Seven nuclear bombs' worth of plutonium escaped into air ducts at the Rocky Flats weapons plant near Denver over the 38 years of the plant's operation, Federal officials said yesterday.
Officials of the Federal Department of Energy said workers had detected 28 kilograms, or about 62 pounds, in the ducts, more than twice the amount of plutonium they had been expected to find. Plutonium is so toxic that it is usually accounted for in quantities expressed in grams or thousandths of a kilogram.
The search was undertaken after an independent study found last October that enough plutonium had accumulated in the ducts to raise the possibility of an accidental nuclear reaction. The experts who undertook the study said that the plutonium would not escape from the buildings but that about 12 kilograms would be found in the ducts.
Energy Department officials said the plutonium was contained in exhaust ducts and therefore was not in a position to harm workers within the buildings. And they said filters kept it from escaping into the air outside.
Critics of the Government's weapons complex said the discovery indicated worse mechanical and managerial troubles at the plant than had previously come to light. Rocky Flats has been closed since December to correct the problems.
The plant makes nuclear triggers for hydrogen bombs.
"This is a very substantial quantity of plutonium that was simply not accounted for," said Dan W. Reicher of the Natural Resources Defense Council, a Washington-based group that has repeatedly sued the Government to force safety and environmental improvements. "They should have been keeping track of this plutonium for both security and health reasons."
Critics of the Department say the fact that such a quantity could be found without the Government's knowing that it was missing casts doubt on its system of keeping track of the the material.
They say that what they view as lax accounting leaves open the possibility that some plutonium may have been diverted by terrorists or foreign agents. The Government says there is no evidence that that has happened.
It is not clear if more plutonium is unaccounted for and waiting to be discovered within the plant. The Federal Government says such information is classified.
Leo P. Duffy, director of Waste Management and Environmental Restoration at the Department of Energy in Washington, said the material in the ducts at Rocky Flats represented the residues of 38 years of operation and was a very small fraction of the amount of plutonium that the plant has handled.
The material, Mr. Duffy said, was found spread over 6,000 feet of pipe and was not in a concentration sufficient to allow an inadvertent nuclear reaction. The Department has taken steps to prevent more plutonium from leaking, he said. But he acknowledged, "None of this is a satisfactory way of running an operation."
The disclosure of the quantity of plutonium was first made yesterday by a plant official to Melinda Kassen, a lawyer with the Environmental Defense Fund in Boulder, Colo., near the plant.
Ms. Kassen, a member of the Rocky Flats Monitoring Council, a quasi-governmental organization established by Representative David E. Skaggs and Governor Roy Romer, had asked plant officials at a meeting the previous day if they had completed the study they promised last October. She said that she was told that the survey had been completed but that the number was being withheld.
Yesterday, she said, she was told that the quantity was 28 kilograms, a figure the Energy Department later confirmed.
Ms. Kassen said it was evident that the plutonium had escaped into the ducts because for years, as filters became clogged and automatically closed operations, workers had punched holes in them so the air, although contaminated, could pass through.
The plutonium in the air, the Energy Department says, attached itself to the exhaust ducts or was captured by subsequent filters.
The ducts and filters are connected to "glove boxes," enclosed spaces into which operators can insert their hands in gloves built into the wall. The glove boxes are kept at a slight vacuum, so any leaks draw air in rather than allow plutonium particles out.
Members of the monitoring council have asked whether EG&G Inc., the Wellesley, Mass.-based contractor that took over the Rocky Flats operation in January from the Rockwell International Corp., will modify the boxes before operations resume, she said, and were told that no decision had been made.
Mr. Duffy, in Washington, said that the Department had established training procedures to assure that workers would not bypass the filters and that it had programs to test the filters and determine when they are clogging up.
WASHINGTON, March 28 (AP) -Energy Secretary James D. Watkins strongly hinted today that deployment of Trident 2 ballistic missiles could be delayed next year by problems at the Rocky Flats plant. has been closed since Mr. Watkins said he hoped the plant could resume operation by this summer.
In an appearance before a House Armed Services subcommitee on nuclear weapons production, Mr. Watkins said he could not discuss details, but said, "I can guarantee if we don't move aggressively" to get the weapons production complex back in full operation soon, "there will be severe ramifications."