A decommissioned medical irradiator containing material that could be used to construct a dirty bomb has been removed from Temple University’s Old Medical School Building by the National Nuclear Security Administration’s Global Threat Reduction Initiative, the agency said yesterday. The irradiator was used for medical research for nearly two decades, but when it was recently decommissioned, the radioactive cesium-137 became attractive material that could be used in a dirty bomb. The NNSA said it worked with Temple University as well as local and state regulators to remove the irradiator from the hospital, where it was transported to a secure location to be prepared for disposal at a federal facility. “This operation is part of NNSA’s broad strategy to keep dangerous nuclear and radiological material safe and secure by enhancing our nation’s security,” NNSA Deputy Administrator for Defense Nuclear Nonproliferation Anne Harrington said in a statement. “This mission demonstrates how NNSA utilizes its unique expertise and technical resources to partner with local communities and other agencies to make our cities safer here and around the world.”