Year
1986
Abstract
The Canadian Safeguards Support Program has developed .in underwater seal foi use with spent fuel containment. Ultrasound in conjunction with a randomly produced wire coil formulates the seal signature. In July 1985, false snd raissed aj.arr.1 estimates for the CANDl'-ARC seal were reported at the INMM. False alarm estimates were thought conservatively to be in the range of 1% to 3% at one year for an acceptance threshold of 0.7. The ruissed alarm probability was estimated to be 0.01% using an acceptance threshold of 0.61. These seal performance indicators were derived eir.piricplly from observations made during the teats conducted in the Nuclear Power Demonstration (NPP) reactor spent fuel bay. EaiOy in these tests, a downward trend in auto-correlation coefficients was observed. As the tests continued, auto-correlation coefficient's recovered to previous values and have remained stable to the present. From a statistical analysis of the cu>rent data base, it is new believed that the falet alarm probability if. 0.1% at a threshold of C.~4 and that, at this threshold, the missed alarr. probability is 0.03%.