INEEL defends buried waste cleanup program

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By GREG MOORE
Express Staff Writer

A truck dumps barrels of waste, which may include radioactive or chemically hazardous materials, into a pit at the Idaho National Engineering and Environmental Laboratory in 1969.

ARCO-Officials at the Idaho National Engineering and Environmental Laboratory (INEEL) last week said construction of a proposed mixed-waste treatment plant there would not slow their efforts to clean up buried radioactive and chemical wastes.

The proposed plant, which would include an incinerator, is designed to put 1.8 million cubic feet of mixed nuclear and chemical waste now stored above ground into a form suitable for permanent disposal at the Waste Isolation Pilot Plant (WIPP) in New Mexico.

Critics of the plant have argued that the Department of Energy should first clean up the more dangerous buried wastes, some of which have been stored there since the 1950s and which are leaking into the ground above the Snake River aquifer.

"There’s no reason why we can’t do both at the same time," DOE spokesman Brad Bugger said last Wednesday during a tour of the site organized by the Snake River Alliance nuclear activist group. "Doing one is not taking away from the other."

In fact, Bugger said, the treatment plan might be able to treat some of the buried wastes as well, though that would require changes in INEEL’s permits.

The wastes were buried between 1954 and 1970 in 20 pits and 58 trenches that cover 12 acres. Much of the material is "transuranic" waste, meaning it is contaminated with plutonium, generated during nuclear weapons production at the Rocky Flats plant in Colorado.

The waste was buried for supposedly permanent storage at a time when standards for dealing with radioactive and chemical materials were far more lax than they are now. How to now make up for that laxity has become one of the DOE’s biggest headaches at the lab.

An attempt to deal with the waste buried in one of the pits, known as Pit 9, was begun in 1995 but abandoned last year after the subcontractor, Lockheed Martin, ran into unexpected technical problems. Its agreement with the DOE was terminated.

The buried wastes pose both radioactive and chemical hazards. In an interview, Bugger said the DOE has found traces of americium, a daughter product of plutonium, in the 600-foot-deep aquifer. However, he said scientists are uncertain whether the material came from the buried wastes or from airborne fallout from nuclear weapons tests in Nevada.

"They’re just isolated hits," Bugger said. "We’re not finding a pattern."

During Wednesday’s tour, buried waste area project manager Alan Jines said a major hazard posed by the waste is its leakage of solvents, particularly carbon tetrachloride.

"They’re very mobile, they’re hazardous to your health and they are moving," Jines said.

He said about 80,000 gallons of the chemical has leaked into the soil beneath the pits, though 90 percent of that has evaporated back up. Even so, Bugger said in an interview, solvents have been detected in the aquifer.

Jines said the DOE is preparing to drill deeper wells to better determine the extent of chemical migration, and to pump out what it can.

Dr. Michael Watson, senior toxicologist with the U.S. Environmental Protection Agency in Seattle, said the main hazard posed by carbon tetrachloride is that it causes liver damage. He said it has also been shown to cause cancer in animals, but that it is a matter of debate whether it is carcinogenic to humans.

Watson said the chemical is not likely to degrade once in the groundwater, but much of it would do so after reaching surface water. He said acceptable exposure to carbon tetrachloride through drinking is only a few parts per billion.

Jines said partial retrieval of some of the buried drums containing the wastes, carried out several times during the 1970s, showed that many were broken, rusted or leaking.

"We know the pits are in much worse shape now than when those excavations were done," he added.

Jines said his team is researching the various methods available to deal with the buried waste. He said those fall into two categories—retrieval of the wastes and treating them above ground for permanent disposal elsewhere; and "in situ" treatment.

Any retrieval method, he said, would have to be done in a contained area and use remote mechanical means of extraction and repackaging.

Treating the waste "in situ" would involve removing the solvents and injecting a substance to create a block of solid material around the radioactive material.

"If water can’t get to the radionuclides, they can’t move," Jines said.

Jines presented three possible "in situ" procedures. The first would involve injecting grout in 20-inch-diameter columns that would form one large block.

The second, called vitrification, would involve inserting carbon rods that would be melted by electricity. During that process, the solvents would be evaporated and the gases contained and neutralized.

The third process, called thermal desorption, would burn off the solvents, which would then be contained.

In an interview, Snake River Alliance research associate Steve Hopkins expressed skepticism about any of the "in-situ" methods, calling them unproven technologies. He said the only experiment with vitrification in the United States, carried out at Oak Ridge, Tenn, in 1997, resulted in a sudden, explosive swelling of the ground by about a foot.

"It’s never been applied to an actual burial ground," Hopkins said.

Hopkins said his organization supports research into the "in-situ" methods, but believes that retrieval would be the best means to ensure containment of the wastes.

"As a result of the (political) pressure that’s been applied, they’re taking retrieval of the wastes more seriously," Hopkins contended.

In his presentation, Jines addressed the claim by the Snake River Alliance that money spent on the proposed mixed waste treatment plant would be money deleted from the effort to deal with the buried wastes.

He said the need to move forward carefully and develop new procedures limits the speed at which the DOE can proceed with that project no matter how much money is made available. In fact, Jines said, "I would argue that letting a little time go by has allowed us to develop new technologies to treat the waste."

Snake River Alliance leaders remained skeptical of that argument.

"After all that money is spent on the (mixed waste) treatment facility, that could very much affect the choice of a treatment program for the buried waste," Hopkins said.

Jines said that his team’s first mission is to better determine what the buried waste contains. Workers began to do that for Pit 9 by drilling to remove cores from various points in the pit.

However, a question arose in June as to whether the drilling might cause the mixture of potassium and sodium nitrates and organic chemicals to explode or ignite. He said a commission formed to answer that question is scheduled to release its report this week, and he hopes to begin drilling again on Oct. 30.

Jines said that even such a minor technical snafu caused "a full year’s delay in our ability to drive a pipe into the ground," pointing out that an unavoidable slow pace, not lack of funds, is driving the cleanup schedule.

Jines said that under a Federal Facilities Agreement, signed among the DOE, the state of Idaho and the U.S. Environmental Protection Agency, the DOE must come up with a draft decision on proposed treatment methods for the buried wastes by December 2002. However, he said, he has proposed that that deadline be delayed four years.

Bugger said drawing up a proposed plan will involve a public comment process that will include public hearings.

Asked how long the cleanup is expected to take, Bugger said, "It’s still too early to even make a guess about that. This is a tricky business."