Exploration of Ion-Exchanged Glass for Seals Applications

As the nuclear industry grows around the globe, it brings with it a need for more safeguards and proliferation resistant technologies. The International Atomic Energy Agency (IAEA) depends on effective containment and surveillance (C/S) technologies and methods for maintaining continuity of knowledge over nuclear assets. Tags and seals, a subset of C/S technologies, are an area where innovation has been relatively stagnant for the past fifteen years. It is necessary to investigate technologies not previously used in this field in order to defend against emerging threats and methods of defeat.

Based on a gap analysis of tags and seals currently being used by the IAEA, completed with the input of several subject matter experts, the technology selected for investigation was ion-exchanged glass. Ion-exchanged glass is relatively inexpensive, has high strength, and can be used in a variety of applications. If identical pieces of glass are exchanged under the same conditions and subjected to the same point load, the fracture patterns produced can be compared and used as a verification measure. This technology has the potential to be used in passive seal applications. Each image was categorized depending on its fracture as a "3 leaf" or "4 leaf" pattern. These two populations were separately analyzed and evaluated. Several methods used to analyze the fracture patterns involve the use of image analysis software such as ImageJ and the MATLAB Control Point Selection Tool. The statistical analysis software Minitab was used to validate the use of facture pattern analysis as verification tool. The analysis yielded a 60% verified comparison for samples demonstrating a "3 leaf" fracture pattern and a 78% verified comparison for samples with a "4 leaf" fracture pattern. This preliminary analysis provides a strong indication of the plausibility for the use of ion-exchanged glass as a verification measure for C/S measures and specifically tags and seals.