Yucca dump may have to be larger than planned

Monday, Jan. 26, 1998 | 10:40 a.m.

Much more highly radioactive waste is expected at Yucca Mountain, the only site under study as a national high-level nuclear waste dump, if today's reactors continue to operate.

At least 105,000 tons of irradiated reactor fuel could end up in Yucca Mountain, 90 miles northwest of Las Vegas, if the current 109 nuclear reactors keep producing electricity, said Wendy Dixon, the Department of Energy's assistant manager for environment, health and safety.

The Nuclear Waste Policy Act limits the waste to 77,000 tons today. It will take an act of Congress to change it.

While federal scientists heat up Yucca Mountain's volcanic rock, watch where water runs, and test for more than the 33 existing earthquake faults, they also have to plan on more room for the repository, Dixon said.

To entomb that much waste will take more than 20 years and more than 100 miles of tunnels inside Yucca Mountain.

It took the DOE three years to grind out five miles of tunnels through the mountain's tuff.

The energy secretary in the year 2001 will recommend the site to the president if he believes the mountain can be licensed by the Nuclear Regulatory Commission, said Stephan Brocoum, assistant manager for licensing.

The NRC could take up to four years for licensing and the first loads of reactor fuel are expected in 2010, if everything goes according to plan, Brocoum said.

How the mountain will keep radioactivity in place for tens of thousands of years is the major question, he said.

"You can't engineer the natural system," Brocoum told state and county officials last week.

The DOE is relying to a great extent on engineered barriers because the environment can change drastically over a long time period, he said. The environment and the engineered features have to work together, but neither lasts for eternity.

"Sooner or later the mountain is going to be eroded away," Brocoum said. "You can't contain it forever."

Even if the climate shifts to a lot wetter and cooler place, U.S. Geological Survey scientists have estimated that deep water will not rise more than 180 feet.

However, geologist Jerry Szymanski, who worked for the DOE at Yucca Mountain in the early 80s, theorized that a massive amount of water floods the mountain periodically and could cause a catastrophic radiation release.

Szymanski has been hired by the state of Nevada to study Yucca Mountain.

If Yucca Mountain is licensed, it will take approximately 23 years to build a repository, if everything goes according to plan.