CARLSBAD, N.M. -- Officials are monitoring the presence of airborne radiation at southeastern New Mexico's nuclear waste repository.
The U.S. Department of Energy says personnel are on-site Saturday to assess what officials are calling a "possible radiological event" at the Waste Isolation Pilot Plant.
According to the DOE, an air monitor detected radiation on the plant's underground levels around 11:30 p.m. Friday.
Officials say no employees were working underground at the time, and workers on the surface have been sheltered in place as a precaution.
They say nobody has been found to be contaminated.
WIPP is the nation's first and only deep geological nuclear waste repository. It takes plutonium-contaminated waste from Los Alamos National Laboratory and other federal nuclear projects.
The incident comes 10 days after an underground truck fire at the plant prompted an evacuation.