A former nuclear waste dump in Armstrong County will now be patrolled by guards from the federal Department of Homeland Security.

Officials said they're rethinking their cleanup plans for the site after finding more complex nuclear material than expected.

Our news exchange partners at TribLIVE said neither the Army Corps of Engineers nor the Nuclear Regulatory Commission would say what nuclear material was found at the site.

The Army Corps of Engineers manages the cleanup.

Homeland security officials said the additional security measures were put in place at the request of the Army Corps of Engineers.

It was not related to a specific threat in the area.

The nuclear waste dump was the former Nuclear Materials and Equipment Corp from about 1960 to the early 1970s.