Radioactive plutonium and americium were detected in air samples collected on Thursday, June 8, 2017 at the Hanford nuclear reservation in Washington, US, state officials said Tuesday, August 8.
According to Hanford officials, State of Washington's Department of Health's (DOH) workers analyzed samples taken on June 8 and detected low levels of contamination near the Rattlesnake Barricade, just off of public Highway 240, where workers enter the secure area of the site.
The samples were collected following an airborne release of radioactive particles during the demolition of one part of the Plutonium Finishing Plant (PFP), a highly contaminated facility. However, the investigation has not conclusively linked the contamination to the PFP demolition, located at least 4.8 km (3 miles) from the Rattlesnake Barricade.
At the time, about 350 employees took cover inside the facility as a precaution after an air monitor alarmed. The event happened just one month after widely reported tunnel collapse at Hanford's Plutonium Uranium Extraction Plant (PUREX) full of highly contaminated materials.
DOH said analysis results for the air samples were received Monday, August 7, adding that the contamination levels were very low and do not pose a health risk. Air samples collected downwind of the PFP at the Columbia River, which is accessible to the public, had no contamination.
"The level is interesting from a regulatory point of view, but is not a health risk to the public," said Mike Priddy, manager of the Environmental Sciences Section of the Department of Health, as reported by the Tri-city Herald.
The amount of americium detected is reportedly about three times the limit allowed by state air quality standards, but the standard is based on an average amount over 365 days for someone living there and growing food there, according to Department of Health officials.
The amount of plutonium found was too small to exceed air quality standards, according to the Department of Health.
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