IAEA Safeguards During Plutonium Stabilization at Hanford’s Plutonium Finishing Plant

The Vault at the Plutonium Finishing Plan (PFP) became subject to the International Atomic Energy Agency (IAEA) safeguards beginning in 1994 as part of the U.S. excess fissile material program. The inventory needed to be stabilized and repackaged for long-term storage to comply with Defense Nuclear Facility Safety Board Recommendation 94-1. In 1998, the United States began negotiations with IAEA to develop methods to maintain safeguards during stabilization and repackaging of this material. The Design Information Questionnaire was revised and submitted to the IAEA in 2002 describing modification to the facility to accommodate the stabilization process line. The operation plan for 2003 was submitted describing the proposed schedules for removing materials for stabilization. Stabilization and repackaging activities for the safeguarded plutonium began in January 2003 and were completed in December 2003. The stabilization was completed in five phases. IAEA containment and surveillance measures were maintained until the material was removed by phase for stabilization and repackaging. Following placement of the repackaged material into the storage vault, the IAEA conducted inventory change verification measurements, and re-established containment and surveillance. Plant activities and the impacts on operations are described.