Las Vegas Sun

March 29, 2024

Nevada officials, scientists continue to spar over Yucca radiation standard

WASHINGTON -- Health physicists and radiation experts say the new proposed radiation standard for Yucca Mountain poses no significant health threats.

But Nevada officials say the government would unfairly put future residents living near Yucca at higher risk for cancer and other radiation-related illnesses than residents of other states.

The Environmental Protection Agency on Tuesday renewed a debate -- and sparked a controversy that likely will land in court -- about just how much radiation could acceptably leak from the proposed nuclear waste repository at Yucca, 90 miles northwest of Las Vegas.

The EPA announced that it had set a radiation-release standard designed to protect Nevadans for 1 million years -- an unprecedented scientific effort for the agency.

The EPA proposed a "two-tiered" rule. One tier sets a standard for up to 10,000 years at 15 millirem, roughly equivalent to a chest X-ray. That means the repository would be required to contain radiation for 10,000 years so that people living near Yucca would not receive a higher dose than 15 millirem in one year from the waste stored inside Yucca's underground tunnels.

The second tier would set a standard for 10,000 years to 1 million years at 350 millirem. That's unacceptably high, Nevada officials say.

"This is 350 millirem of involuntary exposure equal to about 35 chest X-rays a year," said attorney Joe Egan, who handles Yucca issues for the state. "Pregnant women aren't supposed to get any. This is a departure from all principles of radiation science."

Egan argues that the current regular allowable "public dose" from a nuclear power plant or other facility using radioactive materials is 100 millirem per year, based on recommendations by the National Council on Radiation Protection and Measurements and rules adopted by the Nuclear Regulatory Commission.

This alone makes the EPA's standard three times higher than what is deemed acceptable now, Egan said.

He said a low-level radioactive waste dump has a 25 millirem limit out to peak dose -- the time the radiation levels would be at their highest. Low-level waste is "far less dangerous" than what would be stored in Yucca, and it has a stricter standard, he said.

"This is increasing the level of risk to Nevadans," Egan said.

The exposure may not be enough to kill someone outright, but it could lead to serious illnesses over time, he said.

A person receiving 350 millirem in additional radiation exposure is put at higher risk than others, Egan said.

"It is a very significant increase in risk," he said.

Rod McCullum, senior project manager for waste at the Nuclear Energy Institute, the nuclear industry's interest group, agreed that the agency standard is higher than what would be allowed from a nuclear power plant, but he said it is not a fair comparison.

"It's comparing apples to oranges over time," McCullum said. "Everything is known with a nuclear power plant. There is a known quantity. There is nothing else in the world that is regulated for 1 million years. It is not a legitimate analogy."

And while the proposed standard of 350 millirem for Yucca is more than three times the 100 millirem standard for nuclear power plants, the difference does not automatically translate into severe health problems, experts said.

Controversy exists over what level of radiation exposure would cause cancer. Some scientists argue that no level of radiation is safe, while others say small doses are good for you, said Richard Morin, chairman of the American College of Radiology Medical Physics Commission.

"Three-hundred-fifty millirem falls into an area with no conclusive scientific data that it would cause health problems," said Morin, who is the Brooks-Hollern professor at the Mayo Clinic in Jacksonville, Fla. "That level is certainly consistent with natural background radiation."

Americans on average receive "background" radiation from a number of sources, including the cosmic rays from outer space, the earth, rock and radon gas often found in homes.

Several radiation experts, as well as EPA officials, point to the average 700 millirem of background radiation that people receive in the high-elevation city of Denver.

That's about the same level as what the EPA has said would be acceptable near Yucca after 10,000 years -- roughly 350 millirem in normal background radiation and 350 millirem from Yucca.

Phillip Patton, a UNLV assistant professor of health physics, noted there is no abnormal rate of cancer in Denver.

"By increasing our background radiation, we would be no different than if we all moved to Denver," Patton said. "It seems 350 millirem would cause no problems."

Ralph Andersen, NEI's Chief Health Physicist, said he has worked around radiation most of his life and would not be concerned about a 350 millirem exposure. He would not consider the level unsafe for his family either. He said he might try to avoid it, but he also would not pick up and move out of Colorado or other places with a high background level of radiation just because of exposure.

"I don't think people look at that as a dangerous level of radiation," he said.

Nuclear power plants or radioactive medical facilities no longer in use have a public exposure range of up to 500 millirem per year for up to 1,000 years, Andersen said. That rule has already been approved and is used by the Nuclear Regulatory Commission so the proposed Yucca limit could not be harmful, he said.

Andersen said exposure to 350 millirem could add incremental risk for people living around the repository but that no studies have shown cancer caused at that level. It is usually only seen at higher levels, he said.

The long-term effects of radiation are harder to argue and harder to measure, Patton said.

It is unethical to purposely expose someone to radiation to measure the risks, so there is a limited amount of data, experts said.

Experts say the more exposure people have to radiation, the more likely it is to cause cancer, but the exact level at which radiation triggers cancer is not known, Morin said.

Peter Caracappa, a radiation safety officer and a research associate at Rensselaer Polytechnic Institute in New York, said there is a debate over the true effect of radiation at certain levels.

"This is not a line between safe and not safe," Caracappa said. "It is a continuous risk exposure."

Although there is no threshold, Caracappa said, the level is much higher than the 350 millirem the EPA would allow at Yucca.

"You are not talking about high levels of radiation," said Carol Kornmehl, a radiation oncologist, speaking of the 350-millirem level. "This is not a high exposure, it is not likely to cause health problems."

Kornmehl said a CAT scan to the chest can expose a patient to 760 millirem. The same test to the abdomen and pelvis has 2,760 millirem.

Kornmehl, author of "The Best News About Radiation Therapy," said the standard proposed for Yucca is "probably acceptable," but that the government needs to explain to the public what the 350-millirem radiation level means.

Morin said a 100,000 millirem single exposure to the eyes could cause cataracts and 200,000 millirem single exposure would redden skin and make a person ill.

Morin said international flight crews can receive more than 350 millirem in a year and some patients are exposed to that amount for certain procedures.

"A radiation worker in a plant can get 5,000 millirem per year," Morin said.

Nevada's Egan counters that a plant worker is there voluntarily, knows the risks and is compensated well for his or her work associated with that risk, while the EPA standard puts people involuntarily at risk.

Egan points out that in finalizing the initial radiation standard, which a court threw out last year, EPA acknowledged that the National Academy of Sciences recommended a 2 to 20 millirem limit per year for an unspecified amount of time.

"How is 350 'based upon and consistent with' this recommendation?" Egan asked.

The court required EPA to make a new standard based on the National Academy of Sciences recommendation, as Congress stated in the Energy Policy Act of 1992.

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