Updated: 7/28/2008 6:40:31 PM
The Holifield Radioactive Ion Beam Facility (HRIBF, Building 6000) at Oak Ridge National Lab was evacuated Monday morning after a worrisome radiological reading.
The Operational Emergency was declared at 9:33 a.m.
At 5:25 p.m., the Operational Emergency ended.
According to John Shewairy with the Department of Energy, it was declared after a routine reading indicated double the appropriate amount of Cesium 138 - an airborne particulate - inside the building.
Cesium 138 is a byproduct of the processes conducted inside the building.
Recovery operations will continue Tuesday at the HRIBF. Offices and laboratories will re-open normally, but the accelerator won't be restarted until an investigation is complete.
Shewairy says six or eight employees were evaluated onsite for possible radiological exposure. The results of those evaluations are not available. DOE says the event was confined to the HRIBF building, and no danger of contamination exists outside the building.
A response team returned to the building Monday afternoon to get readings on the levels of radiation inside. The one-room lab where the elevated levels were first discovered will be closed for 2-3 days. This is normal for this type of incident.
An operational emergency is the lowest level of emergency for a event at a Department of Energy site without any significant release of hazardous materials.
