Year
2009
Abstract
The shut down of United States (U.S.) nuclear-weapons production activities in the early 1990s left large quantities of nuclear materials throughout the U. S. Department of Energy (DOE) complex in forms not intended for long-term storage. In May 1994, the Defense Nuclear Facilities Safety Board (DNFSB) issued Recommendation 94-13, which called for the stabilization and disposition of “thousands of containers of plutonium-bearing liquids and solids” in the DOE complex, including LANL in the nuclear-weapons-manufacturing pipeline when manufacturing ended. This resulted in the development of the 3013 standard with container requirements for long term storage (up to 50 years). A follow on was the Criteria for Interim Storage of Plutonium Bearing Materials, Charles B. Curtis, in 1996 to address storage other than the 3013 standard for shorter time frames. In January 2000, the DNFSB issued Recommendation 2000-14, which stated the need for LANL to repackage “about one ton of plutonium metal and oxide,” declared excess to Defense Program (DP) needs. The DNFSB recommended that LANL “stabilize and seal within welded containers with an inert atmosphere the plutonium oxides… which are not yet in states conforming to the long-term storage envisaged by DOE-STD-3013,” and that they “…enclose existing and newly-generated legacy plutonium metal in sealed containers with an inert atmosphere,” and “remediate and/or safely store the various residues.” Recommendation 2000-1, while adding to the number of items needing remediation, also reiterated the need to address remaining items from 1994-1 in a timely fashion. Since timetables slipped, the DNFSB recommended that the Complex “prioritize and schedule tasks according to the consideration of risks.” In March 2005, the DNFSB issued Recommendation 2005-15. This recommendation addresses the need for a consistent set of criteria across the DOE complex for the interim storage of nuclear material packaged outside an engineered barrier. The Department of Energy (DOE) approved and issued on March 7, 2008, DOE M 441.1-1, Nuclear Material Packaging Manual 1 [hereafter referred to as Manual] to address this recommendation, and a Prioritization Methodology8 as a complex-wide requirement for the packaging of nuclear material outside an engineered barrier. The Manual establishes “technically justified criteria” for packages in order to ensure safe interim storage and handling outside an engineered barrier. The Prioritization Methodology establishes a risk-based procedure for identifying the order to repackage that would most efficiently reduce the overall risk. It is a logical extension of the work performed to meet the two earlier DNFSB recommendations to include all materials stored outside of engineered barriers, i.e., not just excess materials.