six months from the finish line."

Bob Loux, a critic of the project and head of Nevada's Agency for Nuclear Projects, said DOE blaming Congress "is an easy way out." He contended that a well-run program would not have been rushing to make deadlines.

"It is a convenient scapegoat, but (DOE) has missed almost every deadline they have ever established," Loux said.

There already have been several rounds of job cuts. Most recently, Bechtel SAIC Co. virtually shut down operations at the repository study area, giving layoff notices last week to 63 workers who were maintaining the site 100 miles northwest of Las Vegas.

The mouth of the 25-foot-diameter exploratory tunnel has been fenced off as a skeleton crew of fewer than a dozen workers maintains the site, monitoring plumbing, ventilation and electrical equipment.

Sproat's remarks came ahead of two presentations he is to deliver this week in Las Vegas. Today, he will address the legislative Committee on High Level Radioactive Waste at 9:30 a.m. at the Sawyer Building. Wednesday, the Nuclear Waste Technical Review Board, an expert panel that reports to Congress, will meet at 8 a.m. at the Marriott Suites Convention Center hotel on Convention Center Drive.