Water activity found at Yucca

Mary Manning and Mark D. Preston

Tuesday, Dec. 1, 1998 | 11:05 a.m.

WASHINGTON -- A new report released this morning indicates deep, hot water rose inside Yucca Mountain sometime in its history, throwing still more doubt on the site's suitability as a repository for high-level nuclear waste.

The Department of Energy's plans for disposing nuclear waste at the Nevada site, scheduled for congressional review later this month, assume the underground area 90 miles northwest of Las Vegas will remain dry for centuries.

The new scientific information discovered in mineral samples taken from the mountain in June indicates that tiny pockets of fluid trapped inside the crystals, called fluid inclusions, came from deep, hot water. The new information indicates geothermal activity under the site, which could endanger any buried waste.

"The term I would use is troubling evidence" said Yuri Dublyansky, the Siberian scientist about his study's preliminary findings.

The key, Dublyansky said, is when the crystals were formed. He estimates the samples he studied are about 160,000 years old, but he said this is "a very rough preliminary estimate." Dublyansky is waiting to hear from the DOE about the possibility of a joint study to date the minerals and shed some light on the danger that might be posed by possible geothermal activity.

Dublyansky said he thinks it will take between one and three years of intensive study to find the answers to his preliminary findings. He estimates the total cost for the study would be about $1 million.

"We need to study this in every detail... when did it happen, how often did it happen," he said. "Our present state of knowledge can't answer these question(s)."

The new information is based on trace quantities of hydrocarbons, leading Dublyansky to conclude that the fluid trapped in the crystals came from deep in the earth and invaded the proposed repository. Water rising inside a nuclear waste burial site could corrode containers, releasing high levels of radiation into the environment.

"This means that at some time in the past, the repository area was flooded," Dublyansky said.

A copy of his report was sent to the state of Nevada yesterday, Dublyansky said. And the Siberian scientist said he will make these findings available to Congress if asked.

The findings of hydrocarbon in the crystals are very preliminary and the evidence so far is scanty, he said. More studies are necessary.

Dublyansky, a geologist at the Siberian Branch of the Russian Academy of Sciences, took more than 30 samples from Yucca Mountain mineral deposits collected from cracks and crevices throughout the five-mile-long exploratory tunnel for several years. He said of the 10 samples he analyzed, seven of them had signs of fluid inclusion.

"My study is not conclusive, however," Dublyansky said. "The age of these mineral deposits is the most important question that needs to be resolved by further work."

DOE's scientists maintain that Yucca Mountain formed its unsaturated zone about 10 million years ago. Since that time, they say, the water table has never risen more than 300 feet above its present level. The water table is more than 900 feet beneath the proposed repository block.

Dating tests on the new evidence found by Dublyansky could confirm or refute those assumptions.

DOE scientists believe the crystals of calcite and opal examined by Dublyansky were formed by rainwater trickling through cracks and crevices in the mountain's tuff, a layer of the mountain formed during volcanic activity. That volcanic activity, millions of years ago, is when DOE scientists believe the area's water table last changed significantly.

The DOE has measured only seven samples of fluid inclusion and have said they have not found fluid inclusion in its samples. However, the DOE has only published an abstract of its report and has not released all of its data in findings.

The Institute for Energy and Environmental Research in Takoma Park, Md., retained Dublyansky to study the 1998 samples after the U.S. Geological Survey refused to conduct joint studies with him to confirm his preliminary findings based on mineral samples collected in 1995.

"A conclusion that Yucca Mountain would be a viable repository on the basis of present knowledge is scientifically inappropriate, because there is a significant body of evidence that points to the opposite conclusion," said Arjun Makhijani, president of the institute.

The institute is asking Energy Secretary William Richardson to delay release of the viability assessment, a report card on Yucca Mountain to Congress, until more work is done on Dublyansky's findings, such as determining the content of the crystals and the time the geothermal water rose inside Yucca Mountain, Makhijani said.

"It would be Alice-in-Wonderland science if the DOE issued a judgment about site viability first and then engaged in the scientific studies that are critical to one of the most crucial questions that affects viability," he said. "I say Alice in Wonderland because the judgment comes first and the trial comes later."

"Energy Secretary Richardson has promised the people of Nevada and the rest of the country that the decision about Yucca Mountain will be based on good science," Makhijani said.

The first draft of Dublyansky's report was subject to a wide range of fluid inclusion experts from the United States, England and France as well as reviewers selected by Lake Barrett, acting director of the DOE's Office of Civilian Radioactive Waste Management.

Almost all the reviews concurred in the high quality of the scientific work in the draft report.

Only one review, arranged by the DOE and done by Joe Whelan, James Paces, Brian Marshall, Zell Peterman, John Stuckless, Leonid Neymark -- all of the U.S. Geological Survey -- and Edwin Roedder of Harvard University, disagreed with some of the central scientific conclusions reached by Dublyansky. These reviewers agreed more studies are necessary.

But Makhijani said he was dismayed by the personal remarks toward Dublyansky, derogatory tone and factual inaccuracies the DOE scientists made in their report. He sent a letter to Barrett yesterday demanding they retract what he deemed as personal attacks.

"To throw epitaphs at the scientists who did this [report] is a disservice to the kind of problem that we are faced," Makhijani said. "I do believe this browbeating of other people outside of the establishment in deriding their work is a way of silencing debate on very crucial questions."

Dublyansky is a former consultant to the state of Nevada, which is opposing a nuclear waste repository at Yucca Mountain.

The Siberian scientist based his research on earlier work by former DOE geologist Jerry Szymanski, who first proposed that water rose periodically inside Yucca Mountain in 1989.

Szymanski subsequently quit the DOE's Yucca Mountain Project but continues to research his original findings, as well as Dublyansky's.

"The dates of that water mean everything," Szymanski said.