Manufacturing Process Capability Analysis for SAVY-4000 Nuclear Material Storage Container Quality Assurance

Inc., is now being produced for use in nuclear facilities across the Department of Energy Complex. The SAVY-4000 is a simple, robust, and reusable container for storing solid nuclear materials inside nuclear facilities. The container is made primarily of 316L stainless steel to minimize corrosion and to prevent release in an accidental drop, it relies on a Viton® O-ring seal, and it includes a filter to prevent particulate release and to facilitate the release of hydrogen, thus preventing flammable gas mixtures from forming and ensuring that only minimal pressure is possible within the container during use. Thus, the container is not a pressure vessel but a light weight, worker-friendly container that is readily opened and closed. In the early stages of container production, it is important to establish process capability baselines for the various manufacturing processes. As part of the quality assurance program for container production, both in-process and final inspection data have been collected for the filter (particulate removal efficiency, hydrogen diffusion, pressure drop, and water penetration), the O-ring seal (helium leak rate, groove dimensions, and surface roughness), and the welds (penetration depth, solidification mode, and dye penetrate examination). This presentation will include a description of the statistical sampling methodology, an analysis of the manufacturing data collected in the early stages of production, and an overall assessment of the manufacturing process capability. These results will be used to establish appropriate statistical process control limits for future container production and to establish a baseline for the container surveillance program at Los Alamos National Laboratory.