Nevada challenges durability of proposed nuclear storage casks

Nevada's experts this week will challenge the durability of the casks federal officials want to use to store nuclear waste at Yucca Mountain.

In a rare Carson City meeting of the Nuclear Waste Technical Review Board, state officials will present the results of research they have been conducting into the durability of the exotic nickel alloy C-22, which federal officials originally hoped could contain the radioactive garbage for 750,000 years.

Susan Zimmerman, administrator of Technical Programs at the Nevada Agency for Nuclear Projects, said there are some serious potential problems with the material.

She said the U.S. Department of Energy originally predicted casks made of C-22 and lined with stainless steel would last 750,000 years.

"Then they dropped it to 100,000 years and now they're down to 34,000 years," she said. "So we think they have evidence of some problems as well."

She said the material was selected because it is able to stand up to the corrosive effects of sulfuric acid.

"But it's never been used in this type of environment before and never to contain anything radioactive," she said.

If Yucca Mountain is built, the casks would be filled with high-level radioactive garbage and stored underground. They would be at temperatures in excess of 400 degrees Fahrenheit, bombarded by radioactivity and, Nevada officials say, subjected to a stream of mineral-laden water dripping from the underground rocks.

"We know there are some major problems with the material and we're going to present them," said Zimmerman.

The Technical Review Board will hear testimony on C-22 and a variety of other issues in two days of meetings starting Tuesday at the Pinon Plaza on Highway 50 East.

The board will hear testimony on the latest plans for an engineered barrier system and the proposed shields that would prevent water boiled out of the rock at Yucca Mountain from dripping on and corroding the nuclear waste casks.

Also on the agenda is a discussion of DOE's proposal to use a computer model to determine whether the agency's projections of how Yucca Mountain would work are accurate.

Department of Energy officials have been charged with finding a way to safely use Yucca Mountain to store the nation's high-level nuclear waste. Nevada officials say the site has too many serious problems from earthquake and potential volcanic activity to underground water flows in the mountain as well as the unproven durability of the storage casks.