Weapon parts are packed in dense polyurethane foam. After workers noticed discrepancies in that material, Y‑12 revamped a long-established foam manufacturing and inspection process.
Assembly workers in Y‑12’s container refurbishment shop raised a concern last year that quickly put the brakes on weapon shipments across the country. Foam inserts, manufactured at Y‑12 and used in packaging containers to cushion parts and materials during shipping, seemed to vary in weight, sometimes greatly.
Dedicated personnel in this small group inspect returned shipping containers for reuse. Parts, including drums, bolts, labels, inner containment vessels and foam, are inspected and, when possible, refurbished for reuse. Some containers, like the popular DT series, have been in use since 1991.
“In the past, only visual inspections were performed on the foam parts,” said the container refurbishment supervisor. “Now, Y‑12’s made several improvements to ensure foam is not only manufactured to meet design requirements but also verified through dimensional inspection and tracked.”
All elements of the process related to packaging foam were scrutinized. Productivity Improvement lead Amy Duncan assisted the team by identifying key quality control points through process mapping. The changes resulted in a process with an acceptance rate that is greater than 98 percent for foam production.
Procured raw materials are now more strictly specified. New aluminum molds were designed, then machined and are now used during the foam manufacturing process. The new molds have better placement and sizing of the vent holes, which allow gases to be controllably released, reducing voids and creating a more consistent and predictable density in the material. Also, the molds are preheated for a prescribed length of time, which also influences density. Newly fabricated foam is now dimensionally inspected and weighed to ensure that the product meets specifications. Once certified, each foam piece is assigned a unique number, which is stenciled on the foam and entered into a database. Pieces are now tracked from cradle to grave.
After foam manufacturing was reworked, shipments needed to be approved for restart by the National Nuclear Security Administration’s Office of Packaging and Transportation. All modifications made to foam underwent structural, thermal, shielding and criticality evaluations in conjunction with the content (weapon system) and packaging (container type). To allow shipments to resume, five unscheduled safety analysis reports for packaging were revised to include a broader foam density range to accommodate flexibility in the foam manufacturing.
The NNSA Production Office recognized Y‑12’s efforts to identify and address the foam production improvements. In an issues-management report, NPO said the Y‑12 Packaging Program has driven substantial progress and credited the integration of quality hold points for reducing foam component defects. NPO stated that these actions provided a credible process for Y‑12 to manufacture Type B foam components that meet defined safety analysis report requirements.
“This time last year, we weren’t producing foam because of quality issues,” Y‑12 President and General Manager Dave Richardson recently explained to Y‑12’s managers and front-line supervisors. “But we confronted the problem head-on and delivered a solution that addresses long-term corrective actions.”