The Environmental Protection Agency's proposal would limit exposure near the proposed Yucca Mountain facility in a Nevada desert to 15 millirem a year for 10,000 years into the future, but then increase the allowable level to 350 millirem for up to 1 million years.
That higher level is more than three times today's allowance from nuclear facilities as set by the Nuclear Regulatory Commission.
Exposure from a standard chest X-ray is about 10 millirem.
The proposed dump, planned to house spent nuclear fuel inside a mountain, has been approved by both houses of Congress and ordered by President Bush over the objections of virtually every politician in Nevada.
Sen. Harry Reid, leader of the opposition Democrats in the Senate, called the standard announced Tuesday the product of "voodoo science and arbitrary numbers." The state's other senator, Republican John Ensign, said the standard had no scientific basis and demonstrated "a blatant disregard for ... the health of Nevadans."
Asked if there was any way to assure that such a standard would be relevant or be met that far in the future, the EPA's Jeffrey Holmstead replied, "That's a pretty darn good question. ... We do the best job given all the science we have."
The radiation exposure issue has threatened to cripple the government's plans to bury 77,000 tons of highly radioactive waste, mostly used reactor fuel rods now at commercial power plants, beneath a volcanic ridge at Yucca Mountain in the Nevada desert 90 miles from Las Vegas.
A year ago a federal court said the EPA standard, meant to ensure nearby residents won't be harmed by radioactivity emanating from the dump, was inadequate because it didn't establish exposure limits beyond 10,000 years.
On Tuesday, the EPA announced a revised standard that reaches to a million years.
"That's longer, many times longer than human history," said Holmstead, adding that he's certain the rule will be protective of the public. Once the standard is made final after a comment period, the Nuclear Regulatory Commission will decide whether the Yucca facility's design is adequate to meet it.
"We're setting a standard that not only protects our children, our grandchildren ... it will protect the next 25,000 generations," said Holmstead.
But opponents of the Yucca waste project, including state officials in Nevada, saw it differently.
"In short, they've decided to kill a few people," said Joe Egan, an attorney who represented Nevada in the court fight over the project. "This is an obvious effort to give the project a pass" after the 10,000 year period."
Egan said the standard would allow as much as 700 millirem of radiation exposure a year, when added to the 350 millirem of natural background radiation in the Yucca area. The Nuclear Regulatory Commission, which must still approve a permit for the Yucca waste site, limits public radiation exposure from nuclear facilities it licenses to no more than 100 millirem per year.
Holmstead, who is the EPA's head of air and radiation office, said a person living near the Yucca site will not be subjected to radiation "higher than people are routinely exposed to throughout the country" from natural background sources.
"It's not a protective standard," said Judy Treichel, director of the Las Vegas-based Nuclear Waste Task Force, which opposes the Yucca project. "It's a way, I guess, for the EPA to help the Department of Energy build its dump."
By H. Josef Hebert