Investigation Probes Worker Radiation Exposure at Rocky Flats

GOLDEN, Colorado, December 7, 2000 (ENS) - Investigators are still trying to determine how 10 workers were exposed to radiation in recent weeks at the Rocky Flats Environmental Technology Site, a former U.S. government nuclear weapons manufacturing facility located 15 miles northwest of Denver, Colorado.

Rocky Flats

Rocky Flats Nuclear Facility (Photos courtesy U.S. Dept. of Energy)
The workers are employed by the Kaiser-Hill Company, the private firm contracted to decommission the mothballed nuclear weapons plant owned by the U.S. Department of Energy (DOE).

Biological tests are still being performed on the workers, but preliminary results indicate that they were exposed to less than 20 percent of the allowable annual radioactive dose of 5,000 millirem, said Kaiser-Hill spokeswoman Jennifer Thompson.

"We're expecting all of the exposures to be less than 1,000 millirem," said Thompson.

None of the workers tested positive for radioactivity in lung scans, which can detect exposures at levels above 1,000 millirem, Thompson explained. However, low levels of radioactive plutonium did show up in the workers' fecal samples, which can be analyzed with greater precision, she said.

In Colorado, people are exposed to about 400 millirem of "background" radiation every year, Thompson noted.

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Production area in building 771
The workers were exposed while working in building 771, where plutonium used in the nuclear weapons manufacturing process was recovered so it could be used again. The building once contained thousands of liters of plutonium solutions stored in nearly 200 tanks and 30 miles of tangled piping, which earned it the dubious honor of being the most vulnerable facility in the DOE complex in 1994.

Workers began decontaminating and decommissioning Building 771 two years ago. Workers must don air purifying respirators, two sets of booties and three pairs of specially designed gloves to disassemble the building's industrial equipment, which is contaminated with plutonium, nitric acid, hydrochloric acid, hydrogen fluoride and other dangerous materials.

Decommissioning work in the building remains suspended while investigators continue to look for the source of the contamination that affected the workers, Thompson said.

"We don't have an event to tie this to, so we're still investigating the source," she said. "We won't be able to return to work until we can do it safely. We don't have an exact date when that will happen."

Kaiser-Hill investigators have located 15 new contaminated areas within the 147,900 square foot building that had not been previously identified, Thompson said. But those areas are not suspected to have caused the exposure that the workers suffered, she explained.

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One of the control rooms in building 771
Thompson said that the incidents have not to date generated any safety related violations from the DOE. Kaiser-Hill is subject to fines and sanctions if it fails to meet the safety and performance measures stipulated in its DOE contract.

"At this point [DOE} is more concerned with the investigation that's currently ongoing," Thompson said. "Any decisions [about violations] would be made at a later date."

Last month, the DOE levied a $250,000 performance penalty against Kaiser-Hill for failing to take proper precautions during a number of potentially hazardous electrical work projects. Since 1996, the company has been assessed more than $700,000 in safety related fines.

The DOE and Kaiser-Hill hope to have the Rocky Flats site completely cleaned up and closed down by December 15, 2006. However, a host of studies - including one by the General Accounting Office, the investigative arm of the U.S. Congress - maintain that the closure project will take much longer.

Legislation is pending on Capitol Hill that would transform the 6,000 acre Rocky Flats site into a federal wildlife refuge after it closes. The measure is sponsored by Colorado Senator Wayne Allard, a Republican, and Congressman Mark Udall, a Democrat.

Building 771 is slated to be demolished by 2004. According to Thompson, workers are making "really good progress" in the building, having already removed more than 125 of the building's 217 contaminated welded stainless steel gloveboxes.

But the building will pose a special challenge to workers: it contains at least one so-called "Infinity Room," where contamination is so high that it could not be accurately measured when its door was welded shut in the early 1970s.

More information about Rocky Flats is available online at: http://www.rfets.gov.