Design Life Extension of the SAVY-4000 Series Containers

The DOE Manual, M441.1-1, Nuclear Material Packaging, provides detailed packaging requirements for protecting workers from exposure to nuclear materials stored outside of an approved engineered contamination barrier. The SAVY-4000 Series nuclear material packaging system is a DOE Manual 441.1-1 compliant storage system used at Los Alamos National Laboratory and across the DOE complex as the primary storage system for plutonium-containing materials not in 3013 containers. The SAVY-4000 Series containers have a design life of five (5) years that was established in the SAVY-4000 Series Safety Analysis Report (SAR) . The SAR specifically states that the design life can be extended based on laboratory studies and results from the surveillance program. This report summarizes the technical work from laboratory studies and the Surveillance program relating to the design life of the SAVY Series containers. Accelerated aging studies on the polymer components (O-ring and filter) indicate that 40 years is conservative for conditions that are bounding with respect to temperature, radiation and the combination of temperature and radiation. No change in these components has been seen in surveillance to date. We recommend a design life of 40 years for these components. Observations of general corrosion and corrosion pitting of the stainless steel components in containers exposed to worst-case conditions suggest that the rate of corrosion would not lead to through-wall penetration within a 40-year period. However, accelerated corrosion studies suggest that stress corrosion cracking could be a concern, and must be more fully understood. Therefore, we recommend conservatively a design life of 15 years for the stainless steel components to allow the accelerated corrosion studies to be completed and to collect additional surveillance data.