A BAYESIAN APPROACH TO THE EVALUATION OF NUCLEAR MATERIAL SAFEGUARDS ACTIVITIES

A possible approach to the evaluation of accounting or inspection information is described which uses Bayes' Theorem to derive a probability distribution for the amount of material missing. This approach shows promise of providing a more useful description of all available data than current approaches which are based on obtaining a yes/no conclusion regarding the hypothesis that no material is missing. This Bayesian approach requires that each test be described by a response function which gives the relative probability of each posible result as a function of the true amount of material missing. Possible response functions for different types of tests are described and the effect of different test results on the final probability distribtuion is illustrated with numerical examples. This approach is particularly useful in that it allows the results of a diversity of tests (ranging from containment and surveillance activities to MUF or ID determination) to be treated in a unified analytical framework which shows promise of facilitating both the reporting and evaluation of inspection information.