Experience with an ultrasonic sealing system for nuclear safeguards in irradiated fuel bay demonstrations

The development of the irradiated fuel safeguards containment assembly for CANDU nuclear generating stations has stimulated the development of the AECL Random Coil Sealing System. The ARC seal combines the identity and integrity elements in an ultrasonically-determined signature. This is verified in situ, in real time with the seal reading system. The maturation of this technology has been facilitated with demonstration trials in the NRU and NPD irradiated fuel bays. The NPD demonstration includes operation of the systems tooling by Ontario Hydro staff. It provides the opportunity for IAEA inspectors from Toronto and Vienna to direct the operational procedures and to perform the data acquisition. The procedures and systems developed in these trials are reviewed. The estimation of the system performance characteristics from the observations is presented. A minimum frequency of reading for individual seals is recommended to be once per annum following initial deployment