Posted at: 05/13/2014 8:01 AM
Updated at: 05/13/2014 3:14 PM
By: The Associated Press
CARLSBAD, N.M. (AP) - Investigators trying to determine what caused a radiation release at the federal government's underground nuclear waste repository in southern New Mexico have spotted melted plastic and rubber on some drums and boxes of waste.
They were able to take photographs of the melted material during their most recent trip into the Waste Isolation Pilot Plant near Carlsbad.
WIPP recovery officials say the melted material indicates there was some kind of heat generated in the room where the waste stored.
The radiation release in February exposed some workers and halted all shipments to the repository.
Officials with the U.S. Department of Energy have theorized that the release could have been caused by a chemical reaction in some of the drums. They're also looking at other possibilities.
(Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)