Year
2003
Abstract
A physical measurement without a statement of uncertainty or confidence level has little practical worth. The construction of a complete and justifiable uncertainty budget is therefore of fundamental importance. In this paper the Total Measurement Uncertainty (TMU) analysis approach for a collection of non-destructive assay techniques is examined for the purposes of accurately characterizing Transuranic wastes and defining the limitations toward their reliable disposition against an action level. Compared to less sophisticated systems, the use of a combined (or integrated) approach allows a greater range of matrix types and plutonium mass to be successfully assayed along with an overall reduction in the TMU. The application of this TMU approach to the Integrated Waste Assay System (a hybrid system combining quantitative high resolution gamma-ray spectroscopy, gamma-ray isotopic analysis, passive neutron coincidence counting, and differential die-away analysis) is discussed. Calculated TMU values for various matrices are presented with comparison to preliminary measured values.