Yucca design raises doubts

Monday, Jan. 8, 2001 | 11:28 a.m.

An independent scientific board is criticizing a proposed high-level nuclear waste repository at Yucca Mountain, saying the Energy Department cannot support its basic design.

In a year-end report to Congress and to Energy Secretary Bill Richardson, the Nuclear Waste Technical Review Board noted that too many unanswered questions remain about the DOE's current repository design if Yucca Mountain, 90 miles northwest of Las Vegas, is to be recommended later this year.

The DOE's preferred design allows the proposed repository's temperature to rise above the boiling point of water.

"In the board's view, the DOE has not yet demonstrated a firm technical basis for its present high-temperature 'base case' repository design," review board Chairman Jared Cohon wrote in a Dec. 20 letter introducing the report.

The board, formed in 1987 by Congress, oversees the DOE's scientific studies at Yucca Mountain. It must report to Congress at least twice a year.

Over the past year the board has expressed concern about the DOE's lack of information about and subsequent proof for its preferred design of a repository at Yucca Mountain for 77,000 tons of highly radioactive wastes from commercial nuclear reactors and weapons activities.

The design assumed in DOE's analysis of the safety of a repository allows heat from the buried nuclear wastes to rise above boiling -- 212 degrees Fahrenheit.

The review board said it is not in a position to recommend a specific design, because it does not have the authority to do so. However, it suggested a cooler cavern, one that would spread the wastes over more area.

A larger and cooler repository would add from $600 million to $2 billion to the repository's price tag. The latest cost estimate by the DOE is $58 billion.

The board said that while the DOE has made progress during its 15 years of scientific studies at Yucca, crucial information is missing, such as data that supports the repository design; analysis of chemical reactions between the mountain's rock, nuclear waste containers and ground water; and forecasts of what would happen to buried waste containers during a volcanic eruption.

The technical review board has scheduled a two-day meeting Jan. 30-31 in Amargosa Valley, 97 miles northwest of Las Vegas. The board's meetings are open to the public.

The DOE's Yucca Mountain experts intend to respond to some of those scientific and technical questions at that time, DOE spokeswoman Gayle Fisher said.

The board also has invited to speak nuclear waste expert Jean-Claude Duplessy, a member of a national scientific evaluation panel that oversees scientific and technical activities for nuclear waste management in France.