The role of uncertainty estimation on the improvement of measurement process and results comparison

Nuclear material measurements for mass fraction and isotopic abundance are routinely conducted in safeguards analytical laboratories. New analytical methods, changes in experimental techniques, modern instrumentation, and new software packages for calculation of results and measurement uncertainties are introduced towards making constant improvements. Scientists and technicians must adapt to these changes, keep up with the advancement, and ensure obtaining analyses results with improved accuracy and precision with correct evaluation of uncertainties. Furthermore, it is important to communicate the experimentally determined values and the uncertainties in such a manner so that all information associated with the reported results are fully understood not only by its originator, but also by other users with a need to work with those results. Standard methods (according to ISO guidelines) for calculating and expressing measurement uncertainty are given in several publications such as the 'Guide to Expression of Uncertainty in Measurement' (GUM) and the 'Quantifying Uncertainty in Analytical Measurements' (EURACHEM / CITAC Guide CG 4). Note that the evaluation of measurement uncertainty is also a central element in quality assurance programs. In this paper, we will discuss the importance of appropriate estimation of uncertainties with specific reference to improve measurement processes in nuclear material accountability measurements, and in evaluation of performance test results. (author)