This is a Sources Sought notice, not a solicitation, to determine if other qualified sources exist for a proposed sole-source procurement. The Defense Threat Reduction Agency (DTRA) intends to award a firm-fixed-price contract to Eckert & Ziegler Isotope Products, Inc. for ten sealed sources of Cobalt-60 radioisotopes. Interested parties have 15 days from the synopsis publication date to submit written evidence of their capabilities to potentially justify a competitive procurement. The notice does not specify a budget or a location for performance.