Development of criteria and computerized procedures for safeguards performance evaluations

The evaluation of the effectiveness of Agency safeguards for a series of inspections at nuclear installations in a State is based on a set of comprehensive uniform criteria. These criteria translate the general safeguards objective of verifying nuclear material under safeguards in a timely manner into requirements for inspection and Headquarters activities necessary to attain the inspection goal. They specify the minimum sample sizes to be used for verification activities and the minimum frequencies with which the relevant activities must be carried out so that the detection capabilities of the Agency can be evaluated as providing for timely detection. The verification activities considered necessary to meet the inspection goal are graded in the criteria according to the safeguards relevance of a particular nuclear material type. The paper describes the main principles used in developing the criteria and contains a few examples of alternative sets of verification activities which can be used to attain the inspection goal. It also describes in some detail the arrangement of the system of computer programs which have been developed to realize the inspection goal attainment evaluations based on computerized inspection report data, and contains examples of how evaluation results are presented. (author)