An employee inside the building reported a smell around 10:30, Lookofsky said. The eight workers in the building were evacuated. Four others inside an adjacent annex, where trucks are loaded, also were evacuated as a precaution, Lookofsky said. No other buildings were evacuated.
“Our understanding was that there may have been a very, very small release that probably dissipated immediately. There was no visual indication of a leak,” Lookofsky said. “There was no evidence of a leak other than the employee’s word, and we do not doubt that.”
Smell and visibility are the initial signs of a release, Lookofsky said. Uranium hexafluoride, also known as UF6, is mildly radioactive and emits toxic hydrogen fluoride when exposed to moisture in the air.
Radiological surveys of the employees showed no detectable contamination, Lookofsky said. One of four stations inside the building will remain out of operation for a few days while the equipment is tested, she said.
Another reason that plant officials suspect there may not have been a leak is that the automatic alarms inside the building that sound when gas is detected were functioning and remained silent, Lookofsky said.
The three remaining stations inside the building returned to operation at 11:30 a.m.
After detecting the smell, the employee notified co-workers and radioed for emergency support, Lookofsky said. Plant firefighters and 10 employees of the shift emergency squad, who have first-responder training, were dispatched to the building, which is standard practice, Lookofsky said. Several air samples were then taken inside and outside the building.
The tests on equipment are not expected to interrupt work inside the sampling building, Lookofsky said.