For almost 50 years, managers at the nuclear weapons plant with the nation's largest concentration of radioactive waste, in Hanford, Wash., steadfastly maintained that leaks from underground tanks were insignificant because the radioactive material would be trapped by the surrounding soil. But they now admit that they were wrong.
After nearly a million gallons of waste that the Energy Department does not know how to clean up has leaked into the ground, the department belatedly acknowledged that it needs to know more about how plutonium moves through the soil at the plant in the desert along the Columbia River. It hopes to have a strategy by October for how to study the problem, and then amend its clean-up plans for the Hanford nuclear reservation in central Washington. The department will also study whether some recent remedies, based on its mistaken assumption, have actually made things worse.
But experts, including some in the department, are focusing on another but perhaps more troubling problem: How did the department avoid this obvious question for so long and does it mean that it is not as competent an environmental steward as it has portrayed itself to be?
A General Accounting Office report scheduled for release on Monday cites warnings to the Energy Department dating to 1989 that it needed to pay closer attention to the issue. As late as last July, an employee at the plant for 20 years was dismissed by a contractor for raising the issue too vigorously, according to a Labor Department ruling.
In hindsight, even the department publicly acknowledges that it erred in not sufficiently studying the soil, which is called the vadose zone, the relatively dry soil above the water table.
``There has not been enough science for vadose zone assessment,'' Ernest Moniz, the Under Secretary of Energy, said in an interview.
The reason that the department never studied the problem adequately, it now appears, is that it did not want to know.
``There's no doubt there was little enthusiasm for this,'' Dr. Moniz said.
The Hanford reservation has not produced plutonium, the basic fuel of nuclear bombs, since 1987. About 54 million gallons of radioactive waste, in liquid, sludge and dried salt forms, is stored at Hanford in 177 underground tanks. Of those, 149 are made of a single shell of steel, and about 68 have leaked, releasing about 900,000 gallons into the soil. The oldest tanks are more than 50 years old, and all the single-shell tanks are expected to leak eventually.
The department had said for decades that no waste from the tanks would reach the ground water in the next 10,000 years at least, but it is already there.
Local Energy Department officials reluctantly acknowledged the presence of tank waste in the ground water only in November 1997, based on work performed by two whistle-blowers who had previously been penalized for making safety complaints.
At the Washington State Department of Ecology, Suzanne L. Dahl, a hydrogeologist who is the tank waste project manager, said the Energy Department's position was, in part, simply wishful thinking. After finding evidence that contamination in underground water was moving toward the Columbia River, which is only a few miles from the most distant tank, her department argued long and hard two years ago that the Energy Department should pursue more vigorous studies, but found the department very hard to persuade.
``It was a little bit of burying their heads in the sand and hoping it wouldn't get there, hoping they wouldn't have to deal with it yet,'' she said.
Now, according to the General Accounting Office, the Congressional auditing agency, these gaps in knowledge threaten the cleanup. For example, the soil at the surface has become contaminated, so engineers decided to spread clean gravel on top to reduce the exposure of workers. But the gravel increased the flow of rainwater through the contaminated dirt, thus washing radioactivity toward the Columbia River even faster, experts say. Without the gravel, surface dirt or plants might have absorbed the water and allowed it to evaporate, without percolating through the soil.
The long-term plan is to pump wastes, mostly sludges and salts, from the tanks into a factory where they will be mixed with glass, to immobilize them. The Energy Department estimates the cost to process the wastes into solids -- which will not make them any less toxic, just less mobile -- at about $50 billion. The job would take decades at least, and its start and the cleanup of the contaminated soil will probably have to be delayed until more is known about the soil.
The plan for cleaning the wastes out of the tanks is to sluice them out with high-pressure water hoses. But if the tanks leak and the soil is permeable, this strategy will make matters worse, experts say. So little is known that there is no basis for a decision, according to the General Accounting Office and others.
The department's failure to study the issue properly is shaking outsiders' faith in the department, which has been trying to portray itself as a competent environmental steward.
``The Department of Energy has been sticking its head in the contaminated sand, for years, years,'' said Senator Ron Wyden, a Democrat from Oregon, just across the Columbia River. ''The department's official story was that contamination stopped a few feet beneath the tanks, and even when they got samples from the bore holes drilled near the tanks that showed contamination at much deeper levels, they argued that the contamination could have been pushed down by the drilling,'' he said.
Outside experts, chosen by the Energy Department, said in January that the department was still relying on outdated models of the soil, and Mr. Wyden complained, ``the Department of Energy just keeps doing business as usual, excuses as usual.''
The General Accounting Office study was requested by Senator Wyden and Senator John Glenn, Democrat of Ohio, who began investigating Hanford and other weapons plants in the mid-1980's when he was the chairman of the Government Operations Committee. In a statement, Mr. Glenn said that six years ago he had urged more vigorous monitoring of contamination through the soil and that the result was only more promises. ``After all this inexcusable delay, continued failure to plan and implement an assessment program will raise serious questions about whether D.O.E. should remain in charge of this program,'' he said.
Management at the site, however, probably is not threatened by anger
from Washington. Dr. Moniz said that on a trip to Hanford in January he
had explored the problem and had found that ''the vadose zone is
intellectually virgin territory.'' But he did not place blame. ''I did
not attempt any human archeology'' to trace the source of the problem.
Copyright © 1998 New York Times