Puck Passive Loop Seal

Sandia National Laboratories (SNL) is advancing technical capabilities used in passive loop seals. The “Puck” seal uses a set of International Atomic Energy Agency (IAEA) requirements for new passive loop seals published in 2020 as a design guide. The seal is based on an oxygen-sensitive inner mixture encased in an oxygen-impermeable shell, is monolithic rather than two-part, incorporates self-capturing wire features, contains colored water beads and bubbles formed during processing as unique identifiers, and visually indicates tamper (whether from seal body penetration or from seal wire removal) by irreversibly changing the seal body from multi-colored to black. SNL is currently designing and developing prototypes of the Puck seal. Further, SNL is working together with Oak Ridge National Laboratory (ORNL) on another seal version, Puck/SAW, that uses the same seal body and incorporates a surface acoustic wave (SAW) chip that can monitor wire continuity and provide a unique identifier upon standoff interrogation. This paper will provide details on the design and development of Puck prototypes.