Department of Energy officials deny this, but it's likely that a criticality -- a nuclear chain reaction -- occurred during the 1957 fire.... Elements such as strontium-90 and cesium-135 never occur except in the case of a nuclear chain reaction. Based on soil and water testing completed decades later that detected the presence of these elements, some experts -- despite the government's insistence that there has never been a criticality at Rocky Flats -- believe that a criticality accident producing various fission products may have occurred on September 11, 1957.
But the worst thing about the fire was that no one -- except for officials with the Department of Energy and Rocky Flats (then operated by Dow Chemical) -- knew about it. There was no public evacuation, no warning, nothing in the press. Local citizens had no idea. This fire was deliberately hidden from public view. People were exposed to plutonium and other contaminants without their knowledge, although officials at the plant were aware of what was going on.
COHEN: How long did it take for the government, and the private entities involved, to admit to what happened on September 11, 1957? When did it dawn on people, in the area and elsewhere, that this great event had occurred?
IVERSEN: Thirteen years passed before the public began to learn that this fire occurred and had contaminated the Denver metro area -- and it took another devastating fire to force the government and the private companies that operated Rocky Flats to reveal the truth.
Following the Mother's Day fire in 1969, an independent group of scientists conducted off-site testing and found plutonium contamination in areas near Rocky Flats to be 400 to 1,500 times higher than normal (i.e., average background concentrations from global fallout). A biochemist at the University of Colorado noted, "That is the highest ever measured near an urban area, including the city of Nagasaki." The Atomic Energy Commission then conducted its own off-site study, and that study confirmed plutonium contamination as far as thirty miles from the plant.
At that point, officials were forced to admit to off-site plutonium contamination as well as the fact that they had been aware of it for years, although local residents had not been informed or warned. The biggest surprise, however, was the admission that the contamination did not come from the 1969 fire, as had been assumed, but primarily from the devastating 1957 fire. Another source of long-term contamination was the 903 Pad, where more than 5,000 barrels stood out in the open for 11 years and leaked radioactive material into the soil and groundwater.
Even today, many people in Colorado don't know about these fires, particularly the 1957 fire, and its long-term danger.
COHEN: Has there ever been a calculation of the deaths and injuries caused by Rocky Flats, an accounting, official or otherwise, of the human toll upon the residents in the region?