Some workers at a federal uranium processing plant in Kentucky participated in experiments in the 1950s that had them breathing the radioactive element, The Courier-Journal reported Sunday.
Some of the participants at the Paducah Gaseous Diffusion Plant volunteered for the tests, but some may not have been informed of the dangers, according to a draft report by the Department of Energy (DOE) on an investigation of health, safety and environmental problems.
In one experiment, staff members volunteered to breathe a radioactive gas to see how quickly uranium was excreted in their urine, according to the report obtained by The Courier-Journal.
In other tests, a senior staffer drank a solution containing uranium, and at least 14 workers tested the effectiveness of respirators against radioactive dust, gas and smoke, according to the report.
Although the general dangers of radiation were known at the time of the experiments, its interactions with the human body were not entirely understood.
Many believed that uranium dust and byproducts of the enrichment process posed little or no hazard for humans.
The draft report also says wholesale pollution of the air, ground and water around the plant -- in quantities that may have been significantly underreported -- may have exposed residents to radiation.
When asked about the report, DOE officials said only that it was under review.
The Paducah plant has been managed by the department, as well as by predecessor federal agencies and private contractors.
The report details a range of problems at Paducah from 1952 to 1990.
For years, investigators found, workers were not always told of the dangers they faced working with highly toxic radioactive materials. And their families may have been exposed when workers took contaminated clothing home to be laundered.
Vast amounts of uranium-contaminated smoke, steam and gas were vented into the open air -- sometimes secretly in what employees called "midnight negatives."
Inside some buildings, workers were exposed to unplanned releases and leaks of radioactive gases and hazardous chemicals such as hydrofluoric acid, the report said.
The department began its review after a lawsuit by three employees alleged that former plant operators Lockheed Martin Corp. and Martin Marietta Corp. had profited by lying to the government about the extent of environmental pollution and worker exposure to radiation.
The investigators said that although measured exposures to radiation were high by today's standards, total exposures were comparable to those occurring at Defense Department facilities, commercial nuclear power plants and other DOE factories.
However, documents showed that, during the 1950s, 40 to 60 workers sought medical help every four months after exposure to accidental releases of uranium, hydrogen fluoride and fluorine.
In a companion story focusing on a feed mill at the Paducah plant, The Courier-Journal reported that workers were exposed to radiation levels so high it was possible for a worker to be exposed to as much radiation in one day as was then considered safe for an entire year.
The paper cited a newly released report, dated Feb. 21, 1961, that contained data on radiation emissions.
During a typical week, about 60 to 70 men worked round the clock in four shifts in the feed plant, producing fluorine from hydrofluoric acid and combining the lethal gas with uranium powder.
Retired workers said burns were a frequent occurrence. Workers were told that the radiation they were exposed to was no more than what they would get from an X-ray or the sun.
The feed mill was closed in the late 1970s.
Overall, three workers died in plant incidents throughout the 38-year period surveyed.
A fourth worker was so seriously burned that he never returned to work and may have died.
There are two cases of workers' urine testing positive for plutonium in 1953, and two in 1968, in which the skin of two employees showed significant over-exposure to radioactivity.
DOE's report was based on more than 200 interviews with current and former plant employees and officials, as well as on reviews of documents and on-site surveys of some contaminated areas.