YUCCA MOUNTAIN, Nev. -- Squinting against the enveloping gloom, engineer Jim Niggemyer boards the dusty yellow mining train for its long slow descent into the depths of America's nuclear solution.
Far out in the bleak desert 100 miles northwest of Las Vegas, government researchers are busy drilling, heating and analyzing the depths of this ancient mountain for its likely future as the nation's first high-level nuclear graveyard.
Their goal is to transform Yucca Mountain by 2010 into the permanent home to 77,000 tons of highly lethal waste -- spent uranium and plutonium byproducts from nuclear-power plants, nuclear submarines and government test projects dating back to the testing of the first atomic bomb.
Housed in corrosion-resistant alloy canisters the size of compact cars, the fearsome cargo is so radioactive that momentary exposure would mean death within days, if not hours.
The nation's spent nuclear fuel is now stored at military bases and in cooling pools and dry storage at more than 100 reactors in 34 states. These sites require constant monitoring and repair.
The Yucca Mountain Project would hold the fuel for a virtual eternity. With its remote location and arid climate, officials estimate that the desert repository can isolate the waste for at least 10,000 years -- at the end of which, they predict, much of the radioactivity will have diminished.
Still, researchers are trying to gauge the mountain's suitability for a seemingly unfathomable 100,000 -- and even 1 million -- years into the future.
For Niggemyer, the project is a permanent answer to a nagging nuclear-waste problem that has perplexed the nation for generations. Since the 1950s, researchers have recommended pie-in-the-sky disposal solutions ranging from launching the waste into the sun to burying it beneath the ocean floor or the Earth's polar icecaps.
Niggemyer is among scores of researchers who have devoted years or decades of their lives to the project. They hope they are working on mankind's most enduring engineering achievement, one that for a time at least will defy nature's fierce destructive powers.
"When it's finished, this repository will be unlike anything that's ever been accomplished in human history," Niggemyer shouts over the train engine's drone. "This site will still be doing its job 100,000 years from now."
Critics are less sure. They say the $35 billion project -- to be funded mostly by fees paid by nuclear-energy customers -- is a laughable combination of high-level waste and low-level logic that will pose a serious health threat to future generations.
Angry Nevadans, some of whom have become quick studies in the rarefied realm of nuclear physics and soil geology, say the mountain is too porous to hold nuclear waste and that over the eons surface water will penetrate the protective casings and enter the water table, carrying radioactive particles to California's Death Valley and beyond.
They say the government's chosen site is susceptible to earthquakes. Pointing to a magnitude 5.6 quake 12 miles away at Little Skull Mountain in 1992, locals say the Yucca site sits amid a seismic minefield. One good temblor, they say, could crack open the waste containers like peanut shells.
Critics are also concerned about the danger of transporting spent nuclear fuel to Yucca Mountain from reactors nationwide, past 51 million people in 43 states. The chance of an accident or terrorist attack moved Sen. Richard H. Bryan, a Nevada Democrat, to dub the transport scenario "Mobile Chernobyl."
But project researchers say the present generation has an ethical obligation to deal with the nuclear waste in its lifetime. "We're the ones who made it, so we're responsible for its disposal," says Michael Voegele, a senior project engineer.
In the 1980s, the U.S. Department of Energy settled on three states as the most likely sites to bury the nation's nuclear waste: Texas, Washington and Nevada. But in 1987, Congress called the selection process too costly and zeroed in on Yucca Mountain.
The location has yet to be approved by Congress. The 5.4-mile, U-shaped tunnel was bored into the side of the mountain at a cost of $80 million solely to allow access for tests. Only after winning congressional blessing would the Energy Department construct a honeycomb of 35 miles of additional tunnels to house the waste.
If all goes well for the scientists, the first waste would arrive in 2010, loaded by remote-control locomotives. After 20 years, the mountain repository would be sealed, essentially forever.
Wearing earplugs and safety goggles, engineers communicate in manic sign language as Niggemyer leads a tour group past experimental sites deep within the Yucca Mountain rock.
Since the main tunnel was bored in 1992, Yucca Mountain has become what Niggemyer calls the "most studied piece of rock in human history," probed around the clock by the scientists and engineers who labor inside the jagged mountain ridge that rises about 1,000 feet above a dusty southwestern Nevada plain known as Jackass Flats.
"We're examining climates a million years past to see what might happen in the distant future, to determine the behavior of this mountain when the bulk of North America will be under ice," says Abe Van Luik, a senior project scientist. He says glaciers should next dominate North America 10,000 years from now.
Researchers have studied the dung piles of ancient pack rats, looking for clues to past climates and vegetation that can be used for a glimpse into the future. They've monitored heaters set at 350 degrees to simulate how the waste will literally cook the mountain, changing its rock layers in ways scientists seek to understand.
After assuming for years that most surface water would evaporate in the desert, project scientists acknowledge that water will, in the end, have its way. Tens of thousands of years from now, surface water will invade the canisters and -- after being exposed to the decaying waste -- be carried away by the underground water table.
But the researchers believe that communities around the site might be able to live with some degree of radioactivity. To gauge the waste water's effect on future generations, they have used a computer to invent a fictional farming community in nearby Amargosa Valley 10,000 years from now. They are studying the possible radioactive exposure of residents and livestock that might drink water tainted by nuclear waste.
The Nuclear Regulatory Commission has proposed limiting the annual radioactive exposure of local residents to 25 millirems from their water -- the equivalent of two X-rays -- and Yucca Mountain scientists are considering alternative waste-package designs to meet or exceed the proposed standard.
Project opponents say any water seepage resulting in increased radiation exposure is unacceptable. "There shouldn't be any exposure whatsoever," says Judy Treichel, director of the Nevada Nuclear Waste Task Force, a group that opposes the project.
Pub Date: 9/09/99