New attempt to assess interruption probability with sensor-signal variations

Terao, Norichika; Suzuki, Mitsutoshi

As a new trial on probabilistic risk assessment in nuclear security field, system effectiveness of physical protection is evaluated in terms of interruption probability considering variation of detection and communication performance. Although the Estimate of Adversary Sequence Interruption (EASI) developed by Sandia National Laboratory has been used worldwide, actual and realistic effect due to fluctuation of signals from sensors and monitoring cameras is not taken into account. Probability distribution of detection and communication variables is introduced into the EASI method to calculate the overall performance of interruption, and system effectiveness is investigated by using a hypothetical model of nuclear facility. Distribution of interruption probability is numerically calculated through detection and communication probabilities with a Monte Carlo method using the normal random number.