Project to determine source of trapped water

Federal, state and independent scientists met today to map out a strategy for studying water and gas trapped in rocks at Yucca Mountain to answer a crucial debate about whether the site is safe to store highly radioactive waste.

Some independent scientists argue that water and gas bubbles inside Yucca Mountain, 90 miles northwest of Las Vegas, come from relatively recent rises of hot water from deep within the earth, making the site unsafe for storing the waste.

But others say the trapped gas and moisture formed from rainwater trickling into the mountain.

Today's meeting is the formal beginning of a two-year research project to try to determine the source of the water.

Department of Energy scientists thought the issue was important enough to contribute more than $1 million so UNLV associate geology professor Jean Cline could equip a laboratory at the university to study the liquid and gas trapped in crystals.

Cline received a contract from the DOE to lead independent research during the next two years to determine whether the water came from beneath the earth or from rain. UNLV is working with five agencies -- the DOE, the Nuclear Regulatory Commission, the state of Nevada, the U.S. Geological Survey and the Nuclear Waste Technical Review Board -- in the study, which could be pivotal to the future of the project.

After working in the Southwest exploring resources for mining companies, Cline came to UNLV 10 years ago to teach. Her specialty is studying the history locked in rocks.

"It's part of a huge experiment," Cline said. She said she expects each scientist to approach the research from a different view.

"Everyone will look down the microscope; everyone will be looking at sections of the rock samples," she said. But they will argue from diverse viewpoints.

Cline has gathered experts together this week to begin studies on the phenomenon, called fluid inclusion. The scientists -- including Siberian expert Yuri Dublyansky, who represents the state of Nevada and originally brought attention to the possible problem, and Drew Coleman of the DOE's Yucca Mountain Project Office -- will share their information and their views.

"It's a cooperative effort as well as an independent project for those who want to do science," Coleman, a DOE geologist, said.

The scientists will visit Yucca Mountain this week to gather new samples of rock from the 5-mile exploratory tunnel. It will take months to prepare the razor-thin slices of rock for observation.

Dublyansky has sampled more than 300 crystals containing calcite and opal from the mountain. He concluded those deposits, formed as deep geothermal water, rose inside Yucca Mountain. How long ago the water invaded the mountain is unknown.

Many questions remain unanswered, Dublyansky said. "How much water came into the mountain? When? How often?"

Those are just some of the questions the scientists hope to answer in the course of their work.

Dublyansky issued a report in December and urged joint studies of the evidence in the Yucca Mountain rocks. While the DOE criticized Dublyansky's work, the agency agreed that further studies were necessary.

If within the past 1 million years the water reached the area where the DOE plans to bury the nation's nuclear waste, Dublyansky concluded, Yucca Mountain would be the wrong place for a radioactive repository. Radiation will reach its highest peak within the mountain between 100,000 years and 1 million years, he said in a report prepared for the state.

Robert Bodnar, an expert who taught Cline at Virginia Polytechnic Institute and reviewed Dublyansky's work for the Nuclear Waste Technical Review Board, has kept an open mind and will act as an independent consultant for the study.

Although Bodnar originally did not agree with earlier studies of the deposits, he has since reconsidered and said the fluids in the crystals were formed from hot water. He also said that evidence of hydrocarbons indicate a source deep within the earth.

By the time the fluid inclusion study is done, the DOE expects to be ready to recommend whether Yucca Mountain can be a permanent nuclear waste repository.

archive