Stochastic Approach to Inspection Evaluation: Methodology and Validation

Volume: 64, issue 1, June 2022, pages 30-38

Authors: Lohith Annadevula¹, S. K. Aghara¹, Kenneth Jarman² and Logan Joyce¹

¹_{University of Massachusetts Lowell,} ²_{Pacific Northwest National Laboratory}

Abstract:The paper discusses the methodology for performing International Atomic Energy Agency’s (IAEA’s) postinspection analysis to assess the ef fectiveness of verification inspection plans using a stochastic method. Conventionally, well-established statistical distributions are employed to calculate Detection Probability (DP) which is the effectiveness metric for both planning and evaluation purposes. The detection probability here is the probability of detecting at least one “defective” item (an item from which material has been removed) from the multi-defect sample space of items. The DP, in turn depends on the probability that a defected item is randomly selected for measurement (the “selection probability”) and the probability that the applied measurement identifies the defect (the “identification probability”). The stochastic method described here involves simulating the inspection process by randomly choosing a fixed number of items from a population of items and performing measurements for these samples. A detection probability value is calculated at the end of a simulation depending on the random outcome. Multiple such simulations/trials are performed on the same sample space to get multiple detection probabilities. The Final Detection Probability and its uncertainty are estimated by computing the average and standard error of all the DP values from all simulations. The stochastic model development, its verification, and benchmarking are discussed in detail.

Keywords: Stochastic Approach; Detection Probability; Selection Process

Reference guideline:

Annadevula, L., Aghara, S.K., Jarman, K., & Joyce, L. (2022, June). Stochastic Approach to Inspection Evaluation: Methodology and Validation. ESARDA Bulletin - The International Journal of Nuclear Safeguards and Non-proliferation, 64(1), 30-38. https://doi.org/10.3011/ESARDA.IJNSNP.2022.3