Skeptical scientists concerned about missing Yucca data

Tuesday, Sept. 11, 2001 | 10:05 a.m.

Although a top Department of Energy official insisted government experts are ready to recommend Yucca Mountain as a nuclear waste repository this year, skeptical scientists said they still have concerns over missing data.

Scientists reviewing the DOE's studies on containers to bury 77,000 tons of nuclear waste inside the mountain called for the use of a metal other than a stainless steel alloy recommended by the agency.

The scientists spoke Monday during a meeting of the independent Nuclear Waste Technical Review Board in Las Vegas.

DOE Yucca Mountain chief Lake Barrett said Energy Secretary Spencer Abraham should recommend Yucca Mountain, 90 miles northwest of Las Vegas, by the end of the year.

At issue for scientists reviewing the project is how metals, designed to keep radiation from leaking out of about 12,000 buried containers and to protect buried wastes from ground water, will perform.

Roger Staehle of the University of Minnesota, North Oaks, said there is too much scientific data missing from computer models designed and constructed by the DOE to reach any conclusion.

Staehle, a consultant to Nevada officials who are opposing the repository, warned the technical review board to challenge the DOE.

He advised the DOE to store spent fuel at nuclear reactor sites in dry casks for up to 100 years before putting it anywhere, Staehle told the Sun.

"I'm concerned we have not faced up to realities," Staehle said. The DOE is not ready to proceed on the project, he said.

Scientists from around the world said moist dust resting on the metal surface of the containers, scale deposits on the metal or crevices in the containers could lead to radiation leaks.

Joseph Payer, the chief scientist reviewing DOE's containers, said the viability of C-22 -- the metal alloy preferred for burying the wastes -- has not been tested for more than 10,000 years.

"I, personally, don't think we're locked in to alloy 22," Payer said.

However, it would take at least 10 years to conduct detailed studies on an alternative metal, he said.

"It doesn't sound like a ringing endorsement (of the project)," Paul Craig, a member of the technical review board, said.

Bacteria, fungi, and chemicals in ground water could contribute to corrosion of the containers, but the DOE has not seen any problems with the metals in its own tests, Gerald Gordon of the DOE's Bechtel-SAIC company, said. Results from the DOE's studies should be ready next year, he said.

Consultants for Nevada's Agency for Nuclear Projects showed pictures of cracks in titanium, the metal the DOE plans to use as a shield for buried waste containers from ground water inside the mountain.

Placed in water from Yucca Mountain at temperatures of more than 100 degrees above boiling, pits, cracks and flaking of the titanium appeared in less than a month, said chemist April Pulvirenti of Catholic University of America said.

Studies done last year by Catholic University scientists revealed similar cracks in the C-22 container metal.