Plutonium and americium have been found in high-volume air samples collected June 8 by Washington state at the Hanford Site’s Rattlesnake Barricade.
On June 8, Hanford personnel were ordered to take cover about 3 miles away at the Plutonium Finishing Plant after alarms for airborne contamination sounded during demolition of the plant’s Plutonium Reclamation Facility.
The state Department of Health received analysis results late Monday, and a memo was distributed Tuesday to Hanford workers telling them low levels of contamination had been detected. “The level is interesting from a regulatory point of view, but is not a health risk,” said Mike Priddy, manager of the Environmental Sciences Section of the Health Department’s Office of Radiation Protection.
The detection of airborne contamination at the Rattlesnake Barricade — where workers enter the secure area of Hanford from public Highway 240 — was unexpected, state and Department of Energy officials said at a Hanford Advisory Board committee meeting Tuesday. The wind was not blowing toward the barricade from the Plutonium Finishing Plant on June 8. The Health Department also found no contamination in air samples collected downwind of the plant at the Columbia River on June 8, state officials said.
“We are taking it seriously,” said Tom Teynor, federal project director for the plant. The Department of Energy and Department of Health are just beginning to investigate the findings at the Rattlesnake Barricade, and officials for both agencies said it is too soon to definitively conclude that the contamination originated at the Plutonium Finishing Plant.
When airborne contamination was detected June 8, no contamination was found on the skin or clothing of Hanford workers at the plant. However, workers were offered bioassay kits to check for internal contamination as a precaution. A small number of the first 65 bioassay tests analyzed have been positive for worker internal contamination, according to DOE and Hanford cleanup contractor CH2M Hill Plateau Remediation Co.
CH2M characterized the positive results as showing a dose of 1 millirem or less over 50 years, calling it significantly less than a typical chest X-Ray.
