The three-judge panel dismissed claims by Nevada that the Bush administration's plan to build the Yucca Mountain waste site was unconstitutional and said that actions by the Energy Department and President Bush leading up to approval of the waste site were not subject to review by the court.
In a victory for Nevada, however, the court rejected the government standard that the public would have to be protected from radiation leaks only for 10,000 years. It said the compliance period for the radiation standards would have to be developed well beyond that period.
The 100-page decision by the three-judge panel of the U.S. Court of Appeals for the District of Columbia was a major blow to Nevada's attempt to block construction of the repository planned for 90 miles northwest of Las Vegas.
The state was likely to appeal the decision and also has vowed to continue fighting the case before the Nuclear Regulatory Commission, which must issue a permit for the facility. The site is planned to store underground 77,000 tons of highly radioactive waste, mostly spent reactor fuel from commercial power plants.
Congress approved the Yucca Mountain site in 2002, overriding an attempt by Nevada to block the project.
While rejecting the heart of Nevada's arguments, the appeals court upheld arguments by environmentalists that the Environmental Protection Agency requirements for safeguarding the environment from radiation were inadequate and would have to be strengthened.