Uranium workers at the Paducah Gaseous Diffusion plant in Kentucky participated in dangerous experiments and were exposed to harmful levels of the radioactive element in the 1950s, according to The Courier-Journal. But what type of health hazards did the plant pose to the public over 38 years?
In a draft report by the Department of Energy (DOE), obtained by The Courier-Journal on Sunday, the plant estimated that more than 132,000 pounds of uranium (66 tons) were released into the air between 1952 and 1990.
DOE noted in its report that it could not determine how those amounts were calculated.
In fact, some employees told investigators they under-reported release amounts by as much as a factor of 5.
Vast amounts of uranium-contaminated smoke, steam and gas were emitted from stacks into the open air -- sometimes secretly, in what employees called "midnight negatives."
There was no monitoring of stack emissions until 1975.
According to one list the department found, there were 15 accidental releases to the atmosphere that each involved more than 50 pounds of uranium hexaflouride.
Another list revealed 69 "probable airborne releases," each involving more than 10 pounds of uranium.
"No evidence could be found that any of the accidental releases were analyzed using a meteorological model for assessing the acute dose to the public," the report says.
The Courier-Journal also reported that there have been some unusual releases of toxic gases.
Several current and former workers told investigators that blue flames 10 inches high have appeared on the surface of a classified landfill after heavy rain.
The report did not say what that might indicate.
Likewise, other radioactive materials would have been released into the atmosphere, but the investigators could find no numbers for such emissions.
Based on the fact that releases inside the process building were a constant problem, the report says " it is apparent that past estimates of public dose have a questionable level of accuracy and conservatism."