Scientists propose different limits for Yucca Mountain

Monday, Sept. 27, 1999 | 5:05 a.m.

Government scientists have proposed two different radiation limits for a high-level nuclear waste repository at Yucca Mountain. But independent scientists question whether either standard will protect the public's health.

Those questions will be debated in public hearings the Nuclear Regulatory Commission and Environmental Protection Agency recently set for next month in Las Vegas.

The nuclear commission and EPA have introduced two different standards of radiation that would be allowed to escape from a proposed repository for high-level radioactive waste at Yucca Mountain, 90 miles northwest of Las Vegas.

The Nuclear Regulatory Commission has offered a limit of 25 millirems per year that a person living outside the gates of Yucca Mountain could be exposed to. It offers no limit as to how much radiation could escape through ground water.

The NRC is an independent government agency charged with licensing projects such as a nuclear waste repository.

The Environmental Protection Agency, the federal organization with the legal authority to set the radiation standards for Yucca Mountain, settled on a limit of 15 millirems' exposure, and would restrict the amount of radiation that would be allowed to escape through ground water at 4 millirems.

The nuclear industry opposes the EPA limits, saying that such a strict standard could kill the repository project.

The Energy Department's goal is that the 70,000 tons of nuclear waste expected to be buried at Yucca Mountain would leak practically no radioactivity for at least 10,000 years.

But the DOE admits that goal is unfeasible.

Its draft environmental impact study estimates that radiation will escape from buried containers by both water and air. Repository workers, drivers, transportation inspectors and people living within 50 miles of the site will receive radioactive exposures, though the impact statement says they won't be dangerous levels.

One critic, nuclear physicist and physician John Gofman, puts it bluntly: "There is no safe dose of radiation."

Gofman has studied nuclear weapons, nuclear waste and X-rays and how they have affected people for the past 50 years.

"Small doses of radiation over time add up to a lot of cancers," Gofman said in a telephone interview with the Las Vegas Sun from his Berkeley, Calif., office.

And radiation from Yucca Mountain could get stronger over time, another expert said.

Nuclear engineer Thomas Pigford, who served on a national panel to review radiation exposure standards for Yucca Mountain, disagrees with the DOE's limit of measuring radioactive releases only up to 10,000 years. "We must offer the same protection to future generations as we do to people today from licensed nuclear facilities," he said.

Pigford urged the regulators to estimate a radiation dose to a "reasonably maximally exposed individual," such as a farmer living in Amargosa Valley and drinking and irrigating his food supply with contaminated water.

But nuclear industry proposals for calculating the maximum dose appear to spread the radiation across a large population, diluting its impact, he said.