Nuke study: Yucca ground stretching

Friday, March 27, 1998 | 9:54 a.m.

The ground around Yucca Mountain could stretch more than 3 feet over the next thousand years, a movement that could crush any canisters of nuclear waste waste buried there, exposing a wide area of the Southwest to deadly radiation, a study commissioned by the Nuclear Regulatory Commission shows.

Yucca Mountain, 90 miles northwest of Las Vegas, is the only site in the country being studied as a permanent repository for the high-level nuclear waste produced by commercial power plants and defense activities.

The NRC study is reported in Science magazine, which hits newsstands today.

The study's chief geologist, Brian Wernicke of the California Institute of Technology in Pasadena, said researchers were surprised at how fast the surface around the mountain moved during a seven-year study. Imperceptible to anyone except scientists with high-tech sensors, the Earth's surface is constantly moving.

In seismically active zones, such as Yucca Mountain, the Earth is apt to move at a faster rate. Where ground moves more rapidly, there is a greater chance of earthquakes or volcanic eruptions, geologists have learned. Either an earthquake or eruption could result in crushing any containers within Yucca Mountain.

Ground motion, tracked by satellites, suggests that the Yucca Mountain site could enter a period of intensified earthquake or volcanic activity within the next thousand years, the study says. This is because data suggests that the ground around Yucca Mountain is actually moving at a rate 10 times faster than originally thought.

Years ago, the Environmental Protection Agency ruled that any site that would be stable for 10,000 years would be appropriate for a high-level nuclear waste dump. Now, however, this latest data shows that the ground around Yucca can be predicted to be stable only over the next thousand years.

In a telephone interview yesterday, Wernicke said he and fellow scientists participating in the study were "shocked" at the latest data.

Wernicke and James Davis of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., agreed that scientists have underestimated the hazards at Yucca Mountain.

Despite this latest finding, work at Yucca Mountain, preparing it for use as a nuclear dump, will continue at least until this study can be confirmed. The study's methods for reaching its conclusion will be examined and duplicated and the same results will have to be achieved in order for the findings to hold up, Wernicke said.

A 5.6 magnitude earthquake in the area of Yucca Mountain in 1992 shows that tremblers happen there, Wernicke said. Bare Mountain, west of Yucca Mountain, experienced a 6 to 7 magnitude quake within the last 100,000 years, scientists say.

Another reason for ground movement at Yucca could be hot magma flowing beneath the crust, Wernicke said.

Defense Department satellites tracked the movement at Yucca Mountain for the study since 1991. Wernicke said none of the eight other scientists on the team expected to see the crust move.

"We definitely believe we have seen the motions and they are definitely much faster than predicted," he said.

Wernicke said the new hazards raise concern for licensing the mountain as a nuclear waste dump by the Nuclear Regulatory Commission. The NRC and the National Science Foundation funded this study. The NRC could begin considering a license application from the DOE by the year 2002.

"We better understand all of this before we start putting waste in there," Wernicke said.

Tim Sullivan, a leading Energy Department geologist and manager at the Yucca Mountain Project, said the study will be evaluated to see if the results affect DOE's current work. A government assessment has already estimated a very low risk of either an earthquake or volcano.

Bruce Crowe, a DOE Los Alamos National Laboratory geologist in Albuquerque, N.M., urged scientists to review the study's results carefully.

But Wernicke said the government should ring Yucca Mountain with the satellite network. That way, scientists would know in two years whether this study's results are accurate, he said. Between Reno and Salt Lake City 18 satellite stations operate now.

"It would cost only hundreds of thousands of dollars and we'd know something definite in two to three years," Wernicke said.

Gov. Bob Miller suggested the DOE and Congress should start looking for other locations to bury the nation's high-level nuclear waste. "It seems like there is a never-ending trail of evidence that Yucca Mountain is unsuitable for permanently storing nuclear waste," he said.

"There was an earthquake at the site a few years ago and there was substantial damage done, but no matter what the realities are, politics seem to take higher precedence," Miller said.

The Nevada congressional delegation praised the report and remained unanimously opposed to nuclear waste coming to Nevada.

Sen. Richard Bryan, D-Nev., said the study adds to a list of problems discovered at Yucca Mountain. "The suggestion that scientists likely will not be able to provide adequate predictions is of grave concern to me," he said.

"The biggest question for me is whether the Department of Energy will pay attention to this latest report or sweep it under the rug along with the rest of the scientific reports and analyses which could lead to the conclusion that Yucca Mountain doesn't fit the bill," Bryan said.

The study says there is an increased risk from an earthquake at Yucca Mountain, said Sen. Harry Reid, D-Nev. "It indicates to me that the DOE's science has not been good," he said.

Rep. John Ensign, R-Nev., suggested the DOE start looking at salt caverns or deep clays in Texas. "We've been saying all along that, first of all, Yucca Mountain is unstable," he said. "Politics won out over science."

Rep. Jim Gibbons, R-Nev., said he welcomed the study. "It gives great credibility to those of us who believe the site does not meet the qualifications set out by the Department of Energy," he said.