"John McCain has voted with the proponents of Yucca Mountain every time, without any question," Reid continued. "If he's president, Yucca Mountain would be a reality."

During a campaign stop in Nevada last week, McCain said he would base decisions on the project on science and make sure it met environmental and safety standards. While saying he still supported the proposed nuclear waste repository 100 miles outside Las Vegas, the Arizona senator expressed doubt that it would ever clear regulatory and legal hurdles and actually be built.

"You have to go through the process," McCain said in an interview last week. "In the past history of this country, we have made too many errors that have damaged our environment and people's lives."

Reid said he heard in McCain's words an attempt to have the issue both ways and echoes of the campaign promises of George W. Bush.

During the campaigns of 2000 and 2004, Yucca Mountain was a major point of contention as the candidates campaigned in Nevada. Both times, "sound science" was Bush's trademark as he vowed to move the project forward based on the evidence.

"I believe sound science, and not politics, must prevail in the designation of any high-level nuclear waste repository," Bush wrote in a letter to Nevada's then-Gov. Kenny Guinn dated May 3, 2000. "As President, I would not sign legislation that would send nuclear waste to any proposed site unless it's been deemed scientifically safe. I also believe the federal government must work with the local and state governments that will be affected to address safety and transportation issues."

On Feb. 14, 2002, Bush recommended Yucca as the site for 77,000 tons of radioactive waste based on studies by the Department of Energy.

During the 2004 presidential campaign, Democrat John Kerry highlighted the move, which he called a broken promise. Bush again used "sound science" as his byword to claim that he would only go forward with the project if it was shown to be safe.

Bush narrowly won the state, and his administration has continued to push forward with the repository. To the state of Nevada, which maintains an official position against the project, the promise to adhere to the evidence has not been kept.

"We refer to the (Department of Energy's) kind of science as advocacy science," said Bob Loux, executive director of the state's Nuclear Projects Agency. "That's when you only go about collecting the data and information that makes your case, and ignore other data that suggests the opposite."

Loux noted that the Energy Department recently submitted its license application for the site despite the fact that a court in 2004 threw out proposed health and safety standards. "So we really don't even know what standards Yucca Mountain is supposed to meet," Loux said.

In a Review-Journal poll conducted last month, 52 percent of Nevadans said a candidates' stance on Yucca Mountain would have at least some influence on how they vote.

While Reid accused McCain of softening his rhetoric for political purposes, a McCain campaign spokesman denied the charge.

"That implies that the senator (McCain) has changed his position when he hasn't," Rick Gorka said. "Senator McCain believes that Yucca Mountain is necessary, but he wants to ensure that it's environmentally safe and sound. The senator has always said there is a need for Yucca Mountain, but it needs to be based on sound science."

Gorka charged that it is McCain's opponent, Democrat Barack Obama, who has tried to have it both ways on the issue. Obama has said he would end the project.

Gorka pointed to a massive 2005 energy bill that contained $557 million in funding for Yucca. "When Senator Obama votes for that, it contradicts Obama's message," he said. "You can say you would kill it in an election year, but in 2005 you vote for $557 million to fund it? That is, to me, a glaring change in his position."

Both Nevada senators, Reid and Republican John Ensign, voted for the bill, which Reid had worked to trim by $150 million from the amount Bush originally requested for Yucca.

Obama spokeswoman Shannon Gilson said Obama's vote on the bill did not represent a vote in favor of Yucca Mountain, which he has consistently opposed.

Contact reporter Molly Ball at mball@reviewjournal.com or 702-387-2919.