To reduce the amount of weapons-grade nuclear waste present in the South Carolina, the Department of Energy (DOE) started an initiative to dilute and dispose of the state’s surplus plutonium. This disposition operation, occurring over the next 30 years, will process upwards of 120,000 Criticality Control Overpack (CCO) containers. Because of the high volume of CCOs being inspected and the duration of the project, the Savannah River Site (SRS) tasked Savannah River National Laboratory (SRNL) with automating the inspection of the CCOs while preserving the level of security in manual inspection operations. The final step in the inspection procedure is applying a Tamper Indicating Device (TID) to ensure the CCOs have not been altered since the inspection prior to loading with downblended plutonium. The TID used in manual operations is a pull-tight, wire cable TID and was unusable when paired with robotic automation, requiring the redesign of the TID and the design of an end-of-arm tool (EOAT) for the robot to apply the TID. Following several prototypes utilizing additive manufacturing and different materials, the latest iteration of the TID now consists of two disposable components: a plastic injection molded cage housing and a serialized aluminum pin. Batches of TIDs are loaded into the robotic work cell in cartridges that interface with the tooling, ensuring minimal operator intervention. The applicator tool, equipped with the housing and pin assembly, applies the TID assembly to the drum lid closure ring, presses the pin through the housing, and uses a punch form to expand the pin head, locking it in place. Once locked, the TID prevents the bolt from being loosened and the lid from being removed unless the aluminum pin or housing is destroyed. The robot captures the serial number, adding it to the data package for the CCO container, which is verified when removing the TID and reopening the CCO for loading after inspection. The deformed end of the pin is also scanned and evaluated by the robot to ensure a proper locking seal. Recent improvements to the TID and process include cost savings by switching to plastic injection molding for the housing from previous additive manufacturing and machined solutions, the development of an automated TID feeder, and the approval of the TID by Material Control & Access (MC&A). The TID is a novel, mass-produced, scalable assembly that is designed to be integrated with the robotic automation process; this allows the last step of the inspection process to be completed without human involvement. The automated installation of the TID ensures the security of the CCOs from the completion of the inspection to the plutonium downblending facility, ensuring the safe management of nuclear material packaging and that security is not compromised throughout the disposition process.
Year
2024
Abstract