The state of Nevada is again challenging the EPA's new radiation standard for nuclear waste in Yucca Mountain. The EPA issued the standards in response to a court's 2004 order that proposed repository be able to protect the public for 10,000 years. The U.S. Court of Appeals for the D.C. Circuit said the 10,000-year compliance period was not based on the National Academy of Sciences' findings and recommendations.

Nevada charges that the federal government's own data show that water infiltration will corrode nuclear waste packages and that radioactive substances could leak into nearby groundwater, which includes water sources used by Las Vegas 90 miles to the south.

The new standards will retain the dose limit of 15 millirems per year for the first 10,000 years after disposal and establish a 100-millirem annual dose limit from 10,000 years to 1 million years.

The state has argued in numerous lawsuits that, since highly radioactive nuclear waste and spent nuclear fuel from nuclear reactors remain radioactively lethal for hundreds of thousands of years, no form of manmade barrier or container based on known technology can be a safe, permanent repository for such wastes for such extended periods of time.