Curium concentration in spent nuclear fuel

Neutron measurements are frequently used to characterize spent nuclear fuel. Curium is the primary neutron source from most spent nuclear fuel materials. Recent developments in nuclear safeguards measurements of spent nuclear fuel have increased the reliance upon curium assay for materials accounting on the back end of the fuel cycle. The curium assay is used to determine the fuel composition by the curium-ratio technique. The interpretation of these measurements is based upon the results of calculations using depletion codes. In this paper we will examine depletion code results to determine if there is reason for concern for the reliability of curium concentration from calculation.