Scientists say water poses risk to nuke containers

Tuesday, Aug. 1, 2000 | 11:19 a.m.

CARSON CITY -- Nevada experts today challenged the material the Department of Energy plans to use for burying and containing 77,000 tons of highly radioactive waste inside Yucca Mountain.

State officials told the Nuclear Waste Technical Review Board that their research into C-22, a rare nickel alloy proposed for keeping nuclear garbage out of the environment for up to 1 million years, has some serious problems.

Scientists hired by the state subjected the alloy to water from Yucca Mountain and found that in less than 30 days the metal showed visible signs of corrosion. State officials brought photos of the corroded metal to show the review board today.

The special metal also has never been used in a volcanic ash environment such as Yucca Mountain, said Robert Loux, director of the state's Agency for Nuclear Projects.

The board is an independent panel overseeing scientific studies by the DOE on Yucca Mountain, 90 miles northwest of Las Vegas. The DOE is studying the mountain as a place to store highly radioactive wastes from commercial reactors and nuclear weapons development.

The DOE originally predicted the C-22 containers lined with stainless steel would last for up to 750,000 years. Its forecast has dropped to 34,000 years.

The metal was selected because it can stand up to sulfuric acid, a corrosive that could eat through the container and leak radiation into the environment.

The DOE explained its latest plans for barriers engineered to prevent water from contacting the containers. Federal scientists envision a series of titanium shields protecting the buried casks from the underground water, the DOE's project director, Abe Van Luik, said.

If the DOE is permitted to build a repository at Yucca, the casks filled with high-level nuclear waste would be buried in the year 2010 at the earliest. Underground they would reach 400 degrees Fahrenheit, well above the boiling point. Radiation from the wastes would attack the casks. And water laden with minerals would flow through the mountain, dripping onto the casks, state officials said.

Nevada officials said the site has too many serious problems to entomb nuclear wastes. Besides water flowing underground through the repository site, earthquakes and volcanic activity pose extensive risks, they said.

The Technical Review Board is expected to hear testimony on the latest research into earthquakes at Yucca, volcanic activity and the uncertain scientific evidence on the mountain during a two-day meeting in Carson City.

The DOE is in charge of Yucca Mountain studies. Congress singled out the mountain in 1987 as the lone site for reviewing a proposed national nuclear repository, the first such project in the world.