Testing following a radiation alarm at the Department of Energy's New Mexico waste repository has indicated that 13 workers were exposed to radionuclides.
All employees were above ground when safety systems initiated at the repository Feb. 14; and all cleared a check for external contamination. But later bioassay results indicated some workers might have accumulated internal doses from inhalation, according to the DOE. They include DOE employees and contractors on duty that night. Their total accumulated doses won't be known immediately because measuring them requires multiple biological samples over three or more weeks. In the meantime, the sampling program is also monitoring employees who worked Feb. 15, those considered at greater risk of exposure, and any other employees who ask to participate.
"It is premature to speculate on the health effects of these preliminary results, or any treatment that may be needed. However, on-site sampling and surveys and environmental monitoring to date continue to support National Atmospheric Release Advisory Center modeling, which indicates that airborne contamination was likely at very low levels," DOE Carlsbad field office manager Jose R. Franco wrote in an open letter to the surrounding community.
The Waste Isolation Pilot Plant stores transuranic defense waste in tunnels carved from a layer of salt a half mile beneath the New Mexico desert. It was closed to deliveries after a truck fire underground earlier this month. The cause of the radiation alarm the following week remains under investigation, and samples taken aboveground near the repository recently showed traces of americium and plutonium in the air.