Abstract
This article describes work performed on behalf of the US Department of Energy (DOE) to disposition 467 government-owned, sealed californium-252 (Cf252) sources located at 52 academic and government research sites. These sources are the legacy of the DOE Cf252 Loan/Lease Program, which operated from the late 1960s until 2008, when the loan program closed abruptly. Although the DOE took decades to fabricate and distribute the sources, best safety and nuclear accountability practices demanded retrieval or disposition of all loaned sources as soon as achievable after the loan program was closed. An adaptable disposition approach was developed, and disposition of the sources was pursued. The approach involved a combination of source retrievals, disposal actions, and source ownership transfers. A new shielded shipping container was designed and deployed to aid in source retrievals. In a couple cases, incomplete source fabrication and shipping records prevented shipment, and those sources were left indefinitely with the customer in a safe configuration. All the sources in the inventory were safely dispositioned in some way, and lessons learned from this effort are provided.