DOE officials are expected to submit a repository application next week to the Nuclear Regulatory Commission, ending more than a decade of delay.

McCain "put the flag up there and I did not see anyone in Congress saluting it," said the official who asked not to be identified because his company was not commenting on the proposal.

"It is so far removed from where we are in policy circles that I can't imagine it being discussed, even in bar talk," the official said.

After McCain's speech Tuesday in Denver where he said that an international nuclear waste site "could make it unnecessary" to open a facility at Yucca Mountain, his aides suggested he was thinking more along the lines of supporting Russia establishing a site in Siberia where nuclear waste from Asian and European nations might be guarded.

"The international spent fuel repository, first and foremost, is about what to do with spent fuel that resides in other countries," said Randy Scheunemann, McCain's senior foreign policy adviser.

But McCain is willing "to entertain the possibility that if the spent fuel repository is up and running, if the security and safeguards are sufficient that we could possibility send some of our spent fuel there too," Scheunemann said.

The concept of a single repository overseas for smaller nations and those with nuclear power startups makes sense, but not for the United States, which produces most of the world's commercial nuclear waste, said Per Peterson, a nuclear engineering professor at the University of California, Berkeley.

"It just would not be logical for the United States to send its spent fuel someplace else," Peterson said. "It would be a large-scale process to transport."

If the United States were to reprocess its nuclear waste, it would not be a large technical challenge to ship overseas the residuals from recycling, Peterson said.

But even if nuclear waste from commercial power plants were shipped elsewhere, a U.S. repository would still be needed for highly radioactive waste generated by the military over the years, Peterson said.

"It is difficult for me to see sending those materials to an international repository," he said. "I think that stuff, we really want to handle ourselves."

"Senator McCain was on the correct track in advocating for an international repository, but the remark about it providing an alternative to Yucca Mountain probably was off the cuff and probably in retrospect was misspoken," Peterson said.

Contact Stephens Washington Bureau chief Steve Tetreault at STetreault@stephensmedia.com or 202-783-1760.