Field evaluation of a sealing system for CANDU spent fuel

The International Atomic Energy Agency, with the assistance of the Canadian Safeguards Support Programme and Hydro Quebec, have carried out a 16-month intensive field trial, under routine use conditions, of a sealing system for irradiated fuel in an operating CANDU 600 MW(e) power reactor. The sealing system evaluated was composed of the ARC (AECL Random Coil) ultrasonic seal, a micro-processor-based interrogator called the SPAR (SEAL PAttern Reader), and a suitable containment structure. The test evaluated the hardware and software of the system, the effort required for the application, verification and maintenance of the seals, and the containment structure. Also evaluated were the sealing procedures, role of the facility operator, the need for training of both inspectors and facility personnel, interference with routine activities at the facility, and the overall logistics of the system from procurement of components to management of a seal information database. The stability of the seal signatures over the long term was examined. False and missed alarm rates were calculated. The feasibility of verification of the underwater containment structure was demonstrated. The overall results are good, and the system was demonstrated to be a workable and reliable one.