Panel Tackles Desert Nuclear Waste Issue : Environment: National Academy of Sciences studies proposed Ward Valley facility. The crucial issue is whether radioactive contamination in the Mojave could trickle down to drinking supplies.

At the local Elk’s Lodge in this dusty, overgrown truck stop, 16 of the nation’s leading geologists, geophysicists and geochemists Thursday began assessing the wisdom of burying radioactive waste in a desolate strip of the eastern Mojave Desert 20 miles to the west.

The appointment of the panel by the National Academy of Sciences, the country’s oldest and most prestigious scientific body, marks the first time an independent group of experts has become involved in the decade-long controversy over the proposed Ward Valley nuclear waste disposal facility.

The crucial issue for the National Academy panel is whether moisture, contaminated by buried radioactive waste, could trickle down 600 feet to the water table, migrate to the nearby Colorado River and poison the drinking water supply of millions of people in California, Arizona and Mexico.

In a spirit of scientific candor, the three-day meeting began with an acknowledgment by an official supporting the dump that resolving all doubts about its safety will be difficult.

“I would be the last person to claim that definitive answers to all the detailed questions that (Ward Valley opponents) have raised are known today,” Elisabeth Brandt, chief counsel for the California Department of Health Services, told the panel.

Pointing out that people are exposed to small amounts of radioactivity every day, Brandt insisted that it is not necessary to show that no radioactive material would ever leak from Ward Valley. “To demand proof that, no matter what the circumstances, there will be no release whatsoever is simply unrealistic,” she said.

“For this reason (the U.S. Nuclear Regulatory Commission) has established reasonable health and safety standards which we must prove that we can meet.”

The panel’s examination of the dump site--requested by Interior Secretary Bruce Babbitt--will focus on a deceptively simple question. Do raindrops falling in the desert evaporate before they can replenish the ground water supply some 600 feet down?

The answer could go a long way toward resolving the controversy over the suitability of the federally owned site and persuading Babbitt whether to transfer the 1,000 acres in question to the state for use as a nuclear dump.

Babbitt has said he will not transfer it to California until he is convinced of its safety. He has asked the National Academy panel to give him a report by year’s end.

If the scientists determine that moisture does not penetrate deeply into the desert, a strong case can be made that nature has created an impermeable crypt safe for burying some of the most long-lived and toxic materials known to man.

Yet, there is evidence of moisture in the ground, and, although no radioactive waste is stored in Ward Valley now, tiny amounts of radioactive tritium have been detected 100 feet below the surface.

Tritium occurs naturally in the Earth’s atmosphere and also is a byproduct of past atmospheric nuclear testing. It could have made its way into the ground beneath Ward Valley in a vaporous form. But if water is to blame for its presence, there could be a big problem.

If Ward Valley is opened, tritium waste from biomedical laboratories could account for up to 90% of the radioactivity in the dump. If the material gets wet, the soluble tritium will go wherever the moisture goes, remaining hazardous for more than 200 years.

Unlike the tritium there now, all waste would be hermetically sealed in metal containers. But the containers will decay over time.

The state’s experts point to studies showing that moisture moves much too slowly--about 4 centimeters in 1,000 years--to pose a threat. They argue that any waste particles leaking out of the dump would lose their radioactivity before reaching the ground water.

But Mark Liggett, a geologic consultant who has worked in Ward Valley for 20 years, told panel members Thursday that the depth of the water table and the moisture content of the ground above varies widely. Liggett said the state’s research is not thorough enough to reflect the variations.

While its arid climate has been a selling point for Ward Valley--which receives only about 5 inches of rainfall annually--that may not have always been the case. Steve Hostettler, a climatologist with the U.S. Geological Survey, told the panel that the site has been a lot wetter during periods over the past 10,000 years.

“We just can’t say whether those conditions will recur,” he said.

The controversy over the dump has become the focal point of a national dilemma over what to do about accumulating waste from critical industries such as nuclear medicine. Currently, 31 states, including California, have no place to legally dispose of radioactive waste.

