WIPPALBUQUERQUE, N.M. (AP) — Thirteen workers were exposed to radiation during a recent leak at the nation’s underground nuclear waste dump in southeastern New Mexico, according to the results of preliminary tests announced Wednesday. The U.S. Department of Energy and the contractor that runs the Waste Isolation Pilot Project said in a joint news release that they have notified the workers of the positive results and will do further testing. They declined to comment further until a news conference Thursday afternoon. “It is important to note that these are initial sample results,” the statement said. “These employees, both federal and contractor, will be asked to provide additional samples in order to fully determine the extent of any exposure.” More