Another roadblock went up Wednesday in front of the planned Yucca Mountain Nuclear Waste Repository in Nevada, with claims that federal scientific studies were falsified.

The allegations — about the possibility of water seeping into the repository — seem likely to cause further delays and other problems at Yucca Mountain, where the nation's spent nuclear fuel rods were to be permanently stored, theoretically by 2010.

Even as Yucca Mountain continues to be scrutinized, the permitting process has been accelerating for a "temporary" storage facility for the same high-level radioactive waste in Utah's Skull Valley. The latest developments could impact Utah a couple of ways:

• They could make the proposed Private Fuel Storage plant in Tooele County more desirable to the federal government as a site for storing the highly radioactive waste from nuclear power plants. If Yucca Mountain's problems prove insurmountable, that could increase the odds that PFS is not only built, but it might become a permanent storage area, opponents fear.

• Or, a Utah official said Wednesday, the setback could convince the federal government to keep the nuclear waste at the power plants where it is being generated, as has been proposed by Sen. Harry Reid, D-Nev.

"I think that Skull Valley has always been an emergency Plan B" — a fall-back facility, said activist Chip Ward, a Utah author who has been worried about the PFS plant for years. "It was emergency Plan B for nuclear utilities, and now it may be emergency Plan B for the NRC," the Nuclear Regulatory Commission, which may soon approve the PFS proposal. "That's very disturbing," he said.

He called for Utah's U.S. senators to stop supporting the move to store waste at Yucca Mountain. That bandwagon, Ward said, has four flat tires.

Meanwhile, Denise Chancellor, assistant Utah attorney general, said the developments may make "Harry Reid's proposal more attractive, which is to keep the fuel at reactor sites until they can figure it all out." Reid, the Senate minority leader, opposes the Yucca Mountain project in his home state.

Chancellor is leading Utah's nearly 8-year-old fight against a "temporary" spent-fuel dump proposed for the Skull Valley Indian Reservation 45 miles southwest of Salt Lake City. She said she was filing a motion Wednesday asking the NRC's Atomic Safety Licensing Board to reconsider the danger that the Skull Valley canisters could break open and spread radiation if hit by a crashing aircraft under a military flight path.