The Ward Valley dump would be the first of a new generation of state-operated nuclear facilities and the first to open in more than a quarter century.

The dump, if built, will consist of five sealed, underground trenches designed to take an estimated 5.5 million cubic feet of waste from nuclear power plants, hospitals, laboratories and manufacturing companies. The facility is expected to operate for 30 years, although much of the waste will remain hazardous for several hundred years, and a portion will be toxic for thousands of years.

The panelists have indicated that they want to know if the waste trenches will be invulnerable to runoff in the event of flooding, and, if they aren’t, how moisture will be prevented from leaving the trenches. They also want to know if the buried waste could pose a hazard to local plants and animals, including the desert tortoise now the Endangered Species List and categorized as threatened.

The National Academy panel was under fire even before its first meeting. The Sierra Club, Physicians for Social Responsibility and other groups opposed to the dump charged that several panelists had close ties to the nuclear industry.

“My view is that it is a rigged jury,” said Dan Hirsch of the Committee to Bridge the Gap, one of the groups opposed to the dump.

Meanwhile, both sides in the debate have been focusing on the tritium issue, offering very different explanations for its presence under Ward Valley.

Opponents say the tritium originated as fallout from atmospheric testing of hydrogen bombs in the 1950s. If that’s the case, it was able to travel 100 feet into the ground in less than 50 years. The only explanation, opponents contend, is the downward movement of moisture.

If that is so, the prognosis for the Ward Valley dump may not be good. It would mean contaminated moisture may travel fast enough to reach the water table while much of the radioactive waste still is toxic.

Consultants for the California Department of Health Services maintain that if the tritium in the ground was water borne, concentrations would be much higher.

Supporters point out that concentrations are 6,000 times less than what is allowed under the state’s safe drinking water standards. That means, supporters say, the tritium arrived there as a result of gaseous diffusion--a process that would have rendered the material harmless well above the water table.

Both sides point to studies of another nuclear dump near Beatty, Nev., where the desert environment is believed to be virtually identical to Ward Valley. The Beatty dump now is closed.

From those studies, the Department of Health Services has concluded that moisture would not penetrate very far into the ground at Ward Valley before it evaporated.

Yet, tritium also was unearthed near the Beatty site. Found in a test well, it was about 400 feet down at concentrations that exceeded safe drinking water standards. It was found after the dump had been operating and receiving tritium waste for about 20 years.

“The finding of tritium contamination in monitoring wells contradicts assertions by Ward Valley proponents that radioactivity does not migrate in arid sites,” said opponent Hirsch.

Officials of the Department of Health blame the presence of tritium on human mischief.

“Everybody believes that well was spiked,” said Brandt, the department counsel.

But David Prudic, a U.S. government geologist who has studied the Beatty site, sounded less confident about that explanation when he addressed the panel Thursday.

“I’m not sure what to make of it at all,” Prudic said. “I can’t explain it. It’s a puzzle. I don’t know if it ever will be solved.”

The Evaporation Question

The controversy over the proposed radioactive waste dump near Ward Valley has focused on one issue: Does desert moisture evaporate before it reaches the water table?

If it does, there is little chance of any leaking waste contaminating the ground water supply; if it doesn’t, there’s the potential danger of the polluted water reaching millions of people through the Colorado River.

Here is a look at the proposed construction:

Proponents maintain:

Radioactive waste would be sealed in metal containers in large trenches.

While containers would decay over time, any water-borne waste would dry up faster.

Moisture does not penetrate far enough or fast enough to allow radioactive waste to reach the water table while it is still toxic.

Critics maintain:

Tiny amounts of one naturally occurring radioactive substance, tritium, have already been found 100 feet underground.

The tritium would not be there unless carried by moisture draining through the ground.

Waste buried in Ward Valley would eventually seep into the water supply.

20 feet: Trench ceilings when full.

42 feet: Bottom of one trench for radioactive waste.

60 feet: Bottom of four trenches for radioactive waste.

Ground water supply: 600 feet underground